The Climates of the North Coast: Focus on Lake County

Gregory V. Jones Department of Environmental Studies June 4, 2013 Outline of Talk

. Overview of the General Climate Characteristics of the Western US, the North Coast, and Lake County . West Coast Climate Variability Mechanisms . Current Situation and 2013 Vintage Forecast Climate Influences, Risks, and Challenges Weather and Climate present three distinct spatial and temporal scales of influences and risks to viticulture and wine production:

. Individual Weather Events (short-term/localized) Crop Risk – Hail, frost/freezes, heavy rain, etc.

Production . Climate Variability (seasonal-decadal/regionalized) – Dry or wet & warm or cold periods & Quality Variability

. Climate Structure/Change (long-term/regional-global) – Average & extreme temperatures, rainfall regimes Suitability – Warming, cooling, changes in moisture regimes

Climate Structure of the Western US, the North Coast, and Lake County Spatial Analysis in Winegrape Growing Regions in the Western US

–Digitized AVA Boundaries –131 complete AVAs used (approved or pending as of 2008) –Produced complete AVA area, elevation, and climate index summaries (10-400 m resolution) –Examined the usefullness of different climate indices in the Western US –Similar work is done or in process for other wine regions worldwide

Jones et al. (AJEV: Sept 2010, 61:313-326) Growing Degree-Days (1971-2000)

. General AVA Statistics: – Overall median GDD = 3087 – Lowest median GDD = 1530 – Highest median GDD = 4520 – Median class structure over all AVAs: Class Count % (Region I) 1500-2500 23 17.0 Growing Degree-Days (Base 50°F, Apr-Oct) (Region II) 2500-3000 34 25.2 < 1500 (Region III) 3000-3500 44 32.6 1500 – 2500 (Region I) 2500 – 3000 (Region II) (Region IV) 3500-4000 25 18.5 3000 – 3500 (Region III) (Region V) 4000-4900 9 6.7 3500 – 4000 (Region IV) 4000 – 4900 (Region V) > 4900 . Spatial distribution within AVAs depends on elevation differences, and proximity and orientation to coast . Temporal distribution is +/- 325-500 GDD off the median (>75% of the time)

Jones et al. (AJEV: Sept 2010, 61:313-326) AVA Growing Degree-Days Distributions Histogram of Winkler Region GDD Cells by AVA Histogram of Winkler Region GDD Cells by AVA 1100 6000 1000 900 5000 GDD 1% Region I 30% Region IV GDD 800 < 850 < 850 700 100% Region I 4000 12% Region II 1% Region V 850 - 1389 850 - 1389 600 30001389 - 166756% Region III 1389 - 1667 500 1667 - 1944 1667 - 1944 400 20001944 - 2222 GDD1944 - 2222 300 2222 - 2700 2222 - 2700

NumberCellsGrid of 200 NumberCellsGrid of 1000> 2700 > 2700 100 < 1500 0 0 1500 - 2500 HistogramEola-Amity of WinklerEola-Amity Region Hills GDD AVA Cells AVA by AVA HistogramNapa of Winkler NapaValley Region Valley GDD AVA AVA Cells by AVA 25000 7000 2500 - 3000 6000 3000 - 3500 20000 GDD GDD 2% Too Cold 5000 14% Region II < 850 < 850 3500 - 4000 15000 78% Region I 4000850 - 138949% Region III 850 - 1389 1389 - 1667 1389 - 1667 10000 20% Region II 30001667 - 194437% Region IV 1667 - 40001944 - 4900 1944 - 2222 1944 - 2222 20002222 - 2700 2222 - >2700 4900 5000 NumberCellsGrid of NumberCellsGrid of 1000> 2700 > 2700

0 0

HistogramRogue of WinklerRogue RegionValley Valley GDD AVA AVA Cells by AVA HistogramPaso of Winkler PasoRobles Region Robles GDD AVA AVA Cells by AVA 7000 9000

6000 8000 7000GDD GDD 5000 6000< 850 < 850 850 - 1389 850 - 1389 4000 18% Region I 5000 78% Region IV 1389 - 1667 1389 - 1667 3000 82% Region II 40001667 - 194412% Region V 1667 - 1944 30001944 - 2222 1944 - 2222 2000 2222 - 2700 2222 - 2700 Growing Degree-Days 2000 (Base 50°F, Apr-Oct) NumberCellsGrid of 1000 NumberCellsGrid of > 2700 > 2700 < 1500 1000 1500 – 2500 (Region I) 2500 – 3000 (Region II) 0 0 3000 – 3500 (Region III) 3500 – 4000 (Region IV)

4000 – 4900 (Region V)

> 4900 HistogramWalla of WallaWinklerWalla Walla Region Valley Valley Cells AVA byAVA AVA Histogram of WinklerLodi RegionLodi AVA AVA GDD Cells by AVA 900 12000 800 10000 700 26% Region I GDD GDD 600 58% Region II 8000< 850 100% Region V < 850 850 - 1389 850 - 1389 500 16% Region III 60001389 - 1667 1389 - 1667 400 1667 - 1944 1667 - 1944 300 40001944 - 2222 1944 - 2222 2222 - 2700 200 2222 - 2700 NumberCellsGrid of NumberCellsGrid of 2000> 2700 > 2700 100 0 0 AndersonAnderson Valley Valley AVA AVA MaderaMadera AVA AVA Jones et al. (AJEV: Sept 2010, 61:313-326) Elevation (ft) Area1 AVA AVA Name (hectares) Median Max Min Range Benmore Valley 580 2598 2795 2116 679 Area (ha) Red Hills Lake County 12560 2037 3611 1381 2230 High Valley 6970 1971 3339 1332 2007 Howell Mountain 5300 1745 2552 1027 1525 and Covelo 16210 1597 2699 1397 1302 Cole Ranch 80 1555 1719 1496 223 Clear Lake 88750 1548 3956 1309 2647 Elevation (ft) Atlas Peak 5040 1512 2470 856 1614 Dos Rios 6760 1460 2726 823 1902 Mendocino Ridge 33970 1407 2558 459 2099 Rockpile 5970 1401 2227 800 1427 Spring Mountain District 3440 1358 2293 531 1761 York Mountain 2590 1332 1814 1086 728 Mendocino 71540 1230 3736 407 3329 Wild Horse Valley 1600 1223 1620 830 790 Potter Valley 11760 1155 3021 892 2129 Redwood Valley 13050 1148 2404 797 1607 Mt. Veeder 6880 1115 2549 367 2181 Guenoc Valley 1700 1059 1581 974 607 Chiles Valley 2600 1027 1633 797 836 Capay Valley 40140 1007 2926 197 2729 Diamond Mountain 2010 1004 2083 531 1551 North Coast 1323670 981 5330 0 5330 Sonoma Mountain 2350 876 1784 479 1305 Knights Valley 15110 843 3890 213 3677 Napa Valley 162390 813 3854 0 3854 McDowell Valley 910 804 1036 604 433 Dry Creek Valley 31540 794 2326 82 2244 Sonoma Valley 47020 738 2398 0 2398 Anderson Valley 23620 712 1758 197 1561 Bennett Valley 3370 705 1568 249 1319 Northern Sonoma 130850 633 3890 82 3808 Alexander Valley 31690 485 2447 157 2289 Calistoga 5180 469 1273 282 991 Solano Co Green Valley 5650 453 2011 16 1994 Chalk Hill 9140 338 403 338 66 St. Helena 3730 292 646 194 453 Sonoma Co Green Valley 7720 289 810 92 718 Yountville 3370 266 1174 59 1115 Sonoma Coast 212390 249 2145 0 2145 Russian River Valley 63170 203 1437 49 1387 Dunnigan Hills 27120 197 400 46 354 Coombsville 4640 187 1483 3 1479 Rutherford 3030 180 912 157 754 Oakville 2810 167 912 157 754 Stags Leap District 1240 112 417 66 351 Los Carneros 15130 95 1246 0 1246 Oak Knoll District 4010 92 886 23 863 Susiun Valley 6670 79 518 3 515 Area (ha) Elevation (ft) Area and AVA Name (ha) Elevation (ft) Median Max Min Range Benmore Valley 580 2598 2795 2116 679

Guenoc Valley 1700 1059 1581 974 607

High Valley 6970 1971 3339 1332 2007

Red Hills Lake County 12560 2037 3611 1381 2230

Clear Lake 88750 1548 3956 1309 2647

. ~200 growers . ~8500 acres planted . The majority of the vineyards are planted above 1,500 ft . Cabernet Sauvignon, Sauvignon Blanc, Petite Sirah, Merlot, Syrah, Cabernet Franc, Zinfandel, Tempranillo, Chardonnay, Riesling, and many other varieties planted . ~35 wineries Growing Degree-Days (base 50°F) AVA Growing AVA Name Min 25% Median 75% Max Range Sonoma Coast 850 2304 2596 2754 3404 2554 Degree-Days Sonoma Co Green Valley 2560 2669 2693 2707 2774 214 Mendocino Ridge 1951 2479 2701 2795 3069 1118 Russian River Valley 2425 2686 2736 2770 3233 808 (F° units) Anderson Valley 2257 2520 2759 2934 3191 934 Bennett Valley 2637 2831 2860 2909 3069 432 Median = 3218 Yorkville Highlands 2639 2797 2882 3087 3456 817 North Coast 736 2655 2938 3224 4034 3298 Stdev = 321 Chalk Hill 2768 2882 2941 3029 3386 617 Los Carneros 2695 2867 2947 3069 3649 954 Max = 4217 Dos Rios 2848 2929 2963 3002 3308 461 Northern Sonoma 1903 2758 3002 3157 3541 1638 Min = 2596 Howell Mountain 2894 2986 3015 3092 3537 643 Sonoma Valley 2468 2878 3017 3139 3431 963 Range = 1622 Covelo 2772 2965 3020 3101 3258 486 Redwood Valley 2675 2916 3035 3211 3332 657 Rockpile 2952 3044 3074 3116 3254 302 Potter Valley 2779 2981 3076 3206 3278 499 Cole Ranch 3062 3065 3084 3103 3103 41 Atlas Peak 2601 2983 3098 3164 3562 961 Dry Creek Valley 2617 3020 3103 3163 3280 662 Alexander Valley 2738 3069 3134 3213 3523 785 Mendocino 2680 3083 3193 3283 3683 1003 Spring Mountain District 2936 3098 3213 3413 3541 605 Knights Valley 1903 2959 3218 3287 3541 1638 McDowell Valley 3134 3217 3244 3269 3305 171 Sonoma Mt. 2848 3125 3245 3311 3404 556 Benmore Valley 3155 3242 3248 3257 3332 176 Oak Knoll District 3040 3170 3253 3312 3501 461 Clear Lake 2799 3209 3267 3442 3811 1012 Chiles Valley 3019 3222 3312 3429 3555 536 Diamond Mountain 2952 3272 3343 3409 3501 549 Coombsville 2947 3210 3360 3616 3926 979 Mt. Veeder 2468 3186 3370 3465 3667 1199 Napa Valley 2036 3155 3389 3546 4023 1987 Rutherford 3364 3388 3411 3449 3575 211 St. Helena 3366 3377 3413 3460 3595 229 Yountville 3218 3355 3416 3469 3587 369 Calistoga 3193 3362 3422 3467 3517 324 Oakville 3240 3410 3434 3479 3584 344 Guenoc Valley 3420 3465 3481 3580 3796 376 Stags Leap District 3321 3461 3532 3583 3845 524 High Valley 3139 3447 3548 3618 3755 616 Red Hills Lake County 3114 3434 3596 3683 3776 662 Susiun Valley 3449 3549 3624 3762 4027 578 Wild Horse Valley 3244 3510 3631 3672 3895 652 Solano Co Green Valley 3202 3568 3746 3868 4021 819 Capay Valley 2963 3730 3866 4065 4318 1355 Dunnigan Hills 4093 4192 4217 4243 4343 250 Growing Degree-Days (base 50°F) Covelo AVA Growing AVA Name Min 25% Median 75% Max Range Sonoma Coast 850 2304 2596 2754 3404 2554 Laytonville Degree-Days Sonoma Co Green Valley 2560 2669 2693 2707 2774 214 Mendocino Ridge 1951 2479 2701 2795 3069 1118 Russian River Valley 2425 2686 2736 2770 3233 808 (F° units) Anderson Valley 2257 2520 2759 2934 3191 934 Bennett Valley 2637 2831 2860 2909 3069 432 Median = 3218 Yorkville Highlands 2639 2797 2882 3087 3456 817 Willits North Coast 736 2655 2938 3224 4034 3298 Stdev = 321 Chalk Hill 2768 2882 2941 3029 3386 617 Los Carneros 2695 2867 2947 3069 3649 954 Max = 4217 Dos Rios 2848 2929 2963 3002 3308 461 Northern Sonoma 1903 2758 3002 3157 3541 1638 Min = 2596 Howell Mountain 2894 2986 3015 3092 3537 643 Sonoma Valley 2468 2878 3017 3139 3431 963 Ukiah Range = 1622 Covelo 2772 2965 3020 3101 3258 486 Redwood Valley 2675 2916 3035 3211 3332 657 Rockpile 2952 3044 3074 3116 3254 302 Potter Valley 2779 2981 3076 3206 3278 499 Cole Ranch 3062 3065 3084 3103 3103 41 Clearlake Atlas Peak 2601 2983 3098 3164 3562 961 Dry Creek Valley 2617 3020 3103 3163 3280 662 Alexander Valley 2738 3069 3134 3213 3523 785 Cloverdale Mendocino 2680 3083 3193 3283 3683 1003 Spring Mountain District 2936 3098 3213 3413 3541 605 Knights Valley 1903 2959 3218 3287 3541 1638 McDowell Valley 3134 3217 3244 3269 3305 171 Sonoma Mt. 2848 3125 3245 3311 3404 556 Healdsburg Benmore Valley 3155 3242 3248 3257 3332 176 Oak Knoll District 3040 3170 3253 3312 3501 461 Clear Lake 2799 3209 3267 3442 3811 1012 St Helena Chiles Valley 3019 3222 3312 3429 3555 536 Santa Rosa Diamond Mountain 2952 3272 3343 3409 3501 549 Coombsville 2947 3210 3360 3616 3926 979 Mt. Veeder 2468 3186 3370 3465 3667 1199 Napa Valley 2036 3155 3389 3546 4023 1987 Napa Rutherford 3364 3388 3411 3449 3575 211 Petaluma St. Helena 3366 3377 3413 3460 3595 229 Yountville 3218 3355 3416 3469 3587 369 Calistoga 3193 3362 3422 3467 3517 324 Oakville 3240 3410 3434 3479 3584 344 Guenoc Valley 3420 3465 3481 3580 3796 376 Stags Leap District 3321 3461 3532 3583 3845 524 High Valley 3139 3447 3548 3618 3755 616 Red Hills Lake County 3114 3434 3596 3683 3776 662 Susiun Valley 3449 3549 3624 3762 4027 578 Wild Horse Valley 3244 3510 3631 3672 3895 652 Solano Co Green Valley 3202 3568 3746 3868 4021 819 Capay Valley 2963 3730 3866 4065 4318 1355 Dunnigan Hills 4093 4192 4217 4243 4343 250 Growing Degree-Days

Growing Degree-Days (base 50°F) AVA Name Min 25% Median 75% Max Range

Benmore Valley 3155 3242 3248 3257 3332 176

Clear Lake 2799 3209 3267 3442 3811 1012

Guenoc Valley 3420 3465 3481 3580 3796 376

High Valley 3139 3447 3548 3618 3755 616

Red Hills Lake County 3114 3434 3596 3683 3776 662 Shape and Characteristics of GDD Accumulation

630 Similar peak Bordeaux 2767 accumulation, but one 540 Oakville 3247 achieves it via lower DTR (↓ Tmax, ↑ Tmin), the other via a higher 450 DTR (↑ Tmax, ↓ Tmin) F base) F

° 360

One region has early 270 accumulation which drives earlier growth

180 Growing Degree-Days (50 Degree-Days Growing 90 Similar harvest dates but one has a cooler ripening window 0 1 2 3 4 5 6 7 8 9 10 11 12 Month (Jan-Dec)

Unpublished Data GDD - North Coast and Surrounding Area 1000 ANGWIN 1981-2010 Climate Normals BODEGA CALISTOGA 900 Mean 3210 CLEARLAKE CLOVERDALE Stdev 894 COLUSA 800 COVELO Max 4691 EAST PARK RSVR FAIRFIELD

FT BRAGG Min 934 700 FT ROSS F) ° Range 3756 GRATON HEALDSBURG 600 LAKE SOLANO MARKLEY COVE

NAPA CO AP

NAPA STATE HOSPITAL Days (Base 50(Base Days

- 500 OCCIDENTAL

PETALUMA

POTTER VALLEY 400 SAINT HELENA SAN RAFAEL

SANTA ROSA SONOMA CO AP

SANTA ROSA

Growing DegreeGrowing 300 SONOMA

STONY GORGE RSVR

UKIAH FAA AP 200 UKIAH VACAVILLE

WARM SPRINGS DAM

WILLITS

100 WILLOWS

WINTERS

YOUNTVILLE 0 Average Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec AVA Name Median Max Min Range Covelo AVA Last Covelo 2-May 15-May 24-Apr 21 Dos Rios 29-Apr 9-May 17-Apr 22 Laytonville Spring Frost Redwood Valley 18-Apr 1-May 3-Apr 28 Clear Lake 16-Apr 1-May 22-Mar 40 Potter Valley 15-Apr 27-Apr 7-Apr 20 (date/days) Cole Ranch 11-Apr 11-Apr 8-Apr 3 Guenoc Valley 7-Apr 10-Apr 18-Mar 23 Median = 15-Mar Atlas Peak 6-Apr 21-Apr 19-Mar 33 Willits Mendocino 5-Apr 25-Apr 10-Mar 46 Stdev = 17.9 Benmore Valley 3-Apr 7-Apr 2-Apr 5 Mendocino Ridge 3-Apr 17-Apr 27-Feb 49 Max = 2-May Howell Mountain 3-Apr 7-Apr 19-Mar 19 High Valley 2-Apr 23-Apr 23-Mar 31 Min = 16-Feb McDowell Valley 2-Apr 6-Apr 29-Mar 8 Red Hills Lake County 1-Apr 19-Apr 23-Mar 27 Ukiah Range = 75 Yorkville Highlands 31-Mar 13-Apr 4-Mar 40 Chiles Valley 30-Mar 6-Apr 17-Mar 20 Anderson Valley 27-Mar 12-Apr 14-Mar 29 Diamond Mountain 24-Mar 29-Mar 17-Mar 12 Calistoga 24-Mar 29-Mar 15-Mar 14 Clearlake North Coast 23-Mar 15-May 24-Jan 111 Spring Mountain District 22-Mar 30-Mar 13-Mar 17 Napa Valley 19-Mar 30-Apr 31-Jan 89 Cloverdale Mt. Veeder 15-Mar 30-Apr 15-Feb 74 Knights Valley 15-Mar 12-May 3-Mar 70 Capay Valley 13-Mar 16-Apr 18-Feb 57 St. Helena 13-Mar 26-Mar 10-Mar 16 Wild Horse Valley 12-Mar 2-Apr 24-Feb 37 Healdsburg Rockpile 12-Mar 27-Mar 7-Mar 20 Sonoma Mt. 11-Mar 22-Mar 1-Mar 21 Sonoma Co Green Valley 11-Mar 16-Mar 4-Mar 12 Santa Rosa St Helena Sonoma Valley 10-Mar 30-Apr 11-Feb 78 Chalk Hill 10-Mar 12-Mar 8-Mar 4 Rutherford 9-Mar 12-Mar 7-Mar 5 Oakville 8-Mar 21-Mar 3-Mar 18 Northern Sonoma 7-Mar 11-May 19-Feb 81 Napa Stags Leap District 6-Mar 13-Mar 4-Mar 9 Petaluma Dry Creek Valley 6-Mar 25-Mar 19-Feb 34 Yountville 5-Mar 19-Mar 23-Feb 24 Bennett Valley 5-Mar 18-Mar 25-Feb 21 Alexander Valley 5-Mar 29-Mar 24-Feb 33 Russian River Valley 5-Mar 16-Mar 21-Feb 23 Sonoma Coast 4-Mar 16-Apr 3-Feb 72 Coombsville 1-Mar 24-Mar 23-Feb 29 Oak Knoll District 28-Feb 5-Mar 25-Feb 8 Solano Co Green Valley 20-Feb 3-Apr 15-Feb 47 Los Carneros 20-Feb 14-Mar 9-Feb 33 Susiun Valley 16-Feb 24-Feb 10-Feb 14 Dunnigan Hills 16-Feb 1-Mar 8-Feb 21 Last Spring Frost (date/days)

AVA Name Median Max Min Range

Clear Lake 16-Apr 1-May 22-Mar 40

Guenoc Valley 7-Apr 10-Apr 18-Mar 23

Benmore Valley 3-Apr 7-Apr 2-Apr 5

High Valley 2-Apr 23-Apr 23-Mar 31

Red Hills Lake County 1-Apr 19-Apr 23-Mar 27 AVA Name Median Max Min Range Covelo AVA First Covelo 22-Oct 20-Nov 15-Oct 36 Dos Rios 25-Oct 21-Nov 15-Oct 37 Laytonville Fall Frost Clear Lake 3-Nov 7-Dec 22-Oct 46 Potter Valley 3-Nov 1-Dec 26-Oct 36 Redwood Valley 5-Nov 21-Nov 21-Oct 31 (date/days) Guenoc Valley 10-Nov 4-Dec 6-Nov 28 McDowell Valley 12-Nov 18-Nov 10-Nov 8 Median = 29-Nov Sonoma Co Green Valley 14-Nov 3-Dec 11-Nov 22 Willits Mendocino 15-Nov 13-Dec 25-Oct 49 Stdev = 11.8 Cole Ranch 17-Nov 18-Nov 16-Nov 2 Anderson Valley 18-Nov 25-Nov 7-Nov 18 Max = 13-Dec Mendocino Ridge 19-Nov 30-Dec 2-Nov 58 Calistoga 19-Nov 8-Dec 15-Nov 23 Min = 22-Oct Russian River Valley 22-Nov 19-Dec 10-Nov 39 North Coast 25-Nov 1-Jan 15-Oct 78 Ukiah Range = 52 High Valley 25-Nov 4-Dec 28-Oct 37 Yorkville Highlands 26-Nov 15-Dec 7-Nov 38 Atlas Peak 26-Nov 7-Dec 6-Nov 31 St. Helena 26-Nov 6-Dec 19-Nov 17 Rutherford 26-Nov 9-Dec 25-Nov 14 Clearlake Capay Valley 27-Nov 10-Dec 7-Nov 33 Oakville 27-Nov 10-Dec 25-Nov 15 Red Hills Lake County 28-Nov 4-Dec 27-Oct 38 Cloverdale Alexander Valley 28-Nov 18-Dec 22-Nov 26 Sonoma Coast 29-Nov 1-Jan 15-Oct 78 Chiles Valley 29-Nov 14-Dec 13-Nov 31 Yountville 29-Nov 21-Dec 27-Nov 24 Northern Sonoma 30-Nov 26-Dec 19-Oct 68 Healdsburg Howell Mountain 30-Nov 9-Dec 22-Nov 17 Diamond Mountain 30-Nov 9-Dec 15-Nov 24 Stags Leap District 30-Nov 12-Dec 28-Nov 14 Santa Rosa St Helena Dry Creek Valley 30-Nov 20-Dec 18-Nov 32 Chalk Hill 30-Nov 4-Dec 25-Nov 9 Dunnigan Hills 1-Dec 4-Dec 25-Nov 9 Oak Knoll District 1-Dec 12-Dec 29-Nov 13 Knights Valley 1-Dec 11-Dec 14-Nov 27 Napa Napa Valley 2-Dec 1-Jan 15-Nov 47 Petaluma Spring Mountain District 3-Dec 11-Dec 20-Nov 21 Los Carneros 3-Dec 1-Jan 6-Dec 26 Coombsville 5-Dec 26-Dec 26-Nov 30 Susiun Valley 6-Dec 26-Dec 3-Dec 23 Sonoma Valley 6-Dec 27-Dec 14-Nov 43 Sonoma Mt. 7-Dec 16-Dec 27-Nov 19 Solano Co Green Valley 8-Dec 29-Dec 6-Dec 23 Benmore Valley 8-Dec 8-Dec 6-Dec 2 Mt. Veeder 8-Dec 27-Dec 15-Nov 42 Wild Horse Valley 10-Dec 26-Dec 20-Nov 36 Rockpile 13-Dec 20-Dec 15-Nov 35 Bennett Valley 13-Dec 20-Dec 30-Nov 20 First Fall Frost (date/days)

AVA Name Median Max Min Range

Clear Lake 3-Nov 7-Dec 22-Oct 46

Guenoc Valley 10-Nov 4-Dec 6-Nov 28

High Valley 25-Nov 4-Dec 28-Oct 37

Red Hills Lake County 28-Nov 4-Dec 27-Oct 38

Benmore Valley 8-Dec 8-Dec 6-Dec 2 AVA Name Median Max Min Range Covelo AVA Frost Covelo 173 205 155 50 Dos Rios 179 221 163 58 Laytonville Free Period Clear Lake 200 260 174 86 Redwood Valley 203 222 176 46 Potter Valley 203 236 182 54 (days) Guenoc Valley 216 261 211 50 Cole Ranch 220 223 219 4 Median = 259 McDowell Valley 224 230 219 11 Willits Mendocino 227 278 184 94 Stdev = 28 Mendocino Ridge 229 302 203 99 Atlas Peak 234 263 200 63 Max = 293 High Valley 236 255 190 65 Anderson Valley 236 256 211 45 Min = 173 Calistoga 240 268 235 33 Red Hills Lake County 241 255 193 62 Ukiah Range = 120 Howell Mountain 241 265 229 36 Yorkville Highlands 241 285 210 75 Chiles Valley 243 272 222 50 North Coast 248 335 155 180 Benmore Valley 248 250 243 7 Clearlake Sonoma Co Green Valley 249 268 240 28 Diamond Mountain 251 265 236 29 Spring Mountain District 255 272 243 29 Cloverdale Knights Valley 258 282 187 95 Capay Valley 259 285 213 72 St. Helena 259 271 239 32 Napa Valley 259 335 199 136 Rutherford 262 275 259 16 Healdsburg Russian River Valley 263 298 240 58 Oakville 264 273 259 14 Chalk Hill 265 267 262 5 Santa Rosa St Helena Mt. Veeder 268 310 199 111 Sonoma Valley 268 313 199 114 Yountville 269 300 257 43 Stags Leap District 269 283 265 18 Sonoma Mt. 269 290 256 34 Napa Alexander Valley 269 290 255 35 Petaluma Northern Sonoma 269 304 279 25 Dry Creek Valley 270 304 243 61 Sonoma Coast 271 321 155 166 Wild Horse Valley 272 305 232 73 Oak Knoll District 275 290 270 20 Rockpile 277 286 233 53 Coombsville 281 302 247 55 Bennett Valley 283 297 263 34 Los Carneros 286 321 311 10 Dunnigan Hills 288 299 270 29 Solano Co Green Valley 291 316 302 14 Susiun Valley 293 311 283 28 Frost Free Period (days)

AVA Name Median Max Min Range

Clear Lake 200 260 174 86

Guenoc Valley 216 261 211 50

High Valley 236 255 190 65

Red Hills Lake County 241 255 193 62

Benmore Valley 248 250 243 7 AVA Name Median Max Min Range Covelo AVA Annual Dunnigan Hills 20.4 21.5 19.8 1.6 Capay Valley 22.4 35.3 19.6 15.7 Laytonville Precipitation Susiun Valley 22.7 26.6 20.8 5.8 Solano Co Green Valley 25.0 38.1 21.4 16.8 Coombsville 27.0 34.3 26.3 8.0 (inches) Los Carneros 27.2 42.9 23.1 19.7 Oak Knoll District 27.5 33.5 26.3 7.2 Median = 41.1 Stags Leap District 28.0 29.6 26.9 2.7 Yountville 31.3 39.6 26.8 12.9 Willits Stdev = 8.3 High Valley 33.6 54.1 28.3 25.7 Wild Horse Valley 33.6 38.0 29.8 8.2 Max = 57.4 Napa Valley 33.7 58.0 22.2 35.8 Oakville 33.7 37.4 30.7 6.7 Min = 20.4 Clear Lake 33.9 65.4 25.0 40.4 Rutherford 34.3 37.8 33.5 4.3 Ukiah Range = 37.0 St. Helena 35.6 38.1 34.0 4.1 Chiles Valley 37.6 39.4 31.0 8.3 Atlas Peak 37.9 39.9 30.9 9.0 Calistoga 39.5 44.2 35.7 8.5 McDowell Valley 39.8 41.5 38.7 2.8 Clearlake Red Hills Lake County 39.9 64.1 25.9 38.2 Sonoma Coast 40.7 78.1 23.1 55.0 Russian River Valley 40.8 60.9 31.5 29.3 Cloverdale Chalk Hill 40.9 41.1 39.8 1.3 Mt. Veeder 41.1 51.7 32.1 19.6 Diamond Mountain 41.7 48.4 37.4 11.0 Howell Mountain 42.3 46.9 37.7 9.1 Knights Valley 42.3 57.5 38.8 18.7 Healdsburg Anderson Valley 42.4 51.6 39.0 12.6 Guenoc Valley 42.8 44.8 40.5 4.3 Sonoma Valley 42.8 57.4 23.2 34.2 Santa Rosa St Helena Alexander Valley 42.8 51.7 39.6 12.1 Sonoma Mt. 42.9 48.9 36.7 12.3 Potter Valley 43.0 53.3 40.2 13.1 Redwood Valley 43.6 52.8 38.0 14.8 Bennett Valley 43.6 48.7 36.3 12.3 Napa Sonoma Co Green Valley 43.6 54.6 38.4 16.3 Petaluma Northern Sonoma 43.8 77.6 37.8 39.7 Mendocino 43.9 59.8 34.6 25.2 North Coast 44.0 78.1 21.0 57.2 Spring Mountain District 44.3 51.3 35.4 15.9 Covelo 44.4 53.4 43.1 10.3 Benmore Valley 44.6 45.6 43.7 1.9 Cole Ranch 49.5 50.2 48.8 1.4 Yorkville Highlands 50.1 62.9 40.9 21.9 Dry Creek Valley 50.1 71.0 40.7 30.2 Dos Rios 51.6 64.6 48.7 15.9 Mendocino Ridge 53.6 68.1 43.5 24.7 Rockpile 57.4 65.8 48.3 17.5 Annual Precipitation (inches)

AVA Name Median Max Min Range

High Valley 33.6 54.1 28.3 25.7

Clear Lake 33.9 65.4 25.0 40.4

Red Hills Lake County 39.9 64.1 25.9 38.2

Guenoc Valley 42.8 44.8 40.5 4.3

Benmore Valley 44.6 45.6 43.7 1.9 West Coast Climate Variability Climate Variability Mechanisms

. Most mechanisms are winter/spring dominant, but can influence vintages . Much interaction between regional and distant mechanisms via teleconnections . Impact studies are lacking in many regions

Jones et al. (2012: The Geography of Wine) Pacific Ocean/North America Climate Variability Mechanisms

. Cold water in . Warm water in central North central North Pacific supports Pacific supports a trough there a ridge there . Warm water . Cool water along along West West Coast Coast supports supports a trough ridge there there . PNW = warmer . PNW = colder and drier and wetter . California = . California = drier wetter and and moderately slightly warmer colder

Jones and Goodrich (Climate Research 2008) El Niño and warm PDO La Niña and cold PDO Current Situation and 2013 Vintage Forecast Current Sea Surface Temperatures

Current and Projected Pacific Ocean/North America Climate Variability Mechanisms

. Neutral ENSO projected through late summer 2013 . Negative phase of the PDO (cold coastal waters), projected to warm through late summer 2013 . These conditions historically bring a slightly cooler than normal spring and near normal precipitation for Oregon, Washington, and Idaho; but warm & dry in California . Summer is mixed, but tends to point to more normal temperatures and GDD Summary/Conclusions Lake County Wine Region . Approximately 200 growers with over 8500 acres planted to elevations 1500 ft or higher Lake County Wine Region . Mountain environment along the ‘axis of cab’ ... Lake County Wine Region . Landscape and climate conditions suitable for a wide range of varieties … Lake County Wine Region . Landscape and climate conditions suitable for a wide range of varieties … − 2800-3800 GDD − Median last spring frost early to mid April − Median first fall frost early November to early December − Median frost-free period 200-250 days − Annual precipitation 33-45 inches Lake County Wine Region . Landscape and climate conditions suitable for a wide range of varieties … − High UV radiation influences on ripening − High diurnal temperature ranges, retention of acidity − Truncation of season to cool nights during ripening − Moderation effects of Clear Lake − Both mountain-valley breezes and strong lake-land breezes enhance local moderation Spring/Summer 2013 Forecast Summary For the Western US in general:

. Tropical SST conditions have warmed . North Pacific SST conditions, warmer but still remain cooler than normal . Taken together these conditions tilt the odds in favor of a cool and moderately dry (south) to slightly wet (north) late spring to early summer for the Western US . Dynamic models and historical analogs point to normal heat accumulation during the second half of summer Thank You!

Gregory V. Jones Dept of Environmental Studies