Multi-State Forecast for Upcoming Frosts & Freezes & 30 Day Ag Weather Outlook VA – TN- NC – SC (11:30am, Thur, 4/7/16)

— Written By Barclay Poling revised-table

Fig. 1. Much of the crop in VA and MD is in critical bloom stage. An open blossom can handle temperatures down to 28, but not lower. Of course, if frost occurs, the critical temperature can be as high as 31 F. In the grower reports below, you will learn that even a single row cover was not enough for min air temp in canopy of 23.

7daytemp.se.6Fig. 2. Southeast Min Temp Map for Sunday morning. Purple 15-20, Teal 20-25, Light blue 25-30

Dear Agents, Agronomists, Growers and Others,

I have received some very interesting reports from growers in North Carolina, Virginia and Maryland since last night. So, in Part A, I share these experiences with you. In Part B you will find in-depth weather advisory information for each state I cover (MD, VA, NC, SC and GA). In Part C you will find the OUTLOOK that we regularly post on Sun/Mon — I am just posting this.

Part A. Grower reports from Wed morning frost event:

A.1. Maryland

** The grower wrote me:

“we had a lo of 23 here are some pics
covers alone would not have done it
we started watering at 2 a.m. with a lo of 26 and immediately made ice ,within 10 minutes temps under the covers went to 40”

blacksweetc - low resFig. 1. Low of 23 and no water, just row cover, was not enough

under cov 1 low resFig. 2. Under the cover with watering gave a good outcome

no cover dead lowFig. Except for blossoms in touch with cover! The grower wrote, “…any blossom that was in contact got a blackeye.”

A.2 North Carolina

** Durham –

Good Morning Barclay,
Just letting you know that Skybit was the winner. I looked at the AWIS but I have to use the unc chapel hill one, not raleigh durham. That one is more for Dannys side of town. To warm for me. I also looked at accuweather, and underground weather durham. Skybit said I would crank at 12 and off at 8. At 12 the field had ice on black plastic pipe and ice forming on leaves so I had everything running by 12:30. Shut her down at 8. Had more ice this time than I can remember having in a long time. All went well.
Lets hope for a successful sat night.
thanks,
mark

** Nash County – I asked a producer last evening how row cover protection worked out for Wed morning, and the response I got was that the single row cover did well.

The grower wrote:  “I think the covers handled it ok even tho we got to 28 weather station temp”

A.3 Virginia

** Hi Dr Poling
Saw your post about Lowell Yoder. I’m concerned about sat night and looking for extra covers. What is lowells cell number? I’d like to ask where he got some last minute. I usually order from atmore and it takes  awhile
Thanks

>> Reply – Lowell is listed in the NCSA Member Directory, and the cell number I found was 434-401-4864. Really glad it helped him through the other night to have the double cover. That should be effective into the very low 20s, and perhaps even give protection at 20 F.

Row cover suppliers: Row cover suppliers

Part B. In-depth weather advisory information for MD, VA, NC, SC and GA

Maryland:MD Min Temp

10-DAY DETAILED HOURLY WEATHER FORECASTS

Aberdeen Andrews_AFB Annapolis_Naval Baltimore_Sci_Ce
Baltimore/Wash Cambridge/Dorche College_Park_AP Cumberland_AP
Easton_MD Fort_Meade Frederick_MD Gaithersburg_AP
Hagerstown_AP Leonardtown Middle_River Oakland_MD_AP
Ocean_City_AP Patuxent_River Salisbury Stevensville_AP
St_Inigoes/Webst Washington_DC_AP Westminster_AP

Virginia:VA Min Temp

10-DAY DETAILED HOURLY WEATHER FORECASTS

Abingdon Ashland_VA Charlottesville Chesapeake-Ches
Culpeper Danville Dublin/New_Riv Emporia_VA
Farmville Fentress_Naval_A Fort_Belvoir/Da Fort_Eustis/Fel
Franklin/J_B_Ro Hillsville Hot_Springs/Ing Jonesville_AP
Langley_AFB Leesburg/Godfre Louisa-Louisa_C Lynchburg
Manassas_Muni(A Marion/Wythev Martinsville Mecklenburg/Bru
Melfa/Accomack Newport_News Norfolk_Hampton_ Norfolk_NAS
Norfolk_VA Oceana Orange_VA Petersburg_(AWO
Quantico Richlands_AP Richlands_VA Richmond
Richmond_Chester Roanoke Shannon_Arpt Stafford_AP_VA
Staunton-Shenan Suffolk-Suffolk Tappahannock_AP Virginia_Tech_A
Wakefield_AP Wallops_Island Warrenton_Fauqui Washington_Dulle
West_Point_VA Williamsburg_VA Winchester_Rgnl Wise/Lonesome_P

A SkyBit for location near Richmond:  it shows 24 F minimum on Sunday morning. One thing I am concerned about here is winds…you note the avg wind of 9 mph. That is the upper limit for sprinkling only. But, in examining an AWIS product for Farmville, VA (near this SkyBit location), I see that the turn on time for sprinkling is very early in the evening when air temp is 43, the wet bulb down to 33 F! And, at this time winds are raging. This is where I would suggest a row cover! Sprinkling and row cover can handle this, but you really need both.

20160407st1.VACHLfarmvilleFarmville – AWIS hourly. Farmville  The winds will make sprinkling alone very difficult – the wet bulb will be 33 at 5 p.m. (grower will need to start then when winds are still raging at 20 mph). The grower really needs to get a row cover before this freeze! The winds are too much to manage with sprinkling alone. The other option is two row covers. I believe two covers of 1.25 oz could handle 22, but not sure about 20. SkyBit says it will only hit 24 F.

North Carolina

7daytemp.nc.6

Minimum Temps for Multiple Locations in NC: NC Min Temp

10-DAY DETAILED HOURLY WEATHER FORECASTS

Ahoskie-Tri-Cou Albemarle_AP Andrews Asheboro
Asheville_Munic Beaufort-Michae Boone_NC Burlington-Burl
Cape_Hatteras_AG Chapel_Hill-Hor Charlotte Cherry_Point
Clinton_NC Concord_NC Currituck_NC Edenton-Northea
Elizabeth_City Elizabethtown_NC Erwin-Harnett_C Fayetteville_AP
Fort_Bragg/Simm Franklin/Macon_C Gastonia-Gaston Goldsboro_AFB
Goldsboro_NC Greensboro Greenville_AP_NC Hickory
Jacksonville Jacksonville_(A Jefferson_AP_NC Kenansville-Dup
Kill_Devil_Hills Kinston_AP Lexington-David Lincolnton_AP
Louisburg_NC Lumberton_AP_NC Mackall_AAF Manteo/Dare_Co
Maxton Mcalf_Bogue_Fiel Monroe_AP_NC Morganton-Morga
Mount_Airy-Moun New_Bern North_Wilkesbor Oxford_NC
Piney_Island_Bom Pope_AFB Raleigh-Durham Reidsville_AP
Roanoke_Rap_AP Roanoke_Rapids_R Rockingham_NC Rocky_Mount-Wils
Roxboro_AP Rutherfordton Salisbury-Rowan Sanford_NC
Shelby_AP_NC Smithfield_AP Southern_Pines Southport_NC
Statesville-Sta Tarboro_AP Wadesboro_AP Washington-Warr
Whiteville_NC Wilmington_AP_NC Winston-Salem

Agent Question in NC

Dr. Poling,

I hope retirement is going well! It seems your just about as busy as you used to be! I had a grower question today that is complicated and I thought I’d run it by you.
Saturday night is supposed to be in the mid 20’s at this growers location. There is the possibility of pretty good wind (35 mph during the day, night wind speeds unknown). Like most others, we have green fruit and multiple open flowers.
His question was, should he:
1. use covers (heavy cover) and water overhead (igloo effect)
2. try to overhead frost protect only
3. use covers only
We’d like your opinion if we can get it! Most of the time when we get this cold, we don’t have as much green fruit and bloom as we do now. Thanks!
REPLY:
1. I don’t recommend  “trying anything” with sprinkler irrigation only in these winds and with temps in mid-20s. Sprinkling with these winds can be  devastating, and not only kill reproductive plant parts, but do damage to plant itelf!
2. Row Covers are much better choice. The heavier the weight, the better, and double covers would be an ideal solution (med weight covers in 1 to 1.25 oz range)
3. If he cannot do double cover, then I would consider getting ready to sprinkling on the row covers. We already know from an experience in MD that a low of 23 and row cover only, doesn’t work! I would work with this gentleman to see if he cannot quickly locate a second row cover NOW. If that is not practical to do, then he needs to make sure he understands that once you commit to sprinkling, you have to keep those nozzles turning, and he is going to have to have a crew working with him to beat ice off nozzles to make this work. Sometimes, you need to go through the field every 30 minutes to beat ice off nozzles. If you have a digital thermometer and thermocouple, you can work with him to monitor blossom temps closely. Be sure to get water running before the blossom temp under cover reaches 31 F. Do not wait any longer to start irrigation on cover.
My SkyBit for Clayton:
20160407st1.NCCLY

SC

Minimum temps for multiple locations in SC:SC Min Temp

10-DAY DETAILED HOURLY WEATHER FORECASTS

Aiken_AP Anderson_Co_Air Barnwell_AP Beaufort_Cnty_AP
Beaufort_SC Bennettsville_Je Camden_AP Charleston_Exec_
Charleston_Muni Cheraw_AP Chester_AP Clemson-Clemson
Columbia-Columb Columbia/McEnti Columbia_Metro Conway_AP
Darlington Florence_SC Georgetown_AP_SC Greenville_Donal
Greenville_Down Greenville-Spart Greenwood-Green Hartsville_AP
Hilton_Head_AP Kingstree_AP Lancaster-McWhir Laurens_AP
Manning_AP Marion_AP_SC Moncks_Corner_AP Mount_Pleasant_A
Myrtle_Beach Newberry_AP North_Myrtle_Be Orangeburg-Oran
Pickens_AP Rock_Hill Spartanburg_Down Summerville_AP
Sumter_AP Sumter_SC Walterboro_AP Winnsboro_AP

GA
7daytemp.ga.6

10-DAY DETAILED HOURLY WEATHER FORECASTS

Albany_Municipa Alma/Bacon_Co Americus_AP Athens_Municipa
Atlanta/DeKalb Atlanta/Fulton Atlanta_Intl_Ar Atlanta_Paulding
Augusta/Bush_Fi Augusta_Daniel_F Bainbridge_GA Blakely_AP
Brunswick_GA Brunswick/Glync Canton_GA Carrollton_AP
Cartersville_AP Claxton_AP Columbus_GA Covington_GA_AP
Dalton-Dalton_M Douglas_Muni Dublin/WHBarron Fitzgerald_AP
Fort_Benning Ft_Stewart/Wrig Gainesville_AP_G Greensboro_GA
Homerville_AP Hunter_(AAF) Jesup_AP La_Grange
Lakeland Lawrenceville_AP Macon_AP Marietta
Marietta/Cobb Milledgeville_AP Moultrie_Muni_AP Newnan-Newnan_C
Peachtree_City Rome_GA Savannah Statesboro_GA
Swainsboro_AP Sylvania_AP_GA Thomaston_AP Thomasville_AP
Thomson_GA Tifton_AP Valdosta Valdosta/Moody
Vidalia Warner_Robins_A Washington_GA Washington_GA
Waycross_AP Winder_AP

Part C. 30 Day Ag Weather Outlook VA – TN- NC – SC   (tough month ahead in April)

You will see swings from well below normal to near to even slightly above normal for first half of the month, which  is a challenge for the growers to manage. The second half of the month will likely average a bit above normal. We are now also seeing signs in the deterministic model ensemble runs that we will still see significant swings from cooler to warmer than normal the second half of April. Because of the variability we still have to be cautious on the exact timing and intensity of individual  weather systems and their impact on temperature, so we  advise growers  to pay close attention to the forecasts right through April.

image001

Forecast discussion day 3 – 5 (06 Apr – 08 Apr) Temperatures start below normal then rise slightly before falling again to well below  normal; wet mid period. Expect temperatures to start the period below normal, but expect temperatures to rise a bit by mid period under the influence of the southerly flow ahead of a low pressure system expected to move northeast up Mississippi River Valley into Great Lakes regions during this period. Strong cold front moving through the region causing periods of showers and thunderstorms by later in the period that is associated with the low pressure system. Once cold front moves through the region, late in the period temperatures will plunge to well below normal. Early in the period, expect highs to range from mid 40s to mid 60s and lows in low 20s to low 40s. Mid period, expect highs to range from mid 60s to mid 70s and lows in upper 30 to mid 40ss. Late in period, expect highs to range from the upper 40s to near 60 and lows in upper 20s to mid-40s. Precipitation amounts expected to be in 0.35” – 0.50”range.

image002

Forecast discussion day 6 – 8: (09 Apr – 11 Apr) Temperatures start out well below normal, then rise to slightly above normal by late in period; mostly dry during this  period.   A cold high pressure from Canada will push cold arctic air into the region early in the period keeping temperatures well below normal. Expect the high pressure to quickly move east so that by mid period the regions will be under southwesterly flow on the west side of the departing high pressure system and the east side of a slowly approaching low pressure system and cold front. The southwesterly flow will increase late in the period warming temperatures to near or slightly above normal. Expect little if any precipitation during this period. Early in the period, expect highs to range from mid 40s to low-60s and lows in the low 20s to mid 30s. By late in the period, expect highs to range from upper 50s to low-70s and lows in the upper 30s to mid 40s. Precipitation amounts expected to be in the 0.00” – 0.05”range.

image003

Forecast discussion day 9 – 11: (12 Apr –14 Apr) Temperatures start out slightly above normal but fall to below normal by late in period; widespread showers and thunderstorms early in period.   Expect another strong cold front to move from west to east through the region and off the coast by mid period. This will bring a period of showers, thunderstorms and a significant cool down in temperatures by mid period. Stay on the cold side of normal through the remainder of the period. Early in the period, expect highs to range from upper 50s to low-70s and lows in upper 30s to mid 40s. By late in the period, expect highs to range from upper 40s to low-60s and lows in upper 20s to upper 30s. Precipitation amounts expected to be in the 0.15” – 0.40”range.

image04

Forecast discussion day 12 – 14:  (15 Apr – 17 Apr) Temperatures start below normal then rise to near normal; wet late in the period. Expect a cold high pressure system to slowly moderate and move east of the regions from west to east. This will allow temperatures to start the period below normal then slowly rise to near normal. By late in the period expect a low pressure system is expected to develop in the southeastern US and move northeast into the region bringing a threat of widespread steady rain. Early in the period, expect highs to range from mid 40s to low 60s and lows in low 30s to low 40s. Mid to late-period, expect highs to range from mid 60s to mid 70s and lows in upper 40s to near 50. Precipitation amounts expected to be in 0.15” – 0.30”range.

Day 15 – 30 Temperature and Precipitation Outlook 18 Apr – 3 May

image005image006

Outlook discussion day 15 – 22(18 April– 25 Apr) Temperatures near normal with near average precipitation. Early indications are temperatures will be near seasonal average with near to slightly above normal precipitation this period. However, still expect significant swings in temperature.

Outlook discussion day 23 – 30:  (26 April– 3 May) Temperatures slightly above normal with below average precipitation. Early indications are temperatures will be slightly above seasonal average with below normal precipitation this period.