Multi-State Forecast for Upcoming Frosts & Freezes & 30 Day Ag Weather Outlook VA – TN- NC – SC (11:30am, Thur, 4/7/16)
go.ncsu.edu/readext?406297
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.
Fig. 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”
Fig. 1. Low of 23 and no water, just row cover, was not enough
Fig. 2. Under the cover with watering gave a good outcome
Fig. 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
Virginia:VA Min Temp
10-DAY DETAILED HOURLY WEATHER FORECASTS
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.
Farmville – 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
Minimum Temps for Multiple Locations in NC: NC Min Temp
10-DAY DETAILED HOURLY WEATHER FORECASTS
Agent Question in NC
Dr. Poling,
SC
Minimum temps for multiple locations in SC:SC Min Temp
10-DAY DETAILED HOURLY WEATHER FORECASTS
10-DAY DETAILED HOURLY WEATHER FORECASTS
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.
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.
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.
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.
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
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.