By the Numbers: Detailed Forecast Information From AWIS for Mult-State Region (11:38am Am Mon April 14, 2014)

— Written By Barclay Poling

Multi-state update on cold weather coming!

1. NC – see earlier update this morning at 9:30 a.m.

  • In case you missed it, here is the minimum temp info for NC: AWIS Apr 14 to 21
  • Also, here are the detailed forecasts

5-DAY DETAILED HOURLY WEATHER FORECASTS 

2. SC- Here is the minimum temp forecast for SC: SC AWIS Apr 14 to 21

Grower question from SC:

Just got this note from Eric Hunter:

There is now a very strong likelihood that we will dip into the upper 20s tomorrow night WITH winds. Skybit is calling for 32 canopy at my home farm, which means 28ish at our other land. We are going to get ahead of the rain and wind and put out row covers down there as the irrigation isn’t quite as capable as it is here at our home. We have already removed row covers from the field here and are going to wait until tomorrow before deciding on using them on these fields. Our irrigation is pretty strong here at the home land and I have protected into the upper 20s with mid teen winds in the past. The winds are projected to be gusting as high as 20 during the night, but I really expect them to die down.

You mentioned seeing a frost under the row covers in the past in times of high humidity I believe. Could you elaborate on that if you have time?
Thanks,
Eric

Repy- Eric is in the foothill region of SC, and he is anticipating a minimum of  28 F at his coldest farm (from his SkyBit), I can see why he may wish to “cover up” now (Monday) in advance of rains to be on the safe side, in case it does drop to 28 F in the strawberry canopy, or possibly go lower?? The AccuW forecast is only for 39 F low in Easley on Wed morning. So, that’s quite a difference between AccuW and Skybit in canopy (maybe 28 at colder farm). I just checked wind forecast to see if row covers could possibly cause flapping injury, as the crop is very tender right now. With ave winds in 13 mph I see no problem with winds. Eric has decided to go with a play safe approach at his colder farm. The rains are coming in Tue, so he has covered today. He has a sprinkler system at the home farm (warmer location), and will check forecast tomorrow before making a final decision on what to do there.

Easley, SC Forecast

Table 1. Winds will not likely cause  ‘flapping injury’ to the crop unless they get into 20s and 30s (mph).

I like the irrigation option at this time of year for obvious reasons. With row covers you must make decisions in advance of the cold event, like having to apply them today b/c of rains on Tuesday, and with irrigation you can play it by ear until we get closer to the actual event. Unfortunately, I have seen forecasts change significantly this season from 48 hrs ahead to 24 hrs ahead. Thus, you cannot be very ‘interactive’ with row cover technology as you can with sprinkling. With sprinkling we are concerned with winds and lower dewpoints, and have a rule of turning on at wet bulb of 31 F, but I see the wet bulbs are pretty high Tue night/Wed morning, and actually stay above 31 the whole night, so this gives us a break as far as having to turn on real early in the night, as we did on a black frost event in late March. To the point of Eric’s question – he is concerned about a frost under the row cover happening. I don’t see this occurring, as winds will be relatively high through the night and dewpoints are in low 20s. You need very humid, saturated, still conditions to see an actual frost under the cover – which I have seen occur. But, this is not one of those nights. Easley SC ForecastTable 2. The dewpoints are in low 20s, and no real chance for frost under cover unless dewpoints are up in very high 20s and low 30s

SC Detailed Forecasts: 5-DAY DETAILED HOURLY WEATHER FORECASTS 

Anderson_Co_Air Beaufort_SC Charleston_Muni Clemson-Clemson
Columbia-Columb Columbia/McEnti Columbia_Metro Darlington
Florence_SC Greenville_Down Greenville-Spart Greenwood-Green
Hilton_Head_AP Myrtle_Beach North_Myrtle_Be Orangeburg-Oran
Rock_Hill Sumter_SC

 3. Virginia3a. Minimum temperatures for next 7 days: VA AWIS Apr 14 to 21

3b. Minimum temperature maps for Wed and Thur morning

Minimum temperature forecast map, VirginiaFig. 1VA Min temp Wed

Minimum temperature forecast map, VirginiaFig. 2. VA min temp on Thursday – note deeper penetration of light blue area on this second night (25-30).

Here you can see that the 2nd night in the Central VA town of Ashland is definitely the more risky one at this stage (Table 3).

Forecast data for AshlandTable 3. FROST is in forecast for Ashland the 2nd night. A minimum temperature of 30 with winds does not pose a problem (the first night). If winds die down on Wed morning, which I do not believe they will, then there is a possible frost scenario. But, my bet is that the frost will occur the next morning (Thur). This cold event can be managed with either sprinkling or row covers. If a grower in this area felt it could frost on Wed morning, then the covers would need to go on Tuesday afternoon at the latest. If rains are going to come in Tue., then the covers would have to go back on today.

3c. Here are the detailed VA 5-day forecasts from AWIS – these let you check to see if FROST is expected:

5-DAY DETAILED HOURLY WEATHER FORECASTS 

4. MD

4a. MD AWIS Apr 14 to 21

4b. Freeze map for Wed; and Min Temp Map for THUR and FRI

Maryland Freeze forecast map Maryland Freeze forecast map

Maryland Freeze forecast mapFig. 5 What I am stuck by is how cold it will be in MD on FRIDAY as well.

Here is how this may play out in eastern MD in Salisbury

4c. Detailed AWIS forecasts for these MD locations

5-DAY DETAILED HOURLY WEATHER FORECASTS 

5. TN min temps for state: TN AWIS Apr 14 to 21

Detailed information for these TN locations

5-DAY DETAILED HOURLY WEATHER FORECASTS 

6. KY min temps for state:

Western KY Frost Freeze forecast:KY AWIS Apr 14 to 21

AWIS Weather Services, Inc. Western Kentucky Frost/Freeze Forecast
Produced at  504 a.m. CDT on Mon Apr 14 2014

... Forecast for Tonight ... Southwest Kentucky                      
NWS Fcst Zones 1-13                               

**** NEAR FREEZING COLD LOCATIONS  ****
**** LITTLE IF ANY FROST DUE TO CLOUDS/WIND **** 

Lowest Temperatures:      34 - 39
Murray Min                  39 
Range Dewpoint Temps:     31 - 55
Range Wetbulb  Temps:     33 - 55
AVG Wind Direction/Speed:  NW 15                          
AVG Sky Condition:         Cloudy   

Extended Forecast: Range of Lowest Min Temperatures in the Above Zones
Min Temps Valid For Morning of Given Date (May NOT include ALL cold pockets)

  04/16/14  04/17/14  04/18/14  04/19/14  04/20/14  04/21/14
  --------  --------  --------  --------  --------  --------
   30 - 32   38 - 40   49 - 51   42 - 48   43 - 46   45 - 48
--------

Grayson County Area                     
NWS Fcst Zones 23-24,26-28,61-63                  

**** NEAR FREEZING COLD LOCATIONS  ****
**** LITTLE IF ANY FROST DUE TO CLOUDS/WIND **** 

Lowest Temperatures:      34 - 37
Leitchfield Min             36 
Range Dewpoint Temps:     34 - 52
Range Wetbulb  Temps:     35 - 54
AVG Wind Direction/Speed:  NW 14                          
AVG Sky Condition:         Cloudy   

Extended Forecast: Range of Lowest Min Temperatures in the Above Zones
Min Temps Valid For Morning of Given Date (May NOT include ALL cold pockets)

  04/16/14  04/17/14  04/18/14  04/19/14  04/20/14  04/21/14
  --------  --------  --------  --------  --------  --------
   25 - 30   35 - 38   43 - 48   43 - 47   41 - 44   43 - 46
--------

For more detailed information visit www.awis.com or call 888-798-9955. Copyright 2014 AWIS Weather Services, Inc. All rights reserved.

Detailed KY forecasts:

5-DAY DETAILED HOURLY WEATHER FORECASTS 

Good luck!

Barclay

Dr. E. Barclay Poling
Interim Executive Director, NC Strawberry Association Inc.
& Professor Emeritus (Strawberry Plasticulture Researcher)
Department of Horticultural Science
Campus Box 7609, 162A Kilgore Hall
NC State University
Raleigh, NC 27695-7609
A pessimist sees the difficulty in every opportunity, an optimist sees
the opportunity in every difficulty.
Winston Churchill, Prime Minister of England