30 Day Ag Weather Outlook MD – VA – TN- NC – SC (2:45pm, Sunday, April 2, 2017)

— Written By Barclay Poling

Weekly General Weather  Discussion

As expected, the snow depth charts are now showing a significant  reduction in snow cover in the Canadian Great Plains provinces of Manitoba, Saskatchewan, and Alberta. However, the snow cover is only slowly melting in the Northeast US and Eastern Canada and has actually increased in recent days in the northeast region due to some late season snowstorms.

The overall reduction in snowpack  is allowing warmer temperatures to develop in the middle part of the country and as expected has moved east into the forecast region causing  temperatures generally to rise to  near or somewhat above normal for the past few days. This warming trend will very likely  extend into the first few days of April. But the mentioned snow cover in the Northeast US and Canada provides the risk of an unexpected surge of cold air into the eastern third of the US if  a  low pressure system were to develop in the eastern US-Canada region. The  wind circulation around a low pressure system in this location could tap into the cold air and cause a cold snap and bring the threat of late season frost to the MD – VA – TN- NC – SC.

It now appears there is  potential for at least two such cold snap events  occurring over the next month. The first cold event looks to be shaping up for later this week (note this morning’s advisory re: possible frost next Saturday), and then again  around April 15th. However on the average it still looks like the temperatures will be above normal and precipitation near normal for the period April to May.

Forecast discussion day 3 – 5  (05 Apr – 07 Apr) Temperatures start above normal end below normal; scattered rain showers mid to late in the period. High pressure system will slowly move east of the region as a low pressure system forms in the mid-Mississippi River Valley and moves northeast with the center of the system passing just north and west of forecast region. This will allow for above average seasonal temperatures by 4-8 F through mid-period with scattered rain showers mid to late in the period. Expect a cooling trend after the low moves north and east of the region into Canada. So expect temperatures to be below normal by 2-4 F by late in the period. This will allow for the possibility of scattered frost in the northern sections of the forecast region if overnight skies become clear. Early to mid-period, expect high temperatures to range from the low 60s in the far north to upper 70s in the south. Low temperatures ranging from the low 40s to low 50s. Late in the period, expect high temperatures to range from the low 40s in the far north to low 60s in the south. Low temperatures ranging from the low 30s to low 40s. Precipitation amounts will likely be in the 0.05 – 0.15” range.

Climatology:   

Station High T Low T   Station High T Low T
Charlottesville VA 64 43 Greensboro NC 66 42
Richmond VA 64 41 Asheville, NC 64 40
Roanoke VA 62 42 Charlotte, NC 67 42
Hillsville VA 59 34 Fayetteville, NC 66 43
Salisbury, MD 62 41 Aberdeen, MD 62 40

Forecast discussion day 6 – 8:  (08 Apr – 10 Apr) Temperatures below normal early warm to above normal late in the period; scattered showers north early in the period. Expect the previously mentioned low pressure system to move east-northeast into the Canadian maritime and weaken. This will help keep a cold northwest flow across the forecast region early in the period. But as the low weakens a warmer southwest flow will likely develop across the forecast region late in the period. Expect the period to be mostly dry with only scattered rain showers in the extreme northern sections of the forecast region early in the period. Early in the period, expect high temperatures to range from the low 40s in the far north to low 60s in the south. Low temperatures ranging from the low 30s to low 40s. By late in the-period, expect high temperatures to range from the low 60s in the far north to mid 70s in the south. Low temperatures ranging from the upper 40s to low 50s. Precipitation amounts will likely be in the 0.05 – 0.15” range.

Climatology:

Station High T Low T   Station High T Low T
Charlottesville VA 66 44 Greensboro NC 67 44
Richmond VA 66 43 Asheville, NC 64 42
Roanoke VA 64 43 Charlotte, NC 68 44
Hillsville VA 60 35 Fayetteville, NC 69 44
Salisbury, MD 62 42 Aberdeen, MD 64 42

Forecast discussion day 9 – 11:  (11 Apr – 13 Apr) Temperatures above normal; widespread rain showers/thunderstorms western sections of the region late in the period. A low pressure system and accompanying cold front will approach the region slowly from the west. Ahead of the front the winds will be from the southwest bringing above normal temperatures to the region. By late in the period, the front will likely be close enough for showers and thunderstorms to form in the western sections of the region. Expect high temperatures to range from the upper 60s in the far north to upper70s in the south. Low temperatures ranging from the upper 40s to low 50s. Precipitation amounts will likely be in the 0.25 – 0.50” range in western section of the region with little precipitation at other locations.

Climatology:   

Station High T Low T   Station High T Low T
Charlottesville VA 67 45 Greensboro NC 69 46
Richmond VA 68 44 Asheville, NC 65 43
Roanoke VA 66 43 Charlotte, NC 70 45
Hillsville VA 63 37 Fayetteville, NC 71 45
Salisbury, MD 65 43 Aberdeen, MD 65 43

Forecast discussion day 12 – 14:   (14 Apr – 16 Apr) Temperatures start above normal then fall below normal by late in the period; widespread showers with scattered thunderstorm though the period. Expect a strong cold front to move slowly through the region over the course of the three day period. The front will likely bring widespread shower and scattered thunderstorm activity to the forecast region for the entire period. The temperatures will start the period above normal but then fall below normal as the front passes to the east of a given location. Expect the air behind the front will be cold enough to support scattered frost at locations where the skies clear overnight. Expect high temperatures to range from the low 40s to low 50s. Low temperatures ranging from the upper 20s to low 30s. Precipitation amounts will likely in the 0.50 – 0.80” range.

Climatology:   

Station High T Low T   Station High T Low T
Charlottesville VA 69 46 Greensboro NC 70 47
Richmond VA 70 46 Asheville, NC 67 45
Roanoke VA 68 45 Charlotte, NC 72 47
Hillsville VA 64 38 Fayetteville, NC 73 47
Salisbury, MD 66 44 Aberdeen, MD 66 45

Day 15 – 30 Temperature Outlook 17 Apr – 02 May

Day 15 – 30 Precipitation Outlook 17 Apr – 02 May

Outlook discussion day 15 – 22:     (17 Apr – 24 Apr) Early indications are that temperatures will be below the seasonal average and precipitation above the average during this period. Outlook discussion day 23 – 30:  (25 Apr – 02 May) Early indications are that temperatures and precipitation will also be above the seasonal average during this period.
General Seasonal Outlook Mar – May 2017
Expect the forecast region to be generally warmer and wetter than normal for the period Mar – May 2017. The storm track and position of the semi-permanent Atlantic high pressure system will promote warm and moist southerly flow from the Southeastern states into the Mid-Atlantic states during the period. With abundant moisture and expected precipitation, expect that there will be a tendency for the minimum temperatures to be well above normal and the high temperature averaging only slightly above normal.

Items of Interest
The April 2 snow cover chart shows more extensive and deeper than normal snow cover for this time of year in eastern Canada and the northeastern US. This will allow air to remain colder than normal in the northeast and act as a source region for cold snaps in the middle Atlantic sections of the US if a pressure pattern forms that brings a broad northerly flow in to the eastern half of the US.