Major Weather Changes Over Next 48 Hours. Winter Storm To Bring Rain And Snow To Forecast Area.

Good Afternoon Foothills Weather Followers.  The weather over the next 48 hours will change. At noontime today temps are spread everywhere from the upper 40’s to around 60°. Old Fort is at 58°, Marion 55°, Lake James 57°, Morganton 54°, Gamewell 54°, Lenoir 53°, Kings Creek 52°, Granite Falls 52°, Valdese 58°, Lake Lure 50°, Rutherfordton 49°, Ellenboro 48°, Mooresboro 51°, Shelby 50°, Earl 56°, Grover 56°, Kings Mountain 52°, Lincolnton 54°, Iron Station 48°, Shoups Ford 48°, Newton 54°, Hickory 52°, Bethlehem 55°, and Taylorsville 52°. 

 

Clouds rapidly increasing ahead of low pressure that will approach the area Sunday.  Let’s get right to the forecast. It is slowly coming into better view. Here is our current weather map and where our systems currently are:

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Going through the pieces to this forecast puzzle. Number 1 is the upper level low pressure over Wyoming and South Dakota. Puzzle piece 2 is in Texas Panhandle. Piece 3 is high pressure over Canada pushing cold air down the eastern slope of The Blue Ridge. Piece number 4 will be a low pressure that develops somewhere over Coastal South Caro,ina and moves North. The coastal low will move North and quickly deepen into the third nor’easter in as many weeks. Keys to putting this puzzle together are nailing down the track of the Texas low, evolution and timing of the upper level low, how long high pressure in Canada hangs on before weakening, and how quickly the coastal low forms and weakens, and if the upper level low can phase with the coastal energy.

Let’s first look at several clips of the Noontime GFS Model run: 

 GFS Noontime Run. Timing is where it reads valid at 18z (Zulu Time so subtract 4 hours from 18z which is 2:00pm)

Now let’s take a look at the NAM’s Noontime run. Again as above times are in Zulu time so subtract four hours off the valid time. 

You can see that overnight the NAM has come into better agreement with the GFS/Euro. 

 

So, lets put this all together. We will take a blend of the GFS/EURO/NAM. Rain will develop this evening could receive as much as an inch and a half of rainfall. Below is the model estimated rainfall totals through Monday. Some places down near the South Caro,i a boarder could receive as much as 2 inches of rain. I wouldn’t even rule out some thunder right along the boarder and South into South Carolina.  I will highlight the mountains precipitation totals too but most of that will fall as snow up there.

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Looking over atmospheric temperatures those will support all rain initially even in the mountains. As the Texas low starts to transition it’s energy to that coastal low, cold air will wrap into the area. The high pressure over Canada just looks too weak to be able to supply enough cold air this far south to support anything but rain. However once cyclogenises occurs along the coast and that low pulls in more cold air Sunday Afternoon rain will change to snow above 3000ft. The snow will be heavy at times up in the mountains. Rain continues Sunday afternoon in the foothills. To get the foothills changeover to snow it’s going to take that upper level low getting in and phasing its energy with the coastal system. Another important note is the wind. Winds will increase NE 10-20mph with gusts to 25mph in the foothills and 20-30mph in the mountains with gusts to 40mph. Temps in the mountains fall Sunday evening to below freezing and into the upper 20’s. This will be a heavy wet snow. It will stick to power lines and trees. Couple that with the winds in the mountains, power outages could start up there quickly Sunday Night. As the upper level low begins to phase with the coastal low Monday Morning snow levels will fall to around 700 - 1000ft, basically along and North Of I-40. Temperatures in the foothills along and North Of I-40 will fall into the mid 30’s by Monday’s sunrise.  South of 40 temps will drop into the upper 30’s to around 40°. The Hwy 74 corridor and North will likely see snow mix in with the rain Monday Morming. South Hwy 74it will be mostly rain.  Precipation will come to an end on Monday. There is some question as to what time though. GFS is likely handling this aspect better with ending precipitation around 1pm from West to East but will note that the NAM wants to hold onto it about two hours longer

 

So let’s summarize this. First here is our accumulation forecast:

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Mountains:  (Red Area)

Rain starts Saturday Night. Transition to snow should begin late morning into early afternoon Sunday. Snow will fall heavy at times. Heavy wet snow and winds gusting to 40mph could fail trees and power lines. Temps fall into the upper 20’s by Sunday Afternoon. Winter Storm Watch looks well placed up there. View it here.... Snow continues through Monday Evening. Total snow accumulation of 5-8 inches with locally higher amounts.

Eastern Escarpment: (Blue Area) 

Rain starts tonight. Rain will mix with and change to snow by Sunday Afternoon. Snow could be heavy at times. Snow continues through Monday Evening. This will be a heavy wet snow and winds could gust to 40mph. 2-4 inches of snow accumulation with locally higher amounts above 3000ft. Low temps around 30°.

Northern Foothills: (White Area) 

Rain begins tonight. Rain continues into Sunday Night. Sunday Night rain should mix with and change to snow by sunrise Monday.  Snow likely continues through the morning hours Monday.  If precipitation holds on long enough Monday it may mix with rain. Total snow accumulations of a trace to 2 inches. Lowest temps in the mid 30’s so roads should remain mostly wet. Winds gusting to 30mph could cause isolated power outages.

Southern Foothills: (Green Area) 

Rain begins tonight and will be heavy at times. Localized urban flooding is possible Sunday as rain continues. Rain continues into Monday Morning and likely will mix with snow during the heaviest bursts of precipitation.  Winds gusting to 25mph May cause localized power outages. Lowest temps in the upper 30’s.

 

Southern Foothills: (Yellow Area) 

Mostly rain event. Rain will be heavy at time and localized low lying areas may see minor flooding by Sunday Afternoon. A brief mix of rain/snow possible Monday Morning. No accumulation. lowest temps in the low 40’s. 

 

Christopher White

Chief Meteorologist

Foothills Weather Network