127
FXUS62 KCAE 170729
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
229 AM EST MON FEB 17 2025
SYNOPSIS
COLD, DRY AIR WILL FILTER INTO THE REGION BEHIND THE DEPARTING
COLD FRONT TODAY. A QUITE COOL AND DRY AIR MASS WILL SETTLE
OVER THE AREA THROUGH TUESDAY AHEAD OF A DEVELOPING LOW PRESSURE
SYSTEM TO OUR WEST. SOME WINTRY PRECIP IS POSSIBLE ACROSS THE
NORTHERN MIDLANDS AS A RESULT LATE WEDNESDAY WITH WIDESPREAD
RAIN EXPECTED. VERY COLD AND AIR FILLS BACK IN BEHIND THIS
SYSTEM FOR THE REST OF THE WEEK.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGE(S):
- WINDS CONTINUE TO DIMINISH
- TEMPERATURES FALLING BACK BELOW NORMAL.
EARLY THIS MORNING: COLD ADVECTION CONTINUES BEHIND THE COLD
FRONT, ALTHOUGH IT IS SLIGHTLY SLOWED BY WEST/NORTHWESTERLY
DOWNSLOPE FLOW. SKIES REMAINING CLEAR. WINDS WILL STILL REMAIN
UP THROUGH THE EARLY MORNING, HOWEVER THE GUSTS WILL BEGIN TO
DIMINISH THROUGH SUNRISE. TEMPERATURES FALL INTO THE LOWER 30S
BY DAYBREAK.
TODAY AND TONIGHT: THE PRESSURE GRADIENT WILL CONTINUE TO WEAKEN
THROUGH THE DAY, WITH SUSTAINED WINDS DROPPING BELOW 10 KNOTS
WITH LIMITED WIND GUSTS EXPECTED. LIGHT AND VARIABLE WINDS THEN
EXPECTED AFTER SUNSET. NORTHWESTERLY DOWNSLOPE FLOW WILL
CONTINUE THROUGH THE DAY, BUT THE COLD ADVECTION WILL STILL BE
STRONGER. HIGHS ONLY EXPECTED TO BE IN THE UPPER 40S TO THE
LOWER 50S, WHICH RETURNS THE REGION TO BELOW NORMAL. OVERNIGHT
LOWS WILL MOSTLY BE AROUND 30 UNDER GOOD RADIATIONAL COOLING.
SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/
KEY MESSAGE(S):
- COOL AND DRY WITH BELOW AVERAGE TEMPS.
MUCH THE SAME FOR TUESDAY AS FLOW ALOFT TURNS MORE ZONAL FROM
850-250MB OVER THE AREA. COLD ADVECTION WILL WEAKEN, AND WARM
ADVECTION WILL ACTUALLY DEVELOP ALOFT, BUT AGAIN TEMPS WILL
REMAIN A BIT BELOW AVERAGE. CLOUD COVER WILL INCREASE AS WEAK
WARM ADVECTION ALOFT WILL OVERSPREAD THE AREA BY LATE AFTERNOON.
LONG TERM /WEDNESDAY THROUGH SUNDAY/
KEY MESSAGE(S):
- WINTRY PRECIP ACROSS THE NORTHERN MIDLANDS POSSIBLE WEDNESDAY.
- COLD AIR FILLS FOR THE REMAINDER OF THE WEEK.
A SHORT WAVE WILL BREAK OFF THE PACIFIC JET AND DIVE
SOUTHEASTWARD INTO THE SOUTHERN US BY WEDNESDAY MORNING.
ASSOCIATED LOW PRESSURE WILL DEVELOP ACROSS THE DEEP SOUTH AND
PUSH EASTWARD INTO THE FORECAST AREA BY MIDDAY. AHEAD OF THE LOW
PRESSURE, WEAK HIGH PRESSURE AND SOME COLD-DRY LOW LEVEL AIR
WILL BE IN PLACE BUT THIS IS FAR FROM A CLASSIC WEDGE SETUP
LIKE WE USUALLY SEE BEFORE ICE EVENTS; THE EXTREMELY STRONG
SURFACE HIGH IS CENTERED FAR FROM A CLASSIC POSITION, BACK
ACROSS THE DAKOTAS. SO THE LOW LEVEL FLOW WILL GENERALLY KEEP A
NORTHWESTERLY COMPONENT AND NOT THE SELF-REINFORCING
NORTHEASTERLY INHERENT TO A TRUE CAD EVENT. CONSEQUENTLY, THE
SETUP FOR SOME POSSIBLE WINTRY PRECIP IS A BIT ATYPICAL WITH THE
APPROACHING LOW ITSELF CAUSING ENOUGH PRESSURE FALLS TO VEER
WINDS MORE NORTHEASTERLY AND THEREFORE STRENGTHEN LOW LEVEL
ADVECTION, AND THEN PROVIDE SUFFICIENT WARM ADVECTION ALOFT TO
DEVELOP SOME IN-SITU WEDGING. GUIDANCE IS A MIXED BAG ON THE
FREEZING RAIN POTENTIAL FOR WEDNESDAY GIVEN THE HIGHLY SENSITIVE
SETUP; EC AND CANADIAN ENSEMBLES HAVE TENDED TO BE THE COLDER
SOLUTIONS, WITH THE REST OF GUIDANCE WARMER WITH ANY FROZEN
PRECIP BACK ACROSS NC. OVERALL, THERE IS A CHANCE OF A BRIEF
PERIOD OF RAIN- SNOW MIX EARLY WEDNESDAY ON THE FRONT OF THE
SYSTEM AND THEN SOME FREEZING RAIN ACROSS THE NORTHERN MIDLANDS
LATE WEDNESDAY. ONLY LIQUID RAIN IS EXPECTED ACROSS THE I-20
CORRIDOR AND POINTS SOUTH.
BEHIND THIS SYSTEM, VERY COLD AIR RETURNS FOR THE REMAINDER OF
THE WEEK. LIKE MANY OF OUR COLD SYSTEMS THIS SEASON, THIS
DOESN'T LOOK LIKE A RECORD SETTER BY ANY MEANS, BUT CONFIDENCE
IS HIGH IN BELOW AVERAGE TEMPS; EC EFI HIGHLIGHTS THIS NICELY
WITH CONSISTENT HIGH AND LOW TEMP EFI'S BETWEEN 0.7 AND 0.9
FROM WEDNESDAY THROUGH FRIDAY.
AVIATION /07Z MONDAY THROUGH FRIDAY/
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD.
PRESSURE GRADIENT WILL CONTINUE TO WEAKEN EARLY THIS MORNING,
WHICH WILL HELP TO LOWER SUSTAIN WINDS ALONG WITH WIND GUSTS
THROUGH SUNRISE. GENERALLY THE TAF LOCATIONS WILL SEE SUSTAINED
WINDS OUT OF THE WEST/NORTHWEST MAINLY AROUND 10 KNOTS AND
GUSTS UP TO 18 KNOTS THROUGH SUNRISE. THROUGH THE DAY, WINDS
GENERALLY LESS THAN 10 KNOTS OUT OF THE WEST/NORTHWEST, THEN
TURNING LIGHT AND VARIABLE FOR THE OVERNIGHT HOURS. SKY AND
VISIBILITIES WILL REMAIN VFR THROUGH THE TAF PERIOD AS DRY HIGH
PRESSURE WILL SETTING INTO THE REGION.
EXTENDED AVIATION OUTLOOK... AN APPROACHING SYSTEM ON
WEDNESDAY AND THURSDAY WILL BRING SOME PRECIPITATION AND
ASSOCIATED RESTRICTIONS.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
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