361
FXUS62 KRAH 181046
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
600 AM EST MON NOV 18 2024
SYNOPSIS
OFFSHORE HIGH PRESSURE WILL EXTEND ACROSS THE SOUTH ATLANTIC STATES
AHEAD OF A STRONG COLD FRONT THAT WILL MOVE THROUGH THE REGION
WEDNESDAY NIGHT. COLDER CONDITIONS WILL FOLLOW FOR LATE WEEK.
NEAR TERM /TODAY AND TONIGHT/
AS OF 235 AM MONDAY...
PARTLY SUNNY AND WARM TODAY. TEMPERATURES 5-8 DEGREES ABOVE NORMAL.
STRONG SUB-TROPICAL HIGH PRESSURE ALOFT WILL REMAIN OVER THE SE
UNITED STATES THROUGH TONIGHT. THE RIDGE AXIS WILL REMAIN TO OUR
WEST ENSURING DRY WEATHER AND WARM TEMPERATURES. THERE WILL BE A FEW
CIRRUS FROM TIME TO TIME; HOWEVER, PARTLY TO MOSTLY SUNNY SKIES WILL
CONTINUE TODAY AND PARTLY CLOUDY SKIES TONIGHT. HIGHS TODAY WILL BE
MOSTLY IN THE LOWER 70S. LOWS TONIGHT 45-50.
SHORT TERM /TUESDAY AND TUESDAY NIGHT/
AS OF 235 AM MONDAY...
INCREASING CLOUDINESS, LOW CHANCE OF SHOWERS LATE TUESDAY IN THE
WEST. CONTINUED WARM.
THE RIDGE AXIS AT THE SURFACE AND ALOFT WILL SLOWLY MOVE OVER THE
REGION TUESDAY MORNING REACHING THE COAST LATE IN THE DAY AND
TUESDAY NIGHT. THIS WILL ALLOW DEEPER MOISTURE TO INCREASE ACROSS
THE REGION, ESPECIALLY IN THE MID AND UPPER LEVELS. EXPECT SKIES TO
BECOME MOSTLY CLOUDY TUESDAY. THERE IS A CHANCE OF SHOWERS VERY LATE
TUESDAY AFTERNOON AND TUESDAY NIGHT, ESPECIALLY IN THE WEST AIDED BY
WEAKENING DISTURBANCES ALOFT. HIGHS TUESDAY MAY BE A DEGREE OR TWO
COOLER - IF THE CLOUDINESS ARRIVES AS EXPECTED. HIGHS IN THE UPPER
60S TO LOWER 70S. THE CHANCE OF SHOWERS REMAINS AT 30-50 PERCENT
LATE TUESDAY AND TUESDAY NIGHT, HIGHEST IN THE WEST. LOWS WILL BE
MILD, MOSTLY IN THE 50S.
LONG TERM /WEDNESDAY THROUGH SUNDAY/
AS OF 202 AM MONDAY...
* STRONG COLD FRONTAL PASSAGE WED NIGHT, WITH A CONDITIONAL ISOLATED
SEVERE THREAT
* MUCH COLDER THU INTO SAT, WITH WSW TO WNW WINDS BRISK AT TIMES OF
25-35 MPH
WE CONTINUE TO TRACK A STRONG COLD FRONTAL PASSAGE SET TO MOVE
THROUGH WED NIGHT. MUCH OF THE GUIDANCE REMAINS IN GOOD AGREEMENT
THAT THE FRONT MOVES THROUGH BETWEEN 6 PM AND 1 AM. A VIGOROUS MID-
LEVEL SHORTWAVE TROUGH OVER THE UPPER MS VALLEY AND GREAT LAKES IS
FORECAST TO TRACK INTO THE OH VALLEY AND MID-ATLANTIC BY EARLY THU.
MOST GUIDANCE SUGGESTS SOME LIGHT RAIN MAY PERSIST INTO LATE MORNING
ALONG/EAST OF US-1 TIED TO WEAK ISENTROPIC ASCENT IN THE 700-500 MB
LAYER. THIS IS THEN FORECAST TO MOVE OUT BY MIDDAY, OWING TO ONE
LAST MILD DAY IN THE UPPER 60S TO LOW 70S.
AS THE FRONT APPROACHES FROM THE WEST WED EVENING, STRONG HEIGHT
FALLS AND DPVA WILL OVERSPREAD THE REGION. THERE STILL APPEARS TO BE
A SHORT WINDOW OF TIME WHEN SHEAR/INSTABILITY COULD OVERLAP AHEAD OF
THE FRONT TO FAVOR A CONDITIONAL SEVERE THREAT. WHAT REMAINS
CONDITIONAL IS THE AMOUNT OF INSTABILITY, AS WELL AS THE FACT THAT
THE DEEPER MOISTURE WILL SHIFT TOWARD THE COAST BY EVENING, LEAVING
A POTENTIAL LACK OF OVERLAP OF KINEMATICS AND THERMODYNAMICS. HIGH-
END AMOUNTS OF MLCAPE APPROACH ~ 500 J/KG, WITH LOW END AMOUNTS OF A
FEW HUNDRED J/KG. SHEAR IS NOT LACKING, WITH 50-60 KT IN THE 0-6 KM
LAYER, ~ 30 KT OF 0-3 KM, AND 20-25 KT OF 0-1 KM. IT WOULD APPEAR
MOST GUIDANCE SHOWS A POSSIBLE ISOLATED/BROKEN LINE OF SHOWERS
TRACKING EAST BETWEEN ABOUT 6 PM AND MIDNIGHT, THOUGH WHETHER ANY
STORMS COULD BECOME SURFACE BASED IS STILL UNCLEAR. A LOOK AT HIGH-
RES CAMS IN THE COMING DAYS WILL BE HELPFUL TO BETTER ASSESS THE
ENVIRONMENT.
IT STILL APPEARS MUCH COLDER THU INTO SAT AS THE VIGOROUS TROUGH
ROTATES CYCLONICALLY OVER THE MID-ATLANTIC AND NE US INTO SAT. HIGH
TEMPERATURES THU-SAT WILL BE SOME 15-20 DEGREES COLDER COMPARED TO
WED IN THE LOW TO MID/UPPER 50S, COOLEST ON FRI WITH STRONG CAA IN
PLACE. BRISK WSW TO WNW WINDS WILL BE IN PLACE AS WELL, GUSTING AT
TIMES TO BETWEEN 25 AND 35 MPH, HIGHEST ON FRI. GUIDANCE SHOWS THAT
RIDGING OR QUASI-ZONAL FLOW MAY BUILD IN SUN, WHICH SHOULD ALLOW A
SLIGHT MODERATION IN THE AIRMASS WITH MID 50S TO NEAR 60. LOWS FRI
AND SUN MORNING COULD APPROACH FROST/FREEZE POTENTIAL IN THE LOW TO
MID 30S, WITH PERHAPS THE BEST CHANCE SUN MORNING WITH HIGH PRESSURE
BUILDING IN WITH LIGHTER SFC WINDS.
AVIATION /12Z MONDAY THROUGH FRIDAY/
AS OF 600 AM MONDAY...
GENERALLY VFR CONDITIONS UNDER HIGH PRESSURE WILL CONTINUE THROUGH
12Z/TUESDAY. THERE IS A CHANCE OF A BRIEF PERIOD OF MVFR FOG THROUGH
13Z TODAY. ANY FOG THAT DEVELOPS SHOULD MIX OUT BY MID MORNING, WITH
ONLY HIGH CLOUDS IN PLACE THROUGH THE END OF THE TAF PERIOD.
OUTLOOK: A STRONG COLD FRONT MOVING THROUGH THE REGION WILL BRING A
CHANCE OF SHOWERS AND ASSOCIATED SUB-VFR RESTRICTIONS TO THE AREA
LATE TUESDAY INTO WEDNESDAY. VFR CONDITIONS ARE EXPECTED TO RETURN
LATE WEDNESDAY AFTERNOON. A DEEPENING AREA OF LOW PRESSURE INVOF THE
GREAT LAKES WILL YIELD FREQUENT GUSTS OF 20 TO 30 KTS THURSDAY AND
AGAIN ON FRIDAY.
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...BADGETT
NEAR TERM...BADGETT
SHORT TERM...BADGETT
LONG TERM...KREN
AVIATION...BADGETT
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