140
FXUS62 KRAH 192338
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
640 PM EST SUN JAN 19 2025
SYNOPSIS
ARCTIC HIGH PRESSURE WILL BUILD IN TONIGHT AND BRING BITTER COLD
TEMPERATURES INTO THE REGION THROUGH THE MIDDLE OF THE WEEK.
NEAR TERM /THROUGH TONIGHT/
AS OF 312 PM SUNDAY...
WITH THE SURFACE LOW OVER THE REGION, AND EXITING TO THE NORTHEAST,
A FEW LINGERING ISOLATED SHOWERS MAYBE EVEN A RUBLE OF THUNDER IN
THE SOUTHERN COUNTIES WILL PASS BY THIS AFTERNOON BEFORE CLEARING
THE REGION. AS THE COLD FRONT SWEEPS ACROSS THE REGION AS THE
SURFACE LOW EXITS, EXPECT INCREASING WIND GUSTS. A FEW SURFACE
OBSERVATIONS TO THE SOUTHWEST OF THE AREA HAVE ALREADY REPORTED
GUSTS OF 28 TO 35 KNOTS. WE CAN EXPECT THESE GUSTS TO SPREAD INTO
OUR REGION AS THE UPPER LEVEL TROUGH SHIFTS OVER THE REGION AND
BRINGS A STRONG NORTHWESTERLY WIND. AS THE RAIN AND CLOUDS EXIT,
COLD DRY AIR AND AS MENTION BEFORE GUST WIND WILL FILTER INTO
CENTRAL NC. TEMPERATURES WILL QUICKLY DROP THIS EVENING WITH LOWS IN
THE UPPER TEENS IN THE NW PIEDMONT, LOW 20S AROUND THE TRIANGLE
AREA, AND MID/UPPER 20S ACROSS THE SANDHILLS AND SOUTHERN COASTAL
PLAIN. WITH GUSTY WINDS OVERNIGHT, EXPECT OUR FIRST ROUND OF WINDS
CHILLS IN THE SINGLE DIGIT TO MID/UPPER TEENS ACROSS THE REGION
EARLY MONDAY MORNING.
SHORT TERM /MONDAY AND MONDAY NIGHT/
AS OF 345 PM SUNDAY...
..FIRST DAY OF BITTERLY COLD TEMPERATURES
CONTINUED 925 TO 850 MB CAA WILL PROMOTE COLD TEMPERATURES MONDAY
WITH HIGHS MAXING OUT IN THE MID TO UPPER 20S (NW) TO LOWER TO MID
30S (SE). RESIDUAL GUSTY NW SFC WINDS EARLY MONDAY WILL SUBSIDE
SOME BY THE AFTERNOON PERIOD. HOWEVER, FORECAST SOUNDINGS INDICATE
SOME STIRRING OF WINDS WILL BE POSSIBLE THROUGH THE OVERNIGHT PERIOD
(ESPECIALLY ACROSS THE COASTAL PLAIN). WITH OVERNIGHT LOWS DROPPING
INTO THE MID TO UPPER TEENS, WITH PERHAPS SOME STIRRING OF THE
WINDS, THERE COULD BE A FEW HOURS OF BELOW 10 DEGREE APPARENT
TEMPERATURES BEFORE SUNRISE TUESDAY MORNING. AS SUCH, WE'LL HAVE TO
MONITOR FOR A POTENTIAL COLD WEATHER ADVISORY FOR SOME OUR AREA
MONDAY NIGHT/EARLY TUESDAY MORNING. OTHERWISE EXPECT DRY AND COLD
CONDITIONS THIS PERIOD.
LONG TERM /TUESDAY THROUGH SUNDAY/
AS OF 420 PM SUNDAY...
* FORECAST CONFIDENCE REMAINS HIGH FOR A CONTINUATION OF WELL BELOW
AVERAGE TEMPERATURES AND DANGEROUSLY COLD CONDITIONS THROUGH MOST
OF THE WORK WEEK, MAXIMIZED WITH DEPARTURES FROM NORMAL OF 15-25 F
TUE-THU.
* FORECAST CONFIDENCE HAS INCREASED REGARDING THE NORTHERN EXTENT OF
(WINTRY) PRECIPITATION ACROSS E-CNTL NC --WITH ABOVE AVERAGE
CONFIDENCE OF ONLY LIGHT ACCUMULATIONS-- AS WEAK AND SOUTHWARD-
SUPPRESSED LOW PRESSURE TRACKS FROM THE GULF OF MEXICO TO WELL
OFFSHORE THE SOUTH AND SOUTHERN MIDDLE ATLANTIC COASTS TUE-EARLY
WED.
A HIGHLY AMPLIFIED MID/UPR-LEVEL PATTERN WILL BE CHARACTERIZED BY A
REX BLOCKING RIDGE OVER THE ERN PACIFIC AND MEAN TROUGHS THAT WILL
PIVOT ACROSS THE CNTL-ERN US, THE DEEPEST OF WHICH --AND MOST
INFLUENTIAL FOR MAINLY LIGHT SNOW OVER E-CNTL NC-- WILL BE THE LEAD
ONE OVER THE ERN US TUE-WED. THE ASSOCIATED, POSITIVELY-TILTED AND
AT LEAST PARTIALLY PHASED TROUGH WILL EXTEND FROM THE UPR GREAT
LAKES TO THE GULF OF CA AT 12Z TUE AND PIVOT ACROSS AND OFFSHORE THE
SOUTH AND SRN MIDDLE ATLANTIC THROUGH WED. IN THE SWLY FLOW
DOWNSTREAM OF THAT TROUGH, AN INTENSE UPR-LEVEL JET IS FORECAST TO
STRENGTHEN AND NEAR OR EXCEED 200 KTS FROM THE SRN MIDDLE ATLANTIC
TO JUST OFFSHORE ATLANTIC CANADA. A BROAD ZONE OF DIVERGENCE WITHIN
THE ELONGATED RIGHT ENTRANCE REGION OF THIS JET WILL BE PRINCIPALLY
RESPONSIBLE FOR DEEP ASCENT ACROSS AND OFFSHORE THE SOUTHEAST TUE-
TUE NIGHT, WHERE LOW-LEVEL AGEOSTROPHIC RESPONSE WILL FOCUS
CONVERGENCE AND ISENTROPIC LIFT. LOW AMPLITUDE SHORTWAVE RIDGING
WILL THEN PROGRESS ACROSS AND OFFSHORE THE MIDDLE AND SOUTH ATLANTIC
LATER WED-WED NIGHT, DOWNSTREAM OF A TROUGH THAT WILL RELOAD AND
PIVOT FROM THE GREAT PLAINS AND MS VALLEY TO THE EAST COAST THROUGH
FRI. RISING HEIGHTS BUT CONTINUED STRONG/FAST, QUASI-ZONAL WILL THEN
PREVAIL ACROSS THE SRN US AND CAROLINAS NEXT WEEKEND.
AT THE SURFACE, ARCTIC HIGH PRESSURE WILL INITIALLY SPRAWL FROM THE
CNTL GREAT BASIN TO THE MIDDLE ATLANTIC, THEN GRADUALLY WEAKEN AS IT
MIGRATES EWD AND BECOMES CENTERED OVER THE MIDDLE ATLANTIC THROUGH
THE END OF THE WEEK. A WAVY FRONTAL ZONE WILL BE SUPPRESSED WELL-
SOUTHWARD ACROSS THE SUB-TROPICS, FROM THE GULF OF MEXICO TO THE
SWRN N. ATLANTIC, ALONG THE SRN/EQUATORWARD DRAPE OF THE EXPANSIVE
ARCTIC HIGH AND AIRMASS THROUGH MID-WEEK; AND MODEL AGREEMENT
REMAINS HIGH REGARDING ONLY WEAK/FLAT FRONTAL WAVE DEVELOPMENT ALONG
THAT FRONTAL ZONE FROM THE GULF OF MEXICO TO OFFSHORE THE SOUTH
ATLANTIC COAST TUE-TUE NIGHT. THE AFOREMENTIONED RE-LOADING OF THE
TROUGH ALOFT INITIALLY INTO THE CNTL US MAY ALLOW THE SURFACE
FRONTAL ZONE AND SUBSEQUENT CYCLOGENESIS TO BUCKLE POLEWARD AND
NEARER THE MIDDLE ATLANTIC COAST LATER IN THE WEEK, WITH POSSIBLE
ADDITIONAL, LOW CONFIDENCE PRECIPITATION IMPACTS INTO CNTL NC
CENTERED AROUND THU-THU NIGHT. THE GFS AND GEM DETERMINISTIC MODELS
AND A SMALL PERCENTAGE OF THEIR ENSEMBLE MEMBERS ARE MOST BULLISH/
WESTWARD ACROSS THE ERN HALF OF NC WITH THIS SYSTEM, WHILE THEIR
OTHER MEMBERS, AND MOST OF THE EC AND ECS, ARE FARTHER OFFSHORE.
UNCERTAINTY WILL LIKELY REMAIN HIGH UNTIL THAT TROUGH ALOFT IS
BETTER SAMPLED ACROSS NOAM AND ASSIMILATED INTO FORECAST MODELS IN
THE NEXT COUPLE OF DAYS.
MODEL GUIDANCE HAS BECOME MUCH MORE TIGHTLY-CLUSTERED WITH THE TUE
NIGHT SYSTEM AND FOCUS MAINLY LIGHT MEASURABLE SNOW ACROSS THE ERN
CAROLINAS, WITH A LIGHT DUSTING POSSIBLE AS FAR NORTHWEST AS A LINE
FROM NEAR ALBEMARLE TO RALEIGH TO ROANOKE RAPIDS, RANGING TO AROUND
AN INCH OR TWO ALONG THE COAST. THE GREATEST CHANCE OF AROUND ONE
INCH ACCUMULATION IN CNTL NC WILL BE IN SAMPSON AND WAYNE COUNTIES,
WHERE LATEST PROBABILITIES OF GREATER THAN AN INCH ARE AROUND 60
PERCENT. ANY ACCUMULATION, HOWEVER LIGHT, MAY RESULT IN SLICK AND
LOCALIZED HAZARDOUS TRAVEL CONDITIONS DUE TO VERY COLD, ANTECEDENT
AIR AND GROUND TEMPERATURES.
VERY COLD CONDITIONS, AND DRY ONES WED-WED NIGHT, WILL THEN
GRADUALLY MODERATE INTO THE UPCOMING WEEKEND, AS THE ARCTIC HIGH AND
AIRMASS GRADUALLY WEAKEN AND LOSE INFLUENCE. AS THE ARCTIC AIR DOES
SO, HOWEVER, SUFFICIENTLY COLD AIR MAY REMAIN IN PLACE TO PRESENT
ADDITIONAL P-TYPE CONCERNS AS MOISTURE IS DRAWN NWWD WITH THE
AFOREMENTIONED OFFSHORE FRONTAL ZONE AND POSSIBLE RENEWED
CYCLOGENESIS NEAR THE MIDDLE ATLANTIC COAST THU-THU NIGHT. GIVEN THE
AFOREMENTIONED HIGH UNCERTAINTY DURING THAT TIME, JUST A SLIGHT TO
SMALL CHANCE OF A WINTRY MIX WILL BE ADVERTISED MAINLY OVER THE ERN
HALF OF CNTL NC THU-THU NIGHT, WITH FOLLOWING DRY CONDITIONS FRI
THROUGH THE WEEKEND.
AVIATION /00Z MONDAY THROUGH FRIDAY/
AS OF 640 PM SUNDAY...
GUSTY WNW WINDS AT 15-25KT WILL CONTINUE INTO THE NIGHT, BEFORE
DIMINISHING TO AROUND 10KT BETWEEN 04Z AND 08Z. WINDS WILL THEN
INCREASE AGAIN TO 10-20KT BY 15Z MONDAY. EXPECT VFR CONDITIONS
TONIGHT AND MONDAY.
OUTLOOK: VFR CONDITIONS ARE EXPECTED MONDAY AND TUESDAY. FORECAST
UNCERTAINTY IS HIGH, HOWEVER A POTENTIAL LIGHT SNOW EVENT COULD
AFFECT THE KFAY AREA TUESDAY NIGHT. OTHERWISE, GENERALLY VFR
CONDITIONS ARE EXPECTED THROUGH THE PERIOD.
CLIMATE
RECORD LOW MAXIMUM TEMPERATURES:
JANUARY 20:
KGSO: 29/1983
KRDU: 28/1970
JANUARY 21:
KFAY: 31/1983
JANUARY 22:
KGSO: 29/2014
KRDU: 27/1970
JANUARY 23:
KGSO: 28/1954
KFAY: 30/1970
RECORD LOW MINIMUM TEMPERATURES:
JANUARY 23:
KRDU: 8/1977
KFAY: 9/1970
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...BADGETT
NEAR TERM...CA
SHORT TERM...LUCHETTI
LONG TERM...MWS
AVIATION...BADGETT
CLIMATE...RAH
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