348
FXUS62 KRAH 190525
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
125 AM EDT THU MAR 19 2026
WHAT HAS CHANGED
AS OF 115 AM THURSDAY...
* UPDATED DETAILS ON TIMING AND CHARACTERIZATION OF MONDAY'S
COLD FRONT.
KEY MESSAGES
AS OF 115 AM THURSDAY...
1) A CHANCE OF SHOWERS AND STORMS WILL EXIST WITH THE PASSAGE
OF A POLAR FRONT NEXT MONDAY, WITH A FOLLOWING RISK OF
FROST/LIGHT FREEZING CONDITIONS IN CONTINENTAL POLAR HIGH
PRESSURE NEXT TUE-TUE NIGHT.
DISCUSSION
AS OF 115 AM THURSDAY...
KEY MESSAGE 1...
A CHANCE OF SHOWERS AND STORMS WILL EXIST WITH THE PASSAGE OF A
POLAR COLD FRONT NEXT MONDAY, WITH A FOLLOWING RISK OF
FROST/LIGHT FREEZING CONDITIONS IN CONTINENTAL POLAR HIGH
PRESSURE NEXT TUE-TUE NIGHT.
THERE IS STRONG MODEL AGREEMENT THAT THE MID/UPR-LEVEL PATTERN
WILL BECOME LESS-AMPLIFIED AND QUASI-ZONAL ACROSS THE MID-
LATITUDES THROUGH THE WEEKEND, AS THE RECORD-BREAKING SUB-
TROPICAL HIGH OVER THE SOUTHWEST AND SOCAL BREAKS DOWN. WITHIN
THAT DEVELOPING FAST/ QUASI-ZONAL FLOW REGIME, A SHORTWAVE
TROUGH WILL PROGRESS FROM THE NERN N. PACIFIC INLAND AND ACROSS
THE INTERNATIONAL BORDER VICINITY THROUGH THE WEEKEND, THEN
MODESTLY AMPLIFY FROM THE GREAT LAKES TO THE NORTHEAST EARLY
NEXT WEEK - THOUGH BOTH DETERMINISTIC AND ENSEMBLE MODEL SPREAD
IS HIGH REGARDING THE TIMING AND AMPLITUDE OF THAT FEATURE, NOT
SURPRISING GIVEN THE FAST, QUASI-ZONAL NATURE OF THE FLOW.
DETERMINISTIC GUIDANCE IS GENERALLY FASTER THAN ENSEMBLE MEANS,
WITH THE LATTER FAVORED BY WPC. ALSO NOTEWORTHY WITHIN THAT WNW
FLOW REGIME IS THAT AN ELEVATED MIXED LAYER FROM THE NRN AND
CNTL ROCKIES WILL LIKELY BE ADVECTED ACROSS THE SRN MIDDLE
ATLANTIC AND CAROLINAS SUN NIGHT AND MON.
AT THE SURFACE, AN EXPANSIVE, CONTINENTAL-SOURCED HIGH NOW
EXTENDING THROUGHOUT THE MIDDLE AND SOUTH ATLANTIC STATES WILL
BE CENTERED OVER THE FL PENINSULA AND ADJACENT GULF AND SWRN
ATLANTIC BASINS THROUGH THE WEEKEND. THE LOCATION AND EXPANSE OF
THE HIGH WILL LIMIT MOISTURE ADVECTION AHEAD OF AND INTO A
POLAR FRONT THAT WILL MOST LIKELY MOVE ACROSS CNTL NC ON MON.
THE PREFERRED SLOWER TIMING OF THE PARENT SHORTWAVE TROUGH
NOTED ABOVE, AND ALSO THE FAST BIAS OF MODELS ADVECTING CP AIR
EAST OF THE APPALACHIANS, SUGGEST TEMPERATURES ON MON WILL
CONTINUE WELL ABOVE AVERAGE. DESPITE THE WARM TEMPERATURES, THE
AFOREMENTIONED LIMITED MOISTURE RETURN AHEAD OF THE FRONT WILL
LIKELY YIELD SURFACE DEWPOINTS IN THE 50S F, TO PERHAPS AROUND
60 F IN THE SANDHILLS AND SRN-CNTL COASTAL PLAIN. RELATED
BUOYANCY WILL BE LIMITED/WEAK, AND POSSIBLY CAPPED TO DEEP
CONVECTION BY THE EML WITH NWWD EXTENT/AWAY FROM THE RELATIVELY
RICHEST LOW-LEVEL MOISTURE (IE. ~60F SURFACE DEWPOINTS). SO
WHILE THE FAST WNWLY FLOW/SHEAR PROFILES AND THE PRESENCE OF THE
EML WOULD BOTH PROVIDE A CONDITIONALLY SUPPORTIVE ENVIRONMENT
FOR SEVERE CONVECTION, THE RELATIVE LACK OF LOW-LEVEL MOISTURE
AND BUOYANCY SHOULD MITIGATE THAT POTENTIAL, EVEN AS
PREDICTABILITY INCREASES WITH TIME.
IT WILL TURN MARKEDLY COOLER AND BELOW AVERAGE ONCE AGAIN
BEHIND THE COLD FRONT THROUGH THE MIDDLE OF NEXT WEEK, UNDER THE
INFLUENCE OF CP HIGH PRESSURE THAT WILL WEAKEN/MODIFY WHILE
MIGRATING FROM THE NRN PLAINS TO THE MIDDLE ATLANTIC. LOW
TEMPERATURES WILL LIKELY BE SUPPORTIVE OF FROST/LIGHT FREEZING
CONDITIONS AND A CATEGORY OR TWO COLDER THAN NBM/OFFICIAL
FORECAST ONES, WHICH AT PRESENT DEPICT MOSTLY UPR 30S-LWR 40S.
AVIATION /05Z THURSDAY THROUGH MONDAY/
AS OF 115 AM THURSDAY...
VFR CONDITIONS PREVAIL WITH LIGHT AND VARIABLE SURFACE WINDS
THIS MORNING BECOMING NORTHWEST TO WESTERLY BY THIS AFTERNOON.
BKN/OVC MID/UPPER-LVL CLOUD LAYER AS LOW AS 6 KFT WILL SPREAD
ACROSS THE AREA THIS MORNING.
OUTLOOK: VFR CONDITIONS LIKELY TO PREVAIL THROUGH THE OUTLOOK
PERIOD WITH OVERALL LIGHT AND VARIABLE WINDS. AN AREA OF
DECAYING LIGHT RAIN WILL BE POSSIBLE EARLY SAT MORNING (MOST
PROBABLE AT RDU AND RWI WITH A 20% CHANCE), BUT SUB-VFR
CONDITIONS ARE UNLIKELY AT THIS TIME. SOUTHWEST WINDS INCREASE
THIS WEEKEND AND MAY BECOME GUSTY AT TIMES AHEAD OF AND
ESPECIALLY BEHIND A STRONG COLD FRONTAL PASSAGE AND WIND SHIFT
ON MON; SHOWERS AND ISOLATED STORMS MAY ACCOMPANY THE FROPA.
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...MWS
AVIATION...AS
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