079
FXUS62 KRAH 311821
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
221 PM EDT MON AUG 31 2026
WHAT HAS CHANGED
* SLIGHTLY INCREASED THE CHANCE FOR AN ISOLATED SHOWER/STORM
FROM THE VIRGINIA BORDER THROUGH THE TRIAD AND AS FAR SOUTH AS
THE TRIANGLE FOR THIS AFTERNOON.
* NO MAJOR CHANGES WERE MADE TO THE FORECAST HEADING INTO THE
HOLIDAY WEEKEND.
KEY MESSAGES
AS OF 220 PM MONDAY...
1) ANOMALOUSLY HOT TEMPERATURES EXPECTED TO PERSIST THROUGH
THURSDAY AND PERHAPS INTO FRIDAY.
2) LABOR DAY WEEKEND THROUGH MONDAY GRADUALLY TRENDS COOLER AND
DRIER WITH A LINGERING CHANCE OF SHOWERS AND STORMS.
DISCUSSION
AS OF 220 PM MONDAY...
KEY MESSAGE 1... ANOMALOUSLY HOT TEMPERATURES EXPECTED TO
PERSIST THROUGH THURSDAY AND PERHAPS INTO FRIDAY.
A DEEP SUBTROPICAL RIDGE OF AROUND 595 DAM CENTERED OVER THE
MID-MISSISSIPPI VALLEY IN THE 12Z H5 RAOBS THIS MORNING IS
FORECAST TO STRENGTHEN AS IT WOBBLES GRADUALLY EASTWARD AND
STRETCHING OVER THE CAROLINAS BY THURS MORNING. HIGHLY ANOMALOUS
H850 TEMPERATURES (AT-OR-ABOVE THE 99.5 PERCENTILE) INITIALLY
DIRECTED OVER THE MID-MISSISSIPPI VALLEY TODAY, WILL GRADUALLY
WARM TO AROUND 20-22C AND SLOWLY BE DIRECTED OVER THE SOUTHERN
MID-ATLANTIC WED THROUGH FRI. THIS PATTERN IS HIGHLY FAVORABLE
FOR AN EARLY SEPTEMBER HEAT WAVE WITH MINIMAL CONVECTIVE CHANCES
DUE TO INFLUENCE FROM THE STRONG SUBTROPICAL RIDGE.
LOW-LVL THICKNESSES AND DIABATIC TECHNIQUES LINE UP WITH
STATISTICAL GUIDANCE AND SUPPORTS WIDESPREAD MID/UPPER 90S AS
EARLY AS TUES, BUT ESPECIALLY WED INTO FRI. A FEW LOCATIONS MAY
REACH TRIPLE DIGIT AIR TEMPERATURES, BUT WIDESPREAD GTE 100
DEGREES IS NOT EXPECTED. HEAT INDEX VALUES IN THE UPPER 90S TO
AROUND 105 DEGREES ARE EXPECTED EACH DAY WITH AREAS SOUTH AND
EAST OF RALEIGH MOST PROBABLE TO SURPASS 105 DEGREES FOR SEVERAL
HOURS DUE TO BETTER LOW-LVL MOISTURE IN PLACE. TARGETED HEAT
ADVISORIES APPEAR LIKELY. INCREASING CONVECTIVE CHANCES,
AN APPROACHING COLD FRONT AND NORTHEAST FLOW IN ITS WAKE SHOULD
PUT AN END TO THE HEAT BY SUN.
KEY MESSAGE 2...LABOR DAY WEEKEND THROUGH MONDAY GRADUALLY
TRENDS COOLER AND DRIER WITH A LINGERING CHANCE OF SHOWERS AND
STORMS.
ENSEMBLE GUIDANCE IS INDICATING THAT THE HOT ANOMALOUS RIDGE OF
HIGH PRESSURE OVER THE AREA WILL GRADUALLY SHIFT WESTWARD THIS
COMING HOLIDAY WEEKEND. MUCH OF THE GUIDANCE IS PROJECTING THE
RIDGE WILL SHIFT INTO THE MIDWEST TO CENTRAL PLAINS OF THE US BY
SATURDAY.
AS THE RIDGE SHIFTS WEST, TROUGHING ACROSS THE MID-ATLANTIC AND
NE US IS FAVORED TO TAKE OVER. THIS TROUGHING WILL BE
ASSOCIATED WITH A COLD FRONT THAT APPROACHES SATURDAY AND IS
FORECAST TO PUSH THROUGH BY SUNDAY. DEPENDING ON HOW THE PATTERN
EVOLVES, SOME MODELS SUGGEST COOL 1026-MB HIGH PRESSURE COULD
EXTEND INTO THE AREA BY LABOR DAY, FAVORING HIGHS FOR THE LATTER
PART OF THIS WEEKEND AND INTO MONDAY IN THE LOW TO MIDDLE 80S.
DEWPOINTS COULD DIP INTO THE 50S ON MONDAY, A WELCOME CHANGE.
AHEAD OF THE FRONT, WE SHOULD SEE STORM CHANCES INCREASE. THOSE
CHANCES MAY INITIALLY START FRIDAY WITH A PRE-FRONTAL TROUGH,
BUT BETTER COVERAGE IS EXPECTED SATURDAY AHEAD OF THE FRONT.
ISOLATED OR SCATTERED STORMS COULD LINGER INTO SUNDAY, THOUGH
DRIER CONDITIONS ARE FAVORED AS WE HEAD INTO LABOR DAY. RIGHT
NOW, WE ARE NOT OUTLOOKED FROM SPC. HOWEVER, THEIR LONG-RANGE
DISCUSSION DOES INDICATE A POSSIBLE SEVERE RISK OVER THE
CAROLINAS SATURDAY AHEAD OF THE FRONT. PREDICTABILITY, HOWEVER,
IS TOO LOW AT THIS TIME, BUT WILL BE MONITORED AS WE GO THROUGH
THE WEEK.
AVIATION /18Z MONDAY THROUGH SATURDAY/
AS OF 200 PM MONDAY...
PREVAILING VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE
24 HOUR TAF PERIOD. ISOLATED TO SCATTERED SHOWERS AND PERHAPS
INFREQUENT LIGHTNING WILL BE POSSIBLE AROUND THE VA/NC BORDER
THIS AFTERNOON, AND PERHAPS AS FAR SOUTH AS RDU/RWI, BUT BETTER
CHANCES AROUND GSO/INT. MARGINAL INSTABILITY AND WEAK SHEAR
SHOULD ONLY RESULT IN SHORT-LIVED SHOWERS WITH ADDITIONAL
DEVELOPMENT POSSIBLE ALONG SUBSEQUENT OUTFLOW BOUNDARIES. SHOWER
ACTIVITY SHOULD QUICKLY ABATE AROUND SUNSET WITH LOSS OF
DIURNAL HEATING. LINGERING LOW LEVEL MOISTURE ACROSS THE COASTAL
PLAIN AND SANDHILLS MAY RESULT IN ANOTHER ROUND OF LIFR
STRATUS/MIST OR FOG EARLY TUES MORNING, BUT CONFIDENCE IS LOW
ENOUGH TO PRECLUDE ADDITION IN THE 18Z TAFS; MOST PROBABLE AT
FAY.
OUTLOOK: AFTERNOON CONVECTION WILL LIKELY BE SUPPRESSED TUESDAY
THROUGH THURSDAY WITH MOSTLY FAIR WEATHER CU AROUND 5-8 KFT
DURING THE AFTERNOON HOURS. LIGHT AND VARIABLE WINDS PERSIST
GENERALLY OUT OF THE SOUTHWEST. SHOWER/STORM CHANCES INCREASE
FRI AND ESPECIALLY SAT AS THE RIDGE BREAKS DOWN AND A COLD FRONT
APPROACHES FROM THE NORTH-NORTHEAST ON SAT.
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...AS/KREN
AVIATION...AS
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