683
FXUS62 KRAH 171034
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
630 AM EDT SUN MAY 17 2026
WHAT HAS CHANGED
* NO SIGNIFICANT CHANGES.
KEY MESSAGES
AS OF 115 AM SUNDAY...
1) HOT AND MAINLY DRY THROUGH WEDNESDAY.
2) INCREASINGLY UNSETTLED STARTING WED NIGHT, WITH MORE SEASONABLE
TEMPERATURES.
DISCUSSION
AS OF 115 AM SUNDAY...
KEY MESSAGE 1... HOT AND MAINLY DRY THROUGH WEDNESDAY.
STILL ANTICIPATING MULTIPLE DAYS OF ANOMALOUSLY HOT TEMPERATURES.
MID-UPPER LEVEL TROUGHING HOLDING FROM SOUTH-CENTRAL CANADA THROUGH
THE NORTHERN PLAINS AND ROCKIES WILL ENSURE PERSISTENT RIDGING OVER
AND OFF THE SOUTHEAST COAST THROUGH MID WEEK, WITH HEIGHTS OVER NC
REACHING THE 95TH-99TH PERCENTILE TODAY THROUGH TUE. MEANWHILE, AT
THE SURFACE, BERMUDA HIGH PRESSURE CONTINUES TO EXTEND WESTWARD
ACROSS NC, KEEPING LOW LEVEL MOISTURE RETURN LIMITED, WITH DEEP
MIXING EACH DAY AND MINIMAL CLOUDINESS OVERALL. MULTI-MODEL LOW
LEVEL THICKNESSES ARE PROJECTED TO BE 15-20 M ABOVE NORMAL TODAY AND
TO GRADUALLY RISE TO 20-25 M ABOVE NORMAL BY WED, FAVORING HIGHS
FROM AROUND 90 TO THE MID 90S. EARLY-DAY DEWPOINTS IN THE 60S ARE
LIKELY TO MIX OUT AND DROP THROUGH THE 50S DURING THE HOTTEST PARTS
OF EACH DAY, WHICH SHOULD KEEP HEAT INDEX VALUES FROM RISING INTO
THE TRIPLE DIGITS. HOWEVER, THIS KIND OF EARLY-SEASON HEAT CAN STILL
BE UNEXPECTEDLY DANGEROUS, AS PEOPLE HAVE NOT YET BECOME ACCLIMATED
TO THE HOT WEATHER. THE DAILY EXPERIMENTAL HEAT RISK IS EXPECTED TO
TOP OUT AT MODERATE (LEVEL 2 OF 4), INDICATING THAT THIS KIND OF
HEAT IS QUITE UNUSUAL FOR THIS TIME OF YEAR AND HAS HISTORICALLY LED
TO HIGH LEVELS OF HEAT ILLNESS. A MODERATE LEVEL OF HEAT RISK
SUGGESTS THAT IMPACTS ARE LIKELY FOR SENSITIVE INDIVIDUALS AND THOSE
WITHOUT ADEQUATE COOLING. AND WITH JUST A MODEST BREEZE AND FAIRLY
HIGH SUNSHINE EACH DAY, THE WBGT INDEX WILL ALSO BE ELEVATED, SO
SPENDING TIME IN THE SHADE IS ENCOURAGED.
REGARDING PRECIP CHANCES, THE MID LEVEL RIDGING AND LIMITED LOW
LEVEL MOISTURE SHOULD KEEP ANY SHOWERS VERY ISOLATED THROUGH WED.
THE ONE EXCEPTION COULD BE LATER TODAY OR THIS EVENING AS WEAK MCVS
FROM FL CONVECTION SPREAD NNW THEN NNE INTO THE WESTERN CAROLINAS,
POTENTIAL SUPPORTING ISOLATED SHOWERS IN THE FAR W PIEDMONT,
ALTHOUGH THE PWS WILL BE CLOSE TO NORMAL WITH A CAP AT 700 MB, SO
ANY CONVECTION SHOULD BE VERY LOW IN COVERAGE, TOO LOW TO INCLUDE IN
THE FORECAST AT THIS TIME.
KEY MESSAGE 2... INCREASINGLY UNSETTLED STARTING WED NIGHT, WITH
MORE SEASONABLE TEMPERATURES.
RAIN CHANCES WILL INCREASE AS WE GET INTO MID WEEK, ALTHOUGH AMOUNTS
AND TIMING REMAIN UNCERTAIN. THE SOUTH-CENTRAL CANADA PORTION OF THE
MID LEVEL TROUGH WILL TRACK E OVER ONTARIO, QUEBEC, AND MARITIME
PROVINCES WED/THU AND TAMP DOWN THE SOUTHEAST RIDGE, ALLOWING A COOL
SURFACE HIGH TO SPREAD ACROSS THE GREAT LAKES AND ST LAWRENCE VALLEY
AND PUSH A BACKDOOR FRONT S INTO NC THU. MOST DETERMINISTIC MODELS
AND ENSEMBLE MEMBERS FAVOR HIGH RAIN CHANCES THU AFTERNOON INTO
EARLY FRI, AS THE HIGH BEGINS TO WEDGE SOUTHWARD WITH INCREASED GULF-
AND ATLANTIC-SOURCE OVERRUNNING, GREATEST OVER THE W CWA INTO W NC
WHERE LREF PROBABILITIES OF A HALF INCH THU AFTN THROUGH FRI MORNING
ARE HIGHEST AT 45-60%.
WHILE CONFIDENCE IS FAIRLY HIGH IN A WEDGE REGIME LASTING INTO FRI,
THE LATEST MODELS STILL DISAGREE ON ITS DISSOLUTION, WITH THE LREF
MEMBERS SHOWING A 15+ DEGREE SPREAD IN 2M TEMPS BOTH FRI AND SAT
AFTERNOON, A REFLECTION OF HIGH UNCERTAINTY REGARDING THE CAD
PERSISTENCE, WHICH WILL ALSO INFLUENCE RAIN CHANCES AS WE MAINTAIN A
SOMEWHAT WEAK BUT WAVY WSW FLOW ALOFT AMIDST ABOVE-NORMAL PW. WILL
RETAIN ABOVE-NORMAL POPS FRI AFTERNOON THROUGH THE WEEKEND, BUT WITH
LOW CONFIDENCE IN DETAILS.
AVIATION /10Z SUNDAY THROUGH THURSDAY/
AS OF 630 AM SUNDAY...
TAF PERIOD: THERE IS A MINIMAL CHANCE FOR BRIEF MVFR/IFR CEILINGS AT
FAY AROUND SUNRISE. OTHERWISE, HIGH CLOUDS THIS MORNING SHOULD
DECREASE IN COVERAGE BY EARLY AFTERNOON. SOUTHWEST WIND WILL
INCREASE WITH GUSTS BY LATE MORNING. BY SUNSET, THE WIND GUSTS WILL
DECREASE AND THE WIND WILL BACK TO SOUTHERLY.
OUTLOOK: THE POTENTIAL FOR MVFR/IFR STRATUS AROUND SUNRISE WILL
CONTINUE OVER THE NEXT FEW DAYS AT FAY/RWI. A CHANCE OF SHOWERS WILL
ENTER THE FORECAST WEDNESDAY NIGHT, WITH WIDESPREAD SHOWERS AND A
CHANCE OF THUNDERSTORMS EXPECTED AT ALL SITES THURSDAY.
CLIMATE
RECORD HIGH TEMPERATURES:
MAY 18: KGSO: 95/1911 KRDU: 95/1906 KFAY: 96/1911
MAY 19: KGSO: 96/1911 KRDU: 95/1962 KFAY: 96/2022
MAY 20: KGSO: 95/1917 KRDU: 96/2022 KFAY: 99/2022
RECORD HIGH MINIMUM TEMPERATURES:
MAY 18: KGSO: 70/2015 KRDU: 72/1896 KFAY: 71/2018
MAY 19: KGSO: 68/2018 KRDU: 70/2022
MAY 20: KGSO: 68/2022 KRDU: 69/2019 KFAY: 71/2022
MAY 21: KGSO: 67/2022 KRDU: 71/1898 KFAY: 71/2025
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...HARTFIELD
AVIATION...GREEN
CLIMATE...RAH
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