330
FXUS61 KLWX 131426 AAA
AFDLWX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1026 AM EDT MON JUL 13 2026
WHAT HAS CHANGED
NOTHING.
KEY MESSAGES
- 1) QUIESCENT WEATHER TO START THE WEEK WITH HEAT BUILDING.
- 2) FORECAST CONFIDENCE DECREASES SUBSTANTIALLY LATE THIS WEEK
INTO THE UPCOMING WEEKEND, BUT THE POTENTIAL IS THERE FOR BOTH
EXTREME HEAT AND SEVERE THUNDERSTORMS.
DISCUSSION
KEY MESSAGE 1... QUIESCENT WEATHER TO START THE WEEK WITH HEAT
BUILDING.
DRY CONDITIONS ARE EXPECTED TODAY THROUGH AT LEAST WED (LIKELY
LONGER). HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH MIDWEEK,
WITH HEAT GRADUALLY BUILDING. WHILE TEMPS START BELOW AVERAGE
TODAY, THEY WILL BE ABOVE AVERAGE BY TUE AND WELL ABOVE AVERAGE
BY WED. CANNOT RULE OUT HEAT ADVISORIES WED, BUT IT DOES LOOK
LIKE A DRIER HEAT THAN WHAT WAS EXPERIENCED AROUND THE 4TH OF
JULY.
KEY MESSAGE 2...FORECAST CONFIDENCE DECREASES SUBSTANTIALLY LATE THIS
WEEK INTO THE UPCOMING WEEKEND, BUT THE POTENTIAL IS THERE FOR BOTH
EXTREME HEAT AND SEVERE THUNDERSTORMS.
MODEL GUIDANCE IS IN REASONABLY GOOD AGREEMENT THAT THE LONGWAVE
PATTERN ACROSS THE CONUS LATE THIS WEEK INTO THE UPCOMING WEEKEND
WILL FEATURE TROUGHING ACROSS THE PACIFIC NW, RIDGING OVER THE
CENTER OF THE COUNTRY, AND THEN TROUGHING DOWNSTREAM ACROSS NEW
ENGLAND. SUCH A PATTERN WILL PLACE US IN NW'LY FLOW ALOFT.
HOWEVER, THERE'S CONSIDERABLE DISAGREEMENT REGARDING THE
PLACEMENT OF INDIVIDUAL SHORTWAVES AND THEIR ASSOCIATED SFC
FRONTS THROUGHOUT THAT PERIOD. AS A RESULT, THERE'S A HIGHLY
ATYPICAL AMOUNT OF FORECAST SPREAD FOR THIS TIME OF YEAR DURING
THAT TIME WINDOW. ENSEMBLE GUIDANCE HAS MEMBERS SHOWING HIGHS
ANYWHERE FROM THE UPPER 70S TO THE MID 100S EACH DAY FRI THROUGH
SUN, WITH ABOVE AVERAGE SPREAD ON THU AS WELL (MID 80S TO MID
100S). SO DEPENDING ON WHICH SOLUTION VERIFIES, WE COULD HAVE
ANYWHERE FROM WELL BELOW NORMAL TEMPS TO RECORD HIGHS EACH DAY.
DRY CONDITIONS ARE EXPECTED ON THU, BUT CHANCES FOR
STORMS START TO INCREASE FOR FRI, SAT, AND SUN. DEPENDING ON
HOW THE PATTERN EVOLVES, AND WHICH SIDE OF THE FRONTAL BOUNDARY
WE END UP ON, THERE COULD BE A POTENTIAL THREAT FOR SEVERE
THUNDERSTORMS. THE FORECAST TEMP SPREAD ILLUSTRATES THE
UNSEASONABLE AMOUNT OF BAROCLINICITY THAT WILL BE PRESENT, WHICH
SHOULD TRANSLATE INTO UNSEASONABLY STRONG WIND FIELDS ALOFT AS
WELL. IF WE END UP ON THE WARM, UNSTABLE SIDE OF THE BOUNDARY,
THE THREAT WOULD LIKELY BE THERE FOR SEVERE THUNDERSTORMS, WITH
MCSS POSSIBLE IN NW'LY FLOW ALOFT. SPC CURRENTLY HAS MUCH OF
THE FORECAST AREA HIGHLIGHTED IN A 15 PERCENT CONTOUR FOR SEVERE
THUNDERSTORMS ON FRI, AND WXNEXT2 AI GUIDANCE HIGHLIGHTS
ADDITIONAL THREATS FOR SEVERE THUNDERSTORMS ON BOTH SAT AND
SUN. WE'LL NEED TO MONITOR TRENDS OVER THE COURSE OF THE WEEK,
SINCE THIS IS A VERY CONDITIONAL THREAT AT THE MOMENT, GIVEN THE
ATYPICALLY HIGH AMOUNT OF FORECAST UNCERTAINTY.
AVIATION /14Z MONDAY THROUGH FRIDAY/
MONITORING POTENTIAL FOR FOG NEAR CHO THROUGH DAYBREAK. MRB
COULD ALSO SEE SOME FOG, BUT THIS IS MORE QUESTIONABLE AS THEY
WERE NOT DIRECTLY HIT WITH RAIN YESTERDAY.
AFTER THIS MORNING, VFR THROUGH MIDWEEK.
PREVAILING VFR CONDITIONS AND LIGHT NORTHWESTERLY WINDS ARE EXPECTED
ON BOTH THURSDAY AND FRIDAY. AN AFTERNOON THUNDERSTORM MAY BE
POSSIBLE ON FRIDAY.
MARINE
SUB-SCA WINDS THROUGH MIDWEEK WITH HIGH PRESSURE OVERHEAD.
SUB-SCA LEVEL NW'LY WINDS ARE EXPECTED ON BOTH THU AND FRI.
SMWS MAY BE NEEDED FRI IF STORMS MOVE OVER THE WATERS.
TIDES/COASTAL FLOODING
ONSHORE TO S'LY FLOW CONTINUES THROUGH MIDWEEK, KEEPING TIDAL
LEVELS ELEVATED. THE UPCOMING NEW MOON IS ALSO ACCENTUATING THE
TIDE CYCLE. WIDESPREAD ADVISORIES FOR MINOR TIDAL FLOODING,
THOUGH ANNAPOLIS COULD EVEN APPROACH MODERATE FLOOD STAGE, BUT
MOST LIKELY REMAINS BELOW.
GUIDANCE DOES INDICATE GRADUALLY DECLINING ANOMALIES THROUGH MID
WEEK, BUT ANNAPOLIS IN PARTICULAR MAY REQUIRE A DAY OR TWO MORE
OF ADVISORIES ON THE ASTRONOMICALLY HIGHER TIDE.
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
DISCUSSION...LFR/KJP/CPB
AVIATION...LFR/KJP/CPB
MARINE...LFR/KJP/CPB
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