957
FXUS61 KLWX 261833
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
233 PM EDT FRI JUN 26 2026
WHAT HAS CHANGED
ADDED A CLIMATE SECTION TO PROVIDE HISTORICAL CONTEXT FOR
SIGNIFICANT HEAT NEXT WEEK. RAIN CHANCES HAVE INCREASED FOR
SUNDAY. MAJOR HEAT IS EXPECTED NEXT WEEK.
KEY MESSAGES
- (1) A WEAK FRONTAL BOUNDARY WILL LINGER ACROSS THE REGION
THROUGH SUNDAY, DELIVERING WAVES OF SHOWERS AND
THUNDERSTORMS.
- (2) EXCESSIVE HEAT AND HUMIDITY NEXT WEEK HEADING INTO THE
INDEPENDENCE DAY HOLIDAY.
DISCUSSION
KEY MESSAGE 1...A WEAK FRONTAL BOUNDARY WILL LINGER ACROSS THE REGION
THROUGH SUNDAY, DELIVERING WAVES OF SHOWERS AND THUNDERSTORMS.
AS OF 18Z/2PM EDT, SHOWERS AND THUNDERSTORMS WERE INITIATING
ALONG A SURFACE TROUGH/DIFFERENTIAL HEATING BOUNDARY AHEAD OF A
WEAK WAVE ALOFT NEAR AND JUST WEST OF I-81 FROM NEAR STRASBURG
TO STAUNTON VA. THIS AREA IS LIKELY TO EXPAND THANKS TO THE
ABOVE FORCING MECHANISMS AS WELL AS LOW-LEVEL MOISTURE ADVECTION
UP OVER TOP OF THE SURFACE TROUGH. STEEPENING LOW-LEVEL LAPSE
RATES ACROSS NORTHERN VA INTO CENTRAL/SOUTHERN MD (INCLUDING THE
DC AND BALTIMORE METROS) COUPLED WITH MODEST MID-LEVEL FLOW
SHOULD ALLOW FOR SOME WEAK CLUSTERING/ORGANIZATION, WITH 45 TO
60 MPH GUSTS POSSIBLE IN THE STRONGEST ACTIVITY THROUGH 8PM.
A BRIEF LULL IN ACTIVITY IS POSSIBLE EARLY TO MID EVENING IN THE
WAKE OF THESE INITIAL SHOWERS AND STORMS.
AS A WEAK SYNOPTIC COLD FRONT APPROACH FROM THE OH VALLEY AND
LOWER GREAT LAKES TONIGHT, IT WILL REPLACE THE SURFACE TROUGH
AND STALL OVERHEAD. CONTINUED MOIST ADVECTION ATOP THIS FRONT IS
LIKELY TO RESULT IN NUMEROUS SHOWERS AND A FEW THUNDERSTORMS
MUCH OF THE NIGHT. GIVEN INCREASING PWATS (1.75-2.00") AND STORM
MOTIONS PARALLEL TO THE FRONT, THERE IS A CHANCE FOR SOME HEAVY
RAINFALL AMOUNTS SHOULD STORMS FORM AND TRAIN. HREF/REFS MAX QPF
SHOWS POTENTIAL FOR ISOLATED AMOUNTS OF 1-3 INCHES, WHICH SHOULD
NOT RESULT IN FLOODING IN MOST CASES GIVEN ONGOING DROUGHT. ONE
EXCEPTION WOULD BE OVER URBAN/HYDROPHOBIC AREAS, SO THAT WILL
NEED TO BE CLOSELY MONITORED AS WAVES OF RAIN CROSS LATE TONIGHT
THROUGH SATURDAY MORNING.
ADDITIONAL ACTIVITY LIKELY FORMS ALONG THE FRONT SATURDAY
AFTERNOON INTO EVENING AFTER A BRIEF LULL. THE EXACT PLACEMENT
AND TIMING REMAINS A BIT UNCERTAIN, BUT THE GENERAL THEME IS FOR
IT TO BE A BIT FURTHER SOUTH THAN TONIGHT/SATURDAY MORNING.
SLIGHTLY COOLER AND DRIER AIR WILL TRY TO WORK IN FROM THE
NORTHEAST BY SUNDAY. RECENT GUIDANCE IS MORE HUMID AND ALSO
SLOWER WITH THE FRONTAL PROGRESSION. THIS PLACES AREAS WEST OF
I-95 IN A ZONE OF POTENTIAL SLOW-MOVING STORMS WITH HEAVY
DOWNPOURS. DEPENDING ON HOW MUCH RAIN FALLS OUT THAT WAY THE
NEXT COUPLE OF DAYS, THERE COULD POTENTIALLY BE SOME FLOOD
ISSUES. CONFIDENCE IS LOW SINCE GUIDANCE IS IN FLUX, BUT SUNDAY
NO LONGER LOOKS LIKE A "MAINLY DRY" DAY FOR MOST OF THE AREA.
KEY MESSAGE 2...EXCESSIVE HEAT AND HUMIDITY NEXT WEEK HEADING
INTO THE INDEPENDENCE DAY HOLIDAY.
LOOKING AT A PROLONGED SIGNIFICANT HEAT RISK ACROSS THE ENTIRE
REGION TUESDAY THROUGH THE INDEPENDENCE DAY HOLIDAY/WEEKEND.
STRONG/BROAD SUBTROPICAL HIGH PRESSURE AND A BUILDING UPPER-LEVEL
RIDGE WILL ALLOW TEMPERATURES AND HUMIDITY VALUES TO CLIMB
TOWARD RECORD LEVELS BY THE MIDDLE AND END OF NEXT WEEK.
TEMPERATURES START TO CLIMB TUESDAY AS THE UPPER-LEVEL RIDGE
EXPANDS EASTWARD FROM THE OHIO RIVER VALLEY. LOOK FOR HIGHS IN
THE 90S WITH HEAT INDICES RUNNING BETWEEN 95-100 DEGREES.
WEDNESDAY THROUGH FRIDAY WILL BE THE PEAK OF THE HEAT WITH
HIGHS FOR MOST IN THE UPPER 90S AND LOWER 100S. HEAT INDICES
EACH AFTERNOON WITH RUN BETWEEN 102-107 DEGREES WITH A FEW
READINGS AROUND 110 ALONG THE IMMEDIATE I-95 METRO CORRIDOR AND
DOWN ACROSS THE VA PIEDMONT REGION. MINIMAL RELIEF IS EXPECTED
ACROSS THE MOUNTAINS WITH HIGHS IN THE MID 80S TO LOW 90S AND
HEAT INDICES IN THE MID TO UPPER 90S AS THE HEAT PEAKS MID TO
LATE WEEK. NO RELIEF AT NIGHT EITHER WITH WIDESPREAD LOWS IN THE
UPPER 60S TO MID 70S (UPPER 70S-80 URBAN AREAS) WEDNESDAY
THROUGH SATURDAY. MORE AT WEATHER.GOV/LWX/HEAT.
EVEN WITH THAT SAID, THERE STILL REMAINS SOME SPREAD IN TEMPERATURE
DATA MID TO LATE NEXT WEEK. SOME OF THIS IS DUE TOP THE
PLACEMENT AND POSITIONING OF THE RIDGE ALONG WITH ANY T-STORM
CHANCES THAT MAY DEVELOP LATE NEXT WEEK.
RIGHT NOW, ANY CONVECTION LOOKS TO BE TIED TO THE MOUNTAINS
WEDNESDAY AND THURSDAY DUE IN PART TO THE TERRAIN INFLUENCE. WITH
EXCESSIVE HEAT AND HUMIDITY THERE WILL BE PLENTY OF INSTABILITY TO
WORK WITH. YOU COMBINE THIS WITH ANY POTENTIAL RIPPLES OF LOW
PRESSURE MOVING AROUND THE RIDGE OR A BAY/RIVER BREEZE TO GET
CONVECTIVE DEVELOPMENT. THIS IS ILLUSTRATED BY BOTH THE CSU/CIPS
OUTLOOKS ALONG WITH GOOGLE WXNEXT AI MODEL WHICH SUGGEST THE RISK
FOR SEVERE WEATHER DURING THE FRIDAY JULY 3RD AND SATURDAY JULY 4
TIMEFRAME. SOMETHING WE'LL CONTINUE TO MONITOR IN SUBSEQUENT
FORECAST SHIFTS. HISTORICALLY, NEAR RECORD SUMMER HEAT OFTEN
ENDS WITH WIDESPREAD STRONG THUNDERSTORM ACTIVITY, AND LATEST
GUIDANCE STARTS TO BREAK DOWN THE HEAT NEXT WEEKEND (JULY 4).
AVIATION /18Z FRIDAY THROUGH WEDNESDAY/
CONVECTION HAD IGNITED ALONG AN AXIS FROM JUST WAS OF FRR TO VBW
AS OF 18Z. THIS WILL EXPAND A BIT AND HEAD EAST-NORTHEAST
THROUGH ROUGHLY 23Z. THE STRONGER STORMS MAY CONTAIN GUSTS
AROUND 40 KTS ALONG WITH REDUCED VSBY IN +RA AND LIGHTNING. IFR
REDUCTIONS ARE LIKELY TO BE BRIEF (15 MINS OR SO).
AFTER A BRIEF LULL, RAIN SHOWERS LIKELY BECOME MORE NUMEROUS
AFTER 03Z THIS EVENING DUE TO OVERRUNNING ATOP AN APPROACHING
COLD FRONT. A FEW THUNDERSTORMS ARE POSSIBLE, BUT COVERAGE SEEMS
A BIT LOW TO INCLUDE IN THE TAF JUST YET. WILL LIKELY NEED AMDS
FOR ISO TS OVERNIGHT INTO EARLY SAT AM. CIGS LOWER THROUGH SAT
AM AS WELL. GLAMP25/NAMNEST INDICATE SOME IFR CIGS OR EVEN
PATCHY DENSE FOG. CONDITIONS GRADUALLY IMPROVE THROUGH SAT PM,
THOUGH ADDITIONAL CONVECTION IS LIKELY MAINLY NEAR AND SW OF THE
METROS AS THE FRONT SLOWLY SAGS SOUTH. ADDITIONAL TS ARE POSSIBLE
SUNDAY, MAINLY NEAR MRB/CHO (WEST OF METROS FOR NOW).
PREVAILING VFR CONDITIONS ARE LIKELY MONDAY THROUGH THURSDAY
NEXT WEEK. LIGHT EASTERLY WINDS WILL BECOME SOUTHERLY TUESDAY
AND WEDNESDAY BEFORE TURNING SOUTHWESTERLY LATE WEEK.
MARINE
SHOWERS AND THUNDERSTORMS DEVELOPING OVER I-81 AS OF 2PM WILL
PROGRESS EAST ACROSS THE WATERS BETWEEN 5-8PM. SPECIAL MARINE
WARNINGS MAY BE NEEDED AS STORMS MOVE TOWARD THE WATERS. LIGHT
AND VARIABLE WINDS ARE EXPECTED OVER THE WATERS ON SATURDAY AS A
FRONTAL BOUNDARY STALLS ACROSS THE AREA. A FEW STORMS CAN'T BE
RULED OUT ON SATURDAY AS WELL. LIGHT NORTHEASTERLY WINDS ARE
FORECAST OVER THE WATERS FOR SUNDAY.
SUB-SCA LEVEL EAST TO SOUTHEAST FLOW IS EXPECTED MONDAY AS HIGH
PRESSURE BUILDS IN THE REGION. WINDS WILL BECOME MORE SOUTHERLY
TUESDAY BEFORE TURNING SOUTHWESTERLY MID TO LATE WEEKEND. SCA
CONDITIONS WILL BE TIED TO CHANNELING MAINLY OVER THE CHESAPEAKE
BAY TUESDAY AFTERNOON AND EVENING, AND AGAIN WEDNESDAY AFTERNOON
AND EVENING. THIS IS ESPECIALLY TRUE OVER THE MIDDLE AND OPEN
WATERS WHERE BRIEF SCA CONDITIONS ARE POSSIBLE DURING THIS TIME.
CLIMATE
THERE IS A SIGNIFICANT HEAT RISK NEXT WEEK. THE NUMBERS BELOW
AREN'T A FORECAST, BUT RATHER A REFERENCE FOR HISTORICAL CONTEXT
FOR COMPARISON. LATEST FORECAST: WEATHER.GOV/LWX.
==================================================================
*** ALL-TIME RECORD HIGHS ***
==================================================================
BALTIMORE 107 (SET ON JUL 10, 1936)
WASHINGTON 106 (SET ON JUL 20, 1930 + AUG 06, 1918)
STERLING-DULLES AIRPORT 105 (SET ON JUL 22, 2011)
BALTIMORE DOWNTOWN 108 (SET ON JUL 07, 2012 + JUL 22, 2011)
ANNAPOLIS 106 (SET ON AUG 06, 1918)
HAGERSTOWN 105 (SET ON JUL 14, 1954)
MARTINSBURG 112 (SET ON JUL 11, 1936)
CHARLOTTESVILLE 107 (SET ON SEP 07, 1954 + 3 OTHER TIMES)
==================================================================
*** ALL-TIME RECORD WARM LOWS ***
==================================================================
BALTIMORE 83 (SET ON AUG 05, 1930 + 2 OTHER TIMES)
WASHINGTON 84 (SET ON JUL 24, 2011 + 2 OTHER TIMES)
STERLING-DULLES AIRPORT 79 (SET ON AUG 08, 2007)
BALTIMORE DOWNTOWN 88 (SET ON JUL 02, 2011 AND JUL 10, 1993)
ANNAPOLIS 92 (SET ON JUL 07, 1994)
HAGERSTOWN 86 (SET ON JUN 15, 1899)
MARTINSBURG 86 (SET ON JUL 21, 1930)
CHARLOTTESVILLE 85 (SET ON AUG 07, 1918)
==================================================================
*** JULY MONTHLY RECORD HIGHS ***
==================================================================
BALTIMORE 107 (SET ON JUL 10, 1936)
WASHINGTON 106 (SET ON JUL 20, 1930)
STERLING-DULLES AIRPORT 105 (SET ON JUL 22, 2011)
BALTIMORE DOWNTOWN 108 (SET ON JUL 07, 2012 + JUL 22, 2011)
ANNAPOLIS 105 (SET ON JUL 21, 1930 + JUL 02, 1901)
HAGERSTOWN 105 (SET ON JUL 14, 1954)
MARTINSBURG 112 (SET ON JUL 11, 1936)
CHARLOTTESVILLE 107 (SET ON JUL 10, 1936 + JUL 20, 1930)
==================================================================
*** JULY MONTHLY RECORD WARM LOWS ***
==================================================================
BALTIMORE 83 (SET ON JUL 21, 1930)
WASHINGTON 84 (SET ON JUL 24, 2011 + 2 OTHER TIMES)
STERLING-DULLES AIRPORT 78 (SET ON JUL 24, 2010 + JUL 08, 2010)
BALTIMORE DOWNTOWN 88 (SET ON JUL 22, 2011 + JUL 10, 1993)
ANNAPOLIS 92 (SET ON JUL 07, 1994)
HAGERSTOWN 83 (SET ON JUL 24, 2010)
MARTINSBURG 86 (SET ON JUL 21, 1930)
CHARLOTTESVILLE 84 (SET ON JUL 22, 1930)
==================================================================
*** DAILY RECORD HIGHS | WARM LOWS ***
VALID: JUL 01
==================================================================
BALTIMORE 103 (1901) | 80 (1933 + 1901)
WASHINGTON 102 (1901) | 79 (1977)
STERLING-DULLES AIRPORT 96 (2012) | 72 (2017 + 3)
BALTIMORE DOWNTOWN 101 (2012) | 82 (2012)
ANNAPOLIS 103 (1901) | 79 (1945 + 1901)
HAGERSTOWN 100 (1901) | 74 (2017 + 1977)
MARTINSBURG 102 (1933) | 74 (1933)
CHARLOTTESVILLE 101 (2012 + 1945) | 78 (1901)
==================================================================
*** DAILY RECORD HIGHS | WARM LOWS ***
VALID: JUL 02
==================================================================
BALTIMORE 103 (1901) | 80 (1901)
WASHINGTON 101 (1898) | 79 (2012 + 1872)
STERLING-DULLES AIRPORT 98 (1966) | 75 (2022)
BALTIMORE DOWNTOWN 102 (1966) | 84 (2002)
ANNAPOLIS 105 (1901) | 80 (1901)
HAGERSTOWN 100 (1966) | 74 (2018 + 1901)
MARTINSBURG 102 (1933 + 1931) | 75 (1933 + 1901)
CHARLOTTESVILLE 100 (1954) | 76 (1910)
==================================================================
*** DAILY RECORD HIGHS | WARM LOWS ***
VALID: JUL 03
==================================================================
BALTIMORE 104 (1898) | 80 (1898)
WASHINGTON 101 (1966 + 2) | 80 (2018)
STERLING-DULLES AIRPORT 103 (1966) | 73 (2018 + 2)
BALTIMORE DOWNTOWN 102 (1997) | 82 (2018 + 1983)
ANNAPOLIS 100 (1901) | 84 (1896)
HAGERSTOWN 102 (1966) | 76 (2002)
MARTINSBURG 102 (1941 + 1911) | 74 (1980)
CHARLOTTESVILLE 100 (1966 + 1954) | 79 (1911)
..PERIOD OF RECORD (POR) CONTEXT
AREA (OBS SITE) RECORDS SINCE
------------------------------------------------------------------
BALTIMORE (BWI) JAN 1872
WASHINGTON (DCA) JUL 1872
STERLING-DULLES AIRPORT (IAD) JAN 1960
BALTIMORE DOWNTOWN (DMH) JUL 1950
ANNAPOLIS (NAK) JAN 1894
HAGERSTOWN (HGR) JAN 1899
MARTINSBURG (MRB) JAN 1891
CHARLOTTESVILLE (CHO) JAN 1893
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
DISCUSSION...ADS/DHOF/KJP/EST
AVIATION...ADS/DHOF/KJP/EST
MARINE...ADS/DHOF/KJP/EST
CLIMATE...DHOF
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