143
FXUS61 KLWX 020105
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
905 PM EDT WED JUL 1 2026
WHAT HAS CHANGED
CONFIDENCE REMAINS HIGH FOR INTENSE HEAT THURSDAY AND FRIDAY.
HEAT HEADLINES REMAIN IN EFFECT FOR BOTH DAYS. HIGH HEAT WILL
REMAIN AROUND FOR INDEPENDENCE DAY AS WELL, BUT CONFIDENCE IS
NOT HIGH ENOUGH FOR HEADLINES THIS FAR OUT IN ADVANCE. THE OTHER
THREAT WILL BE INCREASING CHANCES FOR STRONG TO SEVERE STORMS
FRIDAY THROUGH THE WEEKEND.
KEY MESSAGES
- (1) EXTREME HEAT AND HUMIDITY BUILDS OVER THE REGION THROUGH THE
INDEPENDENCE DAY HOLIDAY WEEKEND.
- (2) THUNDERSTORM CHANCE INCREASE THROUGH THIS WEEKEND, WITH
AN INCREASED RISK FOR SEVERE THUNDERSTORMS FRIDAY INTO THE
INDEPENDENCE DAY WEEKEND.
DISCUSSION
KEY MESSAGE 1...EXTREME HEAT BUILDS OVER THE REGION THROUGH THE
INDEPENDENCE DAY HOLIDAY WEEKEND.
THE SUBTROPICAL RIDGE WILL CONTINUE TO BUILD OVERHEAD THROUGH
SATURDAY. THE HIGHEST HEIGHTS ARE PROGGED TO BE OVERHEAD
THURSDAY AND FRIDAY, AND THIS IS REFLECTIVE IN MOST GUIDANCE
LOW-LEVEL TEMPERATURES BEING PROGGED TO BE A COUPLE DEGREES
HOTTER THAN WEDNESDAY. THEREFORE, MAX TEMPERATURES WILL BE AT
LEAST A FEW DEGREES HOTTER FOR THURSDAY AND FRIDAY COMPARED TO
WEDNESDAY.
HEAT ADVISORIES AND EXTREME HEAT WARNINGS HAVE BEEN ISSUED FOR
THURSDAY AND FRIDAY WHERE CONFIDENCE IS HIGH IN VERY HOT/HUMID
CONDITIONS. ADDITIONAL HEAT ADVISORIES MAY BE NEEDED FOR EVEN
THE HIGHER ELEVATIONS OF THE ALLEGHENIES. THURSDAY AND FRIDAY
LOOK TO BE NEAR LOCKS FOR HIGH TEMPERATURES OVER 100 DEGREES.
IAD COULD POTENTIALLY CHALLENGE DAILY RECORD HIGH TEMPERATURES
EACH DAY THROUGH SATURDAY, WHILE DCA AND BWI COULD CHALLENGE
THEIR DAILY RECORD HIGHS THURSDAY THROUGH SATURDAY. FOR MORE
HISTORICAL CONTEXT, SEE THE CLIMATE SECTION AT THE BOTTOM OF THE
FORECAST DISCUSSION.
THIS UPPER RIDGE WILL START TO SLOWLY BREAK DOWN HEADING INTO
THIS WEEKEND, WHICH WILL OPEN THE DOOR FOR THE DEVELOPMENT OF
THUNDERSTORMS ACROSS THE REGION (SEE KEY POINT 2 BELOW).
IT LOOKS AS THOUGH THE HEAT AND HUMIDITY WILL LIKELY HOLD ON
THROUGH THE WEEKEND AS WELL. HOWEVER, FORECAST CONFIDENCE IN THE
EXACT HIGH TEMPERATURES STARTS TO DECREASE A BIT, AS BOTH
REMNANT CLOUD COVER FROM THUNDERSTORMS ON PREVIOUS DAYS AND
THUNDERSTORMS FROM THE DAY OF COULD IMPACT TEMPERATURES. AS OF
NOW, THE CURRENT FORECAST CALLS FOR HIGH TEMPERATURES IN THE
UPPER 90S/LOWER 100S AT LOWER ELEVATIONS ON SATURDAY
(INDEPENDENCE DAY), AND MID 90S TO NEAR 100 ON SUNDAY.
OVERNIGHT LOW TEMPERATURES EACH NIGHT WILL BE IN THE 70S FOR
MOST, WITH LOWER 80S IN THE URBAN CENTERS. AS A RESULT, THERE
WILL BE VERY LITTLE RELIEF FROM THE HEAT OVERNIGHT.
KEY MESSAGE 2...THUNDERSTORM CHANCE INCREASE THROUGH THIS WEEKEND,
WITH AN INCREASED RISK FOR SEVERE THUNDERSTORMS FRIDAY THROUGH
INDEPENDENCE DAY WEEKEND.
CONVECTION THIS EVENING HAS REMAINED WELL OFF TO THE NORTH THIS
EVENING, BUT THE LATEST SATELLITE STILL SHOWS SOME CU BUILDUP IN
NORTHEAST MARYLAND NEAR THE BAY BREEZE BOUNDARY. AN ISOLATED
SHOWER/T-STORM CANNOT BE RULED OUT OVER THIS AREA, BUT
CONFIDENCE IS VERY LOW. ELSEWHERE, NO CONVECTION IS EXPECTED.
AN EVEN STRONGER CAP IS FORECAST ON THURSDAY, RESULTING IN DRY
CONDITIONS FOR ALL.
UPPER-LEVEL RIDGING WILL GRADUALLY BUCKLE FRIDAY BEFORE FLATTENING
OVER THE WEEKEND INTO EARLY NEXT WEEK AS THE BROAD SUBTROPICAL
RIDGE SHIFTS FURTHER OFFSHORE AND A SERIES OF SHORTWAVE
DISTURBANCES PIVOT THROUGH. TIMING AND COVERAGE OF STORMS HAVE
YET TO BE DETERMINED GIVEN THE PLACEMENT OF SYNOPTIC/MESOSCALE
FEATURES. WITH THAT SAID, LOOKING AT SCATTERED STRONG TO SEVERE
THUNDERSTORMS MAINLY DURING THE AFTERNOON AND EVENING PERIOD
WITH DAMAGING WIND GUSTS, LARGE HAIL, HEAVY RAINFALL, AND
FREQUENT LIGHTNING AS THE MAIN THREATS. STORMS MAY BE OF THE
PULSE VARIETY LIKELY FORMING ALONG THE LEE SIDE TROUGH EAST OF
THE ALLEGHENIES OR RESIDUAL OUTFLOWS (I.E THE BAY/RIVER BREEZE)
DUE TO THE LACK SHEAR ALOFT FRIDAY INTO SATURDAY. OF COURSE THIS
IS SUBJECT TO CHANGE BASED ON ANY DISTURBANCES THAT MOVE
THROUGH AS THE RIDGE STARTS TO BREAK DOWN. IF THIS WERE TO
OCCUR, WE COULD BE LOOKING AT MORE ORGANIZED AND WIDESPREAD
STORM CLUSTERS, BUT CONFIDENCE IN THIS IS LOW AT THIS TIME.
AS WE APPROACH THE INDEPENDENCE DAY WEEKEND, HAVE A WEATHER
PREPAREDNESS PLAN READY TO GO, ESPECIALLY IF YOU ARE OUTDOORS
(I.E AT A PICNIC WITH FAMILY OR A FIREWORKS SHOW). PLAN AHEAD
FOR ANY OUTDOOR ACTIVITIES THIS WEEKEND, AS THEY ARE LIKELY TO
BE INTERRUPTED BY STORMS AT SOME POINT. HAVE A WAY TO GET
TRUSTED WARNINGS, DOWNLOAD A RADAR/LIGHTNING APP TO KEEP AWARE
OF CHANGING WEATHER CONDITIONS, AND KNOW WHEN TO ACT. WHEN
THUNDER ROARS, GO INDOORS. LIGHTNING CAN STRIKE UP TO 15 MILES
OUTSIDE OF THE CORE OF THUNDERSTORMS, SO WAIT 30 MINUTES AFTER
THAT LAST RUMBLE OF THUNDER BEFORE RESUMING OUTDOOR ACTIVITIES.
GIVEN THE HEAT IN PLACE, SOME STORMS COULD BE QUITE INTENSE (IF
THEY FORM). FROM A HISTORICAL PERSPECTIVE, PROLONGED NEAR RECORD
HEAT IN SUMMER OFTEN ENDS IN A PERIOD OF STRONG STORMS. INTENSE
STORMS CAN PRODUCE HAIL AND HIGH WINDS IN ADDITION TO RAIN AND
LIGHTNING, SO HAVING ACCESS TO STURDY SHELTER IS IMPORTANT.
THERE IS A GROWING SIGNAL THAT THE TRUE BREAKDOWN OF THE UPPER RIDGE
DOESN'T OCCUR UNTIL EARLY NEXT WEEK. THIS WILL RESULT IN A DROP IN
TEMPERATURES, BUT WILL ALSO PUT US RIGHT WITHIN THE TRANSITION ZONE
BETWEEN RIDGING TO OUR WEST AND TROUGHING TO OUR NORTHEAST. A
CONTINUED THREAT FOR MCSS AROUND THE UPPER PERIPHERY OF THE RIDGE
COULD BRING SEVERE THUNDERSTORMS INTO THE REGION THROUGH EARLY NEXT
WEEK AS WELL. CONFIDENCE IS VERY LOW AT THIS TIME, BUT IT IS A
POSSIBILITY THAT AT LEAST SOME PORTIONS OF THE AREA ARE DEALING WITH
THUNDERSTORMS INTO MONDAY AND PERHAPS TUESDAY.
AVIATION /00Z THURSDAY THROUGH MONDAY/
VFR CONDITIONS ARE LIKELY TO PREVAIL FOR THE MOST PART THROUGH
THURSDAY NIGHT. LIGHT AND VARIABLE WINDS WILL LIKELY TURN TO THE
NORTHWEST THURSDAY MORNING BEFORE BECOMING LIGHT AND VARIABLE
AGAIN THURSDAY NIGHT.
PREVAILING VFR CONDITIONS ARE GENERALLY EXPECTED ON BOTH FRIDAY AND
SATURDAY. INTERMITTENT SUB-VFR CONDITIONS RETURN FRIDAY AFTERNOON
AND EVENING AND AGAIN SATURDAY AFTERNOON/EVENING AS
THUNDERSTORM CHANCES INCREASE. SHOULD THUNDERSTORMS MATERIALIZE,
SOME COULD BECOME SEVERE RESULTING IN ERRATIC CHANGES IN WIND
SPEED AND DIRECTIONS, POTENTIALLY EXCEEDING 50 KNOTS.
ADDITIONALLY, STORMS WOULD COME WITH THE LIKELIHOOD OF FREQUENT
LIGHTNING AND THE CHANCE FOR SOME HAIL. TIMING WILL GENERALLY BE
DURING THE MID- LATE AFTERNOON THROUGH EVENING HOURS EACH DAY,
WITH FURTHER WEST AREAS EARLIER AND THE METROS LATER.
MARINE
AN SCA REMAINS IN EFFECT UNTIL 2 AM FOR THE MIDDLE PORTION OF
THE BAY AND LOWER TIDAL POTOMAC RIVER FOR SOUTHERLY CHANNELING.
ELSEWHERE, WINDS WILL BE LIGHT.
ADDITIONAL CHANNELING IS POSSIBLE THURSDAY INTO THE WEEKEND
ALTHOUGH INTENSITY GRADUALLY DROPS OFF EACH DAY. THUNDERSTORM
CHANCES INCREASE FRIDAY AFTERNOON, AND ESPECIALLY BY SATURDAY
AND SUNDAY AFTERNOONS. ANY THUNDERSTORM WILL BE CAPABLE OF
PRODUCING STRONG WIND GUSTS, POTENTIALLY IN EXCESS OF 50 KNOTS,
AS WELL AS FREQUENT LIGHTNING AND HAIL. TIMING OF STORMS IS
STILL A BIT UNCERTAIN, BUT SHOULD GENERALLY BE DURING THE MID-
LATE AFTERNOON THROUGH THE EVENING HOURS, AS IS TYPICAL WITH
SUMMER CONVECTION.
CLIMATE
THERE IS A SIGNIFICANT HEAT RISK THIS WEEK. THE NUMBERS BELOW
AREN'T A FORECAST, BUT RATHER A REFERENCE FOR HISTORICAL CONTEXT
FOR COMPARISON. LATEST FORECAST: WEATHER.GOV/LWX. NOTE THAT
DULLES DID BREAK A RECORD TODAY WITH THE HIGH TEMPERATURE OF 97
DEGREES (JULY 1, 2026).
==================================================================
*** 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 22, 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)
==================================================================
*** DAILY RECORD HIGHS | WARM LOWS ***
VALID: JUL 04
==================================================================
BALTIMORE 100 (2002 + 2) | 78 (1911)
WASHINGTON 100 (1919) | 80 (2018 + 2002)
STERLING-DULLES AIRPORT 97 (2002 + 1999) | 75 (2018)
BALTIMORE DOWNTOWN 101 (2002 + 1990) | 83 (2002)
ANNAPOLIS 98 (1999) | 81 (2018)
HAGERSTOWN 100 (1966 + 1919) | 76 (2018)
MARTINSBURG 103 (1898) | 76 (1999)
CHARLOTTESVILLE 100 (2012) | 78 (1919)
-----------------------------------------------------------------
NUMBER OF CONSECUTIVE DAYS MAX TEMP >=100
AREA (OBS SITE) RECORDS SINCE
------------------------------------------------------------------
BALTIMORE (BWI) 4 DAYS JULY 14-17,2024 & JULY 19-22,1930
WASHINGTON (DCA) 4 DAYS JULY 14-17, 2024 & JULY 5-8, 2012
STERLING-DULLES (IAD) 2 DAYS JULY 7-8, 2012, JULY 21-22, 2011
JULY 6-7, 2010, JULY 16-17, 1997
BALTIMORE DOWNTOWN (DMH) 5 DAYS JULY 3-7, 2010 & JULY 7-11, 1993
ANNAPOLIS (NAK) 1 DAY JULY 21, 2019, JULY 7, 2012,
JULY 22, 2011, JUNE 29, 1959
HAGERSTOWN (HGR) 3 DAYS JULY 5-7, 2010
MARTINSBURG (MRB) 6 DAYS JUNE 1-6, 1925
CHARLOTTESVILLE (CHO) 5 DAYS JULY 4-8, 2012
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...EXTREME HEAT WARNING FROM 10 AM TO 8 PM EDT THURSDAY FOR
DCZ001.
EXTREME HEAT WARNING FROM 10 AM TO 8 PM EDT FRIDAY FOR DCZ001.
MD...EXTREME HEAT WARNING FROM 10 AM TO 8 PM EDT THURSDAY FOR
MDZ003>006-008-011-013-014-016>018-502>508.
EXTREME HEAT WARNING FROM 10 AM TO 8 PM EDT FRIDAY FOR
MDZ003>006-008-011-013-014-016>018-502>508.
HEAT ADVISORY FROM 10 AM TO 8 PM EDT THURSDAY FOR MDZ501.
HEAT ADVISORY FROM 10 AM TO 8 PM EDT FRIDAY FOR MDZ501.
VA...EXTREME HEAT WARNING FROM 10 AM TO 8 PM EDT THURSDAY FOR
VAZ037>040-050-051-053>057-501-502-505-506-526-527.
EXTREME HEAT WARNING FROM 10 AM TO 8 PM EDT FRIDAY FOR
VAZ027>031-036>040-050-051-053>057-501-502-505-506-526-
527.
HEAT ADVISORY FROM 10 AM TO 8 PM EDT THURSDAY FOR VAZ025>031-
036-504.
HEAT ADVISORY FROM 10 AM TO 8 PM EDT FRIDAY FOR VAZ025-026-504.
WV...EXTREME HEAT WARNING FROM 10 AM TO 8 PM EDT THURSDAY FOR
WVZ051>053.
EXTREME HEAT WARNING FROM 10 AM TO 8 PM EDT FRIDAY FOR
WVZ050>053-055-502-504.
HEAT ADVISORY FROM 10 AM TO 8 PM EDT THURSDAY FOR WVZ050-055-
502>504-506.
HEAT ADVISORY FROM 10 AM TO 8 PM EDT FRIDAY FOR WVZ503-506.
MARINE...EXTREME HEAT WARNING FROM 10 AM TO 8 PM EDT THURSDAY FOR
ANZ530.
EXTREME HEAT WARNING FROM 10 AM TO 8 PM EDT FRIDAY FOR ANZ530.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT THURSDAY FOR ANZ531>534-
537>543.
DISCUSSION...BJL/CJL/KJP/KRR
AVIATION...BJL/CJL/KJP/KRR
MARINE...BJL/CJL/KJP/KRR
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