798
FXUS61 KLWX 160114
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
914 PM EDT WED JUL 15 2026
WHAT HAS CHANGED
HEAT ADVISORIES HAVE BEEN CANCELLED. NO MAJOR CHANGES TO THE CURRENT
FORECAST PACKAGE OUTSIDE OF ADDING IN SOME VISIBILITY REDUCTIONS
GIVEN CANADIAN WILDFIRE SMOKE DROPPING SOUTH INTO THE FORECAST AREA
LATE TONIGHT INTO THURSDAY.
KEY MESSAGES
- 1)HIGH HEAT AND HAZY SKIES LOOK TO CONTINUE THROUGH FRIDAY.
- 2)THUNDERSTORM CHANCES INCREASE THIS WEEKEND AND COULD POTENTIALLY
LINGER INTO SUNDAY AS A FRONT DROPS INTO THE REGION.
DISCUSSION
KEY MESSAGE 1...HIGH HEAT AND HAZY SKIES LOOK TO CONTINUE THROUGH
FRIDAY.
HEAT ADVISORIES HAVE BEEN ALLOWED TO EXPIRE WITH ADDITIONAL HEAT
HEADLINES POTENTIALLY NEEDED THURSDAY PENDING THE THICKNESS OF THE
CANADIAN WILDFIRE SMOKE SINKING SOUTH TONIGHT AND HOW MUCH MIXING
CAN OCCUR THURSDAY AFTERNOON. SIMILAR CONDITIONS ARE EXPECTED FRIDAY
MAKING THE TEMPERATURE/HEAT INDEX FORECAST MORE COMPLEX AS AN EVEN
THICKER PLUME OF CANADIAN WILDFIRE SMOKE DESCENDS UPON THE REGION.
CURRENT HI-RES GUIDANCE SUGGEST A STEADY INCREASE IN SMOKE
CONCENTRATIONS TONIGHT AS THE OUTFLOW FROM EARLIER STORMS OVER NJ/PA
FORCE SMOKE SOUTH INTO NORTHERN AND CENTRAL MD. CONCENTRATIONS WILL
CONTINUE TO INCREASE THURSDAY AS AN ADDITIONAL WAVE OF SMOKE IS SENT
SOUTHWARD FROM FIRES RAGING OVER QUEBEC AND WESTERN ONTARIO. WITH
THAT SAID, HI-RES GUIDANCE (SUCH AS THE RRFS-A AND HRRR) HINT AT
SOME SLIGHTLY LOWER AIR TEMPERATURES AND HIGHER DEWPOINTS THURSDAY
AND FRIDAY WHICH COULD NEGATE THE NEED FOR HEAT HEADLINES. THIS WILL
BE SOMETHING THAT WILL NEED TO MONITOR GIVEN WHAT PLAYED OUT EARLIER
TODAY WITH THE SMOKE ALOFT AND SUBDUED MIXING. WITH THE SMOKE, WILL
COME A FEW MORE DAYS OF POOR AIR QUALITY.THE RESPECTIVE AIR QUALITY
AGENCIES IN MD AND VA HAVE ISSUED CODE ORANGE AIR QUALITY ALERTS FOR
THE DC/BALTIMORE METROS THURSDAY WITH ADDITIONAL ALERTS LIKELY
FRIDAY AS AIR QUALITY WORSENS.
IN ADDITION TO THE HEAT AND SMOKE/POOR AIR QUALITY WILL BE THE
CONCERN FOR A FEW ISOLATED SHOWERS/STRONG THUNDERSTORMS. THE
ATMOSPHERE LOOKS LESS CAPPED THURSDAY AND FRIDAY FOR CONVECTIVE
DEVELOPMENT. HEIGHT FALLS/PVA WILL BE NEGLIGIBLE AS MOST FORCING FOR
ASCENT WILL BE ASSOCIATED WITH SHORTWAVES IN CYCLONIC FLOW PASSING
TO THE NORTH AND NORTHEAST. HOWEVER, A HALT IN HEIGHT RISES PAIRED
WITH A SLOWLY SOUTHWARD SAGGING COLD FRONT AND POTENTIALLY BAY
BREEZES IN AREAS WHERE LOW-LEVEL FLOW GOES WEAK IN THE VICINITY OF
THE FRONT, MAY BE ENOUGH WHEN COUPLED WITH HEATING TO RESULT IN A
COUPLE OF ISOLATED THUNDERSTORMS. THERE IS FURTHER UNCERTAINTY GIVEN
CONTINUED SMOKE ALOFT, AS THAT COULD HAMPER HEATING AND
INSTABILITY/CONVECTIVE INITIATION.UPSTREAM OVER NE PA INTO NJ AND
THE NYC TRI-STATE AREA FROM EARLIER TODAY MAY OFFER A CLUE AS WE
WILL BE IN A SIMILAR ENVIRONMENT ACROSS THE MD/PA BORDER THURSDAY
AFTERNOON. ANY STORMS THAT MANAGE TO DEVELOP WILL HAVE AMPLE MLCAPE
(2000-3000 J/KG) AND DCAPE (1000-1500 J/KG) TO WORK WITH, AS WELL AS
NOTABLE FLOW IN THE MID AND UPPER LEVELS FOR MID JULY (40-50+ KTS).
IF ANY STORMS MANAGE TO DEVELOP BY LATE AFTERNOON, THEY COULD AT
LEAST BRIEFLY CONGEAL INTO A SMALL CLUSTER AND PROPAGATE SOUTH/
SOUTHEAST TOWARD AND ACROSS THE CHESAPEAKE BAY DURING THE EVENING
HOURS. DAMAGING WINDS WOULD BE THE PRIMARY (CONDITIONAL) RISK, BUT
LARGE HAIL IS ALSO POSSIBLE GIVEN AMPLE CAPE, SHEAR, AND LOW
SEASONABLY LOW WET-BULB ZERO HEIGHTS AROUND 11.5 KFT. ANY STORMS
THAT WE DO SEE WILL HELP SCRUB OUT SOME OF THE SMOKE AND IMPROVE AIR
QUALITY.
KEY MESSAGE 2...THUNDERSTORM CHANCES INCREASE THIS WEEKEND AND COULD
POTENTIALLY LINGER INTO SUNDAY AS A FRONT DROPS INTO THE REGION.
THE SURFACE FRONT WILL DROP FURTHER SOUTHWARD FRIDAY. ADDITIONAL
SMOKE LIKELY MIXES INTO THE REGION. ANY CONVECTION ON FRIDAY WILL
LIKELY BE LIMITED TO THE HIGHER TERRAIN AS THE FRONT WASHES OUT AND
PAIRS WITH OROGRAPHIC LIFT. AGAIN, ANY STORM THAT DOES FORM COULD BE
ON THE STRONG SIDE.
FRIDAY NIGHT, THE AFOREMENTIONED FRONT WILL BEGIN TO LIFT NORTH
AHEAD OF A WAVE OF LOW PRESSURE AND STOUT SHORTWAVE APPROACHING FROM
THE UPPER MIDWEST/GREAT LAKES. INCREASING MLCAPE LATE AT NIGHT WITH
SOME MOISTURE ADVECTION AND MODEST LOW-LEVEL FLOW OVERTOP THE FRONT
MAY RESULT IN A FEW THUNDERSTORMS HEADING INTO EARLY SATURDAY
MORNING, ESPECIALLY EAST OF THE BLUE RIDGE WHERE A BIT RICHER LOW-
LEVEL THETA-E RIDGE LOOKS TO PIVOT THROUGH.
FORCING AND SHEAR WILL BE AMPLE ON SATURDAY, BUT THE AMOUNT OF
INSTABILITY IS IN QUESTION DUE TO POTENTIAL MORNING PRECIP.
SHOULD ENOUGH INSTABILITY DEVELOP, SEVERE WEATHER IS CERTAINLY
POSSIBLE WITH ALL HAZARDS (DAMAGING STRAIGHT-LINE WINDS, LARGE HAIL,
A FEW TORNADOES, AND ISOLATED INSTANCES OF FLASH FLOODING) ON THE
TABLE. THIS ALIGNS WITH CSU/NSSL/CIPS PROBABILITIES WHICH SUGGEST A
5 TO 15 PERCENT PROBABILITIES OF SEVERE WEATHER DURING THE WEEKEND
PERIOD. IF THE FRONT DOES NOT MAKE IT ENTIRELY THROUGH THE AREA,
REPEATED STRONG STORMS WILL BE POSSIBLE ON SUNDAY.
AFTER A BRIEF LULL POSSIBLE ON MONDAY, ANOTHER STRONG WAVE MAY
APPROACH BY THE MIDDLE OF NEXT WEEK.
AVIATION /01Z THURSDAY THROUGH MONDAY/
VFR CONDITIONS WILL LIKELY CONTINUE THROUGH FRIDAY UNDER MOSTLY DRY
CONDITIONS. ONE THING OF NOTE WILL BE SMOKE ALOFT FROM FIRES BURNING
OVER WESTERN ONTARIO. THIS WILL RESULT IN A HAZY APPEARANCE OF THE
SKY THROUGH FRIDAY. VSBY REDUCTIONS OF 5-6 SM ARE POSSIBLE CORRIDOR
THURSDAY AND FRIDAY AFTERNOONS WITH LOWER VSBYS (2-4 SM) THURSDAY
NIGHT INTO FRIDAY, ESPECIALLY NORTH AND EAST OF IAD/DCA AS SMOKE
MIXES SOUTH AND CLOSER TO THE SURFACE BEHIND A WEAK FRONT. WINDS
WILL VARY BETWEEN N/NW AND SW OVER THE NEXT FEW DAYS AS THAT FRONT
SITS NEARBY. A THUNDERSTORM CAN'T BE RULED OUT THURSDAY LATE
AFTERNOON AND EVENING, MAINLY EAST OF THE BLUE RIDGE AND IN NORTHERN
MD BUT CONFIDENCE IS VERY LOW. DID ADD A PROB30 BETWEEN 20-24Z AT
BOTH BWI/MTN WHERE THE CONFIDENCE SEEMS THE HIGHEST FOR STORM
DEVELOPMENT OFF THE BAY BREEZE. CAN'T RULE OUT A THUNDERSTORM NEAR
THE MOUNTAINS FRIDAY AFTERNOON.
PERIODS OF SUB-VFR RESTRICTIONS CAN BE EXPECTED AT TIMES THROUGH THE
WEEKEND DUE TO THUNDERSTORMS. THE GREATEST COVERAGE OF STORMS WILL
LIKELY BE ON SATURDAY POTENTIALLY LINGERING INTO SUNDAY. EXPECT
EARLY MORNING LOW CIGS OR PATCHY FOG WITH AFTERNOON/EVENING
CONVECTION. WINDS WILL REMAIN LIGHT OVERALL WITH CHAOTIC MOTIONS IN
AROUND THUNDERSTORMS.
MARINE
WINDS WILL WAVER BETWEEN N/NW AND SW OVER THE NEXT FEW DAYS AS A
COLD FRONT DANGLES NEAR THE WATERS. DEPENDING ON THE STRENGTH OF THE
FRONT AND HOW FAR NORTH OR SOUTH IT PUSHES, THERE MAY BE AT LEAST
BRIEF/MARGINAL PERIODS OF SCA LEVEL GUSTS, THOUGH THESE CURRENTLY
APPEAR TOO BRIEF WITH CERTAINTY TOO LOW FOR ANY HEADLINES AT THE
MOMENT. A COUPLE OF THUNDERSTORMS CAN'T BE RULED OUT ALONG THE COLD
FRONT THURSDAY LATE AFTERNOON AND EVENING, AND ANYTHING THAT DOES
MANAGE TO FORM COULD PRODUCE RATHER GUSTY WINDS.
MORE WIDESPREAD THUNDERSTORM ACTIVITY AND THE NEED FOR SMWS WILL BE
NEEDED OVER THE WEEKEND AS A COLD FRONT SAGS INTO THE REGION.
SOUTHERLY CHANNELING ALSO RETURNS TO PORTIONS OF THE WATERS SATURDAY
INTO SUNDAY.
CLIMATE
WELL ABOVE NORMAL TEMPERATURES WILL PERSIST THROUGH THURSDAY.
BELOW IS A LIST OF RECORD DAILY HIGH AND WARM LOW TEMPERATURES FOR
JULY 15 (WEDNESDAY) AND JULY 16 (THURSDAY).
=================================================================
JULY 15 RECORD DAILY HIGH/WARM LOW TEMPERATURES
=================================================================
BALTIMORE MD 102 (2024, 1995) 79 (1995, 1936)
WASHINGTON DC 102 (2024) 81 (2024)
STERLING-DULLES AIRPORT VA 99 (2024) 75 (2024)
BALTIMORE (DOWNTOWN) MD 101 (2024) 85 (1988)
ANNAPOLIS MD 101 (1995) 81 (1896)
HAGERSTOWN MD 102 (1954) 78 (2024)
MARTINSBURG WV 107 (1936) 75 (1995)
CHARLOTTESVILLE VA 102 (1954) 76 (1936)
=================================================================
JULY 16 RECORD DAILY HIGH/WARM LOW TEMPERATURES
=================================================================
BALTIMORE MD 104 (2024, 1988) 78 (1879)
WASHINGTON DC 104 (2024, 1988) 84 (1983)
STERLING-DULLES AIRPORT VA 104 (1988) 74 (2013)
BALTIMORE (DOWNTOWN) MD 105 (2024) 85 (2013)
ANNAPOLIS MD 98 (1997, 1900) 79 (2024, 2013, 1955)
HAGERSTOWN MD 104 (1988) 76 (2024)
MARTINSBURG WV 107 (1988) 77 (1983)
CHARLOTTESVILLE VA 102 (1988) 82 (1983)
PERIOD OF RECORD (POR) INFORMATION (RECORDS SINCE):
BALTIMORE MD - JULY 1872
WASHINGTON DC - JANUARY 1872
STERLING - DULLES AIRPORT VA - JANUARY 1960
BALTIMORE (DOWNTOWN) MD - JULY 1950
ANNAPOLIS MD - JANUARY 1894
HAGERSTOWN MD - JANUARY 1899
MARTINSBURG WV - JANUARY 1891
CHARLOTTESVILLE VA - JANUARY 1893
LWX WATCHES/WARNINGS/ADVISORIES
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
DISCUSSION...DHOF/EST
AVIATION...DHOF/EST
MARINE...DHOF/EST
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