210
FXUS61 KPBZ 181803
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
103 PM EST WED FEB 18 2026
WHAT HAS CHANGED
UPDATE ON THE THUNDERSTORM POTENTIAL TOMORROW. WINTER WEATHER
HEADLINES REMAIN LOW OVER THE WEEKEND.
KEY MESSAGES
1) ICE JAM POTENTIAL THROUGHOUT THE WEEK
2) THUNDERSTORM CHANCES INCREASE THURSDAY NIGHT INTO FRIDAY
MORNING
3) SNOW POTENTIAL OVER THE WEEKEND
DISCUSSION
KEY MESSAGE 1...
ABOVE-AVERAGE TEMPERATURES OVER THE PAST 48 HOURS AND CONTINUING
THROUGH FRIDAY WILL CAUSE RIVER ICE TO THAW AND BREAK UP ON MAIN
STREAM AND SMALLER TRIBUTARIES. AREAS WITH SIGNIFICANT BENDS
("HOT SPOTS") SHOULD BE MONITORED FOR ICE JAMS. WHILE RAINFALL
WILL BE MINIMAL IN THE NEXT 24 HOURS, INCREASED WATER FLOW
FRIDAY INTO SATURDAY COULD LEAD TO WATER BACKUP NEAR ANY ICE
JAMS.
KEY MESSAGE 2...
A NEW STORM SYSTEM IS EXPECTED TO DEVELOP OVER THE NORTHERN
GREAT PLAINS EARLY THURSDAY. IT WILL MOVE EAST AND MERGE WITH A
NEARLY STATIONARY LOW-PRESSURE DISTURBANCE OVER THE GREAT LAKES
LATE THURSDAY INTO EARLY FRIDAY.
THE CONVERGENCE OF WARM, MOIST AIR FROM THE SOUTHWEST AND
INCREASING VERTICAL WIND SHEAR TO PROMPT LIFT CREATES A WINDOW
OF THUNDERSTORM DEVELOPMENT BETWEEN 10PM THURSDAY TO 2AM FRIDAY.
DESPITE STRONG LOW-LEVEL SHEAR, OVERALL INSTABILITY IS LIMITED
("LACKLUSTER") DUE TO THE PRESENCE OF WARM AIR HIGHER IN THE
ATMOSPHERE, SUBSIDING THE GROWTH OF DEEP STORMS. THE BEST
POTENTIAL FOR STRONG TO SEVERE STORMS IS WEST OF FORECAST AREA,
NEAR INDIANA AND ILLINOIS, WHERE LOW-LEVEL MOISTURE IS AVAILABLE
TO OVERCOME THE WARM AIR ALOFT. HENCE THE STORM PREDICTION
CENTER (SPC) OVERLAYING A "SLIGHT" RISK FOR THAT NOTED REGION.
STORM CHANCES WILL LIKELY DECREASE BEFORE DAWN ON FRIDAY.
HOWEVER, LINGERING RAIN SHOWERS WILL LIKELY CONTINUE INTO LATE
FRIDAY MORNING BEFORE DRIER AND COOLER CONDITIONS RETURN.
KEY MESSAGE 3...
THE WEATHER PATTERN WILL SHIFT SIGNIFICANTLY THIS WEEKEND WITH A
RIDGE AXIS ADVANCING OVER THE WEST COAST AND A TROUGH ADVANCING
ACROSS THE GREAT LAKES. THIS SETUP WILL LEAD TO A RETURN OF
COOLER CONDITIONS AND THE POTENTIAL OF SNOW SUNDAY INTO MONDAY.
THE CHANCE OF MINOR IMPACTS IS LOW AREA-WIDE (20-30%), MEANING
WINTER HEADLINES ARE NOT EXPECTED. LOCALIZED UPSLOPING OVER THE
WEST VIRGINIA RIDGES MAY BE ENOUGH TO TRIGGER AN ADVISORY.
PROBABILITY OF 3 INCHES OF SNOW IN TUCKER COUNTY IN 24 HOURS IS
40% AT THE MOMENT.
AVIATION /18Z WEDNESDAY THROUGH MONDAY/
KEY MESSAGES...
- MVFR IN EXITING RAIN SHOWERS AND LOW CLOUDS THIS AFTERNOON
- BRIEF IMPROVEMENT WITH SCATTERING THIS EVENING BEFORE
RESTRICTIONS IN CLOUDS AND FOG RETURN TONIGHT
------------------------------------------------------------
CONDITIONS HAVE DEGRADED TO MOSTLY MVFR ACROSS THE BOARD THIS
AFTERNOON IN A WARM ADVECTION REGIME PROVIDING GRADUAL ASCENT
AND LIGHT RAIN SHOWERS. UPSTREAM OBSERVATIONS INDICATE THAT A
BRIEF PERIOD OF IFR CIGS, AND BRIEF VIS, IS ACCOMPANYING THIS
FINAL PUSH OF SHOWERS. HAVE INCLUDED A TEMPO AT ALL SITES SAVE
SAVE MGW AND ZZV WHERE FARTHER DISTANCE FROM THE BULK OF THE
SATURATION SHOULD MAINTAIN MVFR. WE SHOULD SEE THE RAIN MAKE AN
EXIT FROM WEST TO EAST THIS EVENING AND CLEAR OUT OF OUR AREA
BEFORE 00Z AS DRIER AIR FILTERS IN AND SCATTERS OUT CEILINGS
LIKELY RETURNING A BRIEF PERIOD OF VFR AFTER SUNSET.
THIS IMPROVEMENT LOOKS TO BE RATHER SHORT LIVED AS NEAR-
SURFACE MOISTURE RE-MANIFESTS AS LOW STRATUS AND FOG. THE 12Z
HREF HAS COME IN MUCH MORE AGGRESSIVE ON VISIBILITY RESTRICTIONS
OVERNIGHT IN FOG. PROBABILITY FOR <1 KFT CIGS IS 70+% AND EVEN
THE 50TH PERCENTILE VIS IS NOW LESS THAN A MILE ACROSS THE
BOARD. FOG APPEARS MORE LIKELY WITH LIGHT TO CALM WIND ACROSS
MOST OF THE AREA, AND DENSITY WILL BE HIGHEST WHERE THE MOST
RAIN FALLS TODAY, LIKELY FOR FKL/DUJ. ALSO CAN'T ENTIRELY RULE
OUT A FEW WIDELY SCATTERED SHOWERS AND EVEN A THUNDERSTORM
DEVELOPING ALONG A PASSING COLD FRONT AROUND MIDNIGHT TONIGHT AS
WE GET SOME ELEVATED INSTABILITY AHEAD OF THE BOUNDARY.
CONFIDENCE IN THIS IS NOT HIGH AS SOME HI RES MODELS SHOW
DEVELOPMENT AND SOME DON'T, SO HAVE LEFT ANY MENTION OUT OF THE
CURRENT TAFS, BUT THE BEST CHANCE WILL BE AT FKL/DUJ.
WIND HOLDS OUT OF THE SOUTHWEST THIS AFTERNOON AT 5-10 KNOTS
WITH GUST UP TO 20 KNOTS AND RELAXES AFTER SUNSET BECOMING LIGHT
AND VARIABLE OVERNIGHT.
OUTLOOK... LINGERING BR AND FG ISSUES REMAIN POSSIBLE THURSDAY
OVER MOIST GROUND. RAIN AND RESTRICTION CHANCES WILL CONTINUE
INTO THE WEEKEND.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
DISCUSSION...HEFFERAN
AVIATION...MLB
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