101
FXUS61 KBGM 210551
AFDBGM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BINGHAMTON NY
151 AM EDT FRI AUG 21 2026
WHAT HAS CHANGED
RAIN HAS DEVELOPED FARTHER NORTH THAN MODELS SUGGESTED. ADJUSTED
RAINFALL CHANCES AND QPF AMOUNTS THIS AFTERNOON AND EVENING
PORTIONS OF THE SOUTHERN TIER INTO NEPA.
KEY MESSAGES
1) A LOW PRESSURE SYSTEM WILL BRING COOL TEMPERATURES AND RAIN
SHOWERS TO THE AREA THIS AFTERNOON INTO THE EVENING. MOST OF THE
RAIN WILL BE SOUTH OF THE MOHAWK VALLEY. HIGH PRESSURE BUILDS IN
BEHIND THE SYSTEM, BRINGING PLEASANT AND DRY CONDITIONS TO THE
REGION ON FRIDAY
2) A DEEP UPPER LEVEL TROUGH OVER THE EAST COAST THIS WEEKEND WILL
DRIVE PERIODS OF SHOWERS ACROSS THE AREA SATURDAY AND SUNDAY,
LINGERING INTO MONDAY. HIGH PRESSURE WILL MOVE INTO THE REGION
THROUGH MID-WEEK.
DISCUSSION
KEY MESSAGE 1...
A LOW PRESSURE SYSTEM CURRENTLY CENTERED OVER SOUTH CENTRAL PA WILL
BE THE MAIN WEATHER FEATURE FOR THE DAY. RAIN HAS DEVELOPED FARTHER
NORTH THAN GUIDANCE HAS BEEN SUGGESTING OVER THE PAST FEW RUNS. RAIN
AMOUNTS UP TO 0.25 INCHES CAN BE EXPECTED OVER THE SOUTHERN TIER
WITH LIGHTER RAIN AMOUNTS AS YOU PROGRESS TO THE NORTH. ONLY A TRACE
IS EXPECTED ACROSS THE WYOMING VALLEY AND TO THE NORTH.
THE HEAVIEST RAIN IS NEAR THE CENTER OF THE LOW, WITH DIVERGENCE ON
THE NW PORTION OF THE LOW DRIVING SOME MODERATE RAIN SHOWERS. THIS
WILL SLOWLY TRACK EASTWARD AS THE AFTERNOON PROGRESSES. UPPER LEVEL
DYNAMICS LOOK TO INCREASE AS THE AFTERNOON PROGRESSES. BY MID TO
LATE AFTERNOON, A STRENGTHENING LEFT ENTRANCE REGION OF A JET STREAK
IS EXPECTED TO BE OVER THE CATSKILLS INTO POCONOS. THIS WILL HELP
DEEPEN THE SURFACE LOW AND BRING PERIODS OF MODERATE RAINFALL OVER
THE WYOMING VALLEY INTO PIKE COUNTY. GUIDANCE IS ALSO SUGGESTING
THAT THIS UPPER LEVEL STRENGTHENING WILL SHUNT ENERGY FROM THE
CURRENT LOW TO A NEW AND DEEPER SURFACE LOW ALONG THE NJ COASTLINE.
THIS WOULD REDUCE RAINFALL POTENTIAL ACROSS THE AFOREMENTIONED AREAS
DURING THE LATE AFTERNOON AND EVENING HOURS. CURRENTLY, ABOUT 0.75-
1.10 INCHES ARE FORECAST TO FALL ACROSS THE WYOMING VALLEY INTO PIKE
COUNTY THIS AFTERNOON INTO THE EVENING HOURS. LOOKING AT FLASH FLOOD
CHANCES, CONFIDENCE IN WIDESPREAD FLASH FLOODING IS VERY LOW. FLASH
FLOOD GUIDANCE FOR NEPA IS PRETTY HIGH GIVEN THE RECENT DRY WEATHER,
WITH 1HR GUIDANCE HOVERING ABOVE 2 INCHES FOR MOST OF THE AREA. WE
ARE NOT EXPECTING WIDESPREAD CONVECTION SO THE CHANCE FOR A PERIOD
OF 2+IN/HR IS VERY LOW. THE TRACK OF THE LOW SHOULD KEEP OUR REGION
TO THE NORTH OF THE WARM SECTOR AND BRING MOSTLY STRATIFORM
RAIN. A DEFORMATION BAND COULD DEVELOP AND BRING AN INCH TO
PORTIONS OF NEPA OVER A COUPLE HOUR PERIOD, BUT RATES ARE NOT
EXPECTED TO BE HIGH ENOUGH FOR FLASH FLOODING. GIVEN THE
PROLONGED RAIN PERIOD, THERE COULD BE PONDING ON ROADWAYS OR
SOME MINOR URBAN FLOODING ACROSS AREAS WITH POOR DRAINAGE.
RAIN IS EXPECTED TO EXIT THE AREA BY 9PM AS THE SECOND LOW DEVELOPS
OVER NJ. HIGH PRESSURE WILL DEVELOP BEHIND THIS DEPARTING SYSTEM.
THE WET GROUND COMBINED WITH LIGHT TO CALM WINDS AND CLEARING SKIES
WILL ALLOW FOR WIDESPREAD PATCHY FOG WITH AREAS OF DENSE FOG,
ESPECIALLY IN THE VALLEYS. FOG SHOULD BURN OFF BY MID-MORNING WITH A
PLEASANT FRIDAY EXPECTED. MOSTLY SUNNY SKIES AND NW FLOW WILL KEEP
TEMPERATURES IN THE MID 70S TO LOW 80S.
KEY MESSAGE 2...
THE HIGH PRESSURE WILL NOT STICK AROUND FOR LONG AS AN UPPER LEVEL
TROUGH DIGGING INTO THE EASTERN US FROM CANADA WILL BE THE NEXT
FEATURE DRIVING WEATHER CONDITIONS THIS WEEKEND.
THE SURFACE HIGH OVER THE AREA FRIDAY WILL SLIDE TO THE NE, BUT IS
EXPECTED TO HAVE A LOBE EXTEND BACK TO THE SW AND REMAIN OVER THE
CWA THROUGH SATURDAY MORNING. 925MB AND 850MB HEIGHTS ALSO REMAIN
SOMEWHAT CONSISTENT THROUGH SATURDAY MORNING. THESE FACTORS
SHOULD HELP LIMIT RAINFALL CHANCES OVER THE REGION. A SURFACE
LOW IS EXPECTED TO DEVELOP OVER THE MID-ATLANTIC AND RACE NORTH
SATURDAY AFTERNOON WHILE ANOTHER SURFACE LOW DEVELOPS OVER THE
EASTERN GREAT LAKES AS THE UPPER TROUGH CONTINUES TO AMPLIFY
ACROSS THE EASTERN US. GUIDANCE REMAINS SOMEWHAT UNSURE AS TO
HOW THESE SYSTEMS WILL DEVELOP AND INTERACT WITH THE HIGH
PRESSURE OVER NE NEW ENGLAND CONTINUING TO EXERT ITS INFLUENCE
OVER THE REGION THROUGH THE DAY. IT IS TRENDING TOWARD THE MID-
ATLANTIC LOW TRACKING TO OUR EAST WITH LIGHT RAIN ACROSS THE
POCONOS AND CATSKILLS, FOLLOWED BY MORE WIDESPREAD RAIN SHOWERS
ACROSS THE AREA SUNDAY AS THE GREAT LAKES LOW SLOWLY MOVES TO
THE NE, WEST AND NORTH OF THE CWA. THE UPPER TROUGH IS PROGGED
TO BEGIN TO TILT NEGATIVELY SUNDAY EVENING, HELPING TO PUSH THE
SURFACE LOW OUT OF THE AREA TO THE NNE. MUCH OF THE RAIN SHOULD
GO WITH IT, BUT A STRONG CUTOFF LOW AT 500MB IS FORECAST TO DIVE
INTO THE AREA SUNDAY NIGHT THRU MONDAY. THIS SHOULD ALLOW FOR
LINGERING SHOWERS ON MONDAY MOSTLY NORTH OF THE SOUTHERN TIER.
HIGH PRESSURE RETURNS TUESDAY INTO THURSDAY BEFORE THE NEXT
WEATHER MAKER MOVES INTO THE REGION. TEMPERATURES DURING THIS
PERIOD SHOULD BE AVERAGE TO SLIGHTLY BELOW AVERAGE.
AVIATION /06Z FRIDAY THROUGH TUESDAY/
RAINFALL EARLIER TODAY ACROSS THE SOUTHERN TIER AND NORTHEAST PA
HAS LED TO WIDESPREAD FOG DEVELOPMENT ACROSS MUCH OF THE
REGION. RAIN DID NOT REACH SYR/RME, SO WIDESPREAD FOG IS NOT
ANTICIPATED AT THESE SITES. HOWEVER, SOME POTENTIAL REMAINS, SO
TEMPO GROUPS WERE INCLUDED. ELM AND ITH FOGGED IN QUICKLY THIS
EVENING, WITH LIFR CEILING AND VISIBILITIES EXPECTED TO PERSIST
THROUGH AROUND 14Z. BGM MAY INITIALLY REMAIN ABOVE THE VALLEY
FOG, THOUGH IT SHOULD EVENTUALLY WORK ITS WAY UP TO THE
TERMINAL. FOG ALSO HAS A GOOD CHANCE OF REACHING AVP, THOUGH
CONFIDENCE IS LOWER ON WHETHER RESTRICTIONS WILL BE PRIMARILY TO
VISIBILITY OR CEILINGS. THEREFORE AN IFR TEMPO GROUP WAS USED
AT THIS TIME. ONCE FOG DISSIPATES AFTER 14Z THIS MORNING, VFR
CONDITIONS ARE EXPECTED FOR THE REMAINDER OF THE TAF PERIOD.
OUTLOOK...
FRIDAY THROUGH SATURDAY MORNING...MAINLY VFR CONDITIONS; AREAS
OF MORNING FOG, ESPECIALLY NEAR KELM.
SATURDAY AFTERNOON THROUGH SUNDAY...SHOWERS AND POTENTIALLY
THUNDERSTORMS WITH ASSOCIATED RESTRICTIONS.
MONDAY...SCATTERED SHOWERS AT THE CENTRAL NY TERMINALS WITH
ASSOCIATED RESTRICTIONS POSSIBLE.
TUESDAY...MAINLY VFR.
BGM WATCHES/WARNINGS/ADVISORIES
PA...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR PAZ038>040-
043-044-047.
NY...DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR NYZ022>025-
036-044>046-055>057.
DISCUSSION...AJG/JTC
AVIATION...AJG/ES
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