922
FXUS61 KRLX 071052
AFDRLX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
652 AM EDT THU JUL 7 2022
SYNOPSIS
A SHIFTY FRONT KEEPS SHOWERS AND THUNDERSTORMS MEANDERING IN
AND OUT OF THE AREA, WITH A RELATIVE LULL TODAY AND TONIGHT, AN
UPTICK ON FRIDAY, AND THEN GRADUAL IMPROVEMENT THIS WEEKEND.
NEAR TERM /THROUGH TONIGHT/
AS OF 650 AM THURSDAY...
LOW LEVEL STRATUS HAS STRETCHED DOWN TO THE SURFACE IN SOME
AREAS ALONG THE OHIO RIVER VALLEY THIS MORNING, WHERE VSBYS HAVE
FALLEN BENEATH A HALF A MILE. OPTED FOR AN SPS FOR THE NEXT TWO
HOURS TO DENOTE THIS FOR THE MORNING COMMUTE.
REFURBISHED POPS A TAD IN NORTHEAST WV BASED ON RADAR TRENDS
THIS MORNING WHERE A FEW SHOWERS CONTINUE TO PROSPER NEAR UPSHUR
AND RANDOLPH COUNTIES. NEARING THE END OF THESE SHOWERS FOR THE
MORNING, ALLOWING FOR A BRIEF REPRIEVE BEFORE ISOLATED
CONVECTION SPROUTS IN THE AFTERNOON.
AS OF 355 AM THURSDAY...
UPPER RIDGING OVER THE MISSISSIPPI VALLEY MAINTAINS DOMINANCE
TODAY, WITH MID-LEVEL SHORTWAVES RIDING ALONG THE NORTHWEST
FLOW OF THIS FEATURE INTO THE OHIO VALLEY AND DOWN INTO THE
CAROLINAS. AT THE SURFACE, A COLD FRONT IS ANALYZED DIRECTLY
OVERHEAD THIS MORNING AND IS PROJECTED TO SLUGGISHLY SHIFT
SOUTHWARD HEADING INTO THE END OF THE WORK WEEK.
WITH THE FRONT FURTHER SOUTH THAN PAST FEW DAYS, THE BULK OF
CONVECTION WILL BE CONCENTRATED OUTSIDE OF THE CENTRAL
APPALACHIANS. HIGHER RESOLUTION MODEL GUIDANCE DEPICTS
CONVECTION FIRING UP TODAY SOUTH OF THE FORECAST AREA WHERE
STRONGER FORCING WILL BE PRESENT. HOWEVER, A FEW DIURNALLY
DRIVEN SHOWERS AND STORMS MAY PERUSE THE HIGHER TERRAIN BEFORE
SUNSET. FLOODING AND SEVERE CONCERNS WILL BE MUCH LOWER IN
COMPARISON TO THE ACTIVE FIRST HALF OF THE WEEK WE EXPERIENCED.
SKIES WILL PARTIALLY CLEAR ACROSS THE NORTH BY LATE IN THE
AFTERNOON AND EVENING, WITH ANVIL BLOW OFF FROM STORMS
SPROUTING WITHIN THE TENNESSEE VALLEY PROCEEDING TO OOZE INTO
THE SOUTHERN COALFIELDS LATE TONIGHT.
WHILE NOT MUCH OF A COOLER AIRMASS SETTLES IN BEHIND THE COLD
FRONT, TEMPERATURES WILL NESTLE CLOSER TO THEIR CLIMATOLOGICAL
NORM THIS AFTERNOON AND OVERNIGHT. MUGGY CONDITIONS CONTINUE
THROUGH THE PERIOD, IN RESPONSE TO LOW TO MID 70 DEW POINTS
STILL FESTERING OVERHEAD, BUT HEAT INDEX VALUES REMAIN BELOW
ADVISORY CRITERIA.
SHORT TERM /FRIDAY THROUGH SUNDAY/
AS OF 505 AM THURSDAY...
THE NAM12 APPEARS TO BE QUITE THE OUTLIER AND, AT FIRST GLANCE,
WITH A LOW PRESSURE SYSTEM ROLLING THROUGH THE AREA FRIDAY
THROUGH SATURDAY, WITH A SLOWER AND MUCH FARTHER NORTH TRACK
THAT WOULD STILL HAVE THE AREA IN THE WARM SECTOR THROUGH
SATURDAY MORNING. HOWEVER, THE OTHER MODELS ALL SHOW THE SHIFTY
FRONT ASSOCIATED WITH THIS SYSTEM BUCKLING HITHER AND TITHER,
AND TAKING THE BETTER PART OF THE DAY SATURDAY TO GET THE FRONT
THROUGH THE AREA. THE NAM12 WAS ALSO THE FIRST MODEL TO PICK UP
ON SHIFTING THE CONVECTIVELY ACTIVE AXIS LARGELY SOUTH OF THE
AREA TODAY AND TONIGHT.
FRIDAY AFTERNOON AND EVENING IS LIKELY TO BE THE MOST ACTIVE
PERIOD GIVEN DIURNAL HEATING, WITH A WAVY FRONT AND MID/UPPER
LEVEL SHORT WAVE TROUGH COMING INTO THE AREA FRIDAY EVENING.
THE SYSTEM WILL BE ABLE TO TAKE ADVANTAGE OF THE VERY WARM,
HUMID AND UNSTABLE AIR MASS SOUTH OF THE FRONT FOR A
CONVECTIVELY ACTIVE AFTERNOON AND EVENING THERE. HOWEVER, WITH
RECENT CONVECTION WORKING THE ATMOSPHERE OVER THE PAST COUPLE OF
DAYS, MODELS ARE GENERALLY ONLY FORECASTING AROUND 1-2 KJ/KG
CAPE FRIDAY AFTERNOON SOUTH OF THE FRONT, TO GO ALONG WITH 30-35
KTS BULK SHEAR, THE HIGHER SHEAR NORTH OF THE FRONT AND
INSTABILITY.
PW VALUES UP AROUND 2 INCHES WITH AREAS OF FORCED ASCENT
ASSOCIATED WITH THE SYSTEM COMING IN NEAR AND JUST AFTER PEAK
HEATING, SHOULD LEAD TO CONVECTION WITH HIGH AREA COVERAGE ALONG
AND EITHER SIDE OF THE FRONT, LEADING TO COPIOUS RAINFALL THAT
COULD BECOME EXCESSIVE. THERE ARE SEVERAL REGIONS WITHIN THE
FORECAST AREA THAT HAVE RECEIVED HEAVY RAINFALL OVER THE PAST
COUPLE OF DAYS, AND ARE VULNERABLE WITH LOW FLASH FLOOD GUIDANCE
VALUES AS A RESULT, DOWN IN THE 1-1.5 INCH RANGE PER 3 HOURS
EAST OF A LONGITUDE LINE RUNNING THROUGH ABOUT HTS.
THESE THREATS ARE DEPICTED WITH A MARGINAL RISK FOR EXCESSIVE
RAINFALL ACROSS SOUTHERN PORTIONS OF THE AREA, AND A SLIGHT
RISK FOR EXCESSIVE RAINFALL ACROSS MUCH OF THE AREA, DURING THE
FRIDAY THROUGH FRIDAY NIGHT PERIOD. THE BEST CHANCE TO REALIZE
THESE THREATS WOULD BE DURING THE AFTERNOON AND EVENING HOURS,
EXCEPT DEEPER INTO THE NIGHT ON THE EXCESSIVE RAINFALL THREAT.
WHILE THE MID/UPPER LEVEL SHORT WAVE TROUGH SHIFTS EAST OF THE
AREA SATURDAY, THE WAVY FRONT BUCKLES, WITH AN INVERTED TROUGH
EXTENDING NORTH OF IT THROUGH THE MIDDLE OHIO VALLEY. WITH WEAK
MID LEVEL RIPPLES, AND INSTABILITY, ALBEIT WEAK, PROGGED AS FAR
WEST AS THIS INVERTED TROUGH, SHOWERS APPEAR LIKELY IN AND NEAR
THE MOUNTAINS, WITH A GRADUALLY DECREASING CHANCE WEST, AND
THUNDERSTORMS ALSO POSSIBLE THERE AND EVEN BACK INTO THE MIDDLE
OHIO VALLEY AS WELL. THIS FORECAST IS NOT ALL THAT MUCH OF A FAR
CRY FROM THE NAM12 SOLUTION FOR SATURDAY, ALTHOUGH LESS
IMPACTFUL.
THIS IS REFLECTED VIA A GENERAL THUNDER OUTLOOK THROUGHOUT THE
AREA SATURDAY, LIKELY FOR THE AFTERNOON INTO THE EVENING HOURS,
WITH A MARGINAL RISK JUST TO THE SOUTH, BUT A MARGINAL RISK FOR
EXCESSIVE RAINFALL FOR SOUTHEAST PORTIONS OF THE FORECAST AREA.
THE WAVY FRONT SHIFTS FARTHER SOUTH ON SUNDAY, BUT WITH AN
INVERTED TROUGH STILL OVER THE MIDDLE OHIO VALLEY, ALONG WITH
AFTERNOON INSTABILITY. SHOWERS AND AFTERNOON THUNDERSTORMS CAN
STILL OCCUR THAT FAR WEST ON SUNDAY.
CENTRAL GUIDANCE SHOWS HIGHS STILL UP AROUND NORMAL OR EVEN A
BIT HIGHER FOR FRIDAY, AND THEN A LITTLE BELOW NORMAL FOR THE
WEEKEND. FRIDAY NIGHT WILL STILL BE WARM AND A BIT MUGGY,
ESPECIALLY SOUTHEAST OF THE OHIO RIVER, AND THEN SATURDAY NIGHT
WILL BE A BIT COOLER, NEAR NORMAL FOR LOWS AND A BIT MORE
COMFORTABLE.
LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/
AS OF 505 AM THURSDAY...
A HIGH AMPLITUDE UPPER LEVEL LONG WAVE PATTERN, PARTICULARLY
FOR MID SUMMER, BUILDS THIS PERIOD, AS A LONG WAVE RIDGE BUILDS
OVER THE ROCKIES AND PLAINS, AND A LONG WAVE TROUGH DEEPENS
OVER THE ASTERN U.S.
AFTER HIGH PRESSURE BRINGS A DRY START TO THE WORK WEEK, A SHORT
WAVE TROUGH CONTRIBUTING TO CARVING OUT THE DEEPER LONG WAVE
TROUGH, PUSHES A COLD FRONT THROUGH THE AREA LATE WEDNESDAY OR
WEDNESDAY NIGHT, WITH SHOWERS AND THUNDERSTORMS POSSIBLE LATE
TUESDAY THROUGH WEDNESDAY. THIS FRONT WILL KEEP ON MOVING,
ALLOWING THE RETURN OF DRY WEATHER WEDNESDAY NIGHT. HOWEVER,
THE PATTERN SUPPORTS ANOTHER COLD FRONT ARRIVING SHORTLY
THEREAFTER.
CENTRAL GUIDANCE REFLECTS HIGH TEMPERATURES A LITTLE ABOVE
NORMAL EARLY IN THE WORK WEEK, FALLING TO NEAR NORMAL LATE. LOWS
WILL BE AT OR A LITTLE BELOW NORMAL, EXCEPT NEAR TO A LITTLE
ABOVE NORMAL WEDNESDAY MORNING.
AVIATION /12Z THURSDAY THROUGH MONDAY/
AS OF 650 AM THURSDAY...
A COMBINATION OF FOG AND LOW LEVEL STRATUS HAS SQUANDERED FLIGHT
CONDITIONS AROUND THE AREA THIS MORNING AS A COLD FRONT DRAPES
ITSELF OVERHEAD. MVFR CEILINGS MAY CONTINUE TO PLAGUE THE REGION
BEYOND THE FOG EROSION AS LOW LEVEL MOISTURE REMAINS PREVALENT
IN RESPONSE TO THE NEARBY FRONTAL BOUNDARY. SHOULD BEGIN TO
BRANCH OUT THIS AFTERNOON WITH THE HELP OF DAYTIME MIXING.
THE FRONT WILL SLUGGISHLY SHIFT SOUTHWARD TODAY, WHICH ALSO
SHIFTS THE MAIN CONCENTRATION OF CONVECTION DOWN INTO VIRGINIA
AND THE CAROLINAS. A FEW ISOLATED SHOWERS AND STORMS MAY SPROUT
IN THE CENTRAL LOWLANDS AND EAST ALONG THE HIGHER TERRAIN, BUT
COVERAGE WILL BE LIMITED AND COULD MISS ALL THE TAF SITES
ENTIRELY TODAY. OPTED TO INCLUDE VCSH/VCTS WHERE GUIDANCE PEGS
THE BEST POTENTIAL FOR PRECIP AT THE TIME OF THIS ISSUANCE.
WINDS ONCE AGAIN SETTLE TO CALM AND VARIABLE LEVELS THIS
EVENING. COUPLED WITH THE PLETHORA OF LLVL MOISTURE HANGING
ABOUT, THERE WILL ONCE AGAIN BE A STRONG SIGNAL FOR FOG AND/OR
EARLY MORNING STRATUS AT MOST TERMINALS FRIDAY MORNING.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF DEVELOPING SHOWERS AND STORMS
MAY VARY THIS AFTERNOON. INTENSITY OF FOG AND/OR LOW LEVEL
STRATUS MAY VARY OVERNIGHT INTO FRIDAY MORNING.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
EDT 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY M M M L L H H H M H H H
HTS CONSISTENCY H H M H H H H H M H H H
BKW CONSISTENCY M M M M H H H H H H H H
EKN CONSISTENCY M M H H H H H H H M M H
PKB CONSISTENCY H H H M L H M M H H H H
CKB CONSISTENCY H H H H H M H H H H H H
AFTER 12Z FRIDAY...
LOCALIZED IFR CONDITIONS ARE POSSIBLE IN MODERATE TO HEAVY
SHOWERS AND THUNDERSTORMS THROUGH FRIDAY.
RLX WATCHES/WARNINGS/ADVISORIES
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
SYNOPSIS...TRM/MEK
NEAR TERM...MEK
SHORT TERM...TRM
LONG TERM...TRM
AVIATION...MEK
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page