Area Forecast Discussion
Issued by NWS Charleston, WV

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KRLX 301434
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
1034 AM EDT SAT AUG 30 2014

.SYNOPSIS...
TURNING HOT AND MORE HUMID SATURDAY IN DEEP SOUTHWEST FLOW.
MOISTURE INCREASES IN THAT FLOW...WITH AN UPPER LEVEL DISTURBANCES
CROSSINGS THROUGH MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
SENT A QUICK UPDATE TO ADJUST SKY COVER POPULATING MOSTLY CLEAR
SKIES ACROSS THE AREA. UPPER TO MID LEVEL CLOUDS WILL START
ADVECTING TO THE AREA THIS AFTERNOON AHEAD OF AN UPCOMING FRONTAL
SYSTEM AND UPPER LEVEL DISTURBANCE. REST OF FORECAST REMAINS
REPRESENTATIVE.

PREVIOUS DISCUSSION BELOW...
UPDATE...
ASIDE FROM ADJUSTMENTS TO THE CLOUD COVER GRIDS...NO CHANGES TO
THE FORECAST THIS MORNING.

PREVIOUS DISCUSSION...
WITH THE UPPER LEVEL HIGH OVER THE SOUTHEAST COAST DRIFTING TO THE
EAST...WILL BE GETTING INTO A MORE ACTIVE PATTERN INTO THE WEEKEND
WITH SOUTHWEST FLOW ALOFT TAKING HOLD.

HAVE TWO MECHANISMS DRIVING THE WEATHER INTO TONIGHT. THE FIRST IS
AN EXTENSIVE FRONTAL BOUNDARY PUSHING INTO THE MIDDLE OHIO VALLEY.
GIVEN THE STEERING FLOW...PROGRESSION TO THE EAST WILL BE SLOW. THE
SECOND PORTION IS THE UPPER LEVEL TROUGH AXIS EMBEDDED IN THE FLOW
ALOFT. SHOULD PUSH INTO THE TUG FORK VALLEY AROUND 03Z OR SO AND
WILL MARK THE BEGINNING OF THE LIKELY POPS. IN THE END...THIS WILL
MARK THE FIRST WAVE OF A SOMEWHAT EXTENDED WET PERIOD.

INSTABILITY SUFFICIENT FOR THUNDER IS NOT ALL THAT IMPRESSIVE...SO
WILL NOT BLANKET THE POPS WITH THUNDER. RAN THE THUNDER CHANCES
BASED ON NAM CAPE...BUMPING THE THRESHOLD UP A BIT GIVEN THE HIGH
DEWPOINT BIAS OF THE MODEL. PWAT VALUES STILL OVER 1.50 INCHES. NOT
SURPRISING BY ANY STRETCH GIVEN THE LONGWAVE PATTERN.

AS WE CONTINUE TO SEE THAT THE COOLER LATE JULY AND VERY WARM AND
HUMID LATE AUGUST HAVE FLIP FLOPPED ROLES...HAVE ANOTHER DAY WHERE
90 DEGREES OVER THE LOWLANDS WILL BE HIT HERE AND THERE. PROBABLY
WILL NOT BE TOPPED BY MUCH.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
THERE IS MUCH BETTER AGREEMENT WITH THE MODELS IN HANDLING AT LEAST
ONE OF THE TWO MAIN SYSTEMS AFFECTING OUR AREA FOR THE HOLIDAY
WEEKEND. IN GENERAL...LOOKS LIKE AN UNSETTLED PERIOD...ESPECIALLY
SUNDAY.

FIRST SYSTEM CONTINUES TO BE THE UPPER LOW NEAR THE TEXAS COAST THAT
WILL BE PULLED UP AHEAD OF A NORTHERN STREAM UPPER TROUGH SLOWLY
TRAVERSING THE PLAINS STATES. THIS SYSTEM WILL CARRY TROPICAL LIKE
MOISTURE WITH PWS ABOVE 2 INCHES AS IT LIFTS NORTHEAST ACROSS THE
OHIO VALLEY SUNDAY AND SUNDAY EVENING. BEST MODEL CONSENSUS ON THE
TRACK INDICATES THE NORTHWEST HALF OF OUR AREA LOOKS TO SEE THE MOST
AMOUNT OF RAIN FROM THIS SYSTEM...BUT ALL WILL LIKELY SEE A GOOD
SLUG OF RAIN. USUALLY WITH A SYSTEM LIKE THIS...THERE WILL BE
WIDESPREAD SHOWERS WITH LESS EMPHASIS ON THUNDER. THUS...WHILE CAT
POPS ARE ON ORDER FOR SUNDAY...WILL PUT EMBEDDED THUNDER IN THE
CHANCE OR SCATTERED CATEGORY. IF THERE WILL BE MORE ORGANIZED
THUNDERSTORMS...THERE WILL BE INCREASED POTENTIAL FOR WATER PROBLEMS.
HOWEVER...UNCERTAINTY AT THIS POINT KEEPS MENTION OF POTENTIAL WATER
PROBLEMS IN THE HAZARDOUS WEATHER PRODUCT. THE SYSTEM EXITS SUNDAY
EVENING...CARRYING THE TROPICAL LIKE MOISTURE AND RAIN SHIELD WITH
IT. THIS LEAVES SUNDAY NIGHT AND MONDAY IN BETWEEN SYSTEMS...BUT
WITH PWS STILL NEAR 1.5 INCHES...WILL KEEP SMALLER POPS IN MOST
PLACES...BEST CHANCE MONDAY AFTERNOON WITH HEATING.

ANOTHER UPPER TROUGH APPROACHES TUESDAY...THIS TIME DRAGGING A COOL
FRONT WITH IT. LOOK FOR AN INCREASE IN SHOWERS AND THUNDERSTORMS
AHEAD OF THIS FEATURE LATER MONDAY NIGHT AND ESPECIALLY TUESDAY.
MODEL TIMING DIFFERS ON THIS ONE...SO WILL COMPROMISE WHICH LEADS TO
TUESDAY BEING THE BEST TIME FOR SHOWERS.

IT WILL BE A WARM AND QUITE HUMID PERIOD. CLOUDS AND WIDESPREAD
SHOWERS WILL HOLD TEMPERATURES WELL DOWN IN THE LOWER 80S SUNDAY.
THEY WILL REBOUND WELL INTO THE 80S MONDAY WITH LESS CLOUDS AND
SHOWERS. WILL KEEP TEMPS TUESDAY SIMILAR TO MONDAY AS THERE MAY BE
SOME EARLY SUNSHINE TO BOOST TEMPERATURES. WARM AND MUGGY AT
NIGHT.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
LONG TERM PERIOD CAN GENERALLY BE CHARACTERIZED BY ZONAL FLOW ALOFT.
LEANED WPC FOR THE MOST PART WITH A FEW TWEAKS HERE AND THERE. WARM
AND MUGGY CONDITIONS WILL CONTINUE FOR THE MOST PART WITH PERIODIC
DISTURBANCES AND SUBSEQUENT MAINLY DIURNALLY-DRIVEN PRECIP CHANCES.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
VFR THROUGH THE DAY WITH GENERALLY INCREASING CLOUD COVER HEADING
INTO THE EVENING AND TONIGHT. BEST CHANCES FOR SHOWERS OR AN
EMBEDDED STORM OR TWO WILL BE AFTER 03Z SUNDAY. SHRA/VCTS IS
DEFINITELY A BETTER PLAY THAN TSRA...ESPECIALLY GIVEN THE TIME OF
DAY THAT THE CONVECTION IS EXPECTED TO BEGIN. BKW TO HTS LINE MAY
SEE SOME DEVELOPMENT ANY TIME AFTER 00Z SUNDAY HOWEVER. TIMING IN
TAFS IS BASED ON THE TIMING OF THE HIGHER POPS.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SUNDAY...

FORECAST CONFIDENCE: MEDIUM TO HIGH.

ALTERNATE SCENARIOS: TIMING OF SHRA TONIGHT MAY VARY BY AN HOUR OR
TWO.

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       14   15   16   17   18   19   20   21   22   23   00   01
EDT 1HRLY       10   11   12   13   14   15   16   17   18   19   20   21
CRW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
HTS CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
BKW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
EKN CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
PKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H

AFTER 12Z SUNDAY...
IFR POSSIBLE IN SHOWERS/STORMS SUNDAY...AND THEN IN DENSE EARLY
MORNING VALLEY FOG EARLY NEXT WEEK.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...JMV/26
NEAR TERM...ARJ/26
SHORT TERM...JMV
LONG TERM...50
AVIATION...26








USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.