Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/30/14
AREA FORECAST DISCUSSION
NWS PUEBLO CO
325 PM MDT WED MAY 28 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 325 PM MDT WED MAY 28 2014
CURRENTLY...
SHOWERS NOTED MAINLY OVER THE HIGHER TRRN...ESPECIALLY ACROSS THE SW
MTNS AND WETS AND S SANGRES. FLOW ALOFT IS WEAK SO SHOWERS MOVING
VERY SLOWLY. OTHERWISE IT WAS QUITE WARM WITH TEMPS IN THE 80S TO 90
ACROSS THE PLAINS...70 TO L80S VALLEYS...AND 50S AND 60S MTNS.
REST OF TODAY AND TONITE...
MAIN CHANGE I MADE TO THE FCST WAS TO INCLUDE SOME LOW END POPS TO N
EL PASO COUNTY AND TO THE SAN LUIS VALLEY FOR THE REST OF THIS
AFTERNOON AND EARLY EVENING. HRRR INDICATING A FEW SHOWERS WILL MOVE
OUT A LITTLE FARTHER ONTO THE PLAINS.
DISTURBANCE OFFSHORE OF S CALIF COAST IS BRINGING IN SOME HIGHER
LEVEL MOISTURE TO THE SW...AND THESE CLOUDS SHOULD MOVE OVER THE
REGION STARTING LATER THIS EVENING.
TOMORROW(THURSDAY)...
SHOULD SEE AN UPTICK IN HIGH CLOUDS AND SHOWERS OVER THE REGION
TOMORROW...WITH A BETTER CHANCE OF SHOWERS MOVING A BIT FARTHER ONTO
THE PLAINS AS FLOW ALOFT SHIFTS TO MORE SW ALOFT...ESPECIALLY OVER
THE WESTERN SECTIONS OF THE PLAINS. FAR EASTERN PLAINS SHOULD REMAIN
DRY THROUGH LATE TOMORROW AFTERNOON. MAX TEMPS TOMORROW SHOULD BE
ABOUT SIMILAR TO TODAYS HIGHS. /HODANISH
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 325 PM MDT WED MAY 28 2014
PRIMARY METEOROLOGICAL ISSUES DURING THE LONGER TERM APPEAR TO BE
TEMPERATURES AND POPS...WITH ATTENDANT HEAVY RAIN/SEVERE THREAT
AT TIMES DURING PERIODS OF DEEPER ATMOSPHERIC MOISTURE
INTRUSIONS.
INITIALLY...RECENT LONGER TERM COMPUTER SIMULATIONS AND FORECAST
MODEL SOUNDINGS SUGGEST THAT A SOMEWHAT ACTIVE METEOROLOGICAL
PATTERN SHOULD BE NOTED AT TIMES OVER THE FORECAST DISTRICT FROM
THURSDAY EVENING INTO SATURDAY AS UPPER ENERGY ROTATING AROUND
UPPER LOW OVER THE PACIFIC NORTHWEST/INTER-MOUNTAIN REGION
INTERACTS WITH ADEQUATE ATMOSPHERIC MOISTURE VALUES. WFO PUEBLO
WILL NEED TO MONITOR FOR STRONG STORMS AND LOCALLY HEAVY
RAIN(ESPECIALLY OVER/NEAR AREA BURN SCARS) DURING THIS
TIME-FRAME.
SATURDAY NIGHT INTO SUNDAY APPEARS TO BE A TRANSITION DAY TO
DRIER CONDITIONS AS UPPER DISTURBANCE MOVING INTO/ACROSS MONTANA
ALLOWS A DRIER AIRMASS TO DEVELOP OVER THE MAJORITY OF THE CWFA.
FORECAST DISTRICT SHOULD CONTINUE TO NOTICE BASICALLY DRY
CONDITIONS INTO TUESDAY AS TRANSITORY UPPER ZONAL TO UPPER
RIDGING PATTERN IMPACTS THE FORECAST DISTRICT.
A RETURN TO A MORE UNSETTLED METEOROLOGICAL REGIME SHOULD THEN
DEVELOP FROM LATER TUESDAY INTO AT LEAST NEXT WEDNESDAY AS DEEPER
ATMOSPHERIC MOISTURE...NORTHERLY SURGE OVER EASTERN SECTIONS AND
UPPER DISTURBANCES IMPACT SOUTHERN COLORADO.
LATEST COMPUTER SIMULATIONS SUGGEST THAT THE SEVERE WEATHER
THREAT MAY BE INCREASING BY NEXT WEDNESDAY(ESPECIALLY EASTERN
SECTIONS) AS MEAN LAYER SHEAR...ATMOSPHERIC MOISTURE AND
INSTABILITIES ALL BECOME MORE FAVORABLE.
FINALLY...ABOVE CLIMATOLOGICAL LATE MAY/EARLY JUNE TEMPERATURES
ARE ANTICIPATED DURING THE LONGER TERM WITH THE WEEKEND EXPECTED
TO EXPERIENCE THE WARMEST CONDITIONS...WHILE BY MID-WEEK NEXT
WEEK TEMPERATURES DROP TO NEAR SEASONAL AVERAGES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 325 PM MDT WED MAY 28 2014
VFR CONDITIONS EXPECTED AT ALL 3 TAF SITES...KPUB...KALS AND KCOS
THROUGH TOMORROW AFTERNOON. AN ISOLD WEAK TSRA WILL BE POSSIBLE LATER
THIS AFTERNOON AND TOMORROW AFTERNOON AT KCOS AND KALS...BUT
PROBABILITY TOO LOW TO MENTION EXPLICITLY IN TAF PRODUCT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TAUNTON MA
958 PM EDT THU MAY 29 2014
.SYNOPSIS...
ANOTHER NIGHT OF COOL AND DRY WEATHER FOLLOWED BY A COLD FRONT
WITH SHOWERS AND THUNDERSTORMS FRIDAY INTO FRIDAY NIGHT. COOL
WEATHER LINGERS THROUGH THE WEEKEND...BUT EXPECT WARMER CONDITIONS
INTO EARLY NEXT WEEK PRIOR TO A RENEWED THREAT OF WET-WEATHER BY
MIDWEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
10 PM UPDATE...MADE SOME MINOR ADJUSTMENTS TO TEMPERATURES...
DEWPOINTS...AND SKY COVER TO ACCOUNT FOR THE LATEST TRENDS.
OTHERWISE...THE FORECAST IS ON TRACK.
7 PM UPDATE...
FORECAST IN GOOD SHAPE. ONLY FEW HIGH CLOUDS OVER REGION THIS
EVENING WITH MORE SOLID CLOUD COVER REMAINING BACK ACROSS NEW YORK
STATE. HIGH-RES RAP STILL INSISTS ON LOW CLOUDS/FOG REACHING S
COAST OVERNIGHT. EARLIER DISCUSSION FOLLOWS...
MOSTLY CLEAR SKIES AND LIGHT WINDS WILL LEAD TO ANOTHER EVENING
OF EFFECTIVE RADIATIONAL COOLING. HIGHEST CONFIDENCE ACROSS SE
MA...W-CAPE...AND MARTHAS VINEYARD. WOULD NOT BE SURPRISED TO HAVE
A FEW LOCALES IN THOSE AREAS FALL BELOW 40-DEGREES. THOSE AREAS
THAT RADIATE OUT EFFECTIVELY...WOULD EXPECT PATCHY GROUND FOG.
SOME UNCERTAINTY...WATCHING THE CLOUD DECK WELL OFFSHORE. PLAUSIBLE
THAT WITH S/SE WINDS LOW CLOUDS AND FOG WILL IMPACT THE S-COASTLINE
OF NEW ENGLAND. WILL PREVAIL IN THE FORECAST ACROSS SE CAPE COD
WHERE CONFIDENCE IS HIGHEST. UNCERTAIN AS TO ELSEWHERE. WILL LEAVE
FOR THE OVERNIGHT CREW TO ASSESS.
TO THE W...MID-LEVEL IMPULSE AND ACCOMPANYING TROUGH SWEEP NW-SE
THROUGH THE REGION. BROKEN-OVERCAST CLOUDS VIA SATELLITE ACROSS THE
MID-ATLANTIC TO LAKE ONTARIO ADVECT N AND W IN RESPONSE TO ASCENT
AHEAD OF THE TROUGH AXIS. SOME LIGHT SHOWER ACTIVITY ACROSS N/W-
FACES OF HIGHER TERRAIN IS POSSIBLE. SHOULD SEE MILDER CONDITIONS WITH
LOWS DOWN TO AROUND THE UPPER-40S UNDER LIGHT S/SW-WINDS.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
FRIDAY INTO FRIDAY NIGHT...
ANOTHER MID-LEVEL IMPULSE DIVES NW-SE ACROSS THE NE-CONUS DURING THE
DAY. SUBSEQUENT TROUGHING AND FALLING HEIGHTS PARENT WITH A COLD
FRONT YIELDS AN AREA OF STRONG ASCENT OVER MUCH OF S NEW ENGLAND
BENEATH CYCLING FLOW AND MOIST-ADIABATIC MID-LEVEL LAPSE RATES OF
6C PER KM. EXPECTING A POSSIBLE LINE OF SHOWERS AND
THUNDERSTORMS.
BUT SOME CONSIDERATIONS TO POINT OUT:
WITH CLOUDS ADVECTING E OVERNIGHT WILL ASSUME LESSER DESTABILIZATION
TO THE W. ANTICIPATE CENTRAL-S/E PORTIONS OF S NEW ENGLAND TO SEE
SUNSHINE ALLOWING BOUNDARY-LAYER MIXING AND LOW-LEVEL LAPSE RATES TO
STEEPEN TO DRY-ADIABATIC. INSTABILITY SUBSEQUENTLY BUILDS TO AROUND
500 J/KG...AN AXIS OF WHICH WILL EXIST OVER THE INTERIOR AWAY
FROM THE IMMEDIATE COAST WITH ANTICIPATED ONSHORE SEA-BREEZE
BEHIND WHICH COOLER AND MORE STABLE AIR PREVAILS.
ALSO MUST NOTE THAT STRONGEST WINDS AND BETTER DYNAMICS RESIDE WELL
W OF THE REGION. WHILE NW-SE UNIDIRECTIONAL SHEAR PREVAILS...IT IS
MINOR TO MODEST AT MOST...NOT OVERWHELMING. MORE NOTABLY...0-6 KM
MEAN WINDS NW-SE ARE LIGHT AND CARVED VECTORS ARE NEAR-ZERO.
TAKING THE POINTS ABOVE INTO CONSIDERATION AND EVALUATING HIGH-RES
FORECAST MODELS ALONG WITH THE WEAK WIND PATTERN...ANTICIPATE A LINE
OF SHOWERS TO DEVELOP INITIALLY ALONG THE FRONT...BUT AS IT RACES SE
IT IS LIKELY TO INTERACT WITH A MORE UNSTABLE AIRMASS AND CLASH WITH
THE ONSHORE SEA-BREEZE. EXACTLY WHERE IS SOMEWHAT UNCERTAIN. HIGHEST
CONFIDENCE ACROSS THE INTERIOR W OF THE SEA-BREEZE FRONT.
SHOULD SEE EMBEDDED HEAVY RAIN AND THUNDERSTORMS. LOW CONFIDENCE
CONCERNING SEVERE WEATHER THREATS YET CAN NOT RULE OUT POSSIBLE
HAIL AS WET-BULB FREEZING LEVEL HEIGHTS ARE LOW AROUND 7 KFT. AM
MORE CONCERNED WITH THE THREAT OF HEAVY RAIN ALONG WITH URBAN AND
POOR DRAINAGE FLOODING ESP ALONG THE N/W FACING SLOPES OF HIGH
TERRAIN. PWATS UP TO AN INCH ARE FORECAST. WILL INSERT THE THREAT
OF HEAVY RAIN INTO THE FORECAST. HIGHS GETTING UP TO 70-DEGREES.
ACTIVITY TO LINGER INTO THE EVENING PERIOD GRADUALLY DISSIPATING
OVERNIGHT. CLOUDS AND LIGHT SHOWERY WEATHER LIKELY TO LINGER WITHIN
THE CYCLONIC CONVERGENT FLOW ACROSS E NEW ENGLAND...BUT ALL ASIDE
WITH WINDS PREVAILING OUT OF THE N ANOTHER CHILLY NIGHT IS EXPECTED.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGHLIGHTS...
* COOL ONSHORE FLOW SAT WITH FEW A SHOWERS INLAND
* DRY AND WARMER SUN/MON
* SHOWERS AT TIMES TUE-THU WITH NEAR AVERAGE TEMPS
OVERVIEW...ENSEMBLES AND MEDIUM RANGE MODELS REMAIN IN GOOD
AGREEMENT THROUGH EARLY NEXT WEEK...THEN DIVERGE SIGNIFICANTLY FOR
MID TO LATE WEEK WHICH LENDS LOW CONFIDENCE IN FORECAST. CLOSED LOW
WELL OFF NEW ENGLAND COAST HEADS FARTHER OUT TO SEA SAT...WHICH
ALLOWS SOME OF MIDWEST RIDGING TO SHIFT E INTO OUR AREA SUN/MON.
RIDGE BREAKS DOWN FROM THERE AS NEXT UPPER TROUGH SWINGS DOWN OUT OF
NORTHERN PLAINS. MODELS/ENSEMBLES VARY CONSIDERABLY WITH STRENGTH
AND POSITION OF THIS FEATURE AS IT REACHES GREAT LAKES/NORTHEAST MID
TO LATE WEEK...WHICH AFFECTS POSITION OF WARM FRONT WHICH SHOULD
BECOME STATIONARY NEAR NEW ENGLAND.
SATURDAY...HIGH CONFIDENCE.
LAST SHORT WAVE ROTATING AROUND UPPER LOW WELL OFFSHORE SHOULD
PRODUCE SCATTERED SHOWERS/ISOLATED THUNDER AS COLD TEMPERATURES
ALOFT /NEAR -20C AT 500 MB/ YIELD STEEP MID LEVEL LAPSE RATES.
ACTIVITY SHOULD BECOME FOCUSED OVER WESTERN NEW ENGLAND BY AFTERNOON
AS DRIER AIR ADVECTS IN FROM OCEAN. ONSHORE FLOW WILL KEEP HIGHS IN
60S TO NEAR 70.
SUNDAY AND MONDAY...HIGH CONFIDENCE.
HIGH PRESSURE BUILDS OVER NEW ENGLAND SUN WITH PLENTY OF SUNSHINE
AND AFTERNOON SEA BREEZES. SW FLOW GETS UNDERWAY MON AS HIGH BUILDS
TO MID ATLANTIC COAST WITH INCREASING CLOUDS DURING AFTERNOON AHEAD
OF NEXT SYSTEM. SCATTERED SHOWERS SHOULD ARRIVE MON NIGHT. HIGHS
SHOULD TOP OUT IN 60S COAST/70S INLAND SUN THEN WARM INTO 70S/NEAR
80 MON AWAY FROM S COAST /60S/.
TUESDAY THROUGH THURSDAY...LOW CONFIDENCE.
FORECAST HINGES ON POSITION OF WARM FRONT WHICH IS HIGHLY UNCERTAIN
THIS FAR OUT IN TIME...BUT SHOULD BECOME STATIONARY OVER OR JUST S
OF NEW ENGLAND. EXPECT TO SEE AT LEAST SCATTERED SHOWERS DURING THIS
PERIOD...ESPECIALLY TUE AND AGAIN WED NIGHT/THU PER ENSEMBLES...BUT
ALL THREE DAYS LIKELY TO FEATURE GOOD AMOUNT OF CLOUDS AND S/SE
FLOW. RELYING HEAVILY ON BLEND OF MODEL GUIDANCE WITH HIGHS IN
60S/70S EACH DAY.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT-TERM /THROUGH FRIDAY/...MODERATE CONFIDENCE.
VFR. SEA BREEZES DECAY THIS EVENING. IFR CIGS/VSBYS STILL ON TRACK
TO REACH CAPE COD AND ISLANDS AFTER 06Z AND SHOULD DISSIPATE
AROUND SUNRISE.
HIGHER CONFIDENCE WITH THE DEVELOPMENT OF SHRA/TSRA SWEEPING NW
TO SE BEGINNING FRIDAY MIDDAY AND CONTINUING INTO THE EVENING.
ACCOMPANYING TEMPO MVFR-IFR CONDITIONS POSSIBLE.
KBOS TAF...HIGH CONFIDENCE IN TAF.
KBDL TAF...HIGH CONFIDENCE IN TAF.
OUTLOOK...SATURDAY THROUGH TUESDAY...
SATURDAY...HIGH CONFIDENCE. VFR EXCEPT SCT SHOWERS/LOCAL MVFR ACROSS
WESTERN NEW ENGLAND.
SUNDAY AND MONDAY...HIGH CONFIDENCE. VFR. SEA BREEZES SUN AFTERNOON.
TUESDAY...MODERATE CONFIDENCE. MVFR IN SCT SHOWERS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
.SHORT-TERM /THROUGH FRIDAY/...HIGH CONFIDENCE.
WHILE QUIET BOATING WEATHER IS EXPECTED...WINDS WILL VEER OUT OF
THE S. THERE IS THE CHANCE OF SHOWERS AND POSSIBLY THE THREAT OF
THUNDERSTORMS FRIDAY EVENING.
OUTLOOK...SATURDAY THROUGH TUESDAY...
SATURDAY...HIGH CONFIDENCE. NE WINDS AS LOW PRESSURE PASSES WELL SE
OF NEW ENGLAND...STRONGEST NEAR CAPE COD/ISLANDS BUT SHOULD REMAIN
BELOW SCA. SEAS MAY REACH 5 FT WELL OFFSHORE.
SUNDAY AND MONDAY...HIGH CONFIDENCE. HIGH PRESSURE BUILDS OVER NEW
ENGLAND WITH AFTERNOON SEA BREEZES SUN...THEN MORE OF S/SW FLOW MON
AS HIGH SHIFTS S OF WATERS. LEFTOVER E SWELL NEAR 5 FT MAY PERSIST
ON OUTER WATERS.
TUESDAY...MODERATE CONFIDENCE. S/SE FLOW GETS UNDERWAY AHEAD OF
APPROACHING WARM FRONT WITH SCATTERED SHOWERS. WINDS SHOULD REMAIN
BELOW SCA BUT SEAS ON OUTER WATERS MAY REACH 5 FT.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SIPPRELL/JWD
NEAR TERM...RLG/JWD
SHORT TERM...SIPPRELL
LONG TERM...JWD
AVIATION...SIPPRELL/JWD
MARINE...SIPPRELL/JWD
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
326 PM EDT WED MAY 28 2014
.DISCUSSION...
CURRENTLY/TONIGHT...WEST COAST SEA BREEZE IS A LITTLE MORE ACTIVE
WHERE GREATER MOISTURE EXISTS THIS AFTERNOON. ACROSS EAST CENTRAL
FLORIDA CONVECTION HAS BEEN MORE ISOLATED...DEVELOPING ALONG AND
INLAND OF EAST COAST SEA BREEZE...MAINLY FROM I-95 WEST. STILL
EXPECTING A SLIGHT INCREASE IN SHOWER AND THUNDERSTORM COVERAGE
THROUGH THE REST OF THE DAY. HOWEVER BEST RAIN CHANCES EXIST WEST OF
ORLANDO...ACROSS LAKE COUNTY...WHERE BOTH THE WRF AND HRRR MODELS
CONTINUE TO SHOW THE SEA BREEZE COLLISION LATE AFT/TOWARD SUNSET. A
FEW STRONG STORMS MAY RESULT WITH STRONG WIND GUSTS...SMALL
HAIL...FREQUENT LIGHTNING AND LOCALLY HEAVY RAINFALL THE MAIN
THREATS. SHOWERS AND STORMS WILL DIMINISH OVER THE INTERIOR THROUGH
LATE EVENING AND THEN ONLY A SLIGHT CHANCE FOR ONSHORE MOVING
SHOWERS WILL EXIST ALONG THE SOUTHERN TREASURE COAST OVERNIGHT.
PARTLY CLOUDY SKIES EXPECTED WITH LOWS IN THE UPPER 60S TO LOW
70S.
THU...EXPECTING HIGHER CONVECTIVE COVERAGE TOMORROW AS GFS CONTINUES
TO SHOW A WEAK DISTURBANCE MOVING INTO THE REGION FROM THE GULF AND
MOISTURE INCREASING IN S/SE LOW LEVEL FLOW. HAVE INCREASED RAIN
CHANCES SLIGHTLY BUT STILL ROUGHLY 10-20 PERCENT BELOW MOS GUIDANCE
WITH POPS RANGING FROM 30 AT THE COAST TO 60 PERCENT WEST OF ORLANDO
WHERE LATE DAY BOUNDARY COLLISIONS ARE MORE LIKELY. THIS INCREASE IN
CONVECTION WILL ALSO LEAD TO GREATER CLOUD COVER AND THEREFORE MAX
TEMPS FORECAST TO BE A TAD LOWER...MAINLY OVER THE INTERIOR. HIGHS
WILL RANGE FROM MID 80S ALONG THE COAST TO UPPER 80S/NEAR 90
INLAND.
PREVIOUS DISCUSSION...
FRI-SUN...RAIN CHANCES WILL DROP BACK SOME FRI AND SAT AND EVEN MORE
SO SUNDAY AS A H50 HIGH OVER THE MIDWEST OHIO VALLEY BUILDS SWD OVER
FL...UPSTREAM FROM A TROUGH DIGGING OVER THE WRN ATLC. COMBINATION
OF THESE TWO FEATURES WILL RESULT IN STRENGTHENING ATLC HIGH
PRES...DRIER AIR AND FRESHENING ONSHORE FLOW SUNDAY INTO EARLY NEXT
WEEK. FOR SAT...CONTINUED TREND OF HIGHER POPS INLAND...AND NUDGED
THEM UP AROUND LAKE OKEE OWING TO DEEPER MOISTURE/LOWEST MID LEVEL
HGTS...AND POTENTIAL SEA/LAKE BREEZE INTERACTION. DROPPED SUNDAY
POPS BACK TO SLGT CHC ALL AREAS...AS SFC EASTERLIES BEGIN TO
FRESHEN. TEMPS LOOK TO BE A LITTLE ABOVE CLIMO THRU SAT...BEFORE
FALLING TO NEAR NORMAL SUN.
MON-WED...HIGH CENTER WILL DROP SOUTH OVER THE TOP OF FL THROUGH TUE
AS THE AXIS OF THE ATLC SURFACE HIGH ALSO DROPS SWD. MEAN DRYING...
WITH A VERY DRY/SUBSIDENT MID LEVEL ATMOSPHERE...SHOULD SUPPRESS
SIGNIFICANT CONVECTION WITH TEMPS NEAR TO SLIGHTLY ABOVE NORMAL. BY
NEXT WED...THERE ARE SOME INDICATIONS BY THE ECM THAT SOME CARIBBEAN
MOISTURE COULD CREEP BACK NORTHWARD AS THE MID LEVEL RIDGE STARTS TO
BREAK DOWN. THE GFS ON THE OTHER HAND KEEPS HIGHER H50 HGTS AND DRIER
AIR LOCKED IN A DAY LONGER BEFORE STARTING TO SIGNIFICANTLY MOISTEN
THE LOCAL AIR MASS. IN DEFERENCE TO THE ECM....ADDED A SMALL POP FOR
DAY 8 (NEXT WED). TEMPS SHOULD REMAIN NEAR TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION...TEMPO IFR/MVFR CONDS IN ISO SHRA/TSRA ACTIVITY ALONG AND
INLAND OF THE EAST COAST SEA BREEZE. INCREASE IN COVERAGE EXPECTED
WITH SEA BREEZE COLLISION ACROSS LAKE COUNTY NEAR TO JUST BEFORE 00Z
WITH CONVECTION WINDING DOWN THROUGH LATE EVENING. VFR CONDS
GENERALLY EXPECTED OVERNIGHT WITH PATCHY GROUND FOG POSSIBLY
PRODUCING BRIEF MVFR VISIBILITIES BTWN 10-13Z. GREATER CHANCE FOR
SHOWERS AND THUNDERSTORMS...ESPECIALLY ACROSS THE INTERIOR THURSDAY
AFTERNOON WITH TEMPO IFR/MVFR CONDS ONCE AGAIN EXPECTED.
&&
.MARINE...
TONIGHT...SOUTHEAST WINDS AROUND 10 KNOTS WILL DECREASE OVERNIGHT
BECOMING S/SE 5-10 KNOTS. SEAS RANGING FROM 2-3 FEET.
THU-SUN...(PREVIOUS DISCUSSION) BENIGN BOATING WEATHER CONTINUES
THROUGH SATURDAY IN A GENTLE SEA BREEZE WITH SEAS RUNNING AROUND
2FT OR A LITTLE LESS NEAR SHORE AND 2-3FT WELL OFFSHORE. BY
SUNDAY...FRESHENING EASTERLY WINDS UP TO 15-20KT WILL PUSH
OFFSHORE SEAS UP TO 5-6FT AND COULD POSSIBLY NECESSITATE A
CAUTIONARY STMT FOR THE 20-60NM LEGS NORTH OF SEBASTIAN INLET.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 71 86 70 88 / 10 30 20 40
MCO 71 89 69 91 / 20 50 30 40
MLB 72 86 71 88 / 10 30 20 40
VRB 71 85 69 87 / 10 30 20 40
LEE 72 89 72 90 / 40 60 30 40
SFB 72 90 71 91 / 20 50 30 40
ORL 73 90 72 90 / 20 50 30 40
FPR 70 85 69 87 / 10 30 20 40
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
PUBLIC/MARINE/AVIATION...WEITLICH
RADAR/IMPACT WX...SPRATT
AREA FORECAST DISCUSSION
NWS MIAMI FL
1129 AM EDT WED MAY 28 2014
.UPDATE...MOISTURE HAS INCREASED A BIT SINCE YESTERDAY WITH THE
PWAT ON THE MIAMI SOUNDING THIS MORNING AT 1.53 INCHES. MORE
SHOWERS AND A FEW THUNDERSTORMS HAVE ALREADY BEEN OCCURRING ACROSS
THE EASTERN HALF OF SOUTH FL THIS MORNING. THE FORECAST IS ON
TRACK WITH CONVECTION EXPECTED TO CONCENTRATE OVER THE WESTERN
INTERIOR THIS AFTERNOON. MOISTURE WILL CONTINUE TO STEADILY
INCREASE OVER THE NEXT FEW DAYS WITH SCATTERED THUNDERSTORMS
EXPECTED. /GREGORIA
&&
.PREV DISCUSSION... /ISSUED 746 AM EDT WED MAY 28 2014/
AVIATION...
DEEPER MOISTURE WILL CONTINUE TO MOVE INTO THE REGION THROUGH THE
TAF PERIOD. STREAMER SHOWERS WILL CONTINUE TO DEVELOP OVER THE
ATLANTIC WATERS AND A FEW COULD PUSH IN TOWARDS THE EAST COAST TAF
SITES THIS MORNING...SO HAVE VCSH THROUGH 16Z. IN ADDITION...THE
LATEST RUN OF THE HRRR SHOWS SHOWER ACTIVITY DEVELOPING CLOSER TO
THE EAST COAST ON THE EAST COAST SEA BREEZE LATER THIS MORNING
BEFORE SHIFTING TOWARDS THE INTERIOR AND GULF COAST THIS
AFTERNOON. AT KAPF...EXPECT A GULF COAST SEA BREEZE TO DEVELOP
AROUND 18Z...WITH SHOWERS AND STORMS MAINLY TO THE EAST OF THE TAF
SITE. KEPT VCSH AT KAPF...AND WILL REASSESS LIGHTNING RISK THIS
AFTERNOON. VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD
OUTSIDE OF ANY SHOWERS THAT HAPPEN TO MOVE OVER A TAF SITE.
PREV DISCUSSION... /ISSUED 407 AM EDT WED MAY 28 2014/
DISCUSSION...
ISOLATED LIGHT TO MODERATE RAIN SHOWERS CONTINUE TO PUSH WEST ACROSS
THE ATLANTIC WATERS AND TOWARD THE FLORIDA MAINLAND. A FEW OF THESE
SHOWERS MAY MAKE IT ASHORE BROWARD OR MIAMI-DADE COUNTY LATER THIS
MORNING BEFORE DISSIPATING.
SIMILAR SCENARIO IS EXPECTED TODAY AS HAS BEEN THE CASE OVER THE
LAST FEW DAYS. EASTERLY FLOW SHOULD DOMINATE WITH SEA BREEZE INDUCED
SHOWERS AND THUNDERSTORMS DEVELOPING MAINLY ACROSS THE INTERIOR AND
GULF COASTAL AREAS LATER THIS AFTERNOON AND EARLY EVENING.
HOWEVER...MODEL SOUNDINGS DEPICT H5 TEMPERATURES TO BE A BIT COOLER
THAN YESTERDAY...AROUND -10C ACROSS THE INTERIOR. THIS COMBINED WITH
WEAK CAPPING AND LOCALIZED SEA BREEZE CONVERGENCE COULD PRODUCE A
FEW STRONG THUNDERSTORMS WITH GUSTY WINDS AND SMALL HAIL BEING THE
MAIN THREATS ALONG WITH FREQUENT LIGHTNING.
A DEEPER MOISTURE PLUME IS THEN EXPECTED TO PUSH INTO THE FLORIDA
PENINSULA FROM THE SOUTHWEST THURSDAY INTO FRIDAY INCREASING PWAT
VALUES TO AROUND 1.75 INCHES. THIS WILL FACILITATE BETTER OVERALL
COVERAGE OF SHOWERS AND THUNDERSTORMS ACROSS THE AREA WITH THE BEST
CHANCES STILL REMAINING ACROSS THE INTERIOR AND WEST.
MODELS DEPICT THIS MORE CONVECTIVE SEASON TYPE REGIME TO PERSIST
THROUGH THE WEEKEND AND INTO NEXT WEEK WITH DAILY CHANCES FOR MAINLY
AFTERNOON AND EARLY EVENING SHOWERS AND THUNDERSTORMS. BY
TUESDAY...MODELS STILL HINT AT A WEAK BACK DOOR COLD FRONT PUSHING
IN FROM THE NORTHEAST WITH RELATIVELY DRIER AIR BEHIND IT. THERE IS
STILL UNCERTAINTY AS TO THE SOUTHWARD PUSH OF THIS FRONT...SO WILL
STAY WITH PERSISTENCE FOR NOW.
AVIATION...
A WEAK BERMUDA HIGH CONTINUES TO BRING EASTERLY FLOW TO SOUTH
FLORIDA. VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. THE
EXCEPTION WILL BE FOR ANY CONVECTIVE CELLS THAT ARE ABLE TO
DEVELOP AND IMPACT A TAF SITE. WITH THE EAST FLOW, THIS WILL
MAINLY BE KAPF, ALTHOUGH THERE IS A SLIGHT CHANCE ALONG THE
ATLANTIC COAST AS WELL. GIVEN THE LOW CHANCES OF IT OCCURRING
ALONG THE EAST COAST, LESS THAN 25 PERCENT, HAVE DROPPED MENTION
OF VCSH FOR ALL BUT KAPF, WHICH DOES ALSO HAVE A SLIGHT CHANCE TO
SEE TSRA AS WELL, ALTHOUGH AGAIN, THE CHANCES ARE LOW ENOUGH THAT
IT CURRENTLY DOES NOT WARRANT A MENTION IN THE TAFS AT THIS TIME.
MARINE...
TRANQUIL MARINE CONDITIONS WILL PERSIST THROUGH THE REMAINDER OF
THE WEEK AND INTO THE WEEKEND WITH EAST WINDS OF 5-15 KNOTS AND
SEAS AROUND 4 FEET OR LESS. CHANCES FOR AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE EACH DAY MAINLY OVER
LAKE OKEECHOBEE AND THE GULF WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 76 86 72 / 20 20 30 20
FORT LAUDERDALE 86 77 86 74 / 20 20 30 20
MIAMI 88 76 87 74 / 20 20 30 20
NAPLES 91 72 88 71 / 20 20 60 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
858 AM EDT WED MAY 28 2014
.DISCUSSION...
RIDGE AXIS OF HIGH PRESSURE OVER THE ATLANTIC REMAINS NEAR TO JUST
NORTH OF THE AREA THIS MORNING WITH PROFILER WINDS VERIFYING A WEAK
SOUTH-SOUTHEAST LOW LEVEL FLOW OVER THE REGION. MORNING SOUNDINGS
INDICATE MOISTURE HAS INCREASED OVER THE PAST 24 HOURS WITH PW
VALUES AT XMR AT 1.5" AND TBW UP TO 1.8". THIS WILL LEAD TO
SLIGHTLY HIGHER CHANCES FOR AFTERNOON SHOWERS AND THUNDERSTORMS
ESPECIALLY OVER THE INTERIOR TODAY. EAST COAST SEA BREEZE WILL
DEVELOP AND MOVE GRADUALLY INLAND THIS AFTERNOON WITH ISOLATED
SHOWERS AND STORMS POSSIBLE INITIALLY ALONG THE COAST AND THEN
SCATTERED CONVECTION FORMING ACROSS THE INTERIOR FROM MID TO LATE
AFTERNOON. HAVE INCREASED RAIN CHANCES UP TO 40 PERCENT ACROSS LAKE
COUNTY FOR TODAY AS BOTH THE HRRR AND LOCAL WRF RUNS INDICATE THIS
IS FAVORED LOCATION FOR SEA BREEZE COLLISION AND GREATER STORM
COVERAGE TOWARD LATE AFT/NEAR SUNSET.
500MB TEMPS EXPECTED TO COOL SLIGHTLY TODAY TO AROUND -10C AS A WEAK
SHORTWAVE APPROACHES FROM THE GULF. IN ADDITION MORNING XMR SOUNDING
SHOWS SOME LINGERING DRY AIR ALOFT. THIS WILL FAVOR A FEW STRONG
STORMS...MAINLY WITH ANY BOUNDARY INTERACTIONS OVER THE INTERIOR
LATER THIS AFTERNOON. THE MAIN THREATS WILL BE STRONG WIND GUSTS...
SMALL HAIL...AND FREQUENT CLOUD TO GROUND LIGHTING. A WEAK SOUTHERLY
STEERING FLOW WILL ALSO KEEP THE POTENTIAL FOR LOCALLY HEAVY
RAINFALL TO OCCUR FROM SLOW MOVING STORMS.
TEMPERATURES WILL REMAIN NEAR NORMAL WITH HIGHS IN THE MID-UPPER 80S
ALONG THE COAST TO LOW 90S INLAND.
&&
.AVIATION...VFR CONDS THROUGH THIS MORNING. THEN TEMPO IFR/MVFR
CONDS WILL OCCUR WITH ANY ISO-SCT SHRA/TSRA THAT DEVELOP ALONG AND
INLAND OF THE EAST COAST SEA BREEZE THIS AFTERNOON. BEST CHANCE FOR
THIS ACTIVITY WILL BE OVER THE INTERIOR...ESPECIALLY TOWARD LAKE
COUNTY LATE TODAY WHERE THE SEA BREEZE COLLISION IS EXPECTED TO
OCCUR.
&&
.MARINE...S/SE WINDS AROUND 5-10 KNOTS WILL BECOME E/SE AND
INCREASE UP TO AROUND 10 KNOTS AS THE EAST COAST SEA BREEZE
DEVELOPS AND MOVES INLAND THIS AFTERNOON. SEAS WILL RANGE FROM 2-3
FEET. SLIGHTLY HIGHER CHANCE FOR AFTERNOON THUNDERSTORMS BUT MUCH
OF THIS ACTIVITY IS EXPECTED TO REMAIN OVER LAND AREAS TODAY.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
WEITLICH/SPRATT
AREA FORECAST DISCUSSION
NWS MIAMI FL
746 AM EDT WED MAY 28 2014
.AVIATION...
DEEPER MOISTURE WILL CONTINUE TO MOVE INTO THE REGION THROUGH THE
TAF PERIOD. STREAMER SHOWERS WILL CONTINUE TO DEVELOP OVER THE
ATLANTIC WATERS AND A FEW COULD PUSH IN TOWARDS THE EAST COAST TAF
SITES THIS MORNING...SO HAVE VCSH THROUGH 16Z. IN ADDITION...THE
LATEST RUN OF THE HRRR SHOWS SHOWER ACTIVITY DEVELOPING CLOSER TO
THE EAST COAST ON THE EAST COAST SEA BREEZE LATER THIS MORNING
BEFORE SHIFTING TOWARDS THE INTERIOR AND GULF COAST THIS
AFTERNOON. AT KAPF...EXPECT A GULF COAST SEA BREEZE TO DEVELOP
AROUND 18Z...WITH SHOWERS AND STORMS MAINLY TO THE EAST OF THE TAF
SITE. KEPT VCSH AT KAPF...AND WILL REASSESS LIGHTNING RISK THIS
AFTERNOON. VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD
OUTSIDE OF ANY SHOWERS THAT HAPPEN TO MOVE OVER A TAF SITE.
&&
.PREV DISCUSSION... /ISSUED 407 AM EDT WED MAY 28 2014/
DISCUSSION...
ISOLATED LIGHT TO MODERATE RAIN SHOWERS CONTINUE TO PUSH WEST ACROSS
THE ATLANTIC WATERS AND TOWARD THE FLORIDA MAINLAND. A FEW OF THESE
SHOWERS MAY MAKE IT ASHORE BROWARD OR MIAMI-DADE COUNTY LATER THIS
MORNING BEFORE DISSIPATING.
SIMILAR SCENARIO IS EXPECTED TODAY AS HAS BEEN THE CASE OVER THE
LAST FEW DAYS. EASTERLY FLOW SHOULD DOMINATE WITH SEA BREEZE INDUCED
SHOWERS AND THUNDERSTORMS DEVELOPING MAINLY ACROSS THE INTERIOR AND
GULF COASTAL AREAS LATER THIS AFTERNOON AND EARLY EVENING.
HOWEVER...MODEL SOUNDINGS DEPICT H5 TEMPERATURES TO BE A BIT COOLER
THAN YESTERDAY...AROUND -10C ACROSS THE INTERIOR. THIS COMBINED WITH
WEAK CAPPING AND LOCALIZED SEA BREEZE CONVERGENCE COULD PRODUCE A
FEW STRONG THUNDERSTORMS WITH GUSTY WINDS AND SMALL HAIL BEING THE
MAIN THREATS ALONG WITH FREQUENT LIGHTNING.
A DEEPER MOISTURE PLUME IS THEN EXPECTED TO PUSH INTO THE FLORIDA
PENINSULA FROM THE SOUTHWEST THURSDAY INTO FRIDAY INCREASING PWAT
VALUES TO AROUND 1.75 INCHES. THIS WILL FACILITATE BETTER OVERALL
COVERAGE OF SHOWERS AND THUNDERSTORMS ACROSS THE AREA WITH THE BEST
CHANCES STILL REMAINING ACROSS THE INTERIOR AND WEST.
MODELS DEPICT THIS MORE CONVECTIVE SEASON TYPE REGIME TO PERSIST
THROUGH THE WEEKEND AND INTO NEXT WEEK WITH DAILY CHANCES FOR MAINLY
AFTERNOON AND EARLY EVENING SHOWERS AND THUNDERSTORMS. BY
TUESDAY...MODELS STILL HINT AT A WEAK BACK DOOR COLD FRONT PUSHING
IN FROM THE NORTHEAST WITH RELATIVELY DRIER AIR BEHIND IT. THERE IS
STILL UNCERTAINTY AS TO THE SOUTHWARD PUSH OF THIS FRONT...SO WILL
STAY WITH PERSISTENCE FOR NOW.
AVIATION...
A WEAK BERMUDA HIGH CONTINUES TO BRING EASTERLY FLOW TO SOUTH
FLORIDA. VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. THE
EXCEPTION WILL BE FOR ANY CONVECTIVE CELLS THAT ARE ABLE TO
DEVELOP AND IMPACT A TAF SITE. WITH THE EAST FLOW, THIS WILL
MAINLY BE KAPF, ALTHOUGH THERE IS A SLIGHT CHANCE ALONG THE
ATLANTIC COAST AS WELL. GIVEN THE LOW CHANCES OF IT OCCURRING
ALONG THE EAST COAST, LESS THAN 25 PERCENT, HAVE DROPPED MENTION
OF VCSH FOR ALL BUT KAPF, WHICH DOES ALSO HAVE A SLIGHT CHANCE TO
SEE TSRA AS WELL, ALTHOUGH AGAIN, THE CHANCES ARE LOW ENOUGH THAT
IT CURRENTLY DOES NOT WARRANT A MENTION IN THE TAFS AT THIS TIME.
MARINE...
TRANQUIL MARINE CONDITIONS WILL PERSIST THROUGH THE REMAINDER OF
THE WEEK AND INTO THE WEEKEND WITH EAST WINDS OF 5-15 KNOTS AND
SEAS AROUND 4 FEET OR LESS. CHANCES FOR AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE EACH DAY MAINLY OVER
LAKE OKEECHOBEE AND THE GULF WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 76 86 72 / 20 20 30 20
FORT LAUDERDALE 86 77 86 74 / 20 20 30 20
MIAMI 88 76 87 74 / 20 20 30 20
NAPLES 91 72 88 71 / 20 20 60 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...10/CD
LONG TERM....10/CD
AVIATION...84/AK
AREA FORECAST DISCUSSION...UPDATED
NWS COLUMBIA SC
1037 AM EDT WED MAY 28 2014
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL CIRCULATE A MOIST SOUTHERLY
FLOW INTO THE FORECAST AREA THROUGH TONIGHT. A COLD FRONT WILL
PUSH SOUTHWARD INTO THE NORTHERN PORTION OF SOUTH CAROLINA BY
THURSDAY AND THEN CONTINUE SLOWLY AND THROUGH THE AREA BY FRIDAY
NIGHT/EARLY SATURDAY...STALLING JUST SOUTH OF THE AREA THROUGH THE
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AREA OF LIGHT SHOWERS MOVING NORTHEASTWARD INTO THE COLUMBIA AREA
THIS MORNING HAS SINCE DISSIPATED AS THAT BATCH OF ENHANCED CLOUDS
HAS SHIFTED INTO THE EASTERN MIDLANDS AND TOWARDS THE COASTAL
PLAIN. THE 14Z VISIBLE SATELLITE IMAGERY INDICATES THE POSSIBILITY
OF A WEAK SHORTWAVE TRAPPED BENEATH THE WEAK UPPER RIDGE OVER THE
AREA...AS NOTED BY THE CYCLONIC CIRCULATION OF THE MID LEVEL
CLOUDS MOVING INTO THE SOUTHERN PART OF THE FORECAST AREA. 12Z
RAOB SOUNDING AT CHS SHOWS PWAT VALUES CLOSE TO 1.7 INCHES WITH
MODERATE INSTABILITY AND CONVECTIVE TEMP IN THE MID 80S WHICH
SHOULD EASILY BE REACHED. HOWEVER...RUC/NAM FORECAST SOUNDINGS AT
CAE SHOW DRIER AIR IN PLACE THIS AFTERNOON IN THE MID LEVELS WITH
RUC GIVING PWAT VALUES AS LOW AS 1.1 INCHES...NOT FAVORABLE FOR
WIDESPREAD CONVECTION. THINK THIS MIGHT BE ON THE LOW SIDE THOUGH.
STILL EXPECT ISOLATED CONVECTION AS NOTED ON OUR LOCAL WRF AND
LATEST RUNS OF THE HRRR AND OTHER HI-RES MODEL RUNS. WILL CARRY
CHANCE POPS IN THE EASTERN MIDLANDS AHEAD OF THE POSSIBLE WEAK
SHORTWAVE WITH SLIGHT CHANCE POPS ELSEWHERE THROUGH
AFTERNOON...THEN SHOW AN AREA OF CHANCE POPS IN THE CSRA WHICH
COULD BE ANOTHER FAVORED AREA AGAIN FOR CONVECTION DEVELOPING IN
DIFFLUENT FLOW OVER CENTRAL GEORGIA AND DRIFTING EASTWARD WITH THE
MEAN FLOW IN A MODERATELY UNSTABLE ENVIRONMENT. ONCE AGAIN THE
POSSIBILITY FOR AN ISOLATED SEVERE STORM CANNOT BE RULED OUT WITH
MAIN THREAT WILL ONCE AGAIN BE STRONG WINDS AND LARGE HAIL.
EXPECT AFTERNOON HIGH TEMPERATURES TO BE AROUND 90 DEGREES ACROSS
THE AREA.
TONIGHT...WITH S/W MOVING TOWARD/ACROSS THE AREA TONIGHT...THE
CONVECTION COULD LINGER INTO THE EVENING HOURS. OTHERWISE...PLENTY
OF MID/HIGH LEVEL CLOUDS. WILL CONTINUE WITH A CHANCE/SLIGHT
CHANCE FOR SHOWERS/THUNDER THROUGH LATE EVENING ACROSS THE AREA.
A COLD FRONT WILL BE APPROACHING FROM THE NORTH...BUT NOT
EXPECTED TO MAKE IT INTO THE REGION UNTIL THURSDAY. TEMPERATURES
ARE EXPECTED TO BE NEAR/SLIGHTLY ABOVE GUIDANCE WITH LOWS IN THE
MIDDLE TO UPPER 60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
OVERALL PATTERN WILL BE SLOW TO CHANGE THROUGH THURSDAY NIGHT AS
THE UPPER LOW BECOME QUASI-STATIONARY OVER THE WESTERN GULF AREA
AND A WEAK SURFACE FRONT MOVES TOWARD THE REGION FROM THE NORTH.
THIS WILL KEEP THE FORECAST AREA UNDER SOUTHERLY FLOW WITH CHANCES
OF MAINLY AFTERNOON AND EVENING THUNDERSTORMS EACH DAY.
INSTABILITY WILL BE MODERATE ON WEDNESDAY AND SLIGHTLY LOWER ON
THURSDAY WHICH WILL COMBINE WITH PWAT VALUES AROUND 1.6 INCHES.
THREAT OF SEVERE REMAINS LOW AS FREEZING LEVEL REMAINS HIGH AND
WINDS THROUGH THE COLUMN WILL BE LIGHT. AS SUCH MAIN SEVERE THREAT
WILL BE FROM STRONG GUSTY WINDS. TEMPERATURES THROUGH THE SHORT
TERM WILL BE IN THE UPPER 80S TO LOWER 90S FOR AFTERNOON HIGHS
WITH OVERNIGHT LOWS IN THE MIDDLE TO UPPER 60S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
MODELS CONTINUE IN GOOD AGREEMENT WITH THE REMAINS OF THE UPPER LOW
OVER THE CENTRAL GULF STATES AND A WEAK FRONTAL BOUNDARY CROSSING
THE REGION. FRONT WILL SLOWLY CROSS THE FORECAST AREA ON FRIDAY AS
THE UPPER LEVEL RIDGE BUILDS INTO THE EASTERN US. BY SUNDAY THE
FRONT WILL BE SLIDING SOUTH OF THE AREA AS A DEEPENING UPPER LOW
TRACKS SOUTHEASTWARD FROM THE NEW ENGLAND STATES SATURDAY MORNING TO
OFF THE DELMARVA COAST BY SATURDAY EVENING. MODEL SOUNDINGS INDICATE
PWAT VALUES IN EXCESS OF 1.6 INCHES REMAINING ACROSS THE FORECAST
AREA ON FRIDAY AND SATURDAY WHICH WILL COMBINE WITH HEATING TO
CONTINUE THE CHANCE OF AFTERNOON AND EVENING CONVECTION. HAVE NOT
MADE SIGNIFICANT CHANGES TO THE POPS FOR FRIDAY AND SATURDAY AS FLOW
ALOFT WILL BE WEAK LIMITING DIVERGENCE ALOFT...AS SUCH EXPECT
CONVECTION COVERAGE TO BE SCATTERED. DRIER AIR WILL BE MOVING INTO
THE REGION FOR SUNDAY ONWARD AS SURFACE HIGH PRESSURE SLIDES
SOUTHWARD ALONG THE EASTERN SEABOARD. TEMPERATURES THROUGH THE LONG
TERM WILL BE NEAR NORMAL TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
GENERALLY VFR CONDITIONS EXPECTED OUTSIDE OF THUNDERSTORMS.
ANOTHER DAY SIMILAR TO TUESDAY EXPECTED WITH SCATTERED AFTERNOON
CONVECTION WITH A YET TO BE DETERMINED FAVORED AREA TO IMPACT
TERMINALS. NO MENTION IN TAFS AT THIS TIME...WILL NEED TO SEE HOW
CONVECTION DEVELOPS DURING THE LATE MORNING /EARLY AFTERNOON
HOURS. LIGHT AND VARIABLE WINDS WILL PICK UP FROM THE WEST
SOUTHWEST BY 15Z AROUND 8 TO 10 KNOTS. BY EVENING...WINDS WILL
DIMINISH AND BE LIGHT AND VARIABLE.
EXTENDED AVIATION OUTLOOK...MAINLY DIURNAL CONVECTION MAY CAUSE
BRIEF MVFR CONDITIONS DURING THE LATE AFTERNOON AND EARLY EVENING
HOURS THURSDAY THROUGH SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
NEAR TERM...HC
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
133 AM EDT WED MAY 28 2014
.UPDATE...
/ISSUED AT 931 PM EDT TUE MAY 27 2014/
CONVECTION RIDING OLD OUTFLOW BOUNDARIES ACROSS EASTERN AL IS
APPROACHING THE STATE LINE. THE HRRR HAS A DECENT HANDLE ON THE
STORMS...AND HAVE FOLLOWED CLOSELY. STORMS HAVE EXHIBITED A
WEAKENING TREND OVER THE LAST HOUR...AND EXPECT THAT TREND TO
CONTINUE.
HAVE UPPED POPS IN THE SE. TWEAKED HOURLY TEMP/DEW GRIDS.
&&
.PREV DISCUSSION... /ISSUED 734 PM EDT TUE MAY 27 2014/
PREV DISCUSSION... /ISSUED 309 PM EDT TUE MAY 27 2014/
SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
STORMS THUS FAR THIS AFTERNOON ARE BEHAVING LARGELY AS EXPECTED
WITH MAIN ACTIVITY DEVELOPING ALONG THE LEAD EDGE OF STRATUS DECK
OVER WEST GEORGIA. WILL NEED TO WATCH CLOSELY POTENTIAL FOR
RECOVERY OVER WEST GEORGIA AS BREAKS IN THE CLOUDS UPSTREAM COULD
LEAD TO A RESURGENCE IN CAPE VALUES LATE THIS AFTERNOON.
OTHERWISE...STORMS SHOULD CONTINUE TO PROGRESS EAST THROUGH THIS
EVENING WITH SOUTHERN SECTIONS MORE FAVORED WHERE DEEP LAYER
MOISTURE IS THE MOST PLENTIFUL.
ONCE STORMS DIE OFF LATE THIS EVENING...NOT MUCH IN THE WAY OF
SENSIBLE WEATHER FOR THE OVERNIGHT PERIOD. MODELS HAVE NOT BEEN
DOING A VERY GOOD JOB WRT THE STRATUS DECKS FORMING AND THIS ROUND
OF MODELS SHOWS VERY LITTLE POTENTIAL AS WELL. KEPT SKY GRIDS
HIGHER THAN WHAT MODELS INDICATE BUT STOPPED SHORT OF INCLUDING
LOW OVERCAST FOR NOW.
DEVELOPMENT OR LACK THEREOF OF STRATUS WILL PLAY A SIGNIFICANT
ROLE IN CONVECTIVE POTENTIAL ON WED. IF STRATUS IS UNABLE TO
FORM...WEST GA WILL BE FAVORED FOR MORE ROBUST DEVELOPMENT AS
UPPER LOW SHIFTING EAST CREATES SLIGHT DIFFLUENT PATTERN ALOFT.
THESE STORMS WILL THEN TRANSLATE EAST WITH THE MEAN FLOW WITH GOOD
COVERAGE OF STORMS FROM ATHENS TO MACON FOR THE LATE AFTERNOON
INTO THE EVENING HOURS. JUST CANT RID OURSELVES OF THE MARGINALLY
LARGE LAPSE RATES OR THE COLD POOL ALOFT SO STRONG STORMS WITH
ISOLATED SEVERE WILL REMAIN POSSIBLE THROUGH THE PERIOD.
DEESE
LONG TERM /THURSDAY THROUGH TUESDAY/...
PATTERN STILL LOOKS FAVORABLE FOR TYPICAL SUMMER-LIKE DIURNALLY
DRIVEN CONVECTION THROUGH THE END OF THE WEEK AND THUS CURRENT
FORECAST STILL APPEARS TO BE ON TRACK WITH SOME STRONG TO SEVERE
STORMS POSSIBLE. BY THE BEGINNING OF NEXT WEEK THOUGH...THE
COMBINATION OF THE INFLUENCE OF UPPER RIDGING AND A SFC HIGH MAY
HELP TO SUPPRESS CONVECTION ACROSS PORTIONS OF THE EASTERN HALF OF
THE CWA. THIS AGAIN IS SIMILAR TO THE PREVIOUS FORECAST THINKING
AND HAVE CONTINUED SLIGHTLY LOWER POPS FOR ABOUT HALF OF THE CWA
ON MONDAY AND TUESDAY. THE PREVIOUS DISCUSSION FOLLOWS.
11
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
OVERALL GOOD AGREEMENT AMONG MODEL SOLUTIONS WITH FEATURES OF LONG
TERM. WEAKENING UPPER LOW AND BROAD MOISTURE FIELD WILL SETTLE INTO
THE SOUTHEAST CONUS THROUGH THE REST OF THE WEEK AND ALLOW FOR A
TYPICAL SUMMER-LIKE ACTIVE DIURNAL CONVECTIVE PATTERN. HAVE GONE
WITH GENERAL CHANCE POPS FOR DAYTIME AND SLIGHT POPS OVERNIGHT AS
DISTINGUISHING LOCATIONS OF HIGHER OR LOWER CHANCES IS NEARLY
IMPOSSIBLE SINCE CONVECTIVE INITIATION EACH DAY WILL LIKELY BE
FOCUSED ON WHERE OLD OUTFLOWS OR OTHER BOUNDARIES END UP FROM
PREVIOUS EVENING ACTIVITY...THEN BECOME OUTFLOW DRIVEN AFTER
ACTION GETS GOING. ENVIRONMENT LOOKS TO BE MODERATELY UNSTABLE AND
LITTLE TO NO SHEAR EACH DAY WITH LOW END MID-LEVEL LAPSE RATES.
CAN EXPECT SOME STORMS TO REACH STRONG INTENSITIES AND A FEW COULD
BE SEVERE.
AN UPPER RIDGE LOOKS TO BEGIN TAKING OVER BY LATE SATURDAY INTO
SUNDAY ALONG WITH A BACKDOOR COLD FRONT DRIVEN BY THE SFC HIGH
SLIDING SOUTHWARD ALONG THE EASTERN SEABOARD. THIS MAY SERVE TO
LIMIT INSTABILITY AND CONVECTIVE POTENTIAL IN EASTERN PORTIONS OF
THE AREA INTO EARLY NEXT WEEK. HAVE DECREASED SOME POPS ACCORDINGLY
FOR NOW.
FOR TEMPS...A GENERAL BLEND STILL LOOKING A BIT TOO HIGH FOR LATE
WEEK MAX VALUES GIVEN CLOUD COVERAGE SO BUMPED DOWN A BIT.
BAKER
&&
.AVIATION...
06Z UPDATE...
MOST OF THE CONVECTION HAS DISSIPATED AND NO MORE IS EXPECTED AT THE
TAFS THROUGH THIS MORNING. LIGHT FOG SHOULD DEVELOP IN THE CSG/MCN
AREAS WHERE RAIN FELL EARLIER THIS EVENING IN AND NEAR THESE AREAS.
CU FIELD SHOULD DEVELOP LATE THIS MORNING WITH SCATTERED CONVECTION
DEVELOPING THIS AFTERNOON. MOST OF THE CONVECTION IS EXPECTED ACROSS
THE WESTERN PART OF THE FORECAST AREA THIS AFTERNOON. WINDS SHOULD
REMAIN SOUTHWEST THROUGH THE FORECAST.
//ATL CONFIDENCE...06Z UPDATE...
HIGH CONFIDENCE ON ALL ITEMS
17
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 66 88 64 90 / 30 30 30 40
ATLANTA 69 85 68 88 / 40 30 30 40
BLAIRSVILLE 60 80 58 84 / 30 30 20 40
CARTERSVILLE 65 85 63 88 / 30 40 30 40
COLUMBUS 69 86 67 89 / 70 40 40 40
GAINESVILLE 66 85 66 87 / 30 30 30 40
MACON 67 87 64 89 / 50 40 40 40
ROME 65 84 63 88 / 30 40 30 40
PEACHTREE CITY 63 85 63 88 / 40 40 30 40
VIDALIA 69 89 70 90 / 60 50 40 40
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS POCATELLO ID
941 AM MDT WED MAY 28 2014
.UPDATE...FORECAST STILL LOOKS IN LINE AS A BIT OF MOISTURE
STREAMS INTO THE AREA TODAY FROM A LOW LOCATED IN WESTERN OREGON.
BEST CHANCE FOR SHOWERS STILL LOOKS TO BE ALONG THE DIVIDE AND THE
EXTREME SE CORNER OF IDAHO. HOWEVER...THE NEW NAM AND HRRR RUNS
ARE IN AND ARE SHOWING A BIT OF CONVECTION IN THE SNAKE
PLAIN...BUT HAVE LOW CONFIDENCE IN THAT SOLUTION. FORECAST HIGHS
ARE SLIGHTLY LOWER THAN THE CONVECTIVE TEMPERATURE FROM FORECAST
SOUNDINGS...THOUGH LAPSE RATES ARE STEEP ENOUGH TO SUPPORT
CONVECTION...IF IT CAN GET STARTED. ANY CONVECTION IN THESE AREAS
WILL PROBABLY BE LATER IN THE AFTERNOON. WILL BE MONITORING SHOWER
ACTIVITY THROUGH THE DAY.
&&
.PREV DISCUSSION... /ISSUED 335 AM MDT WED MAY 28 2014/
SHORT TERM...TODAY THROUGH FRIDAY. THE CURRENT WATER VAPOR
IMAGERY SHOWS AN UPPER LEVEL LOW MOVING INLAND OVER THE OREGON
COAST WITH A DRY SOUTHWEST FLOW OVER SOUTHEAST IDAHO. MODELS
CONTINUE TO SHOW THIS UPPER LEVEL LOW TO MOVE NNE INTO CANADA BY
THURSDAY MORNING. EXPECT ISOLATED SHOWERS AND THUNDERSTORMS OVER
THE SOUTHEAST HIGHLANDS AND THE NORTHERN CENTRAL MOUNTAIN THIS
AFTERNOON. ADDITIONALLY...EXPECT BREEZY TO MODERATE WINDS ACROSS
THE AREA THIS AFTERNOON AS THE SURFACE PRESSURE GRADIENT TIGHTENS
WITH THE APPROACHING LOW AND ASSOCIATED COLD FRONT. WINDS LOOK TO
REMAIN JUST BELOW LAKE WIND ADVISORY LEVELS FOR THE AMERICAN FALLS
RESERVOIR BUT LOOK FOR LIGHT CHOP TO STILL DEVELOP OVER THE
RESERVOIR THIS AFTERNOON INTO EARLY EVENING. MODELS SHOW THE FIRST
PUSH OF COOL AIR TO REACH OUR WESTERN BORDERS BY THIS MORNING WITH
THE COLD FRONT COMPLETELY PUSHING THROUGH BY LATE AFTERNOON INTO
EARLY EVENING. EXPECT OVERALL DRY CONDITIONS THURSDAY AS HIGH
PRESSURE RIDGING STARTS TO BUILD INTO THE AREA. LOOK FOR A SLIGHT
CHANCE OF AFTERNOON MOUNTAIN SHOWERS AND THUNDERSTORMS FRIDAY
AFTERNOON AS MODELS SHOW SUB-TROPICAL MOISTURE AND INSTABILITY
MOVING INTO THE AREA. EXPECT WELL ABOVE AVERAGE TEMPERATURES FOR
OUR EASTERN AREAS TODAY AND NEAR AVERAGE TO SLIGHTLY BELOW AVERAGE
TEMPERATURES FOR ALL AREAS ON THURSDAY. TEMPERATURES WILL AGAIN
RISE ABOVE NORMAL BY FRIDAY. WYATT
LONG TERM...FRIDAY NIGHT THROUGH NEXT WEDNESDAY. SATURDAY LOOK
FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS FROM MOISTURE
AND INSTABILITY AHEAD OF ANOTHER UPPER LEVEL LOW. SUNDAY INTO
MONDAY BOTH MODELS CONTINUE TO SHOW SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS AS AN UPPER LEVEL LOW MOVES DIRECTLY OVER OUR
AREA. EXPECT AFTERNOON ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS ON TUESDAY AND WEDNESDAY FROM RESIDUAL MOISTURE AND
INSTABILITY FROM THE SLOW EXITING SYSTEM. EXPECT TEMPERATURES TO
DROP TO NEAR NORMAL TO SLIGHTLY BELOW NORMAL BY MONDAY BEFORE
RISING ABOVE NORMAL AGAIN ON TUESDAY AND WEDNESDAY. WYATT
AVIATION...A LOW PRESSURE SYSTEM WAS OBSERVED OVER THE OREGON COAST
EARLY THIS MORNING WITH A FAIRLY DRY SW FLOW NOTED DOWNSTREAM ACROSS
SE IDAHO. SATELLITE IMAGERY AND MODELS SUGGEST THAT SOME MID-LEVEL
PACIFIC MOISTURE WILL BECOME ENTRAINED INTO THE FLOW LIFTING NE
ACROSS THE AREA THIS AFTERNOON. THERE MIGHT BE ENOUGH MOISTURE AND
INSTABILITY THIS AFTERNOON TO SUPPORT ISOLATED THUNDERSTORM ACTIVITY
OVER THE SE HIGHLANDS. A FAIRLY STEEP SURFACE PRESSURE GRADIENT WAS
NOTED ACROSS SW IDAHO THIS MORNING BETWEEN A LOW OVER NW UTAH AND
HIGH PRESSURE MOUNTING ACROSS OREGON. THUS EXPECTING VFR SCT-BKN
MID-LEVEL CLOUDS ACROSS THE TERMINALS WITH BREEZY WINDS THIS
AFTERNOON AND CLEARING TONIGHT BEHIND A FRONTAL PASSAGE LATE THIS
AFTERNOON/EVENING. HUSTON
FIRE WEATHER...AN UPPER LEVEL LOW PRESSURE SYSTEM WAS POSITIONED
OVER THE OREGON COAST EARLY THIS MORNING AS A DRY SOUTHWEST FLOW
REMAINED OVER SOUTHEAST IDAHO. MODEL SOLUTIONS CONTINUE TO LIFT THE
LOW NORTH-NORTHEAST INTO WASHINGTON THIS AFTERNOON AND SOUTHERN
CANADA TONIGHT/THURSDAY WITH LITTLE IN THE WAY OF ANY SIGNIFICANT
MOISTURE OR CONVECTION ANTICIPATED ACROSS THE AREA. A SURFACE LOW
WAS POSITIONED OVER NW UTAH EARLY THIS MORNING WITH A FAIRLY STIFF
SURFACE PRESSURE GRADIENT EXTENDING FROM MISSOULA TO WINNEMUCCA.
MODELS SUGGEST THAT AS THE UPPER LEVEL LOW LIFTS NNE TODAY AN
INITIAL COLD FRONTAL PUSH WILL EXTEND INTO THE MAGIC
VALLEY/POCATELLO REGION THIS MORNING FOLLOWED BY A STRONGER PUSH
LATE THIS AFTERNOON/EVENING AS THE COLDER AIR ADVANCES INTO THE
REGION BEHIND THE EXITING UPPER LOW. THUS EXPECTING BREEZY AFTERNOON
WINDS ACROSS THE MAGIC VALLEY AND THROUGHOUT THE INL AND CENTRAL
MOUNTAINS TODAY. A FAIRLY DRY SOUTHWEST FLOW WILL LINGER OVER THE
REGION THURSDAY AS THE UPPER LOW CONTINUES TO LIFT NE THROUGH
CANADA. THE MODELS REMAIN STEADFAST IN SHOWING A LOW PRESSURE SYSTEM
DEVELOPING ALONG THE NW COAST FRIDAY WITH A PUSH OF SUB-TROPICAL
MOISTURE WORKING NORTH THROUGH COLORADO INTO WYOMING FOR SOME MODEST
SUPPORT FOR SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE EASTERN
MOUNTAINS NEAR THE WYOMING BORDER AND ISOLATED ACTIVITY OVER THE
CENTRAL AND SOUTHERN MOUNTAINS UNDER MARGINALLY UNSTABLE CONDITIONS.
BY SATURDAY AND SUNDAY...THE LOW IS EXPECTED TO GRADUALLY ADVANCE
INTO THE GREAT BASIN WITH SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS DEVELOPING OVER THE REGION. UNSETTLED CONDITIONS WILL
LINGER ACROSS THE REGION MONDAY AND TUESDAY AS THE LOW IS SLOW TO
EXIT THE AREA. HUSTON
HYDROLOGY...THE TETON RIVER AT ST. ANTHONY IS STILL RISING
BECAUSE OF WARM TEMPERATURES CREATING ACCELERATED SNOW MELT. THE
RIVER IS EXPECTED TO REACH BANKFULL STAGE THIS EVENING AND THEN
CONTINUE TO SLOWLY RISE FOR THE NEXT FEW DAYS. PLEASE SEE THE NWS
RIVER STATEMENT FOR MORE DETAIL. WYATT
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
241 AM CDT WED MAY 28 2014
.DISCUSSION...
1022 PM CDT
SCATTERED STORMS ACROSS FAR NORTH CENTRAL IL WILL LIKELY CONTINUE
TO FESTER EASTWARD THROUGH EARLY OVERNIGHT. THESE HAVE A LITTLE
MID-LEVEL SUPPORT FROM THE UPPER LOW ACROSS SOUTHWEST WI. OFF OF
THE OUTFLOWS FROM THESE STORMS...A FEW NEW CELLS MAY
SPARK...PRIMARILY SOUTH TOWARD LEE...OGLE...AND DEKALB COUNTIES
WHERE THE AIR MASS IS A LITTLE MORE UNTAPPED.
WEBCAMS NEAR THE LAKE FRONT ARE MAINLY NOT SHOWING ANY
FOG...HOWEVER THE MARINE LAYER IS CLEARING MAKING INROADS BASED ON
LOW CIGS AND TEMPERATURE TRENDS IN FAR NORTHEAST IL. SO WOULD NOT
BE SURPRISED TO SEE DENSE FOG ADVECTING ONSHORE SOON. THIS COULD
STICK AROUND INTO THE BEGINNING PARTS OF THE MORNING RUSH HOUR.
MTF
//PREV DISCUSSION...
321 PM CDT
THERE WILL BE SEVERAL FORECAST CHALLENGES FOR THE NEXT SEVERAL
DAYS...INCLUDING THUNDERSTORM CHANCES AND A THE PROGRESSION OF A
BACK DOOR COLD FRONT FOR THE SHORT TERM AND TEMPERATURE TRENDS WITH
NEAR-DAILY LAKE BREEZES AS WELL AS CHANCES FOR THUNDERSTORMS...
PARTICULARLY DURING THE EXTENDED FORECAST PERIOD.
FOR THE REMAINDER OF THE AFTERNOON AND INTO THIS EVENING...WILL NEED
TO CLOSELY MONITOR THUNDERSTORM TRENDS OVER THE AREA AS THE REGION
IS UNDER A WARM...HUMID AIRMASS. THE MAIN TRIGGERS FOR
THUNDERSTORMS WILL BE A PAIR OF WEAK SHORTWAVES OVER THE AREA AS
WELL AS THE BACK DOOR COLD FRONT TRACKING PUSHING THROUGH SERN WI AT
ISSUANCE TIME. THIS AFTERNOON...THERE IS LITTLE ORGANIZATION TO THE
THUNDERSTORM ACTIVITY WHICH IS MOSTLY STILL OVER SRN
WISCONSIN...WITH A FEW ISOLD CELLS OVER NRN IL. EXPECT THAT
THUNDERSTORMS COULD BECOME A BIT MORE ORGANIZED AS THE COLD FRONT
PUSHES INTO NRN IL LATE THIS AFTERNOON AND EARLY THIS EVENING. WITH
NO SGFNT SHEAR...THE SEVERE POTENTIAL IS LOW...BUT WITH PWATS
APPROACHING 1.5 ON THE 12Z DVN/ILX SOUNDINGS...BRIEF HEAVY DOWNPOURS
MAY ACCOMPANY SOME OF THE STRONGER CELLS. THE OTHER CONCERN THIS
EVENING WILL BE THE TEMPERATURE TREND ASSOCIATED WITH THE PASSAGE OF
THE BACK DOOR COLD FRONT AND THE ASSOCIATED IMPACT ON THUNDER
POTENTIAL. WATCHING THE FRONT WORK DOWN THE WEST SHORE OF LAKE
MICHIGAN...TEMPERATURES MAY DROP 20 DEGREES OR MORE WITH TEMPS IN
THE LOWER 80S AHEAD OF THE FRONT AND THE MIDDLE 50S NEAR THE
LAKEFRONT TO THE MIDDLE 60S INLAND. DEPENDING ON THE EXACT TIMING
OF THE FROPA...IF IT OCCURS NEAR OR SHORTLY AFTER THE TIME OF MAX
HEATING...TEMPERATURES COULD DROP ALMOST 30 DEGREES ALONG THE
ILLINOIS LAKEFRONT. WHILE THE COLD FRONT SHOULD ACT AS A FOCUSING
MECHANISM FOR MORE ORGANIZED THUNDERSTORM ACTIVITY LATE THIS
AFTERNOON AND EARLY THIS EVENING...THERE WILL STILL BE SOME THUNDER
POTENTIAL AS THE FRONT SLOWLY DROPS SOUTH ACROSS THE CWA. THUNDER
POTENTIAL SHOULD DROP OFF DURING THE EARLY OVERNIGHT PERIOD...BUT
HAVE HUNG ON TO SLIGHT CHANCE POPS OVER THE NRN PORTIONS OF THE CWA
INTO EARLY TOMORROW MORNING...MORE IN DEFERENCE TO SOME
DISORGANIZED SHORT WAVE ENERGY OVER THE AREA RATHER THAN THE FRONT.
WILL KEEP SOME LIKELY POPS OVER THE FAR SRN PORTIONS OF THE CWA
TOMORROW WITH THE COLD STALLING OUT OVER CENTRAL ILLINOIS.
AS FOR TEMPERATURES...WITH HIGH PRESSURE SITTING OVER THE UPPER
GREAT LAKES TO HUDSON BAY AND WEAK TROUGHING OVER THE OHIO VALLEY
REMAINING RELATIVELY STATIONARY THROUGH SATURDAY...SFC FLOW OVER THE
AREA WILL GENERALLY BE OFF OF THE LAKE. THE MODELS ARE ALL
RELATIVELY CONSISTENT ON THE IDEA OF BUILDING AN UPPER RIDGE OVER
THE UPPER MIDWEST AND INTO THE WESTERN GREAT LAKES...A GENERAL
WARMING TREND WILL SET UP OVER THE CWA. HOWEVER... THE SFC PRESSURE
PATTERN WOULD KEEP GENERALLY NORTHEASTERLY TO NORTHEASTERLY FLOW IN
PLACE. LAKE MICHIGAN SFC WATER TEMPERATURES REMAIN RATHER LOW FOR
LATE MAY...WITH COASTAL WATER TEMPERATURES IN THE UPPER 40S TO
MIDDLE 50S AND THE SOUTH MID-LAKE BUOY STILL INDICATING WATER
TEMPERATURES IN THE UPPER 30S. SO...LAKEFRONT LOCATIONS WILL REMAIN
SIGNIFICANTLY COOLER THAN INLAND AREAS. WITH LINGERING CLOUD COVER
AND PCPN FOLLOWING THE FROPA...WEDNESDAY WILL LIKELY BE THE COOLEST
DAY OF THE PERIOD...WITH HIGHS IN THE MIDDLE TO UPPER 70S OVER MUCH
OF THE CWA...WHILE THE LAKEFRONT REMAINS IN THE UPPER 50S TO AROUND
60. FRIDAY SHOULD BE THE WARMEST DAY OF THE PERIOD AS THE CENTER OF
THE UPPER HIGH MOVES OVER THE UPPER MISSISSIPPI VALLEY...WITH INLAND
TEMPERATURES REACHING INTO THE UPPER 80S AND THE LAKEFRONT ONLY IN
THE MIDDLE 60S.
BY THE WEEKEND...THE LONGER RANGE GUIDANCE IS INDICATING SOME SHORT
WAVE ENERGY LIFTING OUT OF THE SOUTHERN ROCKIES AND INTO THE CENTRAL
PLAINS. EVENTUALLY THROUGH THE WEEKEND...THE SHORTWAVE ENERGY WILL
TRY TO BREAK DOWN THE UPPER RIDGE AND BRING THE NEXT SIGNIFICANT
CHANCE FOR SHOWERS AND THUNDERSTORMS TO THE AREA. GENERAL RIDGING
WILL KEEP HIGH TEMPERATURES IN THE LOWER 80S THROUGH THE EXTENDED
FORECAST PERIOD...THE WEEKEND INTO EARLY NEXT WEEK. ALSO...SFC HIGH
PRESSURE SHOULD SET UP OVER NEW ENGLAND WHILE GENERAL SFC TROUGHING
DEVELOPS OVER THE CENTRAL PLAINS. THIS WILL FINALLY BRING AN END TO
THE ONSHORE FLOW PATTERN AND THE LAKEFRONT LOCATIONS WILL FINALLY
WARM UP WITH THE REST OF THE CWA...AND TEMPERATURES IN THE 80S WILL
SPREAD UP TO THE LAKE FRONT. THERE SHOULD BE PERIODIC CHANCES FOR
SHOWERS AND THUNDERSTORMS FROM SUNDAY...THROUGH THE END OF THE
PERIOD...TUESDAY...AS THE GULF OF MEXICO OPENS UP IN ADVANCE OF
CENTRAL PLAINS TROUGHING MID LEVEL SHORT WAVE ENERGY OVERTOPS THE
UPPER RIDGE.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* IFR AND LOWER CIGS AT TIMES OVERNIGHT LIFTING/SCATTERING OUT MID
WEDNESDAY MORNING AND BECOMING VFR.
* RETURN OF MVFR CIGS WEDNESDAY NIGHT.
BMD
//DISCUSSION...UPDATED 06Z...
A COLD FRONT HAS SWEPT ACROSS THE REGION WITH NORTHEAST FLOW IN
PLACE THROUGH THE FORECAST PERIOD. A FEW FESTERING SHOWERS AND
THUNDERSTORMS ARE MOVING EAST ACROSS NORTHEASTERN ILLINOIS AND WILL
LIKELY BRING A BRIEF ROUND OF TSRA TO THE TERMINALS THIS EVENING.
ACTIVITY HAS SHOWN SIGNS OF WEAKENING THOUGH AND EXPECT THIS TREND
TO CONTINUE AS THE THUNDERSTORMS MOVE INTO WORKED OVER AIR AND
OUTFLOW RUSHES AHEAD. IN FACT...WINDS HAVE TURNED NORTHWESTERLY
BEHIND THE OUTFLOW AT ORD...BUT EXPECT WINDS TO GRADUALLY VEER BACK
TO THE NORTHEAST OVER THE NEXT HOUR OR TWO. LOWER CIGS HAVE BEGUN TO
OVERSPREAD THE REGION BEHIND THE FRONT WITH NUMEROUS SITES NEAR THE
LAKE REPORTING LIFR CONDITIONS. EXPECT THIS TO CONTINUE TO SPREAD
OVERNIGHT...THEN CIGS SHOULD BEGIN TO LIFT AND SCATTER OUT SOMETIME
WEDNESDAY MORNING. THERE IS SOME MODEST INSTABILITY THAT DEVELOPS
WEDNESDAY AFTERNOON AND CANNOT COMPLETELY RULE OUT A FEW SHOWERS OR
THUNDERSTORMS...BUT CHANCES WILL BE BETTER SOUTH OF I-80 NEAR THE
FRONT.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN IFR/LIFR CIGS OVERNIGHT...MEDIUM CONFIDENCE
IN LIFT/SCATTERING BACK TO IFR BY MID TO LATE WED MORNING.
* MEDIUM CONFIDENCE IN WINDS.
* LOW CONFIDENCE IN TSRA IMPACTING TERMINALS AGAIN WEDNESDAY
AFTERNOON/EVENING.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY-SATURDAY...EAST FLOW LIKELY.
SUNDAY-MONDAY...CHC OF TSRA.
MTF
&&
.MARINE...
241 AM CDT
A COLD FRONT HAS CLEARED SOUTHERN LAKE MICHIGAN THIS MORNING WITH
PRIMARILY MODEST NORTH WINDS IN PLACE ACROSS THE LAKE AWAY FROM THE
INFLUENCE OF THUNDERSTORMS AND REMNANT OUTFLOWS FROM THUNDERSTORMS.
FOG CONTINUES ACROSS MAINLY SOUTHERN PORTIONS OF THE LAKE AND THE
DRIER NORTH FLOW SHOULD SLOWLY ERODE AND PUSH THE FOG FURTHER SOUTH.
IT DOES APPEAR THE FOG WILL LINGER A LITTLE LONGER THAN EXPECTED SO
WILL EXTEND THE ADVISORY...BUT EXPECT MOST OF THE FOG TO CLEAR OUT
BY MID TO LATE THIS AFTERNOON. HIGH PRESSURE IS IN PLACE NEAR HUDSON
BAY WITH RIDGING EXTENDING SOUTH INTO THE GREAT LAKES. THIS WILL
REMAIN THE CASE THROUGH THE REMAINDER OF THE WEEK WITH LIGHT NORTH
TO NORTHEAST FLOW. DURING THE AFTERNOON...WINDS SHOULD BE LIGHT
ENOUGH FOR LAKE BREEZES TO FORM TURNING WINDS ONSHORE IN SOME OF
THE NEARSHORE WATERS.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-
LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 PM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
228 AM CDT Wed May 28 2014
.DISCUSSION...
ISSUED 225 AM CDT Wed May 28 2014
Regional radar imagery fairly quiet early this morning, although a
few showers continue to percolate between Macomb and Peoria as of
2 am. A weak boundary was present but hard to detect on surface
observations, but is roughly along a Quincy to Kankakee line.
However, a more prominent cold front was located from just north
of Detroit into southern Wisconsin, with a boundary extending
southwest into Kansas. The ever-present cutoff upper low has now
made it to the Arklatex region, and shows up nicely on infrared as
well as water vapor imagery.
The diurnal trend for showers and storms will still be in place
for another day or so. A couple days of dry weather actually are
possible before the showers and storms return early next week. The
summer like temperatures will continue for several more days,
although Friday and Saturday are likely to be somewhat less humid.
SHORT TERM...Today through Friday:
The cold front will be settling southward today, and should be
near I-70 by midnight. Increasing lift toward midday should allow
for the next round of showers and storms to blossom, persisting
into the afternoon. North half of the forecast area most likely to
see the most numerous storms, while the southeast remains rather
scattered with the front not arriving until evening. Shear values
remain weak, only around 10 knots or so from 0-6km, although
instability is more modest with CAPE`s reaching 1000-1500 J/kg.
Severe weather chances remain low, but we have seen some isolated
wind gusts/damage over the last couple days in a similar
environment. Latest SPC Day1 outlook does show low 5%
probabilities of severe winds/damage across the eastern CWA.
High pressure will extend southwest from the Great Lakes over the
next couple days, gradually shoving the threat for diurnal
convection further south. Have kept the northern third of the
forecast area dry for Thursday and Friday, with some PoP`s further
south on Thursday. Most of the models have the entire forecast
area dry by Friday, but the ECMWF and GFS continue to feature
showers and storms along the periphery of the high just outside of
our forecast area, so have kept some 20% PoP`s along the southwest
edge of the CWA on Friday.
LONG TERM...Saturday through Tuesday:
A nice start to the weekend is on tap with the upper ridge
basically overhead, but this continues to be progged to break down
through the period. The first part of Sunday is also likely to be
dry as well. However, showers and storms will increase as a warm
front sets up from the central Plains into Wisconsin. As this will
be roughly parallel to the upper flow for a couple days, the rain
chances will linger into mid week.
Geelhart
&&
.AVIATION...
ISSUED 1143 PM CDT Tue May 27 2014
A narrow corridor of convection from Decatur to Champaign and
Danville has begun to diminish in coverage and intensity and
advance toward Indiana between 04z-05z. A line of spotty showers
SW of there between SPI and DEC were diminishing quickly as well.
The remainder of the night should remain dry for the terminal
sites, based on satellite, radar, and the latest 4km HRRR output.
The next wave of showers and storms should primarily hold off
until afternoon on Wednesday. PIA and BMI could see storms in the
vicinity as early as 18z, as a weak cold front arrives from the
north. Storm chances would progressively advance toward the
southern terminal sites of SPI and DEC by 20z. MVFR conditions
will be possible during any heavy downpours for reduced
visibility. Ceilings should remain VFR even during storms.
Increasing low level instability could allow for a few storms
tomorrow afternoon to produce wind gusts of 40-50 mph and small
hail.
The rest of tonight, winds should remain light southwest or calm
through sunrise. Wind directions will become variable as the cold
front arrives tomorrow, then winds should become east-northeast
after the front passes to the south of each TAF site. The weak
pressure gradient should help keep wind speeds at 10kt or less for
the entire TAF period, outside of thunderstorms.
Shimon
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1228 AM CDT WED MAY 28 2014
.DISCUSSION...
1022 PM CDT
SCATTERED STORMS ACROSS FAR NORTH CENTRAL IL WILL LIKELY CONTINUE
TO FESTER EASTWARD THROUGH EARLY OVERNIGHT. THESE HAVE A LITTLE
MID-LEVEL SUPPORT FROM THE UPPER LOW ACROSS SOUTHWEST WI. OFF OF
THE OUTFLOWS FROM THESE STORMS...A FEW NEW CELLS MAY
SPARK...PRIMARILY SOUTH TOWARD LEE...OGLE...AND DEKALB COUNTIES
WHERE THE AIR MASS IS A LITTLE MORE UNTAPPED.
WEBCAMS NEAR THE LAKE FRONT ARE MAINLY NOT SHOWING ANY
FOG...HOWEVER THE MARINE LAYER IS CLEARING MAKING INROADS BASED ON
LOW CIGS AND TEMPERATURE TRENDS IN FAR NORTHEAST IL. SO WOULD NOT
BE SURPRISED TO SEE DENSE FOG ADVECTING ONSHORE SOON. THIS COULD
STICK AROUND INTO THE BEGINNING PARTS OF THE MORNING RUSH HOUR.
MTF
//PREV DISCUSSION...
321 PM CDT
THERE WILL BE SEVERAL FORECAST CHALLENGES FOR THE NEXT SEVERAL
DAYS...INCLUDING THUNDERSTORM CHANCES AND A THE PROGRESSION OF A
BACK DOOR COLD FRONT FOR THE SHORT TERM AND TEMPERATURE TRENDS WITH
NEAR-DAILY LAKE BREEZES AS WELL AS CHANCES FOR THUNDERSTORMS...
PARTICULARLY DURING THE EXTENDED FORECAST PERIOD.
FOR THE REMAINDER OF THE AFTERNOON AND INTO THIS EVENING...WILL NEED
TO CLOSELY MONITOR THUNDERSTORM TRENDS OVER THE AREA AS THE REGION
IS UNDER A WARM...HUMID AIRMASS. THE MAIN TRIGGERS FOR
THUNDERSTORMS WILL BE A PAIR OF WEAK SHORTWAVES OVER THE AREA AS
WELL AS THE BACK DOOR COLD FRONT TRACKING PUSHING THROUGH SERN WI AT
ISSUANCE TIME. THIS AFTERNOON...THERE IS LITTLE ORGANIZATION TO THE
THUNDERSTORM ACTIVITY WHICH IS MOSTLY STILL OVER SRN
WISCONSIN...WITH A FEW ISOLD CELLS OVER NRN IL. EXPECT THAT
THUNDERSTORMS COULD BECOME A BIT MORE ORGANIZED AS THE COLD FRONT
PUSHES INTO NRN IL LATE THIS AFTERNOON AND EARLY THIS EVENING. WITH
NO SGFNT SHEAR...THE SEVERE POTENTIAL IS LOW...BUT WITH PWATS
APPROACHING 1.5 ON THE 12Z DVN/ILX SOUNDINGS...BRIEF HEAVY DOWNPOURS
MAY ACCOMPANY SOME OF THE STRONGER CELLS. THE OTHER CONCERN THIS
EVENING WILL BE THE TEMPERATURE TREND ASSOCIATED WITH THE PASSAGE OF
THE BACK DOOR COLD FRONT AND THE ASSOCIATED IMPACT ON THUNDER
POTENTIAL. WATCHING THE FRONT WORK DOWN THE WEST SHORE OF LAKE
MICHIGAN...TEMPERATURES MAY DROP 20 DEGREES OR MORE WITH TEMPS IN
THE LOWER 80S AHEAD OF THE FRONT AND THE MIDDLE 50S NEAR THE
LAKEFRONT TO THE MIDDLE 60S INLAND. DEPENDING ON THE EXACT TIMING
OF THE FROPA...IF IT OCCURS NEAR OR SHORTLY AFTER THE TIME OF MAX
HEATING...TEMPERATURES COULD DROP ALMOST 30 DEGREES ALONG THE
ILLINOIS LAKEFRONT. WHILE THE COLD FRONT SHOULD ACT AS A FOCUSING
MECHANISM FOR MORE ORGANIZED THUNDERSTORM ACTIVITY LATE THIS
AFTERNOON AND EARLY THIS EVENING...THERE WILL STILL BE SOME THUNDER
POTENTIAL AS THE FRONT SLOWLY DROPS SOUTH ACROSS THE CWA. THUNDER
POTENTIAL SHOULD DROP OFF DURING THE EARLY OVERNIGHT PERIOD...BUT
HAVE HUNG ON TO SLIGHT CHANCE POPS OVER THE NRN PORTIONS OF THE CWA
INTO EARLY TOMORROW MORNING...MORE IN DEFERENCE TO SOME
DISORGANIZED SHORT WAVE ENERGY OVER THE AREA RATHER THAN THE FRONT.
WILL KEEP SOME LIKELY POPS OVER THE FAR SRN PORTIONS OF THE CWA
TOMORROW WITH THE COLD STALLING OUT OVER CENTRAL ILLINOIS.
AS FOR TEMPERATURES...WITH HIGH PRESSURE SITTING OVER THE UPPER
GREAT LAKES TO HUDSON BAY AND WEAK TROUGHING OVER THE OHIO VALLEY
REMAINING RELATIVELY STATIONARY THROUGH SATURDAY...SFC FLOW OVER THE
AREA WILL GENERALLY BE OFF OF THE LAKE. THE MODELS ARE ALL
RELATIVELY CONSISTENT ON THE IDEA OF BUILDING AN UPPER RIDGE OVER
THE UPPER MIDWEST AND INTO THE WESTERN GREAT LAKES...A GENERAL
WARMING TREND WILL SET UP OVER THE CWA. HOWEVER... THE SFC PRESSURE
PATTERN WOULD KEEP GENERALLY NORTHEASTERLY TO NORTHEASTERLY FLOW IN
PLACE. LAKE MICHIGAN SFC WATER TEMPERATURES REMAIN RATHER LOW FOR
LATE MAY...WITH COASTAL WATER TEMPERATURES IN THE UPPER 40S TO
MIDDLE 50S AND THE SOUTH MID-LAKE BUOY STILL INDICATING WATER
TEMPERATURES IN THE UPPER 30S. SO...LAKEFRONT LOCATIONS WILL REMAIN
SIGNIFICANTLY COOLER THAN INLAND AREAS. WITH LINGERING CLOUD COVER
AND PCPN FOLLOWING THE FROPA...WEDNESDAY WILL LIKELY BE THE COOLEST
DAY OF THE PERIOD...WITH HIGHS IN THE MIDDLE TO UPPER 70S OVER MUCH
OF THE CWA...WHILE THE LAKEFRONT REMAINS IN THE UPPER 50S TO AROUND
60. FRIDAY SHOULD BE THE WARMEST DAY OF THE PERIOD AS THE CENTER OF
THE UPPER HIGH MOVES OVER THE UPPER MISSISSIPPI VALLEY...WITH INLAND
TEMPERATURES REACHING INTO THE UPPER 80S AND THE LAKEFRONT ONLY IN
THE MIDDLE 60S.
BY THE WEEKEND...THE LONGER RANGE GUIDANCE IS INDICATING SOME SHORT
WAVE ENERGY LIFTING OUT OF THE SOUTHERN ROCKIES AND INTO THE CENTRAL
PLAINS. EVENTUALLY THROUGH THE WEEKEND...THE SHORTWAVE ENERGY WILL
TRY TO BREAK DOWN THE UPPER RIDGE AND BRING THE NEXT SIGNIFICANT
CHANCE FOR SHOWERS AND THUNDERSTORMS TO THE AREA. GENERAL RIDGING
WILL KEEP HIGH TEMPERATURES IN THE LOWER 80S THROUGH THE EXTENDED
FORECAST PERIOD...THE WEEKEND INTO EARLY NEXT WEEK. ALSO...SFC HIGH
PRESSURE SHOULD SET UP OVER NEW ENGLAND WHILE GENERAL SFC TROUGHING
DEVELOPS OVER THE CENTRAL PLAINS. THIS WILL FINALLY BRING AN END TO
THE ONSHORE FLOW PATTERN AND THE LAKEFRONT LOCATIONS WILL FINALLY
WARM UP WITH THE REST OF THE CWA...AND TEMPERATURES IN THE 80S WILL
SPREAD UP TO THE LAKE FRONT. THERE SHOULD BE PERIODIC CHANCES FOR
SHOWERS AND THUNDERSTORMS FROM SUNDAY...THROUGH THE END OF THE
PERIOD...TUESDAY...AS THE GULF OF MEXICO OPENS UP IN ADVANCE OF
CENTRAL PLAINS TROUGHING MID LEVEL SHORT WAVE ENERGY OVERTOPS THE
UPPER RIDGE.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* IFR AND LOWER CIGS AT TIMES OVERNIGHT LIFTING/SCATTERING OUT MID
WEDNESDAY MORNING AND BECOMING VFR.
* RETURN OF MVFR CIGS WEDNESDAY NIGHT.
BMD
//DISCUSSION...UPDATED 06Z...
A COLD FRONT HAS SWEPT ACROSS THE REGION WITH NORTHEAST FLOW IN
PLACE THROUGH THE FORECAST PERIOD. A FEW FESTERING SHOWERS AND
THUNDERSTORMS ARE MOVING EAST ACROSS NORTHEASTERN ILLINOIS AND WILL
LIKELY BRING A BRIEF ROUND OF TSRA TO THE TERMINALS THIS EVENING.
ACTIVITY HAS SHOWN SIGNS OF WEAKENING THOUGH AND EXPECT THIS TREND
TO CONTINUE AS THE THUNDERSTORMS MOVE INTO WORKED OVER AIR AND
OUTFLOW RUSHES AHEAD. IN FACT...WINDS HAVE TURNED NORTHWESTERLY
BEHIND THE OUTFLOW AT ORD...BUT EXPECT WINDS TO GRADUALLY VEER BACK
TO THE NORTHEAST OVER THE NEXT HOUR OR TWO. LOWER CIGS HAVE BEGUN TO
OVERSPREAD THE REGION BEHIND THE FRONT WITH NUMEROUS SITES NEAR THE
LAKE REPORTING LIFR CONDITIONS. EXPECT THIS TO CONTINUE TO SPREAD
OVERNIGHT...THEN CIGS SHOULD BEGIN TO LIFT AND SCATTER OUT SOMETIME
WEDNESDAY MORNING. THERE IS SOME MODEST INSTABILITY THAT DEVELOPS
WEDNESDAY AFTERNOON AND CANNOT COMPLETELY RULE OUT A FEW SHOWERS OR
THUNDERSTORMS...BUT CHANCES WILL BE BETTER SOUTH OF I-80 NEAR THE
FRONT.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN IFR/LIFR CIGS OVERNIGHT...MEDIUM CONFIDENCE
IN LIFT/SCATTERING BACK TO IFR BY MID TO LATE WED MORNING.
* MEDIUM CONFIDENCE IN WINDS.
* LOW CONFIDENCE IN TSRA IMPACTING TERMINALS AGAIN WEDNESDAY
AFTERNOON/EVENING.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY-SATURDAY...EAST FLOW LIKELY.
SUNDAY-MONDAY...CHC OF TSRA.
MTF
&&
.MARINE...
253 PM CDT
PRIMARY MARINE CONCERN IN THE NEAR TERM IS DURATION OF DENSE FOG
OVER THE SOUTHERN HALF OF THE LAKE AND OVER THE NEARSHORE WATERS
INTO THIS EVENING. A COLD FRONT IS DROPPING SOUTH ACROSS THE
SOUTHERN PORTION OF THE LAKE THIS AFTERNOON...BUT DRIER AIR IS ONLY
SLOWLY PUSHING IN FROM THE NORTH. BASED ON WEBCAMS AND SFC OBS OVER
THE CENTRAL PORTION OF THE LAKE...ITS LIKELY THAT THERE IS DENSE FOG
THAT WILL OVERSPREAD THE FAR SOUTHERN PORTION OF THE LAKE AND THE
NEARSHORE BEHIND THE FRONT. PRESENCE OF THUNDERSTORMS MAY RESULT IN
AREAS OF VARIABLE VISIBILITY...BUT OVERALL TREND SHOULD BE FAIRLY
SOLID DENSE FOG. HAVE EXTENDED THE DENSE FOG ADVISORY FOR THE SOUTH
HALF UNTIL 9Z AND ISSUED AN ADVISORY FOR THE IL AND NW IN NEARSHORE
UNTIL 9Z.
MODERATE NORTHERLY AND NORTHEAST WINDS WILL BE IN PLACE TONIGHT
THROUGH WEDNESDAY. THEN EXPECT LIGHTER WINDS CONTROLLED BY LAKE
BREEZE INFLUENCES NEAR THE SHORES WEDNESDAY NIGHT THROUGH FRIDAY
NIGHT WITH HIGH PRESSURE OVER THE LAKE. SOUTHERLY WINDS WILL RETURN
SATURDAY AND COULD INCREASE TO UP TO 15 TO 25 KT ON SUNDAY AS THE
HIGH PRESSURE SLIDES EAST AND LOW PRESSURE APPROACHES FROM THE WEST.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-
LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-
LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 4 AM WEDNESDAY.
&&
$$
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WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
1143 PM CDT Tue May 27 2014
.DISCUSSION...
ISSUED 900 PM CDT Tue May 27 2014
Diurnal stabilization has caused the majority of showers/storms to
dissipate. A few showers or storms have continued to bubble up on
outflow boundaries from earlier convection, but coverage is very
sparse and mainly along I-72 northeast of Decatur. Will keep
slight chance PoPs in the forecast for the overnight, but most
areas will remain dry.
Temps will remain on the warm side again tonight as lows bottom
out in the mid 60s. Humidity levels will be higher as dewpoints
climb into the upper 50s to around 60. The weak pressure gradient
across the area will keep winds light from the southwest or
variable.
The only updates this evening were to the weather and PoP grids.
The latest info will be sent shortly.
Shimon
&&
.AVIATION...
ISSUED 1143 PM CDT Tue May 27 2014
A narrow corridor of convection from Decatur to Champaign and
Danville has begun to diminish in coverage and intensity and
advance toward Indiana between 04z-05z. A line of spotty showers
SW of there between SPI and DEC were diminishing quickly as well.
The remainder of the night should remain dry for the terminal
sites, based on satellite, radar, and the latest 4km HRRR output.
The next wave of showers and storms should primarily hold off
until afternoon on Wednesday. PIA and BMI could see storms in the
vicinity as early as 18z, as a weak cold front arrives from the
north. Storm chances would progressively advance toward the
southern terminal sites of SPI and DEC by 20z. MVFR conditions
will be possible during any heavy downpours for reduced
visibility. Ceilings should remain VFR even during storms.
Increasing low level instability could allow for a few storms
tomorrow afternoon to produce wind gusts of 40-50 mph and small
hail.
The rest of tonight, winds should remain light southwest or calm
through sunrise. Wind directions will become variable as the cold
front arrives tomorrow, then winds should become east-northeast
after the front passes to the south of each taf site. The weak
pressure gradient should help keep wind speeds at 10kt or less for
the entire taf period, outside of thunderstorms.
Shimon
&&
.PREV DISCUSSION...
ISSUED 258 PM CDT Tue May 27 2014
Central and southeast Illinois continue to see another warm and
humid summer-like day today, along with isolated-scattered,
diurnally driven, showers and thunderstorms. This pattern is
likely to hold through Thursday, with slightly cooler and less
humid conditions expected to end the week. Friday and Saturday also
stand the best chance of being rain free across the area out of
the next seven days.
Main forecast concerns revolve around rainfall chances and amounts
through Thursday under current weather regime, as well as to start
next week with the arrival of a stronger system/frontal boundary.
SHORT TERM...Tonight through Thursday: Spotty showers/storms
continue to become more numerous with the heating of the day this
afternoon, much like yesterday, and this trend should continue
until diurnal instability wanes this evening. However, the
coverage should remain greatest outside of the forecast area,
closer to the better forcing associated with a weak circulation
centered over southeast Minnesota, and a much larger/stronger
upper low that has been nearly stalled over the southern Plains.
The weak upper low from Minnesota, as well as some additional
energy topping the mean central U.S. ridge, will help to slowly
sink a weak cold front into/through the forecast area for
Wednesday into Thursday. This energy/front should provide a little
greater coverage of showers and storms starting tomorrow, although
that is not saying much considering how minimal the coverage has
been the past couple of days.
While the arrival of the weak front and upper energy may help the
convection to sustain into the nighttime hours a little more than
the past few days, the bulk of the showers/storms should remain
diurnally driven. However, severe weather does not appear likely.
Instability values (moderate) and shear profiles (very weak)
should remain similar to those we have already seen this week.
LONG TERM...Friday through Tuesday: The remnants of the surface
boundary settle south of the area for Friday into Saturday, with
upper ridging building strength aloft. This scenario should be
accompanied by drier and slightly cooler weather.
A stronger system will top the mean ridge to start next week,
dropping a cold front into the area. This front should be
accompanied by more widespread showers/storms than we have
seen/will see for much of this week. Models continue to disagree
with the timing and ultimate destination of this frontal boundary,
and these disagreements make it difficult to be too specific on
PoPs at this time.
BAK
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
516 PM EDT WED MAY 28 2014
.SYNOPSIS...
ISSUED AT 516 PM EDT WED MAY 28 2014
A FRONTAL BOUNDARY IS EXPECTED SHIFT SOUTH OUT OF THE AREA
TONIGHT...BRINGING AN END TO SHOWERS AND THUNDERSTORMS. HIGH
PRESSURE WILL THEN BUILD IN FOR THE END OF THE WEEK AND INTO THE
START OF THE WEEKEND. LOWS TONIGHT WILL RANGE FROM THE 50S NORTH
TO LOW 60S SOUTH WITH HIGHS ON THURSDAY AROUND 80 DEGREES EXCEPT
FOR NEAR LAKE MICHIGAN WHICH WILL BE IN THE 70S.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 336 PM EDT WED MAY 28 2014
LOOSELY DEFINED "COLD" FRONT...MORE ACCURATELY DESCRIBED AS A WEAK
SURFACE PRESSURE TROUGH WITH A MODEST MOISTURE/DENSITY
GRADIENT...CONTINUES TO SLOWLY PUSH SOUTH ACROSS THE AREA AT PRESS
TIME. AS PREVIOUSLY NOTED...VERY LITTLE SYNOPTIC SUPPORT ALONG THIS
FRONT WITH JUST A VERY WEAK VORTICITY LOBE WINDING DOWN ACROSS THE
REGION. SHOWERS AND THUNDERSTORMS BEING DRIVEN BY SUBTLE CONVERGENCE
ALONG OLD OUTFLOW/DIFFERENTIAL HEATING BOUNDARIES IN A MOIST AND
MARGINALLY UNSTABLE AIRMASS. EARLY DAY INSOLATION ALLOWED FOR A
DECENT RISE IN MLCAPE VALUES ACROSS OUR SOUTHERN COUNTIES WHILE FAR
NORTHERN ZONES REMAIN LARGELY CAPPED AND STABLE. NUMEROUS SHOWERS
AND THUNDERSTORMS HAVE THEREFORE DEVELOPED IN OUR SOUTHERN CWA AS
EXPECTED. LACK OF APPRECIABLE SHEAR AND/OR CLEAR FORCING MECHANISM
WILL CONTINUE TO SUPPORT PULSE/MULTICELLULAR MODE THROUGH THE
EVENING. AN ISOLATED WET MICROBURST MAY BE POSSIBLE ONCE AGAIN BUT
THREAT FOR MORE WIDESPREAD SEVERE WEATHER IS VERY LOW. HEAVY RAIN IS
STILL THE MAIN THREAT WITH HIGH PW VALUES...WEAK FLOW PARALLEL TO
THE FRONT...AND MORE EFFICIENT WARM RAIN PROCESSES. HRRR AND OTHER
HI-RES GUIDANCE HAVE HAD A VERY GOOD HANDLE ON CONVECTION SO FAR
TODAY AND SUGGEST THUNDERSTORMS WILL DISSIPATE AND DRIFT SOUTH BY
AROUND 03Z WITH THE LOSS OF DAYTIME HEATING AND GRADUAL SOUTHWARD
PUSH OF FRONT. DRY CONDITIONS THEN EXPECTED FOR THE REST OF THE
PERIOD AS HIGH AMPLITUDE RIDGE FOLDS INTO THE GREAT LAKES AND
SUPPORTS SURFACE HIGH PRESSURE. A STRAY SHOWER MAY BE POSSIBLE
TOMORROW MORNING IN OUR FAR SOUTHERN COUNTIES BUT CHANCES ARE VERY
LOW. THERMAL PROFILES BEHIND THIS FRONT ARE NOT VERY DIFFERENT FROM
CURRENT VALUES AND EXPECT INCREASING SUN TO SUPPORT ANOTHER DAY OF
HIGHS NEAR 80F. DEWPOINTS WILL BE TOUCH LOWER THOUGH...TAKING THE
HUMIDITY DOWN A NOTCH.
&&
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 336 PM EDT WED MAY 28 2014
LONG WAVE PATTERN WITH HIGHLY AMPLIFIED RIDGE OVER THE CENTRAL US
WILL START THE LONG TERM PERIOD. TROF ALONG THE NOAM WEST COAST
EJECTS EASTWARD AND WHILE MODELS DIFFER ON THE TIMING AND
EVOLUTION THERE IS ENOUGH CONSENSUS TO SUPPORT A FLATTENING OF THE
RIDGE OVER THE GREAT LAKES REGION TOWARD THE END OF THE LONG TERM
PERIOD.
THE CHALLENGE IS THE SIGNIFICANT DIFFERENCE BETWEEN THE 06Z AND 12Z
GFS RUN. 12Z MODEL IS MORE CLOSELY ALIGNED WITH THE GEM/ECMWF AND
UKMET - THE 06Z AS THE OUTLIER HAD THE LOW EJECTING FROM THE PLAINS
IN WHAT APPEARS TO BE MUCH TO FAST AND TOO FAR SOUTH.
REGARDLESS WITH ABUNDANT LOW LEVEL MOISTURE AND THE AREA WITHIN THE
WARM SECTOR...EXPECT TO SEE CONVECTION DEVELOP AS CURRENTLY FORECAST
AND SHOULD NOT CAUSE A DRAMATIC CHANGE TO CURRENT GRIDDED FORECAST.
AS THE RIDGE FLATTENS AND WESTERLY FLOW INCREASES WOULD EXPECT TO
SEE THE FRONTAL BOUNDARY PUSH SOUTH OF THE AREA DURING THE LATTER
PART OF THE EXTENDED PERIOD...WITH SLIGHT COOLING. TEMPERATURES
SHOULD STILL REMAIN ABOVE NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 147 PM EDT WED MAY 28 2014
WEAK COLD FRONT IS CURRENTLY DRAPED ACROSS THE AREA AND STRONG
DIABATIC HEATING HAS ALLOWED SCT SHOWERS AND THUNDERSTORMS TO
DEVELOP ALONG AND AHEAD OF IT. THE FRONT IS CURRENTLY SOUTH OF
KSBN BUT THESE STORMS MAY IMPACT KFWA THROUGH THE AFTERNOON.
LIMITED SHEAR AND LACK OF FOCUSED TRIGGERING MECHANISM WILL KEEP
CONVECTION SCATTERED AND DISORGANIZED THROUGH THE AFTERNOON BUT
BRIEF HEAVY RAIN AND STRONG WINDS WILL BE POSSIBLE. THUNDERSTORMS
EXPECTED TO DISSIPATE QUICKLY AFTER SUNSET AND DRY CONDITIONS
EXPECTED FOR THE REST OF THE PERIOD. SOME CONCERN FOR MVFR
CEILINGS AND/OR VISIBILITIES EARLY TOMORROW MORNING BUT CONFIDENCE
IS TOO LOW FOR INCLUSION IN THE TAF AT THIS TIME.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...CEO
SHORT TERM...AGD
LONG TERM...LEWIS
AVIATION...AGD
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
336 PM EDT WED MAY 28 2014
.SYNOPSIS...
ISSUED AT 451 AM EDT WED MAY 28 2014
A FRONTAL BOUNDARY WILL DROP SOUTHWARD INTO THE AREA TODAY
BRINGING MORE SCATTERED SHOWERS AND THUNDERSTORMS. THIS FRONT WILL
TRACK SOUTH OF THE AREA TONIGHT BRINGING AN END TO THE RAIN
CHANCES. HIGH TEMPERATURES THIS AFTERNOON WILL RANGE FROM THE
LOWER TO MID 80S ACROSS CENTRAL INDIANA TO THE LOWER 70S ACROSS
EASTERN LOWER MICHIGAN. LOW TEMPERATURES TONIGHT WILL RANGE FROM
50 TO 55 ACROSS MUCH OF CENTRAL AND SOUTHERN LOWER MICHIGAN...TO
THE UPPER 50S AND LOWER 60S ELSEWHERE.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 336 PM EDT WED MAY 28 2014
LOOSELY DEFINED "COLD" FRONT...MORE ACCURATELY DESCRIBED AS A WEAK
SURFACE PRESSURE TROUGH WITH A MODEST MOISTURE/DENSITY
GRADIENT...CONTINUES TO SLOWLY PUSH SOUTH ACROSS THE AREA AT PRESS
TIME. AS PREVIOUSLY NOTED...VERY LITTLE SYNOPTIC SUPPORT ALONG THIS
FRONT WITH JUST A VERY WEAK VORTICITY LOBE WINDING DOWN ACROSS THE
REGION. SHOWERS AND THUNDERSTORMS BEING DRIVEN BY SUBTLE CONVERGENCE
ALONG OLD OUTFLOW/DIFFERENTIAL HEATING BOUNDARIES IN A MOIST AND
MARGINALLY UNSTABLE AIRMASS. EARLY DAY INSOLATION ALLOWED FOR A
DECENT RISE IN MLCAPE VALUES ACROSS OUR SOUTHERN COUNTIES WHILE FAR
NORTHERN ZONES REMAIN LARGELY CAPPED AND STABLE. NUMEROUS SHOWERS
AND THUNDERSTORMS HAVE THEREFORE DEVELOPED IN OUR SOUTHERN CWA AS
EXPECTED. LACK OF APPRECIABLE SHEAR AND/OR CLEAR FORCING MECHANISM
WILL CONTINUE TO SUPPORT PULSE/MULTICELLULAR MODE THROUGH THE
EVENING. AN ISOLATED WET MICROBURST MAY BE POSSIBLE ONCE AGAIN BUT
THREAT FOR MORE WIDESPREAD SEVERE WEATHER IS VERY LOW. HEAVY RAIN IS
STILL THE MAIN THREAT WITH HIGH PW VALUES...WEAK FLOW PARALLEL TO
THE FRONT...AND MORE EFFICIENT WARM RAIN PROCESSES. HRRR AND OTHER
HI-RES GUIDANCE HAVE HAD A VERY GOOD HANDLE ON CONVECTION SO FAR
TODAY AND SUGGEST THUNDERSTORMS WILL DISSIPATE AND DRIFT SOUTH BY
AROUND 03Z WITH THE LOSS OF DAYTIME HEATING AND GRADUAL SOUTHWARD
PUSH OF FRONT. DRY CONDITIONS THEN EXPECTED FOR THE REST OF THE
PERIOD AS HIGH AMPLITUDE RIDGE FOLDS INTO THE GREAT LAKES AND
SUPPORTS SURFACE HIGH PRESSURE. A STRAY SHOWER MAY BE POSSIBLE
TOMORROW MORNING IN OUR FAR SOUTHERN COUNTIES BUT CHANCES ARE VERY
LOW. THERMAL PROFILES BEHIND THIS FRONT ARE NOT VERY DIFFERENT FROM
CURRENT VALUES AND EXPECT INCREASING SUN TO SUPPORT ANOTHER DAY OF
HIGHS NEAR 80F. DEWPOINTS WILL BE TOUCH LOWER THOUGH...TAKING THE
HUMIDITY DOWN A NOTCH.
&&
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 336 PM EDT WED MAY 28 2014
LONG WAVE PATTERN WITH HIGHLY AMPLIFIED RIDGE OVER THE CENTRAL US
WILL START THE LONG TERM PERIOD. TROF ALONG THE NOAM WEST COAST
EJECTS EASTWARD AND WHILE MODELS DIFFER ON THE TIMING AND
EVOLUTION THERE IS ENOUGH CONSENSUS TO SUPPORT A FLATTENING OF THE
RIDGE OVER THE GREAT LAKES REGION TOWARD THE END OF THE LONG TERM
PERIOD.
THE CHALLENGE IS THE SIGNIFICANT DIFFERENCE BETWEEN THE 06Z AND 12Z
GFS RUN. 12Z MODEL IS MORE CLOSELY ALIGNED WITH THE GEM/ECMWF AND
UKMET - THE 06Z AS THE OUTLIER HAD THE LOW EJECTING FROM THE PLAINS
IN WHAT APPEARS TO BE MUCH TO FAST AND TOO FAR SOUTH.
REGARDLESS WITH ABUNDANT LOW LEVEL MOISTURE AND THE AREA WITHIN THE
WARM SECTOR...EXPECT TO SEE CONVECTION DEVELOP AS CURRENTLY FORECAST
AND SHOULD NOT CAUSE A DRAMATIC CHANGE TO CURRENT GRIDDED FORECAST.
AS THE RIDGE FLATTENS AND WESTERLY FLOW INCREASES WOULD EXPECT TO
SEE THE FRONTAL BOUNDARY PUSH SOUTH OF THE AREA DURING THE LATTER
PART OF THE EXTENDED PERIOD...WITH SLIGHT COOLING. TEMPERATURES
SHOULD STILL REMAIN ABOVE NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 147 PM EDT WED MAY 28 2014
WEAK COLD FRONT IS CURRENTLY DRAPED ACROSS THE AREA AND STRONG
DIABATIC HEATING HAS ALLOWED SCT SHOWERS AND THUNDERSTORMS TO
DEVELOP ALONG AND AHEAD OF IT. THE FRONT IS CURRENTLY SOUTH OF
KSBN BUT THESE STORMS MAY IMPACT KFWA THROUGH THE AFTERNOON.
LIMITED SHEAR AND LACK OF FOCUSED TRIGGERING MECHANISM WILL KEEP
CONVECTION SCATTERED AND DISORGANIZED THROUGH THE AFTERNOON BUT
BRIEF HEAVY RAIN AND STRONG WINDS WILL BE POSSIBLE. THUNDERSTORMS
EXPECTED TO DISSIPATE QUICKLY AFTER SUNSET AND DRY CONDITIONS
EXPECTED FOR THE REST OF THE PERIOD. SOME CONCERN FOR MVFR
CEILINGS AND/OR VISIBILITIES EARLY TOMORROW MORNING BUT CONFIDENCE
IS TOO LOW FOR INCLUSION IN THE TAF AT THIS TIME.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MARSILI
SHORT TERM...AGD
LONG TERM...LEWIS
AVIATION...AGD
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
311 PM CDT WED MAY 28 2014
.SYNOPSIS...
ISSUED AT 310 PM CDT WED MAY 28 2014
12Z UA ANALYSIS HAS A WEAK UPPER LOW IN NORTHEAST IOWA WITH A
STRONGER UPPER LOW IN SOUTHWEST ARKANSAS. SEVERAL WEAK DISTURBANCES
WERE ROTATING AROUND THE LOWS. SATELLITE/RADAR TRENDS THROUGH MID
AFTERNOON SHOW DIURNAL CONVECTION ACROSS EASTERN IOWA AND NORTHERN
ILLINOIS THAT WAS SLOWLY ROTATING AROUND THE UPPER LOW IN EASTERN
IOWA.
18Z SFC ANALYSIS HAS AS WEAK LOW NEAR KAWG WITH A BOUNDARY EASTWARD
THROUGH CENTRAL ILLINOIS. DEW POINTS WERE IN THE 60S FROM THE GULF
COAST INTO THE MID MISSISSIPPI AND OHIO VALLEYS. DEW POINTS IN THE
40S AND 50S WERE ACROSS THE GREAT LAKES.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 310 PM CDT WED MAY 28 2014
RECENT RAP TRENDS INDICATE THE EFFECTIVE BOUNDARY WILL REMAIN NEARLY
STATIONARY FROM ABOUT KAWG TO NEAR KPNT THROUGH LATE AFTERNOON. WITH
THE WEAK UPPER LOW JUST WEST OF THE QUAD CITIES...CONVECTION WILL
DRIFT SLOWLY SOUTH WEST OF THE MISSISSIPPI AND SLOWLY NORTH EAST OF
THE MISSISSIPPI.
DUE TO THE SLOW MOVEMENT OF STORMS...LOCALLY HEAVY RAINFALL WILL BE
SEEN.
BY EARLY EVENING AND CONTINUING THROUGH SUNSET CONVECTION WILL
SLOWLY DISSIPATE WITH CONVECTION BECOMING VERY ISOLATED BY MIDNIGHT.
DURING THE EVENING THE BOUNDARY WILL SLOWLY DRIFT SOUTH AND WILL BE
THE FOCUS FOR MAINTAINING ISOLATED CONVECTION PAST SUNSET.
AFTER MIDNIGHT MOST OF THE AREA IS EXPECTED TO REMAIN DRY AS THE
BOUNDARY CONTINUES A SLOW DRIFT TO THE SOUTH. ANY REMAINING RAIN
WILL BE CONFINED TO AREAS CLOSE TO THE FRONT.
THURSDAY MORNING THERE MAY BE SOME LINGERING SHOWERS ACROSS THE FAR
SOUTH CLOSE TO THE BOUNDARY WHILE THE REMAINDER OF THE AREA IS DRY.
NEW DIURNAL CONVECTION IS EXPECTED TO DEVELOP BY LATE MORNING AND
CONTINUE THROUGH THURSDAY AFTERNOON SOUTH OF I-80. THIS NEW
CONVECTION IS EXPECTED TO BE ISOLATED IN NATURE BUT MAY BE MORE
SCATTERED BETWEEN KBRL AND KUIN.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 310 PM CDT WED MAY 28 2014
SURFACE AND UPPER RIDGING WILL MOVE THROUGH THE REGION LATE THIS
WEEK KEEPING DRY WEATHER OVER THE AREA. THUNDERSTORM CHANCES WILL
RETURN TO THE FORECAST OVER THE WEEKEND AND EARLY NEXT WEEK AS LOW
LEVEL MOISTURE INCREASES BEHIND THE DEPARTING RIDGE. THE BEST CHANCE
OF THUNDERSTORMS WILL BE TUESDAY INTO WEDNESDAY AS A COLD FRONT MOVES
SLOWLY THROUGH THE REGION.
THURSDAY NIGHT INTO FRIDAY NIGHT LESS HUMID CONDITIONS WILL BE IN PLACE
WITH A SURFACE HIGH OVER THE WESTERN GREAT LAKES FEEDING DRY AIR
INTO THE REGION. TEMPERATURES SHOULD BE SEASONAL WITH HIGHS FRIDAY
IN THE LOW 80S AND LOWS THURSDAY AND FRIDAY MORNINGS IN THE MID 50S
TO MID 60S.
THUNDERSTORM CHANCES CREEP BACK INTO THE FORECAST FOR THE WEEKEND AS
THE UPPER AND SURFACE RIDING MOVE EAST ALLOWING MOIST RETURN FLOW
TO SET UP. FOR NOW WITHOUT ANY OBVIOUS FORCING MECHANISMS SHOWN IN
THE MODEL SOLUTIONS KEPT POPS IN THE LOW CHANCE CATEGORY.
MODEL SOLUTIONS SHOW A BETTER THREAT OF THUNDERSTORMS EARLY NEXT
WEEK WITH A PERSISTENT SOUTHWEST TROF IN PLACE AND A SERIES OF S/WS
EJECTING OUT OF THE TROF INTO THE PLAINS AND UPPER MIDWEST. THIS
WILL SEND A SLOW MOVING COLD FRONT THROUGH THE REGION TUESDAY INTO
WEDNESDAY. THE GFS/ECMWF GENERALLY AGREE ON THE OVER ALL SYNOPTIC
PATTERN EARLY NEXT WEEK BUT HAVE DIFFERENT TAKES ON HANDLING THE
S/WS IN THE SOUTHWEST FLOW AND THE SURFACE FRONT. THE GFS BRINGS
OUT A MAIN S/W MONDAY NIGHT AND TUESDAY WHICH PUSHES THE COLD FRONT
SOUTHEAST OF THE FORECAST AREA BY WEDNESDAY. THE ECMWF IS MORE
FRAGMENTED WITH THE S/WS AND STALLS THE FRONT OVER OR JUST SOUTH OF
THE CWA BY LATE TUESDAY. EITHER SOLUTION THOUGH SUPPORTS AN ACTIVE
PATTERN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1222 PM CDT WED MAY 28 2014
A WEAK BOUNDARY ACROSS NORTHERN ILLINOIS INTO EASTERN IOWA
COMBINED WITH A DISTURBANCE ALOFT WAS HELPING TO INITIATE
CONVECTION. VFR CONDITIONS ARE EXPECTED EXCEPT FOR MVFR/IFR
CONDITIONS AROUND CONVECTION THROUGH 03Z/29. THE SLOW MOVEMENT OF
THE CONVECTION MEANS THAT SHRA/TSRA MAY PERSIST AT A TAF SITE. AFT
06Z/29 MVFR CONDITIONS ARE EXPECTED TO DEVELOP THROUGH SUNRISE
THURSDAY.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...08
SHORT TERM...08
LONG TERM...DLF
AVIATION...08
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1117 PM CDT TUE MAY 27 2014
.UPDATE...
ISSUED AT 914 PM CDT TUE MAY 27 2014
SIGNIFICANTLY CUT BACK ON POP FOR THE OVERNIGHT. SHOWERS AND ISO
STORMS HAVE ENDED WITH LACK OF HEATING. A FEW LINGERING AND
DIMINISHING SHOWERS EXPECTED TO END SOON. COMPLEX OF STORMS OVER
SD AND WESTERN MN TO GRADUALLY WEAKEN NEXT FEW HOURS. HRRR SHOWED
A LINGERING SHOWER FAR NW IA THROUGH EARLY MORNING. WILL MONITOR
TO SEE IF COLD POOL CAN HOLD THEM TOGETHER LONGER. /REV
&&
.SHORT TERM /TONIGHT/...
ISSUED AT 324 PM CDT TUE MAY 27 2014
PRIMARY CONCERN REMAINS PRECIP TRENDS INTO THE NIGHT. PARENT WAVE
OF MEANDERING UPPER LEVEL LONG WAVE TROUGH CONTINUES TO DRIFT ALONG
THE RED RIVER WHILE SEPARATE WEAKER WAVE INFLUENCES OUR WEATHER
ALONG THE UPPER MS VALLEY. TWO CURRENT CLUSTERS OF CONVECTION ARE
SUBTLELY FORCED BUT APPEAR TO BE MAINLY DRIVEN BY FORCING
ATTENDANT TO THE AFOREMENTIONED SHORT WAVE AND WEAK CONVERGENCE
ALONG DIFFICULT TO ANALYZE SW-NE WEAK FRONT/PRESSURE TROUGH.
AIRMASS IS RATHER HOMOGENEOUS WITH ONLY WEAK DRYING BEHIND WIND
SHIFT.
SHORT WAVE SHOULD DRIFT DOWN THE IMMEDIATE UPPER MS RIVER VALLEY
TONIGHT KEEPING CLOUDS IN THE FORECAST AND SOME POPS...ESPECIALLY
EAST...WHICH SHOULD VERY GRADUALLY DIMINISH INTO THE NIGHT WITH LOSS
OF INSOLATION. FARTHER SOUTH HI RES CONVECTION ALLOWING
MODELS...ESPECIALLY THE HOPWRF ENSEMBLE WHICH HAS PERFORMED WELL
RECENTLY...SUGGESTS THIS CLUSTER SHOULD DIMINISH AND/OR EXIT THE SRN
FORECAST AREA THIS EVENING.
FREEZING LEVELS HAVE LOWERED SOMEWHAT TODAY VS YESTERDAY SO
THERMODYNAMIC ENVIRONMENT FOR HEAVY RAIN IS SLIGHTLY LESS FAVORABLE
THIS AFTERNOON. HOWEVER ENVIRONMENT IMPROVES SOMEWHAT LATER THIS
EVENING AS WARM CLOUD DEPTHS INCREASE WITH LOWERING LCLS...AND PWS
BEGIN TO POOL IN THE VICINITY OF THE BOUNDARY. THE WINDOW FOR THIS
TO BE REALIZED WILL BE SMALL HOWEVER WITH COINCIDENT LOSS OF
HEATING.
FUNNEL CLOUD ENVIRONMENT IS STILL SOMEWHAT ELEVATED INTO PEAK
HEATING MAX WITH 0-3KM CAPES 150 J/KG OR MORE AND NON SUPERCELL
TORNADO PARAMETER 2-3 SOUTH. WEAK SURFACE VORTICITY HAS LIKELY
PRECLUDED ANY REPORTS AS OF YET BUT WILL HAVE TO MONITOR LOCAL
OUTFLOW BOUNDARIES...WHICH MAY BE PREVALENT IN THIS LOW 0-6KM SHEAR
SITUATION...FOR ISOLATED VORTICITY GENERATION IN NEW CELL
DEVELOPMENT.
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
ISSUED AT 324 PM CDT TUE MAY 27 2014
WEAK UPPER LEVEL SHORTWAVE EMBEDDED IN THE MAIN UPPER LEVEL FLOW TO
SLOWLY DEEPEN A BIT AS IT DROPS SOUTHEASTWARD/SOUTHWARD THROUGH THE
CWA WEDNESDAY INTO WEDNESDAY NIGHT. THIS WILL BRING A WEAK BACKDOOR
COOL FRONT ALONG WITH IT...WITH SOME WEAK INSTABILITY IN PLACE
ACROSS THE CWA RESULTING IN CHANCES FOR ISOLATED TO SCATTERED
SHOWER/THUNDERSTORM DEVELOPMENT THROUGH THE DAY WEDNESDAY INTO
WEDNESDAY NIGHT. THE UPPER RIDGING IN PLACE ACROSS THE CENTRAL
US...WILL AMPLIFY LATE THIS WEEK...WITH THE AREA OF HIGH PRESSURE
ACROSS THE HIGH PLAINS SLIDING NORTHEAST WITH RETURN FLOW SETTING UP
ACROSS THE AREA BY THURSDAY INTO FRIDAY. THIS WILL ALLOW GULF
MOISTURE TO STREAM BACK NORTHWARD BY LATE WEEK INTO THE
WEEKEND...WITH THETA-E RIDGING BUILDING NORTHWARD THROUGH THE
WESTERN/CENTRAL CWA. THEREFORE CHANCES FOR CONVECTION CREEP BACK
INTO THE CWA. FROM WEST TO EAST BY LATE THIS WEEK. THE ACTIVE
PATTERN CONTINUES INTO THE WEEKEND/EARLY NEXT WEEK AS AN UPPER
TROUGH DIGS INTO THE WESTERN US...SETTING UP SOUTHWESTERLY UPPER
LEVEL FLOW ACROSS THE CENTRAL US AND STRONGER FLOW OFF THE GULF.
GFS/EC HAVE A SFC LOW EJECTING NORTHEASTWARD ACROSS THE CENTRAL
PLAINS INTO THE ERN DAKOTAS/WRN MN AREA BY LATE MONDAY INTO TUESDAY.
THIS SHOULD PUT THE DMX CWA IN THE WARM SECTOR WITH INCREASING
CHANCES FOR CONVECTION SUNDAY INTO MONDAY AS THE ASSOCIATED WARM
FRONT LIFTS THROUGH THE CWA AND A DRY LINE FEATURE SURGES THROUGH AS
WELL. THIS SCENARIO WOULD LIKELY BRING A SEVERE WEATHER THREAT BACK
TO THE CWA AS WELL AS INCREASING CHANCES FOR THUNDERSTORMS AND
WIDESPREAD RAINFALL.
AS FOR TEMPERATURES...H85 TEMPS IN THE MID TEENS THROUGHOUT MUCH OF
THE WEEK AND INCREASE TOWARD THE UPPER TEENS BY THE WEEKEND INTO
EARLY NEXT WEEK. THEREFORE EXPECT THE TREND OF NEAR AVERAGE TO
SLIGHTLY ABOVE AVERAGE TEMPERATURES TO CONTINUE THROUGH THE MID/LONG
RANGE.
&&
.AVIATION...28/06Z
ISSUED AT 1117 PM CDT TUE MAY 27 2014
MAIN CONCERN OVERNIGHT WILL BE POTENTIAL FOR IFR CIGS NORTH AND
NORTHEAST AS ST DECK FROM SOUTHEAST MN MOVES SOUTH. SHOWERS AND
STORMS HAVE ENDED FOR NOW...BUT WITH UPPER LOW OVER EASTERN IOWA
WED... WILL SEE DAYTIME INSTABILITY INCREASE AND AFT 15Z...SHOWERS
AND SCT THUNDER INCREASING EAST HALF. HAVE MENTION OF VCTS AGAIN
EAST DUE TO SCT NATURE OF EXPECTED COVERAGE. SOME LIGHT FOG NEAR
AM WILL END AFT 14Z. WINDS REMAIN GENERALLY LIGHT WITH CLOUDS
REMAINING MVFR TO VFR BALANCE OF FORECAST./REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...REV
SHORT TERM...SMALL
LONG TERM...BEERENDS
AVIATION...REV
AREA FORECAST DISCUSSION
NWS GOODLAND KS
228 AM MDT WED MAY 28 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 1244 PM MDT TUE MAY 27 2014
MOSTLY SUNNY SKIES...WITH A CUMULUS FIELD DEVELOPING...EXIST OVER
THE CWA THIS AFTERNOON. AN UPPER LOW IS CURRENTLY CIRCULATING OVER
THE SOUTH CENTRAL PLAINS WITH UPPER LEVEL RIDGING MOVING INTO THE
HIGH PLAINS. ENERGY FROM A SHORTWAVE TROUGH OVER THE MIDWEST IS
ROTATING THROUGH EASTERN NEBRASKA. THE REMAINDER OF THE AFTERNOON
SHOULD REMAIN DRY...EVEN THOUGH THE HRRR AND THE PREVIOUS NAM
DEVELOPED SHOWERS OVER RED WILLOW COUNTY NEBRASKA AND NORTON
COUNTY KANSAS LATER THIS AFTERNOON. SINCE THE SHORTWAVE ENERGY
APPEARS TO NOT STRETCH THIS FAR WEST...AND CONSIDERING THE HRRR
HAS NOT BEEN CONSISTENT FROM RUN TO RUN AND THE 12Z NAM REMOVED
PRECIP FROM THE CWA...DECIDED TO GO WITH A DRY FORECAST FOR THIS
AFTERNOON. WINDS WILL BE OUT OF THE EAST NORTHEAST...SHIFTING TO
THE SOUTHEAST OVERNIGHT TO THE SOUTHWEST BY MORNING...AND WILL
REMAIN LIGHT. SCATTERED TO BROKEN CUMULUS THAT DEVELOPS THIS
AFTERNOON WILL DECREASE AFTER SUNSET AS INSTABILITY
DIMINISHES...LEAVING MOSTLY CLEAR SKIES TONIGHT INTO TOMORROW
MORNING.
MOSTLY DRY AND WARM CONDITIONS WILL PERSIST OVER THE CWA TOMORROW.
INCREASED TEMPERATURES SLIGHTLY INTO THE UPPER 80S TO LOW 90S AS
THE RIDGE MOVES OVERHEAD AND 850MB TEMPS RISE INTO THE 20C TO 25C
RANGE. BY AFTERNOON...WINDS WILL SHIFT TO THE EAST SOUTHEAST AT
10 TO 15 MPH...WHICH WILL PROVIDE UPSLOPE FLOW. UPSLOPE FLOW
COMBINED WITH TEMPERATURES HEATING UP COULD PRODUCE THUNDERSTORMS
ALONG THE HIGHER TERRAIN IN COLORADO THAT COULD MOVE EAST INTO FAR
EASTERN COLORADO. SOME OF THE MODELS WERE PICKING UP ON THIS...SO
WENT WITH A SLIGHT CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS
TOMORROW AFTERNOON...AROUND 21Z TO 23Z...FOR PORTIONS OF EASTERN
COLORADO. CAPE IS UNDER 1000 J/KG...SO THUNDERSTORMS THAT DEVELOP
WILL BE ISOLATED AND MAY NOT HAVE ENOUGH STRENGTH TO MAKE IT INTO
THE CWA BUT KEPT IT AT SLIGHT CHANCE FOR ANY THAT MAY MAKE INTO
THE CWA. MOST LOCATIONS SHOULD REMAIN DRY TOMORROW WITH A FEW
CLOUDS AND MOSTLY SUNNY SKIES.
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 225 AM MDT WED MAY 28 2014
THE UPPER LEVEL RIDGE WILL MOVE EASTWARD SATURDAY AS AN UPPER LEVEL
TROUGH BEGINS TO MOVE INTO THE WESTERN CONUS. THE APPROACH OF THE
UPPER LEVEL TROUGH WILL BRING A STORMY WEATHER PATTERN TO THE TRI
STATE AREA WITH CHANCES FOR WIDESPREAD SHOWERS AND THUNDERSTORMS.
LATEST MODEL GUIDANCE SHOWS DISAGREEMENT WITH POSITION OF STRONGEST
MID AND LOWER LEVEL JET...SO STRENGTH OF STORMS OVER THE IMMEDIATE
FORECAST AREA IS IN QUESTION. JET LIFT WILL CONTINUE TO BRING
CHANCES FOR THUNDERSTORM DEVELOPMENT ACROSS THE HIGH PLAINS INTO
MONDAY. A SHORTWAVE RIDGE WILL BUILD IN BETWEEN UPPER LEVEL SYSTEMS
ON TUESDAY...WHICH WILL BRING DRIER CONDITIONS WITH REDUCED CHANCES
FOR STORM DEVELOPMENT. TEMPERATURES FOR SATURDAY THROUGH MONDAY WILL
BE IN THE UPPER 80S...WHICH IS ABOVE AVERAGE FOR THIS TIME OF
YEAR. A SURFACE COLD FRONT WILL SLIDE INTO THE HIGH PLAINS MONDAY
EVENING...WHICH WILL LOWER TEMPERATURES TO NEAR NORMAL IN THE LOW TO
MID 80S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1100 PM MDT TUE MAY 27 2014
KGLD AND KMCK...VFR CONDITIONS THROUGH THE PERIOD. LIGHT/VARIABLE
WINDS UNDER 8KTS EXPECTED AT BOTH TERMINALS THROUGH 16Z THEN
BECOMING SOUTHEASTERLY AROUND 10KTS FROM 17Z THROUGH THE REST OF
THE TAF.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...ALW
LONG TERM...MK
AVIATION...99
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1115 PM MDT TUE MAY 27 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 1244 PM MDT TUE MAY 27 2014
MOSTLY SUNNY SKIES...WITH A CUMULUS FIELD DEVELOPING...EXIST OVER
THE CWA THIS AFTERNOON. AN UPPER LOW IS CURRENTLY CIRCULATING OVER
THE SOUTH CENTRAL PLAINS WITH UPPER LEVEL RIDGING MOVING INTO THE
HIGH PLAINS. ENERGY FROM A SHORTWAVE TROUGH OVER THE MIDWEST IS
ROTATING THROUGH EASTERN NEBRASKA. THE REMAINDER OF THE AFTERNOON
SHOULD REMAIN DRY...EVEN THOUGH THE HRRR AND THE PREVIOUS NAM
DEVELOPED SHOWERS OVER RED WILLOW COUNTY NEBRASKA AND NORTON
COUNTY KANSAS LATER THIS AFTERNOON. SINCE THE SHORTWAVE ENERGY
APPEARS TO NOT STRETCH THIS FAR WEST...AND CONSIDERING THE HRRR
HAS NOT BEEN CONSISTENT FROM RUN TO RUN AND THE 12Z NAM REMOVED
PRECIP FROM THE CWA...DECIDED TO GO WITH A DRY FORECAST FOR THIS
AFTERNOON. WINDS WILL BE OUT OF THE EAST NORTHEAST...SHIFTING TO
THE SOUTHEAST OVERNIGHT TO THE SOUTHWEST BY MORNING...AND WILL
REMAIN LIGHT. SCATTERED TO BROKEN CUMULUS THAT DEVELOPS THIS
AFTERNOON WILL DECREASE AFTER SUNSET AS INSTABILITY
DIMINISHES...LEAVING MOSTLY CLEAR SKIES TONIGHT INTO TOMORROW
MORNING.
MOSTLY DRY AND WARM CONDITIONS WILL PERSIST OVER THE CWA TOMORROW.
INCREASED TEMPERATURES SLIGHTLY INTO THE UPPER 80S TO LOW 90S AS
THE RIDGE MOVES OVERHEAD AND 850MB TEMPS RISE INTO THE 20C TO 25C
RANGE. BY AFTERNOON...WINDS WILL SHIFT TO THE EAST SOUTHEAST AT
10 TO 15 MPH...WHICH WILL PROVIDE UPSLOPE FLOW. UPSLOPE FLOW
COMBINED WITH TEMPERATURES HEATING UP COULD PRODUCE THUNDERSTORMS
ALONG THE HIGHER TERRAIN IN COLORADO THAT COULD MOVE EAST INTO FAR
EASTERN COLORADO. SOME OF THE MODELS WERE PICKING UP ON THIS...SO
WENT WITH A SLIGHT CHANCE OF SHOWERS AND ISOLATED THUNDERSTORMS
TOMORROW AFTERNOON...AROUND 21Z TO 23Z...FOR PORTIONS OF EASTERN
COLORADO. CAPE IS UNDER 100O J/KG...SO THUNDERSTORMS THAT DEVELOP
WILL BE ISOLATED AND MAY NOT HAVE ENOUGH STRENGTH TO MAKE IT INTO
THE CWA BUT KEPT IT AT SLIGHT CHANCE FOR ANY THAT MAY MAKE INTO
THE CWA. MOST LOCATIONS SHOULD REMAIN DRY TOMORROW WITH A FEW
CLOUDS AND MOSTLY SUNNY SKIES.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 152 PM MDT TUE MAY 27 2014
UPPER RIDGING WILL RESULT IN DRY AND WARM CONDITIONS THROUGH
THURSDAY. UPSLOPE FLOW INTO THE HIGHER TERRAIN THURSDAY AFTERNOON
WILL INITIATE CONVECTION NEAR THE FRONT RANGE...WHICH MIGHT MAKE
IT INTO NORTHEAST COLORADO BEFORE DISSIPATING THURSDAY EVENING.
THAT PATTERN REPEATS ON FRIDAY...BUT WITH THE UPPER RIDGE MOVING
FURTHER EAST THERE IS A BETTER CHANCE THAT THE COLORADO CONVECTION
WILL MAKE IT INTO THE WESTERN HALF OF THE LOCAL FORECAST AREA
FRIDAY EVENING. ON SATURDAY...WEAK SHORTWAVE EMBEDDED IN THE
SOUTHWEST FLOW AND LEE TROUGH AT THE SURFACE WILL COMBINE TO
INITIATE CONVECTION FURTHER EAST WITH SCATTERED STORMS THROUGH
SATURDAY NIGHT. BEST CHANCES FOR THUNDERSTORMS IN THE PERIOD
APPEAR TO BE ON SUNDAY WITH STRONGER AND BETTER DEFINED UPPER
SHORTWAVE. SLIGHT TO LOW CHANCES FOR THUNDERSTORMS WILL CONTINUE
EARLY NEXT WEEK...BUT MAIN FORCING WILL BE NORTH OF THE AREA AND
PATTERN SUGGESTS A RATHER ROBUST DRY SLOT FURTHER SOUTH WHICH MAY
INHIBIT CHANCES HERE. TEMPERATURES WILL BE SLIGHTLY ABOVE NORMAL
THROUGH THE ENTIRE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1100 PM MDT TUE MAY 27 2014
KGLD AND KMCK...VFR CONDITIONS THROUGH THE PERIOD. LIGHT/VARIABLE
WINDS UNDER 8KTS EXPECTED AT BOTH TERMINALS THROUGH 16Z THEN
BECOMING SOUTHEASTERLY AROUND 10KTS FROM 17Z THROUGH THE REST OF
THE TAF.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...ALW
LONG TERM...024
AVIATION...99
AREA FORECAST DISCUSSION
NWS JACKSON KY
207 PM EDT WED MAY 28 2014
.UPDATE...
ISSUED AT 100 PM EDT WED MAY 28 2014
QUICK UPDATE TO FORECAST PACKAGE TO TWEAK GRIDS TO HOURLY OBS.
SHOWERS AND THUNDERSTORMS HAVE BEGUN TO FIRE WITH WHAT COULD BECOME A
BAND OF MORE ACTIVE WEATHER ACROSS THE HEART OF THE CWA...AND
EVENTUALLY THE EAST. HRRR HAS A DECENT HANDLE ON VERY SHORT TERM
EVENTS THUS FAR BUT MAY HAVE INITIATED CONVECTION JUST A BIT TOO FAR
NORTH AND EAST BASED ON CURRENT RADAR TRENDS. MADE CORRESPONDING
MINOR ADJUSTMENTS TO POPS FOR THIS. INCREASED AFTERNOON HIGHS JUST A
TAD BASED ON CURRENT TEMPS...WHICH HAVE ALREADY CLIMBED TO WITHIN A
DEGREE OR SO OF ADVERTISED HIGHS. SOME JUICY AIR OUT THERE THIS
AFTERNOON BUT STORMS DO NOT SEEM TO HAVE QUITE THE SAME PUNCH AND
COVERAGE AS YESTERDAY ATTM. ALSO...MID LEVELS DO NOT HAVE AS MUCH DRY
AIR AS YESTERDAY. CONSEQUENTLY DO NOT EXPECT TO SEE AS MANY REPORTS
OF WIND DAMAGE AS YESTERDAY.
UPDATE ISSUED AT 1000 AM EDT WED MAY 28 2014
UPDATED THE FORECAST PACKAGE TO REMOVE FOG AND TO NUDGE HOURLY GRIDS
TOWARDS HOURLY OBS. NO NEW DEVELOPMENTS ATTM. FLASH FLOOD WATCH WILL
REMAIN IN EFFECT FOR THOSE AREAS THAT SAW MOST SIGNIFICANT RAINFALL
YESTERDAY AND THAT HAVE BEST POTENTIAL FOR RAIN TODAY. HRRR STILL
SHOWS CONVECTION FIRING BETWEEN 16-18Z.
UPDATE ISSUED AT 755 AM EDT WED MAY 28 2014
HOURLY GRIDS HAVE BEEN FRESHENED UP FOR THE NEXT FEW HOURS BASED ON
RECENT OBS AND TRENDS IN THE NEAR TERM MODELS. THE HOURLY TEMPS WERE
ADJUSTED UP A BIT THROUGH ABOUT 18Z SIMILAR TO WHAT OCCURRED ON TUE.
THE HRRR RUNS CONTINUE TO SHOW CONVECTION DEVELOPING ABOUT 17Z OR 18Z
WITH THE BEST COVERAGE OVER THE CENTRAL AND EASTERN CWA...OR
LOCATIONS WHERE THE FLASH FLOOD WATCH IS IN EFFECT.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 345 AM EDT WED MAY 28 2014
EARLY THIS MORNING...A WARM AND RATHER MOIST AIR MASS WAS IN PLACE
ACROSS THE REGION. AT MID LEVELS...RIDGING OVER THE SOUTHEASTERN
STATES WAS BEGINNING TO DEPART TO THE SOUTH AND EAST WHILE ANOTHER
RIDGE WAS IN PLACE FROM THE FOUR CORNERS REGION NORTH-EAST INTO PARTS
OF THE CENTRAL PLAINS. IN BETWEEN...OVER THE ARKLATEX REGION A SLOW
MOVING UPPER LOW WAS MEANDERING TOWARD THE LOWER MS VALLEY REGION
WHILE A BROAD TROUGH EXTENDED FROM THE GREAT LAKES INTO THE MID MS
VALLEY REGION. THE WESTERLIES WERE DISPLACED TO THE NORTH OF THE
CENTRAL CONUS...BUT DIPPED SOUTH EAST INTO THE NORTHEASTERN CONUS. AT
THE SFC...AN AREA OF LOW PRESSURE WAS MOVING ACROSS SOUTHEAST NY
STATE WITH A TRAILING SLOW MOVING COLD FRONT WEST INTO THE GREAT
LAKES REGION...BEFORE BECOMING STATIONARY TO A SFC WAVE OVER THE
MIDWEST REGION.
TODAY INTO THURSDAY...THE MID LEVEL TROUGHING WILL GRADUALLY MOVE
SOUTHEAST BUT THE AXIS OF THIS TROUGH SHOULD NOT CROSS THE AREA UNTIL
AROUND THE END OF THE PERIOD. AT THE SAME TIME THE UPPER LOW IS
EXPECTED TO WEAKEN AND MOVE TOWARD THE MS DELTA REGION. OVERALL...THIS
SCENARIO WILL LEAD TO WEAK STEERING FLOW AS CONVECTION TODAY OR
THURSDAY THAT DEVELOPS PRIMARILY AROUND PEAK HEATING IN THE WARM AND
INCREASINGLY MOIST AIR MASS AS THE FRONT NEARS. IF SUFFICIENT HEATING
AND OR MOISTENING OCCURS FOR CAPE TO REACH 2000 J/KG OR MORE THIS
AFTERNOON...A STORM OR TWO MIGHT BECOME MARGINALLY SEVERE AND LEAD TO
DAMAGING WINDS AS OCCURRED ON TUE. STORMS SHOULD ALSO PRODUCE
LOCALLY HEAVY RAIN.
CONVECTION SHOULD BECOME MOST WIDESPREAD AS THE MID LEVEL DISTURBANCE
WORKS ACROSS THE OH VALLEY AND TOWARD THE APPALACHIANS LATE TONIGHT
AND INTO THU AT THE SAME TIME THAT THE COLD FRONT SAGS INTO THE AREA.
FLASH FLOODING WILL BE A CONCERN LATER TODAY AND PERHAPS MORE SO ON
THURSDAY. STORM MOTIONS WILL BE SLOW BOTH DAYS AND PW SHOULD BE AT
ITS HIGHEST ON THURSDAY...NEARING 2 SD ABOVE NORMAL. TRAINING COULD
ALSO OCCUR BOTH DAYS...AGAIN THURSDAY MAY BE THE BIGGER CONCERN
THOUGH AS THE STORM MOTIONS WILL BE NEARLY PARALLEL TO THE SAGGING
COLD FRONT. SINCE PARTS OF THE EASTERN CWA FROM ROWAN AND MORGAN
COUNTIES SOUTHEAST TOWARD PIKE COUNTY ARE ALREADY PRIMED FROM HEAVY
RAIN ON TUESDAY AND FFG VALUES ARE AS LOW AS 1.5 TO 2 INCHES FOR 1
HOUR AND 2 TO 2.5 IN THREE HOURS IN THESE AREAS...WE HAVE OPTED TO
ISSUE A FLASH FLOOD WATCH FROM 2 PM THIS AFTERNOON WHEN CONVECTION
SHOULD REALLY GET GOING THROUGH LATE THU EVENING...AROUND 11
PM...WHEN DRIER AIR SHOULD BE ADVECTING IN FROM THE NORTH BEHIND THE
BOUNDARY AND END THE THREAT.
DIURNAL RANGES SHOULD BE SOMEWHAT LIMITED THROUGH THE PERIOD DUE TO
THE MOIST AIR MASS AND CLOUDS. PATCHY VALLEY FOG SHOULD DISSIPATE BY 9
AM OR SO TODAY...BUT SHOULD DEVELOP AGAIN TONIGHT ESPECIALLY IN
LOCATIONS THAT RECEIVE THE HEAVIER RAINFALL LATER TODAY OR THIS EVENING.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 318 AM EDT WED MAY 28 2014
THE MODELS WERE NOT IN THE BEST OF AGREEMENT THIS GO ROUND IN THE
EXTENDED. THE OVERALL WEATHER PATTERN IN THE MODELS APPEARS TO
FEATURE A LARGE RIDGE OF HIGH PRESSURE ALOFT...WITH MOIST UNSTABLE
AIR BENEATH IT THAT WOULD ACT TO TRIGGER SHOWER AND THUNDERSTORM
ACTIVITY FROM TIME TO TIME THROUGH THE END OF THE PERIOD. WITH A
GOOD DEAL OF UNCERTAINTY IN THE MODEL DATA...DECIDED TO LEAN TOWARD
THE LESS ACTIVE ECMWF MODEL SOLUTION WITH LOWER POPS THAN THE LATEST
MEXMOS GUIDANCE WAS INDICATING. THAT BEING SAID...THE FORECAST WILL
FEATURE PRECIPITATION CHANCES THURSDAY NIGHT THROUGH FRIDAY
AFTERNOON...WITH A BRIEF LULL IN ACTIVITY FRIDAY NIGHT THROUGH LATE
SATURDAY NIGHT AS A SURFACE RIDGE TEMPORARILY TAKES HOLD. ONCE THE
GULF OPENS UP ON SUNDAY...IT APPEARS THERE WILL BE ENOUGH MOISTURE
AND INSTABILITY AVAILABLE TO SPARK SHOWERS AND STORM EACH DAY
THROUGH THE END OF THE EXTENDED PERIOD...WITH THE AFTERNOON AND
EVENING PERIODS BEING THE MOST ACTIVE. THE PERIOD WILL FEEL QUITE
SUMMER LIKE...WITH DAYTIME HIGHS EACH DAY IN THE 80S AND OVERNIGHT
LOWS IN THE 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 207 PM EDT WED MAY 28 2014
CONVECTION HAS FIRED ACROSS THE AREA THIS AFTERNOON. THUS FAR
ACTIVITY HAS BEEN SCATTERED BUT EXPECT AN INCREASE IN COVERAGE OVER
THE NEXT FEW HOURS...ESPECIALLY ACROSS THE CENTRAL AND EASTERN
PORTIONS OF OUR FORECAST AREA. AT PRESENT NOT SEEING MUCH AROUND ANY
OF OUR TERMINAL LOCATIONS. THEREFORE WENT WITH A PREDOMINANT -SHRA
WITH VCTY THUNDER AND WILL AMEND AS TIMING OF THUNDERSTORMS...IF ANY
INTO EACH TERMINAL BECOMES MORE CLEAR. WINDS ARE GENERALLY LIGHT BUT
MAY BECOME GUSTY AROUND THE STRONGEST THUNDERSTORMS. HOWEVER...MID
LEVELS ARE NOT AS DRY SO NOT EXPECTING WINDS OF THE MAGNITUDE SEEN
WITH THUNDERSTORMS YESTERDAY AFTERNOON. ALTHOUGH COVERAGE SHOULD PEAK
AND DIMINISH BY AROUND 22Z...CONVECTION WILL TEND TO LINGER INTO THE
EVENING TIME FRAME. SHOWERS AND THUNDERSTORMS REFIRE AGAIN TOMORROW
MORNING WITH THE HELP OF A BACKDOOR COLD FRONTAL BOUNDARY THAT WILL
BE PUSHING THROUGH EASTERN KENTUCKY DURING THE DAY ON THURSDAY.
MVFR...TO POSSIBLY IFR FOG SHOULD DEVELOP AT LOZ AND SME AND OTHER
VALLEY LOCATIONS AFTER ABOUT 4Z. WINDS WILL GENERALLY REMAIN LIGHT
BUT BECOME NORTHEASTERLY BEHIND THE FRONTAL BOUNDARY LATE THURSDAY
AFTERNOON.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR KYZ044-050>052-
060-104-106>110-112-113-115-118>120.
&&
$$
UPDATE...RAY
SHORT TERM...JP
LONG TERM...AR
AVIATION...JP/RAY
AREA FORECAST DISCUSSION
NWS JACKSON KY
100 PM EDT WED MAY 28 2014
.UPDATE...
ISSUED AT 100 PM EDT WED MAY 28 2014
QUICK UPDATE TO FORECAST PACKAGE TO TWEAK GRIDS TO HOURLY OBS.
SHOWERS AND THUNDERSTORMS HAVE BEGUN TO FIRE WITH WHAT COULD BECOME A
BAND OF MORE ACTIVE WEATHER ACROSS THE HEART OF THE CWA...AND
EVENTUALLY THE EAST. HRRR HAS A DECENT HANDLE ON VERY SHORT TERM
EVENTS THUS FAR BUT MAY HAVE INITIATED CONVECTION JUST A BIT TOO FAR
NORTH AND EAST BASED ON CURRENT RADAR TRENDS. MADE CORRESPONDING
MINOR ADJUSTMENTS TO POPS FOR THIS. INCREASED AFTERNOON HIGHS JUST A
TAD BASED ON CURRENT TEMPS...WHICH HAVE ALREADY CLIMBED TO WITHIN A
DEGREE OR SO OF ADVERTISED HIGHS. SOME JUICY AIR OUT THERE THIS
AFTERNOON BUT STORMS DO NOT SEEM TO HAVE QUITE THE SAME PUNCH AND
COVERAGE AS YESTERDAY ATTM. ALSO...MID LEVELS DO NOT HAVE AS MUCH DRY
AIR AS YESTERDAY. CONSEQUENTLY DO NOT EXPECT TO SEE AS MANY REPORTS
OF WIND DAMAGE AS YESTERDAY.
UPDATE ISSUED AT 1000 AM EDT WED MAY 28 2014
UPDATED THE FORECAST PACKAGE TO REMOVE FOG AND TO NUDGE HOURLY GRIDS
TOWARDS HOURLY OBS. NO NEW DEVELOPMENTS ATTM. FLASH FLOOD WATCH WILL
REMAIN IN EFFECT FOR THOSE AREAS THAT SAW MOST SIGNIFICANT RAINFALL
YESTERDAY AND THAT HAVE BEST POTENTIAL FOR RAIN TODAY. HRRR STILL
SHOWS CONVECTION FIRING BETWEEN 16-18Z.
UPDATE ISSUED AT 755 AM EDT WED MAY 28 2014
HOURLY GRIDS HAVE BEEN FRESHENED UP FOR THE NEXT FEW HOURS BASED ON
RECENT OBS AND TRENDS IN THE NEAR TERM MODELS. THE HOURLY TEMPS WERE
ADJUSTED UP A BIT THROUGH ABOUT 18Z SIMILAR TO WHAT OCCURRED ON TUE.
THE HRRR RUNS CONTINUE TO SHOW CONVECTION DEVELOPING ABOUT 17Z OR 18Z
WITH THE BEST COVERAGE OVER THE CENTRAL AND EASTERN CWA...OR
LOCATIONS WHERE THE FLASH FLOOD WATCH IS IN EFFECT.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 345 AM EDT WED MAY 28 2014
EARLY THIS MORNING...A WARM AND RATHER MOIST AIRMASS WAS IN PLACE
ACROSS THE REGION. AT MID LEVELS...RIDGING OVER THE SOUTHEASTERN
STATES WAS BEGINNING TO DEPART TO THE SOUTH AND EAST WHILE ANOTHER
RIDGE WAS IN PLACE FROM THE FOUR CORNERS REGION NORTH-EAST INTO PARTS
OF THE CENTRAL PLAINS. IN BETWEEN...OVER THE ARKLATEX REGION A SLOW
MOVING UPPER LOW WAS MEANDERING TOWARD THE LOWER MS VALLEY REGION
WHILE A BROAD TROUGH EXTENDED FROM THE GREAT LAKES INTO THE MID MS
VALLEY REGION. THE WESTERLIES WERE DISPLACED TO THE NORTH OF THE
CENTRAL CONUS...BUT DIPPED SOUTH EAST INTO THE NORTHEASTERN CONUS. AT
THE SFC...AN AREA OF LOW PRESSURE WAS MOVING ACROSS SOUTHEAST NY
STATE WITH A TRAILING SLOW MOVING COLD FRONT WEST INTO THE GREAT
LAKES REGION...BEFORE BECOMING STATIONARY TO A SFC WAVE OVER THE
MIDWEST REGION.
TODAY INTO THURSDAY...THE MID LEVEL TROUGHING WILL GRADUALLY MOVE
SOUTHEAST BUT THE AXIS OF THIS TROUGH SHOULD NOT CROSS THE AREA UNTIL
AROUND THE END OF THE PERIOD. AT THE SAME TIME THE UPPER LOW IS
EXPECTED TO WEAKEN AND MOVE TOWARD THE MS DELTA REGION. OVERALL...THIS
SCENARIO WILL LEAD TO WEAK STEERING FLOW AS CONVECTION TODAY OR
THURSDAY THAT DEVELOPS PRIMARILY AROUND PEAK HEATING IN THE WARM AND
INCREASINGLY MOIST AIRMASS AS THE FRONT NEARS. IF SUFFICIENT HEATING
AND OR MOISTENING OCCURS FOR CAPE TO REACH 2000 J/KG OR MORE THIS
AFTERNOON...A STORM OR TWO MIGHT BECOME MARGINALLY SEVERE AND LEAD TO
DAMAGING WINDS AS OCCURRED ON TUE. STORMS SHOULD ALSO PRODUCE
LOCALLY HEAVY RAIN.
CONVECTION SHOULD BECOME MOST WIDESPREAD AS THE MID LEVEL DISTURBANCE
WORKS ACROSS THE OH VALLEY AND TOWARD THE APPALACHIANS LATE TONIGHT
AND INTO THU AT THE SAME TIME THAT THE COLD FRONT SAGS INTO THE AREA.
FLASH FLOODING WILL BE A CONCERN LATER TODAY AND PERHAPS MORE SO ON
THURSDAY. STORM MOTIONS WILL BE SLOW BOTH DAYS AND PW SHOULD BE AT
ITS HIGHEST ON THURSDAY...NEARING 2 SD ABOVE NORMAL. TRAINING COULD
ALSO OCCUR BOTH DAYS...AGAIN THURSDAY MAY BE THE BIGGER CONCERN
THOUGH AS THE STORM MOTIONS WILL BE NEARLY PARALLEL TO THE SAGGING
COLD FRONT. SINCE PARTS OF THE EASTERN CWA FROM ROWAN AND MORGAN
COUNTIES SOUTHEAST TOWARD PIKE COUNTY ARE ALREADY PRIMED FROM HEAVY
RAIN ON TUESDAY AND FFG VALUES ARE AS LOW AS 1.5 TO 2 INCHES FOR 1
HOUR AND 2 TO 2.5 IN THREE HOURS IN THESE AREAS...WE HAVE OPTED TO
ISSUE A FLASH FLOOD WATCH FROM 2 PM THIS AFTERNOON WHEN CONVECTION
SHOULD REALLY GET GOING THROUGH LATE THU EVENING...AROUND 11
PM...WHEN DRIER AIR SHOULD BE ADVECTING IN FROM THE NORTH BEHIND THE
BOUNDARY AND END THE THREAT.
DIURNAL RANGES SHOULD BE SOMEWHAT LIMITED THROUGH THE PERIOD DUE TO
THE MOIST AIRMASS AND CLOUDS. PATCHY VALLEY FOG SHOULD DISSIPATE BY 9
AM OR SO TODAY...BUT SHOULD DEVELOP AGAIN TONIGHT ESPECIALLY IN
LOCATIONS THAT RECEIVE THE HEAVIER RAINFALL LATER TODAY OR THIS EVENING.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 318 AM EDT WED MAY 28 2014
THE MODELS WERE NOT IN THE BEST OF AGREEMENT THIS GO ROUND IN THE
EXTENDED. THE OVERALL WEATHER PATTERN IN THE MODELS APPEARS TO
FEATURE A LARGE RIDGE OF HIGH PRESSURE ALOFT...WITH MOIST UNSTABLE
AIR BENEATH IT THAT WOULD ACT TO TRIGGER SHOWER AND THUNDERSTORM
ACTIVITY FROM TIME TO TIME THROUGH THE END OF THE PERIOD. WITH A
GOOD DEAL OF UNCERTAINTY IN THE MODEL DATA...DECIDED TO LEAN TOWARD
THE LESS ACTIVE ECMWF MODEL SOLUTION WITH LOWER POPS THAN THE LATEST
MEXMOS GUIDANCE WAS INDICATING. THAT BEING SAID...THE FORECAST WILL
FEATURE PRECIPITATION CHANCES THURSDAY NIGHT THROUGH FRIDAY
AFTERNOON...WITH A BRIEF LULL IN ACTIVITY FRIDAY NIGHT THROUGH LATE
SATURDAY NIGHT AS A SURFACE RIDGE TEMPORARILY TAKES HOLD. ONCE THE
GULF OPENS UP ON SUNDAY...IT APPEARS THERE WILL BE ENOUGH MOISTURE
AND INSTABILITY AVAILABLE TO SPARK SHOWERS AND STORM EACH DAY
THROUGH THE END OF THE EXTENDED PERIOD...WITH THE AFTERNOON AND
EVENING PERIODS BEING THE MOST ACTIVE. THE PERIOD WILL FEEL QUITE
SUMMER LIKE...WITH DAYTIME HIGHS EACH DAY IN THE 80S AND OVERNIGHT
LOWS IN THE 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 800 AM EDT WED MAY 28 2014
AFTER SOME INITIALLY MVFR FOG AT THE TAF SITES AND IFR IN SOME VALLEY
AIRPORTS SUCH AS I39...W38...AND 1A6 THROUGH ABOUT 13Z...CONVECTION
IS EXPECTED TO DEVELOP AROUND 16Z TO 17Z. ALTHOUGH COVERAGE SHOULD
PEAK AND DIMINISH BY 22Z...CHANCES OF CONVECTION WILL LINGER THROUGH
THE END OF THE PERIOD. MVFR TO POSSIBLY IFR FOG SHOULD DEVELOP AT LOZ
AND SME AND OTHER VALLEY LOCATIONS AFTER ABOUT 4Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR KYZ044-050>052-
060-104-106>110-112-113-115-118>120.
&&
$$
UPDATE...RAY
SHORT TERM...JP
LONG TERM...AR
AVIATION...JP
AREA FORECAST DISCUSSION
NWS JACKSON KY
1000 AM EDT WED MAY 28 2014
.UPDATE...
ISSUED AT 1000 AM EDT WED MAY 28 2014
UPDATED THE FORECAST PACKAGE TO REMOVE FOG AND TO NUDGE HOURLY GRIDS
TOWARDS HOURLY OBS. NO NEW DEVELOPMENTS ATTM. FLASH FLOOD WATCH WILL
REMAIN IN EFFECT FOR THOSE AREAS THAT SAW MOST SIGNIFICANT RAINFALL
YESTERDAY AND THAT HAVE BEST POTENTIAL FOR RAIN TODAY. HRRR STILL
SHOWS CONVECTION FIRING BETWEEN 16-18Z.
UPDATE ISSUED AT 755 AM EDT WED MAY 28 2014
HOURLY GRIDS HAVE BEEN FRESHENED UP FOR THE NEXT FEW HOURS BASED ON
RECENT OBS AND TRENDS IN THE NEAR TERM MODELS. THE HOURLY TEMPS WERE
ADJUSTED UP A BIT THROUGH ABOUT 18Z SIMILAR TO WHAT OCCURRED ON TUE.
THE HRRR RUNS CONTINUE TO SHOW CONVECTION DEVELOPING ABOUT 17Z OR 18Z
WITH THE BEST COVERAGE OVER THE CENTRAL AND EASTERN CWA...OR
LOCATIONS WHERE THE FLASH FLOOD WATCH IS IN EFFECT.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 345 AM EDT WED MAY 28 2014
EARLY THIS MORNING...A WARM AND RATHER MOIST AIRMASS WAS IN PLACE
ACROSS THE REGION. AT MID LEVELS...RIDGING OVER THE SOUTHEASTERN
STATES WAS BEGINNING TO DEPART TO THE SOUTH AND EAST WHILE ANOTHER
RIDGE WAS IN PLACE FROM THE FOUR CORNERS REGION NORTH-EAST INTO PARTS
OF THE CENTRAL PLAINS. IN BETWEEN...OVER THE ARKLATEX REGION A SLOW
MOVING UPPER LOW WAS MEANDERING TOWARD THE LOWER MS VALLEY REGION
WHILE A BROAD TROUGH EXTENDED FROM THE GREAT LAKES INTO THE MID MS
VALLEY REGION. THE WESTERLIES WERE DISPLACED TO THE NORTH OF THE
CENTRAL CONUS...BUT DIPPED SOUTH EAST INTO THE NORTHEASTERN CONUS. AT
THE SFC...AN AREA OF LOW PRESSURE WAS MOVING ACROSS SOUTHEAST NY
STATE WITH A TRAILING SLOW MOVING COLD FRONT WEST INTO THE GREAT
LAKES REGION...BEFORE BECOMING STATIONARY TO A SFC WAVE OVER THE
MIDWEST REGION.
TODAY INTO THURSDAY...THE MID LEVEL TROUGHING WILL GRADUALLY MOVE
SOUTHEAST BUT THE AXIS OF THIS TROUGH SHOULD NOT CROSS THE AREA UNTIL
AROUND THE END OF THE PERIOD. AT THE SAME TIME THE UPPER LOW IS
EXPECTED TO WEAKEN AND MOVE TOWARD THE MS DELTA REGION. OVERALL...THIS
SCENARIO WILL LEAD TO WEAK STEERING FLOW AS CONVECTION TODAY OR
THURSDAY THAT DEVELOPS PRIMARILY AROUND PEAK HEATING IN THE WARM AND
INCREASINGLY MOIST AIRMASS AS THE FRONT NEARS. IF SUFFICIENT HEATING
AND OR MOISTENING OCCURS FOR CAPE TO REACH 2000 J/KG OR MORE THIS
AFTERNOON...A STORM OR TWO MIGHT BECOME MARGINALLY SEVERE AND LEAD TO
DAMAGING WINDS AS OCCURRED ON TUE. STORMS SHOULD ALSO PRODUCE
LOCALLY HEAVY RAIN.
CONVECTION SHOULD BECOME MOST WIDESPREAD AS THE MID LEVEL DISTURBANCE
WORKS ACROSS THE OH VALLEY AND TOWARD THE APPALACHIANS LATE TONIGHT
AND INTO THU AT THE SAME TIME THAT THE COLD FRONT SAGS INTO THE AREA.
FLASH FLOODING WILL BE A CONCERN LATER TODAY AND PERHAPS MORE SO ON
THURSDAY. STORM MOTIONS WILL BE SLOW BOTH DAYS AND PW SHOULD BE AT
ITS HIGHEST ON THURSDAY...NEARING 2 SD ABOVE NORMAL. TRAINING COULD
ALSO OCCUR BOTH DAYS...AGAIN THURSDAY MAY BE THE BIGGER CONCERN
THOUGH AS THE STORM MOTIONS WILL BE NEARLY PARALLEL TO THE SAGGING
COLD FRONT. SINCE PARTS OF THE EASTERN CWA FROM ROWAN AND MORGAN
COUNTIES SOUTHEAST TOWARD PIKE COUNTY ARE ALREADY PRIMED FROM HEAVY
RAIN ON TUESDAY AND FFG VALUES ARE AS LOW AS 1.5 TO 2 INCHES FOR 1
HOUR AND 2 TO 2.5 IN THREE HOURS IN THESE AREAS...WE HAVE OPTED TO
ISSUE A FLASH FLOOD WATCH FROM 2 PM THIS AFTERNOON WHEN CONVECTION
SHOULD REALLY GET GOING THROUGH LATE THU EVENING...AROUND 11
PM...WHEN DRIER AIR SHOULD BE ADVECTING IN FROM THE NORTH BEHIND THE
BOUNDARY AND END THE THREAT.
DIURNAL RANGES SHOULD BE SOMEWHAT LIMITED THROUGH THE PERIOD DUE TO
THE MOIST AIRMASS AND CLOUDS. PATCHY VALLEY FOG SHOULD DISSIPATE BY 9
AM OR SO TODAY...BUT SHOULD DEVELOP AGAIN TONIGHT ESPECIALLY IN
LOCATIONS THAT RECEIVE THE HEAVIER RAINFALL LATER TODAY OR THIS EVENING.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 318 AM EDT WED MAY 28 2014
THE MODELS WERE NOT IN THE BEST OF AGREEMENT THIS GO ROUND IN THE
EXTENDED. THE OVERALL WEATHER PATTERN IN THE MODELS APPEARS TO
FEATURE A LARGE RIDGE OF HIGH PRESSURE ALOFT...WITH MOIST UNSTABLE
AIR BENEATH IT THAT WOULD ACT TO TRIGGER SHOWER AND THUNDERSTORM
ACTIVITY FROM TIME TO TIME THROUGH THE END OF THE PERIOD. WITH A
GOOD DEAL OF UNCERTAINTY IN THE MODEL DATA...DECIDED TO LEAN TOWARD
THE LESS ACTIVE ECMWF MODEL SOLUTION WITH LOWER POPS THAN THE LATEST
MEXMOS GUIDANCE WAS INDICATING. THAT BEING SAID...THE FORECAST WILL
FEATURE PRECIPITATION CHANCES THURSDAY NIGHT THROUGH FRIDAY
AFTERNOON...WITH A BRIEF LULL IN ACTIVITY FRIDAY NIGHT THROUGH LATE
SATURDAY NIGHT AS A SURFACE RIDGE TEMPORARILY TAKES HOLD. ONCE THE
GULF OPENS UP ON SUNDAY...IT APPEARS THERE WILL BE ENOUGH MOISTURE
AND INSTABILITY AVAILABLE TO SPARK SHOWERS AND STORM EACH DAY
THROUGH THE END OF THE EXTENDED PERIOD...WITH THE AFTERNOON AND
EVENING PERIODS BEING THE MOST ACTIVE. THE PERIOD WILL FEEL QUITE
SUMMER LIKE...WITH DAYTIME HIGHS EACH DAY IN THE 80S AND OVERNIGHT
LOWS IN THE 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 800 AM EDT WED MAY 28 2014
AFTER SOME INITIALLY MVFR FOG AT THE TAF SITES AND IFR IN SOME VALLEY
AIRPORTS SUCH AS I39...W38...AND 1A6 THROUGH ABOUT 13Z...CONVECTION
IS EXPECTED TO DEVELOP AROUND 16Z TO 17Z. ALTHOUGH COVERAGE SHOULD
PEAK AND DIMINISH BY 22Z...CHANCES OF CONVECTION WILL LINGER THROUGH
THE END OF THE PERIOD. MVFR TO POSSIBLY IFR FOG SHOULD DEVELOP AT LOZ
AND SME AND OTHER VALLEY LOCATIONS AFTER ABOUT 4Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 2 PM EDT THIS AFTERNOON THROUGH THURSDAY
EVENING FOR KYZ044-050>052-060-104-106>110-112-113-115-118>120.
&&
$$
UPDATE...RAY
SHORT TERM...JP
LONG TERM...AR
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
805 AM EDT WED MAY 28 2014
.UPDATE...
ISSUED AT 755 AM EDT WED MAY 28 2014
HOURLY GRIDS HAVE BEEN FRESHENED UP FOR THE NEXT FEW HOURS BASED ON
RECENT OBS AND TRENDS IN THE NEAR TERM MODELS. THE HOURLY TEMPS WERE
ADJUSTED UP A BIT THROUGH ABOUT 18Z SIMILAR TO WHAT OCCURRED ON TUE.
THE HRRR RUNS CONTINUE TO SHOW CONVECTION DEVELOPING ABOUT 17Z OR 18Z
WITH THE BEST COVERAGE OVER THE CENTRAL AND EASTERN CWA...OR
LOCATIONS WHERE THE FLASH FLOOD WATCH IS IN EFFECT.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 345 AM EDT WED MAY 28 2014
EARLY THIS MORNING...A WARM AND RATHER MOIST AIRMASS WAS IN PLACE
ACROSS THE REGION. AT MID LEVELS...RIDGING OVER THE SOUTHEASTERN
STATES WAS BEGINNING TO DEPART TO THE SOUTH AND EAST WHILE ANOTHER
RIDGE WAS IN PLACE FROM THE FOUR CORNERS REGION NORTH-EAT INTO PARTS
OF THE CENTRAL PLAINS. IN BETWEEN...OVER THE ARKLATEX REGION A SLOW
MOVING UPPER LOW WAS MEANDERING TOWARD THE LOWER MS VALLEY REGION
WHILE A BROAD TROUGH EXTENDED FROM THE GREAT LAKES INTO THE MID MS
VALLEY REGION. THE WESTERLIES WERE DISPLACED TO THE NORTH OF THE
CENTRAL CONUS...BUT DIPPED SOUTH EAST INTO THE NORTHEASTERN CONUS. AT
THE SFC...AN AREA OF LOW PRESSURE WAS MOVING ACROSS SOUTHEAST NY
STATE WITH A TRAILING SLOW MOVING COLD FRONT WEST INTO THE GREAT
LAKES REGION...BEFORE BECOMING STATIONARY TO A SFC WAVE OVER THE
MIDWEST REGION.
TODAY INTO THURSDAY...THE MID LEVEL TROUGHING WILL GRADUALLY MOVE
SOUTHEAST BUT THE AXIS OF THIS TROUGH SHOULD NOT CROSS THE AREA UNTIL
AROUND THE END OF THE PERIOD. AT THE SAME TIME THE UPPER LOW IS
EXPECTED TO WEAKEN AND MOVE TOWARD THE MS DELTA REGION. OVERALL...THIS
SCENARIO WILL LEAD TO WEAK STEERING FLOW AS CONVECTION TODAY OR
THURSDAY THAT DEVELOPS PRIMARILY AROUND PEAK HEATING IN THE WARM AND
INCREASINGLY MOIST AIRMASS AS THE FRONT NEARS. IF SUFFICIENT HEATING
AND OR MOISTENING OCCURS FOR CAPE TO REACH 2000 J/KG OR MORE THIS
AFTERNOON...A STORM OR TWO MIGHT BECOME MARGINALLY SEVERE AND LEAD TO
DAMAGING WINDS AS OCCURRED ON TUE. STORMS SHOULD ALSO PRODUCE
LOCALLY HEAVY RAIN.
CONVECTION SHOULD BECOME MOST WIDESPREAD AS THE MID LEVEL DISTURBANCE
WORKS ACROSS THE OH VALLEY AND TOWARD THE APPALACHIANS LATE TONIGHT
AND INTO THU AT THE SAME TIME THAT THE COLD FRONT SAGS INTO THE AREA.
FLASH FLOODING WILL BE A CONCERN LATER TODAY AND PERHAPS MORE SO ON
THURSDAY. STORM MOTIONS WILL BE SLOW BOTH DAYS AND PW SHOULD BE AT
ITS HIGHEST ON THURSDAY...NEARING 2 SD ABOVE NORMAL. TRAINING COULD
ALSO OCCUR BOTH DAYS...AGAIN THURSDAY MAY BE THE BIGGER CONCERN
THOUGH AS THE STORM MOTIONS WILL BE NEARLY PARALLEL TO THE SAGGING
COLD FRONT. SINCE PARTS OF THE EASTERN CWA FROM ROWAN AND MORGAN
COUNTIES SOUTHEAST TOWARD PIKE COUNTY ARE ALREADY PRIMED FROM HEAVY
RAIN ON TUESDAY AND FFG VALUES ARE AS LOW AS 1.5 TO 2 INCHES FOR 1
HOUR AND 2 TO 2.5 IN THREE HOURS IN THESE AREAS...WE HAVE OPTED TO
ISSUE A FLASH FLOOD WATCH FROM 2 PM THIS AFTERNOON WHEN CONVECTION
SHOULD REALLY GET GOING THROUGH LATE THU EVENING...AROUND 11
PM...WHEN DRIER AIR SHOULD BE ADVECTING IN FROM THE NORTH BEHIND THE
BOUNDARY AND END THE THREAT.
DIURNAL RANGES SHOULD BE SOMEWHAT LIMITED THROUGH THE PERIOD DUE TO
THE MOIST AIRMASS AND CLOUDS. PATCHY VALLEY FOG SHOULD DISSIPATE BY 9
AM OR SO TODAY...BUT SHOULD DEVELOP AGAIN TONIGHT ESPECIALLY IN
LOCATIONS THAT RECEIVE THE HEAVIER RAINFALL LATER TODAY OR THIS EVENING.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 318 AM EDT WED MAY 28 2014
THE MODELS WERE NOT IN THE BEST OF AGREEMENT THIS GO ROUND IN THE
EXTENDED. THE OVERALL WEATHER PATTERN IN THE MODELS APPEARS TO
FEATURE A LARGE RIDGE OF HIGH PRESSURE ALOFT...WITH MOIST UNSTABLE
AIR BENEATH IT THAT WOULD ACT TO TRIGGER SHOWER AND THUNDERSTORM
ACTIVITY FROM TIME TO TIME THROUGH THE END OF THE PERIOD. WITH A
GOOD DEAL OF UNCERTAINTY IN THE MODEL DATA...DECIDED TO LEAN TOWARD
THE LESS ACTIVE ECMWF MODEL SOLUTION WITH LOWER POPS THAN THE LATEST
MEXMOS GUIDANCE WAS INDICATING. THAT BEING SAID...THE FORECAST WILL
FEATURE PRECIPITATION CHANCES THURSDAY NIGHT THROUGH FRIDAY
AFTERNOON...WITH A BRIEF LULL IN ACTIVITY FRIDAY NIGHT THROUGH LATE
SATURDAY NIGHT AS A SURFACE RIDGE TEMPORARILY TAKES HOLD. ONCE THE
GULF OPENS UP ON SUNDAY...IT APPEARS THERE WILL BE ENOUGH MOISTURE
AND INSTABILITY AVAILABLE TO SPARK SHOWERS AND STORM EACH DAY
THROUGH THE END OF THE EXTENDED PERIOD...WITH THE AFTERNOON AND
EVENING PERIODS BEING THE MOST ACTIVE. THE PERIOD WILL FEEL QUITE
SUMMER LIKE...WITH DAYTIME HIGHS EACH DAY IN THE 80S AND OVERNIGHT
LOWS IN THE 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 800 AM EDT WED MAY 28 2014
AFTER SOME INITIALLY MVFR FOG AT THE TAF SITES AND IFR IN SOME VALLEY
AIRPORTS SUCH AS I39...W38...AND 1A6 THROUGH ABOUT 13Z...CONVECTION
IS EXPECTED TO DEVELOP AROUND 16Z TO 17Z. ALTHOUGH COVERAGE SHOULD
PEAK AND DIMINISH BY 22Z...CHANCES OF CONVECTION WILL LINGER THROUGH
THE END OF THE PERIOD. MVFR TO POSSIBLY IFR FOG SHOULD DEVELOP AT LOZ
AND SME AND OTHER VALLEY LOCATIONS AFTER ABOUT 4Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 2 PM EDT THIS AFTERNOON THROUGH THURSDAY
EVENING FOR KYZ044-050>052-060-104-106>110-112-113-115-118>120.
&&
$$
UPDATE...JP
SHORT TERM...JP
LONG TERM...AR
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
214 AM EDT WED MAY 28 2014
.UPDATE...
ISSUED AT 140 AM EDT WED MAY 28 2014
THE THUNDERSTORM THAT MOVED INTO THE I 64 CORRIDOR HAS WEAKENED AS IT
MOVED IN EAST KY...WITH JUST SOME LIGHT SHOWERS REMAINING. THE BEST
CHANCES FOR ISOLATED CONVECTION OVERNIGHT WILL BE ACROSS THE NORTH AS
THE REMNANTS OF THE THUNDERSTORM MOVE EAST. ALSO...THE 0Z NAM AND
RECENT HRRR RUNS POINT TOWARD SOME CONVECTION DEVELOPING TOWARD DAWN
ACROSS THE CUMBERLAND VALLEY REGION. FOR THE REST OF THE OVERNIGHT
HAVE ISOLATED TO SCATTERED POPS ACROSS THE FAR NORTH AND ISOLATED
POPS ACROSS THE CUMBERLAND VALLEY. ALTHOUGH A STRAY SHRA OR TSRA IN
BETWEEN CANNOT BE COMPLETELY RULED OUT...PATCHY VALLEY FOG SHOULD BE
THE MAIN FEATURE ALONG WITH DRY WEATHER FOR THE REST OF THE NIGHT IN
THIS AREA. THE CUMBERLAND VALLEY ALREADY HAS SOME FOG OBSERVED AND
THIS THREAT WILL CONTINUE FOR THE REST OF THE OVERNIGHT. WITH THE
HEATING OF THE MOIST AIRMASS IN PLACE...ISOLATED TO SCATTERED
CONVECTION WILL BE POSSIBLE ACROSS MUCH OF THE AREA FROM ABOUT NOON
ON.
UPDATE ISSUED AT 1004 PM EDT TUE MAY 27 2014
RADAR IS QUIET NOW EXCEPT FOR A FEW LEFTOVER SHOWERS NEAR THE MARTIN
COUNTY BORDER WITH WV. CANNOT SOUND THE ALL CLEAR THOUGH AS A STORM
JUST RECENTLY POPPED NEAR BARDSTOWN IN THE LMK CWA AND RECENT HRRR
RUNS HAVE GOTTEN ON BOARD AGAIN WITH SOME ADDITIONAL DEVELOPMENT
LATER TONIGHT. THIS WILL NECESSITATE A CONTINUATION OF 20-30 POPS
THROUGHOUT THE NIGHT.
UPDATE ISSUED AT 738 PM EDT TUE MAY 27 2014
ISOLATED TO WIDELY SCATTERED SHOWERS/STORMS CONTINUE TO FIRE ON
NUMEROUS OUTFLOWS BISECTING THE FORECAST AREA. A FEW OF THESE STORMS
HAVE OVERACHIEVED AND DROPPED SOME TREES...FROM RATHER BENIGN
LOOKING RADAR SIGNATURES. BUT...THE GOOD NEWS IS THAT STORMS SHOULD
BE ON A DOWNWARD TREND SHORTLY NOW THAT THE SUN IS ABOUT TO SET.
FORECAST APPEARS IN GOOD SHAPE AT THIS TIME WITH JUST SOME FINE
TUNING OF NEAR TERM ELEMENTS TO LINE UP WITH CURRENT OBSERVATIONS.
CANNOT RULE OUT A SHOWER OR STORM AT ANYTIME THROUGH THE NIGHT.
HOWEVER...THE HRRR WHICH NAILED THE EARLY MORNING SHOWERS/STORMS
WHICH POPPED UP THIS MORNING IS VOID OF ANY PRECIP OVER OUR AREA
OVERNIGHT. ADDED IN SOME PATCHY FOG TONIGHT AND AGAIN TOMORROW
NIGHT. THIS WILL BE MOST PREVALENT IN AREAS HIT WITH STORMS BUT
CANNOT BE RULED OUT ANYWHERE WITH THE MOIST AIRMASS IN PLACE.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 327 PM EDT TUE MAY 27 2014
WITH LOSS OF DIURNAL HEATING THIS EVENING...EXPECT SCATTERED SHOWERS
AND THUNDERSTORMS TO LOSE STRENGTH AND DIE OUT. AMPLE MOISTURE...AND
THE POTENTIAL FOR AN OVERNIGHT LOW LEVEL JET TO DEVELOP...COULD BE
ENOUGH TO SPAWN SOME ISOLATED SHOWERS AND THUNDERSTORMS AGAIN LATER
DURING THE NIGHT AFTER 6Z. BY TOMORROW...UPPER LEVEL LOW TO OUR SW
WILL SHIFT INTO THE WESTERN TX/LOUISIANA AREA...ALLOWING A COLD
FRONT TO OUR NE TO ALSO PUSH SOUTHWARD AND REACH JUST NE OF THE OHIO
RIVER BY THE AFTERNOON. THIS WILL BE A SLOW PROGRESSING
FRONT...ESPECIALLY AS THE LOW TO OUR SW WILL BECOME NEARLY
STATIONARY OVERNIGHT. IN ADVANCE OF THIS FRONT...ALONG WITH
CONTINUED DIURNAL HEATING AND INSTABILITY...EXPECT MORE SHOWERS AND
THUNDERSTORMS TO DEVELOP BY LATE MORNING/EARLY AFTERNOON TOMORROW.
THERE ALSO LOOKS TO BE A SLIGHTLY BETTER SHEAR PROFILE IN
PLACE...THOUGH STILL NOT OVERLY IMPRESSIVE. EITHER WAY...EXPECT ANY
DEVELOPMENT TOMORROW TO BE SLIGHTLY HIGHER IN COVERAGE AND INTENSITY
COMPARED TO TODAY. SOME HEAVY DOWNPOURS...HIGH GUSTS...AND SMALL
HAIL CANNOT BE RULED OUT ONCE AGAIN.
AS SEEMS TO BE THE TREND...WITH LOSS OF DIURNAL HEATING OVERNIGHT
TOMORROW NIGHT EXPECT STORMS TO BEGIN A DIMINISHING TREND AFTER
NIGHTFALL. HOWEVER...UNLIKE TONIGHT...THE INCOMING COLD FRONT WILL
CONTINUE TO PROVIDE DECENT FORCING IN ADDITION TO AN ALREADY MOIST
ENVIRONMENT. SO WHILE STORMS MAY DIMINISH IN COVERAGE IN THE
EVENING...SOME ISOLATED TO SCATTERED CONVECTION COULD STILL CONTINUE
THROUGH THE ENTIRETY OF THE NIGHT. TEMPERATURE TRENDS WILL CONTINUE
FROM PREVIOUS DAYS...WITH SOUTHERLY FLOW FROM THE GULF BRINGING IN
WARM HUMID AIR. OVERNIGHT LOWS WILL BE IN THE LOW 60S...AND DAYTIME
HIGHS IN THE LOW 80S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 425 PM EDT TUE MAY 27 2014
THE MODELS REMAIN IN GOOD AGREEMENT WITH A RATHER BLOCKY LONG WAVE
PATTERN TO REMAIN IN PLACE THROUGH EARLY NEXT WEEK. AN UPPER LEVEL
LOW WILL START OUT CHURNING ACROSS LOUISIANA...WITH A RIDGE BUILDING
ACROSS THE PLAINS. MEANWHILE...AN UPPER LEVEL TROUGH WILL BE SWINGING
THROUGH THE PACIFIC NORTHWEST...AS WELL AS ANOTHER MOVING THROUGH
SOUTHEASTERN CANADA. THE UPPER LEVEL RIDGE WILL BUILD IN ACROSS THE
OHIO VALLEY THROUGH THIS WEEKEND...WITH THE GULF UPPER LEVEL LOW
FADING AWAY. TROUGHING WILL SHARPEN UP ON BOTH SIDES OF THE RIDGE...
SHUNTING IT FURTHER SOUTH BY EARLY NEXT WEEK.
FOR EASTERN KENTUCKY...A WEAK BACKDOOR COLD FRONT WILL APPROACH AND
EVENTUALLY MOVE THROUGH THE AREA THURSDAY INTO FRIDAY. POPS WILL PEAK
ON THURSDAY...WITH SCATTERED TO NUMEROUS CONVECTION EXPECTED. ONCE
THE BOUNDARY EXITS AND WEAKENS INTO THE TENNESSEE VALLEY BY FRIDAY
EVENING...EXPECT A BRIEF DRY PERIOD OF DRY WEATHER THROUGH SUNDAY
MORNING. ENOUGH WEAKNESS IN THE RIDGE BY SUNDAY AFTERNOON WILL ALLOW
FOR A RETURN OF ISOLATED CONVECTION. ANOTHER FRONTAL BOUNDARY WILL
APPROACH FROM THE NORTH MONDAY THROUGH TUESDAY...ALLOWING FOR BETTER
CHANCES OF SHOWERS AND STORMS.
TEMPERATURES WILL CONTINUE TO AVERAGE ABOVE NORMAL THROUGH THE
PERIOD...WITH HIGHS MAINLY IN THE LOW TO MID 80S AND LOWS IN THE 50S
AND 60S. THE HUMIDITY WILL SUBSIDE A BIT BY THE FIRST HALF OF THE
WEEKEND...AND THEN LOOKS TO BUILD BACK IN AS WE HEAD INTO EARLY NEXT
WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 140 AM EDT WED MAY 28 2014
MOST LOCATIONS SHOULD REMAIN DRY...BUT IN THE WARM SECTOR...CANNOT
RULE OUT A SHRA OR TSRA OVERNIGTH IN A COUPLE OF SPOTS...BUT ATTM...
CHANCES ARE TO LOW TO INCLUDE IN THE TAFS OVERNIGHT. COVERAGE OF
CONVECTION SHOULD RAMP UP AFTER 15Z OR 16Z AND LINGER THROUGH THE
END OF THE PERIOD. OTHERWISE...PENDING CLOUD OCVER...MVFR TO IFR
FOG...POSSIBLY BELOW AIRPORT MINS AT SOME OF THE NON TAF TIES SUCH AS
EKQ...W39...AND I39 WILL LINGER THROUGH ABOUT 13Z...BEFORE LIFTING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...JMW
LONG TERM...GEOGERIAN
AVIATION...JP
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1224 PM CDT WED MAY 28 2014
.AVIATION...
UPPER LVL LOW OVHD. VERY MOIST AIRMASS PRODUCING SCATTERED
CONVECTION OF MAINLY SMALL DIAMETER CELLS OF MDT/HEAVY RAIN.
OCNL LTG EXPECTED THIS AFTN. MORE EXTENSIVE MVFR CIGS OVER
NORTH LA..LIMITING AFTN HEATING WITH MOSTLY LIGHT RAIN EXPECTED
FROM CLOUD DECKS. CONVECTION INCREASING MOST RAPIDLY SW AR...WITH
EASTERLY MOVEMENT AROUND NORTH SIDE OF UPPER LOW...WITH THIS
ACTIVITY POSSIBLY MOVING INTO KTXK TERMINAL ARA THIS AFTN.
MEANWHILE...CONVECTION OVER NE TX...TO THE WEST OF UPPER LOW...WILL
MOVE SLOWLY SWD. KTYR...KGGG...AND KLFK MAY REMAIN IN VCNTY OF
THIS CONVECTION. LOW VFR CIGS WILL REDUCE TO MOSTLY MVFR...WITH
SOME IFR CIG AND FOG ALSO POSSIBLE LATE TONIGHT. HOWEVER...NE TX
IN MORE NORTHERLY FLOW...MAY REMAIN MOSTLY VFR OVERNIGHT./VII/
&&
.PREV DISCUSSION... /ISSUED 944 AM CDT WED MAY 28 2014/
DISCUSSION...
WATER VAPOR IMAGERY THIS MORNING SHOWS OUT CUTOFF LOW SPINNING IN
THE VICINITY OF EXTREME NE TX/SE OK AND SW AR...MOVING VERY SLOWLY
TO THE SOUTH AND EAST. DRIER AIR IS TRYING FILL IN ACROSS SE TX
INTO SW LA IN THE WAKE OF EXTENSIVE OUTFLOW BOUNDARY ALONG THE SE
TX COAST INTO S LA ATTM. REGIONAL RADAR MOSAICS IS DEPICTING A
WEAK MCV SPINNING JUST SOUTHEAST OF AEX WITH THIS FEATURE MOVING
VERY SLOWLY NORTHEAST THIS MORNING. VISIBLE SATELLITE IMAGERY
SHOWING BREAKS IN THE OVC ACROSS NE TX THIS MORNING AS WELL.
FOR THE UPDATE...FOLLOWED THE HRRR OUTPUT CLOSELY FOR THE
REMAINDER OF THE DAYTIME HOURS WHICH SUGGESTS THAT OUR EASTERN
PARISHES INTO SOUTH CENTRAL ARKANSAS WILL REMAIN WET WHILE
CONVECTION ACROSS THE REMAINDER OF THE REGION WILL BE TIED TO ANY
LATE MORNING/AFTERNOON HEATING OUR REGION RECEIVES. THEREFORE...
KEPT CATEGORICAL POPS GOING ACROSS OUR EASTERN ZONES...TAPERING
POPS BACK TO SCATTERED VARIETY ACROSS OUR WEST AND NORTHWEST
ZONES.
CONCERNING TEMPERATURES...DID NOT MAKE MANY CHANGES AS OUR WEST
AND NORTHWEST ZONES SHOULD SEE THE GREATEST WARMUP THIS AFTERNOON.
DID LOWER OUR EASTERN ZONES A FEW DEGREES GIVEN THE LARGE CANOPY
OF RAIN EXPECTED FOR MUCH OF THE DAY.
OTHER CHANGES WERE COSMETIC INCLUDING DEWPOINT AND WIND GRIDS TO
MIMIC CURRENT/EXPECTED TRENDS.
UPDATED FORECAST OUT SHORTLY...13.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 81 67 82 68 85 / 60 40 60 30 40
MLU 78 67 82 66 86 / 80 60 70 30 60
DEQ 79 64 81 66 83 / 30 30 50 30 30
TXK 79 65 81 66 83 / 50 30 50 30 40
ELD 77 65 81 66 84 / 80 50 60 30 40
TYR 81 66 81 67 84 / 30 30 30 30 40
GGG 81 66 82 67 84 / 30 30 40 30 40
LFK 81 67 83 68 85 / 50 40 60 30 40
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
944 AM CDT WED MAY 28 2014
.DISCUSSION...
WATER VAPOR IMAGERY THIS MORNING SHOWS OUT CUTOFF LOW SPINNING IN
THE VICINITY OF EXTREME NE TX/SE OK AND SW AR...MOVING VERY SLOWLY
TO THE SOUTH AND EAST. DRIER AIR IS TRYING FILL IN ACROSS SE TX
INTO SW LA IN THE WAKE OF EXTENSIVE OUTFLOW BOUNDARY ALONG THE SE
TX COAST INTO S LA ATTM. REGIONAL RADAR MOSAICS IS DEPICTING A
WEAK MCV SPINNING JUST SOUTHEAST OF AEX WITH THIS FEATURE MOVING
VERY SLOWLY NORTHEAST THIS MORNING. VISIBLE SATELLITE IMAGERY
SHOWING BREAKS IN THE OVC ACROSS NE TX THIS MORNING AS WELL.
FOR THE UPDATE...FOLLOWED THE HRRR OUTPUT CLOSELY FOR THE
REMAINDER OF THE DAYTIME HOURS WHICH SUGGESTS THAT OUR EASTERN
PARISHES INTO SOUTH CENTRAL ARKANSAS WILL REMAIN WET WHILE
CONVECTION ACROSS THE REMAINDER OF THE REGION WILL BE TIED TO ANY
LATE MORNING/AFTERNOON HEATING OUR REGION RECEIVES. THEREFORE...
KEPT CATEGORICAL POPS GOING ACROSS OUR EASTERN ZONES...TAPERING
POPS BACK TO SCATTERED VARIETY ACROSS OUR WEST AND NORTHWEST
ZONES.
CONCERNING TEMPERATURES...DID NOT MAKE MANY CHANGES AS OUR WEST
AND NORTHWEST ZONES SHOULD SEE THE GREATEST WARMUP THIS AFTERNOON.
DID LOWER OUR EASTERN ZONES A FEW DEGREES GIVEN THE LARGE CANOPY
OF RAIN EXPECTED FOR MUCH OF THE DAY.
OTHER CHANGES WERE COSMETIC INCLUDING DEWPOINT AND WIND GRIDS TO
MIMIC CURRENT/EXPECTED TRENDS.
UPDATED FORECAST OUT SHORTLY...13.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 81 67 82 68 85 / 60 40 60 30 40
MLU 78 67 82 66 86 / 80 60 70 30 60
DEQ 79 64 81 66 83 / 30 30 50 30 30
TXK 79 65 81 66 83 / 50 30 50 30 40
ELD 77 65 81 66 84 / 80 50 60 30 40
TYR 81 66 81 67 84 / 30 30 30 30 40
GGG 81 66 82 67 84 / 30 30 40 30 40
LFK 81 67 83 68 85 / 50 40 60 30 40
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
13
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
648 AM EDT WED MAY 28 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHEAST UNITED STATES TODAY
BEFORE MOVING THE MID-ATLANTIC REGION TONIGHT. THE FRONT WILL PUSH
SOUTH OF THE AREA THURSDAY WITH HIGH PRESSURE RIDGING DOWN THE
NEW ENGLAND AND MID-ATLANTIC COAST. HIGH PRESSURE WILL REMAIN OVER
THE REGION THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHORTWAVE EMBEDDED WITHIN NORTHWEST FLOW ALOFT COMBINED WITH SOME
ELEVATED INSTABILITY AND MOISTURE CONVERGENCE WAS SUPPORTING
NUMEROUS SHOWERS WELL INTO THE NIGHT FROM WESTERN MARYLAND INTO
CENTRAL MARYLAND. HRRR HAS COME IN LINE WITH LATEST RADAR
TRENDS...AND LATEST WRF-ARW WAS ALSO STARTING TO CATCH ON.
RADAR TRENDS/LATEST HIGH RESOLUTION GUIDANCE SERVE AS THE BASIS FOR
POPS/WX FOR THE OVERNIGHT PERIOD WITH SHOWERS PERSISTING THROUGH
NIGHT...POSSIBLY BRUSHING NORTHERN VIRGINIA/DC. POPS HAVE BEEN
ADJUSTED ACCORDINGLY. GIVEN THE HIGH MOISTURE CONTENT...ISOLATED
SHOWERS FURTHER SOUTH INTO THE CWA CAN/T BE RULED OUT EITHER.
HIGH RESOLUTION GUIDANCE SUGGESTS A RELATIVE MINIMUM NEAR
DAYBREAK/EARLY MORNING. POPS WILL TREND BACK DOWN FOR A TIME...BUT
STILL CAN/T RULE OUT A FEW SHOWERS ACROSS THE NORTHERN PORTION OF
THE CWA IN THE CONVERGENCE ZONE.
ON A BROADER VIEW...COLD FRONT WAS SINKING SOUTH INTO NORTHERN
PENNSYLVANIA AT 07Z. THERE WAS ALSO CONVECTION ALONG/AHEAD OF THIS
BOUNDARY. THE FRONT WILL SAG SOUTHWARD THROUGH THE DAY
TODAY...LIKELY PRESSING SOUTH OF THE MASON DIXON LINE INTO
NORTHERN/CENTRAL MARYLAND LATE IN THE AFTERNOON.
MUCH OF THE CWA WILL RESIDE IN THE WARM/MOIST SECTOR FOR THE BALANCE
OF THE DAY. SIMILAR TO YESTERDAY...WHILE SHEAR WILL BE ON THE WEAK
SIDE THERE WILL BE CAPE AT LEAST ON THE ORDER OF 500 TO 1000 J/KG
WITH POCKETS OF HIGHER CAPE POSSIBLE IN AREAS WITH BREAKS IN THE
CLOUD COVER. FACTOR IN WEAK SHORTWAVES IN NORTHWEST FLOW AND THE
FRONTAL BOUNDARY...EXPECT AN UPTICK IN CONVECTION BY MIDDAY/EARLY
AFTERNOON SUPPORTIVE OF LIKELY POPS.
STORMS MAY BE PULSE IN NATURE...AND A FEW STORMS COULD PRODUCE
LOCALLY DAMAGING WIND GUSTS AND LARGE HAIL AND THIS WILL BE
INTRODUCED INTO THE HWO. IF INITIATION OCCURS BEYOND MID
AFTERNOON...IT/S POSSIBLE THAT NORTHEAST MARYLAND WILL BE SPARED OF
THE ISOLATED SEVERE RISK DUE TO MORE STABLE AIR PUNCHING SOUTHWARD
BEHIND THE BACKDOOR FRONT BUT CURRENTLY PREFER A SLOWER FRONTAL
PROGRESSION PER THE GFS RATHER THAN THE NAM.
MAV AND MET CONTINUE TO DIFFER FOR MAXIMA TODAY...BUT THE GAP HAS
SHRUNK COMPARED TO YESTERDAY. WARMER MAV WAS THE WINNER YESTERDAY
AND WILL LEAN IN THIS DIRECTION TODAY AS MUCH OF THE AREA WILL
RESIDE TO THE SOUTH OF THE FRONT TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
FRONTAL BOUNDARY CONTINUES TO SLIDE SOUTHWARD THROUGH THE CWA
TONIGHT...AND THEN WILL RESIDE SOUTH OF THE CWA ON THURSDAY AS HIGH
PRESSURE ALONG THE NEW ENGLAND COAST EXTENDS SOUTH TOWARD THE
MID-ATLANTIC.
CONVECTION WILL LIKELY BE ONGOING THIS EVENING...BUT PER SREFS WILL
TREND POPS FOR SHOWERS DOWNWARD ACROSS THE NORTHEAST PORTION OF THE
CWA. SREFS ALSO SHOWS PROBABILITIES FOR ANY INSTABILITY OF
SIGNIFICANCE BEING SHOVED SOUTHWARD THROUGH THE NIGHT AND INTO
THURSDAY WHICH WILL ELIMINATE THE RISK FOR THUNDER EXCEPT PERHAPS
THE FAR SOUTHWEST PORTION OF THE CWA. IN FACT...WITH AN EASTERLY
FLOW DEVELOPING TONIGHT INTO THURSDAY...LINGERING SHOWERY
PRECIPITATION MAY MORPH INTO A LIGHT RAIN OR DRIZZLE TYPE SCENARIO
INTO THURSDAY.
FOR TEMPERATURES...STUCK CLOSE TO MAV/MET FOR MINIMA/MAXIMA WHICH
CAPTURE THE EASTERLY FLOW/MARINE LAYER SCENARIO WELL AND SHOW A
SMALL DIURNAL RANGE FROM TONIGHT INTO THURSDAY. LOOKS LIKE THE CWA
WILL BE STUCK IN THE 60S DURING THE DAYTIME ON THURSDAY.
BACKDOOR COLD FRONT WILL CONTINUE TO PROGRESS FARTHER TO OUR SOUTH
THU NGT. FCST SOUNDINGS SHOW THE COLUMN DRYING IN THE MID LVLS BUT
MOISTURE REMAINS TRAPPED IN THE LLVLS BENEATH THE MID-LVL SUBSIDENCE
INVERSION. THIS WILL RESULT IN CLOUDS AND POCKETS OF RAIN LINGERING
INTO THE EVE AND EVEN INTO THE OVNGT IN THE NRN PIEDMONT AND
POTOMAC HIGHLANDS.
NLY FLOW IN ASSOCIATED WITH WEAK HIPRES WILL CONTINUE TO DRY OUT THE
COLUMN ON FRI. DAYTIME MIXING THOUGH WILL LIKELY LEAD TO A WELL-
DEVELOPED CU FIELD DURING THE AFTN. MAX TEMPS IN THE 70S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
LARGE-SCALE PATTERN THIS WEEKEND WILL FEATURE AN UPPER LOW OFF
THE NEW ENGLAND COAST AND UPSTREAM UPPER RIDGE BUILDING OVER
MIDWEST AND GULF COAST STATES. AT THE SFC...BROAD AREA OF HIPRES
OVER ERN CANADA AND GREAT LAKES WILL BE LOCATED BETWEEN BOTH OF
THE AFOREMENTIONED UPPER FEATURES. THE SFC HIGH IS FORECAST TO
BUILD DOWN INTO THE MID-ATLANTIC REGION ON SATURDAY BEFORE THE
CENTER OF THE HIGH SHIFTS TOWARD THE ERN SEABOARD SATURDAY NGT AND
SUNDAY.
CONTINENTAL POLAR AIRMASS OVERHEAD ON SATURDAY UNDER NLY WINDS
AROUND THE HIGH. COOL AIRMASS WILL BE MODERATED BY STRONG DIURNAL
HEATING...YIELDING MAX TEMPS NEAR NORMAL IN THE 70S. LLVL WINDS
EVENTUALLY VEER OUT OF THE EAST SATURDAY NGT AND OUT OF THE
SOUTHEAST ON SUNDAY AS THE SFC HIGH AXIS SHIFTS EWD TOWARD THE
COAST. PATTERN RECOGNITION HINTS AT THE POSSIBILITY FOR CLOUDS TO
DEVELOP OFFSHORE AND ADVECT INLAND OF THE CHSPK BAY LATE SATURDAY
NIGHT WITH A COMBINATION OF ONSHORE LLVL FLOW AND LIFT FROM
SHORTWAVE ENERGY ROTATING SWD ALONG THE WRN PERIPHERY OF THE UPPER
LOW. MODEL DIFFERENCES REMAIN REGARDING THE WWD EXTENT OF THESE
FEATURES SO CONFIDENCE NOT QUITE HIGH ENOUGH YET TO GO WITH A CLOUDY
FORECAST FOR SATURDAY NIGHT. NEAR NORMAL TEMPS WILL PERSIST
SATURDAY NIGHT AND SUNDAY.
SLY RETURN FLOW WILL STRENGTHEN OVER THE AREA EARLY NEXT WEEK AS THE
CENTER OF SFC HIPRES SHIFTS OFF THE SOUTHEAST COAST. WLY WINDS ALOFT
AROUND THE UPPER RIDGE WILL ADVECT WARM AIR INTO THE MID-ATLANTIC
REGION WHILE THE SLY FLOW AT THE SFC TRANSPORTS MOISTURE UP THE
ERN SEABOARD. A RETURN OF HEAT AND HUMIDITY WILL BE ACCOMPANIED
BY INCREASING CHANCES FOR SHOWERS AND STORMS EACH DAY...ESPECIALLY
TOWARD THE MIDDLE OF THE WEEK WHEN THE UPPER RIDGE IS FORECAST TO
FLATTEN...RESULTING IN THE STORM TRACK SHIFTING SWD AND CLOSER TO
OUR LATITUDE.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
EARLY MORNING SHOWERS ARE LIKELY ALONG/NORTH OF A MRB-BWI LINE.
LATEST HIGH RES GUIDANCE SUGGESTS NOTHING MORE THAN ISOLATED SHOWERS
BY DAYBREAK...BUT EXPECT AN INCREASE IN SHRA/TSRA ACTIVITY BY
MIDDAY/EARLY AFTERNOON AS A FRONT APPROACHES FROM THE NORTH. IMPACT
AT TERMINALS MAY OCCUR A LITTLE SOONER THAN WHAT OCCURRED
YESTERDAY...AND IS REFLECTED IN TAFS HIGHLIGHTING THE 18Z-22Z
PERIOD.
TAF ALSO REFLECTS OTHER CHANGES...FIRST A WIND SHIFT TO THE EAST IN
THE LATE AFTERNOON/EVENING AS THE FRONT PRESSES TO THE SOUTH AND
THEN LOWERING CEILINGS AS EASTERLY FLOW ADVECTS A MARINE LAYER.
LEANED TOWARD A GFS/LAMP/SREFS BLEND FOR ONSET OF MVFR/IFR CIGS
OVERNIGHT. IFR CIGS MAY CONTINUE THROUGH THE DAY ON THURSDAY.
BACKDOOR BOUNDARY WILL CONTINUE TO PUSH SOUTH OF THE TERMINALS THU
NGT. FLIGHT RESTRICTIONS POSSIBLE WITH LOW CLOUDS ON THE COLD SIDE
OF THE BOUNDARY. POTENTIAL FOR IFR CIGS INCREASE FARTHER SOUTH AND
WEST TOWARD MRB-CHO WHERE LLVL MOISTURE WILL BE HARDER TO SCOUR OUT.
MVFR CIGS FAVORED AT IAD/DCA/BWI/MTN.
FCST SOUNDINGS FROM THE GFS/NAM INDICATE CIGS NEAR MVFR-VFR CRITERIA
FRI AFTN WHEN CU FIELD DEVELOPS. VFR EXPECT THIS WEEKEND WITH HIPRES
OVERHEAD.
&&
.MARINE...
WEAK GRADIENT TODAY WILL KEEP WINDS BELOW SCA CRITERIA ALTHOUGH
AFTERNOON THUNDERSTORMS COULD PRODUCE STRONG GUSTY WINDS. COLD FRONT
WILL SINK SOUTHWARD THROUGH THE WATERS THIS EVENING. WIND SHIFT TO
THE EAST OCCURS AND MODELS SHOW WINDS INCREASING TO 15 TO 20 KT THUS
SCA IS IN EFFECT. THIS IS LIKELY TO CONTINUE INTO THE FIRST PART OF
THURSDAY BEFORE WINDS DIMINISH.
NELY WINDS 5-10 KT THU NGT BECOME LGT AND VAR FRI WITH WEAK HIPRES
OVERHEAD.
SCA CONDITIONS POSSIBLE FOR PORTIONS OF THE WATERS ON SAT IN
ASSOCIATION WITH PRESSURE RISES RESULTING FROM HIPRES BUILDING IN
FROM THE GREAT LAKES. SCA WOULD BE MORE LIKELY IN THE MAIN STEM OF
THE CHSPK BAY WHERE ORIENTATION OF NLY WINDS OPTIMAL FOR CHANNELING.
&&
.TIDES/COASTAL FLOODING...
WATER LEVELS WERE RUNNING NEAR NORMAL OVERNIGHT...AND WILL REMAIN
THAT WAY THROUGH MUCH OF THE DAY. HOWEVER...AS WINDS BECOME EAST AND
INCREASE TO 15 TO 20 KT BEHIND A COLD FRONT THIS EVENING ANOMALIES
ARE EXPECTED TO QUICKLY INCREASE. WITH ASTRONOMICAL TIDES STILL ON
THE HIGH SIDE...WILL HAVE TO KEEP A CLOSE EYE ON SENSITIVE LOCATIONS
SUCH AS ANNAPOLIS BEGINNING WITH THE THURSDAY MORNING HIGH TIDE
CYCLE.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 2 PM EDT
THURSDAY FOR ANZ530>534-537>543.
SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 6 AM EDT
THURSDAY FOR ANZ535-536.
&&
$$
SYNOPSIS...JRK/BPP
NEAR TERM...BPP
SHORT TERM...JRK/BPP
LONG TERM...JRK
AVIATION...JRK/BPP
MARINE...JRK/BPP
TIDES/COASTAL FLOODING...BPP
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
357 AM EDT WED MAY 28 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHEAST UNITED STATES TODAY
BEFORE MOVING THE MID-ATLANTIC REGION TONIGHT. THE FRONT WILL PUSH
SOUTH OF THE AREA THURSDAY WITH HIGH PRESSURE RIDGING DOWN THE
NEW ENGLAND AND MID-ATLANTIC COAST. HIGH PRESSURE WILL REMAIN OVER
THE REGION THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHORTWAVE EMBEDDED WITHIN NORTHWEST FLOW ALOFT COMBINED WITH SOME
ELEVATED INSTABILITY AND MOISTURE CONVERGENCE WAS SUPPORTING
NUMEROUS SHOWERS WELL INTO THE NIGHT FROM WESTERN MARYLAND INTO
CENTRAL MARYLAND. HRRR HAS COME IN LINE WITH LATEST RADAR
TRENDS...AND LATEST WRF-ARW WAS ALSO STARTING TO CATCH ON.
RADAR TRENDS/LATEST HIGH RESOLUTION GUIDANCE SERVE AS THE BASIS FOR
POPS/WX FOR THE OVERNIGHT PERIOD WITH SHOWERS PERSISTING THROUGH
NIGHT...POSSIBLY BRUSHING NORTHERN VIRGINIA/DC. POPS HAVE BEEN
ADJUSTED ACCORDINGLY. GIVEN THE HIGH MOISTURE CONTENT...ISOLATED
SHOWERS FURTHER SOUTH INTO THE CWA CAN/T BE RULED OUT EITHER.
HIGH RESOLUTION GUIDANCE SUGGESTS A RELATIVE MINIMUM NEAR
DAYBREAK/EARLY MORNING. POPS WILL TREND BACK DOWN FOR A TIME...BUT
STILL CAN/T RULE OUT A FEW SHOWERS ACROSS THE NORTHERN PORTION OF
THE CWA IN THE CONVERGENCE ZONE.
ON A BROADER VIEW...COLD FRONT WAS SINKING SOUTH INTO NORTHERN
PENNSYLVANIA AT 07Z. THERE WAS ALSO CONVECTION ALONG/AHEAD OF THIS
BOUNDARY. THE FRONT WILL SAG SOUTHWARD THROUGH THE DAY
TODAY...LIKELY PRESSING SOUTH OF THE MASON DIXON LINE INTO
NORTHERN/CENTRAL MARYLAND LATE IN THE AFTERNOON.
MUCH OF THE CWA WILL RESIDE IN THE WARM/MOIST SECTOR FOR THE BALANCE
OF THE DAY. SIMILAR TO YESTERDAY...WHILE SHEAR WILL BE ON THE WEAK
SIDE THERE WILL BE CAPE AT LEAST ON THE ORDER OF 500 TO 1000 J/KG
WITH POCKETS OF HIGHER CAPE POSSIBLE IN AREAS WITH BREAKS IN THE
CLOUD COVER. FACTOR IN WEAK SHORTWAVES IN NORTHWEST FLOW AND THE
FRONTAL BOUNDARY...EXPECT AN UPTICK IN CONVECTION BY MIDDAY/EARLY
AFTERNOON SUPPORTIVE OF LIKELY POPS.
STORMS MAY BE PULSE IN NATURE...AND A FEW STORMS COULD PRODUCE
LOCALLY DAMAGING WIND GUSTS AND LARGE HAIL AND THIS WILL BE
INTRODUCED INTO THE HWO. IF INITIATION OCCURS BEYOND MID
AFTERNOON...IT/S POSSIBLE THAT NORTHEAST MARYLAND WILL BE SPARED OF
THE ISOLATED SEVERE RISK DUE TO MORE STABLE AIR PUNCHING SOUTHWARD
BEHIND THE BACKDOOR FRONT BUT CURRENTLY PREFER A SLOWER FRONTAL
PROGRESSION PER THE GFS RATHER THAN THE NAM.
MAV AND MET CONTINUE TO DIFFER FOR MAXIMA TODAY...BUT THE GAP HAS
SHRUNK COMPARED TO YESTERDAY. WARMER MAV WAS THE WINNER YESTERDAY
AND WILL LEAN IN THIS DIRECTION TODAY AS MUCH OF THE AREA WILL
RESIDE TO THE SOUTH OF THE FRONT TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
FRONTAL BOUNDARY CONTINUES TO SLIDE SOUTHWARD THROUGH THE CWA
TONIGHT...AND THEN WILL RESIDE SOUTH OF THE CWA ON THURSDAY AS HIGH
PRESSURE ALONG THE NEW ENGLAND COAST EXTENDS SOUTH TOWARD THE
MID-ATLANTIC.
CONVECTION WILL LIKELY BE ONGOING THIS EVENING...BUT PER SREFS WILL
TREND POPS FOR SHOWERS DOWNWARD ACROSS THE NORTHEAST PORTION OF THE
CWA. SREFS ALSO SHOWS PROBABILITIES FOR ANY INSTABILITY OF
SIGNIFICANCE BEING SHOVED SOUTHWARD THROUGH THE NIGHT AND INTO
THURSDAY WHICH WILL ELIMINATE THE RISK FOR THUNDER EXCEPT PERHAPS
THE FAR SOUTHWEST PORTION OF THE CWA. IN FACT...WITH AN EASTERLY
FLOW DEVELOPING TONIGHT INTO THURSDAY...LINGERING SHOWERY
PRECIPITATION MAY MORPH INTO A LIGHT RAIN OR DRIZZLE TYPE SCENARIO
INTO THURSDAY.
FOR TEMPERATURES...STUCK CLOSE TO MAV/MET FOR MINIMA/MAXIMA WHICH
CAPTURE THE EASTERLY FLOW/MARINE LAYER SCENARIO WELL AND SHOW A
SMALL DIURNAL RANGE FROM TONIGHT INTO THURSDAY. LOOKS LIKE THE CWA
WILL BE STUCK IN THE 60S DURING THE DAYTIME ON THURSDAY.
BACKDOOR COLD FRONT WILL CONTINUE TO PROGRESS FARTHER TO OUR SOUTH
THU NGT. FCST SOUNDINGS SHOW THE COLUMN DRYING IN THE MID LVLS BUT
MOISTURE REMAINS TRAPPED IN THE LLVLS BENEATH THE MID-LVL SUBSIDENCE
INVERSION. THIS WILL RESULT IN CLOUDS AND POCKETS OF RAIN LINGERING
INTO THE EVE AND EVEN INTO THE OVNGT IN THE NRN PIEDMONT AND
POTOMAC HIGHLANDS.
NLY FLOW IN ASSOCIATED WITH WEAK HIPRES WILL CONTINUE TO DRY OUT THE
COLUMN ON FRI. DAYTIME MIXING THOUGH WILL LIKELY LEAD TO A WELL-
DEVELOPED CU FIELD DURING THE AFTN. MAX TEMPS IN THE 70S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
LARGE-SCALE PATTERN THIS WEEKEND WILL FEATURE AN UPPER LOW OFF
THE NEW ENGLAND COAST AND UPSTREAM UPPER RIDGE BUILDING OVER
MIDWEST AND GULF COAST STATES. AT THE SFC...BROAD AREA OF HIPRES
OVER ERN CANADA AND GREAT LAKES WILL BE LOCATED BETWEEN BOTH OF
THE AFOREMENTIONED UPPER FEATURES. THE SFC HIGH IS FORECAST TO
BUILD DOWN INTO THE MID-ATLANTIC REGION ON SATURDAY BEFORE THE
CENTER OF THE HIGH SHIFTS TOWARD THE ERN SEABOARD SATURDAY NGT AND
SUNDAY.
CONTINENTAL POLAR AIRMASS OVERHEAD ON SATURDAY UNDER NLY WINDS
AROUND THE HIGH. COOL AIRMASS WILL BE MODERATED BY STRONG DIURNAL
HEATING...YIELDING MAX TEMPS NEAR NORMAL IN THE 70S. LLVL WINDS
EVENTUALLY VEER OUT OF THE EAST SATURDAY NGT AND OUT OF THE
SOUTHEAST ON SUNDAY AS THE SFC HIGH AXIS SHIFTS EWD TOWARD THE
COAST. PATTERN RECOGNITION HINTS AT THE POSSIBILITY FOR CLOUDS TO
DEVELOP OFFSHORE AND ADVECT INLAND OF THE CHSPK BAY LATE SATURDAY
NIGHT WITH A COMBINATION OF ONSHORE LLVL FLOW AND LIFT FROM
SHORTWAVE ENERGY ROTATING SWD ALONG THE WRN PERIPHERY OF THE UPPER
LOW. MODEL DIFFERENCES REMAIN REGARDING THE WWD EXTENT OF THESE
FEATURES SO CONFIDENCE NOT QUITE HIGH ENOUGH YET TO GO WITH A CLOUDY
FORECAST FOR SATURDAY NIGHT. NEAR NORMAL TEMPS WILL PERSIST
SATURDAY NIGHT AND SUNDAY.
SLY RETURN FLOW WILL STRENGTHEN OVER THE AREA EARLY NEXT WEEK AS THE
CENTER OF SFC HIPRES SHIFTS OFF THE SOUTHEAST COAST. WLY WINDS ALOFT
AROUND THE UPPER RIDGE WILL ADVECT WARM AIR INTO THE MID-ATLANTIC
REGION WHILE THE SLY FLOW AT THE SFC TRANSPORTS MOISTURE UP THE
ERN SEABOARD. A RETURN OF HEAT AND HUMIDITY WILL BE ACCOMPANIED
BY INCREASING CHANCES FOR SHOWERS AND STORMS EACH DAY...ESPECIALLY
TOWARD THE MIDDLE OF THE WEEK WHEN THE UPPER RIDGE IS FORECAST TO
FLATTEN...RESULTING IN THE STORM TRACK SHIFTING SWD AND CLOSER TO
OUR LATITUDE.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
EARLY MORNING SHOWERS ARE LIKELY ALONG/NORTH OF A MRB-BWI LINE.
LATEST HIGH RES GUIDANCE SUGGESTS NOTHING MORE THAN ISOLATED SHOWERS
BY DAYBREAK...BUT EXPECT AN INCREASE IN SHRA/TSRA ACTIVITY BY
MIDDAY/EARLY AFTERNOON AS A FRONT APPROACHES FROM THE NORTH. IMPACT
AT TERMINALS MAY OCCUR A LITTLE SOONER THAN WHAT OCCURRED
YESTERDAY...AND IS REFLECTED IN TAFS HIGHLIGHTING THE 18Z-22Z
PERIOD.
TAF ALSO REFLECTS OTHER CHANGES...FIRST A WIND SHIFT TO THE EAST IN
THE LATE AFTERNOON/EVENING AS THE FRONT PRESSES TO THE SOUTH AND
THEN LOWERING CEILINGS AS EASTERLY FLOW ADVECTS A MARINE LAYER.
LEANED TOWARD A GFS/LAMP/SREFS BLEND FOR ONSET OF MVFR/IFR CIGS
OVERNIGHT. IFR CIGS MAY CONTINUE THROUGH THE DAY ON THURSDAY.
BACKDOOR BOUNDARY WILL CONTINUE TO PUSH SOUTH OF THE TERMINALS THU
NGT. FLIGHT RESTRICTIONS POSSIBLE WITH LOW CLOUDS ON THE COLD SIDE
OF THE BOUNDARY. POTENTIAL FOR IFR CIGS INCREASE FARTHER SOUTH AND
WEST TOWARD MRB-CHO WHERE LLVL MOISTURE WILL BE HARDER TO SCOUR OUT.
MVFR CIGS FAVORED AT IAD/DCA/BWI/MTN.
FCST SOUNDINGS FROM THE GFS/NAM INDICATE CIGS NEAR MVFR-VFR CRITERIA
FRI AFTN WHEN CU FIELD DEVELOPS. VFR EXPECT THIS WEEKEND WITH HIPRES
OVERHEAD.
&&
.MARINE...
WEAK GRADIENT TODAY WILL KEEP WINDS BELOW SCA CRITERIA ALTHOUGH
AFTERNOON THUNDERSTORMS COULD PRODUCE STRONG GUSTY WINDS. COLD FRONT
WILL SINK SOUTHWARD THROUGH THE WATERS THIS EVENING. WIND SHIFT TO
THE EAST OCCURS AND MODELS SHOW WINDS INCREASING TO 15 TO 20 KT THUS
SCA IS IN EFFECT. THIS IS LIKELY TO CONTINUE INTO THE FIRST PART OF
THURSDAY BEFORE WINDS DIMINISH.
NELY WINDS 5-10 KT THU NGT BECOME LGT AND VAR FRI WITH WEAK HIPRES
OVERHEAD.
SCA CONDITIONS POSSIBLE FOR PORTIONS OF THE WATERS ON SAT IN
ASSOCIATION WITH PRESSURE RISES RESULTING FROM HIPRES BUILDING IN
FROM THE GREAT LAKES. SCA WOULD BE MORE LIKELY IN THE MAIN STEM OF
THE CHSPK BAY WHERE ORIENTATION OF NLY WINDS OPTIMAL FOR CHANNELING.
&&
.TIDES/COASTAL FLOODING...
WATER LEVELS WERE RUNNING NEAR NORMAL OVERNIGHT...AND WILL REMAIN
THAT WAY THROUGH MUCH OF THE DAY. HOWEVER...AS WINDS BECOME EAST AND
INCREASE TO 15 TO 20 KT BEHIND A COLD FRONT THIS EVENING ANOMALIES
ARE EXPECTED TO QUICKLY INCREASE. WITH ASTRONOMICAL TIDES STILL ON
THE HIGH SIDE...WILL HAVE TO KEEP A CLOSE EYE ON SENSITIVE LOCATIONS
SUCH AS ANNAPOLIS BEGINNING WITH THE THURSDAY MORNING HIGH TIDE
CYCLE.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM EDT
THURSDAY FOR ANZ530>534-537>543.
SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 6 AM EDT
THURSDAY FOR ANZ535-536.
&&
$$
SYNOPSIS...JRK/BPP
NEAR TERM...BPP
SHORT TERM...JRK/BPP
LONG TERM...JRK
AVIATION...JRK/BPP
MARINE...JRK/BPP
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
117 PM EDT WED MAY 28 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 330 AM EDT WED MAY 28 2014
A SLOW MOVING FRONTAL SYSTEM WILL EXIT THE AREA TO THE SOUTH TODAY.
A FEW SHOWERS AND EVEN A THUNDERSTORM WILL REMAIN POSSIBLE INTO MID
AFTERNOON ACROSS THE SOUTH BEFORE RAIN MOVES ENTIRELY OUT OF THE
AREA.
AN AREA OF HIGH PRESSURE WILL THEN BUILD IN ACROSS THE AREA BY
THURSDAY AND REMAIN IN CONTROL OF THE WEATHER THROUGH A GOOD PORTION
OF THE WEEKEND. THE THREAT OF SHOWERS AND STORMS WILL THEN INCREASE
DURING THE LATTER HALF OF THE WEEKEND AND INTO EARLY NEXT WEEK. MILD
WEATHER IS EXPECTED TO CONTINUE FOR THE AREA.
&&
.UPDATE...
ISSUED AT 1130 AM EDT WED MAY 28 2014
I HAVE ONCE AGAIN UPDATED THE FORECAST TO REFLECT THE LOCALLY
HEAVY RAINFALL CURRENTLY OCCURRING OVER MOSTLY CLINTON COUNTY.
OUR FFMP IS SHOWING AROUND 1.8 INCHES OF RAIN NEAR BAD CREEK. A
NEARBY MESONET STATION SHOWS THE DUAL POL PRECIPITATION IS VERY
CLOSE TO WHAT THE RADAR SHOWS. THE RAINFALL IS IN AN ENHANCED LIFT
AREA IN FRONT OF THE SHORTWAVE TRACKING THROUGH EXTREME SOUTHWEST
LOWER MICHIGAN AT THIS TIME. IT SHOULD BE FAR ENOUGH TO OUR
SOUTHEAST TO ALLOW THE RAIN TO END BY EARLY THIS AFTERNOON.
OTHERWISE I EXPECT THE CLEARING TO CONTINUE TO PROGRESS FROM
NORTHEAST TO SOUTHWEST AS THE DRY AIR COMES IN FROM THE CANADIAN
HIGH TO OUR NORTH.
I DO NOT EXPECT MUCH IN THE WAY OF THUNDERSTORM ACTIVITY THIS
AFTERNOON AS THERE IS NOT ENOUGH INSTABILITY.
UPDATE ISSUED AT 857 AM EDT WED MAY 28 2014
I ADDED FOG TO THE SOUTHERN ROW OF COUNTIES INTO LATE MORNING AS
WE HAVE REPORTS OF LOCALLY LOW VISIBILITIES AND THE ASOS STATIONS
NEAR AND SOUTH OF I-94 HAVE VISIBILITIES UNDER 3 MILES. I EXPECT AS
WINDS BECOME MORE STRONGLY NORTHEAST ALL OF THAT SHOULD CLEAR OUT
BY LATE MORNING.
THE HRRR FROM THE 09Z RUN SHOWS THE AREA OF SHOWERS DEVELOPING
SIGNIFICANTLY NEAR I-96 AS THE SHORTWAVE MOVES THROUGH OUR
SOUTHWEST CWA DURING THE MID TO LATE MORNING. THE RAP 11Z RUN
SHOWS THE RAIN ALREADY THERE MOVING OUT BY LATE MORNING. GIVEN OUR
RADAR LOOPS SHOWS THE SHOWERS INCREASING I HAVE TO BELIEVE OUR
SOUTHERN ROW OF COUNTIES SHOULD SEE SOME RAIN MID TO LATE
MORNING... WHICH OF COURSE WOULD HELP TO KEEP VISIBILITIES DOWN SO
WE HAVE 60 POPS THERE FOR NOW. THE SURGE OF DRY AIR FROM THE
NORTHEAST SHOULD CLEAR ALL AREAS OUT (NE TO SW ) THIS AFTERNOON
INTO THIS EVENING.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 330 AM EDT WED MAY 28 2014
THE ONLY WEATHER OF NOTE IN THE SHORT TERM REALLY IS CONFINED TO THE
FIRST 12 HRS OR SO OF THE FCST IN THE FORM OF RAIN/THUNDER CHANCES.
THE COLD FRONT HAS SLIPPED SOUTH OF THE CWFA...HOWEVER SOME RAIN HAS
BEEN DEVELOPING EARLY THIS MORNING NE OF GRAND RAPIDS ACROSS CENTRAL
LOWER MI. A MOIST AIR MASS REMAINS IN PLACE EARLY THIS MORNING WITH
PWATS STILL AROUND 1.6 INCHES ACROSS THE SRN HALF OF THE CWFA. IN
ADDITION...A WEAK SHORT WAVE IN THE WEAK UPPER FLOW IS POISED TO
MOVE THROUGH THE AREA THROUGH EARLY AFTERNOON. WE EXPECT THAT THERE
WILL BE A DECENT THREAT OF SOME PATCHES OF RAIN SHOWERS AND AN LOW
CHC OF AN EMBEDDED RUMBLE OF THUNDER THAT WILL SHIFT SOUTH THROUGH
TIME FROM ITS CURRENT POSITION.
MOST MODEL GUIDANCE IS IN AGREEMENT THAT ANY RAIN ACROSS THE CWFA
THIS MORNING SHOULD END BY MID AFTERNOON AS THE SHORT WAVE WILL
SHIFT SE OF THE AREA AFTER 18Z THIS AFTERNOON. THE MOIST AIR MASS
WILL SHIFT SOUTH OF THE AREA...ALLOWING FOR DRIER ADVECTION TO TAKE
PLACE. THERE IS NOT A WHOLE LOT OF COOLER AIR BEHIND THIS
SYSTEM...SO MOST AREAS WILL MAKE IT BACK INTO THE 70S WITH H850
TEMPS REMAINING IN THE LOWER TEENS C.
WE THEN EXPECT DRY CONDITIONS THROUGH THE REMAINDER OF THE SHORT
TERM WITH MILD TEMPERATURES HOLDING IN. THE SHORT WAVE ACROSS THE
AREA THIS MORNING AND THE WAVE NEAR THE QUAD CITIES WILL EACH DAMPEN
OUT BY THU. THIS OCCURS AS THE UPPER LOW OFF OF THE PACIFIC NW MOVES
INLAND AND HELPS TO BUILD THE UPPER RIDGE JUST TO OUR WEST. THE
RIDGE WILL SLOWLY BUILD...AND THE RIDGE AXIS WILL ONLY APPROACH THE
STATE BY FRI. TEMPS WILL GO UP A NOTCH EACH DAY AS H850 TEMPS INCH
UP A DEGREE OR SO EACH DAY. WE COULD SEE 80 ONCE AGAIN BY FRI.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 AM EDT WED MAY 28 2014
QUIET AND PLEASANT WEATHER IS EXPECTED FOR THE UPCOMING WEEKEND WITH
SUMMER-LIKE TEMPERATURES AND COMFORTABLE HUMIDITY LEVELS. THIS IS A
HIGH CONFIDENCE FORECAST AS HIGH PRESSURE DOMINATES BOTH ALOFT AND
AT THE SURFACE. ISOLATED TSTMS CANNOT BE RULED OUT ON SUNDAY AS THE
UPPER RIDGE BEGINS TO FLATTEN OUT AND ALLOWS SOME SHORTWAVE ENERGY
TO SNEAK IN FROM THE WEST. HOWEVER THE BETTER CHANCE OF STORMS
SHOULD HOLD OFF UNTIL EARLY NEXT WEEK.
POTENTIALLY ACTIVE PATTERN DEVELOPS FOR MONDAY AND TUESDAY OF NEXT
WEEK AS A QUASI STATIONARY SURFACE FRONT SETS UP ACROSS THE AREA.
VERY WARM AND HUMID AIR MASS SHOULD RESULT IN MODERATELY UNSTABLE
ENVIRONMENT NEAR THE FRONT AS SERIES OF SHORTWAVES/SFC LOWS MOVE
ALONG IT. THE SET UP LOOKS CONDUCIVE TO PERIODS/AREAS OF LOCALLY
HEAVY RAINFALL AND PERHAPS A ROUND OR TWO OF SEVERE WEATHER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 117 PM EDT WED MAY 28 2014
A COLD FRONT HAD DROPPED INTO NORTHERN INDIANA AS OF 17Z. HOWEVER
A BAND OF CLOUDS PERSISTED ACROSS SOUTHERN LOWER MI BEHIND THE
FRONT. THESE CLOUDS WERE SHOWING SIGN OF BREAKING UP ACROSS
WISCONSIN AND LAKE MICHIGAN AS DRIER AIR CONTINUES TO MOVE INTO
THIS REGION. EXPECT THE SAME TO SLOWLY HAPPEN ACROSS SOUTHERN
LOWER MI LATE AFTERNOON INTO THE EVENING.
THE CEILINGS WERE VFR ACROSS I-96...BUT MVFR ACROSS I-94. EXPECT
LITTLE OVERALL CHANGE TO THIS PATTERN FOR THE AFTERNOON...THEN A
SLOW IMPROVEMENT IS EXPECTED OVERNIGHT. EXPECT A MIX OF VFR AND
MVFR BY DAYBREAK THU...BECOMING ALL VFR BY MID/LATE THU MORNING.
&&
.MARINE...
ISSUED AT 330 AM EDT WED MAY 28 2014
THE MAIN ITEM OF INTEREST FOR MARINERS IS THE ONGOING POTENTIAL OF
FOG FOR THE NEARSHORE WATERS FOR TODAY. A LOOK AT WEBCAMS ALONG THE
COAST AND VISIBILITY REPORTS ALONG THE COAST INDICATE THAT FOG IS
NOT A WIDESPREAD PROBLEM THIS MORNING. THERE IS SOME FLOATING AROUND
OUT THERE...BUT NOT EVERYWHERE. WE WILL CONTINUE THE MENTION OF FOG
EARLY BEFORE MUCH DRIER AIR ADVECTS IN THIS AFTERNOON.
WINDS AND WAVES DO NOT LOOK TO BE MUCH OF AN ISSUE WITH WINDS
REMAINING AROUND OR BELOW 15 KNOTS THROUGH THE END OF THE WEEK.
&&
.HYDROLOGY...
ISSUED AT 128 PM EDT TUE MAY 27 2014
RIVER LEVELS CONTINUE TO DECLINE...WITH THE EXCEPTION OF SYCAMORE
CREEK AT HOLT. SOME RIVER LEVELS HAVE EXHIBITED SLOWER RATES OF
DECLINE FOLLOWING LAST NIGHT`S RAINFALL. RAINFALL FROM SCATTERED
SHOWERS AND STORMS THIS AFTERNOON AND EVENING MAY HAVE A SIMILAR
EFFECT. A QUARTER TO HALF INCH OF RAIN IS POSSIBLE...WITH LOCALLY
HIGHER AMOUNTS IN THUNDERSTORMS. THE THUNDERSTORMS WILL BE SLOW
MOVING...ALLOWING THE POTENTIAL FOR HEAVY RAINFALL.
RIVER ADVISORIES CONTINUE AT MAPLE RAPIDS, IONIA, AND EAGLE. ALL 3
ARE ON THE DECLINE...BUT EFFICIENT RAIN PRODUCING THUNDERSTORMS
LATER THIS AFTERNOON AND EVENING MAY DELAY THE FALL OF THOSE RIVERS
BACK BELOW BANKFULL.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...MEADE
AVIATION...JK
HYDROLOGY...EBW
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1130 AM EDT WED MAY 28 2014
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 330 AM EDT WED MAY 28 2014
A SLOW MOVING FRONTAL SYSTEM WILL EXIT THE AREA TO THE SOUTH TODAY.
A FEW SHOWERS AND EVEN A THUNDERSTORM WILL REMAIN POSSIBLE INTO MID
AFTERNOON ACROSS THE SOUTH BEFORE RAIN MOVES ENTIRELY OUT OF THE
AREA.
AN AREA OF HIGH PRESSURE WILL THEN BUILD IN ACROSS THE AREA BY
THURSDAY AND REMAIN IN CONTROL OF THE WEATHER THROUGH A GOOD PORTION
OF THE WEEKEND. THE THREAT OF SHOWERS AND STORMS WILL THEN INCREASE
DURING THE LATTER HALF OF THE WEEKEND AND INTO EARLY NEXT WEEK. MILD
WEATHER IS EXPECTED TO CONTINUE FOR THE AREA.
&&
.UPDATE...
ISSUED AT 1130 AM EDT WED MAY 28 2014
I HAVE ONCE AGAIN UPDATED THE FORECAST TO REFLECT THE LOCALLY
HEAVY RAINFALL CURRENTLY OCCURRING OVER MOSTLY CLINTON COUNTY.
OUR FFMP IS SHOWING AROUND 1.8 INCHES OF RAIN NEAR BAD CREEK. A
NEARBY MESONET STATION SHOWS THE DUAL POL PRECIPITATION IS VERY
CLOSE TO WHAT THE RADAR SHOWS. THE RAINFALL IS IN AN ENHANCED LIFT
AREA IN FRONT OF THE SHORTWAVE TRACKING THROUGH EXTREME SOUTHWEST
LOWER MICHIGAN AT THIS TIME. IT SHOULD BE FAR ENOUGH TO OUR
SOUTHEAST TO ALLOW THE RAIN TO END BY EARLY THIS AFTERNOON.
OTHERWISE I EXPECT THE CLEARING TO CONTINUE TO PROGRESS FROM
NORTHEAST TO SOUTHWEST AS THE DRY AIR COMES IN FROM THE CANADIAN
HIGH TO OUR NORTH.
I DO NOT EXPECT MUCH IN THE WAY OF THUNDESTORM ACTIVITY THIS
AFTERNOON AS THERE IS NOT ENOUGH INSTABLITY.
UPDATE ISSUED AT 857 AM EDT WED MAY 28 2014
I ADDED FOG TO THE SOUTHERN ROW OF COUNTIES INTO LATE MORNING AS
WE HAVE REPORTS OF LOCALLY LOW VISIBILITIES AND THE ASOS STATIONS
NEAR AND SOUTH OF I-94 HAVE VISIBILITIES UNDER 3 MILES. I EXPECT AS
WINDS BECOME MORE STRONGLY NORTHEAST ALL OF THAT SHOULD CLEAR OUT
BY LATE MORNING.
THE HRRR FROM THE 09Z RUN SHOWS THE AREA OF SHOWERS DEVELOPING
SIGNIFICANTLY NEAR I-96 AS THE SHORTWAVE MOVES THROUGH OUR
SOUTHWEST CWA DURING THE MID TO LATE MORNING. THE RAP 11Z RUN
SHOWS THE RAIN ALREADY THERE MOVING OUT BY LATE MORNING. GIVEN OUR
RADAR LOOPS SHOWS THE SHOWERS INCREASING I HAVE TO BELIEVE OUR
SOUTHERN ROW OF COUNTIES SHOULD SEE SOME RAIN MID TO LATE
MORNING... WHICH OF COURSE WOULD HELP TO KEEP VISIBILITIES DOWN SO
WE HAVE 60 POPS THERE FOR NOW. THE SURGE OF DRY AIR FROM THE
NORTHEAST SHOULD CLEAR ALL AREAS OUT (NE TO SW ) THIS AFTERNOON
INTO THIS EVENING.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 330 AM EDT WED MAY 28 2014
THE ONLY WEATHER OF NOTE IN THE SHORT TERM REALLY IS CONFINED TO THE
FIRST 12 HRS OR SO OF THE FCST IN THE FORM OF RAIN/THUNDER CHANCES.
THE COLD FRONT HAS SLIPPED SOUTH OF THE CWFA...HOWEVER SOME RAIN HAS
BEEN DEVELOPING EARLY THIS MORNING NE OF GRAND RAPIDS ACROSS CENTRAL
LOWER MI. A MOIST AIR MASS REMAINS IN PLACE EARLY THIS MORNING WITH
PWATS STILL AROUND 1.6 INCHES ACROSS THE SRN HALF OF THE CWFA. IN
ADDITION...A WEAK SHORT WAVE IN THE WEAK UPPER FLOW IS POISED TO
MOVE THROUGH THE AREA THROUGH EARLY AFTERNOON. WE EXPECT THAT THERE
WILL BE A DECENT THREAT OF SOME PATCHES OF RAIN SHOWERS AND AN LOW
CHC OF AN EMBEDDED RUMBLE OF THUNDER THAT WILL SHIFT SOUTH THROUGH
TIME FROM ITS CURRENT POSITION.
MOST MODEL GUIDANCE IS IN AGREEMENT THAT ANY RAIN ACROSS THE CWFA
THIS MORNING SHOULD END BY MID AFTERNOON AS THE SHORT WAVE WILL
SHIFT SE OF THE AREA AFTER 18Z THIS AFTERNOON. THE MOIST AIR MASS
WILL SHIFT SOUTH OF THE AREA...ALLOWING FOR DRIER ADVECTION TO TAKE
PLACE. THERE IS NOT A WHOLE LOT OF COOLER AIR BEHIND THIS
SYSTEM...SO MOST AREAS WILL MAKE IT BACK INTO THE 70S WITH H850
TEMPS REMAINING IN THE LOWER TEENS C.
WE THEN EXPECT DRY CONDITIONS THROUGH THE REMAINDER OF THE SHORT
TERM WITH MILD TEMPERATURES HOLDING IN. THE SHORT WAVE ACROSS THE
AREA THIS MORNING AND THE WAVE NEAR THE QUAD CITIES WILL EACH DAMPEN
OUT BY THU. THIS OCCURS AS THE UPPER LOW OFF OF THE PACIFIC NW MOVES
INLAND AND HELPS TO BUILD THE UPPER RIDGE JUST TO OUR WEST. THE
RIDGE WILL SLOWLY BUILD...AND THE RIDGE AXIS WILL ONLY APPROACH THE
STATE BY FRI. TEMPS WILL GO UP A NOTCH EACH DAY AS H850 TEMPS INCH
UP A DEGREE OR SO EACH DAY. WE COULD SEE 80 ONCE AGAIN BY FRI.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 AM EDT WED MAY 28 2014
QUIET AND PLEASANT WEATHER IS EXPECTED FOR THE UPCOMING WEEKEND WITH
SUMMERLIKE TEMPERATURES AND COMFORTABLE HUMIDITY LEVELS. THIS IS A
HIGH CONFIDENCE FORECAST AS HIGH PRESSURE DOMINATES BOTH ALOFT AND
AT THE SURFACE. ISOLATED TSTMS CANNOT BE RULED OUT ON SUNDAY AS THE
UPPER RIDGE BEGINS TO FLATTEN OUT AND ALLOWS SOME SHORTWAVE ENERGY
TO SNEAK IN FROM THE WEST. HOWEVER THE BETTER CHANCE OF STORMS
SHOULD HOLD OFF UNTIL EARLY NEXT WEEK.
POTENTIALLY ACTIVE PATTERN DEVELOPS FOR MONDAY AND TUESDAY OF NEXT
WEEK AS A QUASI STATIONARY SURFACE FRONT SETS UP ACROSS THE AREA.
VERY WARM AND HUMID AIR MASS SHOULD RESULT IN MODERATELY UNSTABLE
ENVIRONMENT NEAR THE FRONT AS SERIES OF SHORTWAVES/SFC LOWS MOVE
ALONG IT. THE SET UP LOOKS CONDUCIVE TO PERIODS/AREAS OF LOCALLY
HEAVY RAINFALL AND PERHAPS A ROUND OR TWO OF SEVERE WEATHER.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 749 AM EDT WED MAY 28 2014
WIDESPREAD IFR SOUTH OF I-96 EARLY THIS MORNING SHOULD IMPROVE TO
MOSTLY MVFR CONDITIONS BY MID MORNING. RAIN SHOWERS ARE EXPECTED
TO BECOME MORE NUMEROUS ACROSS THIS SAME AREA BY MID MORNING AND
CONTINUE THROUGH EARLY AFTERNOON. CONDITIONS SHOULD THEN TURN VFR
FROM NORTH TO SOUTH AFTER 18Z... WITH WIDESPREAD VFR LIKELY
TONIGHT AS DRIER AIR GRADUALLY WORKS IN.
&&
.MARINE...
ISSUED AT 330 AM EDT WED MAY 28 2014
THE MAIN ITEM OF INTEREST FOR MARINERS IS THE ONGOING POTENTIAL OF
FOG FOR THE NEARSHORE WATERS FOR TODAY. A LOOK AT WEBCAMS ALONG THE
COAST AND VISIBILITY REPORTS ALONG THE COAST INDICATE THAT FOG IS
NOT A WIDESPREAD PROBLEM THIS MORNING. THERE IS SOME FLOATING AROUND
OUT THERE...BUT NOT EVERYWHERE. WE WILL CONTINUE THE MENTION OF FOG
EARLY BEFORE MUCH DRIER AIR ADVECTS IN THIS AFTERNOON.
WINDS AND WAVES DO NOT LOOK TO BE MUCH OF AN ISSUE WITH WINDS
REMAINING AROUND OR BELOW 15 KNOTS THROUGH THE END OF THE WEEK.
&&
.HYDROLOGY...
ISSUED AT 128 PM EDT TUE MAY 27 2014
RIVER LEVELS CONTINUE TO DECLINE...WITH THE EXCEPTION OF SYCAMORE
CREEK AT HOLT. SOME RIVER LEVELS HAVE EXHIBITED SLOWER RATES OF
DECLINE FOLLOWING LAST NIGHT`S RAINFALL. RAINFALL FROM SCATTERED
SHOWERS AND STORMS THIS AFTERNOON AND EVENING MAY HAVE A SIMILAR
EFFECT. A QUARTER TO HALF INCH OF RAIN IS POSSIBLE...WITH LOCALLY
HIGHER AMOUNTS IN THUNDERSTORMS. THE THUNDERSTORMS WILL BE SLOW
MOVING...ALLOWING THE POTENTIAL FOR HEAVY RAINFALL.
RIVER ADVISORIES CONTINUE AT MAPLE RAPIDS, IONIA, AND EAGLE. ALL 3
ARE ON THE DECLINE...BUT EFFICIENT RAIN PRODUCING THUNDERSTORMS
LATER THIS AFTERNOON AND EVENING MAY DELAY THE FALL OF THOSE RIVERS
BACK BELOW BANKFULL.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...EBW
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
857 AM EDT WED MAY 28 2014
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 330 AM EDT WED MAY 28 2014
A SLOW MOVING FRONTAL SYSTEM WILL EXIT THE AREA TO THE SOUTH TODAY.
A FEW SHOWERS AND EVEN A THUNDERSTORM WILL REMAIN POSSIBLE INTO MID
AFTERNOON ACROSS THE SOUTH BEFORE RAIN MOVES ENTIRELY OUT OF THE
AREA.
AN AREA OF HIGH PRESSURE WILL THEN BUILD IN ACROSS THE AREA BY
THURSDAY AND REMAIN IN CONTROL OF THE WEATHER THROUGH A GOOD PORTION
OF THE WEEKEND. THE THREAT OF SHOWERS AND STORMS WILL THEN INCREASE
DURING THE LATTER HALF OF THE WEEKEND AND INTO EARLY NEXT WEEK. MILD
WEATHER IS EXPECTED TO CONTINUE FOR THE AREA.
&&
.UPDATE...
ISSUED AT 857 AM EDT WED MAY 28 2014
I ADDED FOG TO THE SOUTHERN ROW OF COUNTIES INTO LATE MORNING AS
WE HAVE REPORTS OF LOCALLY LOW VISIBILITIES AND THE ASOS STATIONS
NEAR AND SOUTH OF I-94 HAVE VISIBILITIES UNDER 3 MILES. I EXPECT AS
WINDS BECOME MORE STRONGLY NORTHEAST ALL OF THAT SHOULD CLEAR OUT
BY LATE MORNING.
THE HRRR FROM THE 09Z RUN SHOWS THE AREA OF SHOWERS DEVELOPING
SIGNIFICANTLY NEAR I-96 AS THE SHORTWAVE MOVES THROUGH OUR
SOUTHWEST CWA DURING THE MID TO LATE MORNING. THE RAP 11Z RUN
SHOWS THE RAIN ALREADY THERE MOVING OUT BY LATE MORNING. GIVEN OUR
RADAR LOOPS SHOWS THE SHOWERS INCREASING I HAVE TO BELIEVE OUR
SOUTHERN ROW OF COUNTIES SHOULD SEE SOME RAIN MID TO LATE
MORNING... WHICH OF COURSE WOULD HELP TO KEEP VISIBILITIES DOWN SO
WE HAVE 60 POPS THERE FOR NOW. THE SURGE OF DRY AIR FROM THE
NORTHEAST SHOULD CLEAR ALL AREAS OUT (NE TO SW ) THIS AFTERNOON
INTO THIS EVENING.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 330 AM EDT WED MAY 28 2014
THE ONLY WEATHER OF NOTE IN THE SHORT TERM REALLY IS CONFINED TO THE
FIRST 12 HRS OR SO OF THE FCST IN THE FORM OF RAIN/THUNDER CHANCES.
THE COLD FRONT HAS SLIPPED SOUTH OF THE CWFA...HOWEVER SOME RAIN HAS
BEEN DEVELOPING EARLY THIS MORNING NE OF GRAND RAPIDS ACROSS CENTRAL
LOWER MI. A MOIST AIR MASS REMAINS IN PLACE EARLY THIS MORNING WITH
PWATS STILL AROUND 1.6 INCHES ACROSS THE SRN HALF OF THE CWFA. IN
ADDITION...A WEAK SHORT WAVE IN THE WEAK UPPER FLOW IS POISED TO
MOVE THROUGH THE AREA THROUGH EARLY AFTERNOON. WE EXPECT THAT THERE
WILL BE A DECENT THREAT OF SOME PATCHES OF RAIN SHOWERS AND AN LOW
CHC OF AN EMBEDDED RUMBLE OF THUNDER THAT WILL SHIFT SOUTH THROUGH
TIME FROM ITS CURRENT POSITION.
MOST MODEL GUIDANCE IS IN AGREEMENT THAT ANY RAIN ACROSS THE CWFA
THIS MORNING SHOULD END BY MID AFTERNOON AS THE SHORT WAVE WILL
SHIFT SE OF THE AREA AFTER 18Z THIS AFTERNOON. THE MOIST AIR MASS
WILL SHIFT SOUTH OF THE AREA...ALLOWING FOR DRIER ADVECTION TO TAKE
PLACE. THERE IS NOT A WHOLE LOT OF COOLER AIR BEHIND THIS
SYSTEM...SO MOST AREAS WILL MAKE IT BACK INTO THE 70S WITH H850
TEMPS REMAINING IN THE LOWER TEENS C.
WE THEN EXPECT DRY CONDITIONS THROUGH THE REMAINDER OF THE SHORT
TERM WITH MILD TEMPERATURES HOLDING IN. THE SHORT WAVE ACROSS THE
AREA THIS MORNING AND THE WAVE NEAR THE QUAD CITIES WILL EACH DAMPEN
OUT BY THU. THIS OCCURS AS THE UPPER LOW OFF OF THE PACIFIC NW MOVES
INLAND AND HELPS TO BUILD THE UPPER RIDGE JUST TO OUR WEST. THE
RIDGE WILL SLOWLY BUILD...AND THE RIDGE AXIS WILL ONLY APPROACH THE
STATE BY FRI. TEMPS WILL GO UP A NOTCH EACH DAY AS H850 TEMPS INCH
UP A DEGREE OR SO EACH DAY. WE COULD SEE 80 ONCE AGAIN BY FRI.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 AM EDT WED MAY 28 2014
QUIET AND PLEASANT WEATHER IS EXPECTED FOR THE UPCOMING WEEKEND WITH
SUMMERLIKE TEMPERATURES AND COMFORTABLE HUMIDITY LEVELS. THIS IS A
HIGH CONFIDENCE FORECAST AS HIGH PRESSURE DOMINATES BOTH ALOFT AND
AT THE SURFACE. ISOLATED TSTMS CANNOT BE RULED OUT ON SUNDAY AS THE
UPPER RIDGE BEGINS TO FLATTEN OUT AND ALLOWS SOME SHORTWAVE ENERGY
TO SNEAK IN FROM THE WEST. HOWEVER THE BETTER CHANCE OF STORMS
SHOULD HOLD OFF UNTIL EARLY NEXT WEEK.
POTENTIALLY ACTIVE PATTERN DEVELOPS FOR MONDAY AND TUESDAY OF NEXT
WEEK AS A QUASI STATIONARY SURFACE FRONT SETS UP ACROSS THE AREA.
VERY WARM AND HUMID AIR MASS SHOULD RESULT IN MODERATELY UNSTABLE
ENVIRONMENT NEAR THE FRONT AS SERIES OF SHORTWAVES/SFC LOWS MOVE
ALONG IT. THE SET UP LOOKS CONDUCIVE TO PERIODS/AREAS OF LOCALLY
HEAVY RAINFALL AND PERHAPS A ROUND OR TWO OF SEVERE WEATHER.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 749 AM EDT WED MAY 28 2014
WIDESPREAD IFR SOUTH OF I-96 EARLY THIS MORNING SHOULD IMPROVE TO
MOSTLY MVFR CONDITIONS BY MID MORNING. RAIN SHOWERS ARE EXPECTED
TO BECOME MORE NUMEROUS ACROSS THIS SAME AREA BY MID MORNING AND
CONTINUE THROUGH EARLY AFTERNOON. CONDITIONS SHOULD THEN TURN VFR
FROM NORTH TO SOUTH AFTER 18Z... WITH WIDESPREAD VFR LIKELY
TONIGHT AS DRIER AIR GRADUALLY WORKS IN.
&&
.MARINE...
ISSUED AT 330 AM EDT WED MAY 28 2014
THE MAIN ITEM OF INTEREST FOR MARINERS IS THE ONGOING POTENTIAL OF
FOG FOR THE NEARSHORE WATERS FOR TODAY. A LOOK AT WEBCAMS ALONG THE
COAST AND VISIBILITY REPORTS ALONG THE COAST INDICATE THAT FOG IS
NOT A WIDESPREAD PROBLEM THIS MORNING. THERE IS SOME FLOATING AROUND
OUT THERE...BUT NOT EVERYWHERE. WE WILL CONTINUE THE MENTION OF FOG
EARLY BEFORE MUCH DRIER AIR ADVECTS IN THIS AFTERNOON.
WINDS AND WAVES DO NOT LOOK TO BE MUCH OF AN ISSUE WITH WINDS
REMAINING AROUND OR BELOW 15 KNOTS THROUGH THE END OF THE WEEK.
&&
.HYDROLOGY...
ISSUED AT 128 PM EDT TUE MAY 27 2014
RIVER LEVELS CONTINUE TO DECLINE...WITH THE EXCEPTION OF SYCAMORE
CREEK AT HOLT. SOME RIVER LEVELS HAVE EXHIBITED SLOWER RATES OF
DECLINE FOLLOWING LAST NIGHT`S RAINFALL. RAINFALL FROM SCATTERED
SHOWERS AND STORMS THIS AFTERNOON AND EVENING MAY HAVE A SIMILAR
EFFECT. A QUARTER TO HALF INCH OF RAIN IS POSSIBLE...WITH LOCALLY
HIGHER AMOUNTS IN THUNDERSTORMS. THE THUNDERSTORMS WILL BE SLOW
MOVING...ALLOWING THE POTENTIAL FOR HEAVY RAINFALL.
RIVER ADVISORIES CONTINUE AT MAPLE RAPIDS, IONIA, AND EAGLE. ALL 3
ARE ON THE DECLINE...BUT EFFICIENT RAIN PRODUCING THUNDERSTORMS
LATER THIS AFTERNOON AND EVENING MAY DELAY THE FALL OF THOSE RIVERS
BACK BELOW BANKFULL.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...EBW
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
129 AM EDT WED MAY 28 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 409 PM EDT TUE MAY 27 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE FROM
THEN WRN PLAINS TO NW ONTARIO BETWEEN TROUGHS OFF THE PAC NW AND THE
CANADIAN MARITIMES. AT THE SFC...A RIDGE EXTENDED FROM WRN HUDSON BAY
INTO THE NRN GREAT LAKES. SOME LIGHT SHOWERS LINGERED OVER NRN WI
SUPPORTED BY A WEAK SHRTWV NORTH OF A FRONT LOW OVER SE MN AND FRONT
THROUGH SRN WI.
TONIGHT...EXPECT THE WI SHRTWV AND REMAINING MID CLOUDS INTO THE SRN
PORTION OF THE CWA TO DRIFT TO THE SE. AN AREA OF VERY DRY AIR WILL
DROP INTO THE NRN LAKES WITH PWAT VALUES FALLING TO NEAR 0.3 INCH.
FAVORABLE RADIATIONAL COOLING CONDITIONS WITH LIGHT WINDS AND MOSTLY
CLEAR SKIES WILL ALLOW TEMPS TO DROP TOWARD THE LOWER END OF
GUIDANCE.
WEDNESDAY...THE MID/UPPER LEVEL RIDGE WILL CONTINUE TO BUILD INTO
THE REGION AS SFC HIGH PRES ALSO DOMINATES. A STRENGTHENING
SUBSIDENCE INVERSION MAY LIMIT THE MIXING DEPTH...BUT WITH MOSTLY
SUNNY SKIES TEMPS SHOULD STILL CLIMB INTO THE MID AND UPPER 70S.
LAKE BREEZES WILL KEEP READINGS MAINLY IN THE UPPER 50S AND 60S NEAR
LAKE SUPERIOR. WITH THE VERY DRY 900-750 MB LAYER...EXPECT DEWPOINTS
WILL DROP TOWARD THE LOWER END OF GUIDANCE WITH RH DOWN TO NEAR 20
PERCENT OVER THE INTERIOR WEST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 325 PM EDT TUE MAY 27 2014
MUCH OF THE LONG TERM PERIOD WILL BE DRY DUE TO CANADIAN HIGH
PRESSURE OVER THE AREA THROUGH THE FIRST PART OF THE WEEKEND.
THIS HIGH PRESSURE RIDGE...WHICH IS CURRENTLY STRETCHING SOUTHEAST
OVER THE NORTHWESTERN HALF OF UPPER MICHIGAN...WILL SLOWLY SLIDE
SOUTHEAST ACROSS THE AREA THROUGH SATURDAY (AS THE PARENT HIGH MOVES
EAST FROM CENTRAL CANADA AND INTO QUEBEC). AS THIS OCCURS...THE
UPPER RIDGE AXIS OVER ONTARIO WILL AMPLIFY AND PUT THE UPPER GREAT
LAKES UNDER IT INTO SATURDAY NIGHT. WITH THE DRY AIR ASSOCIATED WITH
THE RIDGES...EXPECT A MOSTLY CLEAR SKY TO BE IN PLACE ALTHOUGH THERE
COULD BE A FEW MID-HIGH CLOUDS THAT BRUSH THE NORTHERN HALF OF THE
CWA AT TIMES. IN ADDITION...THERE ARE A COUPLE HINTS OF SOME LOWER
LEVEL MOISTURE AND WITH DIURNAL HEATING AND LAKE BREEZES...COULD SEE
A FEW DIURNAL CU. WINDS DURING THIS PERIOD WILL BE LIGHT AND EITHER
VARIABLE OR OUT OF AT NORTHERLY DIRECTION...WHICH WITH DIURNAL
HEATING AND THE COLD GREAT LAKES TEMPERATURES...EXPECT AFTERNOON
LAKE BREEZES TO BE THE NORM ON MOST DAYS. THUS...INTERIOR LOCATIONS
WILL EXPERIENCE THE WARMEST TEMPERATURES (HIGHS GENERALLY IN THE 70S
AND LOWER 80S) WHILE THE LAKESHORES WILL WARM UP IN THE MORNING AND
THEN START COOLING BY EARLY AFTERNOON. DECENT MIXING OVER THE INLAND
AREAS WILL SUPPORT LOWER RH VALUES IN THE AFTERNOONS (MID 20S TO MID
30S PERCENT)...BUT LIGHT WINDS AND A RAPIDLY OCCURRING GREEN UP WILL
LIMIT FIRE WEATHER CONCERNS.
HEADING INTO THE WEEKEND...THE GENERAL IDEA OF A COLD FRONT SLOWLY
APPROACHING THE AREA SATURDAY NIGHT AND THEN MOVING THROUGH THE
AREA OVER THE NEXT COUPLE OF DAYS IS CONSISTENT IN THE MODELS. THE
MAIN UNCERTAINTY IS THE AMOUNT OF MOISTURE ASSOCIATED WITH THE
FRONT AND EXACT TIMING. A CONSENSUS OF THE MODELS WITH THE FRONT
MOVING THROUGH DURING THE SUNDAY INTO SUNDAY NIGHT TIME FRAME SEEMS
REASONABLE AND WILL CONTINUE TO HIGHLIGHT CHANCE POPS THEN. A BRIEF
HIGH PRESSURE RIDGE MAY MOVE OVER THE AREA BEHIND THE FRONT ON
MONDAY...BUT MODELS ARE INDICATING THE UPPER RIDGE SHIFTING EAST AND
A BROAD LOW PRESSURE SYSTEM MOVING TOWARDS THE GREAT LAKES REGION
FOR TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 127 AM EDT WED MAY 28 2014
EXPECT VFR CONDITIONS TO DOMINATE THIS FCST PERIOD WITH A DRY NE
FLOW ON THE SOUTHERN FLANK OF HIGH PRESSURE BUILDING FROM NRN
ONTARIO INTO THE WESTERN GREAT LAKES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 PM EDT TUE MAY 27 2014
WITH RELATIVELY WEAK PRES GRADIENT TYPICAL OF THE WARM SEASON
DOMINATING THRU THIS FORECAST PERIOD...EXPECT WINDS MOSTLY UNDER
20KT TO PREVAIL THROUGH SAT. SOUTH WINDS MAY NEAR OR EXCEED 20 KNOTS
BY SAT NIGHT INTO SUN AHEAD OF A FRONTAL SYSTEM APPROACHING FROM THE
NW.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...TITUS
MARINE...JLB
AREA FORECAST DISCUSSION
NWS BILLINGS MT
902 AM MDT WED MAY 28 2014
.UPDATE...
NO UPDATE THIS MORNING AS THE FORECAST IS ON TRACK. STC
&&
.SHORT TERM...VALID FOR TDY AND THU...
WE ARE INCREASINGLY CONCERNED ABOUT THE POSSIBILITY OF ISOLATED TO
WIDELY SCATTERED STRONG TO SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING. COVERAGE OF STORMS WILL LIKELY BE RELATIVELY LOW...BUT WE
FEEL ANY THAT DO FORM WILL CARRY A RISK OF SEVERE WEATHER.
EARLY THIS MORNING...A SLIGHT CHANCE OF STORMS WILL CONTINUE UNTIL
ABOUT 13 UTC IN FAR SOUTHEASTERN MT AROUND BAKER...BUT CAPPING MAY
INCREASINGLY LIMIT ACTIVITY THAT FAR SOUTH BEFORE DAYBREAK. WE ARE
THEN SET UP FOR A HOT...BUT QUIET PERIOD UNTIL LATE AFTERNOON.
BY LATE THIS AFTERNOON...INTENSE HEATING WITH TEMPERATURES NEAR OR
ABOVE 90 F IN MANY PLACES WILL LIKELY WEAKEN MLCIN ENOUGH TO YIELD
HIGH-BASED CONVECTION IN SOUTH CENTRAL MT AND NORTH CENTRAL WY. WE
NOTE THAT THE 00 UTC GUIDANCE IS ON BOARD WITH WEAK /YET NOTABLE/
HEIGHT FALLS BY LATE AFTERNOON IN THOSE AREAS TOO...SO THE LARGER-
SCALE SYNOPTIC ENVIRONMENT WILL FAVOR CONVECTION. THE EXPERIMENTAL
PROBABILITY OF CONVECTIVE INITIATION GENERATED OFF THE 00 UTC NSSL
WRF-ARW IS BETWEEN 30 AND 70 PERCENT BY 23 UTC IN SOUTH CENTRAL MT
AND NORTH CENTRAL WY. MLCAPE OF 500 TO PERHAPS 1000 J/KG IS LIKELY
/DEPENDING ON HOW MUCH LOW-LEVEL MOISTURE MIXES OUT/...SO ISOLATED
TO WIDELY SCATTERED STORMS SHOULD FORM BY LATE AFTERNOON AND MAYBE
EVEN IMPACT PLACES LIKE BILLINGS WITH SOME RISK OF HAIL AND WINDS.
THAT ACTIVITY WILL THEN SPREAD NORTH AND EASTWARD INTO CENTRAL AND
POSSIBLY EASTERN MT BY EVENING...LIKELY INTENSIFYING FURTHER AS IT
ENCOUNTERS GREATER LOW-LEVEL MOISTURE WITH MLCAPE VALUES LIKELY TO
BE CLOSER TO 1000 J/KG NEAR HARLOWTON...INCREASING TO 1500 TO 2000
J/KG FROM ROUNDUP ACROSS NORTHERN ROSEBUD COUNTY AND EAST TO MILES
CITY AND BAKER. GIVEN 40-50 KT OF 0-6-KM SHEAR AND VERY STEEP MID-
LEVEL LAPSE RATES IN EXCESS OF 8 C/KM...LARGE HAIL IS POSSIBLE AND
A DEEPLY/WELL-MIXED BOUNDARY LAYER SUPPORTS DAMAGING WINDS TOO. WE
CANNOT RULE OUT A TORNADO EITHER...ESPECIALLY IF OVERNIGHT RUNS OF
THE RAP ARE CORRECT IN SHOWING A THETA-E RIDGE AXIS POINTED SOUTH-
WEST TOWARD RYEGATE...ROUNDUP AND INTO NORTHERN ROSEBUD COUNTY AS
HIGH-BASED SUPERCELLS COULD READILY INTERCEPT THAT ENVIRONMENT.
WE NEED TO STRESS ONCE MORE THAT ONLY ISOLATED TO WIDELY SCATTERED
STORMS ARE EXPECTED...AND THEY WILL ONLY COME IN ONE BATCH SO THIS
WILL NOT BE A PROLONGED EVENT. COVERAGE WILL BE LOW...BUT THERE IS
A SEVERE RISK WITH ANY DEEP MOIST CONVECTION THAT CAN INITIATE. WE
ARE NOT POSITIVE ANY STORMS WILL DEVELOP...BUT CONFIDENCE FOR SOME
ACTIVITY HAS INCREASED SINCE YESTERDAY. EVEN GUIDANCE FROM THE SPC
SSEO RUN FROM 00 UTC SUPPORTS THIS NOTION...WITH A FEW CONVECTION-
ALLOWING MODELS EVEN GENERATING NOTABLE UPDRAFT HELICITY TRACKS IN
THE NORTHERN PARTS OF OUR FORECAST AREA FROM WHEATLAND COUNTY EAST
TOWARD MUSSELSHELL...NORTHERN ROSEBUD AND CUSTER COUNTIES. ODDS OF
STORMS AND SEVERE WEATHER ARE STILL HIGHER IN NORTHERN MT...BUT WE
SAW ENOUGH EVIDENCE IN THE THREAT TO EXPLICITLY MENTION WITHIN THE
GRIDDED AND POINT AND CLICK FORECASTS IN PLACES.
BY THU...A MORE QUIET DAY IS EXPECTED AS THE SURFACE COLD FRONT IS
EXPECTED TO BE IN THE DAKOTAS BY PEAK HEATING. HOWEVER...WE ARE IN
NEED OF SOME STORM CHANCES IN FAR SOUTHEASTERN MT WHERE IT WILL BE
A CLOSE CALL WITH FRONTAL TIMING. SOUTHEASTERN MT MAY ACTUALLY GET
IN ON MORE STORMS THU NIGHT AS A SHORTWAVE HELPS LIFT THAT THERMAL
BOUNDARY BACK TO THE NORTH AND SOME TROPICAL MOISTURE PERHAPS GETS
ENTRAINED INTO THE MID- AND UPPER-LEVEL FLOW. MEANWHILE...WE STILL
HAVE SOME STORM CHANCES IN PLACE ACROSS SOUTH CENTRAL MT AND NORTH
CENTRAL WY DURING THE LATE AFTERNOON AND EVENING TOO WITH EASTERLY
WINDS AND WEAK INSTABILITY MAYBE YIELDING WEAK STORMS IN AND CLOSE
TO THE HIGHER TERRAIN. IT WILL BE COOLER THU TOO WITH HIGHS IN THE
70S F IN THE LOWER ELEVATIONS. SCHULTZ
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
THE EXTENDED FORECAST HAS FEW CHANGES IN IT. OVERALL A WET AND
STORMY PATTERN PERSISTS IN ALL THE MODELS AS HIGH PRECIPITABLE
MOISTURE LEVELS COMBINE WITH DIFFLUENT SOUTHWEST FLOW AND SEVERAL
SLOW MOVING STORM SYSTEMS. MODELS SHOW 2 TO 4 INCHES OF
PRECIPITATION OVER THE NEXT 7 DAYS WIDESPREAD ACROSS THE
AREA...WITH POTENTIALLY ANOTHER 1 TO 2 INCHES IN THE FOLLOWING 3
DAYS. SHOULD THIS OCCUR FLOODING ALREADY OCCURRING ON RIVERS AND
STREAMS WOULD BE INCREASED SIGNIFICANTLY. SO THIS IS A THREATENING
SITUATION THAT THE MODELS ARE PORTRAYING THAT WILL NEED TO BE
MONITORED CLOSELY OVER THE COMING DAYS.
FRIDAY INTO SATURDAY DIFFLUENT SOUTHWEST FLOW ALOFT WILL BRING
SEVERAL DISTURBANCES ACROSS THE FORECAST AREA. PRECIPITABLE WATER
VALUES IN THE 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL WILL ALLOW
FOR HEAVY PRECIPITATION WITH ANY STORMS THAT DO DEVELOP. SHEAR
WILL BE PROVIDED BY EAST TO NORTHEAST LOW LEVEL WINDS AS SURFACE
TROF RESIDES NEAR THE DIVIDE. CIPS ANALOGS NOT SHOWING A LOT OF
SEVERE REPORTS WITH THIS PATTERN...HOWEVER THE REPORTS THAT ARE
ASSOCIATED WITH THIS PATTERN ARE TORNADOS AND LARGE HAIL. WITH THE
SHEAR AND LOW LCL VALUES PROVIDED BY THE HIGH PWS THIS MAKES
SENSE. SO WILL HAVE TO KEEP AN EYE OUT FOR CONTINUED SEVERE STORMS
GOING INTO THE WEEKEND AS WELL.
SUNDAY AND MONDAY WILL SEE AN UPPER LOW TRANSIT OUT OF CALIFORNIA
AND INTO IDAHO. WHAT IT DOES FROM THERE DEPENDS ON THE MODEL AS
THE ECMWF DRIFTS IT EAST AND NORTHEAST...WHILE THE LATEST GFS
HOLDS IT IN PLACE OVER WESTERN MONTANA AND IDAHO INTO TUESDAY.
BOTH SOLUTIONS ARE WET FOR SOUTHERN MONTANA AND NORTHERN WYOMING
BUT THROUGH SLIGHTLY DIFFERENT PROCESSES. HAVE BUMPED
PRECIPITATION CHANCES UP TO LIKELY TO COVER THE MORE WIDESPREAD
PRECIPITATION THREAT.
TUESDAY AND WEDNESDAY ANOTHER PACIFIC STORM SYSTEM DROPS INTO THE
PACIFIC NORTHWEST AND CARVES OUT A WESTERN US TROF. ONCE AGAIN
MODELS AIM AT A POSITION OVER SOUTHEAST IDAHO FOR THIS SYSTEM TO
TAKE UP RESIDENCE WHICH PUTS IT IN A GREAT PRECIPITATION PRODUCING
LOCATION FOR OUR AREA...ESPECIALLY FROM ROUNDUP TO SHERIDAN AND
WEST. MODELS STILL BOUNCING AROUND WITH DETAILS AND WITH
INCONSISTENCY WITH THE SUNDAY MONDAY SYSTEM ELECTED TO KEEP CHANCE
POPS GOING FOR THIS TIME FRAME...BUT THE POTENTIAL FOR MORE
WIDESPREAD MODERATE TO HEAVY RAIN EXISTS. CHAMBERS
&&
.AVIATION...
AN AREA OF UPSLOPE INDUCED STRATUS CLOUDS WILL CONTINUE TO
GENERATE MVFR CIGS IN THE BEARTOOTH-ABSAROKA FOOTHILLS REGION
THROUGH 17Z BEFORE THIS LAYER DISSIPATES.
VFR CONDITIONS WILL PREVAIL THIS AFTERNOON AND EVENING. SURFACE
WINDS WILL INCREASE WITH GUSTS 20 TO 35 KTS COMMON THIS
AFTERNOON. ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED TO
DEVELOP OVER HIGHER TERRAIN TO THE SOUTH AND MOVE THROUGH THE AREA
THIS AFTERNOON AND EARLY EVENING. A FEW SEVERE STORMS ARE POSSIBLE
WITH LARGE HAIL AND STRONG WINDS. LOCAL MVFR/IFR CONDITIONS IN
HEAVY RAIN CAN BE EXPECTED NEAR STORMS. STC
&&
.PRELIMINARY POINT TEMP/POPS...
TDY THU FRI SAT SUN MON TUE
-------------------------------------------------------
BIL 089 057/073 052/076 054/076 056/072 054/069 051/073
3/T 22/T 24/T 54/T 46/T 66/T 64/T
LVM 084 047/072 043/074 047/077 048/072 048/067 045/072
2/T 22/T 23/T 35/T 56/T 66/T 64/T
HDN 092 059/076 053/079 054/080 055/076 053/072 051/075
3/T 21/B 24/T 54/T 46/T 66/T 64/T
MLS 094 062/077 055/079 057/079 056/074 054/072 052/073
2/T 31/B 23/T 43/T 34/T 66/T 64/T
4BQ 094 063/078 055/077 056/079 056/077 055/075 052/074
1/U 21/B 45/T 54/T 44/T 66/T 65/T
BHK 089 062/078 054/076 054/076 052/072 051/070 050/070
1/N 21/B 44/T 64/T 44/T 66/T 64/T
SHR 091 056/075 050/075 049/078 049/075 049/072 046/073
2/T 23/T 35/T 55/T 56/T 66/T 64/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
644 AM MDT WED MAY 28 2014
.UPDATE...
WE MADE A MINOR UPDATE TO THE FORECAST TO REMOVE THE SLIGHT CHANCE
OF THUNDERSTORMS WE HAD IN BAKER UNTIL 15 UTC SINCE ALL THE STORMS
ARE NOW NORTH AND EAST OF THE AREA AND MID-LEVEL CAPPING HAS TAKEN
HOLD OF SOUTHEASTERN MT. WE ALSO INCLUDED MOSTLY CLOUDY SKIES OVER
PARTS OF SOUTH CENTRAL MT UNTIL 15 UTC WHERE STRATUS HAS DEVELOPED
EARLY THIS MORNING FROM LIVINGSTON AND HARLOWTON EASTWARD TO NEAR
RYEGATE AND EVEN AROUND BILLINGS. THOSE CLOUDS SHOULD QUICKLY LIFT
BY MID MORNING. SCHULTZ
&&
.SHORT TERM...VALID FOR TDY AND THU...
WE ARE INCREASINGLY CONCERNED ABOUT THE POSSIBILITY OF ISOLATED TO
WIDELY SCATTERED STRONG TO SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING. COVERAGE OF STORMS WILL LIKELY BE RELATIVELY LOW...BUT WE
FEEL ANY THAT DO FORM WILL CARRY A RISK OF SEVERE WEATHER.
EARLY THIS MORNING...A SLIGHT CHANCE OF STORMS WILL CONTINUE UNTIL
ABOUT 13 UTC IN FAR SOUTHEASTERN MT AROUND BAKER...BUT CAPPING MAY
INCREASINGLY LIMIT ACTIVITY THAT FAR SOUTH BEFORE DAYBREAK. WE ARE
THEN SET UP FOR A HOT...BUT QUIET PERIOD UNTIL LATE AFTERNOON.
BY LATE THIS AFTERNOON...INTENSE HEATING WITH TEMPERATURES NEAR OR
ABOVE 90 F IN MANY PLACES WILL LIKELY WEAKEN MLCIN ENOUGH TO YIELD
HIGH-BASED CONVECTION IN SOUTH CENTRAL MT AND NORTH CENTRAL WY. WE
NOTE THAT THE 00 UTC GUIDANCE IS ON BOARD WITH WEAK /YET NOTABLE/
HEIGHT FALLS BY LATE AFTERNOON IN THOSE AREAS TOO...SO THE LARGER-
SCALE SYNOPTIC ENVIRONMENT WILL FAVOR CONVECTION. THE EXPERIMENTAL
PROBABILITY OF CONVECTIVE INITIATION GENERATED OFF THE 00 UTC NSSL
WRF-ARW IS BETWEEN 30 AND 70 PERCENT BY 23 UTC IN SOUTH CENTRAL MT
AND NORTH CENTRAL WY. MLCAPE OF 500 TO PERHAPS 1000 J/KG IS LIKELY
/DEPENDING ON HOW MUCH LOW-LEVEL MOISTURE MIXES OUT/...SO ISOLATED
TO WIDELY SCATTERED STORMS SHOULD FORM BY LATE AFTERNOON AND MAYBE
EVEN IMPACT PLACES LIKE BILLINGS WITH SOME RISK OF HAIL AND WINDS.
THAT ACTIVITY WILL THEN SPREAD NORTH AND EASTWARD INTO CENTRAL AND
POSSIBLY EASTERN MT BY EVENING...LIKELY INTENSIFYING FURTHER AS IT
ENCOUNTERS GREATER LOW-LEVEL MOISTURE WITH MLCAPE VALUES LIKELY TO
BE CLOSER TO 1000 J/KG NEAR HARLOWTON...INCREASING TO 1500 TO 2000
J/KG FROM ROUNDUP ACROSS NORTHERN ROSEBUD COUNTY AND EAST TO MILES
CITY AND BAKER. GIVEN 40-50 KT OF 0-6-KM SHEAR AND VERY STEEP MID-
LEVEL LAPSE RATES IN EXCESS OF 8 C/KM...LARGE HAIL IS POSSIBLE AND
A DEEPLY/WELL-MIXED BOUNDARY LAYER SUPPORTS DAMAGING WINDS TOO. WE
CANNOT RULE OUT A TORNADO EITHER...ESPECIALLY IF OVERNIGHT RUNS OF
THE RAP ARE CORRECT IN SHOWING A THETA-E RIDGE AXIS POINTED SOUTH-
WEST TOWARD RYEGATE...ROUNDUP AND INTO NORTHERN ROSEBUD COUNTY AS
HIGH-BASED SUPERCELLS COULD READILY INTERCEPT THAT ENVIRONMENT.
WE NEED TO STRESS ONCE MORE THAT ONLY ISOLATED TO WIDELY SCATTERED
STORMS ARE EXPECTED...AND THEY WILL ONLY COME IN ONE BATCH SO THIS
WILL NOT BE A PROLONGED EVENT. COVERAGE WILL BE LOW...BUT THERE IS
A SEVERE RISK WITH ANY DEEP MOIST CONVECTION THAT CAN INITIATE. WE
ARE NOT POSITIVE ANY STORMS WILL DEVELOP...BUT CONFIDENCE FOR SOME
ACTIVITY HAS INCREASED SINCE YESTERDAY. EVEN GUIDANCE FROM THE SPC
SSEO RUN FROM 00 UTC SUPPORTS THIS NOTION...WITH A FEW CONVECTION-
ALLOWING MODELS EVEN GENERATING NOTABLE UPDRAFT HELICITY TRACKS IN
THE NORTHERN PARTS OF OUR FORECAST AREA FROM WHEATLAND COUNTY EAST
TOWARD MUSSELSHELL...NORTHERN ROSEBUD AND CUSTER COUNTIES. ODDS OF
STORMS AND SEVERE WEATHER ARE STILL HIGHER IN NORTHERN MT...BUT WE
SAW ENOUGH EVIDENCE IN THE THREAT TO EXPLICITLY MENTION WITHIN THE
GRIDDED AND POINT AND CLICK FORECASTS IN PLACES.
BY THU...A MORE QUIET DAY IS EXPECTED AS THE SURFACE COLD FRONT IS
EXPECTED TO BE IN THE DAKOTAS BY PEAK HEATING. HOWEVER...WE ARE IN
NEED OF SOME STORM CHANCES IN FAR SOUTHEASTERN MT WHERE IT WILL BE
A CLOSE CALL WITH FRONTAL TIMING. SOUTHEASTERN MT MAY ACTUALLY GET
IN ON MORE STORMS THU NIGHT AS A SHORTWAVE HELPS LIFT THAT THERMAL
BOUNDARY BACK TO THE NORTH AND SOME TROPICAL MOISTURE PERHAPS GETS
ENTRAINED INTO THE MID- AND UPPER-LEVEL FLOW. MEANWHILE...WE STILL
HAVE SOME STORM CHANCES IN PLACE ACROSS SOUTH CENTRAL MT AND NORTH
CENTRAL WY DURING THE LATE AFTERNOON AND EVENING TOO WITH EASTERLY
WINDS AND WEAK INSTABILITY MAYBE YIELDING WEAK STORMS IN AND CLOSE
TO THE HIGHER TERRAIN. IT WILL BE COOLER THU TOO WITH HIGHS IN THE
70S F IN THE LOWER ELEVATIONS. SCHULTZ
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
THE EXTENDED FORECAST HAS FEW CHANGES IN IT. OVERALL A WET AND
STORMY PATTERN PERSISTS IN ALL THE MODELS AS HIGH PRECIPITABLE
MOISTURE LEVELS COMBINE WITH DIFFLUENT SOUTHWEST FLOW AND SEVERAL
SLOW MOVING STORM SYSTEMS. MODELS SHOW 2 TO 4 INCHES OF
PRECIPITATION OVER THE NEXT 7 DAYS WIDESPREAD ACROSS THE
AREA...WITH POTENTIALLY ANOTHER 1 TO 2 INCHES IN THE FOLLOWING 3
DAYS. SHOULD THIS OCCUR FLOODING ALREADY OCCURRING ON RIVERS AND
STREAMS WOULD BE INCREASED SIGNIFICANTLY. SO THIS IS A THREATENING
SITUATION THAT THE MODELS ARE PORTRAYING THAT WILL NEED TO BE
MONITORED CLOSELY OVER THE COMING DAYS.
FRIDAY INTO SATURDAY DIFFLUENT SOUTHWEST FLOW ALOFT WILL BRING
SEVERAL DISTURBANCES ACROSS THE FORECAST AREA. PRECIPITABLE WATER
VALUES IN THE 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL WILL ALLOW
FOR HEAVY PRECIPITATION WITH ANY STORMS THAT DO DEVELOP. SHEAR
WILL BE PROVIDED BY EAST TO NORTHEAST LOW LEVEL WINDS AS SURFACE
TROF RESIDES NEAR THE DIVIDE. CIPS ANALOGS NOT SHOWING A LOT OF
SEVERE REPORTS WITH THIS PATTERN...HOWEVER THE REPORTS THAT ARE
ASSOCIATED WITH THIS PATTERN ARE TORNADOS AND LARGE HAIL. WITH THE
SHEAR AND LOW LCL VALUES PROVIDED BY THE HIGH PWS THIS MAKES
SENSE. SO WILL HAVE TO KEEP AN EYE OUT FOR CONTINUED SEVERE STORMS
GOING INTO THE WEEKEND AS WELL.
SUNDAY AND MONDAY WILL SEE AN UPPER LOW TRANSIT OUT OF CALIFORNIA
AND INTO IDAHO. WHAT IT DOES FROM THERE DEPENDS ON THE MODEL AS
THE ECMWF DRIFTS IT EAST AND NORTHEAST...WHILE THE LATEST GFS
HOLDS IT IN PLACE OVER WESTERN MONTANA AND IDAHO INTO TUESDAY.
BOTH SOLUTIONS ARE WET FOR SOUTHERN MONTANA AND NORTHERN WYOMING
BUT THROUGH SLIGHTLY DIFFERENT PROCESSES. HAVE BUMPED
PRECIPITATION CHANCES UP TO LIKELY TO COVER THE MORE WIDESPREAD
PRECIPITATION THREAT.
TUESDAY AND WEDNESDAY ANOTHER PACIFIC STORM SYSTEM DROPS INTO THE
PACIFIC NORTHWEST AND CARVES OUT A WESTERN US TROF. ONCE AGAIN
MODELS AIM AT A POSITION OVER SOUTHEAST IDAHO FOR THIS SYSTEM TO
TAKE UP RESIDENCE WHICH PUTS IT IN A GREAT PRECIPITATION PRODUCING
LOCATION FOR OUR AREA...ESPECIALLY FROM ROUNDUP TO SHERIDAN AND
WEST. MODELS STILL BOUNCING AROUND WITH DETAILS AND WITH
INCONSISTENCY WITH THE SUNDAY MONDAY SYSTEM ELECTED TO KEEP CHANCE
POPS GOING FOR THIS TIME FRAME...BUT THE POTENTIAL FOR MORE
WIDESPREAD MODERATE TO HEAVY RAIN EXISTS. CHAMBERS
&&
.AVIATION...
AN AREA OF UPSLOPE INDUCED STRATUS CLOUDS HAS DEVELOPED FROM
BILLINGS WEST TO LIVINGSTON. OCCASIONAL MVFR CEILINGS CAN BE
EXPECTED THROUGH 16Z BEFORE THIS LAYER DISSIPATES.
VFR CONDITIONS WILL PREVAIL THIS AFTERNOON AND EVENING. SURFACE
WINDS WILL INCREASE WITH GUSTS 20 TO 35KTS COMMON THIS AFTERNOON.
ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER
HIGHER TERRAIN TO THE SOUTH AND MOVE THROUGH THE AREA THIS
AFTERNOON AND EARLY EVENING. A FEW SEVERE STORMS ARE POSSIBLE WITH
LARGE HAIL AND STRONG WINDS. LOCAL IFR CONDITIONS IN HEAVY RAIN
CAN BE EXPECTED NEAR STORMS. CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
TDY THU FRI SAT SUN MON TUE
-------------------------------------------------------
BIL 089 057/073 052/076 054/076 056/072 054/069 051/073
3/T 22/T 24/T 54/T 46/T 66/T 64/T
LVM 084 047/072 043/074 047/077 048/072 048/067 045/072
2/T 22/T 23/T 35/T 56/T 66/T 64/T
HDN 092 059/076 053/079 054/080 055/076 053/072 051/075
3/T 21/B 24/T 54/T 46/T 66/T 64/T
MLS 094 062/077 055/079 057/079 056/074 054/072 052/073
2/T 31/B 23/T 43/T 34/T 66/T 64/T
4BQ 094 063/078 055/077 056/079 056/077 055/075 052/074
1/U 21/B 45/T 54/T 44/T 66/T 65/T
BHK 089 062/078 054/076 054/076 052/072 051/070 050/070
1/N 21/B 44/T 64/T 44/T 66/T 64/T
SHR 091 056/075 050/075 049/078 049/075 049/072 046/073
2/T 23/T 35/T 55/T 56/T 66/T 64/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
528 AM MDT WED MAY 28 2014
.SHORT TERM...VALID FOR TDY AND THU...
WE ARE INCREASINGLY CONCERNED ABOUT THE POSSIBILITY OF ISOLATED TO
WIDELY SCATTERED STRONG TO SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING. COVERAGE OF STORMS WILL LIKELY BE RELATIVELY LOW...BUT WE
FEEL ANY THAT DO FORM WILL CARRY A RISK OF SEVERE WEATHER.
EARLY THIS MORNING...A SLIGHT CHANCE OF STORMS WILL CONTINUE UNTIL
ABOUT 13 UTC IN FAR SOUTHEASTERN MT AROUND BAKER...BUT CAPPING MAY
INCREASINGLY LIMIT ACTIVITY THAT FAR SOUTH BEFORE DAYBREAK. WE ARE
THEN SET UP FOR A HOT...BUT QUIET PERIOD UNTIL LATE AFTERNOON.
BY LATE THIS AFTERNOON...INTENSE HEATING WITH TEMPERATURES NEAR OR
ABOVE 90 F IN MANY PLACES WILL LIKELY WEAKEN MLCIN ENOUGH TO YIELD
HIGH-BASED CONVECTION IN SOUTH CENTRAL MT AND NORTH CENTRAL WY. WE
NOTE THAT THE 00 UTC GUIDANCE IS ON BOARD WITH WEAK /YET NOTABLE/
HEIGHT FALLS BY LATE AFTERNOON IN THOSE AREAS TOO...SO THE LARGER-
SCALE SYNOPTIC ENVIRONMENT WILL FAVOR CONVECTION. THE EXPERIMENTAL
PROBABILITY OF CONVECTIVE INITIATION GENERATED OFF THE 00 UTC NSSL
WRF-ARW IS BETWEEN 30 AND 70 PERCENT BY 23 UTC IN SOUTH CENTRAL MT
AND NORTH CENTRAL WY. MLCAPE OF 500 TO PERHAPS 1000 J/KG IS LIKELY
/DEPENDING ON HOW MUCH LOW-LEVEL MOISTURE MIXES OUT/...SO ISOLATED
TO WIDELY SCATTERED STORMS SHOULD FORM BY LATE AFTERNOON AND MAYBE
EVEN IMPACT PLACES LIKE BILLINGS WITH SOME RISK OF HAIL AND WINDS.
THAT ACTIVITY WILL THEN SPREAD NORTH AND EASTWARD INTO CENTRAL AND
POSSIBLY EASTERN MT BY EVENING...LIKELY INTENSIFYING FURTHER AS IT
ENCOUNTERS GREATER LOW-LEVEL MOISTURE WITH MLCAPE VALUES LIKELY TO
BE CLOSER TO 1000 J/KG NEAR HARLOWTON...INCREASING TO 1500 TO 2000
J/KG FROM ROUNDUP ACROSS NORTHERN ROSEBUD COUNTY AND EAST TO MILES
CITY AND BAKER. GIVEN 40-50 KT OF 0-6-KM SHEAR AND VERY STEEP MID-
LEVEL LAPSE RATES IN EXCESS OF 8 C/KM...LARGE HAIL IS POSSIBLE AND
A DEEPLY/WELL-MIXED BOUNDARY LAYER SUPPORTS DAMAGING WINDS TOO. WE
CANNOT RULE OUT A TORNADO EITHER...ESPECIALLY IF OVERNIGHT RUNS OF
THE RAP ARE CORRECT IN SHOWING A THETA-E RIDGE AXIS POINTED SOUTH-
WEST TOWARD RYEGATE...ROUNDUP AND INTO NORTHERN ROSEBUD COUNTY AS
HIGH-BASED SUPERCELLS COULD READILY INTERCEPT THAT ENVIRONMENT.
WE NEED TO STRESS ONCE MORE THAT ONLY ISOLATED TO WIDELY SCATTERED
STORMS ARE EXPECTED...AND THEY WILL ONLY COME IN ONE BATCH SO THIS
WILL NOT BE A PROLONGED EVENT. COVERAGE WILL BE LOW...BUT THERE IS
A SEVERE RISK WITH ANY DEEP MOIST CONVECTION THAT CAN INITIATE. WE
ARE NOT POSITIVE ANY STORMS WILL DEVELOP...BUT CONFIDENCE FOR SOME
ACTIVITY HAS INCREASED SINCE YESTERDAY. EVEN GUIDANCE FROM THE SPC
SSEO RUN FROM 00 UTC SUPPORTS THIS NOTION...WITH A FEW CONVECTION-
ALLOWING MODELS EVEN GENERATING NOTABLE UPDRAFT HELICITY TRACKS IN
THE NORTHERN PARTS OF OUR FORECAST AREA FROM WHEATLAND COUNTY EAST
TOWARD MUSSELSHELL...NORTHERN ROSEBUD AND CUSTER COUNTIES. ODDS OF
STORMS AND SEVERE WEATHER ARE STILL HIGHER IN NORTHERN MT...BUT WE
SAW ENOUGH EVIDENCE IN THE THREAT TO EXPLICITLY MENTION WITHIN THE
GRIDDED AND POINT AND CLICK FORECASTS IN PLACES.
BY THU...A MORE QUIET DAY IS EXPECTED AS THE SURFACE COLD FRONT IS
EXPECTED TO BE IN THE DAKOTAS BY PEAK HEATING. HOWEVER...WE ARE IN
NEED OF SOME STORM CHANCES IN FAR SOUTHEASTERN MT WHERE IT WILL BE
A CLOSE CALL WITH FRONTAL TIMING. SOUTHEASTERN MT MAY ACTUALLY GET
IN ON MORE STORMS THU NIGHT AS A SHORTWAVE HELPS LIFT THAT THERMAL
BOUNDARY BACK TO THE NORTH AND SOME TROPICAL MOISTURE PERHAPS GETS
ENTRAINED INTO THE MID- AND UPPER-LEVEL FLOW. MEANWHILE...WE STILL
HAVE SOME STORM CHANCES IN PLACE ACROSS SOUTH CENTRAL MT AND NORTH
CENTRAL WY DURING THE LATE AFTERNOON AND EVENING TOO WITH EASTERLY
WINDS AND WEAK INSTABILITY MAYBE YIELDING WEAK STORMS IN AND CLOSE
TO THE HIGHER TERRAIN. IT WILL BE COOLER THU TOO WITH HIGHS IN THE
70S F IN THE LOWER ELEVATIONS. SCHULTZ
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
THE EXTENDED FORECAST HAS FEW CHANGES IN IT. OVERALL A WET AND
STORMY PATTERN PERSISTS IN ALL THE MODELS AS HIGH PRECIPITABLE
MOISTURE LEVELS COMBINE WITH DIFFLUENT SOUTHWEST FLOW AND SEVERAL
SLOW MOVING STORM SYSTEMS. MODELS SHOW 2 TO 4 INCHES OF
PRECIPITATION OVER THE NEXT 7 DAYS WIDESPREAD ACROSS THE
AREA...WITH POTENTIALLY ANOTHER 1 TO 2 INCHES IN THE FOLLOWING 3
DAYS. SHOULD THIS OCCUR FLOODING ALREADY OCCURRING ON RIVERS AND
STREAMS WOULD BE INCREASED SIGNIFICANTLY. SO THIS IS A THREATENING
SITUATION THAT THE MODELS ARE PORTRAYING THAT WILL NEED TO BE
MONITORED CLOSELY OVER THE COMING DAYS.
FRIDAY INTO SATURDAY DIFFLUENT SOUTHWEST FLOW ALOFT WILL BRING
SEVERAL DISTURBANCES ACROSS THE FORECAST AREA. PRECIPITABLE WATER
VALUES IN THE 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL WILL ALLOW
FOR HEAVY PRECIPITATION WITH ANY STORMS THAT DO DEVELOP. SHEAR
WILL BE PROVIDED BY EAST TO NORTHEAST LOW LEVEL WINDS AS SURFACE
TROF RESIDES NEAR THE DIVIDE. CIPS ANALOGS NOT SHOWING A LOT OF
SEVERE REPORTS WITH THIS PATTERN...HOWEVER THE REPORTS THAT ARE
ASSOCIATED WITH THIS PATTERN ARE TORNADOS AND LARGE HAIL. WITH THE
SHEAR AND LOW LCL VALUES PROVIDED BY THE HIGH PWS THIS MAKES
SENSE. SO WILL HAVE TO KEEP AN EYE OUT FOR CONTINUED SEVERE STORMS
GOING INTO THE WEEKEND AS WELL.
SUNDAY AND MONDAY WILL SEE AN UPPER LOW TRANSIT OUT OF CALIFORNIA
AND INTO IDAHO. WHAT IT DOES FROM THERE DEPENDS ON THE MODEL AS
THE ECMWF DRIFTS IT EAST AND NORTHEAST...WHILE THE LATEST GFS
HOLDS IT IN PLACE OVER WESTERN MONTANA AND IDAHO INTO TUESDAY.
BOTH SOLUTIONS ARE WET FOR SOUTHERN MONTANA AND NORTHERN WYOMING
BUT THROUGH SLIGHTLY DIFFERENT PROCESSES. HAVE BUMPED
PRECIPITATION CHANCES UP TO LIKELY TO COVER THE MORE WIDESPREAD
PRECIPITATION THREAT.
TUESDAY AND WEDNESDAY ANOTHER PACIFIC STORM SYSTEM DROPS INTO THE
PACIFIC NORTHWEST AND CARVES OUT A WESTERN US TROF. ONCE AGAIN
MODELS AIM AT A POSITION OVER SOUTHEAST IDAHO FOR THIS SYSTEM TO
TAKE UP RESIDENCE WHICH PUTS IT IN A GREAT PRECIPITATION PRODUCING
LOCATION FOR OUR AREA...ESPECIALLY FROM ROUNDUP TO SHERIDAN AND
WEST. MODELS STILL BOUNCING AROUND WITH DETAILS AND WITH
INCONSISTENCY WITH THE SUNDAY MONDAY SYSTEM ELECTED TO KEEP CHANCE
POPS GOING FOR THIS TIME FRAME...BUT THE POTENTIAL FOR MORE
WIDESPREAD MODERATE TO HEAVY RAIN EXISTS. CHAMBERS
&&
.AVIATION...
AN AREA OF UPSLOPE INDUCED STRATUS CLOUDS HAS DEVELOPED FROM
BILLINGS WEST TO LIVINGSTON. OCCASIONAL MVFR CEILINGS CAN BE
EXPECTED THROUGH 16Z BEFORE THIS LAYER DISSIPATES.
VFR CONDITIONS WILL PREVAIL THIS AFTERNOON AND EVENING. SURFACE
WINDS WILL INCREASE WITH GUSTS 20 TO 35KTS COMMON THIS AFTERNOON.
ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER
HIGHER TERRAIN TO THE SOUTH AND MOVE THROUGH THE AREA THIS
AFTERNOON AND EARLY EVENING. A FEW SEVERE STORMS ARE POSSIBLE WITH
LARGE HAIL AND STRONG WINDS. LOCAL IFR CONDITIONS IN HEAVY RAIN
CAN BE EXPECTED NEAR STORMS. CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
TDY THU FRI SAT SUN MON TUE
-------------------------------------------------------
BIL 089 057/073 052/076 054/076 056/072 054/069 051/073
3/T 22/T 24/T 54/T 46/T 66/T 64/T
LVM 084 047/072 043/074 047/077 048/072 048/067 045/072
2/T 22/T 23/T 35/T 56/T 66/T 64/T
HDN 092 059/076 053/079 054/080 055/076 053/072 051/075
3/T 21/B 24/T 54/T 46/T 66/T 64/T
MLS 094 062/077 055/079 057/079 056/074 054/072 052/073
2/T 31/B 23/T 43/T 34/T 66/T 64/T
4BQ 094 063/078 055/077 056/079 056/077 055/075 052/074
1/U 21/B 45/T 54/T 44/T 66/T 65/T
BHK 089 062/078 054/076 054/076 052/072 051/070 050/070
2/T 21/B 44/T 64/T 44/T 66/T 64/T
SHR 091 056/075 050/075 049/078 049/075 049/072 046/073
2/T 23/T 35/T 55/T 56/T 66/T 64/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
349 AM MDT WED MAY 28 2014
.SHORT TERM...VALID FOR TDY AND THU...
WE ARE INCREASINGLY CONCERNED ABOUT THE POSSIBILITY OF ISOLATED TO
WIDELY SCATTERED STRONG TO SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING. COVERAGE OF STORMS WILL LIKELY BE RELATIVELY LOW...BUT WE
FEEL ANY THAT DO FORM WILL CARRY A RISK OF SEVERE WEATHER.
EARLY THIS MORNING...A SLIGHT CHANCE OF STORMS WILL CONTINUE UNTIL
ABOUT 13 UTC IN FAR SOUTHEASTERN MT AROUND BAKER...BUT CAPPING MAY
INCREASINGLY LIMIT ACTIVITY THAT FAR SOUTH BEFORE DAYBREAK. WE ARE
THEN SET UP FOR A HOT...BUT QUIET PERIOD UNTIL LATE AFTERNOON.
BY LATE THIS AFTERNOON...INTENSE HEATING WITH TEMPERATURES NEAR OR
ABOVE 90 F IN MANY PLACES WILL LIKELY WEAKEN MLCIN ENOUGH TO YIELD
HIGH-BASED CONVECTION IN SOUTH CENTRAL MT AND NORTH CENTRAL WY. WE
NOTE THAT THE 00 UTC GUIDANCE IS ON BOARD WITH WEAK /YET NOTABLE/
HEIGHT FALLS BY LATE AFTERNOON IN THOSE AREAS TOO...SO THE LARGER-
SCALE SYNOPTIC ENVIRONMENT WILL FAVOR CONVECTION. THE EXPERIMENTAL
PROBABILITY OF CONVECTIVE INITIATION GENERATED OFF THE 00 UTC NSSL
WRF-ARW IS BETWEEN 30 AND 70 PERCENT BY 23 UTC IN SOUTH CENTRAL MT
AND NORTH CENTRAL WY. MLCAPE OF 500 TO PERHAPS 1000 J/KG IS LIKELY
/DEPENDING ON HOW MUCH LOW-LEVEL MOISTURE MIXES OUT/...SO ISOLATED
TO WIDELY SCATTERED STORMS SHOULD FORM BY LATE AFTERNOON AND MAYBE
EVEN IMPACT PLACES LIKE BILLINGS WITH SOME RISK OF HAIL AND WINDS.
THAT ACTIVITY WILL THEN SPREAD NORTH AND EASTWARD INTO CENTRAL AND
POSSIBLY EASTERN MT BY EVENING...LIKELY INTENSIFYING FURTHER AS IT
ENCOUNTERS GREATER LOW-LEVEL MOISTURE WITH MLCAPE VALUES LIKELY TO
BE CLOSER TO 1000 J/KG NEAR HARLOWTON...INCREASING TO 1500 TO 2000
J/KG FROM ROUNDUP ACROSS NORTHERN ROSEBUD COUNTY AND EAST TO MILES
CITY AND BAKER. GIVEN 40-50 KT OF 0-6-KM SHEAR AND VERY STEEP MID-
LEVEL LAPSE RATES IN EXCESS OF 8 C/KM...LARGE HAIL IS POSSIBLE AND
A DEEPLY/WELL-MIXED BOUNDARY LAYER SUPPORTS DAMAGING WINDS TOO. WE
CANNOT RULE OUT A TORNADO EITHER...ESPECIALLY IF OVERNIGHT RUNS OF
THE RAP ARE CORRECT IN SHOWING A THETA-E RIDGE AXIS POINTED SOUTH-
WEST TOWARD RYEGATE...ROUNDUP AND INTO NORTHERN ROSEBUD COUNTY AS
HIGH-BASED SUPERCELLS COULD READILY INTERCEPT THAT ENVIRONMENT.
WE NEED TO STRESS ONCE MORE THAT ONLY ISOLATED TO WIDELY SCATTERED
STORMS ARE EXPECTED...AND THEY WILL ONLY COME IN ONE BATCH SO THIS
WILL NOT BE A PROLONGED EVENT. COVERAGE WILL BE LOW...BUT THERE IS
A SEVERE RISK WITH ANY DEEP MOIST CONVECTION THAT CAN INITIATE. WE
ARE NOT POSITIVE ANY STORMS WILL DEVELOP...BUT CONFIDENCE FOR SOME
ACTIVITY HAS INCREASED SINCE YESTERDAY. EVEN GUIDANCE FROM THE SPC
SSEO RUN FROM 00 UTC SUPPORTS THIS NOTION...WITH A FEW CONVECTION-
ALLOWING MODELS EVEN GENERATING NOTABLE UPDRAFT HELICITY TRACKS IN
THE NORTHERN PARTS OF OUR FORECAST AREA FROM WHEATLAND COUNTY EAST
TOWARD MUSSELSHELL...NORTHERN ROSEBUD AND CUSTER COUNTIES. ODDS OF
STORMS AND SEVERE WEATHER ARE STILL HIGHER IN NORTHERN MT...BUT WE
SAW ENOUGH EVIDENCE IN THE THREAT TO EXPLICITLY MENTION WITHIN THE
GRIDDED AND POINT AND CLICK FORECASTS IN PLACES.
BY THU...A MORE QUIET DAY IS EXPECTED AS THE SURFACE COLD FRONT IS
EXPECTED TO BE IN THE DAKOTAS BY PEAK HEATING. HOWEVER...WE ARE IN
NEED OF SOME STORM CHANCES IN FAR SOUTHEASTERN MT WHERE IT WILL BE
A CLOSE CALL WITH FRONTAL TIMING. SOUTHEASTERN MT MAY ACTUALLY GET
IN ON MORE STORMS THU NIGHT AS A SHORTWAVE HELPS LIFT THAT THERMAL
BOUNDARY BACK TO THE NORTH AND SOME TROPICAL MOISTURE PERHAPS GETS
ENTRAINED INTO THE MID- AND UPPER-LEVEL FLOW. MEANWHILE...WE STILL
HAVE SOME STORM CHANCES IN PLACE ACROSS SOUTH CENTRAL MT AND NORTH
CENTRAL WY DURING THE LATE AFTERNOON AND EVENING TOO WITH EASTERLY
WINDS AND WEAK INSTABILITY MAYBE YIELDING WEAK STORMS IN AND CLOSE
TO THE HIGHER TERRAIN. IT WILL BE COOLER THU TOO WITH HIGHS IN THE
70S F IN THE LOWER ELEVATIONS. SCHULTZ
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
THE EXTENDED FORECAST HAS FEW CHANGES IN IT. OVERALL A WET AND
STORMY PATTERN PERSISTS IN ALL THE MODELS AS HIGH PRECIPITABLE
MOISTURE LEVELS COMBINE WITH DIFFLUENT SOUTHWEST FLOW AND SEVERAL
SLOW MOVING STORM SYSTEMS. MODELS SHOW 2 TO 4 INCHES OF
PRECIPITATION OVER THE NEXT 7 DAYS WIDESPREAD ACROSS THE
AREA...WITH POTENTIALLY ANOTHER 1 TO 2 INCHES IN THE FOLLOWING 3
DAYS. SHOULD THIS OCCUR FLOODING ALREADY OCCURRING ON RIVERS AND
STREAMS WOULD BE INCREASED SIGNIFICANTLY. SO THIS IS A THREATENING
SITUATION THAT THE MODELS ARE PORTRAYING THAT WILL NEED TO BE
MONITORED CLOSELY OVER THE COMING DAYS.
FRIDAY INTO SATURDAY DIFFLUENT SOUTHWEST FLOW ALOFT WILL BRING
SEVERAL DISTURBANCES ACROSS THE FORECAST AREA. PRECIPITABLE WATER
VALUES IN THE 2 TO 3 STANDARD DEVIATIONS ABOVE NORMAL WILL ALLOW
FOR HEAVY PRECIPITATION WITH ANY STORMS THAT DO DEVELOP. SHEAR
WILL BE PROVIDED BY EAST TO NORTHEAST LOW LEVEL WINDS AS SURFACE
TROF RESIDES NEAR THE DIVIDE. CIPS ANALOGS NOT SHOWING A LOT OF
SEVERE REPORTS WITH THIS PATTERN...HOWEVER THE REPORTS THAT ARE
ASSOCIATED WITH THIS PATTERN ARE TORNADOS AND LARGE HAIL. WITH THE
SHEAR AND LOW LCL VALUES PROVIDED BY THE HIGH PWS THIS MAKES
SENSE. SO WILL HAVE TO KEEP AN EYE OUT FOR CONTINUED SEVERE STORMS
GOING INTO THE WEEKEND AS WELL.
SUNDAY AND MONDAY WILL SEE AN UPPER LOW TRANSIT OUT OF CALIFORNIA
AND INTO IDAHO. WHAT IT DOES FROM THERE DEPENDS ON THE MODEL AS
THE ECMWF DRIFTS IT EAST AND NORTHEAST...WHILE THE LATEST GFS
HOLDS IT IN PLACE OVER WESTERN MONTANA AND IDAHO INTO TUESDAY.
BOTH SOLUTIONS ARE WET FOR SOUTHERN MONTANA AND NORTHERN WYOMING
BUT THROUGH SLIGHTLY DIFFERENT PROCESSES. HAVE BUMPED
PRECIPITATION CHANCES UP TO LIKELY TO COVER THE MORE WIDESPREAD
PRECIPITATION THREAT.
TUESDAY AND WEDNESDAY ANOTHER PACIFIC STORM SYSTEM DROPS INTO THE
PACIFIC NORTHWEST AND CARVES OUT A WESTERN US TROF. ONCE AGAIN
MODELS AIM AT A POSITION OVER SOUTHEAST IDAHO FOR THIS SYSTEM TO
TAKE UP RESIDENCE WHICH PUTS IT IN A GREAT PRECIPITATION PRODUCING
LOCATION FOR OUR AREA...ESPECIALLY FROM ROUNDUP TO SHERIDAN AND
WEST. MODELS STILL BOUNCING AROUND WITH DETAILS AND WITH
INCONSISTENCY WITH THE SUNDAY MONDAY SYSTEM ELECTED TO KEEP CHANCE
POPS GOING FOR THIS TIME FRAME...BUT THE POTENTIAL FOR MORE
WIDESPREAD MODERATE TO HEAVY RAIN EXISTS. CHAMBERS
&&
.AVIATION...
AN ISOLATED STRONG STORM WILL BE POSSIBLE EARLY THIS MORNING IN
THE BAKER VICINITY...LIKELY EXITING THE AREA BEFORE 13Z. LOCAL
MVFR/IFR CONDITIONS WILL BE POSSIBLE NEAR THIS ACTIVITY ALONG WITH
ISOLATED LARGE HAIL AND STRONG WIND GUSTS.
VFR CONDITIONS WILL PREVAIL THIS AFTERNOON AND EVENING. SURFACE
WINDS WILL INCREASE WITH GUSTS 20 TO 35KTS COMMON THIS AFTERNOON.
ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER
HIGHER TERRAIN TO THE SOUTH AND MOVE THROUGH THE AREA THIS
AFTERNOON AND EARLY EVENING. A FEW SEVERE STORMS ARE POSSIBLE WITH
LARGE HAIL AND STRONG WINDS. LOCAL IFR CONDITIONS IN HEAVY RAIN
CAN BE EXPECTED NEAR STORMS. CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
TDY THU FRI SAT SUN MON TUE
-------------------------------------------------------
BIL 089 057/073 052/076 054/076 056/072 054/069 051/073
3/T 22/T 24/T 54/T 46/T 66/T 64/T
LVM 084 047/072 043/074 047/077 048/072 048/067 045/072
2/T 22/T 23/T 35/T 56/T 66/T 64/T
HDN 092 059/076 053/079 054/080 055/076 053/072 051/075
3/T 21/B 24/T 54/T 46/T 66/T 64/T
MLS 094 062/077 055/079 057/079 056/074 054/072 052/073
2/T 31/B 23/T 43/T 34/T 66/T 64/T
4BQ 094 063/078 055/077 056/079 056/077 055/075 052/074
1/U 21/B 45/T 54/T 44/T 66/T 65/T
BHK 089 062/078 054/076 054/076 052/072 051/070 050/070
2/T 21/B 44/T 64/T 44/T 66/T 64/T
SHR 091 056/075 050/075 049/078 049/075 049/072 046/073
2/T 23/T 35/T 55/T 56/T 66/T 64/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
356 PM CDT WED MAY 28 2014
.SYNOPSIS...
ISSUED AT 356 PM CDT WED MAY 28 2014
THE CENTRAL PLAINS ARE UNDERNEATH A LARGE 500HPA RIDGE AHEAD OF AN
INCOMING TROUGH AFFECTING THE PACIFIC NORTHWEST. THE AREA OF LOW
PRESSURE ALOFT HAS MOVED INTO THE MISSISSIPPI DELTA REGION. AT THE
SURFACE...ONE LOW PRESSURE SYSTEM EXISTS ACROSS THE FAR NORTHERN
PLAINS AND ONE OVER THE LOWER GREAT LAKES. HIGH PRESSURE SITUATED IN
SOUTHERN COLORADO COMBINED WITH THE UPPER LEVEL RIDGE ARE PROVIDING
HOT AND MAINLY DRY CONDITIONS TO NEBRASKA.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 356 PM CDT WED MAY 28 2014
ISOLATED THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON ACROSS PORTIONS
OF THE WESTERN SANDHILLS AND SOUTHWEST NEBRASKA. THE HRRR MODEL HAS
BEEN HINTING AT DEVELOPMENT FOR SEVERAL RUNS AND A CUMULUS FIELD
SHOWED UP ON VISIBLE SATELLITE EARLY AFTERNOON. IN ADDITION...MANY
LOCATIONS HAVE REACHED THE CONVECTIVE TEMPERATURE BASED ON THE
28/12Z KLBF RAOB. ANY THUNDERSTORM SHOULD DISSIPATE SHORTLY AFTER
SUNSET AS THE CAP STRENGTHENS. TEMPERATURE TRENDS FOR OVERNIGHT LOWS
AND THURSDAY HIGHS LOOKED GOOD FROM PREVIOUS FORECAST. ONLY CHANGES
WERE DROPPED A DEGREE OR SO TONIGHT BASED ON GUIDANCE AND THE DEW
POINT FORECAST...AND RAISED A DEGREE THURSDAY FOR CONTINUED SUNSHINE
AND SOUTH WINDS. MOISTURE ADVECTS INTO THE AREA THURSDAY AHEAD OF
THE NEXT WEATHER SYSTEM...AS SURFACE DEW POINTS REACH THE LOWER 60S
ACROSS NORTH CENTRAL NEBRASKA. ANY PRECIPITATION WILL HOLD OFF UNTIL
THE LONG TERM FORECAST PERIOD.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 356 PM CDT WED MAY 28 2014
AN ACTIVE WEATHER PATTERN WILL BE ONGOING ACROSS THE CENTRAL
PLAINS LATER THIS WEEK INTO NEXT WEEK.
THE UPPER LEVEL LOW CURRENTLY OVER ARKANSAS/LOUISIANA AND EASTERN
TEXAS WILL SEE LITTLE MOVEMENT OVER THE NEXT SEVERAL DAYS AS IT
BECOMES CUTOFF FROM THE GENERAL FLOW AND REMAINS NEARLY STATIONARY
UNDER THE RIDGE WHICH WILL BE CENTERED OVER THE NORTHERN PLAINS
AND UPPER MISSISSIPPI RIVER VALLEY AT 00Z FRIDAY. OVER THE NEXT
SEVERAL DAYS THE RIDGE AXIS WILL MOVE EASTWARD AS A STRONG TROUGH
MOVES ONSHORE OVER THE WEST COAST ON SATURDAY. THIS PATTERN SHIFT
WILL BRING STRONGER UPPER LEVEL FLOW TO THE REGION...ALONG WITH A
MULTITUDE OF WEAK BOUTS OF SHORTWAVE ENERGY FROM THE SOUTHWEST
FLOW INTO THE CENTRAL PLAINS.
ALTHOUGH THE MODELS ARE IN GOOD CONSENSUS WITH THE GENERAL
PATTERN...THERE IS SOME DISCONTINUITY ON THE TRACK OF THE
SHORTWAVES AS WELL AS THE MOVEMENT OF THE LONGWAVE TROUGH OUT WEST
INTO NEXT WEEK. THEREFORE...USED A MODEL CONSENSUS FOR MUCH OF THE
LONG TERM PORTION OF THE FORECAST AS CONFIDENCE ISN/T REAL HIGH ON
TIMING OF PRECIPITATION CHANCES.
STARTING THURSDAY EVENING...RIDGING IS STILL WELL IN PLACE ACROSS
THE CENTRAL PLAINS AND WITH THE MID-LEVEL FLOW NORTH-NORTHWEST
CONVECTION DEVELOPING ACROSS NORTHERN COLORADO AND THE WESTERN
PANHANDLE MAY JUST SKIRT THE NORTHWEST PART OF THE FORECAST AREA.
SO LIMITED THE CHANCES FOR SHOWERS AND STORMS TO PORTIONS OF
SHERIDAN COUNTY.
DURING THE DAY ON FRIDAY...SHOWER AND STORM CHANCES WILL AGAIN BE
CONFINED TO AREAS OVER THE WESTERN PART OF THE FORECAST
AREA...MAINLY THE PANHANDLE AND THE WESTERN SANDHILLS AS
CONVECTION SHOULD DEVELOP OVER THE HIGHER ELEVATIONS ACROSS
COLORADO AND THE WESTERN PANHANDLE WHERE THERE WILL BE BETTER
SHORTWAVE ENERGY...ALONG WITH SOME UPSLOPE FLOW AND A FOCUS OF
MOISTURE TRANSPORT. THE LOW LEVEL JET WILL VEER INTO THE EVENING
WHICH WILL THEN SUPPORT STORMS TRANSITIONING EAST ACROSS NORTHERN
NEBRASKA AND INTO SOUTH DAKOTA. PRECIPITATION CHANCES HAVE BEEN
TRENDED IN THIS DIRECTION.
ON SATURDAY A FAIRLY STRONG SHORTWAVE TROUGH IS EXPECTED TO MOVE
ACROSS THE NORTHERN PLAINS AND INTO NORTHERN NEBRASKA. THIS WILL
PUSH A COLD FRONT INTO THE FORECAST AREA THROUGH THE DAY HOWEVER
IT DOESN/T LOOK TO PROGRESS VERY FAR EAST. EXPECTING TO GET
DEVELOPMENT ALONG THE FRONT SATURDAY AFTERNOON. ANY STORMS
DEVELOPING ON SATURDAY COULD GET STRONG TO SEVERE AS THE INCREASE
IN THE UPPER LEVEL FLOW WILL HELP TO STRENGTHEN THE DEEP LAYER
SHEAR TO GET STORMS HAVE THE POTENTIAL TO BECOME MORE ORGANIZED.
BEYOND SATURDAY IS WHEN THE DIFFERENCES IN TIMING OF ANY SHORTWAVE
ENERGY MOVING THROUGH THE AREA BECOME MORE APPARENT. SO THE
CHANCES FOR SHOWERS AND THUNDERSTORMS FOR MUCH OF THE AREA
CONTINUE DAILY THROUGH THE EARLY PORTIONS OF NEXT WEEK. ALTHOUGH
SEVERE STORMS ARE NOT OUT OF THE QUESTION ANY DAY AS THERE SHOULD
BE DECENT INSTABILITY AND WIND SHEER EACH DAY...THERE ISN/T A PERIOD
THAT LOOKS BETTER THAN OTHERS TO HIGHLIGHT THE CHANCES FOR SEVERE
STORMS.
AS FOR TEMPERATURES...FRIDAY WILL BE ANOTHER WARM DAY WITH HIGHS
IN THE MID TO UPPER 80S. ON SATURDAY...THE NORTHWEST MAY BE A BIT
COOLER IN THE 70S AS THE COLD FRONT MOVES THROUGH THAT
AREA...WITH THE REMAINDER OF THE FORECAST AREA IN THE 80S. THEN
THE REST OF THE FORECAST PERIOD HAS HIGHS IN THE 70S AND 80S AS
SHOWERS/STORMS/CLOUDS WILL PLAGUE MUCH OF THE AREA KEEPING
TEMPERATURES IN CHECK. AS FOR LOWS...DEWPOINTS IN THE UPPER 40S TO
LOW 60S THROUGHOUT THE PERIOD WILL KEEP TEMPERATURES FROM FALLING
TOO FAR AND WILL STAY SLIGHTLY ABOVE NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1223 PM CDT WED MAY 28 2014
VFR CONDITIONS WILL CONTINUE ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA INTO THURSDAY AFTERNOON. ISOLATED THUNDERSTORMS ARE
POSSIBLE THIS EVENING...BUT THE STORMS WILL LIKELY STAY SOUTH OF
KVTN AND NORTH OF KLBF. WIND MAY BE A CONCERN...MAINLY FOR KVTN...AS
SOUTH/SOUTHEAST WIND GUSTS TO NEAR 20 KTS WILL BE POSSIBLE THIS
EVENING AND AGAIN THURSDAY. ALSO...A LOW LEVEL JET MAY FORM
OVERNIGHT AND PRODUCE WINDS TO AROUND 25 KTS AT ABOUT 1000 FT AGL AT
KLBF AND 35 KTS AT KVTN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DS
SHORT TERM...DS
LONG TERM...BROOKS
AVIATION...DS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
138 PM CDT WED MAY 28 2014
.UPDATE...
ISSUED AT 137 PM CDT WED MAY 28 2014
BASED ON LATER MODEL RUNS BY THE HRRR AND CUMULUS DEVELOPMENT
UNDERWAY...HAVE SHIFTED ISOLATED THUNDERSTORM MENTION FARTHER
WEST. REMOVED MENTION OF POPS IN NORTH CENTRAL NEBRASKA AND PLACED
THE MAJORITY OF ISOLATED THUNDERSTORMS WEST OF HWY 83.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT WED MAY 28 2014
TODAY AND TONIGHT...A CHECK OF THE HRRR AND RAP MODELS INDICATE
THE CAP WILL BE WEAK ENOUGH ACROSS THE CNTL SANDHILLS THIS AFTN
FOR SOME ISOLATED TSTM DEVELOPMENT...THE INHIBITION AT 22Z WAS 20
TO 40 J/KG IN THE RAP. SO A SMALL AREA OF ISOLATED POP IS IN PLACE
ACROSS THE CNTL SANDHILLS. CAPE AND SHEAR ARE WEAK AROUND 1000
J/KG AND 20 KTS IN A NRLY FLOW ALOFT. THIS HOWEVER IS THE PROPER
BALANCE FOR WEAKLY ROTATING TSTMS AS INDICATED BY THE BULK
RICHARDSON NUMBER AROUND 45 SO A FEW STRONG OR AN ISOLATED SEVERE
TSTMS ARE POSSIBLE.
THE TEMPERATURE FORECAST STRATEGY IS SIMILAR TO YESTERDAY USING
THE WARMER GUIDANCE NUMBERS FOR HIGHS IN THE UPPER 80S TO NEAR 90.
H700 MB TEMPERATURES WILL WARM A COUPLE OF DEGREES TODAY.
LOWS TONIGHT FALL INTO THE UPPER 50S TO LOWER 60S. WE WILL BE
PICKING UP A 20 TO 40 KT SLY LOW LEVEL JET TONIGHT WHICH WOULD
KEEP THE ATMOSPHERE WELL MIXED...ESPECIALLY ACROSS SHERIDAN
COUNTY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 358 AM CDT WED MAY 28 2014
POSITIVELY TILTED RIDGE FROM THE 4 CORNERS TO THE NORTHERN PLAINS
WILL BRING A SUMMER LIKE END TO MAY. HIGHS ON THURSDAY IN THE MID
80S TO AROUND 90 IN THE WEST. A TROUGH WILL DEVELOP ALONG THE
ROCKIES AND NORTHERN PLAINS...WITH THUNDERSTORMS EXPECTED TO FIRE
NEAR THE BOUNDARY. GENERALLY THINK THE ACTIVITY WILL LIFT
NORTHEAST AND COULD CLIP THE FAR NORTHWESTERN PART OF THE CWA
OTHERWISE CAP SHOULD HOLD. FRIDAY WILL BEGIN AS THURSDAY...HOWEVER
THE BOUNDARY TO THE WEST WILL BEGIN TO PUSH EAST DURING THE DAY.
AS TEMPS WARM...CAP WEAKENS WITH THUNDERSTORMS EXPECTED ACROSS THE
WESTERN CWA FOR THE AFTERNOON. THE CLOUDS/STORMS WILL HOLD TEMPS
DOWN IN THE LOWER TO MID 80S...WITH MID 80S TO THE EAST. OVERNIGHT
THE BOUNDARY CONTINUES TO PUSH EAST WITH GULF MOISTURE TO BE ON
THE INCREASE. LL JET SHOULD SUSTAIN/EXPAND THUNDERSTORM COVER
DURING THE NIGHT. SHEAR IS ON THE INCREASE AND THINK ANY STORMS
THAT DEVELOP WILL HAVE THE ABILITY TO BECOME SEVERE.
UPPER LEVEL TROUGH STALLS ACROSS THE NORTHERN ROCKIES FOR THE
WEEKEND AND TO START OFF NEXT WEEK. SOUTHWEST FLOW WILL PREVAIL
FOR HIGH PLAINS WITH SEVERAL UPPER LEVEL DISTURBANCES TO PUSH
ACROSS THE REGION. WITH EACH PASSING WAVE ALONG WITH PEAK
HEATING...THUNDERSTORM DEVELOP IS EXPECTED. TIMING/COVERAGE STILL
IN QUESTION AND WILL WAIT TO UP POPS ABOVE HIGH CHANCE. WITH THE
ADDITIONAL CLOUDS AND ADVECTING SLIGHTLY COOLER AIR FROM THE
NW...HIGHS IN THE UPPER 70S TO MID 80S. WARMEST WHERE BREAKS IN
CLOUDS APPEAR...ANTICIPATED IN THE SOUTHERN CWA.
MODEL DIFFERENCES INCREASE AS WE GET INTO NEXT WEEK. GENERALLY
STILL THINKING SW FLOW...HOWEVER STORM CHANCES LESSEN AS A WEAK
COLD FRONT PUSHES ACROSS THE AREA ON MONDAY INTO TUESDAY. HIGHS
BEHIND THE FRONT DROP TO SEASONAL MID 70S TO AROUND 80.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1223 PM CDT WED MAY 28 2014
VFR CONDITIONS WILL CONTINUE ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA INTO THURSDAY AFTERNOON. ISOLATED THUNDERSTORMS ARE
POSSIBLE THIS EVENING...BUT THE STORMS WILL LIKELY STAY SOUTH OF
KVTN AND NORTH OF KLBF. WIND MAY BE A CONCERN...MAINLY FOR KVTN...AS
SOUTH/SOUTHEAST WIND GUSTS TO NEAR 20 KTS WILL BE POSSIBLE THIS
EVENING AND AGAIN THURSDAY. ALSO...A LOW LEVEL JET MAY FORM
OVERNIGHT AND PRODUCE WINDS TO AROUND 25 KTS AT ABOUT 1000 FT AGL AT
KLBF AND 35 KTS AT KVTN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DS
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...DS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1223 PM CDT WED MAY 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT WED MAY 28 2014
TODAY AND TONIGHT...A CHECK OF THE HRRR AND RAP MODELS INDICATE
THE CAP WILL BE WEAK ENOUGH ACROSS THE CNTL SANDHILLS THIS AFTN
FOR SOME ISOLATED TSTM DEVELOPMENT...THE INHIBITION AT 22Z WAS 20
TO 40 J/KG IN THE RAP. SO A SMALL AREA OF ISOLATED POP IS IN PLACE
ACROSS THE CNTL SANDHILLS. CAPE AND SHEAR ARE WEAK AROUND 1000
J/KG AND 20 KTS IN A NRLY FLOW ALOFT. THIS HOWEVER IS THE PROPER
BALANCE FOR WEAKLY ROTATING TSTMS AS INDICATED BY THE BULK
RICHARDSON NUMBER AROUND 45 SO A FEW STRONG OR AN ISOLATED SEVERE
TSTMS ARE POSSIBLE.
THE TEMPERATURE FORECAST STRATEGY IS SIMILAR TO YESTERDAY USING
THE WARMER GUIDANCE NUMBERS FOR HIGHS IN THE UPPER 80S TO NEAR 90.
H700 MB TEMPERATURES WILL WARM A COUPLE OF DEGREES TODAY.
LOWS TONIGHT FALL INTO THE UPPER 50S TO LOWER 60S. WE WILL BE
PICKING UP A 20 TO 40 KT SLY LOW LEVEL JET TONIGHT WHICH WOULD
KEEP THE ATMOSPHERE WELL MIXED...ESPECIALLY ACROSS SHERIDAN
COUNTY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 358 AM CDT WED MAY 28 2014
POSITIVELY TILTED RIDGE FROM THE 4 CORNERS TO THE NORTHERN PLAINS
WILL BRING A SUMMER LIKE END TO MAY. HIGHS ON THURSDAY IN THE MID
80S TO AROUND 90 IN THE WEST. A TROUGH WILL DEVELOP ALONG THE
ROCKIES AND NORTHERN PLAINS...WITH THUNDERSTORMS EXPECTED TO FIRE
NEAR THE BOUNDARY. GENERALLY THINK THE ACTIVITY WILL LIFT
NORTHEAST AND COULD CLIP THE FAR NORTHWESTERN PART OF THE CWA
OTHERWISE CAP SHOULD HOLD. FRIDAY WILL BEGIN AS THURSDAY...HOWEVER
THE BOUNDARY TO THE WEST WILL BEGIN TO PUSH EAST DURING THE DAY.
AS TEMPS WARM...CAP WEAKENS WITH THUNDERSTORMS EXPECTED ACROSS THE
WESTERN CWA FOR THE AFTERNOON. THE CLOUDS/STORMS WILL HOLD TEMPS
DOWN IN THE LOWER TO MID 80S...WITH MID 80S TO THE EAST. OVERNIGHT
THE BOUNDARY CONTINUES TO PUSH EAST WITH GULF MOISTURE TO BE ON
THE INCREASE. LL JET SHOULD SUSTAIN/EXPAND THUNDERSTORM COVER
DURING THE NIGHT. SHEAR IS ON THE INCREASE AND THINK ANY STORMS
THAT DEVELOP WILL HAVE THE ABILITY TO BECOME SEVERE.
UPPER LEVEL TROUGH STALLS ACROSS THE NORTHERN ROCKIES FOR THE
WEEKEND AND TO START OFF NEXT WEEK. SOUTHWEST FLOW WILL PREVAIL
FOR HIGH PLAINS WITH SEVERAL UPPER LEVEL DISTURBANCES TO PUSH
ACROSS THE REGION. WITH EACH PASSING WAVE ALONG WITH PEAK
HEATING...THUNDERSTORM DEVELOP IS EXPECTED. TIMING/COVERAGE STILL
IN QUESTION AND WILL WAIT TO UP POPS ABOVE HIGH CHANCE. WITH THE
ADDITIONAL CLOUDS AND ADVECTING SLIGHTLY COOLER AIR FROM THE
NW...HIGHS IN THE UPPER 70S TO MID 80S. WARMEST WHERE BREAKS IN
CLOUDS APPEAR...ANTICIPATED IN THE SOUTHERN CWA.
MODEL DIFFERENCES INCREASE AS WE GET INTO NEXT WEEK. GENERALLY
STILL THINKING SW FLOW...HOWEVER STORM CHANCES LESSEN AS A WEAK
COLD FRONT PUSHES ACROSS THE AREA ON MONDAY INTO TUESDAY. HIGHS
BEHIND THE FRONT DROP TO SEASONAL MID 70S TO AROUND 80.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1223 PM CDT WED MAY 28 2014
VFR CONDITIONS WILL CONTINUE ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA INTO THURSDAY AFTERNOON. ISOLATED THUNDERSTORMS ARE
POSSIBLE THIS EVENING...BUT THE STORMS WILL LIKELY STAY SOUTH OF
KVTN AND NORTH OF KLBF. WIND MAY BE A CONCERN...MAINLY FOR KVTN...AS
SOUTH/SOUTHEAST WIND GUSTS TO NEAR 20 KTS WILL BE POSSIBLE THIS
EVENING AND AGAIN THURSDAY. ALSO...A LOW LEVEL JET MAY FORM
OVERNIGHT AND PRODUCE WINDS TO AROUND 25 KTS AT ABOUT 1000 FT AGL AT
KLBF AND 35 KTS AT KVTN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...DS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
616 AM CDT WED MAY 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT WED MAY 28 2014
TODAY AND TONIGHT...A CHECK OF THE HRRR AND RAP MODELS INDICATE
THE CAP WILL BE WEAK ENOUGH ACROSS THE CNTL SANDHILLS THIS AFTN
FOR SOME ISOLATED TSTM DEVELOPMENT...THE INHIBITION AT 22Z WAS 20
TO 40 J/KG IN THE RAP. SO A SMALL AREA OF ISOLATED POP IS IN PLACE
ACROSS THE CNTL SANDHILLS. CAPE AND SHEAR ARE WEAK AROUND 1000
J/KG AND 20 KTS IN A NRLY FLOW ALOFT. THIS HOWEVER IS THE PROPER
BALANCE FOR WEAKLY ROTATING TSTMS AS INDICATED BY THE BULK
RICHARDSON NUMBER AROUND 45 SO A FEW STRONG OR AN ISOLATED SEVERE
TSTMS ARE POSSIBLE.
THE TEMPERATURE FORECAST STRATEGY IS SIMILAR TO YESTERDAY USING
THE WARMER GUIDANCE NUMBERS FOR HIGHS IN THE UPPER 80S TO NEAR 90.
H700 MB TEMPERATURES WILL WARM A COUPLE OF DEGREES TODAY.
LOWS TONIGHT FALL INTO THE UPPER 50S TO LOWER 60S. WE WILL BE
PICKING UP A 20 TO 40 KT SLY LOW LEVEL JET TONIGHT WHICH WOULD
KEEP THE ATMOSPHERE WELL MIXED...ESPECIALLY ACROSS SHERIDAN
COUNTY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 358 AM CDT WED MAY 28 2014
POSITIVELY TILTED RIDGE FROM THE 4 CORNERS TO THE NORTHERN PLAINS
WILL BRING A SUMMER LIKE END TO MAY. HIGHS ON THURSDAY IN THE MID
80S TO AROUND 90 IN THE WEST. A TROUGH WILL DEVELOP ALONG THE
ROCKIES AND NORTHERN PLAINS...WITH THUNDERSTORMS EXPECTED TO FIRE
NEAR THE BOUNDARY. GENERALLY THINK THE ACTIVITY WILL LIFT
NORTHEAST AND COULD CLIP THE FAR NORTHWESTERN PART OF THE CWA
OTHERWISE CAP SHOULD HOLD. FRIDAY WILL BEGIN AS THURSDAY...HOWEVER
THE BOUNDARY TO THE WEST WILL BEGIN TO PUSH EAST DURING THE DAY.
AS TEMPS WARM...CAP WEAKENS WITH THUNDERSTORMS EXPECTED ACROSS THE
WESTERN CWA FOR THE AFTERNOON. THE CLOUDS/STORMS WILL HOLD TEMPS
DOWN IN THE LOWER TO MID 80S...WITH MID 80S TO THE EAST. OVERNIGHT
THE BOUNDARY CONTINUES TO PUSH EAST WITH GULF MOISTURE TO BE ON
THE INCREASE. LL JET SHOULD SUSTAIN/EXPAND THUNDERSTORM COVER
DURING THE NIGHT. SHEAR IS ON THE INCREASE AND THINK ANY STORMS
THAT DEVELOP WILL HAVE THE ABILITY TO BECOME SEVERE.
UPPER LEVEL TROUGH STALLS ACROSS THE NORTHERN ROCKIES FOR THE
WEEKEND AND TO START OFF NEXT WEEK. SOUTHWEST FLOW WILL PREVAIL
FOR HIGH PLAINS WITH SEVERAL UPPER LEVEL DISTURBANCES TO PUSH
ACROSS THE REGION. WITH EACH PASSING WAVE ALONG WITH PEAK
HEATING...THUNDERSTORM DEVELOP IS EXPECTED. TIMING/COVERAGE STILL
IN QUESTION AND WILL WAIT TO UP POPS ABOVE HIGH CHANCE. WITH THE
ADDITIONAL CLOUDS AND ADVECTING SLIGHTLY COOLER AIR FROM THE
NW...HIGHS IN THE UPPER 70S TO MID 80S. WARMEST WHERE BREAKS IN
CLOUDS APPEAR...ANTICIPATED IN THE SOUTHERN CWA.
MODEL DIFFERENCES INCREASE AS WE GET INTO NEXT WEEK. GENERALLY
STILL THINKING SW FLOW...HOWEVER STORM CHANCES LESSEN AS A WEAK
COLD FRONT PUSHES ACROSS THE AREA ON MONDAY INTO TUESDAY. HIGHS
BEHIND THE FRONT DROP TO SEASONAL MID 70S TO AROUND 80.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 615 AM CDT WED MAY 28 2014
VFR IS GENERALLY EXPECTED ALL AREAS TODAY AND TONIGHT.
THE RAP AND HRRR MODELS INDICATE ISOLATED SHRA/TSTM DEVELOPMENT
21Z- 00Z TODAY ACROSS THE CENTRAL SANDHILLS BETWEEN KMUL-KTIF AND
PERHAPS AS FAR NORTH AS KVTN. STORM ACTIVITY SHOULD DISSIPATE
WITH THE LOSS OF HEATING AROUND 01Z.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
359 AM CDT WED MAY 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT WED MAY 28 2014
TODAY AND TONIGHT...A CHECK OF THE HRRR AND RAP MODELS INDICATE
THE CAP WILL BE WEAK ENOUGH ACROSS THE CNTL SANDHILLS THIS AFTN
FOR SOME ISOLATED TSTM DEVELOPMENT...THE INHIBITION AT 22Z WAS 20
TO 40 J/KG IN THE RAP. SO A SMALL AREA OF ISOLATED POP IS IN PLACE
ACROSS THE CNTL SANDHILLS. CAPE AND SHEAR ARE WEAK AROUND 1000
J/KG AND 20 KTS IN A NRLY FLOW ALOFT. THIS HOWEVER IS THE PROPER
BALANCE FOR WEAKLY ROTATING TSTMS AS INDICATED BY THE BULK
RICHARDSON NUMBER AROUND 45 SO A FEW STRONG OR AN ISOLATED SEVERE
TSTMS ARE POSSIBLE.
THE TEMPERATURE FORECAST STRATEGY IS SIMILAR TO YESTERDAY USING
THE WARMER GUIDANCE NUMBERS FOR HIGHS IN THE UPPER 80S TO NEAR 90.
H700 MB TEMPERATURES WILL WARM A COUPLE OF DEGREES TODAY.
LOWS TONIGHT FALL INTO THE UPPER 50S TO LOWER 60S. WE WILL BE
PICKING UP A 20 TO 40 KT SLY LOW LEVEL JET TONIGHT WHICH WOULD
KEEP THE ATMOSPHERE WELL MIXED...ESPECIALLY ACROSS SHERIDAN
COUNTY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 358 AM CDT WED MAY 28 2014
POSITIVELY TILTED RIDGE FROM THE 4 CORNERS TO THE NORTHERN PLAINS
WILL BRING A SUMMER LIKE END TO MAY. HIGHS ON THURSDAY IN THE MID
80S TO AROUND 90 IN THE WEST. A TROUGH WILL DEVELOP ALONG THE
ROCKIES AND NORTHERN PLAINS...WITH THUNDERSTORMS EXPECTED TO FIRE
NEAR THE BOUNDARY. GENERALLY THINK THE ACTIVITY WILL LIFT
NORTHEAST AND COULD CLIP THE FAR NORTHWESTERN PART OF THE CWA
OTHERWISE CAP SHOULD HOLD. FRIDAY WILL BEGIN AS THURSDAY...HOWEVER
THE BOUNDARY TO THE WEST WILL BEGIN TO PUSH EAST DURING THE DAY.
AS TEMPS WARM...CAP WEAKENS WITH THUNDERSTORMS EXPECTED ACROSS THE
WESTERN CWA FOR THE AFTERNOON. THE CLOUDS/STORMS WILL HOLD TEMPS
DOWN IN THE LOWER TO MID 80S...WITH MID 80S TO THE EAST. OVERNIGHT
THE BOUNDARY CONTINUES TO PUSH EAST WITH GULF MOISTURE TO BE ON
THE INCREASE. LL JET SHOULD SUSTAIN/EXPAND THUNDERSTORM COVER
DURING THE NIGHT. SHEAR IS ON THE INCREASE AND THINK ANY STORMS
THAT DEVELOP WILL HAVE THE ABILITY TO BECOME SEVERE.
UPPER LEVEL TROUGH STALLS ACROSS THE NORTHERN ROCKIES FOR THE
WEEKEND AND TO START OFF NEXT WEEK. SOUTHWEST FLOW WILL PREVAIL
FOR HIGH PLAINS WITH SEVERAL UPPER LEVEL DISTURBANCES TO PUSH
ACROSS THE REGION. WITH EACH PASSING WAVE ALONG WITH PEAK
HEATING...THUNDERSTORM DEVELOP IS EXPECTED. TIMING/COVERAGE STILL
IN QUESTION AND WILL WAIT TO UP POPS ABOVE HIGH CHANCE. WITH THE
ADDITIONAL CLOUDS AND ADVECTING SLIGHTLY COOLER AIR FROM THE
NW...HIGHS IN THE UPPER 70S TO MID 80S. WARMEST WHERE BREAKS IN
CLOUDS APPEAR...ANTICIPATED IN THE SOUTHERN CWA.
MODEL DIFFERENCES INCREASE AS WE GET INTO NEXT WEEK. GENERALLY
STILL THINKING SW FLOW...HOWEVER STORM CHANCES LESSEN AS A WEAK
COLD FRONT PUSHES ACROSS THE AREA ON MONDAY INTO TUESDAY. HIGHS
BEHIND THE FRONT DROP TO SEASONAL MID 70S TO AROUND 80.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1224 AM CDT WED MAY 28 2014
EARLIER TSRA WILL CONTINUE TO MOVE SOUTH ACROSS THE CENTRAL
SANDHILLS AREA BEFORE DISSIPATING. MID LEVEL CLOUDINESS
ASSOCIATED WITH THIS CONVECTION WILL ALSO DISSIPATE AT THE KVTN
TAF SITE. WINDS WILL INCREASE BY LATER AFTERNOON WED ESPECIALLY
ACROSS NC NEB IN RESPONSE TO LEE TROUGH DEVELOPMENT IN THE NRN
HIGH PLAINS AS UPPER RIDGE BUILDS INTO THE REGION AHEAD OF UPPER
LOW IN THE PAC NW. GUSTINESS SHOULD STILL REMAIN BELOW 20 KTS
THROUGH THE PERIOD. OTHERWISE VFR CONDITIONS WILL PREVAIL FOR THE
ENTIRE AREA THROUGH THE TAF PERIOD.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1225 AM CDT WED MAY 28 2014
.SYNOPSIS...
ISSUED AT 319 PM CDT TUE MAY 27 2014
UPPER CLOSED LOW OVER ARKALATEX THIS AFTERNOON. BROAD RIDGING INTO
CENTRAL CANADA WITH CLOSED LOW OVER PACIFIC NORTHWEST. AT 19Z WATER
VAPOR IMAGERY SHOWED A DEEP UPPER LEVEL LOW OVER SOUTH CENTRAL
OKLAHOMA AND NORTH CENTRAL TEXAS...WITH A TIGHT CIRCULATION
INDICATED IN THE VISIBLE SATELLITE AS WELL. RIDGING BUILT OVER THE
NORTHERN AND CENTRAL PLAINS...AS THE RIDGE AXIS WAS ORIENTED FROM
THE DESERT SOUTHWEST INTO WESTERN NEBRASKA AND SOUTH DAKOTA. THE
EAST HALF OF THE COUNTRY WAS LITTERED WITH SHOWER AND THUNDERSTORM
ACTIVITY WHILE THE WESTERN HALF OF THE COUNTRY WAS GENERALLY DRY.
AT THE SURFACE...TEMPERATURES HAD RISEN INTO THE 80S IN MOST
LOCATIONS...WITH SCATTERED CUMULUS SEEN OVER MUCH OF THE AREA.
THERE WAS A COLD FRONT LOCATED FROM NORTHEAST SOUTH DAKOTA INTO
THE NORTHWEST NEBRASKA PANHANDLE...WITH SLIGHTLY COOLER
TEMPERATURES BEHIND THE FRONT IN THE 70S.
&&
.UPDATE...
ISSUED AT 859 PM CDT TUE MAY 27 2014
CONTINUING TO ADJUST PRECIP CHANCES ACROSS THE AREA AS WEAK PV
ANOMALY MOVES EWD ACROSS SD WHICH IS THE MAIN DRIVER FOR THE
CONVECTIVE DEVELOPMENT INITIALLY...HOWEVER OUTFLOW CONTINUES TO
DEVELOP NEW CONVECTION AS IT MOVES SWD. HRRR SEEMS TO HAVE A GOOD
HANDLE ON THIS AND BRINGS THE ISOLATED TSRA INTO THE NORTH CENTRAL
ZONES THROUGH 08Z OR SO. NEW DEVELOPMENT CONTINUES TO BE MAINLY
MULTICELL WITH BRIEF UPDRAFT ENHANCEMENTS TO NEAR SVR LEVELS
BEFORE COLLAPSING. HAVE INCREASED CHCS ACROSS THE NC ZONES INTO
THE EARLY MORNING HOURS. REST OF FCST REMAINS UNCHANGED.
UPDATE ISSUED AT 652 PM CDT TUE MAY 27 2014
ADJUSTED GRIDDED FORECAST POPS SLIGHTLY TO MORE CLOSELY MATCH
CURRENT TRENDS...BUT WORDING REMAINED THE SAME. ISOLATED TSRA
DRIFTING SLOWLY SOUTH AND TYPICAL OF PULSE TYPE STORMS. STORMS
IN SD HAVE EXPANDED SOUTHWARD ALONG OUTFLOW BOUNDRY AND MOVING
SEWD. WRN FRINGE OF THIS COLLIDED WITH ANOTHER BOUNDRY JUST EAST
OF BLACK HILLS RECENTLY TO PRODUCE ADDITIONAL STORMS. WILL BE
MONITORING THESE TRENDS AS CURRENT FORECAST DOES NOT BRING THESE
INTO THE FCST AREA TONIGHT DUE TO LACK OF LLJ TO PRODUCE LIFTING
ALONG OUTFLOW. HOWEVER WILL HAVE TO WATCH FOR ADDITIONAL
DEVELOPMENT. OTHERWISE REMAINDER OF FCST REMAINS THE SAME.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 319 PM CDT TUE MAY 27 2014
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE INTO
THE EARLY EVENING HOURS. SURFACE CAPE AS OF 19Z RANGED FROM 500J/KG
TO 2500J/KG ACROSS THE FORECAST AREA WITH THE HIGHER VALUES UP NEAR
AND BEHIND THE COLD FRONT. MOISTURE IN THE MID LEVELS IS LIMITED AND
ALTHOUGH HAVE THE INSTABILITY NOT EXPECTING WIDESPREAD COVERAGE OF
ACTIVITY THROUGH EARLY EVENING OVER MUCH OF THE AREA. MAY GET A FEW
STORMS TO DEVELOP BEHIND THE FRONT...BUT WITH NO LOW LEVEL JET
TONIGHT TO HELP FUEL ANY STORMS EXPECT ACTIVITY TO DIMINISH QUICKLY
AFTER SUNSET. IF THERE ARE ANY STORMS AROUND...THE FLOW IN THE
STEERING LAYER IS LIGHT SO SLOW MOVEMENT IS EXPECTED. AND IN TERMS
OF SEVERE POTENTIAL...WIND SHEAR IS LOW SO DON/T THINK ANY STORMS
LOCALLY WILL BE ABLE TO GET ORGANIZED TO THE POINT OF BEING
SEVERE...AT LEAST NOT IN A SUSTAINED MANNER.
SKIES SHOULD BE MOSTLY CLEAR TONIGHT AND WEDNESDAY AS THE RIDGE
CONTINUES TO BUILD INTO THE PLAINS BRINGING PLENTIFUL DRY AIR WITH
IT. DEWPOINTS IN THE 50S TONIGHT WILL KEEP LOWS MILD...BUT EVEN WITH
LIGHT WINDS...NOT EXPECTING TEMPERATURES TO FALL ENOUGH TO REACH
SATURATION AND DEVELOP FOG. THEN FOR WEDNESDAY...700MB TEMPERATURES
RISE 2-4 DEGREES COMPARED TO THIS AFTERNOON. WITH THE DRY AIR IN
PLACE...LOOKING FOR MIXING TO 700-750MB WHICH WOULD WARM
TEMPERATURES INTO THE UPPER 80S AND POSSIBLY REACH THE 90 DEGREE
MARK IN SOME LOCATIONS. ALTHOUGH LAPSE RATES WILL BE STEEP...WINDS
THROUGH THE MIXED LAYER WILL BE FAIRLY LIGHT SO EVEN WITH INCREASING
WINDS IN THE AFTERNOON FROM THE SOUTH AS HIGH PRESSURE MOVES
EAST...WON/T GET GUSTS TO MUCH OVER 15-20MPH IN THE AFTERNOON.
ALSO...THE FORECAST STAYS DRY FOR WEDNESDAY AS THERE WILL NOT BE
ENOUGH MOISTURE TO CAUSE THE DEVELOPMENT OF SHOWERS OR STORMS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 319 PM CDT TUE MAY 27 2014
MODELS IN FAIR AGREEMENT IN MID TERM AND THEN DIFFER DRAMATICALLY
THROUGH THE EXTENDED WITH ECMWF DRAWING MUCH COLDER AIR SOUTH INTO
THE NORTHERN PLAINS AFTER FRIDAY WHILE GFS CONTINUES UPWARD TREND
WITH TEMPERATURES RISING INTO THE 90S THROUGH NEXT WEEK. ANOTHER
MAJOR DIFFERENCE BETWEEN THE TWO MODELS IS GFS SENDS REMNANTS OF
AMANDA INTO THE PACIFIC WHILE ECMWF DRAGS REMNANTS THROUGH DESERT
SOUTHWEST. CURRENT FORECAST IS HOLDING TEMPERATURES UP AND WILL
GENERALLY TREND TOWARDS THE GFS FORECAST. STRONG SOUTHERLY FLOW
WEDNESDAY NIGHT OVER WESTERN NEBR SKA UNDER THE UPPER RIDGE WITH
CLEAR SKIES. TEMPERATURES TO BOTTOM OUT AROUND 60. SURFACE TROUGH
ALONG THE FRONT RANGE THURSDAY WITH UPPER TROUGH PUSHING EAST
THUNDERSTORMS EXPECTED OVER THE WESTERN PANHANDLE. HAVE LEFT
NORTHWEST DRY FOR NOW WITH BETTER DYNAMICS TO THE WEST. SIMILAR
CONDITIONS FRIDAY WITH THUNDERSTORMS EXPECTED TO PUSH EAST INTO
THE WESTERN NEBRASKA SANDHILLS LATE AFTERNOON AND THROUGH THE
NIGHT FRIDAY AS A STRONG WAVE MOVES OUT OF THE TROUGH TO THE WEST.
DEW POINTS INTO THE 60S ON SATURDAY...STRONG WARM AIR ADVECTION
AHEAD OF DEEPENING SURFACE LOW AND GOOD SHEER SETUP FOR SEVERE
WEATHER. INCREASED POPS AND SPREAD THEM ACROSS THE FORECAST AREA
THROUGH THE DAY AND INTO SUNDAY WITH SIMILAR PATTERN TO SATURDAY.
TEMPERATURES SOMEWHAT COOLER WITH CLOUDINESS AND PRECIPITATION
WITH NUMEROUS WAVES MOVING OUT OF TROUGH TO THE WEST HAVE CHANCES
OF TRW IN FORECAST THROUGH TUESDAY. HIGH TEMPERATURES IN THE 80S
AND LOWS IN THE 50S AND 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1224 AM CDT WED MAY 28 2014
EARLIER TSRA WILL CONTINUE TO MOVE SOUTH ACROSS THE CENTRAL
SANDHILLS AREA BEFORE DISSIPATING. MID LEVEL CLOUDINESS ASSOCIATED
WITH THIS CONVECTION WILL ALSO DISSPATE AT THE KVTN TAF SITE. WINDS
WILL INCREASE BY LATER AFTERNOON WED ESPECIALLY ACROSS NC NEB IN
RESPONSE TO LEE TROUGH DEVELOPMENT IN THE NRN HIGH PLAINS AS UPPER
RIDGE BUILDS INTO THE REGION AHEAD OF UPPER LOW IN THE PAC NW.
GUSTINESS SHOULD STILL REMAIN BELOW 20 KTS THROUGH THE PERIOD.
OTHERWISE VFR CONDITIONS WILL PREVAIL FOR THE ENTIRE AREA THROUGH
THE TAF PERIOD.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JWS
SYNOPSIS...POWER/BROOKS
SHORT TERM...BROOKS
LONG TERM...POWER
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1000 PM EDT THU MAY 29 2014
.SYNOPSIS...A STALLED COLD FRONT WILL LINGER NEAR THE SOUTH CAROLINA
BORDER THROUGH FRIDAY...WHILE HIGH PRESSURE BUILDS IN FROM THE NORTH
FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 PM THURSDAY...
QUICK UPDATE EARLIER LOWERED PRECIP CHANCES (EXCEPT FOR THE FAR SW
CWA) AND CUT WAY DOWN ON THUNDER PROBABILITIES... AND LATEST DATA
SUPPORTS MAINTAINING THIS PLAN THROUGH THE REMAINDER OF THE NIGHT.
MOST RECENT SURFACE MAP SHOWS THE BACKDOOR FRONT ORIENTED ROUGHLY
ALONG THE WRN AND SRN EDGES OF THE CWA... WITH VERY STABLE AIR
HAVING MOVED INTO THE NORTH AND EAST. THIS AFTERNOON`S CONVECTION
OVER THE SRN PIEDMONT/SRN SANDHILLS HAS PROPAGATED WESTWARD AND
CONGEALED INTO WIDESPREAD RAIN WITH EMBEDDED STORMS OVER THE FAR SW
EDGE OF THE CWA AND ADJACENT AREAS TO THE WEST AND SOUTH... SLOW-
MOVING AND MEANDERING WITH UPDRAFTS DRIVEN BY COLD POOL INTERACTIONS
WITHIN VERY WEAK DEEP LAYER SHEAR. PRECIP WATER VALUES ACCORDING TO
BLENDED TPW IMAGERY REMAIN CLOSE TO 150% OF NORMAL ACROSS THE
REGION... AND IT WILL NOT TAKE MUCH TO SET OFF A SHOWER WITHIN THIS
SOMEWHAT SOUPY AIR MASS TONIGHT... ALTHOUGH FORCING FOR ASCENT IS
RATHER WEAK AND LIMITED TO MINOR MASS CONVERGENCE ALONG THE LOW
LEVEL FRONTAL ZONE AND SUBTLE PASSING MID LEVEL PERTURBATIONS IN
LIGHT MAINLY NW STEERING FLOW. WILL HOLD ONTO A LOW CHANCE OF
SHOWERS OVERNIGHT... AS INDICATED BY THE RECENT HRRR RUNS... BUT
RETAIN HIGHER POPS IN THE SW FOR THE NEXT SEVERAL HOURS WITH
LINGERING MARGINAL INSTABILITY (ALTHOUGH CINH IS GROWING). AS
COOLER/DRIER AND MORE STABLE LOW LEVEL AIR CONTINUES TO POUR IN FROM
THE NE... EXPECT LOWS CLOSE TO SEASONAL NORMALS DESPITE THE BLANKET
OF CLOUD COVER (STRATUS AND CONVECTIVE DEBRIS)... 61 IN THE NE TO 67
IN THE SW. -GIH
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 245 PM THURSDAY...
OVERCAST SKIES FRIDAY MORNING WILL START TO BREAK APART DURING THE
DAY AS THE DRY AIR ADVECTING INTO THE MID LEVELS MIXES DOWN...WITH
MANY PLACES BECOMING PARTLY SUNNY BY THE AFTERNOON. THE FRONTAL
BOUNDARY WILL REAMIN IN THE VICINITY OF CENTRAL NC...WHICH WILL
RESULT IN A TEMP GRADIENT OF APPROX 5-10 DEGREES FROM SW TO NE...
HIGHS MAINLY IN THE MID 70S NE TO MID 80S SW. WITH THE BEST MOISTURE
AND HIGHEST TEMPS IN THE SOUTH AND SOUTHWEST FRIDAY...EXPECT BEST
INSTABILITY AND POTENTIAL FOR CONVECTION THERE. THOUGH THE
ATMOSPHERE WILL CONTINUE TO DRY OUT OVERNIGHT...SOME LOW STRATUS
COULD DEVELOP...MAINLY ACROSS THE SW HALF OF THE AREA. OVERNIGHT
LOWS EXPECTED TO RANGE FROM MID 50S NE TO MID 60S SOUTH.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 245 PM THURSDAY...
TO BEGIN THE LONG TERM PERIOD...FAIRLY STRONG HIGH PRESSURE (~1025
MB) WILL BUILD DOWN THE EAST COAST AND PERSIST OVER THE REGION
THROUGH AT LEAST THE WEEKEND. THIS WILL PUSH THE FRONT EVEN FURTHER
SOUTH...WITH DRIER AIR FINALLY ABLE TO FILTER INTO THE AREA.
ALOFT...SHORTWAVE RIDGING WILL BUILD EAST THROUGH EARLY NEXT WEEK.
ALL OF THIS WILL VIRTUALLY BRING AN END TO OUR PRECIP CHANCES WITH
STABLE NORTHEASTERLY FLOW DOMINATING. TEMPS WILL BE SLIGHTLY BELOW
NORMAL OVER THE WEEKEND...WITH HIGHS GENERALLY IN THE UPPER 70S TO
LOWER 80S AND OVERNIGHT LOWS IN THE MID TO UPPER 50S.
SURFACE HIGH PRESSURE WILL THEN SHIFT OFFSHORE BY LATE MONDAY...
ALLOWING THE LOW LEVEL FLOW TO GRADUALLY BECOME MORE SOUTHWESTERLY.
THIS WILL RESULT IN INCREASING MOISTURE...AS WELL AS A MODERATION IN
TEMPS. THERE IS SOME DISAGREEMENT WITH REGARDS TO THE EVOLUTION OF
THE UPPER RIDGE...WITH THE GFS QUICKER TO BREAK IT DOWN AND THE
ECMWF MAINTAINING THE RIDGE OVER THE AREA THROUGH THE MIDDLE OF THE
WEEK. WITH THE FLATTENING OF THE RIDGE DEPICTED BY THE GFS...PRECIP
CHANCES INCREASE AS EARLY AS TUESDAY. THIS MAY BE TOO QUICK (AS THE
GFS ENDS TO BREAK RIDGES DOWN TOO QUICKLY)...THEREFORE WILL HOLD OFF
INTRODUCING DIURNAL SHOWER/THUNDERSTORM ACTIVITY UNTIL WEDNESDAY AND
THEN EVEN MORE SO INTO THURSDAY. TEMPS SHOULD RISE BACK ABOVE
NORMAL...WITH A RETURN TO 90S BY THE MIDDLE OF THE WEEK.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 834 PM THURSDAY...
24 HOUR TAF PERIOD: CONDITIONS WILL DETERIORATE AGAIN OVERNIGHT AS
SUB-VFR STRATUS DEVELOPS IN A NORTHEASTERLY TO EASTERLY FLOW REGIME
WITH MOIST LOW LEVELS. A PERIOD OF VLIFR CONDITIONS IS POSSIBLE IN
THE MORNING BETWEEN 10Z-14Z. CONDITIONS WILL RETURN TO MVFR ACROSS
THE REGION AFTER THIS TIME. SHOWERS AND THUNDERSTORMS WILL DEVELOP
AGAIN IN THE AFTERNOON AND EVENING HOURS FRIDAY... HOWEVER...
CONFIDENCE IN ANY ONE SITE SEEING THIS ACTIVITY IS TOO LOW TO
WARRANT MENTION AT THIS TIME.
LOOKING AHEAD: SUB-VFR CEILINGS WILL LIKELY PERSIST THROUGH FRIDAY
NIGHT..ALTHOUGH A PERIOD OF VFR CONDITIONS IS POSSIBLE FRIDAY
AFT/EVE. EXPECT VFR CONDITIONS TO RETURN SAT-MON AS DRY HIGH
PRESSURE EXTENDS INTO THE REGION FROM THE NORTH. THE NEXT CHANCE FOR
SUB-VFR CONDITIONS WILL BE TUESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...HARTFIELD
SHORT TERM...KC
LONG TERM...KRD
AVIATION...SEC/KC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1007 AM EDT WED MAY 28 2014
.SYNOPSIS...
WARM AND HUMID CONDITIONS ARE EXPECTED TODAY AND TOMORROW WITH
SCATTERED AFTERNOON AND EVENING THUNDERSTORMS. A COLD FRONT WILL
DROP SOUTH ACROSS THE CAROLINAS THURSDAY INTO FRIDAY BRINGING A
GOOD CHANCE OF RAIN. HIGH PRESSURE WILL BUILD FROM THE NORTH OVER
THE WEEKEND...BRINGING DRIER AND SLIGHTLY COOLER AIR. A WARMING
TREND IS EXPECTED EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM WEDNESDAY...SINKING AIR IN WAKE OF AN IMPULSE ALOFT
PRESENTLY HEADING FARTHER OFFSHORE OF CAPE FEAR WILL LIKELY KEEP
CONVECTION CAPPED THROUGH AT LEAST THE MORNING HOURS. INTERESTING
FEATURE UPSTREAM OVER SC...A COALESCENCE OF LIGHT SHOWERS TRACKING
NE AND APPROACHING FLORENCE SC. THE ATMOSPHERE MAY NOT BE
CONDUCIVE FOR CONVECTIVE REGENERATION THIS EARLY BUT SOMETHING TO
WATCH.
NEAR TERM MODEL GUIDANCE REGARDING CONVECTIVE INITIATION TIMING
POINTS TO BLOSSOMING SHOWERS AND TSTMS BETWEEN 18Z-20Z/2PM-4PM
OVER INTERIOR ZONES AND THE COAST NORTH OF CAPE FEAR...SPREADING
E-SE LATE AFTERNOON INTO EVENING. IT APPEARS WE WILL STILL HAVE
SOME DEGREE OF UNFAVORABLE CLOCKWISE TURING OF THE ATMOSPHERE OVER
OUR AREA...AS A SHORT-WAVE UPPER RIDGE DRIFTS EAST...AHEAD OF A
LARGE UPPER LOW OVER LOUISIANA. THIS IS EVIDENT IN DEPICTIONS OF
RH THROUGH TIME AND HEIGHT...SHOWING A DRY H7-H6 LAYER THIS AFTN.
THIS MAY NOT BE ENOUGH TO COMPLETELY SHUT DOWN CONVECTION BUT IT
COULD LIMIT THE STRENGTH AND THREAT OF TSTMS LATER TODAY. WITH
STRONG SUNSHINE AND ELEVATED PRECIPITABLE WATER CONTENT WE CAN
EXPECTED A ROUND OF DIURNALLY INDUCED CONVECTION.
MAX TEMPS LOWER 90S INLAND LOOKS ON TARGET WITH PLENTY SUNSHINE
STILL WARMING THE GROUND SO NO CHANGES PLANNED TO TEMPERATURES.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...WARM AND CONVECTIVELY-ACTIVE WEATHER WILL
CONTINUE THROUGH THE SHORT TERM AS THIS SUMMER LIKE PATTERN REMAINS
OVER THE AREA. CLOSED 500MB LOW PRESSURE WILL DRIFT SOUTHEAST ALONG
THE GULF COAST THU...WITH A LARGE RIDGE BUILDING ATOP THIS
FEATURE. LOCALLY...THE AREA REMAINS PINCHED BETWEEN THE CLOSED LOW
NEAR THE GULF...AND AN EXPANSIVE TROUGH NEAR NEW ENGLAND. BY
THURSDAY HEIGHTS BEGIN TO CRASH AS THE NEW ENGLAND TROUGH PUSHES
SOUTH...DRIVING A WEAK COLD FRONT INTO THE AREA. HIGHS IN THE
MID/UPR 80S ACROSS THE CWA. LOWS BOTH NIGHTS WILL REMAIN
ELEVATED...AROUND 70 AT THE COAST AND UPR 60S INLAND.
MORE WIDESPREAD TSTMS LIKELY THURSDAY AS THE FRONT DROPS
SOUTH...SERVING AS AN ADDITIONAL FOCUS FOR STORMS. SPC HAS A SEE
TEXT ACROSS THE AREA FOR THURSDAY...BUT ATTM SEE ONLY LIMITED
SEVERE RISK WITH MLCAPES LESS THAN 1000 J/KG AND FORECAST
SOUNDINGS WHICH SUGGEST A LOT OF PRE-FRONTAL CLOUD COVER. EITHER
WAY...EXPECT QUITE A FEW SHOWERS/STORMS ON THE RADAR MOSAIC ON
THURSDAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...THE MID LEVEL PATTERN REMAINS ESSENTIALLY
UNCHANGED WITH THE LATEST SUITE OF GUIDANCE. INITIALLY A REX BLOCK
WILL BE THE MAIN FEATURE OVER THE CENTRAL U.S. WITH A TROUGH OF
LOW PRESSURE ALONG THE EAST COAST. AT THE SURFACE...HIGH PRESSURE
WILL BUILD IN FROM THE NORTH WITH DRIER CONDITIONS. PRECIPITABLE
WATERS WILL DROP FROM CURRENT APPROXIMATE VALUES OF 1.80 INCHES TO
THREE QUARTERS OF AN INCH OR LESS. MUCH LIKE WE SAW THIS
WEEKEND...A REFRESHING AIRMASS WILL BE NOTICEABLE BUT THE
TRANSITION WILL BE A LITTLE SLOWER. HAVE MAINTAINED THE MOSTLY
DIURNALLY DRIVEN POPS FOR FRIDAY AND SATURDAY WITH THE REMAINDER
OF THE PERIOD DRY. TEMPERATURE TRENDS ARE OF COURSE A LITTLE LOWER
IN TIME WITH THE AIRMASS CHANGE BUT LOWS REMAIN MOSTLY IN THE 60S
WITH HIGHS IN THE 80S.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
AS OF 14Z...RADAR INDICATES SHOWERS AND THUNDERSTORMS JUST
OFFSHORE OF KILM WITH ACTIVITY TRENDING FURTHER OFFSHORE. MVFR BR
HAS DEVELOPED IN THE MOIST HUMID AIRMASS AT KLBT.
VFR EXPECTED ALL TERMINALS SHORTLY AFTER 12Z. IN THE WAKE OF THE
CONVECTION CURRENTLY MOVING OFFSHORE DO NOT EXPECT ANY RE-DEVELOPMENT
UNTIL AFTER 18Z. IN AGREEMENT WITH THE HRRR THAT ACTIVITY THAT
DEVELOPS WILL BE FOCUSED AROUND AN OLD OUTFLOW BOUNDARY/SEA BREEZE
BOUNDARY NEAR KMYR/KCRE. SOME OF THIS ACTIVITY COULD REACH AS FAR
W AS KFLO/KLBT. DUE TO DRIER AIR IN THE MID LEVELS DO NOT EXPECT A
GREAT AMOUNT OF COVERAGE THUS THE CHANCE OF A TERMINAL ACTUALLY
BEING AFFECTED IS SMALL. WSW-W WINDS THIS MORNING SHOULD BECOME SW
BY AFTERNOON...EXCEPT SSW-SW IN THE WAKE OF THE SEA BREEZE
BOUNDARY. VFR/SW WINDS EXPECTED AFTER 00Z.
EXTENDED OUTLOOK...SCATTERED SHOWERS/TSTMS EXPECTED THURSDAY THROUGH
SATURDAY...MAINLY IN THE AFTERNOON AND EARLY EVENING HOURS...WITH
BRIEF PERIODS OF SUB-VFR CONDITIONS POSSIBLE. SUNDAY WILL BE DRIER
AS A COLD FRONT FINALLY DROPS SOUTHWARD THROUGH THE CAROLINAS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS 10 AM WEDNESDAY...THE WESTERN EXTENSION OF THE BERMUDA HIGH
WILL EXTEND AS FAR WEST AS FLORIDA TODAY AND TONIGHT. A COLD FRONT
DROPPING SOUTH ACROSS THE MID-ATLANTIC STATES WILL REMAIN NORTH OF
THE CAROLINAS TONIGHT...BUT THE PRESSURE TROUGH ASSOCIATED WITH
THE FRONT WILL HELP TO VEER OUR WINDS A LITTLE MORE WESTERLY THAN
WE SAW YESTERDAY. THIS WILL ACT COUNTER TO THE SEABREEZE...
RESULTING IN A SEABREEZE CIRCULATION WEAKER THAN WE SAW YESTERDAY.
THIS STILL MEANS NEAR-SHORE WINDS INCREASING TO A SOLID 15-18
KNOTS THIS AFTERNOON...WHILE WINDS FARTHER OFFSHORE WILL REMAIN IN
THE 10-15 KNOT RANGE. SCATTERED THUNDERSTORMS FIRING UP IN THE
HEAT OF THE AFTERNOON ALONG THE SEABREEZE FRONT MAY AFFECT THE
NEAR-SHORE WATERS BUT SHOULD HAVE A TOUGHER TIME SURVIVING
OFFSHORE.
SEAS ARE CURRENTLY AROUND 3 FEET...EXCEPT 3-4 FT NORTH AND EAST OF
CAPE FEAR. SEA HEIGHTS SHOULD REMAIN STEADY OR PERHAPS FALL BY A
FOOT THROUGH TONIGHT.
SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...HIGH PRESSURE CENTERED WELL OFFSHORE WILL
CONTINUE TO EXTEND WEST TOWARDS THE WATERS INTO THURSDAY...BEFORE
GRADUALLY BEING SHUNTED SOUTH BY A SLOWLY DROPPING COLD FRONT.
UNCERTAIN INTO JUST HOW FAR SOUTH THE FRONT WILL DROP DURING THE
PERIOD...BUT EXPECT NORTHERLY WINDS TO DEVELOP ACROSS THE NC
WATERS ON THURSDAY...WITH WEAK SW WINDS PERSISTING OVER THE SC
WATERS. SEAS WILL BE GENERALLY 2-4 FT AND A MORE CONFUSED
SPECTRUM WITH THE FRONT ON THURSDAY.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 300 PM TUESDAY...THE MAIN FOCUS FOR THE MARINE COMMUNITY
WILL BE THE WIND SHIFT ASSOCIATED WITH THE FRONT THAT OCCURS LATE
FRIDAY INTO EARLY SATURDAY. THE STRONGER OF THE WINDS WILL BE WELL
BEHIND THE FRONT ITSELF ASSOCIATED WITH NE SURGES. FOR
FRIDAY...LETHARGIC WINDS OF TEN KNOTS OR LESS WILL CONTINUE. FOR
LATER SATURDAY WINDS INCREASE TO 10-15 KNOTS. THERE MAY BE SEVERAL
HOURS OF WINDS NEAR 15 KNOTS SUSTAINED ACROSS THE OUTER WATERS
WHICH WOULD CERTAINLY IMPACT THE SEAS. SIGNIFICANT SEAS WILL BUILD
FROM 1-2 FEET FRIDAY INTO EARLY SATURDAY TO 3-4 FOR THE REMAINDER
OF THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MJC
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...MRR
MARINE...TRA/JDW
RADAR...SHK
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
748 AM EDT WED MAY 28 2014
.SYNOPSIS...
WARM AND HUMID WEATHER CONDITIONS ARE EXPECTED TODAY AND TOMORROW
WITH SCATTERED AFTERNOON AND EARLY EVENING THUNDERSTORMS. A COLD
FRONT WILL SLOWLY SINK SOUTH ACROSS THE CAROLINAS THURSDAY INTO
FRIDAY. HIGH PRESSURE WILL BUILD FROM THE NORTH OVER THE
WEEKEND...BRINGING DRIER AND SLIGHTLY COOLER CONDITIONS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM WEDNESDAY...EARLY MORNING CONVECTION IS FINALLY CLEAR
OF THE COAST AND DRY CONDITIONS SHOULD PREVAIL THE REMAINDER OF THE
MORNING. OUR LOCAL MESONET PRODUCT SHOWS OVER AN INCH OF RAIN FELL
IN PORTIONS OF SOUTHERN BRUNSWICK COUNTY OVERNIGHT. 0.30 INCHES WAS
RECORDED IN WILMINGTON...THE FIRST MEASURABLE RAIN HERE IN ALMOST
TWO WEEKS!
AT THE SURFACE THE WESTERN EXTENSION OF BERMUDA HIGH PRESSURE
EXTENDS AS FAR WEST AS FLORIDA...WITH SOUTH WINDS VEERING
SOUTHWESTERLY AT THE LATITUDE OF THE CAROLINAS. THIS IS BRINGING A
WARM AND QUITE HUMID AIRMASS NORTHWARD WITH PRECIPITABLE WATER
VALUES NEAR 1.8 INCHES CURRENTLY. A WEAK RIDGE AXIS ALOFT IS
PROBABLY A FUNCTION OF MID AND UPPER LEVEL FLOW SHAPED BY A CUTOFF
LOW ACROSS LOUISIANA. NUMEROUS TINY PERTURBATIONS IN THE UPPER FLOW
WERE RESPONSIBLE FOR WAVES OF CONVECTION IN THE MODERATELY UNSTABLE
AIRMASS ACROSS THE SOUTHEAST YESTERDAY. MODELS AGREE THAT ONE
TRACKABLE DISTURBANCE WILL APPROACH THE EASTERN CAROLINAS LATE THIS
AFTERNOON...PROBABLY ACCOMPANIED BY SCATTERED SHOWERS AND
THUNDERSTORMS. AVAILABLE SURFACE BOUNDARIES TO HELP FOCUS CONVECTION
INCLUDE THE SEABREEZE...THE PIEDMONT TROUGH...AND DIFFERENTIAL
HEATING BOUNDARIES IN THE SAND HILLS AND ALONG THE EDGE OF OUTFLOW
LAID DOWN BY THE EARLY MORNING STORMS IN SE NORTH CAROLINA.
FOR HIGH TEMPERATURES AN INTERESTING NEGATIVE BIAS HAS ARISEN IN
OPERATIONAL MOS GUIDANCE FROM BOTH THE GFS AND NAM OVER THE PAST
SEVERAL DAYS. HERE ARE SOME STATS FROM OUR LOCAL VERIFICATION PROGRAM:
GFS MOS BIAS NAM MOS BIAS
1 DAY 2 DAY 5 DAY 1 DAY 2 DAY 5 DAY
ILM -1 -2 -2 -2 -3 -2
FLO -2 -3 -2 -5 -4 -3
CRE 0 0 -1 -2 -1 -1
MYR +1 +1 0 0 +1 +1
LBT -4 -3 -2 -7 -6 -4
IT IS INTERESTING THAT AWAY FROM THE TWO MYRTLE BEACH STATIONS
(CRE AND MYR) MOS HAS PRODUCED CONSISTENTLY TOO-COOL OUTPUT.
USING THIS BIAS INFORMATION AND COMPARING FORECAST 850 MB TEMPS
DAY TO DAY IT APPEARS WE SHOULD HAVE HIGH TEMPERATURES IN THE
LOWER 90S FOR MOST AREAS AWAY FROM THE BEACHES TODAY.
THE WEAK UPPER DISTURBANCE SHOULD PUSH OFFSHORE DURING THE EARLY
EVENING...TAKING THE BETTER SHOWER/T-STORM CHANCES WITH IT. GIVEN
THE LARGE ELEVATED INSTABILITY LINGERING OVERNIGHT AND THE
POTENTIAL FOR MORE SUBTLE UPPER DISTURBANCES APPROACHING FROM THE
WEST I WILL MAINTAIN A 20 POP OVERNIGHT FOR ADDITIONAL
SHOWERS/T-STORMS. LOWS SHOULD FALL INTO THE UPPER 60S TO LOWER
70S...WARMEST AT THE BEACHES.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...WARM AND CONVECTIVELY-ACTIVE WEATHER WILL
CONTINUE THROUGH THE SHORT TERM AS THIS SUMMER LIKE PATTERN REMAINS
OVER THE AREA. CLOSED 500MB LOW PRESSURE WILL DRIFT SOUTHEAST ALONG
THE GULF COAST THU...WITH A LARGE RIDGE BUILDING ATOP THIS
FEATURE. LOCALLY...THE AREA REMAINS PINCHED BETWEEN THE CLOSED LOW
NEAR THE GULF...AND AN EXPANSIVE TROUGH NEAR NEW ENGLAND. BY
THURSDAY HEIGHTS BEGIN TO CRASH AS THE NEW ENGLAND TROUGH PUSHES
SOUTH...DRIVING A WEAK COLD FRONT INTO THE AREA. HIGHS IN THE
MID/UPR 80S ACROSS THE CWA. LOWS BOTH NIGHTS WILL REMAIN
ELEVATED...AROUND 70 AT THE COAST AND UPR 60S INLAND.
MORE WIDESPREAD TSTMS LIKELY THURSDAY AS THE FRONT DROPS
SOUTH...SERVING AS AN ADDITIONAL FOCUS FOR STORMS. SPC HAS A SEE
TEXT ACROSS THE AREA FOR THURSDAY...BUT ATTM SEE ONLY LIMITED
SEVERE RISK WITH MLCAPES LESS THAN 1000 J/KG AND FORECAST
SOUNDINGS WHICH SUGGEST A LOT OF PRE-FRONTAL CLOUD COVER. EITHER
WAY...EXPECT QUITE A FEW SHOWERS/STORMS ON THE RADAR MOSAIC ON
THURSDAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...THE MID LEVEL PATTERN REMAINS ESSENTIALLY
UNCHANGED WITH THE LATEST SUITE OF GUIDANCE. INITIALLY A REX BLOCK
WILL BE THE MAIN FEATURE OVER THE CENTRAL U.S. WITH A TROUGH OF
LOW PRESSURE ALONG THE EAST COAST. AT THE SURFACE...HIGH PRESSURE
WILL BUILD IN FROM THE NORTH WITH DRIER CONDITIONS. PRECIPITABLE
WATERS WILL DROP FROM CURRENT APPROXIMATE VALUES OF 1.80 INCHES TO
THREE QUARTERS OF AN INCH OR LESS. MUCH LIKE WE SAW THIS
WEEKEND...A REFRESHING AIRMASS WILL BE NOTICEABLE BUT THE
TRANSITION WILL BE A LITTLE SLOWER. HAVE MAINTAINED THE MOSTLY
DIURNALLY DRIVEN POPS FOR FRIDAY AND SATURDAY WITH THE REMAINDER
OF THE PERIOD DRY. TEMPERATURE TRENDS ARE OF COURSE A LITTLE LOWER
IN TIME WITH THE AIRMASS CHANGE BUT LOWS REMAIN MOSTLY IN THE 60S
WITH HIGHS IN THE 80S.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 12Z...RADAR INDICATES SHOWERS AND THUNDERSTORMS JUST OFFSHORE
OF KILM WITH ACTIVITY TRENDING FURTHER OFFSHORE. MVFR BR HAS
DEVELOPED IN THE MOIST HUMID AIRMASS AT KLBT.
VFR EXPECTED ALL TERMINALS SHORTLY AFTER 12Z. IN THE WAKE OF THE
CONVECTION CURRENTLY MOVING OFFSHORE DO NOT EXPECT ANY RE-DEVELOPMENT
UNTIL AFTER 18Z. IN AGREEMENT WITH THE HRRR THAT ACTIVITY THAT
DEVELOPS WILL BE FOCUSED AROUND AN OLD OUTFLOW BOUNDARY/SEA BREEZE
BOUNDARY NEAR KMYR/KCRE. SOME OF THIS ACTIVITY COULD REACH AS FAR
W AS KFLO/KLBT. DUE TO DRIER AIR IN THE MID LEVELS DO NOT EXPECT A
GREAT AMOUNT OF COVERAGE THUS THE CHANCE OF A TERMINAL ACTUALLY
BEING AFFECTED IS SMALL. WSW-W WINDS THIS MORNING SHOULD BECOME SW
BY AFTERNOON...EXCEPT SSW-SW IN THE WAKE OF THE SEA BREEZE
BOUNDARY. VFR/SW WINDS EXPECTED AFTER 00Z.
EXTENDED OUTLOOK...SCATTERED SHOWERS/TSTMS EXPECTED THURSDAY THROUGH
SATURDAY...MAINLY IN THE AFTERNOON AND EARLY EVENING HOURS...WITH
BRIEF PERIODS OF SUB-VFR CONDITIONS POSSIBLE. SUNDAY WILL BE DRIER
AS A COLD FRONT FINALLY DROPS SOUTHWARD THROUGH THE CAROLINAS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS 645 AM WEDNESDAY...THE WESTERN EXTENSION OF THE BERMUDA HIGH
WILL EXTEND AS FAR WEST AS FLORIDA TODAY AND TONIGHT. A COLD FRONT
DROPPING SOUTH ACROSS THE MID-ATLANTIC STATES WILL REMAIN NORTH OF
THE CAROLINAS TONIGHT...BUT THE PRESSURE TROUGH ASSOCIATED WITH
THE FRONT WILL HELP TO VEER OUR WINDS A LITTLE MORE WESTERLY THAN
WE SAW YESTERDAY. THIS WILL ACT COUNTER TO THE SEABREEZE...
RESULTING IN A SEABREEZE CIRCULATION WEAKER THAN WE SAW YESTERDAY.
THIS STILL MEANS NEAR-SHORE WINDS INCREASING TO A SOLID 15-18 KNOTS
THIS AFTERNOON...WHILE WINDS FARTHER OFFSHORE WILL REMAIN IN THE
10-15 KNOT RANGE. SCATTERED THUNDERSTORMS FIRING UP IN THE HEAT OF
THE AFTERNOON ALONG THE SEABREEZE FRONT MAY AFFECT THE NEAR-SHORE
WATERS BUT SHOULD HAVE A TOUGHER TIME SURVIVING OFFSHORE.
SEAS ARE CURRENTLY AROUND 3 FEET...EXCEPT 3-4 FT NORTH AND EAST OF
CAPE FEAR. SEA HEIGHTS SHOULD REMAIN STEADY OR PERHAPS FALL BY A
FOOT THROUGH TONIGHT.
SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...HIGH PRESSURE CENTERED WELL OFFSHORE WILL
CONTINUE TO EXTEND WEST TOWARDS THE WATERS INTO THURSDAY...BEFORE
GRADUALLY BEING SHUNTED SOUTH BY A SLOWLY DROPPING COLD FRONT.
UNCERTAIN INTO JUST HOW FAR SOUTH THE FRONT WILL DROP DURING THE
PERIOD...BUT EXPECT NORTHERLY WINDS TO DEVELOP ACROSS THE NC
WATERS ON THURSDAY...WITH WEAK SW WINDS PERSISTING OVER THE SC
WATERS. SEAS WILL BE GENERALLY 2-4 FT AND A MORE CONFUSED
SPECTRUM WITH THE FRONT ON THURSDAY.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 300 PM TUESDAY...THE MAIN FOCUS FOR THE MARINE COMMUNITY
WILL BE THE WIND SHIFT ASSOCIATED WITH THE FRONT THAT OCCURS LATE
FRIDAY INTO EARLY SATURDAY. THE STRONGER OF THE WINDS WILL BE WELL
BEHIND THE FRONT ITSELF ASSOCIATED WITH NE SURGES. FOR
FRIDAY...LETHARGIC WINDS OF TEN KNOTS OR LESS WILL CONTINUE. FOR
LATER SATURDAY WINDS INCREASE TO 10-15 KNOTS. THERE MAY BE SEVERAL
HOURS OF WINDS NEAR 15 KNOTS SUSTAINED ACROSS THE OUTER WATERS
WHICH WOULD CERTAINLY IMPACT THE SEAS. SIGNIFICANT SEAS WILL BUILD
FROM 1-2 FEET FRIDAY INTO EARLY SATURDAY TO 3-4 FOR THE REMAINDER
OF THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TRA
NEAR TERM...TRA
SHORT TERM...RGZ
LONG TERM...SHK
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
945 PM CDT THU MAY 29 2014
.UPDATE...
ISSUED AT 945 PM CDT THU MAY 29 2014
WILL ALLOW SEVERE THUNDERSTORM WATCH TO EXPIRE AS THE LAST FEW
STRONG/SEVERE STORMS HAVE WEAKENED. OTHERWISE MADE SOME ADDITIONAL
ADJUSTMENTS TO DECREASE POPS FARTHER EAST WHERE MODELS ARE INDICATING
LESS ACTIVITY...ESPECIALLY SOUTHEAST. COLD FRONT CONTINUES TO PUSH
SLOWLY EASTWARD WITH ONGOING CONVECTION OCCURRING BEHIND FRONT.
WINDS HAVE SHIFTED TO NW AT KMOT AT 0130Z AND FRONT IS NEARING
KBIS.
UPDATE ISSUED AT 658 PM CDT THU MAY 29 2014
CANCELLED WIND ADVISORY AS WINDS HAVE DIMINISHED BELOW ADVISORY
LIMITS. TRIMMED WESTERN-MOST COUNTIES FROM SEVERE THUNDERSTORM
WATCH...ALTHOUGH SOME POST FRONTAL DEVELOPMENT OCCURING ACROSS
EASTERN MCKENZIE SOUTHWARD INTO BILLINGS COUNTY WHERE LESS CAPE IS
AVAILABLE BUT STRONGER SHEAR IS IN PLACE. ADJUSTED POPS TO ACCOUNT
FOR LATEST TRENDS AND FOLLOWED HRRR WHICH SEEMED TO HANDLE
CONVECTION ADEQUATELY.
UPDATE ISSUED AT 428 PM CDT THU MAY 29 2014
SEVERE THUNDERSTORM WATCH IN EFFECT UNTIL 03Z FOR MUCH OF CENTRAL
AND WESTERN ND. CELLS BEGINNING TO DEVELOP ACROSS SOUTHWEST ND ALONG
COLD FRONT THAT IS SLOWLY MOVING EASTWARD. SPC MESO ANALYSIS PAGE
CONTINUES TO SHOW ABUNDANT INSTABILITY WITH CAPE OF 2000-3000 J/KG
ALONG AND AHEAD OF THE FRONT ALTHOUGH BEST SHEAR LAGS INSTABILITY
AXIS SOMEWHAT. EXPECTING TO BE ENOUGH OVERLAP OF SHEAR/INSTABILITY
TO SUPPORT MAINLY WIND/HAIL THREAT WITH STORMS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 230 PM CDT THU MAY 29 2014
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE THUNDERSTORMS
DEVELOPING THIS AFTERNOON/EARLY EVENING...CONTINUING AND SLOWLY
MOVING EAST TONIGHT INTO FRIDAY. A FEW SEVERE STORMS WILL BE
POSSIBLE. DETAILS BELOW.
CURRENTLY...UPPER LEVEL RIDGE AXIS ACROSS THE EASTERN DAKOTAS WITH
A STRONG S/WV TROUGH/CLOSED LOW LIFTING NORTHEAST INTO WESTERN
SASKATCHEWAN. THIS PUTS SOUTHWESTERLY FLOW ALOFT ACROSS THE
MONTANA ROCKIES AND WESTERN DAKOTAS. AT THE SURFACE... TROUGH OF
LOW PRESSURE JUST NOW CROSSING THE MONTANA/NORTH DAKOTA BORDER
WITH WINDS SHIFTING TO WESTERLY AT SIDNEY AND BAKER MONTANA. WINDS
HAVE REMAINED RATHER GUSTY EAST OF THE TROUGH ACROSS CENTRAL NORTH
DAKOTA WHERE GUSTS HAVE RANGED FROM 40 TO JUST OVER 50 MPH FROM
MORTON AND BURLEIGH COUNTIES NORTH AND NORTHEAST INTO NORTH
CENTRAL PORTIONS OF THE STATE. WILL MAINTAIN THE WIND ADVISORY AS
IS...ISSUED ABOUT AN HOUR OR TWO AGO THROUGH THE AFTERNOON HOURS.
MODELS IN GOOD AGREEMENT LIFTING THE STRONGER MID LEVEL WINDS INTO
CANADA BY 00Z...AS WELL AS RELAXING THE PRESSURE GRADIENT WITH
TIME.
HIGH RESOLUTION/SHORT TERM MODELS STILL IN GREAT AGREEMENT THAT
THE SFC TROUGH AXIS/COLD FRONTAL BOUNDARY WILL BE THE FOCUS FOR
CONVECTION MID TO LATE THIS AFTERNOON/EARLY EVENING AS THE MID
LEVEL CAPPING INVERSION ERODES WITH THE APPROACH OF AN UPPER
LEVEL SPEED MAX LIFTING NORTH AND EAST ACROSS MONTANA. INITIAL
DEVELOPMENT STILL A BIT UNCERTAIN...BUT MODELS IN GENERAL
AGREEMENT THUNDERSTORMS DEVELOPING ACROSS WESTERN SOUTH DAKOTA
FIRST PERHAPS OVER THE BLACK HILLS BY 20-21Z...THEN
NORTH/NORTHEAST ALONG THE FRONTAL BOUNDARY THEREAFTER.
THUNDERSTORMS THEN CONTINUE TO DEVELOP/MOVE NORTHEAST ALONG THE
BOUNDARY TONIGHT...WITH STORM COVERAGE INCREASING SLOWLY EAST
WITH THE FRONTAL MOVEMENT.
THE LATEST SPC DAY 1 OUTLOOK NOW HAS A SLIGHT RISK AREA ALONG A
NARROW AXIS ALONG THE FRONT...INCLUDING SOUTHWEST AND CENTRAL
PORTIONS OF NORTH DAKOTA...MAINLY DURING THE DAYLIGHT HOURS WITH
THE SEVERE THREAT DIMINISHING WITH DARK. MLCAPE VALUES ARE RISING
INTO THE 1500 TO 2500 J/KG RANGE NEAR THE BOUNDARY WITH EFFECTIVE
SHEAR OF 25 TO 30 KTS ALONG THE BOUNDARY. BETTER AND MORE
SUPPORTIVE SHEAR RESIDES WEST OF THE FRONT. WILL MENTION THE
POSSIBILITY OF SEVERE WEATHER IN THE HAZARDOUS WEATHER
OUTLOOK...ALTHOUGH SHOULD NOTE THE BEST CAPE WILL BE DISPLACED
FROM THE BEST SHEAR. STORM MOVEMENT SHOULD BE ROBUST WITH MEAN
STORM MOTION 30-40 KTS TO THE NORTHEAST. HOWEVER...WITH THE SLOW
EASTWARD MOVEMENT OF THE FRONT...AND STORMS EXPECTED TO REDEVELOP
ALONG THE FRONT...TRAINING THUNDERSTORMS WILL BE POSSIBILITY
ENHANCING THE POTENTIAL FOR HEAVY RAINFALL.
SFC TROUGH SLOWLY MOVES EAST FRIDAY...BECOMING QUASI-STATIONARY
OVER THE SOUTH CENTRAL EAST INTO THE JAMES AND RED RIVER VALLEY
REGIONS. THUS ANOTHER ROUND OF STRONG TO SEVERE STORMS WITH HEAVY
RAIN LIKELY ALONG TO AHEAD OF THE SFC BOUNDARY. WILL MAINTAIN A
DRY FORECAST ACROSS THE NORTHWEST QUARTER OF ND FRIDAY WITH HIGH
PRESSURE AND A STABLE AIRMASS DEVELOPING SOUTH AND EAST FROM
CANADA IN THE WAKE OF THE TROUGH.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 230 PM CDT THU MAY 29 2014
AN ACTIVE AND WET PATTERN IS STILL IN STORE ACROSS WESTERN AND
CENTRAL NORTH DAKOTA IN THE LONG TERM PERIOD.
FRIDAY EVENING...A NEARLY STATIONARY SURFACE FRONTAL BOUNDARY IS
FORECAST TO EXTEND FROM NORTHWESTERN MINNESOTA ACROSS SOUTHEASTERN
NORTH DAKOTA - INCLUDING THE JAMES RIVER VALLEY - AND INTO CENTRAL
SOUTH DAKOTA. THERE SHOULD BE ONGOING SHOWERS AND THUNDERSTORMS FROM
THE DAYTIME FRIDAY PERIOD. THIS SHOULD CONTINUE A PERIOD OF HEAVY
RAIN FRIDAY NIGHT INTO SATURDAY MORNING IN THE JAMES RIVER BASIN
EXTENDING WESTWARD INTO SOUTH CENTRAL NORTH DAKOTA IN THE SOUTHERN
MISSOURI VALLEY OF NORTH DAKOTA...SOUTH OF LAKE SAKAKAWEA.
AT UPPER LEVELS...A SEMI-PERMANENT TROUGH OVER THE ROCKIES WILL KEEP
A SOUTHWESTERLY FLOW ALOFT OVER NORTH DAKOTA. A SERIES OF UPPER
LEVEL ENERGY IMPULSES MOVING NORTHEASTWARD THROUGH THE FLOW FRIDAY
THROUGH SATURDAY MORNING WILL ENHANCE THE PRECIPITATION ALONG THE
SURFACE BOUNDARY.
THERE APPEARS TO BE A BREAK IN THE UPPER LEVEL ENERGY IMPULSES
SATURDAY LATE MORNING/EARLY AFTERNOON...BUT A REINFORCEMENT OF
IMPULSES ARRIVES SATURDAY AFTERNOON IN THE WEST...AND CONTINUES
THROUGH SUNDAY NIGHT.
HEAVY RAIN IS LOOKING LIKELY FROM BISMARCK TO CARRINGTON AND SOUTH
FRIDAY THROUGH THE SUNDAY NIGHT TIME FRAME.
THE MODELS DIFFER ON THE CHARACTER OF THE UPPER LEVEL ENERGY -
WHETHER CONTINUED TROUGHING OR A CLOSED LOW OVER THE STATE - BUT
REGARDLESS THE CHANCE OF THUNDERSTORMS CONTINUES INTO EARLY NEXT
WEEK. THE MODELS DIFFER ON TIMING OF UPPER LEVEL IMPULSES BY
EARLY/MID WEEK NEXT WEEK...SO KEPT THE MODEL CONSENSUS WITH ISOLATED
TO SCATTERED SHOWERS AND THUNDERSTORMS THROUGH MID-WEEK.
BEST CHANCES OF RAIN IN THE LONG TERM IS FRIDAY NIGHT THROUGH SUNDAY
NIGHT...BUT CHANCES CONTINUE IN EACH PERIOD OF THE FORECAST THROUGH
NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 658 PM CDT THU MAY 29 2014
SHOWERS AND THUNDERSTORMS CONTINUE NEAR COLD FRONT THAT IS SLOWLY
MOVING EASTWARD ACROSS THE STATE. WINDS WILL TURN WEST/NORTHWEST
BEHIND THE FRONT. MAINTAINED VCSH/VCTS FOR FRIDAY KBIS AND KJMS
WHERE THE FRONT WILL CONTINUE TO FOCUS PRECIPITATION.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JNS
SHORT TERM...NH
LONG TERM...JV
AVIATION...JNS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
658 PM CDT THU MAY 29 2014
.UPDATE...
ISSUED AT 658 PM CDT THU MAY 29 2014
CANCELLED WIND ADVISORY AS WINDS HAVE DIMINISHED BELOW ADVISORY
LIMITS. TRIMMED WESTERN-MOST COUNTIES FROM SEVERE THUNDERSTORM
WATCH...ALTHOUGH SOME POST FRONTAL DEVELOPMENT OCCURING ACROSS
EASTERN MCKENZIE SOUTHWARD INTO BILLINGS COUNTY WHERE LESS CAPE IS
AVAILABLE BUT STRONGER SHEAR IS IN PLACE. ADJUSTED POPS TO ACCOUNT
FOR LATEST TRENDS AND FOLLOWED HRRR WHICH SEEMED TO HANDLE
CONVECTION ADEQUATELY.
UPDATE ISSUED AT 428 PM CDT THU MAY 29 2014
SEVERE THUNDERSTORM WATCH IN EFFECT UNTIL 03Z FOR MUCH OF CENTRAL
AND WESTERN ND. CELLS BEGINNING TO DEVELOP ACROSS SOUTHWEST ND ALONG
COLD FRONT THAT IS SLOWLY MOVING EASTWARD. SPC MESO ANALYSIS PAGE
CONTINUES TO SHOW ABUNDANT INSTABILITY WITH CAPE OF 2000-3000 J/KG
ALONG AND AHEAD OF THE FRONT ALTHOUGH BEST SHEAR LAGS INSTABILITY
AXIS SOMEWHAT. EXPECTING TO BE ENOUGH OVERLAP OF SHEAR/INSTABILITY
TO SUPPORT MAINLY WIND/HAIL THREAT WITH STORMS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 230 PM CDT THU MAY 29 2014
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE THUNDERSTORMS
DEVELOPING THIS AFTERNOON/EARLY EVENING...CONTINUING AND SLOWLY
MOVING EAST TONIGHT INTO FRIDAY. A FEW SEVERE STORMS WILL BE
POSSIBLE. DETAILS BELOW.
CURRENTLY...UPPER LEVEL RIDGE AXIS ACROSS THE EASTERN DAKOTAS WITH
A STRONG S/WV TROUGH/CLOSED LOW LIFTING NORTHEAST INTO WESTERN
SASKATCHEWAN. THIS PUTS SOUTHWESTERLY FLOW ALOFT ACROSS THE
MONTANA ROCKIES AND WESTERN DAKOTAS. AT THE SURFACE... TROUGH OF
LOW PRESSURE JUST NOW CROSSING THE MONTANA/NORTH DAKOTA BORDER
WITH WINDS SHIFTING TO WESTERLY AT SIDNEY AND BAKER MONTANA. WINDS
HAVE REMAINED RATHER GUSTY EAST OF THE TROUGH ACROSS CENTRAL NORTH
DAKOTA WHERE GUSTS HAVE RANGED FROM 40 TO JUST OVER 50 MPH FROM
MORTON AND BURLEIGH COUNTIES NORTH AND NORTHEAST INTO NORTH
CENTRAL PORTIONS OF THE STATE. WILL MAINTAIN THE WIND ADVISORY AS
IS...ISSUED ABOUT AN HOUR OR TWO AGO THROUGH THE AFTERNOON HOURS.
MODELS IN GOOD AGREEMENT LIFTING THE STRONGER MID LEVEL WINDS INTO
CANADA BY 00Z...AS WELL AS RELAXING THE PRESSURE GRADIENT WITH
TIME.
HIGH RESOLUTION/SHORT TERM MODELS STILL IN GREAT AGREEMENT THAT
THE SFC TROUGH AXIS/COLD FRONTAL BOUNDARY WILL BE THE FOCUS FOR
CONVECTION MID TO LATE THIS AFTERNOON/EARLY EVENING AS THE MID
LEVEL CAPPING INVERSION ERODES WITH THE APPROACH OF AN UPPER
LEVEL SPEED MAX LIFTING NORTH AND EAST ACROSS MONTANA. INITIAL
DEVELOPMENT STILL A BIT UNCERTAIN...BUT MODELS IN GENERAL
AGREEMENT THUNDERSTORMS DEVELOPING ACROSS WESTERN SOUTH DAKOTA
FIRST PERHAPS OVER THE BLACK HILLS BY 20-21Z...THEN
NORTH/NORTHEAST ALONG THE FRONTAL BOUNDARY THEREAFTER.
THUNDERSTORMS THEN CONTINUE TO DEVELOP/MOVE NORTHEAST ALONG THE
BOUNDARY TONIGHT...WITH STORM COVERAGE INCREASING SLOWLY EAST
WITH THE FRONTAL MOVEMENT.
THE LATEST SPC DAY 1 OUTLOOK NOW HAS A SLIGHT RISK AREA ALONG A
NARROW AXIS ALONG THE FRONT...INCLUDING SOUTHWEST AND CENTRAL
PORTIONS OF NORTH DAKOTA...MAINLY DURING THE DAYLIGHT HOURS WITH
THE SEVERE THREAT DIMINISHING WITH DARK. MLCAPE VALUES ARE RISING
INTO THE 1500 TO 2500 J/KG RANGE NEAR THE BOUNDARY WITH EFFECTIVE
SHEAR OF 25 TO 30 KTS ALONG THE BOUNDARY. BETTER AND MORE
SUPPORTIVE SHEAR RESIDES WEST OF THE FRONT. WILL MENTION THE
POSSIBILITY OF SEVERE WEATHER IN THE HAZARDOUS WEATHER
OUTLOOK...ALTHOUGH SHOULD NOTE THE BEST CAPE WILL BE DISPLACED
FROM THE BEST SHEAR. STORM MOVEMENT SHOULD BE ROBUST WITH MEAN
STORM MOTION 30-40 KTS TO THE NORTHEAST. HOWEVER...WITH THE SLOW
EASTWARD MOVEMENT OF THE FRONT...AND STORMS EXPECTED TO REDEVELOP
ALONG THE FRONT...TRAINING THUNDERSTORMS WILL BE POSSIBILITY
ENHANCING THE POTENTIAL FOR HEAVY RAINFALL.
SFC TROUGH SLOWLY MOVES EAST FRIDAY...BECOMING QUASI-STATIONARY
OVER THE SOUTH CENTRAL EAST INTO THE JAMES AND RED RIVER VALLEY
REGIONS. THUS ANOTHER ROUND OF STRONG TO SEVERE STORMS WITH HEAVY
RAIN LIKELY ALONG TO AHEAD OF THE SFC BOUNDARY. WILL MAINTAIN A
DRY FORECAST ACROSS THE NORTHWEST QUARTER OF ND FRIDAY WITH HIGH
PRESSURE AND A STABLE AIRMASS DEVELOPING SOUTH AND EAST FROM
CANADA IN THE WAKE OF THE TROUGH.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 230 PM CDT THU MAY 29 2014
AN ACTIVE AND WET PATTERN IS STILL IN STORE ACROSS WESTERN AND
CENTRAL NORTH DAKOTA IN THE LONG TERM PERIOD.
FRIDAY EVENING...A NEARLY STATIONARY SURFACE FRONTAL BOUNDARY IS
FORECAST TO EXTEND FROM NORTHWESTERN MINNESOTA ACROSS SOUTHEASTERN
NORTH DAKOTA - INCLUDING THE JAMES RIVER VALLEY - AND INTO CENTRAL
SOUTH DAKOTA. THERE SHOULD BE ONGOING SHOWERS AND THUNDERSTORMS FROM
THE DAYTIME FRIDAY PERIOD. THIS SHOULD CONTINUE A PERIOD OF HEAVY
RAIN FRIDAY NIGHT INTO SATURDAY MORNING IN THE JAMES RIVER BASIN
EXTENDING WESTWARD INTO SOUTH CENTRAL NORTH DAKOTA IN THE SOUTHERN
MISSOURI VALLEY OF NORTH DAKOTA...SOUTH OF LAKE SAKAKAWEA.
AT UPPER LEVELS...A SEMI-PERMANENT TROUGH OVER THE ROCKIES WILL KEEP
A SOUTHWESTERLY FLOW ALOFT OVER NORTH DAKOTA. A SERIES OF UPPER
LEVEL ENERGY IMPULSES MOVING NORTHEASTWARD THROUGH THE FLOW FRIDAY
THROUGH SATURDAY MORNING WILL ENHANCE THE PRECIPITATION ALONG THE
SURFACE BOUNDARY.
THERE APPEARS TO BE A BREAK IN THE UPPER LEVEL ENERGY IMPULSES
SATURDAY LATE MORNING/EARLY AFTERNOON...BUT A REINFORCEMENT OF
IMPULSES ARRIVES SATURDAY AFTERNOON IN THE WEST...AND CONTINUES
THROUGH SUNDAY NIGHT.
HEAVY RAIN IS LOOKING LIKELY FROM BISMARCK TO CARRINGTON AND SOUTH
FRIDAY THROUGH THE SUNDAY NIGHT TIME FRAME.
THE MODELS DIFFER ON THE CHARACTER OF THE UPPER LEVEL ENERGY -
WHETHER CONTINUED TROUGHING OR A CLOSED LOW OVER THE STATE - BUT
REGARDLESS THE CHANCE OF THUNDERSTORMS CONTINUES INTO EARLY NEXT
WEEK. THE MODELS DIFFER ON TIMING OF UPPER LEVEL IMPULSES BY
EARLY/MID WEEK NEXT WEEK...SO KEPT THE MODEL CONSENSUS WITH ISOLATED
TO SCATTERED SHOWERS AND THUNDERSTORMS THROUGH MID-WEEK.
BEST CHANCES OF RAIN IN THE LONG TERM IS FRIDAY NIGHT THROUGH SUNDAY
NIGHT...BUT CHANCES CONTINUE IN EACH PERIOD OF THE FORECAST THROUGH
NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 658 PM CDT THU MAY 29 2014
SHOWERS AND THUNDERSTORMS CONTINUE NEAR COLD FRONT THAT IS SLOWLY
MOVING EASTWARD ACROSS THE STATE. WINDS WILL TURN WEST/NORTHWEST
BEHIND THE FRONT. MAINTAINED VCSH/VCTS FOR FRIDAY KBIS AND KJMS
WHERE THE FRONT WILL CONTINUE TO FOCUS PRECIPITATION.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JNS
SHORT TERM...NH
LONG TERM...JV
AVIATION...JNS
AREA FORECAST DISCUSSION
NWS PORTLAND OR
911 PM PDT TUE MAY 27 2014
.SYNOPSIS...AN UPPER LEVEL LOW OFF THE COAST WILL SWING ONSHORE
TUESDAY NIGHT AND WEDNESDAY FOR INCREASING SHOWERS WITH POSSIBLY A
FEW THUNDERSTORMS. A SURFACE THERMAL TROUGH WILL PROVIDE WARMER
TEMPERATURES LATE IN THE WEEK AS A BROAD UPPER TROUGH HOLDS OVER THE
AREA...AND MAINTAINS A THREAT FOR AFTERNOON MOUNTAIN SHOWERS AND
THUNDERSTORMS.
&&
.UPDATE...VISIBLE AND INFRARED SATELLITE IMAGERY REVEAL AN UPPER
LEVEL LOW PRESSURE SPINNING OFF THE OREGON COAST. DOPPLER RADAR
GENERALLY SHOWS SHOWERS WEAKENING OVER THE INTERIOR OF THE CWA WITH
THE LOSS OF DAYTIME HEATING.
THE CAP THAT HELD BACK SHOWERS FROM INTENSIFYING THIS AFTERNOON BROKE
JUST PRIOR TO SUNSET THIS EVENING WITH A COUPLE CELLS OVER THE
SOUTHEASTERN SUBURBS OF PORTLAND AND ANOTHER CELL NEAR MT RAINIER
SHOOTING UP INTO THE -30C TO -35C RANGE PER INFRARED SATELLITE
IMAGERY. ONE LIGHTNING NETWORK DETECTED LIGHTNING EAST OF OREGON
CITY...BUT OTHER NETWORKS DID NOT DETECT ANY LIGHTNING IN THE CWA
THIS EVENING.
MODELS ALL GENERALLY AGREE THE COLD POOL ALOFT...APPROXIMATELY -28C
AT 500MB...WILL MOVE DIRECTLY OVERHEAD TONIGHT. THE MOST INTENSE
SHOWERS OVER THE OCEAN THIS EVENING CURRENTLY RESIDE ON THE SOUTHERN
SIDE OF THE LOW PRESSURE SO THE MOST INTENSE SHOWER MAY BE MORE
CONCENTRATED TOWARDS THE COAST AND LANE COUNTY. ALSO...CANNOT RULE
OUT A CLAP OR TWO OF THUNDER ALONG THE COAST AS SHOWERS GET A BOOST
BY THE COAST RANGE AND TAP INTO THE DEEP INSTABILITY PRESENT.
WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS SHOULD GET GOING IN A
HURRY WEDNESDAY MORNING. MODEL SOUNDINGS CONTINUE TO SHOW A
SUBSIDENCE INVERSION LOWERING DURING THE AFTERNOON AND EARLY EVENING
HOURS...WHICH SHOULD BRING AN END TO THE THUNDERSTORM THREAT FROM
WEST TO EAST ACROSS THE AREA DURING THIS TIME. /NEUMAN
THE REST OF THE FORECAST REMAINS ON TRACK...SEE PREVIOUS DISCUSSION
BELOW...
.SHORT TERM...TUESDAY AFTERNOON THROUGH FRIDAY...FORECAST CONCERNS
REVOLVE AROUND CONVECTIVE EVOLUTION THROUGH WEDNESDAY. AREA OF SLOW
MOVING SHOWERS IN THE COAST RANGE WHERE THEY WERE GENERALLY PROGGED
TO FORM TODAY...AND EVEN SOME ON THE WEST SLOPES OF THE CASCADES.
SPC MESOANALYSIS BASED ON THE RAP 40KM MODEL SUGGESTS THE CAP IS
JUST ABOUT ERODED OFFSHORE AND IS ERODING INLAND...AND THIS IS
CONFIRMED BY ACARS/AMDAR SOUNDINGS OUT OF KPDX WITH THE MID LEVEL
WARM NOSE AROUND 750 MB GETTING LESS PRONOUNCED...BUT STILL THERE.
WE ARE STARTING TO SEE THE UPPER TROUGH PUSH CLOSER TO SHORE...AND
UPPER LEVEL TEMPERATURES ARE DROPPING WHICH IS AIDING THE CAP
EROSION...BUT THIS PROCESS IS TAKING SOME TIME INLAND GIVEN THE
BROKEN CLOUD COVER. LATER THIS AFTERNOON AND EVENING THE UPPER
TROUGH AXIS DRIFTS CLOSER TO SHORE AND THE CAP EASES A BIT MORE.
MODEL INSTABILITY PARAMETERS STILL LOOK REALLY WEAK...BUT VARIOUS
CONVECTIVE ALLOWING MODELS DRIFT THE CURRENT AREA OF SHOWERS WITH
SOME 50DBZ ECHOES THROUGH MUCH OF THE NORTHERN HALF OF THE
AREA...MAINLY ALONG THE COAST RANGE AND WILLAPA HILLS THEN SPREADING
INLAND TO NEAR THE FOOTHILLS THIS EVENING. ENOUGH INSTABILITY MAY
EXIST TO POP AN ISOLATED T-STORM OR TWO. INSTABILITY PARAMETERS
WEAKEN THROUGH THE NIGHT INLAND AND SHOULD JUST BE SHOWERS BY TIME
THEY GET TO THE CASCADES. PRECIPITABLE WATER VALUES ARE NOT VERY
HIGH...BUT THE SHOWERS AND STORMS ARE SOMEWHAT SLOW MOVING WHICH MAY
LEAD TO OCCASIONAL MODERATE RAINFALL.
TONIGHT...THESE SHOWERS WILL CONTINUE EAST INTO THE CASCADES. MORE
WIDESPREAD SHOWER DEVELOPMENT IS EXPECTED ALONG THE COAST TONIGHT
AND SPREADING INLAND OVERNIGHT INTO WEDNESDAY AS THE UPPER LOW MOVES
ONSHORE. THE UPPER LOW SHOULD REACH THE COAST BY MIDNIGHT...BE OVER
THE VALLEY BY DAYBREAK. THE CORE OF THE UPPER LOW WILL ALREADY BE
EAST OF THE CASCADES IN THE AFTERNOON. THUNDERSTORMS ARE POSSIBLE AT
THE COAST OVERNIGHT...AND INLAND AS EARLY AS TOMORROW MORNING....BUT
EITHER WAY WEDNESDAY LOOKS TO BE COOL AND SHOWERY. FREEZING LEVELS
LOWER TO ABOUT 5K FEET...AND THUS SOME SMALL HAIL IS POSSIBLE IN THE
HEAVIER SHOWERS. SNOW LEVELS WILL DROP TO APPROXIMATELY 4500 FEET
AND A SLUSHY INCH OF SNOW WILL BE POSSIBLE OVER SANTIAM AND
WILLAMETTE PASSES AND POSSIBLY AT GOVERNMENT CAMP EARLY WEDNESDAY
MORNING. ANY SNOW IMPACTS WILL BE SHORT LIVED DUE TO THE STRONG
SOLAR INPUT THIS TIME OF YEAR.MODELS SHOW GREATER INSTABILITY
WEDNESDAY WITH MIXED LAYER CAPE AROUND 300 J/KG...ENOUGH TO SUPPORT
THE SLIGHT CHANCE FOR THUNDERSTORM MENTION.
THE UPPER LOW PULLS EAST BUT ITS TROUGH AXIS WILL LINGER OVER THE
AREA INTO THURSDAY...THUS EXPECT CLOUDS TO LINGER AROUND WEDNESDAY
NIGHT INTO EARLY THURSDAY WITH SHOWERS GENERALLY DECREASING FROM
SOUTH TO NORTH...HANGING ON THE LONGEST ALONG AND NORTH OF THE
COLUMBIA RIVER THURSDAY. A SURFACE THERMAL TROUGH OVER NORTHERN CA
WILL EXPAND NORTHWARD INTO SOUTHERN OREGON THURSDAY AFTERNOON AND
TEMPERATURES WILL REBOUND CLOSER TO NORMAL.
FRIDAY THE AIRMASS CONTINUES TO WARM AS A SECONDARY UPPER LOW DIGS
OFF THE CALIFORNIA COAST. A THETA-E RIDGE BUILDS ALONG THE CASCADES
IN THE SW FLOW ALOFT...AND THERE IS A CHANCE FOR A SHOWER OR T-STORM
IN THESE AREAS LATER IN THE DAY. MOST AREAS ELSEWHERE REMAIN DRY AND
SIGNIFICANTLY WARMER...WITH UPPER 70S TO LOW 80S FOR THE INTERIOR
LOWLANDS. KMD
.LONG TERM...FRIDAY NIGHT THROUGH MONDAY...AN UPPER LEVEL TROUGH
WILL REMAIN OVER THE PAC NW FROM FRI NIGHT THROUGH NEXT WEEKEND.
SOME OF THE FCST MODEL ENSEMBLES ARE INDICATING THAT THE TROUGH
COULD DEVELOP INTO A CLOSED LOW ON SATURDAY. WILL KEEP A CHANCE FOR
SHOWERS AND THUNDERSTORMS OVER THE CASCADES LATE FRI THROUGH SUNDAY
NIGHT...MAINLY DURING THE AFTERNOON AND EVENING HOURS.
ELSEWHERE...EXPECT DRY AND WARM CONDITIONS TO REMAIN IN CONTROL.
MAINLY ONSHORE FLOW OVER THE EXTENDED PERIOD SHOULD MEAN OVERNIGHT
AND MORNING CLOUDS AT THE COAST...POSSIBLY PUSHING INTO PARTS OF THE
INTERIOR VALLEYS. INLAND VALLEY HIGHS WILL LIKELY REACH WELL INTO
THE 70S OVER THE WEEKEND...RUNNING ABOUT 5 DEGREES ABOVE SEASONAL
NORMALS. THE UPPER LEVEL TROUGH WILL FINALLY PUSH EAST OF THE REGION
EARLY NEXT WEEK...BUT ANOTHER WEEK SHORTWAVE MAY PUSH IN ON MONDAY.
PYLE
&&
.AVIATION...VFR PREVAILING FOR THROUGH WED. SHOWERS ARE DECREASING
THIS EVENING...BUT WITH AN UPPER TROUGH OVER MOVING ASHORE...SHOWERS
ARE NOT EXPECTED TO END. SHOWERS WILL LIKELY INCREASE WED MORNING.
ISOLATED THUNDERSTORMS ARE POSSIBLE NEAR THE COAST OVERNIGHT AND
INLAND AS WELL ON WED.
KPDX AND APPROACHES...VFR PREVAILING THROUGH WED. ISOLATED SHOWERS
CONTINUE IN THE AREA OVERNIGHT. THUNDERSTORM THREAT WILL BE LOW
OVERNIGHT...BUT INCREASE WED LATER WED MORNING THROUGH THE
AFTERNOON.
&&
.MARINE...03Z SURFACE ANALYSIS HAS WEAK SFC LOW ABOUT 40 NM SW OF
KAST AND CONTINUES TO TRACK SOUTH. REMNANTS OF THE LOW FORECAST
TO MOVE ASHORE NEAR NEWPORT BETWEEN BY 12Z WED. SURFACE GRADIENTS
NOT ALL THAT IMPRESSIVE THROUGH TONIGHT...WITH WIND SPEEDS AT 15
KT OR LESS.
HIGH PRES DEVELOPS OVER THE WATERS LATE TONIGHT AND THEN SETTLES
OVER THE NE PAC THE REST OF THE WEEK. SURFACE THERMAL LOW PRES
FORMS ALONG THE N CALIFORNIA COAST WED AFTERNOON...AND THEN
SPREADS TO THE S OREGON COAST WED NIGHT AND THU. WIND SPEEDS
INCREASE INTO THE 15 TO 20 KT RANGE WED...WITH THE POTENTIAL FOR
25 KT GUSTS OVER THE S WATERS BEGINNING THU AFTERNOON. LITTLE
CHANGE IN THE OVERALL PATTERN FRI THROUGH THE WEEKEND.
SEAS GENERALLY 3 TO 5 FT THROUGH WED...THEN BUMPING UP INTO THE 5
TO 7 FT RANGE. THE STRONGER N WIND MIDWEEK AND BEYOND WILL CREATE
CHOPPY WIND DRIVEN SEAS...ESPECIALLY S OF CASCADE HEAD LATE IN THE
WEEK AND OVER THE WEEKEND. WEISHAAR.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1036 PM EDT THU MAY 29 2014
.SYNOPSIS...
CLOUDY AND COOL EASTERLY FLOW WILL PREVAIL ACROSS THE REGION TONIGHT.
A COLD FRONT WILL PUSH SOUTH ACROSS PENNSYLVANIA FRIDAY. HIGH
PRESSURE WILL BUILD IN FOR THE WEEKEND...BRINGING MOSTLY SUNNY AND
DRY WEATHER...BUT SLIGHTLY BELOW NORMAL TEMPERATURES.
&&
.NEAR TERM /THROUGH FRIDAY/...
SERLY FLOW AND SHALLOW LYR OF MOISTURE REMAINS ACROSS CENTRAL
PA LATE THIS EVENING...PRODUCING STRATUS AND PERHAPS SOME PATCHY
DRIZZLE OVR PARTS OF SOUTHERN PA...WHERE RAP 0-1KM RH STILL NR 100
PCT.
PRES GRADIENT/SERLY LL FLOW WILL WEAKEN CONSIDERABLY OVERNIGHT...LIKELY
CAUSING THE STRATUS TO BREAK UP A BIT...ESP OVR THE W MTNS.
HOWEVER...ANY CLEARING...COMBINED WITH A NEARLY CALM WIND...WILL
PROMOTE AREAS OF FOG. DEPENDING ON WHEN THE CLOUDS BREAK...SOME
OF THE FOG COULD BE DENSE OVR THE NW MTNS. DWPT DEPRESSIONS AT
02Z ALREADY VERY LOW.
CURRENT DWPTS SUGGEST OVERNIGHT LOWS WILL BE WITHIN A FEW DEGREES
OF 50F OVR THE ENTIRE AREA.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH 6 PM FRIDAY/...
HIGH PRESSURE WILL BEGIN TO BULGE DOWN OUT OF THE GREAT
LAKES FRIDAY...ULTIMATELY PUSHING A COLD FRONT THROUGH THE AREA
AND BRINGING AN END TO THE DREARY CONDITIONS OF TODAY. WHILE
SUMMER HEAT AND HIGH HEIGHTS ALOFT WILL BE LURKING NOT TOO VERY
FAR TO OUR WEST...WE WILL REMAIN ON THE OUTER PERIPHERY OF YET
ANOTHER UPPER LOW/TROUGH DROPPING THROUGH THE NEW ENGLAND COASTAL
WATERS. THE NAM/GFS AGREE IN BRINGING A WEAK SHORTWAVE AROUND THE
WESTERN EDGE OF THIS FLOW...RESULTING IN THE STEEPENING OF MID
LEVEL LAPSE RATES AND THE POTENTIAL FOR SOME SHOWERS FRIDAY
AFTERNOON.
DESPITE LIMITED LLVL MOISTURE WITH DEWPOINTS TRENDING LOWER INTO
THE WEEKEND...THERE SHOULD BE ENOUGH INSTABILITY AND LIFT TO
GENERATE SCATTERED LATE DAY SHOWERS OVER THE ERN/NERN 1/3 OF THE
FORECAST AREA.
HIGH TEMPS FRIDAY WILL REBOUND BACK INTO THE LOWER AND MID 70S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
THE LATEST MODEL AND ENSEMBLE DATA CYCLE MAINTAINS FAIRLY GOOD
AGREEMENT ON THE LARGE SCALE PATTERN EVOLUTION THROUGH DAY 4/SUN
BEFORE NOTABLE DIFFERENCES START TO INTRODUCE UNCERTAINTY AND
LOWER CONFIDENCE IN THE FCST DETAILS INTO THE FIRST WEEK OF JUNE.
IN GENERAL...A COLD UPPER TROUGH WILL SHIFT EWD FROM NRN NEW
ENGLAND INTO THE NWRN ATLC WHILE A HIGH-LEVEL RIDGE FLATTENS AS IT
MIGRATES EWD FROM THE GREAT LAKES INTO THE NORTHEAST BY 12Z MON.
THE BULK OF THE UNCERTAINTY IS TIED TO A SHORTWAVE TROUGH LIFTING
ENEWD ACROSS THE N-CNTRL US TOWARD ONTARIO/QUEBEC DAY 5-8. THE
TRACK AND DEPTH OF THIS SHORTWAVE WILL INFLUENCE MVMT/SPEED OF SFC
LOW PRES MOVG EWD FROM THE UPPER MIDWEST INTO THE GREAT LAKES
WITH ITS ASSOCIATED WARM/COLD FRONTS PROVIDING A FOCUS FOR
CONVECTION.
A SEASONABLY WARM AND ABNORMALLY DRY/LOW HUMIDITY PERIOD IS
EXPECTED OVER THE WEEKEND...WITH BELOW NORMAL PWS SUPPORTING
A FEW CHILLY MORNINGS ACROSS THE NORTHERN TIER ZONES. SOME OF THE
USUALLY COLDER SPOTS IN THE N-CNTRL MTNS COULD DIP INTO THE UPPER
30S AND MAY EVEN EXPERIENCE A LATE-SEASON PATCHY FROST. THIS IS
NOT OUT OF THE QUESTION GIVEN THAT THE AVG DATE FOR THE LAST
FROST /MIN TEMP <=36F/ AT BRADFORD IS STILL ABOUT 2 WEEKS AWAY
--6/13-- GOING BACK TO 1957.
INCREASING WARMTH AND HUMIDITY SHOULD RETURN TO THE AREA NEXT
WEEK RISING 500MB HEIGHTS AND +1-2SD 850MB TEMPS ANOMALIES. THE
WARMING TREND MAY BE MODULATED SLIGHTLY BY CONVECTION...BUT THE
ODDS ARE STILL TILTED TOWARD ABOVE NORMAL READINGS. SPEAKING OF
CONVECTION...THERE SHOULD BE SEVERAL OPPORTUNITIES FOR PCPN...THE
1ST OF WHICH MAY BE IN THE FORM OF A MCS MON NGT-TUE FOLLOWED BY
PRE/FRONTAL SHWRS AND TSTMS THRU THE MIDDLE OF NEXT WEEK. HIGHEST
POPS ARE CENTERED ON TUE-WED BASED ON A CONSENSUS BLEND OF WPC
GUIDANCE AND GFS/EC BASED OPRNL+ENSEMBLE MOS DATA.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
MOIST SE FLOW BECOMES LIGHT AND THEN TRANSITIONS TO NORTHERLY
TOWARD SUNRISE. BUT ENTRENCHED WIDESPREAD MVFR/IFR CONDITIONS WILL
PERSIST...AND LIKELY BECOME LIFR/IFR...BEFORE GRADUALLY IMPROVING
FROM 13-15Z /PERSISTING THE LONGEST IN THE SOUTH/.
ON FRIDAY...N/NW FLOW OF DRIER AIR WILL DEVELOP AND BRING
IMPROVEMENT BY MID MORNING...WITH VFR BECOMING THE RULE FOR MUCH
OF THE DAY. THERE WILL BE A LOW CHANCE OF AFTERNOON SHOWERS AND
POSS A THUNDERSTORM BRINGING BRIEF REDUCTIONS OVER EASTERN AREAS.
OUTLOOK...
SAT-SUN...NO SIG WX.
MON...MAINLY VFR WITH SCATTERED SHOWERS AND THUNDERSTORMS.
TUE...AREAS OF MVFR/IFR WITH A COLD FRONT TRIGGERING SHOWERS AND
THUNDERSTORMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD/LA CORTE
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...STEINBUGL
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1025 PM EDT THU MAY 29 2014
.SYNOPSIS...
A BACKDOOR COLD FRONT WILL SLOWLY CROSS THE FORECAST AREA FROM THE
NORTHEAST THROUGH FRIDAY NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE
NORTHEAST THIS WEEKEND...AND MOVE OFFSHORE EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
1000 PM UPDATE...CONVECTION CONTINUES TO FIRE OVER MAINLY THE
PIEDMONT DUE TO ENHANCED LLVL CONVERGENCE...NOT ONLY DUE TO THE
BACKDOOR COLD FRONT BUT ALSO APPARENTLY AS MOIST SOUTHERLY FLOW
INTERCEPTS THE COLD POOL. WINDS HAVE LARGELY TURNED EAST AT THE SFC
ACRS THE NE HALF OF THE FA...BUT KGSP/TCLT VWP SHOWS S TO SE WINDS
IN THE 2-5 KFT AGL LAYER. SOME CELLS ARE ALSO DEVELOPING AS EXPECTED
IN THE VICINITY OF THE NRN BLUE RIDGE. HRRR CONTINUES TO BE THE BEST
NEAR TERM MODEL AND GENERALLY SUPPORTS A SLOW DECLINE IN ACTIVITY
THRU THE NIGHT...WITH OCNL REDEVELOPMENT AS THE FRONT COMES IN. I
REVISED POPS AGAIN TO HIGHLIGHT THE DIMINISHING ACTIVITY IN OUR
EAST...BUT STILL CHC POPS EVERYWHERE WITH CONTINUED DEVELOPMENT
LIKELY ALBEIT NOT WIDE COVERAGE.
FLOOD WARNINGS/ADVISORIES REMAIN IN EFFECT ALONG THE I-77 CORRIDOR.
WHILE THE CHARLOTTE AREA PRODUCTS MIGHT BE ABLE TO EXPIRE ON
TIME...CELLS ARE NOW MOVING SWD INTO OUR NRN TIER OF ZONES WHICH
WILL PROLONG THE THREAT IN THE NRN GROUP.
AS OF 300 PM...OVER THE NEXT 24 HOURS...THE MAIN CONCERN WILL BE THE
FRONTAL ZONE DROPPING DOWN FROM THE NORTH. A SURFACE REFLECTION
ALREADY SHOWS IN THE CAPE ANALYSIS NUDGING INTO THE NW
PIEDMONT...WITH LOW CLOUDINESS AND STABLE AIR IN N CENTRAL NC. A
SHORT WAVE DROPPING DOWN INTO THE UPPER TROF OFF THE EAST COAST WILL
CONTINUE TO DRIVE THIS BOUNDARY FARTHER SOUTH AND EAST THIS EVENING.
THE MODELS DO NOT REALLY SHOW MUCH IN THE WAY OF LOW LEVEL FORCING
BUT THIS COULD BE MASKED BY THE DIURNAL CONVERGENCE TOWARD THE MTNS.
IT STANDS TO REASON THAT THE BOUNDARY MAY PROVIDE THE FOCUS FOR
CONVECTION WELL INTO THE NIGHTTIME HOURS. THERE IS SOME CONCERN FOR
FLASH FLOOD POTENTIAL OVER THE NC BLUE RIDGE AND FOOTHILLS IF THE
BOUNDARY MOVES FAR ENOUGH SOUTH TO DEVELOP A LOW LEVEL EASTERLY FLOW
THAT COULD ANCHOR STORMS NEAR THE BLUE RIDGE...BUT NOT ENOUGH
CONCERN TO ENTERTAIN A WATCH. EXPECT A DIURNAL REDUCTION IN STORM
COVERAGE AFTER MIDNIGHT IN SPITE OF THE BOUNDARY...SO SOME OF THE
LATEST SREF WAS BLENDED INTO THE POP. ON FRIDAY...SHOWERS AND STORMS
SHOULD DEVELOP YET AGAIN ACROSS THE ENTIRE FCST AREA...BUT WE MIGHT
BE COVERED WITH A LOW CLOUD CEILING BANKED UP AGAINST THE BLUE RIDGE
THAT WILL CUT DOWN ON THE POTENTIAL FOR SEVERE STORMS. TEMPS SHOULD
BE A BIT COOLER WITH THE ADDITIONAL CLOUD COVER AND EASTERLY FLOW
DEVELOPING.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AT 215 PM EDT THURSDAY...ON FRIDAY NIGHT AN UPPER RIDGE OVER THE
NORTHERN PLAINS WILL MOVE SOUTHEAST BETWEEN A CLOSED LOW OVER LA AND
AND UPPER TROUGH OFF THE EAST COAST...REACHING THE SOUTHERN
APPALACHIANS. THE RIDGE CENTER WILL MOVE OVER THE OH RIVER VALLEY ON
SATURDAY...AND OVER GA ON SUNDAY.
A BACK DOOR COLD FRONT WILL DRIFT VERY SLOWLY SOUTH ACROSS SC ON
FRIDAY NIGHT...AND ACROSS THE SAVANNAH RIVER VALLEY ON SATURDAY.
MODEL SOUNDINGS SHOW ELEVATED INSTABILITY VERY SLOWLY DECREASING
ALONG THE BOUNDARY ON FRIDAY NIGHT...AND INCREASING AGAIN ON
SATURDAY...MAINTAINING A THREAT OF CONVECTION AND HEAVY RAINFALL. ON
SATURDAY NIGHT THE FRONT MOVES SOUTHWEST OF OUR AREA...BUT LINGERING
LOW LEVEL MOISTURE AND AN EASTERLY UPSLOPE COMPONENT WILL SUPPORT A
CHANCE PRECIPITATION ALONG THE SOUTHERN BLUE RIDGE ESCARPMENT. DRIER
AIR WORKING INTO THE AREA FROM THE NW ON SUNDAY WILL REDUCE THE
CHANCE OF PRECIPITATION...BUT THE MODEL SUGGEST THAT MOISTURE BANKED
UP AGAINST THE SOUTHERN BLUE RIDGE WILL PERSIST...AND SMALL POPS
WILL BE CARRIED THERE AGAIN.
TEMPERATURES WILL RUN ABOVE NORMAL WITH RISING HEIGHTS ALOFT...UNTIL
COOLER AIR BEHIND THE FRONT WORKS INTO THE AREA ON SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AT 215 PM EDT THURSDAY...ON MONDAY AN UPPER RIDGE WILL EXTEND FROM
FL TO THE EASTERN GREAT LAKES...WHILE A CLOSED UPPER LOW WILL BE
OVER THE WESTERN ATLANTIC AND AN UPPER TROUGH WILL BE OVER THE WEST
COAST. THE UPPER RIDGE PROGRESS TO THE EAST COAST BY TUESDAY...WHILE
A SHORTWAVE MOVES ACROSS THE GREAT LAKES AREA. THE PATTERN
DEAMPLIFIES BY WEDNESDAY...LEADING TO A LARGELY ZONAL FLOW ACROSS
THE NATION...AND WEAK FLAT RIDGING OVER THE SOUTHEAST...A PATTERN
THAT PERSISTS INTO THURSDAY.
SURFACE HIGH PRESSURE WILL BE CENTERED NEAR THE COASTAL VA AND NC ON
MONDAY...AND ALTHOUGH GULF INFLOW ON THE WEST SIDE OF THIS RIDGE
WILL BE FOCUSED OVER THE MS...TN AND OH VALLEYS...THE MODELS
INDICATE MOISTURE OVER THE SOUTHERN APPALACHIANS...WITH UPSLOPE FLOW
AND INCREASING INSTABILITY SUPPORTING DIURNALLY DRIVEN CONVECTION.
AS THE SURFACE HIGH DRIFTS SE AND OFFSHORE FROM TUESDAY THROUGH
THURSDAY...GULF INFLOW WEAKENS...BUT SPREADS EAST...COVERING NE GA
AND THE WESTERN CAROLINAS. UPSLOPE FLOW INTO ELEVATED TERRAIN WILL
BE RATHER WEAK...BUT ENOUGH TO SUPPORT THE BEST CHANCES OF
CONVECTION REMAINING ALONG THE BLUE RIDGE...EVEN AS CONVECTIVE
CHANCES INCREASE TO THE EAST.
TEMPERATURES WILL RISE FROM NEAR NORMAL VALUES...TO ABOVE NORMAL...
EVEN AS HEIGHTS FALL ALOFT...AS COOL NE FLOW VEERS TO THE SW...
AND WARM ADVECTION ENSUES.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
AT KCLT...CLUSTER OF SHRA WILL REMAIN OVER THE FIELD THRU LATE
EVENING...IN CONVERGENCE ZONE WHERE BACKDOOR COLD FRONT IS MEETING
MOIST SOUTHERLY FLOW ALOFT. MOST GUIDANCE MEMBERS INDICATE SOME KIND
OF LOW STRATUS DEVELOPING BEHIND THE FRONT AS IT TRIES TO PUSH THRU
THE AREA...HENCE MVFR CIG ARRIVES AFTER MIDNIGHT. FOG NOW A BIT MORE
LIKELY AT DAYBREAK DUE TO THE RAIN THIS EVENING...BUT WITH MIXED
SIGNALS FROM GUID I WILL KEEP IT MVFR. FRONT LINGERS IN THE AREA
FRIDAY...WHICH AGAIN BRINGS DECENT PRECIP CHANCES DUE TO DIURNAL
INSTABILITY AND ITS FOCUSING OF CONVECTION. THE WINDOW OF HIGHEST
CHANCES IS A BIT WIDER DUE TO THE PRESENCE OF THE FRONT. INCLUDED AN
MVFR PROB30 FOR THIS WINDOW. WINDS PREVAIL NE EXCEPT WHEN GUST
FRONTS FROM TSRA PASS THRU.
ELSEWHERE...OVERALL TRENDS SIMILAR TO KCLT. ELY WINDS WILL SPREAD
ACRS THE NC PIEDMONT AND UP TO THE BLUE RIDGE AS FRONT MOVES SWD
THRU THOSE REGIONS TONIGHT. MVFR CIGS...PERHAPS IFR ESP ALONG THE
BLUE RIDGE...WILL EVENTUALLY DEVELOP. SHRA/TSRA ARE LIKELY TO
CONTINUE ALONG THE FRONT WELL INTO THE EVENING. IFR FOG NOT OUT OF
THE QUESTION WHERE RAIN FELL...BUT CONFIDENCE LOW GIVEN THE LOW CIGS
LIKELY DEVELOPING FIRST. CHC-RANGE POPS WARRANT VC AND/OR PROB30
MENTION DURING THE DAY FRI.
OUTLOOK...ALTHOUGH GRADUAL DRYING WILL DEVELOP FROM THE NE OVER THE
WEEKEND INTO EARLY NEXT WEEK...CONTINUED BOUNDARY LAYER MOISTURE
WILL PRODUCE ISOLATED TO SCATTERED DIURNAL CONVECTION EACH
DAY...WITH MORNING RESTRICTIONS POSSIBLE.
CONFIDENCE TABLE...
02-08Z 08-14Z 14-20Z 20-02Z
KCLT HIGH 99% MED 75% HIGH 100% HIGH 100%
KGSP HIGH 88% HIGH 94% HIGH 100% HIGH 100%
KAVL MED 77% MED 72% HIGH 97% HIGH 81%
KHKY HIGH 82% MED 79% HIGH 83% HIGH 100%
KGMU HIGH 91% MED 77% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 94% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JAT
NEAR TERM...PM/WIMBERLEY
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
811 PM EDT THU MAY 29 2014
.SYNOPSIS...
A BACKDOOR COLD FRONT WILL SLOWLY CROSS THE FORECAST AREA FROM THE
NORTHEAST THROUGH FRIDAY NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE
NORTHEAST THIS WEEKEND...AND MOVE OFFSHORE EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH FRIDAY/...
730 PM UPDATE...CURRENT EXPANSE OF VIGOROUS CONVECTION ALONG A LINE
FROM BLACK MOUNTAIN ESEWD TO FORT MILL SEEMS TO REFLECT THE
CONVERGENCE ALONG THE BACK DOOR FRONT. STILL HARD TO PICK OUT THE
FRONTAL POSITION FROM OBS...BUT IN GENERAL SFC WINDS ARE NELY NORTH
OF THIS LINE. RAP AND HRRR SEEM TO BE DOING A DECENT JOB HANDLING
THE LLVL WIND FIELD AND THE HRRR RUNS HAVE BEEN RATHER GOOD WRT
CONVECTIVE COVERAGE THIS AFTN. LATEST RUN CONTINUES TO LIGHT UP THE
CONVERGENCE ZONE UNTIL AFTER MIDNIGHT. ENOUGH ELEVATED CAPE IS
PRESENT TO THINK THIS IS STILL POSSIBLE. REVISED THE OVERNIGHT FCST
TRENDS TO REFLECT A SOLUTION THAT IS MORE LIKE THE
RAP/HRRR...HIGHLIGHTING THE AREA ALONG THE BOUNDARY FOR BEST
POPS...AND SUPPORTING CONTINUED ELY FLOW TO ITS NORTH. FOR THE
LATTER REASON THE BLUE RIDGE APPEARS TO BE AT A LITTLE HIGHER FLASH
FLOOD THREAT WITH ANCHORING POSSIBLE...AS NOTED BY PREV SHIFTS.
DENSE FOG IS A POSSIBILITY MAINLY IN THE MTN VALLEYS...WITH LOW
STRATUS LOOKING MORE LIKELY OVER THE PIEDMONT.
AS OF 300 PM...OVER THE NEXT 24 HOURS...THE MAIN CONCERN WILL BE THE
FRONTAL ZONE DROPPING DOWN FROM THE NORTH. A SURFACE REFLECTION
ALREADY SHOWS IN THE CAPE ANALYSIS NUDGING INTO THE NW
PIEDMONT...WITH LOW CLOUDINESS AND STABLE AIR IN N CENTRAL NC. A
SHORT WAVE DROPPING DOWN INTO THE UPPER TROF OFF THE EAST COAST WILL
CONTINUE TO DRIVE THIS BOUNDARY FARTHER SOUTH AND EAST THIS EVENING.
THE MODELS DO NOT REALLY SHOW MUCH IN THE WAY OF LOW LEVEL FORCING
BUT THIS COULD BE MASKED BY THE DIURNAL CONVERGENCE TOWARD THE MTNS.
IT STANDS TO REASON THAT THE BOUNDARY MAY PROVIDE THE FOCUS FOR
CONVECTION WELL INTO THE NIGHTTIME HOURS. THERE IS SOME CONCERN FOR
FLASH FLOOD POTENTIAL OVER THE NC BLUE RIDGE AND FOOTHILLS IF THE
BOUNDARY MOVES FAR ENOUGH SOUTH TO DEVELOP A LOW LEVEL EASTERLY FLOW
THAT COULD ANCHOR STORMS NEAR THE BLUE RIDGE...BUT NOT ENOUGH
CONCERN TO ENTERTAIN A WATCH. EXPECT A DIURNAL REDUCTION IN STORM
COVERAGE AFTER MIDNIGHT IN SPITE OF THE BOUNDARY...SO SOME OF THE
LATEST SREF WAS BLENDED INTO THE POP. ON FRIDAY...SHOWERS AND STORMS
SHOULD DEVELOP YET AGAIN ACROSS THE ENTIRE FCST AREA...BUT WE MIGHT
BE COVERED WITH A LOW CLOUD CEILING BANKED UP AGAINST THE BLUE RIDGE
THAT WILL CUT DOWN ON THE POTENTIAL FOR SEVERE STORMS. TEMPS SHOULD
BE A BIT COOLER WITH THE ADDITIONAL CLOUD COVER AND EASTERLY FLOW
DEVELOPING.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AT 215 PM EDT THURSDAY...ON FRIDAY NIGHT AN UPPER RIDGE OVER THE
NORTHERN PLAINS WILL MOVE SOUTHEAST BETWEEN A CLOSED LOW OVER LA AND
AND UPPER TROUGH OFF THE EAST COAST...REACHING THE SOUTHERN
APPALACHIANS. THE RIDGE CENTER WILL MOVE OVER THE OH RIVER VALLEY ON
SATURDAY...AND OVER GA ON SUNDAY.
A BACK DOOR COLD FRONT WILL DRIFT VERY SLOWLY SOUTH ACROSS SC ON
FRIDAY NIGHT...AND ACROSS THE SAVANNAH RIVER VALLEY ON SATURDAY.
MODEL SOUNDINGS SHOW ELEVATED INSTABILITY VERY SLOWLY DECREASING
ALONG THE BOUNDARY ON FRIDAY NIGHT...AND INCREASING AGAIN ON
SATURDAY...MAINTAINING A THREAT OF CONVECTION AND HEAVY RAINFALL. ON
SATURDAY NIGHT THE FRONT MOVES SOUTHWEST OF OUR AREA...BUT LINGERING
LOW LEVEL MOISTURE AND AN EASTERLY UPSLOPE COMPONENT WILL SUPPORT A
CHANCE PRECIPITATION ALONG THE SOUTHERN BLUE RIDGE ESCARPMENT. DRIER
AIR WORKING INTO THE AREA FROM THE NW ON SUNDAY WILL REDUCE THE
CHANCE OF PRECIPITATION...BUT THE MODEL SUGGEST THAT MOISTURE BANKED
UP AGAINST THE SOUTHERN BLUE RIDGE WILL PERSIST...AND SMALL POPS
WILL BE CARRIED THERE AGAIN.
TEMPERATURES WILL RUN ABOVE NORMAL WITH RISING HEIGHTS ALOFT...UNTIL
COOLER AIR BEHIND THE FRONT WORKS INTO THE AREA ON SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AT 215 PM EDT THURSDAY...ON MONDAY AN UPPER RIDGE WILL EXTEND FROM
FL TO THE EASTERN GREAT LAKES...WHILE A CLOSED UPPER LOW WILL BE
OVER THE WESTERN ATLANTIC AND AN UPPER TROUGH WILL BE OVER THE WEST
COAST. THE UPPER RIDGE PROGRESS TO THE EAST COAST BY TUESDAY...WHILE
A SHORTWAVE MOVES ACROSS THE GREAT LAKES AREA. THE PATTERN
DEAMPLIFIES BY WEDNESDAY...LEADING TO A LARGELY ZONAL FLOW ACROSS
THE NATION...AND WEAK FLAT RIDGING OVER THE SOUTHEAST...A PATTERN
THAT PERSISTS INTO THURSDAY.
SURFACE HIGH PRESSURE WILL BE CENTERED NEAR THE COASTAL VA AND NC ON
MONDAY...AND ALTHOUGH GULF INFLOW ON THE WEST SIDE OF THIS RIDGE
WILL BE FOCUSED OVER THE MS...TN AND OH VALLEYS...THE MODELS
INDICATE MOISTURE OVER THE SOUTHERN APPALACHIANS...WITH UPSLOPE FLOW
AND INCREASING INSTABILITY SUPPORTING DIURNALLY DRIVEN CONVECTION.
AS THE SURFACE HIGH DRIFTS SE AND OFFSHORE FROM TUESDAY THROUGH
THURSDAY...GULF INFLOW WEAKENS...BUT SPREADS EAST...COVERING NE GA
AND THE WESTERN CAROLINAS. UPSLOPE FLOW INTO ELEVATED TERRAIN WILL
BE RATHER WEAK...BUT ENOUGH TO SUPPORT THE BEST CHANCES OF
CONVECTION REMAINING ALONG THE BLUE RIDGE...EVEN AS CONVECTIVE
CHANCES INCREASE TO THE EAST.
TEMPERATURES WILL RISE FROM NEAR NORMAL VALUES...TO ABOVE NORMAL...
EVEN AS HEIGHTS FALL ALOFT...AS COOL NE FLOW VEERS TO THE SW...
AND WARM ADVECTION ENSUES.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AT KCLT...CLUSTER OF TSRA WILL REMAIN NEARLY STATIONARY AT AND INVOF
THE FIELD EARLY THIS EVENING...IN CONVERGENCE ZONE WHERE BACKDOOR
COLD FRONT IS MEETING MOIST SOUTHERLY FLOW. HEAVY DOWNPOURS WILL
LIKELY BRING IFR VSBY. FRONT IS MOVING SWWD VERY SLOWLY THRU THE
PIEDMONT AND INSTABILITY WILL JUST HAVE TO BE DIMINISHED FOR THIS
ACTIVITY TO END. MOST GUIDANCE MEMBERS INDICATE SOME KIND OF LOW
STRATUS DEVELOPING BEHIND THE FRONT AS IT TRIES TO PUSH THRU THE
AREA...HENCE MVFR CIG ARRIVES AFTER MIDNIGHT. ANY HEAVY RAIN COULD
INCREASE FOG POTENTIAL THOUGH CONFIDENCE TOO LOW TO INCLUDE THIS.
FRONT LINGERS IN THE AREA FRIDAY AGAIN WITH SUGGESTIONS OF
INSTABILITY AND ASSOCIATED SHRA/TSRA CHANCES. THE WINDOW OF HIGHEST
CHANCES IS A BIT WIDER DUE TO THE PRESENCE OF THE FRONT. INCLUDED AN
MVFR PROB30 FOR THIS WINDOW. WINDS PREVAIL NE EXCEPT WHEN GUST
FRONTS FROM TSRA PASS THRU.
ELSEWHERE...OVERALL TRENDS SIMILAR TO KCLT. ELY WINDS WILL SPREAD
ACRS THE NC PIEDMONT AND UP TO THE BLUE RIDGE AS FRONT MOVES SWD
THRU THOSE REGIONS TONIGHT. MVFR CIGS...PERHAPS IFR ESP ALONG THE
BLUE RIDGE...WILL EVENTUALLY DEVELOP. SHRA/TSRA ARE LIKELY TO
CONTINUE ALONG THE FRONT WELL INTO THE EVENING. IFR FOG NOT OUT OF
THE QUESTION WHERE RAIN FELL...BUT CONFIDENCE LOW GIVEN THE LOW CIGS
LIKELY DEVELOPING FIRST. CHC-RANGE POPS WARRANT VC AND/OR PROB30
MENTION DURING THE DAY FRI.
OUTLOOK...ALTHOUGH GRADUAL DRYING WILL DEVELOP FROM THE NE OVER THE
WEEKEND INTO EARLY NEXT WEEK...CONTINUED BOUNDARY LAYER MOISTURE
WILL PRODUCE ISOLATED TO SCATTERED DIURNAL CONVECTION EACH
DAY...WITH MORNING RESTRICTIONS POSSIBLE.
CONFIDENCE TABLE...
00-06Z 06-12Z 12-18Z 18-24Z
KCLT HIGH 100% MED 78% HIGH 89% HIGH 100%
KGSP HIGH 91% HIGH 95% HIGH 95% HIGH 100%
KAVL HIGH 90% MED 72% HIGH 83% HIGH 88%
KHKY HIGH 88% HIGH 81% MED 72% HIGH 100%
KGMU HIGH 100% HIGH 83% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JAT
NEAR TERM...PM/WIMBERLEY
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
425 PM EDT WED MAY 28 2014
.SYNOPSIS...
BERMUDA HIGH PRESSURE LINGERS ACROSS THE REGION INTO TONIGHT. THEN A
BACKDOOR COLD FRONT WILL SAG SOUTHWARD INTO THE FORECAST AREA
THURSDAY...AND GRADUALLY SETTLE SOUTH OF THE AREA...AS HIGH PRESSURE
BUILDS IN FROM THE NORTH THIS WEEKEND.
&&
.NEAR TERM /THROUGH THURSDAY/...
415 PM UPDATE...NO SIGNIFICANT CHANGES AT THIS UPDATE. A FEW
CLUSTERS OF PULSEY CELLS HAVE BROKEN OUT ACRS THE MTNS/FOOTHILLS IN
VERY WEAKLY SHEARED PROFILE. MEAN FLOW WOULD TAKE INDIVIDUAL CELLS
ON AN EWD PATH AROUND 10 KT. PER DUAL POL ESTIMATES...THE CORES OF
THESE CELLS HAVE PRODUCED UPWARDS OF 2 INCHES OF RAIN IN LESS THAN
AN HOUR...WITH A FEW TENTHS ADDING UP NEARER THE FRINGES OF THE
CELLS. REVISED POP/QPF OVER THE NEXT COUPLE HOURS EXPECTING THESE
CLUSTERS TO SLOWLY PROPAGATE EASTWARD. THE LATEST ROUND OF SHORT
RANGE GUIDANCE STILL SUPPORTS THE GOING FCST OF GREATLY ISOLATED
CELLS LASTING THRU 01-02Z. HRRR SEEMS TO BE ON TRACK...EXPECTING THE
FOCUS TO MOVE EAST OF THE BLUE RIDGE WHERE THE CELLS ARE APPEARING
TO PROPAGATE.
AS OF 245 PM...LATEST MESOSCALE ANALYSIS CONTINUES TO SHOW VERY HIGH
DCAPE VALUES AND STEEP LOW LEVEL LAPSE RATES JUST ABOUT EVERYWHERE
OUTSIDE OF THE MTNS. STILL EXPECT BEST COVERAGE TO BE OVER THE MTNS
AND I-40 CORRIDOR WITH SLIGHTLY LOWER COVERAGE ELSEWHERE. THE
HIGHEST SVR POTENTIAL IS WHERE COVERAGE IS LESS...BUT THERE SHUD
STILL BE ENUF STORMS THIS AFTERNOON/EARLY EVENING FOR A HANDFUL OF
WARNINGS. EXPECT THE STORMS TO BE MAINLY DIURNAL...EVEN THO A BACK
DOOR COLD FRONT DROPS TOWARD THE AREA NEAR DAYBREAK. THERE MAY BE
ENUF FORCING OR DEVELOPING UPSLOPE FLOW FOR SOME LINGERING SHRA OVER
THE NC MTNS...BUT GUIDANCE KEEPS CHC RELATIVELY LOW. SHUD BE ANOTHER
ROUND OF PATCHY DENSE MTN VALLEY FOG AS CONVECTIVE DEBRIS THINS
OVERNIGHT. LOWS WILL BE AS MUCH AS 5 DEGREES BELOW NORMAL.
THE BACK DOOR COLD FRONT WILL PUSH INTO THE AREA THU BRINGING AN
INCREASE IN LOW LEVEL CONVERGENCE AND ELY UPSLOPE FLOW. EXPECT AN
EARLIER START TO CONVECTION AS DEEPER MOISTURE AND THE CONVERGENCE
AND UPSLOPE FLOW MOVE INTO THE AREA. COVERAGE SHOULD RAMP UP TO
LIKELY ACROSS THE MTNS BY NOON...THEN ACROSS THE REST OF NC AND THE
ERN UPSTATE DURING THE AFTERNOON. HIGH SCT COVERAGE SHUD DEVELOP
ACROSS THE WRN UPSTATE AND NE GA. THE ATMOS WILL REMAIN UNSTABLE
EVEN WHERE THE FRONT MOVES IN AS MID LEVEL LAPSE RATES REMAIN BETTER
THAN 6.5C/KM...WITH LOW END MODERATE INSTABILITY POSSIBLE...ESP OVER
THE SRN CWFA. HOWEVER...LOW LEVEL LAPSE RATES WILL BE MUCH LESS
STEEP AND DCAPE VALUES WILL BE LOWER THAN THE PAST FEW DAYS GIVEN
THE INCREASED MOISTURE. SHEAR WILL NOT BE PARTICULARLY STRONG EVEN
WITH THE FRONT MOVING IN AS THE CWFA WILL BE IN A WEAK FLOW REGION
BETWEEN AN UPPER LOW TO THE WEST AND A DEVELOPING TROF OVER THE NERN
US. STILL...GIVEN THE INSTABILITY...INCREASED LOW LEVEL FORCING...
AND SOME POTENTIAL FOR ORGANIZATION...ANOTHER DAY WITH A HANDFUL OF
SVR STORMS IS POSSIBLE. IN ADDITION...ISOLATED EXCESSIVE RAINFALL
COULD DEVELOP DUE TO THE INCREASED MOISTURE...SLOW MOVING STORMS AND
UPSLOPE FLOW. EVEN WITH THE FRONT MOVING IN...INCREASED CLOUDS AND
MOISTURE...THICKNESSES REMAIN HIGH. THEREFORE...HIGHS SHUD BE A
LITTLE ABOVE NORMAL.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AT 230 PM EDT WEDNESDAY...ON THURSDAY NIGHT AND UPPER TROUGH WILL BE
ALONG THE EAST COAST...WHILE A CLOSED LOW REMAINS OVER LA...AND AN
UPPER RIDGE WILL BE CENTERED OVER MN. THE UPPER RIDGE WILL MOVE SE
ON FRIDAY....EXTENDING TO THE SOUTHERN APPALACHIANS. BY SATURDAY THE
UPPER LOW WILL HAVE FILLED...WHILE THE UPPER RIDGE WILL HAVE MOVED
TO THE OH RIVER VALLEY...AND WILL EXTEND TO N FL.
A SLOW MOVING BACK DOOR COLD FRONT WILL MOVE S OVER THE CAROLINAS ON
THURSDAY NIGHT...AND WILL CROSS THE SAVANNAH RIVER VALLEY INTO GA ON
FRIDAY. THIS BOUNDARY WILL SERVE AS A FOCUSING MECHANISM FOR
PRECIPITATION AND CONVECTION...AS THE MODEL SHOW DEEP MOISTURE WITH
THIS FEATURE...AND VARYING DEGREES OF INSTABILITY...EVEN AT NIGHT
AND BEHIND THE BOUNDARY. THE SLOW MOVING NATURE OF THE FRONT COULD
SUPPORT HEAVY RAINFALL...AS THE MODELS SUGGEST THE POSSIBILITY OF
CELLS TRAINING FROM WEST TO EAST ALONG THE BOUNDARY.
DRYING FROM ALOFT BEHIND THE FRONT ON FRIDAY NIGHT AND SATURDAY WILL
BE LOW TO OCCUR...BUT WHEN COMBINED WITH DECREASING INSTABILITY...
SHOULD RESULT IN DECREASING PRECIPITATION RATES. THE BEST COVERAGE
WILL OCCUR ALONG THE SOUTHERN BLUE RIDGE...WHERE THE MODELS SUPPORT
LINGERING MOISTURE IN AN EASTERLY UPSLOPE FLOW COMPONENT.
TEMPERATURES WILL EXHIBIT A REDUCED DIURNAL RANGE DUE TO CLOUD COVER
AND MOISTURE...WITH MINIMUMS A BIT ABOVE NORMAL...AND MAXIMUMS A BIT
BELOW NORMAL.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AT 230 PM EDT WEDNESDAY...ON SUNDAY MORNING AN UPPER RIDGE WILL
EXTENDING FROM THE NE GULF OF MEXICO TO THE EASTERN GREAT
LAKES...WHILE A CLOSED WILL BE OFF THE COAST OF NEW ENGLAND...AND AN
UPPER TROUGH WILL BE OVER THE WESTERN USA. THE UPPER RIDGE
PROGRESSES LITTLE ON MONDAY AND TUESDAY...BUT DOES DEAMPLIFY...BY
WEDNESDAY A NEAR ZONAL FLOW EXISTS FROM THE S TI THE MID ATLANTIC.
HIGH PRESSURE WILL EXTEND ALONG THE EASTERN SEABOARD ON SUNDAY.
THIS AIR MASS WILL BE SOMEWHAT DRY FOR THIS TIME OF YEAR...BUT AN
EASTERLY FLOW COMPONENT ALONG THE SOUTHERN PORTION OF THE HIGH WILL
KEEP MOISTURE BANKED UP AGAINST THE SOUTHERN APPALACHIANS....WHERE
THE BEST CHANCE OF PRECIPITATION WILL EXIST...DESPITE LIMITED
INSTABILITY. BY MONDAY THE CENTER OF THE HIGH WILL BE OVER THE
CAROLINAS...WITH A WEAK UPSLOPE FLOW INTO THE BLUE RIDGE REMAINING.
ON TUESDAY AND WEDNESDAY THE HIGH WEAKENS FURTHER AND SETTLES
FARTHER SOUTH...AND LEE TROUGHING IS EXPECTED EAST OF THE BLUE
RIDGE. GULF INFLOW WILL REMAIN TO OUR WEST...BUT THE MOUNTAINS WILL
REMAIN THE BEST BET FOR CONVECTION DUE TO LINGERING MOISTURE AND
OROGRAPHIC EFFECTS.
TEMPERATURES INITIALLY WILL RUN BELOW NORMAL FOR THIS TIME OF
YEAR...RISING TO ABOVE NORMAL BY MID WEEK A THE INITIALLY COOL AIR
MASS MODERATES...DESPITE FALLING HEIGHTS ALOFT.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...THUNDERSTORMS EXPECTED AGAIN THIS AFTERNOON...SO AFTER
COLLABORATION...HAVE TEMPO FROM 21Z-24Z TO COVER. WSW WIND WILL
CONTINUE INTO THE EVENING. DEVELOPING BKN VFR CU SHUD SCATTER OUT
THIS EVENING THEN RETURN BY NOON. CALM WIND OVERNIGHT BECOMES LIGHT
NE AS BACK DOOR FRONT MOVES INTO THE AREA. ANY LOW CLOUDS ASSOCIATED
WITH THE FRONT WILL REMAIN WELL TO THE NORTH. EXPECT CONVECTION TO
BEGIN A LITTLE SOONER THU AS THE FRONT MOVES IN.
ELSEWHERE...CONVECTION DEVELOPING OVER THE MTNS WITH A CELL VERY
CLOSE TO KAVL. HAVE ADDED AN EARLY TEMPO THERE...WITH VCTS ALL AREAS
THRU THE AFTERNOON. W TO SW WINDS THIS AFTERNOON BECOME CALM
OVERNIGHT AND NW DURING THE DAY THU. DEVELOPING BKN VFR CU SCATTERS
OUT OVERNIGHT...WITH IFR VSBY AND CIGS AGAIN AT KAVL...WITH MVFR
VSBY KHKY/KAND. VFR RETURNS QUICKLY AFTER DAYBREAK WITH CONVECTION
DEVELOPING EARLIER AS A BACK DOOR FRONT MOVES IN. ANY LOW CLOUDS
WITH THE FRONT WILL REMAIN WELL NORTH OF THE AREA.
OUTLOOK...A BACKDOOR COLD FRONT WILL MOVE INTO THE AREA FROM THE N
ON THURSDAY AND SLOWLY SETTLE SOUTHWARD INTO THE EARLY WEEKEND.
MORNING FOG AND LOW CLOUDS ARE LIKELY EACH MORNING IN THE MOUNTAIN
VALLEYS AND ALSO AT FOOTHILL/PIEDMONT LOCATIONS WHERE HEAVIER RAIN
FALLS. SCATTERED DIURNAL THUNDERSTORMS WILL CONTINUE SUNDAY THROUGH
MONDAY.
CONFIDENCE TABLE...
20-02Z 02-08Z 08-14Z 14-20Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 91% LOW 52% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 91% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 86% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...RWH/WIMBERLEY
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...RWH
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1121 AM MDT WED MAY 28 2014
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 320 AM MDT WED MAY 28 2014
CURRENT SURFACE MAP SHOWS LOW PRESSURE MOVING THROUGH THE GREAT
BASIN WITH DIFFUSE STATIONARY FRONT ACROSS SOUTHERN MONTANA INTO
NORTHERN NORTH DAKOTA. SMALL AREA OF DIMINISHING CONVECTION
LOCATED NEAR THE BLACK HILLS.
FOR TODAY...UPPER TROF MOVES THROUGH THE PACIFIC NORTHWEST...WITH
RIDGE BUILDING ACROSS THE DAKOTAS. LARGE SCALE SUBSIDENCE ACROSS
THE DAKOTAS WITH Q-VECTOR DIVERGENCE. HIGH BOUNDARY LAYER MOISTURE
WILL RESULT IN MLCAPE AROUND 1500J/KG. WITH MLCIN AROUND 100
J/KG AND LACK OF FORCING...WILL MAINTAIN DRY FORECAST THROUGH THE
AFTERNOON. LATEST RUN OF HRRR SUGGESTS SMALL THREAT OF
THUNDERSTORMS OVER THE BLACK HILLS CONVERGENCE ZONE AND ACROSS
NORTHEAST WYOMING WITH DEEP MIXING EARLY THIS EVENING...SO HAVE
ADDED MENTION OF THUNDERSTORMS IN FORECAST. SURFACE LOW DEEPENS
ACROSS EASTERN MONTANA BREEZY/WINDY CONDITIONS EXPECTED ACROSS THE
SOUTH DAKOTA PLAINS. 0-6KM BULK SHEAR SUFFICIENT FOR ROTATING
UPDRAFTS IF THUNDERSTORMS DO DEVELOP. 850MB TEMPERATURES REACH 25-30C
ACROSS NORTHEAST WYOMING/WESTERN SOUTH DAKOTA...WHICH SUPPORTS
HIGHS NEAR 90.
TIGHT PRESSURE GRADIENT OVERNIGHT...WITH BREEZY CONDITIONS ON THE
SOUTH DAKOTA PLAINS. AS A RESULT...HAVE TRENDED LOW TEMPERATURE
FORECAST ABOVE MOS GUIDANCE.
ON THURSDAY...UPPER LOW OVER PACIFIC NORTHWEST LIFTS INTO
CANADA...WITH SURFACE LOW MOVING INTO SOUTHERN
SASKATCHEWAN/MANITOBA. TRAILING COLD FRONT SLIDES INTO THE
WESTERN DAKOTAS/EASTERN WYOMING. SUBTLE DIFFERENCES BETWEEN
NAM/ECMWF/GFS/GEM ON COLD FRONT POSITION THURSDAY
AFTERNOON....RANGING FROM OVER NORTHEAST WYOMING TO EAST OF THE
BLACK HILLS. WELL MIXED BOUNDARY LAYER SUPPORTS HIGHS AROUND 90
AHEAD OF THE FRONT...WITH POST FRONTAL COOLING AND STRATUS
SUPPORTING HIGHS IN THE 70S. MOS GUIDANCE HAS A 15-20F RANGE FOR THURSDAY
HIGHS ACROSS NORTHEAST WYOMING INTO NORTHWEST SOUTH DAKOTA. HAVE TRENDED
TOWARDS A SLOWER PROGRESSION OF COLD FRONT AS UPPER LEVEL JET
REMAINS ACROSS IDAHO/WESTERN MONTANA. SCATTERED THUNDERSTORMS
EXPECTED ALONG AND BEHIND COLD FRONT THURSDAY AFTERNOON/EVENING.
&&
.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 320 AM MDT WED MAY 28 2014
UPPER LEVEL FLOW OVER THE NORTHERN PLAINS REMAINS SOUTHWESTERLY FOR
MUCH OF THE EXTENDED PERIOD AS TROF DIGS ACROSS THE WESTERN CONUS
AND RIDGE HOLDS FAST OVER THE MISSISSIPPI VALLEY. WITH SOUTHWEST
FLOW...THERE WILL BE NEAR DAILY CHANCES FOR SHOWERS AND
THUNDERSTORMS FROM FRIDAY THROUGH THE MIDDLE OF NEXT WEEK. MODEL
CONSENSUS PUTS BEST CHANCES FOR WIDESPREAD PRECIP IN THE FRIDAY TO
SATURDAY NIGHT TIME FRAME...AND AGAIN FROM SUNDAY NIGHT INTO MONDAY.
TEMPERATURES WILL BE NEAR SEASONAL AVERAGES.
&&
.AVIATION...FOR THE 18Z TAFS THROUGH 18Z THURSDAY
ISSUED AT 1120 AM MDT WED MAY 28 2014
VFR CONDITIONS CAN BE EXPECTED THROUGH THURSDAY MORNING. ISOLATED
THUNDERSTORMS WILL BE POSSIBLE FROM NORTHEAST WYOMING INTO FAR
NORTHWEST SD LATE THIS AFTERNOON AND EVENING.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...74
LONG TERM...15
AVIATION...26
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
334 AM MDT WED MAY 28 2014
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 320 AM MDT WED MAY 28 2014
CURRENT SURFACE MAP SHOWS LOW PRESSURE MOVING THROUGH THE GREAT
BASIN WITH DIFFUSE STATIONARY FRONT ACROSS SOUTHERN MONTANA INTO
NORTHERN NORTH DAKOTA. SMALL AREA OF DIMINISHING CONVECTION
LOCATED NEAR THE BLACK HILLS.
FOR TODAY...UPPER TROF MOVES THROUGH THE PACIFIC NORTHWEST...WITH
RIDGE BUILDING ACROSS THE DAKOTAS. LARGE SCALE SUBSIDENCE ACROSS
THE DAKOTAS WITH Q-VECTOR DIVERGENCE. HIGH BOUNDARY LAYER MOISTURE
WILL RESULT IN MLCAPE AROUND 1500J/KG. WITH MLCIN AROUND 100
J/KG AND LACK OF FORCING...WILL MAINTAIN DRY FORECAST THROUGH THE
AFTERNOON. LATEST RUN OF HRRR SUGGESTS SMALL THREAT OF
THUNDERSTORMS OVER THE BLACK HILLS CONVERGENCE ZONE AND ACROSS
NORTHEAST WYOMING WITH DEEP MIXING EARLY THIS EVENING...SO HAVE
ADDED MENTION OF THUNDERSTORMS IN FORECAST. SURFACE LOW DEEPENS
ACROSS EASTERN MONTANA BREEZY/WINDY CONDITIONS EXPECTED ACROSS THE
SOUTH DAKOTA PLAINS. 0-6KM BULK SHEAR SUFFICIENT FOR ROTATING
UPDRAFTS IF THUNDERSTORMS DO DEVELOP. 850MB TEMPERATURES REACH 25-30C
ACROSS NORTHEAST WYOMING/WESTERN SOUTH DAKOTA...WHICH SUPPORTS
HIGHS NEAR 90.
TIGHT PRESSURE GRADIENT OVERNIGHT...WITH BREEZY CONDITIONS ON THE
SOUTH DAKOTA PLAINS. AS A RESULT...HAVE TRENDED LOW TEMPERATURE
FORECAST ABOVE MOS GUIDANCE.
ON THURSDAY...UPPER LOW OVER PACIFIC NORTHWEST LIFTS INTO
CANADA...WITH SURFACE LOW MOVING INTO SOUTHERN
SASKATCHEWAN/MANITOBA. TRAILING COLD FRONT SLIDES INTO THE
WESTERN DAKOTAS/EASTERN WYOMING. SUBTLE DIFFERENCES BETWEEN
NAM/ECMWF/GFS/GEM ON COLD FRONT POSITION THURSDAY
AFTERNOON....RANGING FROM OVER NORTHEAST WYOMING TO EAST OF THE
BLACK HILLS. WELL MIXED BOUNDARY LAYER SUPPORTS HIGHS AROUND 90
AHEAD OF THE FRONT...WITH POST FRONTAL COOLING AND STRATUS
SUPPORTING HIGHS IN THE 70S. MOS GUIDANCE HAS A 15-20F RANGE FOR THURSDAY
HIGHS ACROSS NORTHEAST WYOMING INTO NORTHWEST SOUTH DAKOTA. HAVE TRENDED
TOWARDS A SLOWER PROGRESSION OF COLD FRONT AS UPPER LEVEL JET
REMAINS ACROSS IDAHO/WESTERN MONTANA. SCATTERED THUNDERSTORMS
EXPECTED ALONG AND BEHIND COLD FRONT THURSDAY AFTERNOON/EVENING.
&&
.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 320 AM MDT WED MAY 28 2014
UPPER LEVEL FLOW OVER THE NORTHERN PLAINS REMAINS SOUTHWESTERLY FOR
MUCH OF THE EXTENDED PERIOD AS TROF DIGS ACROSS THE WESTERN CONUS
AND RIDGE HOLDS FAST OVER THE MISSISSIPPI VALLEY. WITH SOUTHWEST
FLOW...THERE WILL BE NEAR DAILY CHANCES FOR SHOWERS AND
THUNDERSTORMS FROM FRIDAY THROUGH THE MIDDLE OF NEXT WEEK. MODEL
CONSENSUS PUTS BEST CHANCES FOR WIDESPREAD PRECIP IN THE FRIDAY TO
SATURDAY NIGHT TIME FRAME...AND AGAIN FROM SUNDAY NIGHT INTO MONDAY.
TEMPERATURES WILL BE NEAR SEASONAL AVERAGES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 320 AM MDT WED MAY 28 2014
MAINLY VFR CONDITIONS CAN BE EXPECTED THROUGH THURSDAY MORNING.
ISOLATED THUNDERSTORMS WILL BE POSSIBLE ACROSS NORTHEAST WYOMING AND
THE BLACK HILLS LATE THIS AFTERNOON AND EVENING.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...74
LONG TERM...15
AVIATION...15
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1156 PM CDT TUE MAY 27 2014
.DISCUSSION...
SEE THE 06Z AVIATION DISCUSSION BELOW.
40
&&
.AVIATION...
HAVE TWEAKED THE TIMING FROM THE 00Z PACKAGE. AT 05Z THE UPPER
LOW WAS LOCATED ALONG THE RED RIVER JUST WEST OF THE ARKLATX. AS
WAS THE CASE AT 00Z...THE RAP13 LOOKED TO BE INITIALIZING BEST.
AN ANALYSIS OF THE 00Z UPPER AIR LEVELS SHOWED THE BEST MOISTURE
FROM METRO HOUSTON TO THE COAST WITH A SPLITTING JET PATTERN
OVERHEAD. AN AREA OF SHOWERS AND THUNDERSTORMS DEVELOPING NEAR
KCLL AND KUTS AT 0530Z SHOULD MOVE EAST OF THESE SITES BY AROUND
07Z. THE RAP ALSO BRINGS THE BEST TIMES FOR THUNDERSTORMS AT
KCXO...KIAH...KHOU...AND KSGR BETWEEN 07Z AND 13Z. KHOU MAY BE ON
THE EDGE...BUT KLBX AND KGLS WILL PROBABLY SEE BEST THUNDERSTORM
CHANCES BETWEEN 09Z AND 17Z.
WITH THE UPPER LOW STILL NEAR THE AREA...FELT THAT CHANCES FOR
SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE MID AFTERNOON
PERIOD.
40
&&
.PREV DISCUSSION... /ISSUED 907 PM CDT TUE MAY 27 2014/
UPDATE...
SEE EVENING UPDATE.
DISCUSSION...
AT 01Z...A WEAK AREA OF LOW PRESSURE WAS LOCATED NEAR DEL RIO WITH
A WEAK TROUGH OF LOW PRESSURE EXTENDING TO THE NORTHEAST ACROSS
CENTRAL TEXAS. NUMEROUS RESIDUAL BOUNDARIES ARE SCATTERED ACROSS
THE EASTERN HALF OF THE STATE. SFC DEW PTS WERE BEGINNING TO MAKE
A SLOW RECOVERY AND WERE NOW APPROACHING 70 DEGREES AGAIN. SHOWERS
CONTINUE TO DEVELOP OVER THE EXTREME NORTHERN PART OF SE TX WHILE
THE SOUTHERN 2/3RDS OF THE CWA IS RAIN FREE. SOME DECENT RAINFALL
TOTALS YET AGAIN TODAY WITH 3-4 INCH TOTALS FROM BURTON TO WALLER
AND 3 TO 6 INCHES FROM CENTRAL TRINITY COUNTY ACROSS NORTHERN POLK
COUNTY. 00Z 850 MB ANALYSIS SHOWS A GOOD SWATH OF 850 MB MSTR
FROM CRP TO LCH. AN 850 MB LOW WAS LOCATED OVER SE OK WITH A WEAK
TROUGH EXTENDING TO THE SW. AT 700 MB...THE DEEPEST MOISTURE WAS
CONFINED TO EXTREME SE TX INTO SW LA AND A 700 MB LOW WAS STACKED
OVER THE 850 MB LOW IN SE OK. THE 500 MB LOW WAS ALSO OVER SE OK
WITH WITH THE DEEPER MOISTURE CONFINED TO SOUTHERN LA. AT 300
MB...WINDS SPLIT OVER EAST TEXAS WITH STRONG DIVERGENCE NOTED OVER
EAST TEXAS AND MOST OF LA.
THUS FAR TONIGHT...THE HRRR AND RAP 13 HAVE INITIALIZED BEST AND
WILL LEAN TOWARD THEIR SOLUTIONS. THE CONVECTION OVER THE FAR
NORTHERN ZONES SHOULD WANE IN THE NEXT HOUR OR SO AND THEN BEGIN
TO REDEVELOP AROUND 08Z AS THE NEXT PIECE OF ENERGY ROTATES AROUND
THE UPPER LOW AND APPROACHES SE TX. THIS AREA OF STORMS WILL
BEGIN TO SLIDE SE AND MERGE WITH STORMS OVER LOUISIANA THAT WILL
LIKELY BE BACKBUILDING ALONG THE TEXAS COAST. BEST RAIN CHANCES
SHOULD BE OVER THE EASTERN HALF AND COASTAL SECTIONS OF SE TX
VERY LATE TONIGHT INTO WEDNESDAY MORNING. WILL RAISE POPS AFTER
06Z FOR THE EXTREME SE. WILL FRESHEN UP THE FFA AND EXTEND THE
WATCH TO NOON WEDNESDAY. NEW ZONES OUT 930 PM. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 68 83 69 85 70 / 60 50 40 50 30
HOUSTON (IAH) 71 84 70 84 70 / 90 90 40 50 30
GALVESTON (GLS) 72 82 73 82 75 / 90 90 40 50 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR THE FOLLOWING
ZONES: AUSTIN...BRAZORIA...BRAZOS...BURLESON...CHAMBERS...
COLORADO...FORT BEND...GALVESTON...GRIMES...HARRIS...
HOUSTON...JACKSON...LIBERTY...MADISON...MATAGORDA...
MONTGOMERY...POLK...SAN JACINTO...TRINITY...WALKER...
WALLER...WASHINGTON...WHARTON.
GM...NONE.
&&
$$
DISCUSSION...43
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1114 PM EDT THU MAY 29 2014
.SYNOPSIS...
BACKDOOR COLD FRONT WILL STALL IN THE CAROLINAS TONIGHT. HIGH
PRESSURE WILL BUILD IN OVER THE EASTERN UNITED STATES BY THE
WEEKEND WITH SLIGHTLY COOLER AND DRIER AIR FOR SATURDAY AND
SUNDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 1115 PM EDT THURSDAY...
LATEST RADAR TRENDS AND NEAR TERM GUIDANCE...SUCH AS HRRR AND
RAP...SHOWING CLEARER SIGNS THAT THERE WILL BE LITTLE IF ANY
ADDITIONAL DEVELOPMENT OF SHOWERS OR STORMS ACROSS THE
AREA...ONCE THE ACTIVITY ACROSS FOOTHILLS AND BLUE RIDGE OF NW NC
TAPERS OFF...WHICH IT IS SLOWLY DOING. STILL ABOUT 500 J/KG SBCAPE
DOWN IN THAT AREA...BUT THINK BY MIDNIGHT TO 1 AM THIS SHOULD BE
FADING QUICKLY. SO HAVE DECIDED TO LOWER POPS CONSIDERABLY
ELSEWHERE TO SLIGHT CHC...WAS HESTITANT TO DROP ALL MENTION...AND
KEEP LIKELY POPS QUICKLY TAPERING TO CHC ACROSS THE FAR SW CORNER
OF THE FCST AREA. NO OTHER CHANGES FOR REST OF OVERNIGHT.
PREV DISCUSSION AS OF 950 PM EDT THURSDAY...
MOST SHOWERS AND STORMS HAVE DIMINISHED SIGNIFICANTLY...WITH THE
EXCEPTION OF THE FOOTHILL OF NW NC NEAR LOCATION OF BACKDOOR COLD
FRONT WHERE SOME WEAK SFC INSTABILITY STILL EXISTS. THESE ARE SLOW
MOVING AND VERY HEAVY RAIN PRODUCERS...BUT THREAT FOR ANY SEVERE
WEATHER IS OVER. THIS FAR SW CORNER OF THE CWA FROM SMYTH COUNTY
TO WILKES AND YADKIN IS ABOUT THE ONLY PLACE WHERE THUNDERSTORMS
ARE LIKELY THE REMAINDER OF THE EVENING...BUT LEFT A SLIGHT CHC
FOR THUNDER ELSEWHERE FOR A COUPLE MORE HOURS. OTHERWISE JUST CHC
SHOWERS AND EVEN REDUCED SOME AREAS TO SLIGHT CHC AFTER MIDNIGHT.
STILL SOME SIGNIFICANT DISCREPANCIES IN HIGH RES SHORT TERM
GUIDANCE REGARDING HOW MUCH SHOWER ACTIVITY MAY LINGER WELL PAST
MIDNIGHT...AND WHILE LEANING TOWARD THOSE SOLUTIONS WITH MOST
LIMITED COVERAGE...LOWER LEVELS STILL VERY STATURATED AND WHILE
UPSLOPE FLOW FROM NORTHEAST IS VERY SHALLOW AND WEAK...COULD BE
SOME AREAS OF DRIZZLE AND FEW MORE SHOWERS THAN SOME OF THESE
MODELS SUGGEST...SO DIDN`T WANT TO DROP PRECIP CHANCES DOWN TO
SLIGHT CHC EVERYWHERE. THIS STILL MAY NEED TO BE ADJUSTED FURTHER
THOUGH. AGAIN...BEST CHANCES FOR ONGOING SHOWER/TSTORM ACTIVITY
WILL BE ACROSS FAR SW PART OF AREA REST OF THE NIGHT.
OTHER MAIN CHANGE WAS TO INTRODUCE PATCHY FOG EARLIER PER SOME
RECENT OBSERVATIONS AND JUST PUT THIS EVERYWHERE SINCE ITS HARD TO
PINPOINT ALL THE LOCATIONS THAT WILL SEE THIS...MOST LIKELY HIGHE
RIDGES AND LOCATIONS THAT HAVE GOTTEN RECENT RAIN. ALSO WIDENED AREAS
OF FOG AFTER MIDNIGHT FOR NOT JUST PIEDMONT BUT ALSO WEST OVER
BLUE RIDGE AND INTO PARTS OF NRV AND ROANOKE VALLEY.
TEMPS WILL NOT DROP ALL THAT QUICKLY THROUGH REST OF
OVERNIGHT...BUT GOING MIN TEMPS STILL LOOK OK...ALTHOUGH DROPPED
BLF AREA A LITTLE BIT MORE SINCE THEY ARE ALREADY CLOSE TO PREV
FCST MIN.
PREV DISCUSSION AS OF 705 PM EDT THURSDAY...
BACKDOOR FRONT APPEARS TO BE MOST OF THE WAY THROUGH FCST AREA
EXCEPT PERHAPS FOR FAR SW VA AND NW NC. TEMPS...AIDED BY SHOWERS
AND THUNDERSTORMS AHVE COOLED INTO THE 60S MOST LOCATIONS...WITH A
FEW 70S NW NC FOOTHILLS. LOWER STRATUS STILL IN PIEDMONT OF VA.
MAIN FCST CHANGES WERE TO ADJUST FOR CURRENT COOLER TEMPS AND
ACCOUNT FOR HIGHER POPS MOVING FARTHER INTO MORE STABLE AIR OF VA
PIEDMONT PER LATEST RADAR...BUT LIMIT THUNDER EAST OF LYH.
STRONGER STORMS IN ALLEGHENY HIGHLANDS EARLIER SHOULD CONTINUE TO
WEAKEN AND BELIEVE THAT MAIN CONCERN FOR REMAINDER OF EVENING IS
LOCALLY HEAVY RAINFALL AND MINOR FLOODING...ESPECIALLY MORE URBAN
AREAS...RATHER THAN MUCH CHANCE FOR ANY WIND DAMAGE OR HAIL.
SBCAPE OF OVER 1000 J/KG CONFINED NOW TO NW NC. STILL...WHERE SOME
INSTABUILITY PERSISTS INTO LATE EVENING...COULD CONTINUE TO SEE
SHOWERS WITH SOME EMBEDDED THUNDER CONTINUE SLOWLY DRIFTING TO THE
SOUTHEAST.
PREV DISCUSSION AS OF 407 PM EDT THURSDAY...
500 MB TROF AMPLIFIES ALONG THE EAST COAST TONIGHT INTO FRIDAY.
SHORTWAVE AND ASSOCIATED JET STREAK DROPS SOUTHEAST FROM THE OHIO
VALLEY INTO NORTH CAROLINA BY MIDNIGHT. HIGH PRESSURE OVER NEW
ENGLAND RIDGING DOWN INTO THE MID ATLANTIC REGION. BACKDOOR COLD
FRONT...HIGHLIGHTED NICELY BY MSAS ANALYSIS OF LIFTED INDEX AND
PRESSURE CHANGES...PUSHING SOUTHWARD INTO THE FORECAST AREA
THIS AFTERNOON.
THE COMBINATION OF LOW LEVEL CONVERGENCE ALONG THE SURFACE FRONT AND
THE LIFT FROM THE PASSING SHORTWAVE WILL RESULT IN SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS THIS AFTERNOON INTO TONIGHT. THE
BEST CHANCE FOR CONVECTION WILL OCCUR ALONG AND SOUTH OF THE
BACKDOOR COLD FRONT WITH BEST DESTABILIZATION. MEANWHILE...AN AREA
OF SHOWERS AND THUNDERSTORMS ACROSS SOUTHERN OHIO AND WEST VIRGINIA
WILL TRAVEL SOUTHEAST INTO OUR REGION TONIGHT. THIS AREA OF
CONVECTION WILL PROBABLY STRATIFY AS IT ENTER THE MOUNTAINS. RICH
BOUNDARY LAYER MOISTURE COMBINED WITH HEALTHLY LOW AND MID-LEVEL
LAPSE RATES AND STRONG INSOLATION SOUTH TO SOUTHWEST OF THE BACKDOOR
COLD FRONT RESULTING IN MODERATE DESTABILIZATION WITH MLCAPE VALUES
AROUND 1000 J/KG THIS AFTERNOON...SUGGESTING THAT A FEW ROBUST
UPDRAFTS MAY BE POSSIBLE. A STRONGER THUNDERSTORM THIS AFTERNOON
INTO TONIGHT COULD CONTAIN GUSTY WINDS...HAIL AND HEAVY DOWNPOURS.
SWODY1 HAD A SEE TEXT FOR STRONGER STORMS ACROSS SOUTHERN NORTH
CAROLINA AND SOUTH CAROLINA. THE MAIN CONCERN IS FOR LOCALLY DMGG
WIND...ALTHOUGH THE RISK SEEMS DIMINISHED...BECAUSE OF LOWER
DCAPE...RELATIVE TO YESTERDAY.
IN THE WAKE OF THE SHORTWAVE AND BEHIND THE COLD FRONT...EXPECT
CLOUDS AND AREAS OF LIGHT RAIN...DRIZZLE AND FOG. THE FRONTAL
BOUNDARY MAY PROVIDE THE FOCUS FOR CONVECTION TO CONTINUE INTO THE
OVERNIGHT. WITH SLOW MOVING THUNDERSTORMS WITH HEAVY RAIN AND
TRAINING OF STORMS...THERE IS THE POTENTIAL FOR FLOODING PROBLEMS
ESPECIALLY ENHANCED BY THE EASTERLY WINDS ALONG THE EASTERN SLOPES
OF THE BLUE RIDGE MOUNTAINS. PLAYED LOW TEMPERATURES CLOSE TO THE
ADJMETBC WITH READINGS FROM THE MID 50S IN THE NORTHWEST MOUNTAINS
TO THE LOWER 60S IN THE PIEDMONT.
THE CLASHING OF AIRMASSES AND SURFACE CONVERGENCE KEEPS SHOWERS AND
THUNDERSTORMS IN THE FORECAST ACROSS SOUTHERN PORTIONS OF FORECAST
AREA MAINLY IN NORTHWEST NORTH CAROLINA AND EXTREME SOUTHWEST
VIRGINIA ON FRIDAY. SWODY2 PLACED GENERAL THUNDER BASICALLY WEST OF
I77. CLOUD COVER WILL HINDER ANY SEVERE THREAT IN SOUTHERN
APPALACHIANS. HIGHS TEMPERATURES FRIDAY WILL BE BELOW
NORMAL...EXCEPT EXTREME SW VA AND SE WEST VA. HIGHS ON FRIDAY WILL
RANGE FROM THE LOWER 70S TO AROUND 80 DEGREES.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 330 PM EDT THURSDAY...
REX BLOCK MID CONUS WILL PREVENT NORMAL WEST TO EAST PROGRESSION OF
WEATHER SYSTEMS THROUGH THE WEEKEND. CUTOFF LOW VCNTY OF THE MID MS
VALLEY IS FORECAST TO GRADUALLY WEAKEN...TAKING SEVERAL DAYS TO
BREAK DOWN BEFORE THE WESTERLIES KICK BACK IN NEXT WEEK. MEANWHILE A
DEEPENING UPPER TROUGH OVER NEW ENGLAND WILL DO MORE TO INFLUENCE
OUR WEATHER BY SUBJECTING THE FORECAST AREA TO A SEVERAL DAY PERIOD
OF EASTERLY FLOW WHICH TYPICALLY MEANS COOLER THAN NORMAL
TEMPERATURES AND POTENTIAL FOR LOW LEVEL CLOUDINESS TO GET STUCK
AGAINST THE BLUE RIDGE. MODEL SOUNDINGS HINT AT JUST THAT...WITH A
SHALLOW LAYER OF LOW LEVEL MOISTURE BANKED UP AGAINST THE EAST SIDE
OF THE BLUE RIDGE FRIDAY NIGHT THROUGH SUNDAY MORNING...IN ADDITION
TO THE POTENTIAL FOR DRIZZLE/FOG VCNTY OF THE BLUE RIDGE. WITH THIS
SORT OF PATTERN WILL FAVOR THE COOLER SIDE OF GUIDANCE...ESP EAST OF
THE APPALACHIAN DIVIDE.
BEGINNING SUNDAY...AND MORE SO FOR MONDAY...THE NEW ENGLAND TROUGH
WILL MOVE WELL OFF SHORE WITH BUILDING HEIGHTS. THIS WILL TURN THE
WIND DIAL MORE TO A SOUTHERLY DIRECTION...AND BEGIN THE WARM UP
PROCESS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 245 PM EDT THURSDAY...
THE UPPER FLOW PATTERN NEXT WEEK FEATURES A PERSISTENT UPPER RIDGE
CENTERED OVER NORTHERN MEXICO...EXTENDING EAST ACROSS THE SOUTHERN
CONUS...INCLUDING THE SOUTHEAST STATES. NORTH OF THIS RIDGE...A
MORE ZONAL TYPE PATTERN WILL EXISTS ACROSS THE CENTRAL AND NORTHERN
CONUS...ALTHOUGH VERY NOISY...WITH EMBEDDED SHORT WAVE ENERGY
RIPPLING EAST WITHIN THE FASTER WESTERLY WINDS ALOFT.
WITH THE EXTENSION OF THE UPPER RIDGE COVERING THE SOUTHEAST STATES
WINDS SURFACE AND ALOFT WILL BE OUT OF THE WEST OR SOUTHWEST. THIS
WILL FAVOR A MORE SUMMER LIKE PATTERN WITH TEMPERATURES CLIMBING
ABOVE NORMAL...MODEL GUIDANCE SUGGESTING READINGS ABOUT 10 DEGREES
ABOVE THE NORM FOR DAYTIME HIGHS AND AT LEAST 5 DEGREES ABOVE THE
NORM FOR OVERNIGHT LOWS.
THE PATTERN ALSO SUGGESTS THE FORECAST AREA WILL BE SUBJECT TO A
DAILY THREAT OF SHOWERS AND THUNDERSTORMS...NOTHING ORGANIZED PER SE
OR LASTING FOR ANY SIGNIFICANT LENGTH OF TIME...BUT MAINLY SCATTERED
IN NATURE. IF THERE IS ANYTHING CLOSE TO BEING ORGANIZED IF WILL
MOST LIKELY COME FROM SOMETHING GENERATED OVER THE OHIO VALLEY
ASSOCIATED WITH ONE OF THE SHORTWAVE DISTURBANCES ALOFT...THIS
ACTIVITY POTENTIALLY MOVING DOWNSTREAM INTO OUR FORECAST AREA IN THE
FORM OF THUNDERSTORM CLUSTERS OR A SQUALL LINE. OUTSIDE OF THIS
UPSTREAM THREAT...LOCAL THUNDERSTORM DEVELOPMENT WILL BE THE TYPICAL
DIURNALLY DRIVEN DEEP CONVECTION...WITH BEST CHANCES IN THE
MOUNTAINS ESPECIALLY ALONG THE BLUE RIDGE WHERE WIND CONVERGENCE
WILL BE THE GREATEST. IF THE WINDS ALOFT BECOME PURE WESTERLY...A
LEE TROUGH WILL FORM OVER THE PIEDMONT WHICH COULD AID IN SCATTERED
LATE AFTERNOON STORM DEVELOPMENT THERE TOO.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
AS OF 755 PM EDT THURSDAY...
COVERAGE OF SHOWERS AND THUNDERSTORMS QUICKLY DIMINISHING ACROSS
THE REGION AND DO NOT EXPECT ANY MORE THUNDER AT ANY TAF SITES
REMAINDER OF THE EVENING. SHOWERS STILL POSSIBLE THROUGH ABOUT
04Z AT LYH AND DAN...AND ONLY THROUGH ABOUT 01 0R 02Z AT BCB AND
ROA. CIGS AT ROA AND LYH ALREADY IFR OR LIFR BEHIND BACK DOOR
FRONT...AND EXPECT CIGS/VSBYS TO DROP TO IFR ALL TAF SITES OVER
THE NEXT FEW HOURS AND BY MIDNIGHT ALL BUT PERHAPS BLF WILL BE
IFR. LIFR IN FOG ALSO LIKELY BEFORE WELL BEFORE DAWN AS
WELL.
WITH NORTH TO NORTHEAST FLOW BEHIND THIS FRONT DURING THE DAY FRIDAY...
EXPECT ONLY A VERY SLOW RETURN TO ABOVE IFR CIGS...LIKELY WELL
INTO THE AFTERNOON AT AIRPORTS EAST OF BLUE RIDGE...AND MANY MAY
REMAIN MVFR. BLF AND LWV MOST LIKELY TO SEE VFR DURING THE DAY.
CANNOT RULE OUT A BRIEF SHOWER IN THE MORNING AT BLF AND
BCB...PERHAPS ALSO DAN...WITH SHORT WAVE SLIDING ACROSS FRONTAL
BOUNDARY...BUT MUCH DRIER AIR FILTERS IN LATER IN THE DAY UNDER
HIGH PRESSURE...WHICH WILL HELP THE EVENTUAL RETURN TO VFR.
INTO FRIDAY NIGHT...SOME IFR CONDITIONS COULD RETURN...FOR BLF
AND LWB MAINLY...LOWER CONFIDENCE AT BCB...WITH SOME LOW LEVEL
MOISTURE TRAPPED BELOW INVERSION. THEN VFR CONDITIONS WILL
PREVAIL FOR THE WEEKEND...EXCEPT FOR BRIEFLY OVERNIGHT IN
MOUNTAIN VALLEYS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/KK
NEAR TERM...KK/SK
SHORT TERM...PM
LONG TERM...PM
AVIATION...AMS/KK/SK
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
[top]
Area Forecast Discussion
National Weather Service Spokane WA
451 PM PDT THU MAY 29 2014
.SYNOPSIS...
Showers and isolated thunderstorms will be confined mainly to the
northern mountains this evening as a low pressure system pulls
away from the region. Much warmer weather develops Friday and
continues into the weekend. Many areas will be in the upper 70s
to lower 80s Friday through Wednesday. Most areas will be dry
through the middle of next week...shower or thunderstorm
development is possible in the mountains each afternoon and
evening.
&&
.DISCUSSION...
Tonight: Although temperatures are warming aloft with the upper
level low pressure system well off to the northeast now, we are
still holding onto to some weak surface based instability across
the Northeast Mtns. A weak impulse moving through the northwest
flow out of BC is triggering a batch of showers near Republic. The
HRRR model takes these showers and slides them southeast with time
this evening. This will impact the communities of Colville,
Metaline Falls and eventually into Sandpoint and Bonners Ferry if
they continue to hold together that long. These showers seem to
be producing fairly weak updrafts due to only a marginally
unstable atmosphere, so not convinced we will see any lightning
from these showers through the rest of the afternoon into the
evening; however, guidance off of the HRRR and SPC SREF page
indicates a slight chance that we could still see a thunderstorm
develop up till about 8:00 PM this evening or so. Showers will
quickly dissipate over the evening as we lose our daytime heating.
Skies will clear out overnight with dew points sitting in the low
to mid 30s. Winds will also be light and strong radiational
cooling is anticipated to take place overnight. Expect lows
tonight to drop into the low to mid 30s across the northern
valleys and colder pockets may drop down to freezing; this will
include locations such as Republic, Springdale and Republic. With
the idea that showers will continue into the evening across the
northern mountains, I added patchy fog to the forecast for late
tonight into early Friday morning.
Friday: We will see a significant rise to temperatures tomorrow of
around 8-10 degrees compared to this afternoon. This will begin a
warming trend into the weekend. Another upper level disturbance,
currently located in northwestern BC, will begin to drop down into
the northern WA Cascades by the afternoon. This will result in
some developing showers north of the Canadian border in BC and
along the Cascade Mtns. These showers may also produce a few
thunderstorms; all other areas will likely remain dry. /SVH
Fri Nt through Sunday: The entire weekend will be dominated by a
slow-moving upper trough...first moving into Ern Wa and N Id Fri
Nt, then not exiting into Wrn Montana until late Sunday. This low
will weaken slowly in general, and is not showing the magnitude
of stretching/strong weakening as model guidance hinted at
yesterday. The good new, at least confidence- wise, is that there
is much more agreement between guidance versus the previous runs.
Even so, there will still be a number of embedded vort maxes
within this upper low, each having the potential to enhance
localized regions of heavier convective pcpn. But given the lack
of notable instability, it`s likely that the pcpn will be dominated
by diurnal processes...ie, the vast majority of the pcpn will be
confined to the afternoon/early evening and driven mostly by
insolation (peak heating) over the elevated heat and moisture
sources of the mountain zones. We`ll be watching closely how these
embedded vort maxes evolve according to the models, then try to
fine tune the fcst to locate the best potential for showers and
thunderstorms. bz
Sunday evening through Thursday...Longwave trof continues to
influence the majority of this time interval. The synoptic
features nested in this longwave trof include a parts of a
shortwave trof and embedded low along with minor disturbances
rotating around its periphery lifting out slowly and clumsily
Sunday evening into Monday evening. This may result in relatively
low pops depicting the low potential for showers and
thunderstorms. Tuesday morning into Tuesday afternoon there is
another hint at a shortwave trof dropping down in a northwest to
southeast trajectory that may be more of a breezy wind and wind
gust maker in addition to having some potential for light
precipitationso more wording for showers and thunderstorms
remain in various shape or form over North Idaho and over and near
the mountainous terrain of Northeast Washington. Wednesday and
Thursday the flow over Eastern Washington and North Idaho still
remains somewhat trof like in appearance but the ECMWF and GFS
differ in timing and passage of northwest to southeast traversing
synoptic/mesoscale features through the trof. So all in all there
really isn`t a period void of pops or a mention of convection in
some shape or form in the forecast area. Since the trof isn`t
substantially deep daytime heating and not too much cloud cover to
inhibit it should result in forecast temperatures on slightly on
the warm side of what would be considered normal for this time of
year. /Pelatti
&&
.AVIATION...
00Z TAFS: The region is under the influence of an upper-level
trough and drier air has infiltrated behind yesterday`s
disturbance. Surface based convection and a few light showers
across the northern mountains will wane by 04z and all terminals
can anticipate mostly clear skies. A second disturbance dropping
into the mean trough will bring a threat for isolated showers and
thunderstorms over the Cascades Friday afternoon will a small
risk that this activity drifts in the vcnty of KEAT...otherwise,
just some passing mid and high level clouds are expected at all
terminals through 00z. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 45 74 50 78 51 78 / 10 0 10 10 20 10
Coeur d`Alene 39 75 46 78 51 78 / 10 0 10 20 20 20
Pullman 36 74 45 75 49 76 / 0 0 20 20 20 20
Lewiston 45 81 52 80 54 82 / 0 0 10 20 20 20
Colville 41 75 44 79 49 80 / 20 10 10 10 10 10
Sandpoint 37 74 44 76 46 72 / 10 0 0 10 10 20
Kellogg 41 74 45 76 48 74 / 0 0 10 20 20 30
Moses Lake 44 80 50 83 51 84 / 0 0 0 0 0 0
Wenatchee 50 80 56 82 56 84 / 0 0 0 0 0 0
Omak 41 78 48 81 49 83 / 10 10 10 0 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
236 PM CDT WED MAY 28 2014
.SHORT TERM...TONIGHT AND THURSDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SEVERAL
SHORTWAVE TROUGHS MOVING SLOWLY SOUTHEAST OVER THE SOUTHERN
WISCONSIN...NORTHERN ILLINOIS...AND EASTERN IOWA REGION. A SURFACE
COLD FRONT LIES FROM SOUTHERN IOWA TO NORTHERN INDIANA AND MARKS
THE TRANSITION FROM A HUMID SUMMER AIRMASS AND A MUCH COOLER/DRIER
CANADIAN AIRMASS. A FEW LIGHT SHOWERS AND SPRINKLE CONTINUE TO
SHOW UP ON AREA RADARS EARLY THIS AFTERNOON OVER SOUTH-CENTRAL AND
SOUTHEAST WISCONSIN WHERE MID-LEVEL MOISTURE HAS YET TO DEPART...BUT
THE DEEPER CONVECTION RESIDES CLOSER TO THE FRONT JUST SOUTH OF
THE INTERSTATE 80 CORRIDOR. THE BACK EDGE OF THE MID-LEVEL CLOUD
DECK CONTINUES TO GRADUALLY DROP SOUTHWARD OVER CENTRAL AND
NORTHERN WISCONSIN. FORECAST CONCERNS INCLUDE LIGHT SHOWER AND
CLOUD TRENDS FOLLOWED BY TEMPS.
TONIGHT...SHORTWAVE TROUGHING OVER THE WESTERN GREAT LAKES WILL
SLIDE GRADUALLY SOUTHWARD AND WEAKEN AT THE SAME TIME. SCATTERED
TO BROKEN MID-LEVEL CLOUDS WILL BE LINGERING AT LEAST ALONG AND
SOUTH OF INTERSTATE 94 AT THE START OF THE EVENING IF NOT A LITTLE
FARTHER NORTH...BUT WILL END THE LIGHT SHOWER OR SPRINKLE CHANCE
AT THE START OF THE PERIOD. THEN WILL SEE A SLOW DECREASING CLOUD
TREND FROM NORTH TO SOUTH OVER THE COURSE OF THE NIGHT. IT WILL BE
A COOLER AND LESS HUMID NIGHT WITH TEMPS RANGING FROM THE MID 40S
TO MID 50S.
THURSDAY...HUDSON BAY HIGH PRESSURE WILL BUILD SOUTHWARD OVER THE
CENTRAL GREAT LAKES. NORTHEAST WINDS ORIGINATING OUT OF THIS HIGH
WILL ADVECT A DRY AIRMASS INTO THE REGION. SHOULD SEE PLENTY OF
SUNSHINE WITH HIGHS RANGING THROUGH THE 70S EXCEPT NEAR LAKE
MICHIGAN.
.LONG TERM...THURSDAY NIGHT THROUGH NEXT WEDNESDAY.
THURSDAY NIGHT THROUGH SATURDAY...THE HIGH PRESSURE SYSTEM WILL BE
HANGING AROUND THE REGION THROUGH FRIDAY NIGHT...THEN BEGIN TO
DEPART TO THE EAST ON SATURDAY. AS A RESULT...SHOULD SEE MOSTLY CLEAR AND
PLEASANT CONDITIONS OVER THE PERIOD. TEMPERATURES WILL WARM A
DEGREE OR TWO ON BOTH FRIDAY AND SATURDAY. LOWS MAINLY IN THE
50S.
REST OF THE FORECAST...A CHANGE OF AIRMASS WILL OCCUR SATURDAY
NIGHT INTO SUNDAY WHEN A WARM FRONT MOVES EAST ACROSS THE REGION.
PWATS WILL INCREASE UPWARDS OF 1.50 TO 1.75 INCHES AND WILL HAVE
WEAK SHORTWAVE ENERGY TRAVERSING THE NORTHERN MISSISSIPPI VALLEY.
SHOWER AND THUNDERSTORM CHANCES WILL IMPROVE SATURDAY NIGHT OVER
THE WESTERN FORECAST AREA AND ON SUNDAY ACROSS EAST. WILL LIKELY
SEE A LARGE DIURNAL COMPONENT TO THE CONVECTION SINCE FORCING
ALOFT IS RELATIVELY WEAK. THE THREAT OF STORMS WILL CONTINUE
THROUGH TUESDAY WHEN A COLD FRONT MOVES ACROSS THE REGION. LIKE
THE PREVIOUS FORECASTER MENTIONED...THE THREAT OF SEVERE STORMS IS
ON THE LOW SIDE DUE TO WEAK WIND FIELDS ALOFT ON SUNDAY AND
MONDAY...BUT COULD IMPROVE AHEAD OF THE COLD FRONT HEADING INTO
TUESDAY.
&&
.MARINE...NORTHEAST WINDS WILL DIMINISH LATE TONIGHT AND LEAD TO
SUBSIDING WAVES. LIGHT NORTHEAST FLOW WILL THEN CONTINUE INTO
FRIDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/THURSDAY AND AVIATION/MARINE...MPC
THURSDAY NIGHT THROUGH WEDNESDAY...MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1235 PM CDT WED MAY 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CDT WED MAY 28 2014
LATEST WATER VAPOR AND 500 MB RAP ANALYSIS SHOWED AN UPPER LEVEL
TROUGH OVER THE FORECAST AREA WHICH WAS RESPONSIBLE FOR TRIGGERING
THE SHOWERS AND THUNDERSTORMS ON TUESDAY. SURFACE HIGH PRESSURE
WAS CENTERED NEAR HUDSON BAY AND WAS STARTING TO BUILD SOUTHWEST.
THE TROUGH/SURFACE LOW WILL SLIDE SOUTHEAST TODAY WITH THE HIGH
BUILDING INTO THE FORECAST AREA FROM NORTHEAST TO SOUTHWEST.
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN THIS MORNING INTO
EARLY THIS AFTERNOON MAINLY OVER FAR SOUTHWEST WISCONSIN AND
NORTHEAST IOWA AND POSSIBLY SOUTHEAST MINNESOTA. THE HIGH THEN
QUICKLY BUILDS IN THIS AFTERNOON WITH SHOWER AND THUNDERSTORMS
BEING PUSHED TO THE SOUTH. THE RAP TAKES THE SHOWERS AND
THUNDERSTORMS OUT OF THE FORECAST AREA BY 19Z WHILE THE NAM HOLDS
ONTO THE ACTIVITY OVER NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN
THROUGH LATE AFTERNOON. HIRES NMM AND ARW ARE IN LINE WITH THE RAP
PUSHING THIS ACTIVITY SOUTH OF THE FORECAST AREA THIS AFTERNOON
SO WILL LEAN TOWARD THESE FORECAST MODELS FOR PRECIPITATION
CHANCES THIS AFTERNOON. CLOUDS LOOK TO LINGER OVER MUCH OF THE
FORECAST AREA THROUGH LATE AFTERNOON THEN ARE EXPECTED TO CLEAR AS
DRIER AIR PUSHES IN FROM THE NORTHEAST. NORTH CENTRAL WISCONSIN
SHOULD CLEAR OUT EARLIER THIS AFTERNOON THEN THIS CLEARING WILL
WORK SOUTHWEST THROUGH THE LATE AFTERNOON HOURS. WITH THE CLEARING
OCCURRING LATE IN THE AFTERNOON AND WITH THE RECENT RAINFALL OVER
THE FORECAST AREA...AREAS OF FOG WILL BE A CONCERN TONIGHT. THERE
IS SOME UNCERTAINTY REGARDING THE EXTENT OF THE FOG WITH THE DRIER
EAST/NORTHEAST FLOW SETTING UP SO WILL HOLD THE FOG COVERAGE AT
PATCHY. THE DRIER AIR AND EARLIER CLEARING OVER NORTH CENTRAL
WISCONSIN SHOULD LIMIT ANY FOG FORMATION OVER THESE AREAS. LOW
TEMPERATURES TONIGHT WILL RANGE FROM THE UPPER 40S OVER NORTH
CENTRAL WISCONSIN TO THE MID 50S ACROSS NORTHEAST IOWA.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 334 AM CDT WED MAY 28 2014
HIGH PRESSURE BUILDS INTO THE REGION ON THURSDAY AND WILL REMAIN IN
CONTROL THROUGH SATURDAY MORNING WITH DRY AND QUIET WEATHER
EXPECTED. HIGH TEMPERATURES WILL RANGE FROM THE UPPER 70S TO
THE LOWER 80S. THE HIGH IS EXPECTED TO SLIDE EAST OF THE REGION
SATURDAY AFTERNOON INTO SATURDAY NIGHT AS SOUTHWEST FLOW ALOFT
SETS UP OVER THE UPPER MISSISSIPPI RIVER VALLEY. AN ACTIVE WEATHER
PATTERN IS IN STORE FOR THE FORECAST AREA STARTING SATURDAY NIGHT
AND PERSISTING THROUGH TUESDAY NIGHT. A FRONTAL BOUNDARY LOOKS TO
SET UP ALONG OR JUST NORTH OF THE INTERSTATE 90 CORRIDOR. THIS
BOUNDARY WILL ACT AS A WARM FRONT FROM LATE THIS WEEKEND INTO
EARLY NEXT WEEK AND IS EXPECTED TO INTERACT WITH A SERIES OF
SHORTWAVES TO GENERATE SHOWERS AND THUNDERSTORMS. WILL HAVE TO
KEEP A VERY CLOSE EYE ON THIS PERIOD WITH THE POTENTIAL TO SEE
SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS. HEAVY RAIN COULD
BECOME A CONCERN IF THIS PATTERN MATERIALIZES. OUTSIDE OF THE
HEAVY RAIN POTENTIAL IT/S DIFFICULT TO NAIL DOWN ANY SPECIFICS ON
OTHER SEVERE WEATHER AT THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1235 PM CDT WED MAY 28 2014
HIGH PRESSURE WILL CONTINUE BUILDING INTO THE AREA TONIGHT INTO
THURSDAY FOR CLEARING SKIES. LIGHT WINDS/MOISTURE FROM RECENT
RAINFALL/CLEAR SKIES MAY LEAD TO SOME PATCHY FOG IN LOWER
LYING AND RIVER VALLEY AREAS. THINKING THERE WILL BE PATCHES OF
FOG AROUND KLSE BUT NOT WIDESPREAD DUE TO 4-6 DEGREE T/TD SPREAD.
IN ADDITION...MODELS SHOW AROUND 10KT OF WIND OUT OF THE EAST AT
BLUFFTOP LEVEL FOR KEEPING THINGS STIRRED. GIVEN THE UNCERTAINTY
AT THIS POINT...WILL GO WITH A P6SM BCFG AT KLSE FROM 08-12Z TIME
FRAME AND HAVE THE EVENING SHIFT CONTINUE MONITORING. KRST LOOKS TO
REMAIN VFR THROUGH THE PERIOD WITH EAST WINDS OF 11-16KT THIS
AFTERNOON DECOUPLING AND REMAINING BELOW 10 KT THROUGH TONIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
651 AM CDT WED MAY 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CDT WED MAY 28 2014
LATEST WATER VAPOR AND 500 MB RAP ANALYSIS SHOWED AN UPPER LEVEL
TROUGH OVER THE FORECAST AREA WHICH WAS RESPONSIBLE FOR TRIGGERING
THE SHOWERS AND THUNDERSTORMS ON TUESDAY. SURFACE HIGH PRESSURE
WAS CENTERED NEAR HUDSON BAY AND WAS STARTING TO BUILD SOUTHWEST.
THE TROUGH/SURFACE LOW WILL SLIDE SOUTHEAST TODAY WITH THE HIGH
BUILDING INTO THE FORECAST AREA FROM NORTHEAST TO SOUTHWEST.
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN THIS MORNING INTO
EARLY THIS AFTERNOON MAINLY OVER FAR SOUTHWEST WISCONSIN AND
NORTHEAST IOWA AND POSSIBLY SOUTHEAST MINNESOTA. THE HIGH THEN
QUICKLY BUILDS IN THIS AFTERNOON WITH SHOWER AND THUNDERSTORMS
BEING PUSHED TO THE SOUTH. THE RAP TAKES THE SHOWERS AND
THUNDERSTORMS OUT OF THE FORECAST AREA BY 19Z WHILE THE NAM HOLDS
ONTO THE ACTIVITY OVER NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN
THROUGH LATE AFTERNOON. HIRES NMM AND ARW ARE IN LINE WITH THE RAP
PUSHING THIS ACTIVITY SOUTH OF THE FORECAST AREA THIS AFTERNOON
SO WILL LEAN TOWARD THESE FORECAST MODELS FOR PRECIPITATION
CHANCES THIS AFTERNOON. CLOUDS LOOK TO LINGER OVER MUCH OF THE
FORECAST AREA THROUGH LATE AFTERNOON THEN ARE EXPECTED TO CLEAR AS
DRIER AIR PUSHES IN FROM THE NORTHEAST. NORTH CENTRAL WISCONSIN
SHOULD CLEAR OUT EARLIER THIS AFTERNOON THEN THIS CLEARING WILL
WORK SOUTHWEST THROUGH THE LATE AFTERNOON HOURS. WITH THE CLEARING
OCCURRING LATE IN THE AFTERNOON AND WITH THE RECENT RAINFALL OVER
THE FORECAST AREA...AREAS OF FOG WILL BE A CONCERN TONIGHT. THERE
IS SOME UNCERTAINTY REGARDING THE EXTENT OF THE FOG WITH THE DRIER
EAST/NORTHEAST FLOW SETTING UP SO WILL HOLD THE FOG COVERAGE AT
PATCHY. THE DRIER AIR AND EARLIER CLEARING OVER NORTH CENTRAL
WISCONSIN SHOULD LIMIT ANY FOG FORMATION OVER THESE AREAS. LOW
TEMPERATURES TONIGHT WILL RANGE FROM THE UPPER 40S OVER NORTH
CENTRAL WISCONSIN TO THE MID 50S ACROSS NORTHEAST IOWA.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 334 AM CDT WED MAY 28 2014
HIGH PRESSURE BUILDS INTO THE REGION ON THURSDAY AND WILL REMAIN IN
CONTROL THROUGH SATURDAY MORNING WITH DRY AND QUIET WEATHER
EXPECTED. HIGH TEMPERATURES WILL RANGE FROM THE UPPER 70S TO
THE LOWER 80S. THE HIGH IS EXPECTED TO SLIDE EAST OF THE REGION
SATURDAY AFTERNOON INTO SATURDAY NIGHT AS SOUTHWEST FLOW ALOFT
SETS UP OVER THE UPPER MISSISSIPPI RIVER VALLEY. AN ACTIVE WEATHER
PATTERN IS IN STORE FOR THE FORECAST AREA STARTING SATURDAY NIGHT
AND PERSISTING THROUGH TUESDAY NIGHT. A FRONTAL BOUNDARY LOOKS TO
SET UP ALONG OR JUST NORTH OF THE INTERSTATE 90 CORRIDOR. THIS
BOUNDARY WILL ACT AS A WARM FRONT FROM LATE THIS WEEKEND INTO
EARLY NEXT WEEK AND IS EXPECTED TO INTERACT WITH A SERIES OF
SHORTWAVES TO GENERATE SHOWERS AND THUNDERSTORMS. WILL HAVE TO
KEEP A VERY CLOSE EYE ON THIS PERIOD WITH THE POTENTIAL TO SEE
SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS. HEAVY RAIN COULD
BECOME A CONCERN IF THIS PATTERN MATERIALIZES. OUTSIDE OF THE
HEAVY RAIN POTENTIAL IT/S DIFFICULT TO NAIL DOWN ANY SPECIFICS ON
OTHER SEVERE WEATHER AT THIS TIME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 651 AM CDT WED MAY 28 2014
THE MAIN FOCUS IS ON THIS MORNING AND WHEN CONDITIONS MAY IMPROVE
AS DRIER AIR MOVES IN FROM THE EAST. MVFR TO LIFR CEILINGS ARE IN
PLACE FROM LSE WEST TO RST AND GUIDANCE IS SAYING THAT CONDITIONS
WILL IMPROVE THROUGH THE MORNING AS THIS COOLER AND DRIER AIR MASS
MOVES IN FROM THE NORTHEAST. SOME SCATTERED SHOWERS ARE EXPECTED
AS WELL...BUT SHOULD STAY LIGHT ENOUGH SO THAT VISIBILITY DOES NOT
DROP. CONDITIONS WILL CONTINUE TO IMPROVE THROUGH THE DAY TO THE
POINT THAT SKIES ARE EXPECTED TO CLEAR OUT BY THIS EVENING. SHOULD
THIS OCCUR...SOME FOG WILL BE POSSIBLE OVERNIGHT. CONFIDENCE WAS
NOT HIGH ENOUGH AT THIS POINT TO PUT IT INTO THE TAF...SO WILL
HAVE TO WATCH TRENDS GOING INTO TONIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
334 AM CDT WED MAY 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CDT WED MAY 28 2014
LATEST WATER VAPOR AND 500 MB RAP ANALYSIS SHOWED AN UPPER LEVEL
TROUGH OVER THE FORECAST AREA WHICH WAS RESPONSIBLE FOR TRIGGERING
THE SHOWERS AND THUNDERSTORMS ON TUESDAY. SURFACE HIGH PRESSURE
WAS CENTERED NEAR HUDSON BAY AND WAS STARTING TO BUILD SOUTHWEST.
THE TROUGH/SURFACE LOW WILL SLIDE SOUTHEAST TODAY WITH THE HIGH
BUILDING INTO THE FORECAST AREA FROM NORTHEAST TO SOUTHWEST.
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN THIS MORNING INTO
EARLY THIS AFTERNOON MAINLY OVER FAR SOUTHWEST WISCONSIN AND
NORTHEAST IOWA AND POSSIBLY SOUTHEAST MINNESOTA. THE HIGH THEN
QUICKLY BUILDS IN THIS AFTERNOON WITH SHOWER AND THUNDERSTORMS
BEING PUSHED TO THE SOUTH. THE RAP TAKES THE SHOWERS AND
THUNDERSTORMS OUT OF THE FORECAST AREA BY 19Z WHILE THE NAM HOLDS
ONTO THE ACTIVITY OVER NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN
THROUGH LATE AFTERNOON. HIRES NMM AND ARW ARE IN LINE WITH THE RAP
PUSHING THIS ACTIVITY SOUTH OF THE FORECAST AREA THIS AFTERNOON
SO WILL LEAN TOWARD THESE FORECAST MODELS FOR PRECIPITATION
CHANCES THIS AFTERNOON. CLOUDS LOOK TO LINGER OVER MUCH OF THE
FORECAST AREA THROUGH LATE AFTERNOON THEN ARE EXPECTED TO CLEAR AS
DRIER AIR PUSHES IN FROM THE NORTHEAST. NORTH CENTRAL WISCONSIN
SHOULD CLEAR OUT EARLIER THIS AFTERNOON THEN THIS CLEARING WILL
WORK SOUTHWEST THROUGH THE LATE AFTERNOON HOURS. WITH THE CLEARING
OCCURRING LATE IN THE AFTERNOON AND WITH THE RECENT RAINFALL OVER
THE FORECAST AREA...AREAS OF FOG WILL BE A CONCERN TONIGHT. THERE
IS SOME UNCERTAINTY REGARDING THE EXTENT OF THE FOG WITH THE DRIER
EAST/NORTHEAST FLOW SETTING UP SO WILL HOLD THE FOG COVERAGE AT
PATCHY. THE DRIER AIR AND EARLIER CLEARING OVER NORTH CENTRAL
WISCONSIN SHOULD LIMIT ANY FOG FORMATION OVER THESE AREAS. LOW
TEMPERATURES TONIGHT WILL RANGE FROM THE UPPER 40S OVER NORTH
CENTRAL WISCONSIN TO THE MID 50S ACROSS NORTHEAST IOWA.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 334 AM CDT WED MAY 28 2014
HIGH PRESSURE BUILDS INTO THE REGION ON THURSDAY AND WILL REMAIN IN
CONTROL THROUGH SATURDAY MORNING WITH DRY AND QUIET WEATHER
EXPECTED. HIGH TEMPERATURES WILL RANGE FROM THE UPPER 70S TO
THE LOWER 80S. THE HIGH IS EXPECTED TO SLIDE EAST OF THE REGION
SATURDAY AFTERNOON INTO SATURDAY NIGHT AS SOUTHWEST FLOW ALOFT
SETS UP OVER THE UPPER MISSISSIPPI RIVER VALLEY. AN ACTIVE WEATHER
PATTERN IS IN STORE FOR THE FORECAST AREA STARTING SATURDAY NIGHT
AND PERSISTING THROUGH TUESDAY NIGHT. A FRONTAL BOUNDARY LOOKS TO
SET UP ALONG OR JUST NORTH OF THE INTERSTATE 90 CORRIDOR. THIS
BOUNDARY WILL ACT AS A WARM FRONT FROM LATE THIS WEEKEND INTO
EARLY NEXT WEEK AND IS EXPECTED TO INTERACT WITH A SERIES OF
SHORTWAVES TO GENERATE SHOWERS AND THUNDERSTORMS. WILL HAVE TO
KEEP A VERY CLOSE EYE ON THIS PERIOD WITH THE POTENTIAL TO SEE
SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS. HEAVY RAIN COULD
BECOME A CONCERN IF THIS PATTERN MATERIALIZES. OUTSIDE OF THE
HEAVY RAIN POTENTIAL IT/S DIFFICULT TO NAIL DOWN ANY SPECIFICS ON
OTHER SEVERE WEATHER AT THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1125 PM CDT TUE MAY 27 2014
MID LEVEL SHORT WAVE THAT BROUGHT CONVECTION EARLIER IS WEAKENING AS
IT SLIDES THROUGH SO INTENSITY OF SHOWERS CONTINUES TO WANE...BUT
PLENTY OF LOW LEVEL MOISTURE REMAINS WRAPPED AROUND POORLY DEFINED
SYSTEM. BULK OF SHOWER ACTIVITY IS NOW ALONG AND NORTH OF INTERSTATE
90 BUT RELATIVELY SMALL AREA OF IFR CEILINGS REMAINS OVER SOUTHEAST
MINNESOTA. GIVEN SLOW MOVEMENT OF THIS FEATURE...HAVE REVERSED
EARLIER THINKING AND ALONG WITH LATEST SREF TRENDS IN KEEPING THESE
CEILINGS AROUND MOST OF NIGHT...HAVE LOWERED FORECAST AT TAF SITES
DELAYING IMPROVING CONDITIONS UNTIL LATER WEDNESDAY MORNING.
STILL A BIT UNCLEAR ON HOW CLOUDS WILL TREND AFTER DAYBREAK BUT
EXPECT SLOW IMPROVEMENT UNTIL LOW LEVEL MOISTURE GETS MORE SHUNTED
SOUTH AS SURFACE HIGH STARTS TO BUILD IN FROM THE NORTH. WOULD
EXPECT AT LEAST A PERIOD OF VFR CONDITIONS. CLEARING SKIES LATE IN
FORECAST COULD LEAD TO FOG POSSIBILITIES HEADING INTO THURSDAY
MORNING AS WELL.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...SHEA
AREA FORECAST DISCUSSION
NWS PUEBLO CO
340 AM MDT FRI MAY 30 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM MDT FRI MAY 30 2014
CURRENTLY...CONVECTION OVER THE FAR EASTERN PLAINS GRADUALLY
FADING AWAY AS OF 09Z...AND WITH LATEST HRRR SUGGESTING LITTLE
PRECIP EAST OF I-25 THROUGH MID MORNING...WILL GO WITH A DRY
FORECAST WITH THE NEW SET OF GRIDS. STILL SOME ISOLATED -SHRA OVER
THE MOUNTAINS AND HIGH VALLEYS...AND WITH PRECIP MOVING TOWARD THE
AREA FROM NRN NM/WRN CO...WILL INCLUDE SOME LOW POPS FOR SHOWERS
OVER MUCH OF THE HIGHER TERRAIN THIS MORNING.
TODAY...MID LEVEL MOISTURE PLUME FIRMLY IN PLACE OVER COLORADO
TODAY...WITH INCREASING LOW LEVEL MOISTURE OVER THE EASTERN
MOUNTAINS AND PLAINS AS WELL. WELL DEFINED SHORT WAVE TROUGH JUST
SOUTH OF THE FOUR CORNERS EARLY THIS MORNING WILL LIFT NORTHEAST
ACROSS THE STATE THROUGH THE DAY...PROVIDING FAIRLY STRONG UPWARD
MOTION. OVERALL...FACTORS LOOK FAIRLY GOOD FOR CONVECTION MOST
AREAS...AND EXPECT STORMS TO FIRE FAIRLY QUICKLY BY LATE MORNING AS
PEAK LIFT FROM THE UPPER WAVE OCCURS FROM MID-MORNING THROUGH MID-
AFTERNOON. NOT MUCH IN THE WAY OF SHEAR FOR SEVERE STORMS
TODAY...THOUGH A COUPLE LOW END PULSE SEVERE HAILERS WILL BE
POSSIBLE. MAIN THREAT WILL BE HEAVY RAIN OVER THE BURN
SCARS...ESPECIALLY BLACK FOREST/WALDO CANYON SCARS WHERE MOISTURE IS
SLIGHTLY DEEPER. CLOUDS AND PRECIP WILL HOLD TEMPS BACK TODAY...WITH
READINGS SEVERAL DEGF COOLER THAN YESTERDAY.
TONIGHT...WITH UPPER WAVE LIFTING NORTHEAST FAIRLY QUICKLY...SUSPECT
MAIN BODY OF CONVECTION WILL BE OVER THE EASTERN PLAINS IN THE LATE
EVENING...THEN MOVE INTO KS OVERNIGHT. STILL ENOUGH MOISTURE FOR A
FEW -SHRA TO LINGER OVER MAINLY THE HIGHER TERRAIN PAST
MIDNIGHT...THOUGH INTENSITY SHOULD BE FAIRLY LIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 316 AM MDT FRI MAY 30 2014
...SEVERE STORMS POSSIBLE SATURDAY...
FAIRLY ACTIVE LATE SPRING PATTERN EXPECTED THIS WEEKEND AND THROUGH
THE EXTENDED...AS A COUPLE SHORT WAVE TROUGHS MOVE THROUGH THE
CENTRAL ROCKIES.
SATURDAY...LOOKS LIKE THE BEST BET IN THE SHORT-MEDIUM RANGE FOR SVR
WX. DEEP SHEAR INCREASES AS THE FIRST SHORT WAVE MOVES FROM THE
INTER-MTN REGION INTO THE ROCKIES. SRLY SURFACE WINDS WILL MAINTAIN
DECENT MOISTURE OVER THE PLAINS THROUGH THE DAY...ALTHOUGH SOME
DRYING MAY OCCUR BY AFTERNOON OVER WRN PORTIONS OF THE CWA. BEST BET
FOR SVR WILL BE E OF A LINE FROM KLHX TO KIM IN THE LATE AFTERNOON
AND EARLY EVE. BULK SHEAR OF 40+ KTS...AND CAPE OF AROUND 1500 J/KG
WILL BE CONDUCIVE TO SUPERCELLS WITH THE POTENTIAL FOR LARGE HAIL
AND DAMAGING WINDS. GENERALLY HIGH LCLS WILL MINIMIZE THE TORNADO
THREAT. STORMS WILL INITIATE OVER THE HYR TRRN...THEN MOVE ONTO THE
PLAINS BY LATE AFTERNOON...EXITING INTO KS BY LATE EVE.
SUNDAY...LESS CERTAINTY ON THE SVR THREAT. DRY W-SW FLOW WILL BE
INCREASING AS THE TROUGH MOVES THROUGH THE NRN ROCKIES...AND A DRY
LINE WILL MIX EWD IN THE AFTERNOON. LOOKS LIKE THE GREATEST THREAT
FOR STRONG STORMS WILL REMAIN E OF THE CWA...BUT THE KS BORDER
COUNTIES COULD POTENTIALLY SEE AN EARLY STORM. SUN SHOULD BE THE
WARMEST DAY OF THE PERIOD...WITH TEMPS TOPPING OUT AS HIGH AS THE
MID 90S OVER THE I-25 CORRIDOR.
MON-WED...LOOKS RELATIVELY DRY AS UPPER FLOW CONTINUES FROM THE W-
SW. IT WILL BE PRETTY WARM OVER THE PLAINS...WITH MAX TEMPS IN THE
UPPER 80S TO NR 90 EACH DAY. COULD SEE SOME MARGINAL FIRE WX THREAT
DEVELOP...ESPECIALLY TUESDAY...AS MID LEVEL FLOW INCREASES TO 40-50
KTS. RED FLAG CONDITIONS WILL LIKELY BE DEPENDENT ON LOCAL FUEL
STATUS DURING THIS PERIOD.
BY THU-FRI...SHOULD SEE TEMPS MODERATE AS THE SECOND SHORT WAVE
TROUGH MOVES THROUGH CO. THERE IS REASONABLE AGREEMENT BETWEEN THE
GLOBAL MODELS ON THE OVERALL SYNOPTIC PATTERN. LATEST GFS SHOWS
PRETTY DEEP MOISTURE BACKING INTO THE SRN FRONT RANGE ON FRIDAY...
BRINGING A RETURN THREAT OF LOCALLY HEAVY RAIN AND POSSIBLY SOME
STRONG STORMS. HAVE BOOSTED POPS SLIGHTLY FOR THIS LATTER PERIOD
TO ACCOUNT FOR GOOD MODEL AGREEMENT AND POTENTIAL FOR HIGH QPF.
ROSE
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 316 AM MDT FRI MAY 30 2014
DISTURBANCE MOVING ACROSS THE REGION WILL COMBINE WITH WIDESPREAD
MOISTURE TO PRODUCE FAIRLY WIDESPREAD SHOWER AND THUNDERSTORM
ACTIVITY ACROSS SOUTHERN COLORADO TODAY AND THIS EVENING. ACTIVITY
WILL DEVELOP OVER THE MOUNTAINS 17Z- 18Z...SPREADING INTO THE SAN
LUIS VALLEY...PALMER DIVIDE AND INTERSTATE 25 CORRIDOR 17Z-20Z.
WILL CARRY VCTS ALL TERMINALS FROM 17Z ONWARD THROUGH ABOUT
01Z...WITH STORMS THEN MOVING EAST OF THE TAF SITES IN THE
EVENING. EXPECT MVFR/BRIEF IFR CONDITIONS UNDER THE STRONGEST
STORMS TODAY.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...ROSE
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
249 AM MDT FRI MAY 30 2014
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 249 AM MDT FRI MAY 30 2014
EARLY MORNING WV IMAGERY AND RAP H5 SHOW REX BLOCK PATTERN IN PLACE
OVER CENTRAL US WITH RIDGE OVER NORTHERN MISSISSIPPI RIVER VALLEY
AND CLOSED LOW OVER SOUTHERN MISSISSIPPI RIVER VALLEY. UPSTREAM
A POSITIVELY TILTED TROUGH EXTENDS FROM WESTERN CANADA AND ALONG
THE WESTERN US COAST WITH SOUTHWEST FLOW EXTENDING FROM THE EASTER
PACIFIC OCEAN ACROSS THE GREAT BASIN AND CENTRAL ROCKIES. A PLUME
OF HIGH WV IS IN PLACE ACROSS THE ROCKIES AND SOUTHERN PLAINS
ORIGINATING MAINLY FROM THE WESTERN GULF OF MEXICO.
ACTIVE PATTERN IS STILL ANTICIPATED THROUGH THIS WEEKEND AS A
SERIES OF SHORTWAVE TROUGHS EMBEDDED WITHIN THE THE SW TRANSLATE
NORTH AND EAST ACROSS THE CENTRAL ROCKIES INTO THE NORTHERN
PLAINS. TRACK WOULD GENERALLY FAVOR LOCATIONS WEST AND NORTH FOR
BETTER THUNDERSTORM COVERAGE...HOWEVER GUIDANCE CONTINUES TO SHOW
GOOD LIFT/MOISTURE/INSTABILITY IN PLACE OVER OUR CWA. HIGHER
TERRAIN IN COLORADO AND SURFACE TROUGH PROGGED TO LINGER AROUND
THE KS/CO STATE LINE WILL BE PRIMARY LOCATION FOR INITIATION FOR
THIS AFTERNOON/TONIGHT AND AGAIN ON SATURDAY. BETTER
LIFT/INSTABILITY IS PROGGED ON SUNDAY/SUNDAY NIGHT ACROSS THE
CWA...WITH SOME GUIDANCE SHOWING A SHIFT IN FLOW TO WEST-EAST AS
BLOCK FINALLY BREAKS DOWN. NOT A LOT OF CERTAINTY REGARDING THE
EXACT EVOLUTION OF THE PATTERN...HOWEVER GUIDANCE CONTINUES TO
SHOW GOOD SUPPORT FOR THUNDERSTORM ACTIVITY ACROSS THE CWA. SHEER
PROFILES GENERALLY WOULDNT SUPPORT MUCH MORE THAN SLOW MOVING
THUNDERSTORM CLUSTERS THROUGH SUNDAY...HOWEVER THERE IS ALSO THE
POTENTIAL FOR FASTER MOVING COLD POOL DOMINANT CLUSTERS (AS NAM IS
GENERALLY SHOWING) WHICH SHOULD TAKE ON MORE OF A EASTERN MOTION.
WITH MODERATE INSTABILITY IN PLACE THERE IS ALSO THE POSSIBLY FOR
A FEW ISOLATED STORMS PRODUCING MARGINALLY SEVERE HAIL...OTHERWISE
IT SEEMS WIND AND LOCALLY HEAVY RAIN WOULD BE THE MAIN CONCERN.
I FELT COMFORTABLE BUMPING UP POPS...ESPECIALLY THIS EVENING AND
SUNDAY/SUNDAY NIGHT IN THE NW WHERE MODELS ARE SHOWING BETTER
CONSISTENCY. DUE TO COMPLICATIONS OF SKY/WX CONFIDENCE IS LOWER ON
TEMPS AND WIND...SO I LEANED TOWARDS A MEAN BLEND WHICH STILL
REFLECTS ABOVE NORMAL TEMPS AND SEASONALLY BREEZY DAYTIME WINDS.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 249 AM MDT FRI MAY 30 2014
AN ACTIVE WEATHER PATTERN IS AHEAD FOR THE TRI STATE AREA IN THE
LONG TERM FORECAST...WITH CHANCES FOR SHOWERS AND THUNDERSTORMS EACH
DAY IN THE PERIOD. MODELS ARE COMING INTO BETTER AGREEMENT REGARDING
THE SHORTWAVE RIDGE DEVELOPING OVER THE HIGH PLAINS MONDAY INTO
TUESDAY WITH SOUTHWESTERLY TO WESTERLY FLOW ALOFT. THE SUBSIDENCE
ALOFT SHOULD KEEP CONDITIONS MOSTLY DRY TUESDAY...HOWEVER WITH
AFTERNOON HIGH TEMPERATURES APPROACHING CONVECTIVE TEMPERATURES OVER
THE REGION...CAP COULD BREAK IN THE WESTERN PORTIONS OF THE FORECAST
AREA IN THE AFTERNOON AND EVENING HOURS TUESDAY.
THE UPPER LEVEL RIDGE WILL BEGIN TO BREAK DOWN WEDNESDAY AS A
SHORTWAVE RIDGE TROUGH CLIPS THE NORTHERN PORTION OF THE AREA FOR
WEDNESDAY. MODELS DIFFER SOMEWHAT IN REGARD TO THE MOISTURE
AVAILABILITY AT THE MID AND UPPER LEVELS FOR WEDNESDAY. WITH UPPER
LEVEL LOW PRESSURE SYSTEM IN PLACE OVER THE WESTERN CONUS...SOME
GUIDANCE SUGGESTS MOISTURE WILL BE SOMEWHAT FUNNELED INTO THE AREA
FROM THE PACIFIC AS UPPER LEVEL PROFILES IN MODEL SOUNDINGS SHOW
AMPLE MOISTURE FOR STORM DEVELOPMENT. IN OTHER INSTANCES...THE
SOUTHWEST FLOW ALOFT WILL TAP DRY DESERT AIR AND BRING PLENTY OF DRY
AIR ALOFT...WHICH COULD POTENTIALLY BRING FIRE WEATHER CONCERNS IF
MIXING TAKES PLACE. JUST LEFT SOME POPS IN THE FORECAST WITH SOME
INSTABILITY PRESENT IN MODEL FORECASTS...BUT CONVECTION REALLY
DEPENDS ON WHETHER THE MOIST OR DRY SOLUTIONS PAN OUT FOR WEDNESDAY.
THE APPROACHING SHORTWAVE WILL PROVIDE PRIME LOCATIONS FOR LIFT OVER
THE AREA THURSDAY AT THE MID AND LOWER LEVELS SOMEWHERE OVER THE
HIGH PLAINS...WHICH WILL BRING STORM DEVELOPMENT WITH BETTER
MOISTURE AVAILABILITY AT THE LOWER AND THE MID LEVELS. BEST LOCATION AT
THE MOMENT SHOULD BE EAST OF US HIGHWAY 83...BUT MODEL AGREEMENT TO
EXACT PLACEMENT OF THE LIFT REMAINS POOR.
TEMPERATURES TO START THE PERIOD WILL BE SLIGHTLY ABOVE AVERAGE
BEFORE A SURFACE COLD FRONT MOVES THROUGH THE AREA WEDNESDAY. COOLER
AIR WILL THEN MOVE INTO THE PLAINS IN THE UPPER 70S...WHICH IS MORE
IN LINE WITH NORMAL TEMPERATURES FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1128 PM MDT THU MAY 29 2014
VFR CONDITIONS ARE EXPECTED FOR MOST IF NOT ALL THE PERIOD. GUSTY
SOUTHEAST WINDS WILL DEVELOP AT KGLD NEAR 18Z. THUNDERSTORMS ARE
EXPECTED TO DEVELOP TO THE WEST OF KGLD DURING THE AFTERNOON AND
THEN LOOK TO AFFECT THE SITE AFTER 00Z. HOWEVER...DETAILS THIS FAR
OUT WITH CONVECTION ARE HARD TO ARRIVE AT. SO AT THIS TIME CHOSE
TO INCLUDE VCTS AT KGLD BEGINNING AT 01Z.
DUE TO THE SLOW MOVEMENT OF THE STORMS EXPECTED IT IS POSSIBLE
THAT STORMS COULD AFFECT THE SITE DURING MOST OF THIS LAST SIX
HOURS. BECAUSE OF THAT SLOW MOVEMENT AND UNCERTAINTY OF HOW FAR
EAST THESE STORMS WILL GET...IT DOES LOOK LIKE AT THIS TIME THAT
THUNDERSTORMS WILL BE NEAR TO OR JUST WEST OF KMCK BY THE END OF
THIS PERIOD. SO CHOSE NOT TO MAKE ANY MENTION OF THUNDERSTORMS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...MK
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
347 AM CDT Fri May 30 2014
.SHORT TERM: (Through Late This Afternoon)
Issued at 342 AM CDT Fri May 30 2014
Isolated showers were occurring from Jerseyville southeast to Salem
IL early this morning with better coverage across southeast MO.
This activity was moving northwestward. The best coverage of
showers and storms this morning may occur across the southern
portion of the forecast area as weak shortwaves continue to rotate
around the persistent upper level low over southern AR and northern
LA. The best chance of showers and thunderstorms will be during the
afternoon hours as the atmosphere destabilizes due to daytime
heating. May see a little better coverage of convection this
afternoon along and just southwest of a weakening backdoor type cold
front moving slowly southwestward into northeast MO and southwest
IL. The latest HRRR model run has the best coverage of
showers/storms early this afternoon southwest of UIN and north of
COU and also southeast of STL. Highs today will be similar to
yesterday and slightly above normal with plenty of mid-high level
cloudiness along with diurnal cumulus clouds late this morning and
this afternoon.
GKS
.LONG TERM: (Tonight through Thursday)
Issued at 342 AM CDT Fri May 30 2014
With broad and slow moving ridge producing a sluggish weather
pattern over the central CONUS, persistence should provide a pretty
good first guess on upcoming sensible weather trends in most areas
heading into the weekend. Ridge axis does work east just a bit
during the weekend, but it still appears that weak disturbances
rotating around the upper low over the Gulf coast region will drift
up the east side of the ridge and into the mid-Mississippi Valley,
interacting with the weakly unstable airmass that is locked over the
area. This should mean a continued a threat of scattered showers and
thunderstorms, primarily during the afternoon and early evening
hours. We`ve used a fairly broad brush on PoPs on both Saturday and
Sunday afternoons/evenings, with the anticipation that any
fine-tuning of precipitation threat will have to wait until the
first period due to the very weak features that will be driving the
convection.
About the only location where we can rule out convection would be
extreme eastern sections of the FA on Saturday. Here, a bit of
drier air backdooring in from the east should stabilize the airmass
while the upper ridge exerts its greatest influence.
Temperatures should also reflect max/min trends of the past few days
and nights, with highs in the 80s and lows in the 60s.
Heading into the new work week, the upper ridge is forecast to
continue a slow eastward drift, which will allow a series of
shortwaves to push into the area as westerlies dip southward and
take on a more zonal look. While exact details are still a bit
sketchy, if this scenario does unfold there should be several good
chances of showers and thunderstorms in the Monday-Thursday time frame,
especially over the northern half of the FA.
With no major changes in the airmass during most of the medium
range temperatures should remain above average, with highs in the
80s and lows in the 60s.
Truett
&&
.AVIATION: (For the 06z TAFs through 06z Friday Night)
Issued at 1131 PM CDT Thu May 29 2014
Upper low continues to spin across Arkansas, sending a steady
fetch of mid and high level clouds northwest across the area.
Otherwise surface wind remain east/southeast. Slight chance of a
shower overnight, with a better chance of some MVFR fog and
stratus developing due to the stagnant airmass and high moisture
content.
Looking for showers and thunderstorms to redevelop by early
afternoon on Friday, but coverage will remain isolated to
scattered so VCTS remains in the forecast.
Specifics for KSTL:
Anticipate some MVFR fog and stratus to develop by 10Z, otherwise
should see improving conditions Friday morning with a renewed
threat of thunderstorms by Friday afternoon.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...CORRECTED
NWS NORTH PLATTE NE
354 AM CDT FRI MAY 30 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CDT FRI MAY 30 2014
TODAY AND TONIGHT...A SUBTROPICAL MOISTURE PLUME FROM THE
REMNANTS OF HURRICANE AMANDA MOVES EAST INTO WRN NEB THIS AFTN.
THE HRRR IS LIGHTING UP THIS AREA WITH SCATTERED TSTMS FROM 19Z
ON. THIS MAY BE AN HOUR OR TWO TOO FAST. MEANWHILE THE RAP SHOWS
K INDICES OVER 40C AND A STORM MOTION AROUND 200 DEGREES AT 8
KTS. LOCALLY HEAVY RAINFALL WOULD APPEAR POSSIBLE ACROSS SHERIDAN
COUNTY. 3 HOUR FLOOD GUIDANCE IS AROUND 2 INCHES SUGGESTING SOME
POTENTIAL FOR LOCAL FLOODING. NO FLOOD WATCH WILL BE ISSUED WITH
THIS FORECAST BUT HEAVY RAIN WORDING IS IN PLACE IN THIS GENERAL
AREA.
THE MOISTURE PLUME ADVANCES EAST A BIT OVERNIGHT BUT MORE
IMPORTANT THE SFC FRONT SAGS SOUTH AND EAST TO NEAR KVTN-KIML AND
MOISTURE WILL POOL BEHIND THIS FRONT IN CONJUNCTION WITH THE
MOISTURE PLUME ALOFT. THUS TSTM COVERAGE SHOULD INCREASE THIS
AFTN AND REMAIN FAIRLY ROBUST OVERNIGHT ACROSS WRN NEB.
THE SEVERE WEATHER CONCERN COVERS MAINLY SHERIDAN COUNTY WHERE
BULK SHEAR INCREASES TO AROUND 30 KTS. THE RAP AND NAM SUGGESTED
THE BETTER CHANCE FOR SEVERE STORMS WOULD BE JUST EAST OF THE
BLACK HILLS AND THEN SOUTH INTO SHANNON COUNTY SD.
THE TEMPERATURE FORECAST IS LITTLE CHANGED FROM THE PREVIOUS
FORECAST. SOUTHEAST WINDS ARE EXPECTED TO LIMIT VERTICAL MIXING
AND HOLD HIGHS DOWN IN THE 80S AHEAD OF THE FRONT. THE RAP AND
HRRR SHOW A DRIER SOUTHEAST FLOW WITH DEEPER MIXING AND HIGHS
NEAR 90 AND THESE MODELS BLENDED WITH THE REST PRODUCES A FCST
FOR HIGHS IN THE UPPER 80S TODAY.
LOWS TONIGHT FALL INTO THE LOWER 60S AHEAD OF THE FRONT WITH 50S
BEHIND THE FRONT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 352 AM CDT FRI MAY 30 2014
UPPER LEVEL RIDGE OF HIGH PRESSURE SHIFTS TO THE EAST COAST BY
THE END OF THE WEEKEND AS A TROUGH PUSHES ACROSS THE NORTHERN
ROCKIES. A SECOND TROUGH MOVES ACROSS THE ROCKIES AGAIN BY
MIDWEEK. THIS WILL RESULT IN AN ACTIVE WEEKEND WITH UNSETTLED
WEATHER CONTINUING INTO MID WEEK.
SEVERAL MID LEVEL DISTURBANCES WILL SLIDE ACROSS THE AREA WITH
STORMS EXPECTED TO FIRE WITH EACH WAVE. ON SATURDAY A WAVE WILL
BE CROSSING THE AREA DURING THE DAY WITH A SECONDARY WAVE
ENTERING FROM THE WEST LATE. A BRIEF DRY SLOW WILL ALLOW FOR A
FEW BREAKS IN THE CLOUDS DURING THE DAY. THE SECONDARY WAVE WILL
ARRIVE LATE WITH A LOW LEVEL JET OF 30 TO 35 KTS TO SUSTAIN
ACTIVITY OVERNIGHT.
POSSIBLE BREAK IN ACTION SUNDAY MORNING AS THE ATMOSPHERE GETS
READY FOR THE NEXT WAVE LATER IN THE DAY. FLOW BECOMES A LITTLE
MORE ZONAL...COMPARED TO THE SW FLOW FOR SATURDAY. MOISTURE IS
GOOD WITH PWATS INCREASING TO 1.50 TO AS HIGH AS 1.75 AHEAD OF
THE WAVE. THE GOOD MOISTURE WILL COMBINE WITH THE ADDED SHEAR
FROM THE MID LEVEL FLOW BEING A LITTLE MORE WESTERLY AND TEMPS
INTO THE 80S WITH EARLY SUN. THIS SETS THE STAGE FOR STRONG TO
SEVERE THUNDERSTORMS TO DEVELOP. MODELS STRUGGLING WITH THE
PLACEMENT OF THE SURFACE BOUNDARY/LOW...WITH A GENERALLY
CONSENSUS OF THE LOW TO BE IN EASTERN COLORADO OR WESTERN
KANSAS...SW OF THE CWA. THE SEVERE WEATHER WILL NOT BE THE ONLY
CONCERN...AS STORMS SHOULD BE GOOD RAIN PRODUCERS WITH LOCALLY
HEAVY RAIN.
SUNDAY NIGHT INTO MONDAY WILL BE A BRIEF BREAK IN THE ACTION AS
THE NEXT WAVE ARRIVES MONDAY AFTERNOON INTO MONDAY NIGHT. THE
TRAIN OF WAVES CONTINUES AS THE NEXT UPPER LEVEL TROUGH PUSHES
ACROSS THE ROCKIES. WHILE POPS ARE IN EVERY PERIOD IN THE
EXTENDED...THERE SHOULD BE SOME BREAKS IN THE ACTION...AND EVEN
SOME CLEARING. ALTHOUGH THE BREAKS MAYBE SHORT LIVED AND TIMING
THEM IS DIFFICULT THIS FAR OUT. AS FOR TEMPS...MORE SEASONAL
TEMPS WITH HIGHS MID 70S TO THE LOWER 80S...WHICH IS CLOSE TO
NORMAL FOR THE FIRST WEEK OF JUNE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1221 AM CDT FRI MAY 30 2014
OVER THE NEXT 18 HOURS...EXPECT VFR CONDS AT BOTH THE KLBF AND
KVTN TERMINALS WITH SOME HIGH CLOUDINESS AON 20000 FT LIKELY
DURING THE LATE AFTERNOON HOURS FRIDAY. BY FRIDAY EVENING...THE
THREAT FOR THUNDERSTORMS WILL INCREASE AS AN UPPER LEVEL TROUGH OF
LOW PRESSURE LIFTS EAST INTO WESTERN AND PORTIONS OF NORTH CENTRAL
NEBRASKA. THUNDERSTORMS WILL APPROACH THE KVTN TERMINAL BY MID
EVENING...AND THE KLBF TERMINAL BY LATE EVENING FRIDAY. CIGS IN
ASSOCIATION WITH THE STORMS WILL BE AROUND 5000 FT AGL. VISBYS MAY
DROP DOWN TO 3SM AT THE KVTN TERMINAL. ALONG WITH REDUCED
VISBYS...SOME GUSTY ERRATIC WINDS MAY OCCUR IN THE VICINITY OF
STORMS. WINDS OVER THE NEXT 18 HOURS WILL GENERALLY BE FROM THE
SOUTHEAST OR SOUTH AT 10 TO 20 KTS. A SHIFT TO THE EAST AND
NORTHEAST WILL OCCUR DURING THE LATE EVENING HOURS FRIDAY WITH
SPEEDS AROUND 10 KTS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
352 AM CDT FRI MAY 30 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CDT FRI MAY 30 2014
TODAY AND TONIGHT...A SUBTROPICAL MOISTURE PLUME FROM THE
REMNANTS OF HURRICANE AMANDA MOVES EAST INTO WRN NEB THIS AFTN.
THE HRRR IS LIGHTING UP THIS AREA WITH SCATTERED TSTMS FROM 19Z
ON. THIS MAY BE AN HOUR OR TWO TOO FAST. MEANWHILE THE RAP SHOWS
K INDICES OVER 40C AND A STORM MOTION AROUND 200 DEGREES AT 8
KTS. LOCALLY HEAVY RAINFALL WOULD APPEAR POSSIBLE ACROSS SHERIDAN
COUNTY. 3 HOUR FLOOD GUIDANCE IS AROUND 2 INCHES SUGGESTING SOME
POTENTIAL FOR LOCAL FLOODING. NO FLOOD WATCH WILL BE ISSUED WITH
THIS FORECAST BUT HEAVY RAIN WORDING IS IN PLACE IN THIS GENERAL
AREA.
THE MOISTURE PLUME ADVANCES EAST A BIT OVERNIGHT BUT MORE
IMPORTANT THE SFC FRONT SAGS SOUTH AND EAST TO NEAR KVTN-KIML AND
MOISTURE WILL POOL BEHIND THIS FRONT IN CONJUNCTION WITH THE
MOISTURE PLUME ALOFT. THUS TSTM COVERAGE SHOULD INCREASE THIS
AFTN AND REMAIN FAIRLY ROBUST OVERNIGHT ACROSS WRN NEB.
THE SEVERE WEATHER CONCERN COVERS MAINLY SHERIDAN COUNTY WHERE
BULK SHEAR INCREASES TO AROUND 30 KTS. THE RAP AND NAM SUGGESTED
THE BETTER CHANCE FOR SEVERE STORMS WOULD BE JUST EAST OF THE
BLACK HILLS AND THEN SOUTH INTO SHANNON COUNTY SD.
THE TEMPERATURE FORECAST IS LITTLE CHANGED FROM THE PREVIOUS
FORECAST. SOUTHEAST WINDS ARE EXPECTED TO LIMIT VERTICAL MIXING
AND HOLD HIGHS DOWN IN THE 80S AHEAD OF THE FRONT. THE RAP AND
HRRR SHOW A DRIER SOUTHEAST FLOW WITH DEEPER MIXING AND HIGHS
NEAR 90 AND THESE MODELS BLENDED WITH THE REST PRODUCES A FCST
FOR HIGHS IN THE UPPER 80S TODAY.
LOWS TONIGHT FALL INTO THE LOWER 60S AHEAD OF THE FRONT WITH 50S
BEHIND THE FRONT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 352 AM CDT FRI MAY 30 2014
UPPER LEVEL RIDGE OF HIGH PRESSURE SHIFTS TO THE EAST COAST BY
THE END OF THE WEEKEND AS A TROUGH PUSHES ACROSS THE NORTHERN
ROCKIES. A SECOND TROUGH MOVES ACROSS THE ROCKIES AGAIN BY
MIDWEEK. THIS WILL RESULT IN AN ACTIVE WEEKEND WITH UNSETTLED
WEATHER CONTINUING INTO MID WEEK.
SEVERAL MID LEVEL DISTURBANCES WILL SLIDE ACROSS THE AREA WITH
STORMS EXPECTED TO FIRE WITH EACH WAVE. ON SATURDAY A WAVE WILL
BE CROSSING THE AREA DURING THE DAY WITH A SECONDARY WAVE
ENTERING FROM THE WEST LATE. A BRIEF DRY SLOW WILL ALLOW FOR A
FEW BREAKS IN THE CLOUDS DURING THE DAY. THE SECONDARY WAVE WILL
ARRIVE LATE WITH A LOW LEVEL JET OF 30 TO 35 KTS TO SUSTAIN
ACTIVITY OVERNIGHT.
POSSIBLE BREAK IN ACTION SUNDAY MORNING AS THE ATMOSPHERE GETS
READY FOR THE NEXT WAVE LATER IN THE DAY. FLOW BECOMES A LITTLE
MORE ZONAL...COMPARED TO THE SW FLOW FOR SATURDAY. MOISTURE IS
GOOD WITH PWATS INCREASING TO 1.50 TO AS HIGH AS 1.75 AHEAD OF
THE WAVE. THE GOOD MOISTURE WILL COMBINE WITH THE ADDED SHEAR
FROM THE MID LEVEL FLOW BEING A LITTLE MORE WESTERLY AND TEMPS
INTO THE 80S WITH EARLY SUN. THIS SETS THE STAGE FOR STRONG TO
SEVERE THUNDERSTORMS TO DEVELOP. MODELS STRUGGLING WITH THE
PLACEMENT OF THE SURFACE BOUNDARY/LOW...WITH A GENERALLY
CONSENSUS OF THE LOW TO BE IN EASTERN COLORADO OR WESTERN
KANSAS...SW OF THE CWA. THE SEVERE WEATHER WILL NOT BE THE ONLY
CONCERN...AS STORMS SHOULD BE GOOD RAIN PRODUCERS WITH LOCALLY
HEAVY RAIN.
SUNDAY NIGHT INTO MONDAY WILL BE A BRIEF BREAK IN THE ACTION AS
THE NEXT WAVE ARRIVES MONDAY AFTERNOON INTO MONDAY NIGHT. THE
TRAIN OF WAVES CONTINUES AS THE NEXT UPPER LEVEL TROUGH PUSHES
ACROSS THE ROCKIES. WHILE POPS ARE IN EVERY PERIOD IN THE
EXTENDED...THERE SHOULD BE SOME BREAKS IN THE ACTION...AND EVEN
SOME CLEARING. ALTHOUGH THE BREAKS MAYBE SHORT LIVED AND TIMING
THEM IS DIFFICULT THIS FAR OUT. AS FOR TEMPS...MORE SEASONAL
TEMPS WITH HIGHS AROUND 80 TO THE MID 80S...WHICH IS CLOSE TO OR
SLIGHTLY ABOVE NORMAL FOR THE FIRST WEEK OF JUNE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1221 AM CDT FRI MAY 30 2014
OVER THE NEXT 18 HOURS...EXPECT VFR CONDS AT BOTH THE KLBF AND
KVTN TERMINALS WITH SOME HIGH CLOUDINESS AON 20000 FT LIKELY
DURING THE LATE AFTERNOON HOURS FRIDAY. BY FRIDAY EVENING...THE
THREAT FOR THUNDERSTORMS WILL INCREASE AS AN UPPER LEVEL TROUGH OF
LOW PRESSURE LIFTS EAST INTO WESTERN AND PORTIONS OF NORTH CENTRAL
NEBRASKA. THUNDERSTORMS WILL APPROACH THE KVTN TERMINAL BY MID
EVENING...AND THE KLBF TERMINAL BY LATE EVENING FRIDAY. CIGS IN
ASSOCIATION WITH THE STORMS WILL BE AROUND 5000 FT AGL. VISBYS MAY
DROP DOWN TO 3SM AT THE KVTN TERMINAL. ALONG WITH REDUCED
VISBYS...SOME GUSTY ERRATIC WINDS MAY OCCUR IN THE VICINITY OF
STORMS. WINDS OVER THE NEXT 18 HOURS WILL GENERALLY BE FROM THE
SOUTHEAST OR SOUTH AT 10 TO 20 KTS. A SHIFT TO THE EAST AND
NORTHEAST WILL OCCUR DURING THE LATE EVENING HOURS FRIDAY WITH
SPEEDS AROUND 10 KTS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1258 AM CDT FRI MAY 30 2014
.UPDATE...
ISSUED AT 1258 AM CDT FRI MAY 30 2014
ONLY MINOR CHANGES WERE MADE FOR THIS UPDATE. A LINE OF POST-FRONTAL SHOWERS
AND THUNDERSTORMS CONTINUE ACROSS CENTRAL NORTH DAKOTA. UPDATED
POPS TO REFLECT THE LATEST TRENDS WITH THIS LINE. THE MAIN CONCERN
WITH THIS LINE IS HEAVY RAIN. RADAR INDICATES WIDESPREAD 0.5 TO 1
INCH AMOUNTS. VERY HEAVY RAIN RATES OF 1 INCH AN HOUR OR GREATER
COULD LEAD TO QUICK RISES IN LOCAL CREEKS AND TRIBUTARIES AND
PONDING ON ROADWAYS. THANKFULLY THE FRONT CONTINUES TO PROPAGATE AT
A QUICK ENOUGH PACE THAT MAJOR FLOOD RELATED ISSUES AREN`T
EXPECTED.
UPDATE ISSUED AT 945 PM CDT THU MAY 29 2014
WILL ALLOW SEVERE THUNDERSTORM WATCH TO EXPIRE AS THE LAST FEW
STRONG/SEVERE STORMS HAVE WEAKENED. OTHERWISE MADE SOME ADDITIONAL
ADJUSTMENTS TO DECREASE POPS FARTHER EAST WHERE MODELS ARE INDICATING
LESS ACTIVITY...ESPECIALLY SOUTHEAST. COLD FRONT CONTINUES TO PUSH
SLOWLY EASTWARD WITH ONGOING CONVECTION OCCURRING BEHIND FRONT.
WINDS HAVE SHIFTED TO NW AT KMOT AT 0130Z AND FRONT IS NEARING
KBIS.
UPDATE ISSUED AT 658 PM CDT THU MAY 29 2014
CANCELED WIND ADVISORY AS WINDS HAVE DIMINISHED BELOW ADVISORY
LIMITS. TRIMMED WESTERN-MOST COUNTIES FROM SEVERE THUNDERSTORM
WATCH...ALTHOUGH SOME POST FRONTAL DEVELOPMENT OCCURRING ACROSS
EASTERN MCKENZIE SOUTHWARD INTO BILLINGS COUNTY WHERE LESS CAPE IS
AVAILABLE BUT STRONGER SHEAR IS IN PLACE. ADJUSTED POPS TO ACCOUNT
FOR LATEST TRENDS AND FOLLOWED HRRR WHICH SEEMED TO HANDLE
CONVECTION ADEQUATELY.
UPDATE ISSUED AT 428 PM CDT THU MAY 29 2014
SEVERE THUNDERSTORM WATCH IN EFFECT UNTIL 03Z FOR MUCH OF CENTRAL
AND WESTERN ND. CELLS BEGINNING TO DEVELOP ACROSS SOUTHWEST ND ALONG
COLD FRONT THAT IS SLOWLY MOVING EASTWARD. SPC MESO ANALYSIS PAGE
CONTINUES TO SHOW ABUNDANT INSTABILITY WITH CAPE OF 2000-3000 J/KG
ALONG AND AHEAD OF THE FRONT ALTHOUGH BEST SHEAR LAGS INSTABILITY
AXIS SOMEWHAT. EXPECTING TO BE ENOUGH OVERLAP OF SHEAR/INSTABILITY
TO SUPPORT MAINLY WIND/HAIL THREAT WITH STORMS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 230 PM CDT THU MAY 29 2014
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE THUNDERSTORMS
DEVELOPING THIS AFTERNOON/EARLY EVENING...CONTINUING AND SLOWLY
MOVING EAST TONIGHT INTO FRIDAY. A FEW SEVERE STORMS WILL BE
POSSIBLE. DETAILS BELOW.
CURRENTLY...UPPER LEVEL RIDGE AXIS ACROSS THE EASTERN DAKOTAS WITH
A STRONG S/WV TROUGH/CLOSED LOW LIFTING NORTHEAST INTO WESTERN
SASKATCHEWAN. THIS PUTS SOUTHWESTERLY FLOW ALOFT ACROSS THE
MONTANA ROCKIES AND WESTERN DAKOTAS. AT THE SURFACE... TROUGH OF
LOW PRESSURE JUST NOW CROSSING THE MONTANA/NORTH DAKOTA BORDER
WITH WINDS SHIFTING TO WESTERLY AT SIDNEY AND BAKER MONTANA. WINDS
HAVE REMAINED RATHER GUSTY EAST OF THE TROUGH ACROSS CENTRAL NORTH
DAKOTA WHERE GUSTS HAVE RANGED FROM 40 TO JUST OVER 50 MPH FROM
MORTON AND BURLEIGH COUNTIES NORTH AND NORTHEAST INTO NORTH
CENTRAL PORTIONS OF THE STATE. WILL MAINTAIN THE WIND ADVISORY AS
IS...ISSUED ABOUT AN HOUR OR TWO AGO THROUGH THE AFTERNOON HOURS.
MODELS IN GOOD AGREEMENT LIFTING THE STRONGER MID LEVEL WINDS INTO
CANADA BY 00Z...AS WELL AS RELAXING THE PRESSURE GRADIENT WITH
TIME.
HIGH RESOLUTION/SHORT TERM MODELS STILL IN GREAT AGREEMENT THAT
THE SFC TROUGH AXIS/COLD FRONTAL BOUNDARY WILL BE THE FOCUS FOR
CONVECTION MID TO LATE THIS AFTERNOON/EARLY EVENING AS THE MID
LEVEL CAPPING INVERSION ERODES WITH THE APPROACH OF AN UPPER
LEVEL SPEED MAX LIFTING NORTH AND EAST ACROSS MONTANA. INITIAL
DEVELOPMENT STILL A BIT UNCERTAIN...BUT MODELS IN GENERAL
AGREEMENT THUNDERSTORMS DEVELOPING ACROSS WESTERN SOUTH DAKOTA
FIRST PERHAPS OVER THE BLACK HILLS BY 20-21Z...THEN
NORTH/NORTHEAST ALONG THE FRONTAL BOUNDARY THEREAFTER.
THUNDERSTORMS THEN CONTINUE TO DEVELOP/MOVE NORTHEAST ALONG THE
BOUNDARY TONIGHT...WITH STORM COVERAGE INCREASING SLOWLY EAST
WITH THE FRONTAL MOVEMENT.
THE LATEST SPC DAY 1 OUTLOOK NOW HAS A SLIGHT RISK AREA ALONG A
NARROW AXIS ALONG THE FRONT...INCLUDING SOUTHWEST AND CENTRAL
PORTIONS OF NORTH DAKOTA...MAINLY DURING THE DAYLIGHT HOURS WITH
THE SEVERE THREAT DIMINISHING WITH DARK. MLCAPE VALUES ARE RISING
INTO THE 1500 TO 2500 J/KG RANGE NEAR THE BOUNDARY WITH EFFECTIVE
SHEAR OF 25 TO 30 KTS ALONG THE BOUNDARY. BETTER AND MORE
SUPPORTIVE SHEAR RESIDES WEST OF THE FRONT. WILL MENTION THE
POSSIBILITY OF SEVERE WEATHER IN THE HAZARDOUS WEATHER
OUTLOOK...ALTHOUGH SHOULD NOTE THE BEST CAPE WILL BE DISPLACED
FROM THE BEST SHEAR. STORM MOVEMENT SHOULD BE ROBUST WITH MEAN
STORM MOTION 30-40 KTS TO THE NORTHEAST. HOWEVER...WITH THE SLOW
EASTWARD MOVEMENT OF THE FRONT...AND STORMS EXPECTED TO REDEVELOP
ALONG THE FRONT...TRAINING THUNDERSTORMS WILL BE POSSIBILITY
ENHANCING THE POTENTIAL FOR HEAVY RAINFALL.
SFC TROUGH SLOWLY MOVES EAST FRIDAY...BECOMING QUASI-STATIONARY
OVER THE SOUTH CENTRAL EAST INTO THE JAMES AND RED RIVER VALLEY
REGIONS. THUS ANOTHER ROUND OF STRONG TO SEVERE STORMS WITH HEAVY
RAIN LIKELY ALONG TO AHEAD OF THE SFC BOUNDARY. WILL MAINTAIN A
DRY FORECAST ACROSS THE NORTHWEST QUARTER OF ND FRIDAY WITH HIGH
PRESSURE AND A STABLE AIRMASS DEVELOPING SOUTH AND EAST FROM
CANADA IN THE WAKE OF THE TROUGH.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 230 PM CDT THU MAY 29 2014
AN ACTIVE AND WET PATTERN IS STILL IN STORE ACROSS WESTERN AND
CENTRAL NORTH DAKOTA IN THE LONG TERM PERIOD.
FRIDAY EVENING...A NEARLY STATIONARY SURFACE FRONTAL BOUNDARY IS
FORECAST TO EXTEND FROM NORTHWESTERN MINNESOTA ACROSS SOUTHEASTERN
NORTH DAKOTA - INCLUDING THE JAMES RIVER VALLEY - AND INTO CENTRAL
SOUTH DAKOTA. THERE SHOULD BE ONGOING SHOWERS AND THUNDERSTORMS FROM
THE DAYTIME FRIDAY PERIOD. THIS SHOULD CONTINUE A PERIOD OF HEAVY
RAIN FRIDAY NIGHT INTO SATURDAY MORNING IN THE JAMES RIVER BASIN
EXTENDING WESTWARD INTO SOUTH CENTRAL NORTH DAKOTA IN THE SOUTHERN
MISSOURI VALLEY OF NORTH DAKOTA...SOUTH OF LAKE SAKAKAWEA.
AT UPPER LEVELS...A SEMI-PERMANENT TROUGH OVER THE ROCKIES WILL KEEP
A SOUTHWESTERLY FLOW ALOFT OVER NORTH DAKOTA. A SERIES OF UPPER
LEVEL ENERGY IMPULSES MOVING NORTHEASTWARD THROUGH THE FLOW FRIDAY
THROUGH SATURDAY MORNING WILL ENHANCE THE PRECIPITATION ALONG THE
SURFACE BOUNDARY.
THERE APPEARS TO BE A BREAK IN THE UPPER LEVEL ENERGY IMPULSES
SATURDAY LATE MORNING/EARLY AFTERNOON...BUT A REINFORCEMENT OF
IMPULSES ARRIVES SATURDAY AFTERNOON IN THE WEST...AND CONTINUES
THROUGH SUNDAY NIGHT.
HEAVY RAIN IS LOOKING LIKELY FROM BISMARCK TO CARRINGTON AND SOUTH
FRIDAY THROUGH THE SUNDAY NIGHT TIME FRAME.
THE MODELS DIFFER ON THE CHARACTER OF THE UPPER LEVEL ENERGY -
WHETHER CONTINUED TROUGHING OR A CLOSED LOW OVER THE STATE - BUT
REGARDLESS THE CHANCE OF THUNDERSTORMS CONTINUES INTO EARLY NEXT
WEEK. THE MODELS DIFFER ON TIMING OF UPPER LEVEL IMPULSES BY
EARLY/MID WEEK NEXT WEEK...SO KEPT THE MODEL CONSENSUS WITH ISOLATED
TO SCATTERED SHOWERS AND THUNDERSTORMS THROUGH MID-WEEK.
BEST CHANCES OF RAIN IN THE LONG TERM IS FRIDAY NIGHT THROUGH SUNDAY
NIGHT...BUT CHANCES CONTINUE IN EACH PERIOD OF THE FORECAST THROUGH
NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1258 AM CDT FRI MAY 30 2014
SHOWERS AND THUNDERSTORMS CONTINUE ACROSS CENTRAL NORTH DAKOTA AS
A COLD FRONT MOVES EASTWARD ACROSS THE STATE. WINDS WILL TURN
WEST/NORTHWEST BEHIND THE FRONT. VCSH/VCTS FOR EARLY FRIDAY
MORNING AT KMOT/KBIS AND THROUGH THE LATE MORNING HOURS FOR KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AJ
SHORT TERM...NH
LONG TERM...JV
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
115 AM EDT FRI MAY 30 2014
.SYNOPSIS...
HIGH PRESSURE OVER EASTERN CANADA WILL BUILD SOUTH ACROSS THE
EASTERN GREAT LAKES THROUGH SATURDAY. THE HIGH WILL THEN SHIFT
OFF THE MID ATLANTIC COAST BY MONDAY. A COLD FRONT OR SERIES OF
COLD FRONTS FROM CANADA IS EXPECTED TO DROP SOUTHEAST ACROSS THE
AREA NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
PLENTY OF THIN CIRRUS MOVING ACROSS THE AREA. MADE JUST A FEW
MINOR CHANGES TO THE LOWS. WATCHING THE STRATUS OVER WRN NY AND
WRN PA...WHETHER IT COULD SNEAK INTO ERIE AND CRAWFORD COUNTIES IN
PA. THE HRRR MODEL IS TRYING TO INDICATE THAT SOME DENSE FOG MAY
DEVELOP OVER NW OH...ADDED PATCHY FOG TO THAT AREA.
PREVIOUS DISCUSSION...
SOME HIGH CLOUDS...MOSTLY THIN...ARE SPILLING OVER TOP OF THE
RIDGE TONIGHT. THESE SHOULD FADE AWAY FRIDAY MORNING AS THE RIDGE
ALOFT CONTINUES TO BUILD. NUDGED THE LOW TEMPS DOWN A FEW DEGREES
IN THE NORMALLY COLDER SPOTS...WHERE MINS WILL LIKELY DROP INTO
THE UPPER 40S...PERHAPS EVEN A FEW MID 40S...AS THE AIR MASS DRIES
OUT. OTHERWISE LOWS MOSTLY DOWN TOWARD 50...A LITTLE WARMER AT THE
LAKE ERIE LAKESHORE. FOG WILL BE LIMITED TO SHELTERED AREAS AND
COOL SPOTS AND PROBABLY NOT GET DENSE. NIGHTS ARE SHORT THIS TIME
OF YEAR. THE NNE WINDS WILL REMAIN UP A BIT OVERNIGHT...3-6
KNOTS...EXCEPT A BIT STRONGER AT THE LAKESHORE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
HIGH PRESSURE WILL INCREASE ITS INFLUENCE INTO SATURDAY BEFORE
SHIFTING TO THE EAST COAST ON SUNDAY. THIS SHOULD MAKE FOR A
PLEASANT WEEKEND WITH TEMPERATURES GRADUALLY WARMING INTO SUNDAY.
HIGHS AT MOST LOCATIONS WILL WARM TO WITHIN A FEW DEGREES OF 80.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
SUFFICIENT MOISTURE SHOULD BE OVER THE AREA TO SUPPORT RAIN ON MON
BUT THE QUESTION IS WHAT WILL BE THE TRIGGER. THE WARM FRONT IS
SHOWN TO BE NORTH OF THE AREA. MEX GUIDANCE HAS SOME AREAS ON MON
MARGINALLY INTO THE LIKELY CATEGORY. PREFER TO STAY WITH JUST CHANCE
POPS DUE TO THE LACK OF A FOCUSING MECHANISM.
AN UPPER TROUGH WORKS EAST ACROSS THE NORTHERN PART OF THE LAKES MON
NIGHT THRU WED. SOME MODELS SHOW A DRY PUNCH ARRIVING FROM THE WEST
ON TUE BUT FOR NOW WILL MAINTAIN CHANCE POPS FOR SHRA/TSRA AS THE
FRONT TRAILING THE SURFACE LOW MAY STALL OVER OR NEAR THE SOUTHERN
PART OF THE CWA WED NIGHT AND THU.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
DEW POINTS REMAIN LOW ACROSS THE REGION AS THE COLD FRONT CONTINUES
TO PUSH EVEN FURTHER SOUTH OF THE AREA TO THE OHIO RIVER.
HOWEVER...IT LOOKS LIKE TEMPERATURES WILL REACH THE CROSSOVER
TEMPERATURES BASED ON THURSDAY AFTERNOON OBSERVATIONS. THIS COULD
SUPPORT SOME MVFR FOG WITH THE BEST CHANCES AT TOL/FDY/AKR/MFD. SOME
HIGH CIRRUS COMING AROUND THE TOP OF THE RIDGE OVER MICHIGAN AND
INTO NORTHERN OHIO SHOULDN`T LIMIT COOLING. CONCERNED ABOUT STRATUS
DEVELOPING IN NY/PA AND SPREADING SW INTO PBZ AREA. THIS STRATUS
COULD CLIP YNG AREA WITH IFR CONDITIONS THROUGH SUNRISE. MODEL
GUIDANCE NOT PICKING UP ON THIS ACTIVITY THIS FAR WEST...BUT BASED
ON SATELLITE TRENDS WILL INTRODUCE BKN 900-2000 FT CEILINGS. DRY AIR
ADVECTION IN MIXING FRIDAY WILL LIFT ANY FOG/STRATUS BY MID MORNING.
VFR WITH LIGHT NORTHEAST WIND UNDER HIGH PRESSURE REMAINDER OF
FRIDAY.
.OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/...
GENERAL VFR IS EXPECTED THIS WEEKEND AS HIGH PRESSURE REMAINS THE
DOMINANT FEATURE. SHOWERS AND THUNDERSTORMS POSSIBLY EARLY NEXT
WEEK.
&&
.MARINE...
NE WINDS WILL DIMINISH A LITTLE MORE WITH SUNSET THEN STAY FAIRLY
LIGHT THRU SAT. THE HIGH SHIFTS EAST OF THE LAKES FOR SUN SO WINDS
SHOULD TURN SE THEN SOUTH TO SW FOR MON WHILE INCREASING TO 10 TO 15
KNOTS WHICH LOOK TO CONTINUE ON TUE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...KIELTYKA/KOSARIK
SHORT TERM...MULLEN
LONG TERM...ADAMS
AVIATION...LOMBARDY
MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1236 AM EDT FRI MAY 30 2014
.SYNOPSIS...
HIGH PRESSURE OVER EASTERN CANADA WILL BUILD SOUTH ACROSS THE
EASTERN GREAT LAKES THROUGH SATURDAY. THE HIGH WILL THEN SHIFT
OFF THE MID ATLANTIC COAST BY MONDAY. A COLD FRONT OR SERIES OF
COLD FRONTS FROM CANADA IS EXPECTED TO DROP SOUTHEAST ACROSS THE
AREA NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
PLENTY OF THIN CIRRUS MOVING ACROSS THE AREA. MADE JUST A FEW
MINOR CHANGES TO THE LOWS. WATCHING THE STRATUS OVER WRN NY AND
WRN PA...WHETHER IT COULD SNEAK INTO ERIE AND CRAWFORD COUNTIES IN
PA. THE HRRR MODEL IS TRYING TO INDICATE THAT SOME DENSE FOG MAY
DEVELOP OVER NW OH...ADDED PATCHY FOG TO THAT AREA.
PREVIOUS DISCUSSION...
SOME HIGH CLOUDS...MOSTLY THIN...ARE SPILLING OVER TOP OF THE
RIDGE TONIGHT. THESE SHOULD FADE AWAY FRIDAY MORNING AS THE RIDGE
ALOFT CONTINUES TO BUILD. NUDGED THE LOW TEMPS DOWN A FEW DEGREES
IN THE NORMALLY COLDER SPOTS...WHERE MINS WILL LIKELY DROP INTO
THE UPPER 40S...PERHAPS EVEN A FEW MID 40S...AS THE AIR MASS DRIES
OUT. OTHERWISE LOWS MOSTLY DOWN TOWARD 50...A LITTLE WARMER AT THE
LAKE ERIE LAKESHORE. FOG WILL BE LIMITED TO SHELTERED AREAS AND
COOL SPOTS AND PROBABLY NOT GET DENSE. NIGHTS ARE SHORT THIS TIME
OF YEAR. THE NNE WINDS WILL REMAIN UP A BIT OVERNIGHT...3-6
KNOTS...EXCEPT A BIT STRONGER AT THE LAKESHORE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
HIGH PRESSURE WILL INCREASE ITS INFLUENCE INTO SATURDAY BEFORE
SHIFTING TO THE EAST COAST ON SUNDAY. THIS SHOULD MAKE FOR A
PLEASANT WEEKEND WITH TEMPERATURES GRADUALLY WARMING INTO SUNDAY.
HIGHS AT MOST LOCATIONS WILL WARM TO WITHIN A FEW DEGREES OF 80.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
SUFFICIENT MOISTURE SHOULD BE OVER THE AREA TO SUPPORT RAIN ON MON
BUT THE QUESTION IS WHAT WILL BE THE TRIGGER. THE WARM FRONT IS
SHOWN TO BE NORTH OF THE AREA. MEX GUIDANCE HAS SOME AREAS ON MON
MARGINALLY INTO THE LIKELY CATEGORY. PREFER TO STAY WITH JUST CHANCE
POPS DUE TO THE LACK OF A FOCUSING MECHANISM.
AN UPPER TROUGH WORKS EAST ACROSS THE NORTHERN PART OF THE LAKES MON
NIGHT THRU WED. SOME MODELS SHOW A DRY PUNCH ARRIVING FROM THE WEST
ON TUE BUT FOR NOW WILL MAINTAIN CHANCE POPS FOR SHRA/TSRA AS THE
FRONT TRAILING THE SURFACE LOW MAY STALL OVER OR NEAR THE SOUTHERN
PART OF THE CWA WED NIGHT AND THU.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL BE THE DOMINATING WEATHER FEATURE ACROSS THE
FORECAST AREA OVERNIGHT AND FRIDAY. TEMPERATURES ARE EXPECTED TO
COOL DOWN NEAR THE DEW POINT AT YOUNGSTOWN AND COULD CAUSE SOME MVFR
FOG TO DEVELOP. OTHERWISE...REST OF THE AREA SHOULD REMAIN VFR IN
THE VISIBILITY. MAINLY CIRRUS CLOUDS EXPECTED ACROSS THE AREA
OVERNIGHT AND CLEAR FRIDAY.
.OUTLOOK...MAINLY VFR.
&&
.MARINE...
NE WINDS WILL DIMINISH A LITTLE MORE WITH SUNSET THEN STAY FAIRLY
LIGHT THRU SAT. THE HIGH SHIFTS EAST OF THE LAKES FOR SUN SO WINDS
SHOULD TURN SE THEN SOUTH TO SW FOR MON WHILE INCREASING TO 10 TO 15
KNOTS WHICH LOOK TO CONTINUE ON TUE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...KIELTYKA/KOSARIK
SHORT TERM...MULLEN
LONG TERM...ADAMS
AVIATION...LOMBARDY
MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
212 AM EDT FRI MAY 30 2014
.SYNOPSIS...
A BACKDOOR COLD FRONT WILL SLOWLY CROSS THE FORECAST AREA FROM THE
NORTHEAST THROUGH FRIDAY NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE
NORTHEAST THIS WEEKEND...AND MOVE OFFSHORE EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 2 AM...REMNANT CONVECTION CONTINUES TO DISSIPATE ACROSS THE NC
PIEDMONT...WHILE ANOTHER AREA OF CONVECTION...FIRING ALONG AN
OUTFLOW BOUNDARY MOVING NORTH FROM THE MIDLANDS...HAS DEVELOPED
ACROSS THE LOWER SC PIEDMONT. EVEN IT IS BEGINNING TO SHOW A
DOWNWARD TREND...AS OTHER MORE WIDELY SCATTERED CELLS DEVELOP
FARTHER NW ACROSS THE UPPER SAVANNAH RIVER VALLEY. THE MAIN CHANGE
TO THE FORECAST HAS BEEN TO REARRANGE POPS BASED UPON THESE TRENDS
AND EXPECTATIONS OF OVERALL WEAKENING/DIMINISHING COVERAGE DURING
THE REMAINDER OF THE OVERNIGHT.
1000 PM UPDATE...CONVECTION CONTINUES TO FIRE OVER MAINLY THE
PIEDMONT DUE TO ENHANCED LLVL CONVERGENCE...NOT ONLY DUE TO THE
BACKDOOR COLD FRONT BUT ALSO APPARENTLY AS MOIST SOUTHERLY FLOW
INTERCEPTS THE COLD POOL. WINDS HAVE LARGELY TURNED EAST AT THE SFC
ACRS THE NE HALF OF THE FA...BUT KGSP/TCLT VWP SHOWS S TO SE WINDS
IN THE 2-5 KFT AGL LAYER. SOME CELLS ARE ALSO DEVELOPING AS EXPECTED
IN THE VICINITY OF THE NRN BLUE RIDGE. HRRR CONTINUES TO BE THE BEST
NEAR TERM MODEL AND GENERALLY SUPPORTS A SLOW DECLINE IN ACTIVITY
THRU THE NIGHT...WITH OCNL REDEVELOPMENT AS THE FRONT COMES IN. I
REVISED POPS AGAIN TO HIGHLIGHT THE DIMINISHING ACTIVITY IN OUR
EAST...BUT STILL CHC POPS EVERYWHERE WITH CONTINUED DEVELOPMENT
LIKELY ALBEIT NOT WIDE COVERAGE.
FLOOD WARNINGS/ADVISORIES REMAIN IN EFFECT ALONG THE I-77 CORRIDOR.
WHILE THE CHARLOTTE AREA PRODUCTS MIGHT BE ABLE TO EXPIRE ON
TIME...CELLS ARE NOW MOVING SWD INTO OUR NRN TIER OF ZONES WHICH
WILL PROLONG THE THREAT IN THE NRN GROUP.
AS OF 300 PM...OVER THE NEXT 24 HOURS...THE MAIN CONCERN WILL BE THE
FRONTAL ZONE DROPPING DOWN FROM THE NORTH. A SURFACE REFLECTION
ALREADY SHOWS IN THE CAPE ANALYSIS NUDGING INTO THE NW
PIEDMONT...WITH LOW CLOUDINESS AND STABLE AIR IN N CENTRAL NC. A
SHORT WAVE DROPPING DOWN INTO THE UPPER TROF OFF THE EAST COAST WILL
CONTINUE TO DRIVE THIS BOUNDARY FARTHER SOUTH AND EAST THIS EVENING.
THE MODELS DO NOT REALLY SHOW MUCH IN THE WAY OF LOW LEVEL FORCING
BUT THIS COULD BE MASKED BY THE DIURNAL CONVERGENCE TOWARD THE MTNS.
IT STANDS TO REASON THAT THE BOUNDARY MAY PROVIDE THE FOCUS FOR
CONVECTION WELL INTO THE NIGHTTIME HOURS. THERE IS SOME CONCERN FOR
FLASH FLOOD POTENTIAL OVER THE NC BLUE RIDGE AND FOOTHILLS IF THE
BOUNDARY MOVES FAR ENOUGH SOUTH TO DEVELOP A LOW LEVEL EASTERLY FLOW
THAT COULD ANCHOR STORMS NEAR THE BLUE RIDGE...BUT NOT ENOUGH
CONCERN TO ENTERTAIN A WATCH. EXPECT A DIURNAL REDUCTION IN STORM
COVERAGE AFTER MIDNIGHT IN SPITE OF THE BOUNDARY...SO SOME OF THE
LATEST SREF WAS BLENDED INTO THE POP. ON FRIDAY...SHOWERS AND STORMS
SHOULD DEVELOP YET AGAIN ACROSS THE ENTIRE FCST AREA...BUT WE MIGHT
BE COVERED WITH A LOW CLOUD CEILING BANKED UP AGAINST THE BLUE RIDGE
THAT WILL CUT DOWN ON THE POTENTIAL FOR SEVERE STORMS. TEMPS SHOULD
BE A BIT COOLER WITH THE ADDITIONAL CLOUD COVER AND EASTERLY FLOW
DEVELOPING.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
AT 215 PM EDT THURSDAY...ON FRIDAY NIGHT AN UPPER RIDGE OVER THE
NORTHERN PLAINS WILL MOVE SOUTHEAST BETWEEN A CLOSED LOW OVER LA AND
AND UPPER TROUGH OFF THE EAST COAST...REACHING THE SOUTHERN
APPALACHIANS. THE RIDGE CENTER WILL MOVE OVER THE OH RIVER VALLEY ON
SATURDAY...AND OVER GA ON SUNDAY.
A BACK DOOR COLD FRONT WILL DRIFT VERY SLOWLY SOUTH ACROSS SC ON
FRIDAY NIGHT...AND ACROSS THE SAVANNAH RIVER VALLEY ON SATURDAY.
MODEL SOUNDINGS SHOW ELEVATED INSTABILITY VERY SLOWLY DECREASING
ALONG THE BOUNDARY ON FRIDAY NIGHT...AND INCREASING AGAIN ON
SATURDAY...MAINTAINING A THREAT OF CONVECTION AND HEAVY RAINFALL. ON
SATURDAY NIGHT THE FRONT MOVES SOUTHWEST OF OUR AREA...BUT LINGERING
LOW LEVEL MOISTURE AND AN EASTERLY UPSLOPE COMPONENT WILL SUPPORT A
CHANCE PRECIPITATION ALONG THE SOUTHERN BLUE RIDGE ESCARPMENT. DRIER
AIR WORKING INTO THE AREA FROM THE NW ON SUNDAY WILL REDUCE THE
CHANCE OF PRECIPITATION...BUT THE MODEL SUGGEST THAT MOISTURE BANKED
UP AGAINST THE SOUTHERN BLUE RIDGE WILL PERSIST...AND SMALL POPS
WILL BE CARRIED THERE AGAIN.
TEMPERATURES WILL RUN ABOVE NORMAL WITH RISING HEIGHTS ALOFT...UNTIL
COOLER AIR BEHIND THE FRONT WORKS INTO THE AREA ON SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AT 215 PM EDT THURSDAY...ON MONDAY AN UPPER RIDGE WILL EXTEND FROM
FL TO THE EASTERN GREAT LAKES...WHILE A CLOSED UPPER LOW WILL BE
OVER THE WESTERN ATLANTIC AND AN UPPER TROUGH WILL BE OVER THE WEST
COAST. THE UPPER RIDGE PROGRESS TO THE EAST COAST BY TUESDAY...WHILE
A SHORTWAVE MOVES ACROSS THE GREAT LAKES AREA. THE PATTERN
DEAMPLIFIES BY WEDNESDAY...LEADING TO A LARGELY ZONAL FLOW ACROSS
THE NATION...AND WEAK FLAT RIDGING OVER THE SOUTHEAST...A PATTERN
THAT PERSISTS INTO THURSDAY.
SURFACE HIGH PRESSURE WILL BE CENTERED NEAR THE COASTAL VA AND NC ON
MONDAY...AND ALTHOUGH GULF INFLOW ON THE WEST SIDE OF THIS RIDGE
WILL BE FOCUSED OVER THE MS...TN AND OH VALLEYS...THE MODELS
INDICATE MOISTURE OVER THE SOUTHERN APPALACHIANS...WITH UPSLOPE FLOW
AND INCREASING INSTABILITY SUPPORTING DIURNALLY DRIVEN CONVECTION.
AS THE SURFACE HIGH DRIFTS SE AND OFFSHORE FROM TUESDAY THROUGH
THURSDAY...GULF INFLOW WEAKENS...BUT SPREADS EAST...COVERING NE GA
AND THE WESTERN CAROLINAS. UPSLOPE FLOW INTO ELEVATED TERRAIN WILL
BE RATHER WEAK...BUT ENOUGH TO SUPPORT THE BEST CHANCES OF
CONVECTION REMAINING ALONG THE BLUE RIDGE...EVEN AS CONVECTIVE
CHANCES INCREASE TO THE EAST.
TEMPERATURES WILL RISE FROM NEAR NORMAL VALUES...TO ABOVE NORMAL...
EVEN AS HEIGHTS FALL ALOFT...AS COOL NE FLOW VEERS TO THE SW...
AND WARM ADVECTION ENSUES.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AT KCLT AND ELSEWHERE...SHOWERS WILL REMAIN NEAR THE KCLT/KAND/KHKY
TERMINAL FOR THE NEXT COUPLE HOURS...WITH POSSIBLE OCCASIONAL MVFR
VISBY RESTRICTIONS. OTHERWISE...A VERY UNCERTAIN/LOW CONFIDENCE
FORECAST OVER THE NEXT 6 TO 8 HOURS...PRIMARILY CONCERNING CIGS...AS
GUIDANCE AND WEAK FLOW REGIME WITHIN MOIST LOW LEVEL AIR MASS
INDICATES LOW CLOUD FORMATION (IF ANY) WILL BE A RESULT OF VERY
SUBTLE PROCESSES. THIS IS FURTHER COMPLICATED BY THE PRESENCE OF
RATHER THICK MID/HIGH CLOUDS...WHICH WOULD NORMALLY PLAY A MAJOR
ROLE IN HINDERING DEVELOPMENT OF LOW CLOUDS AND FOG. HOWEVER...WE
ARE ALREADY SEEING POCKETS OF LOW CIGS DEVELOP WITH LITTLE IN THE
WAY OF ANY DISCERNIBLE PATTERN TO WHERE/WHY THEY ARE DEVELOPING.
OUR BEST COURSE OF ACTION IS TO MAKE HEAVY USE OF TEMPOS FOR IFR OR
LOW MVFR CIGS FOR AT LEAST THE NEXT FOUR HOURS. DO THINK THE
CONSIDERABLE CLOUD COVER WILL KEEP FOG AT BAY...BUT HAVE INCLUDED
MVFR VISBY AT MOST TERMINALS...AND AN OCCL IFR VISBY WILL BE
POSSIBLE...ESP IN MTN VALLEYS AND WHERE HEAVY RAINFALL OCCURRED
YESTERDAY.
SCATTERED TO NUMEROUS CONVECTIVE CELLS WILL DEVELOP AGAIN FRI
AFTERNOON...WITH VCTS/VCSH WARRANTED AT ALL TERMINALS BY EARLY
AFTERNOON...WITH CATEGORICAL -SHRA BY MID-AFTERNOON. WINDS WILL
GENERALLY REMAIN LIGHT E/NE THROUGH THE PERIOD.
OUTLOOK...ALTHOUGH GRADUAL DRYING WILL DEVELOP FROM THE NE OVER THE
WEEKEND INTO EARLY NEXT WEEK...CONTINUED BOUNDARY LAYER MOISTURE
WILL PRODUCE ISOLATED TO SCATTERED DIURNAL CONVECTION EACH
DAY...WITH MORNING RESTRICTIONS POSSIBLE.
CONFIDENCE TABLE...
06-12Z 12-18Z 18-24Z 00-06Z
KCLT HIGH 81% HIGH 81% HIGH 100% HIGH 100%
KGSP HIGH 87% HIGH 96% HIGH 100% HIGH 100%
KAVL MED 74% HIGH 99% HIGH 100% HIGH 94%
KHKY MED 68% HIGH 84% HIGH 100% HIGH 97%
KGMU HIGH 100% HIGH 97% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 97% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JAT
NEAR TERM...JDL/PM/WIMBERLEY
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...JDL
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
241 AM EDT FRI MAY 30 2014
.SYNOPSIS...
BACKDOOR COLD FRONT WILL STALL IN THE CAROLINAS TONIGHT. HIGH
PRESSURE WILL BUILD IN OVER THE EASTERN UNITED STATES BY THE
WEEKEND WITH SLIGHTLY COOLER AND DRIER AIR FOR SATURDAY AND
SUNDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1115 PM EDT THURSDAY...
LATEST RADAR TRENDS AND NEAR TERM GUIDANCE...SUCH AS HRRR AND
RAP...SHOWING CLEARER SIGNS THAT THERE WILL BE LITTLE IF ANY
ADDITIONAL DEVELOPMENT OF SHOWERS OR STORMS ACROSS THE
AREA...ONCE THE ACTIVITY ACROSS FOOTHILLS AND BLUE RIDGE OF NW NC
TAPERS OFF...WHICH IT IS SLOWLY DOING. STILL ABOUT 500 J/KG SBCAPE
DOWN IN THAT AREA...BUT THINK BY MIDNIGHT TO 1 AM THIS SHOULD BE
FADING QUICKLY. SO HAVE DECIDED TO LOWER POPS CONSIDERABLY
ELSEWHERE TO SLIGHT CHC...WAS HESITANT TO DROP ALL MENTION...AND
KEEP LIKELY POPS QUICKLY TAPERING TO CHC ACROSS THE FAR SW CORNER
OF THE FCST AREA. NO OTHER CHANGES FOR REST OF OVERNIGHT.
PREV DISCUSSION AS OF 950 PM EDT THURSDAY...
MOST SHOWERS AND STORMS HAVE DIMINISHED SIGNIFICANTLY...WITH THE
EXCEPTION OF THE FOOTHILLS OF NW NC NEAR LOCATION OF BACKDOOR
COLD FRONT WHERE SOME WEAK SFC INSTABILITY STILL EXISTS. THESE ARE
SLOW MOVING AND VERY HEAVY RAIN PRODUCERS...BUT THREAT FOR ANY
SEVERE WEATHER IS OVER. THIS FAR SW CORNER OF THE CWA FROM SMYTH
COUNTY TO WILKES AND YADKIN IS ABOUT THE ONLY PLACE WHERE
THUNDERSTORMS ARE LIKELY THE REMAINDER OF THE EVENING...BUT LEFT A
SLIGHT CHC FOR THUNDER ELSEWHERE FOR A COUPLE MORE HOURS.
OTHERWISE JUST CHC SHOWERS AND EVEN REDUCED SOME AREAS TO SLIGHT
CHC AFTER MIDNIGHT. STILL SOME SIGNIFICANT DISCREPANCIES IN HIGH
RES SHORT TERM GUIDANCE REGARDING HOW MUCH SHOWER ACTIVITY MAY
LINGER WELL PAST MIDNIGHT...AND WHILE LEANING TOWARD THOSE
SOLUTIONS WITH MOST LIMITED COVERAGE...LOWER LEVELS STILL VERY
SATURATED AND WHILE UPSLOPE FLOW FROM NORTHEAST IS VERY SHALLOW
AND WEAK...COULD BE SOME AREAS OF DRIZZLE AND FEW MORE SHOWERS
THAN SOME OF THESE MODELS SUGGEST...SO DIDN`T WANT TO DROP PRECIP
CHANCES DOWN TO SLIGHT CHC EVERYWHERE. THIS STILL MAY NEED TO BE
ADJUSTED FURTHER THOUGH. AGAIN...BEST CHANCES FOR ONGOING
SHOWER/TSTORM ACTIVITY WILL BE ACROSS FAR SW PART OF AREA REST OF
THE NIGHT.
OTHER MAIN CHANGE WAS TO INTRODUCE PATCHY FOG EARLIER PER SOME
RECENT OBSERVATIONS AND JUST PUT THIS EVERYWHERE SINCE ITS HARD TO
PINPOINT ALL THE LOCATIONS THAT WILL SEE THIS...MOST LIKELY HIGHERRIDGES
AND LOCATIONS THAT HAVE GOTTEN RECENT RAIN. ALSO WIDENED AREAS OF
FOG AFTER MIDNIGHT FOR NOT JUST PIEDMONT BUT ALSO WEST OVER BLUE
RIDGE AND INTO PARTS OF NRV AND ROANOKE VALLEY.
TEMPS WILL NOT DROP ALL THAT QUICKLY THROUGH REST OF
OVERNIGHT...BUT GOING MIN TEMPS STILL LOOK OK...ALTHOUGH DROPPED
BLF AREA A LITTLE BIT MORE SINCE THEY ARE ALREADY CLOSE TO PREV
FCST MIN.
PREV DISCUSSION AS OF 705 PM EDT THURSDAY...
BACKDOOR FRONT APPEARS TO BE MOST OF THE WAY THROUGH FCST AREA
EXCEPT PERHAPS FOR FAR SW VA AND NW NC. TEMPS...AIDED BY SHOWERS
AND THUNDERSTORMS AHVE COOLED INTO THE 60S MOST LOCATIONS...WITH A
FEW 70S NW NC FOOTHILLS. LOWER STRATUS STILL IN PIEDMONT OF VA.
MAIN FCST CHANGES WERE TO ADJUST FOR CURRENT COOLER TEMPS AND
ACCOUNT FOR HIGHER POPS MOVING FARTHER INTO MORE STABLE AIR OF VA
PIEDMONT PER LATEST RADAR...BUT LIMIT THUNDER EAST OF LYH.
STRONGER STORMS IN ALLEGHENY HIGHLANDS EARLIER SHOULD CONTINUE TO
WEAKEN AND BELIEVE THAT MAIN CONCERN FOR REMAINDER OF EVENING IS
LOCALLY HEAVY RAINFALL AND MINOR FLOODING...ESPECIALLY MORE URBAN
AREAS...RATHER THAN MUCH CHANCE FOR ANY WIND DAMAGE OR HAIL.
SBCAPE OF OVER 1000 J/KG CONFINED NOW TO NW NC. STILL...WHERE SOME
INSTABILITY PERSISTS INTO LATE EVENING...COULD CONTINUE TO SEE
SHOWERS WITH SOME EMBEDDED THUNDER CONTINUE SLOWLY DRIFTING TO THE
SOUTHEAST.
PREV DISCUSSION AS OF 407 PM EDT THURSDAY...
500 MB TROF AMPLIFIES ALONG THE EAST COAST TONIGHT INTO FRIDAY.
SHORTWAVE AND ASSOCIATED JET STREAK DROPS SOUTHEAST FROM THE OHIO
VALLEY INTO NORTH CAROLINA BY MIDNIGHT. HIGH PRESSURE OVER NEW
ENGLAND RIDGING DOWN INTO THE MID ATLANTIC REGION. BACKDOOR COLD
FRONT...HIGHLIGHTED NICELY BY MSAS ANALYSIS OF LIFTED INDEX AND
PRESSURE CHANGES...PUSHING SOUTHWARD INTO THE FORECAST AREA
THIS AFTERNOON.
THE COMBINATION OF LOW LEVEL CONVERGENCE ALONG THE SURFACE FRONT AND
THE LIFT FROM THE PASSING SHORTWAVE WILL RESULT IN SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS THIS AFTERNOON INTO TONIGHT. THE
BEST CHANCE FOR CONVECTION WILL OCCUR ALONG AND SOUTH OF THE
BACKDOOR COLD FRONT WITH BEST DESTABILIZATION. MEANWHILE...AN AREA
OF SHOWERS AND THUNDERSTORMS ACROSS SOUTHERN OHIO AND WEST VIRGINIA
WILL TRAVEL SOUTHEAST INTO OUR REGION TONIGHT. THIS AREA OF
CONVECTION WILL PROBABLY STRATIFY AS IT ENTER THE MOUNTAINS. RICH
BOUNDARY LAYER MOISTURE COMBINED WITH HEALTHILY LOW AND MID-LEVEL
LAPSE RATES AND STRONG INSOLATION SOUTH TO SOUTHWEST OF THE
BACKDOOR COLD FRONT RESULTING IN MODERATE DESTABILIZATION WITH
MLCAPE VALUES AROUND 1000 J/KG THIS AFTERNOON...SUGGESTING THAT A
FEW ROBUST UPDRAFTS MAY BE POSSIBLE. A STRONGER THUNDERSTORM THIS
AFTERNOON INTO TONIGHT COULD CONTAIN GUSTY WINDS...HAIL AND HEAVY
DOWNPOURS. SWODY1 HAD A SEE TEXT FOR STRONGER STORMS ACROSS
SOUTHERN NORTH CAROLINA AND SOUTH CAROLINA. THE MAIN CONCERN IS
FOR LOCALLY DMGG WIND...ALTHOUGH THE RISK SEEMS
DIMINISHED...BECAUSE OF LOWER DCAPE...RELATIVE TO YESTERDAY.
IN THE WAKE OF THE SHORTWAVE AND BEHIND THE COLD FRONT...EXPECT
CLOUDS AND AREAS OF LIGHT RAIN...DRIZZLE AND FOG. THE FRONTAL
BOUNDARY MAY PROVIDE THE FOCUS FOR CONVECTION TO CONTINUE INTO THE
OVERNIGHT. WITH SLOW MOVING THUNDERSTORMS WITH HEAVY RAIN AND
TRAINING OF STORMS...THERE IS THE POTENTIAL FOR FLOODING PROBLEMS
ESPECIALLY ENHANCED BY THE EASTERLY WINDS ALONG THE EASTERN SLOPES
OF THE BLUE RIDGE MOUNTAINS. PLAYED LOW TEMPERATURES CLOSE TO THE
ADJMETBC WITH READINGS FROM THE MID 50S IN THE NORTHWEST MOUNTAINS
TO THE LOWER 60S IN THE PIEDMONT.
THE CLASHING OF AIRMASSES AND SURFACE CONVERGENCE KEEPS SHOWERS AND
THUNDERSTORMS IN THE FORECAST ACROSS SOUTHERN PORTIONS OF FORECAST
AREA MAINLY IN NORTHWEST NORTH CAROLINA AND EXTREME SOUTHWEST
VIRGINIA ON FRIDAY. SWODY2 PLACED GENERAL THUNDER BASICALLY WEST OF
I77. CLOUD COVER WILL HINDER ANY SEVERE THREAT IN SOUTHERN
APPALACHIANS. HIGHS TEMPERATURES FRIDAY WILL BE BELOW
NORMAL...EXCEPT EXTREME SW VA AND SE WEST VA. HIGHS ON FRIDAY WILL
RANGE FROM THE LOWER 70S TO AROUND 80 DEGREES.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
AS OF 330 PM EDT THURSDAY...
REX BLOCK MID CONUS WILL PREVENT NORMAL WEST TO EAST PROGRESSION OF
WEATHER SYSTEMS THROUGH THE WEEKEND. CUTOFF LOW VCNTY OF THE MID MS
VALLEY IS FORECAST TO GRADUALLY WEAKEN...TAKING SEVERAL DAYS TO
BREAK DOWN BEFORE THE WESTERLIES KICK BACK IN NEXT WEEK. MEANWHILE A
DEEPENING UPPER TROUGH OVER NEW ENGLAND WILL DO MORE TO INFLUENCE
OUR WEATHER BY SUBJECTING THE FORECAST AREA TO A SEVERAL DAY PERIOD
OF EASTERLY FLOW WHICH TYPICALLY MEANS COOLER THAN NORMAL
TEMPERATURES AND POTENTIAL FOR LOW LEVEL CLOUDINESS TO GET STUCK
AGAINST THE BLUE RIDGE. MODEL SOUNDINGS HINT AT JUST THAT...WITH A
SHALLOW LAYER OF LOW LEVEL MOISTURE BANKED UP AGAINST THE EAST SIDE
OF THE BLUE RIDGE FRIDAY NIGHT THROUGH SUNDAY MORNING...IN ADDITION
TO THE POTENTIAL FOR DRIZZLE/FOG VCNTY OF THE BLUE RIDGE. WITH THIS
SORT OF PATTERN WILL FAVOR THE COOLER SIDE OF GUIDANCE...ESP EAST OF
THE APPALACHIAN DIVIDE.
BEGINNING SUNDAY...AND MORE SO FOR MONDAY...THE NEW ENGLAND TROUGH
WILL MOVE WELL OFF SHORE WITH BUILDING HEIGHTS. THIS WILL TURN THE
WIND DIAL MORE TO A SOUTHERLY DIRECTION...AND BEGIN THE WARM UP
PROCESS.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 245 PM EDT THURSDAY...
THE UPPER FLOW PATTERN NEXT WEEK FEATURES A PERSISTENT UPPER RIDGE
CENTERED OVER NORTHERN MEXICO...EXTENDING EAST ACROSS THE SOUTHERN
CONUS...INCLUDING THE SOUTHEAST STATES. NORTH OF THIS RIDGE...A
MORE ZONAL TYPE PATTERN WILL EXISTS ACROSS THE CENTRAL AND NORTHERN
CONUS...ALTHOUGH VERY NOISY...WITH EMBEDDED SHORT WAVE ENERGY
RIPPLING EAST WITHIN THE FASTER WESTERLY WINDS ALOFT.
WITH THE EXTENSION OF THE UPPER RIDGE COVERING THE SOUTHEAST STATES
WINDS SURFACE AND ALOFT WILL BE OUT OF THE WEST OR SOUTHWEST. THIS
WILL FAVOR A MORE SUMMER LIKE PATTERN WITH TEMPERATURES CLIMBING
ABOVE NORMAL...MODEL GUIDANCE SUGGESTING READINGS ABOUT 10 DEGREES
ABOVE THE NORM FOR DAYTIME HIGHS AND AT LEAST 5 DEGREES ABOVE THE
NORM FOR OVERNIGHT LOWS.
THE PATTERN ALSO SUGGESTS THE FORECAST AREA WILL BE SUBJECT TO A
DAILY THREAT OF SHOWERS AND THUNDERSTORMS...NOTHING ORGANIZED PER SE
OR LASTING FOR ANY SIGNIFICANT LENGTH OF TIME...BUT MAINLY SCATTERED
IN NATURE. IF THERE IS ANYTHING CLOSE TO BEING ORGANIZED IF WILL
MOST LIKELY COME FROM SOMETHING GENERATED OVER THE OHIO VALLEY
ASSOCIATED WITH ONE OF THE SHORTWAVE DISTURBANCES ALOFT...THIS
ACTIVITY POTENTIALLY MOVING DOWNSTREAM INTO OUR FORECAST AREA IN THE
FORM OF THUNDERSTORM CLUSTERS OR A SQUALL LINE. OUTSIDE OF THIS
UPSTREAM THREAT...LOCAL THUNDERSTORM DEVELOPMENT WILL BE THE TYPICAL
DIURNALLY DRIVEN DEEP CONVECTION...WITH BEST CHANCES IN THE
MOUNTAINS ESPECIALLY ALONG THE BLUE RIDGE WHERE WIND CONVERGENCE
WILL BE THE GREATEST. IF THE WINDS ALOFT BECOME PURE WESTERLY...A
LEE TROUGH WILL FORM OVER THE PIEDMONT WHICH COULD AID IN SCATTERED
LATE AFTERNOON STORM DEVELOPMENT THERE TOO.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
AS OF 215 AM EDT FRIDAY...
DIFFUSE BACKDOOR FRONT EVIDENT ACROSS THE WESTERN PART OF THE CWA
FROM ROUGHLY BLF-SIF. SHRA/TSRA ACTIVITY ACROSS NW NC HAS FINALLY
DISSIPATED...WITH ONLY A FEW -SHRA REMAINING IN THAT AREA. MORE
IMPORTANTLY...MOIST...EASTERLY MARITIME FLOW SETTING UP ACROSS THE
COASTAL PLAIN...SPREADING WESTWARD TOWARD THE BLUE RIDGE. THIS
WILL BE THE DOMINATE WEATHER PATTERN THIS TAF VALID PERIOD. EXPECT
EXTENSIVE LOW SC TO DEVELOP THROUGH THE MORNING HOURS AND PERSIST
THROUGH MUCH OF THE DAY...POSSIBLY BECOME BKN DURING THE MID-LATE
AFTERNOON WEST OF THE BLUE RIDGE. IN ADDITION...MOIST GROUND FROM
FAIRLY WIDESPREAD RAIN/THUNDERSTORMS THU AFTERNOON HAS ENCOURAGED
THE DEVELOPMENT OF FAIRLY WIDESPREAD FOG THIS MORNING.
THUS...ANTICIPATING MOSTLY MVFR-IFR CIGS/VSBYS THROUGH 14Z...THEN
MOSTLY MVFR CIGS AND VFR-MVFR VSBYS IN HZ THROUGH THE REMAINDER OF
THE TAF VALID PERIOD. NOT EXPECTING ANY SHRA/TSRA AT THE TAF SITES
TODAY...AS ANY THREAT OF SUCH SHOULD BE CONFINED TO NW NC.
WINDS...NE-ESE THROUGH THE TAF VALID PERIOD AT SPEEDS OF 5-7KTS.
MEDIUM CONFIDENCE IN CIGS AND VSBYS THROUGH THE TAF VALID PERIOD.
MEDIUM TO HIGH CONFIDENCE IN WIND DIR/SPD THROUGH THE TAF VALID
PERIOD.
EXTENDED AVIATION DISCUSSION...
INTO FRIDAY NIGHT...IFR CONDITIONS COULD RETURN OR CONTINUE...FOR
BLF AND LWB MAINLY...LOWER CONFIDENCE AT BCB...WITH SOME LOW LEVEL
MOISTURE TRAPPED BELOW INVERSION AND DEEPER MOISTURE IS PUSHED
FURTHER WEST AS DRY AIR ADVECTS SWWD TOWARD THE PIEDMONT. THEN
VFR CONDITIONS WILL PREVAIL FOR THE WEEKEND...EXCEPT FOR BRIEFLY
OVERNIGHT IN MOUNTAIN VALLEYS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/KK
NEAR TERM...KK/SK
SHORT TERM...PM
LONG TERM...PM
AVIATION...RAB/SK
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1004 AM EDT FRI MAY 30 2014
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS EXPECTED WITH A COLD FRONT TODAY AND
CONTINUING INTO TONIGHT. COOL WEATHER AND THE THREAT OF SHOWERS
LINGER ON SATURDAY...THEN DRY AND WARMER CONDITIONS SUNDAY INTO
MONDAY PRIOR TO A RENEWED THREAT OF WET-WEATHER BY MIDWEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE...
WILL DO THE BEST POSSIBLE TO CONVEY FORECAST ANALYSIS/THINKING
ALONG WITH CONFIDENCE CONCERNING POTENTIAL THREATS.
FIRST IMPULSE PRESENTLY SWEEPING OFFSHORE BEHIND WHICH SINKING AIR
IS PREVAILING ACTING TO ERODE MID-LEVEL CLOUDS BENEATH A DRY-AIR
INVERSION AROUND H7 AS DISCERNED PER 12Z SOUNDINGS. EXPECT A LULL
IN ACTIVITY TOWARDS MIDDAY UNDER CLEARING CONDITIONS. BOUNDARY-
LAYER DESTABILIZATION WILL PROCEED ACROSS INTERIOR NEW ENGLAND.
LOW-LEVEL LAPSE RATES TO STEEPEN. AN ENVIRONMENT TOWARDS SEA-
BREEZE DEVELOPMENT LIKELY TO GENERATE.
SECOND IMPULSE /OUR WEATHER-MAKER FOR TODAY/ PUSHING INTO N NEW
ENGLAND COLLOCATED WITH A SURFACE COLD FRONT. THIS FRONT WILL
SWEEP S ACROSS OUR REGION TOWARDS THE LATER-HALF OF TODAY INTO
THIS EVENING THROUGH AN ENVIRONMENT WHICH COULD BE CONVECTIVELY
FAVORABLE FOR WIDESPREAD SHOWERS AND THUNDERSTORMS...A FEW OF
WHICH MAY BE STRONG TO SEVERE.
CONSIDERING THE FOLLOWING: EXPECTING BROAD CYCLONIC FLOW THROUGH
WHICH 0-6 KM NW-SE STRAIGHT-LINE BULK SHEAR OF 35-40 KTS PREVAILS.
0-6 KM MEAN WIND IS ROUGHLY AROUND 20 MPH WITH CORFIDI VECTORS
AROUND 10 MPH /STRONGER THAN FORECASTED YESTERDAY/. COLDER AIR
BUILDING S WITH H5 TEMPERATURES AROUND -20C WILL ACT TO STEEPEN
MID-LEVEL LAPSE RATES TO MOIST-ADIABATIC WHILE RESULTING IN LOWER
FREEZING-LEVEL HEIGHTS DOWN TO 7 KFT.
TAKING THESE POINTS TOGETHER...INSTABILITY LOOKS MARGINAL WITH
VERY THIN CAPE PROFILES /THOUGH THRU BETTER ICE-GROWTH REGIONS/.
HIGHEST VALUES UP TO 500 J/KG. ALONG WITH SHEAR...UPDRAFTS MAY
SUSTAIN FOR A TIME. BUT WITH THE LOW-LEVEL LIFT PARENT WITH THE
MID-LEVEL IMPULSE...EXPECTING STRONG DEEP-LAYER FORCING.
SO EXPECTING A LINE OF SHOWERS AND THUNDERSTORMS ALONG AND AHEAD
OF THE COLD FRONT SWEEPING INTO THE REGION AROUND 4 PM. A FEW OF
THESE STORMS WILL CONTAIN THREATS OF SMALL HAIL AND GUSTY WINDS
/LOTS OF LOW-LEVEL DRY AIR WILL LEND TO INVERTED-V BOUNDARY-LAYER
PROFILES/. WILL PREVAIL THESE THREATS IN THE GOING FORECAST WITH
MODERATE CONFIDENCE /SPC HAS US IN A SEE-TEXT WITH THEIR DAY-1
OUTLOOK/.
WILL SEE POTENTIAL STRENGTHENING OF WEATHER ELEMENTS ALONG THE N-
AND W-SLOPES OF HIGHER TERRAIN...AND ALONG THE ANTICIPATED SEA-
BREEZE AS IT CLASHES WITH THE COLD FRONT /ENHANCEMENT OF LOW-
LEVEL CONVERGENCE AS NOTED BY THE PREVIOUS FORECASTER/.
THOUGH PWATS UP TO 1-INCH...THE STRONGER MEAN-WIND AND CORFIDI
VECTOR MOTIONS LEND TO LESSER CONFIDENCE TOWARDS FLOODING THREATS.
HEAVY RAIN IS STILL POSSIBLE.
HAVE TRENDED WITH HRRR- AND WRF-MODEL SOLUTIONS. FEEL THE MESO-NAM
IS NOT DOING TOO BAD AS WELL ALONG WITH THE RAP. THERE IS STILL A
LEVEL OF UNCERTAINTY AS TO SPECIFIC OUTCOMES THIS AFTERNOON. AM
SOMEWHAT CONCERNED OVER THE ABUNDANCE OF DRY AIR ALONG WITH THE
SINKING MOTIONS PREVAILING AT THIS TIME. WHETHER ACTIVITY MAY BE
MORE SUPPRESSED THAN THE HRRR WOULD SUGGEST IS SOMETHING WORTH
CONSIDERING AND MONITORING. STILL...FORCING SHOULD BE APPARENT
AHEAD OF THE APPROACHING COLD FRONT.
TEMPERATURES AND DEWPOINTS ON TRACK. MAY BE TOUGH TO GET ABOVE
50-DEGREE DEWPOINTS UP TO THE POINT OF RAIN. HIGHS GETTING UP INTO
THE UPPER-60S WITH SEVERAL LOCATIONS LIKELY OVER THE 70-DEGREE
MARK. COOLER ALONG THE SHORE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
TONIGHT...CYCLONIC FLOW WILL ALLOW SHOWER ACTIVITY TO CONTINUE
THROUGHOUT THE NIGHT. WITH HIGHER DEWPOINTS AND OVERCAST
SKIES...EXPECT TEMPERATURES OVERNIGHT TO BE A FEW DEGREES WARMER
THAN THE PREVIOUS TWO NIGHTS.
SATURDAY...SHOWERS ARE POSSIBLE ONCE AGAIN AS ANOTHER SHORTWAVE
MOVES ACROSS SOUTHERN NEW ENGLAND. WHILE THE COLD POOL ALOFT STICKS
AROUND...MODELS ARENT INDICATING MUCH IN THE WAY OF INSTABILITY ON
SATURDAY. THESE SHOWERS SHOULD REMAIN OVER THE INTERIOR WITH DRIER
AIR MOVING INTO THE COASTAL ZONES.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
HIGHLIGHTS...
* DRY AND WARMER SUN AND MON
* SHOWERS AT TIMES TUE INTO THU WITH NEAR NORMAL TEMPS
OVERVIEW...
MEDIUM RANGE GUIDANCE IS IN GOOD AGREEMENT ON THE OVERALL PATTERN
FOR THE EXTENDED PERIOD...BUT THERE ARE DIFFERENCES IN THE POSITION
OF A WARM FRONT TOWARD MIDWEEK WHICH WILL AFFECT TIMING OF WET
WEATHER AS WELL AS THE TEMP FORECAST. CLOSED LOW EAST OF NEW ENG
GRADUALLY HEADS FURTHER OUT TO SEA WHICH ALLOWS A PIECE OF MIDWEST
RIDGE TO BUILD INTO NEW ENG SUN AND MON WITH DRY AND WARMER
CONDITIONS. THEN THE RIDGE WILL BEGIN TO BREAK DOWN TUE AND
ESPECIALLY WED/THU AS NEXT TROF SWINGS EAST FROM THE GT LAKES WHICH
WILL BRING INCREASING THREAT OF SHOWERS AND POSSIBLE TSTMS AS A WARM
FRONT BECOMES NEARLY STATIONARY NEAR NEW ENG. THE EXACT POSITION OF
THIS FRONT WILL DETERMINE TEMPS AND POPS WED/THU.
SAT NIGHT INTO SUN...
HIGH PRES WILL BE IN CONTROL BRINGING CLEAR AND COOL CONDITIONS SAT
NIGHT WITH A WARMING TREND SUNDAY. TEMPS WILL REACH THE LOW AND MID
70S...BUT AFTERNOON SEABREEZES WILL KEEP IT COOLER NEAR THE COAST.
MONDAY...
HIGH PRES SHIFTS TO THE S OF NEW ENG WITH SW FLOW BRINGING WARMER
TEMPS WELL INTO THE 70S AND POSSIBLY SOME LOWER 80S IN THE CT
VALLEY. SUNSHINE WILL GIVE WAY TO INCREASING CLOUDS IN THE AFTERNOON
AS WARM AIR ADVECTION GETS UNDERWAY...BUT ANY SHOWERS SHOULD REMAIN
TO THE WEST. A FEW SHOWERS MAY GET INTO W ZONES OVERNIGHT MON NIGHT.
TUESDAY THROUGH THURSDAY...
INCREASING THREAT OF SCT SHOWERS AND ISOLD TSTMS AS MID LEVEL TROF
AND WARM FRONT APPROACHES FROM THE WEST BUT LOW CONFIDENCE WITH
RESPECT TO TIMING. LATEST GUIDANCE SUGGESTS A GOOD PORTION OF
SNE...ESPECIALLY EASTERN HALF MAY HOLD ON TO DRY AND WARM CONDITIONS
TUE WITH BEST CHANCE OF WET WEATHER ON WEDNESDAY. THURSDAY FORECAST
HIGHLY UNCERTAIN AND WILL HINGE ON POSITION OF THE FRONTAL BOUNDARY.
TEMP FORECAST UNCERTAIN WED/THU SO RELIED ON A BLEND OF GUIDANCE BUT
POTENTIAL FOR COOLER THAN FORECAST IF FRONT REMAINS S OF NEW ENG.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
TODAY...HIGH CONFIDENCE IN THE DEVELOPMENT OF SHRA/TSRA FROM NW
TO SE BEGINNING MIDDAY AND CONTINUING INTO THE EVENING. TEMPO
MVFR-IFR CONDITIONS MAY ACCOMPANY THESE STORMS.
TONIGHT...MODERATE CONFIDENCE. MVFR/IFR CONDITIONS POSSIBLE IN
SCT -SHRA AND FG.
SATURDAY...MODERATE TO HIGH CONFIDENCE. MAINLY VFR EXCEPT SCT
-SHRA/LOCAL MVFR ACROSS WESTERN NEW ENGLAND.
KBOS TAF...HIGH CONFIDENCE IN TAF.
KBDL TAF...HIGH CONFIDENCE IN TAF TRENDS. LOW CONFIDENCE IN EXACT
TIMING OF -SHRA/TSRA.
OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...
SAT NIGHT INTO MONDAY...HIGH CONFIDENCE. VFR. SEABREEZES SUN
AFTERNOON.
TUESDAY...MODERATE CONFIDENCE. MOSTLY VFR CIGS...BUT AREAS OF MVFR
IN SCT SHOWERS IN THE WEST.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH SATURDAY. QUIET BOATING WEATHER EXPECTED
FOR THE MOST PART. THERE IS A LOW PROBABILITY OF A FEW SHOWERS AND
THUNDERSTORMS MOVING OVER THE WATERS LATE THIS EVENING INTO TONIGHT.
WINDS AND SEAS INCREASE SLOWLY SATURDAY AFTERNOON IN RESPONSE TO AN
OCEAN STORM WELL SOUTHEAST OF THE WATERS.
OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...
SAT NIGHT INTO SUN...HIGH CONFIDENCE. MAY SEE NE WIND GUSTS
APPROACHING 25 KT OVER OUTER SE WATERS SAT NIGHT...THEN DIMINISHING
WIND SUN AS HIGH PRES BUILDS OVER THE WATERS. SEAS BUILDING TO 5 FT
OVER OUTER WATERS SAT NIGHT WITH E SWELL PERSISTING SUN.
MONDAY...HIGH CONFIDENCE. WINDS BECOMING SW LESS THAN 20 KT.
LEFTOVER E SWELL NEAR 5 FT MAY PERSIST OVER EASTERN OUTER WATERS.
TUESDAY...MODERATE CONFIDENCE. S/SE FLOW GETS UNDERWAY AHEAD OF
APPROACHING WARM FRONT. SPEEDS SHOULD REMAIN BELOW SCA.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KJC/RLG
NEAR TERM...SIPPRELL
SHORT TERM...RLG
LONG TERM...KJC
AVIATION...KJC/RLG
MARINE...KJC/RLG
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1055 AM EDT FRI MAY 30 2014
.DISCUSSION...
MORNING CAPE SOUNDING SHOWS MOIST ATMOSPHERE WITH 1.88" PRECIP
WATER. EAST COAST SEA BREEZE CIRCULATION HAS FORMED DUE TO RAPID
MORNING HEATING OF THE LAND AND LIGHT S/SE ENVIRONMENTAL FLOW.
SIMILAR TO YESTERDAY...THE SEA BREEZE HAS QUICKLY BECOME ACTIVE WITH
SHOWERS SOME OF WHICH WILL DEVELOP INTO LIGHTNING STORMS SOON. THIS
EARLY CONVECTION WILL GIVE THE SEA BREEZE AN EXTRA PUSH INTO THE
INTERIOR. SO AGREE WITH THE 3KM HRRR AND OUR LOCAL WRF MESOSCALE
MODEL THAT THE COLLISION WILL OCCUR WEST OF ORLANDO EARLY IN THE
EVE.
STRONG HEATING IN THE LOW LEVELS AND COOL TEMPS IN THE MID LEVELS
WILL PRODUCE SUFFICIENT INSTABILITY RESULTING IN SCATTERED TO
NUMEROUS COVERAGE OF STORMS OVER THE INTERIOR AND POINTS WEST.
COVERAGE WILL BE LOWER CLOSE TO THE EAST COAST. A FEW STRONG STORMS
ARE EXPECTED ESPECIALLY OVER THE INTERIOR WHERE COLLISIONS OCCUR
WITH THUNDERSTORMS OUTFLOWS AND SEA/LAKE BREEZE BOUNDARIES. STEERING
FLOW REMAINS WEAK SO STORMS WILL BE SLOW MOVING GENERALLY TOWARD THE
NORTH AND CAPABLE OF PRODUCING HEAVY RAINFALL. BUT SOME STORMS WILL
ALSO BE DRIVEN BY PROPAGATION AND TRANSLATE SOMEWHAT FASTER.
&&
.AVIATION...
SHRA/TSRA DEVELOPING ALONG THE SEA BREEZE COAST THIS MORNING WILL
PUSH INTO THE INTERIOR THIS AFTN AND INCREASE IN COVERAGE. CURRENT
TEMPO GROUPS FOR INTERIOR TERMINALS BEGINNING AT 19Z LOOKS GOOD.
&&
.MARINE...
NO SIGNIFICANT CHANGES TO CURRENT COASTAL WATERS FORECAST. FAVORABLE
BOATING CONDITIONS TODAY WITH E/SE WINDS AROUND 10 KNOTS WITH SEAS 2
FT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 88 71 88 72 / 30 10 30 10
MCO 89 71 90 71 / 50 20 50 20
MLB 86 71 88 73 / 30 10 30 10
VRB 86 70 88 72 / 30 20 30 10
LEE 90 72 90 72 / 60 20 50 20
SFB 91 72 91 72 / 50 20 40 20
ORL 90 73 90 73 / 50 20 50 20
FPR 86 70 88 72 / 30 20 40 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
KELLY/BRAGAW
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1118 AM EDT FRI MAY 30 2014
.SYNOPSIS...
A SLOW MOVING FRONTAL SYSTEM WILL BE IN THE FORECAST
AREA THROUGH TONIGHT. THE FRONT WILL BE JUST SOUTH OF THE AREA
SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE UPPER-LEVEL LOW WILL REMAIN IN THE LOWER MISSISSIPPI RIVER
VALLEY THROUGH TONIGHT. FARTHER EAST...OUR REGION WILL BE UNDER
A WEAK RIDGE. THE MODELS INDICATE A SHORTWAVE TROUGH CAUGHT IN
THIS RIDGE NEAR THE FORECAST AREA. THE LATEST ANALYSIS SHOWED H5
TEMPERATURES RELATIVELY COLD AROUND -10 C. AN EAST-WEST ORIENTED
FRONTAL SYSTEM WILL REMAIN IN THE FORECAST AREA. CONVERGENCE
ASSOCIATED WITH THE FRONT AND DIFFERENCES IN HEATING BECAUSE OF
CLOUD-COVER GRADIENTS PLUS THE COLD TEMPERATURES ALOFT SHOULD LEAD
TO THUNDERSTORMS. THE CLOUDINESS GRADIENT IN THE CSRA THIS MORNING MAY
BE FOCUS FOR THE INITIAL DEVELOPMENT OF THUNDERSTORMS THIS AFTERNOON.
LITTLE MOVEMENT WILL OCCUR BECAUSE OF THE UPPER-LEVEL RIDGE SO
EXPECT LIMITED THUNDERSTORM COVERAGE. THE HIGH-RESOLUTION MODELS
SUPPORT SCATTERED COVERAGE. THE CAE AND SPC WRF SUPPORT
THUNDERSTORMS BEGINNING AROUND 400 PM WITH THE GREATEST COVERAGE
TONIGHT MAINLY BETWEEN 700 PM AND 1000 PM. THE HRRR DISPLAYS
ISOLATED COVERAGE BEGINNING AROUND 300 PM WITH VERY LITTLE
COVERAGE THROUGH 700 PM.
THE MAIN FORECAST PROBLEM WILL BE THUNDERSTORMS WITH THE
POTENTIAL FOR HEAVY RAIN BECAUSE OF PRECIPITABLE WATER NEAR 1.8
OF AN INCH AND SLOW STORM MOVEMENT. NEAR-SEVERE WIND GUSTS MAY
OCCUR BECAUSE OF HEAVY PRECIPITATION LOADING AND THE POSSIBILITY
OF MODERATE INSTABILITY IF THERE ARE ENOUGH BREAKS IN THE
CLOUDINESS AND MORE HEATING CAN OCCUR.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
SURFACE FRONT WILL STILL BE SITUATED ACROSS THE REGION...BUT WILL
STILL BE SLOWLY PUSHING SOUTHWARD THROUGH THE DAY. PRECIPITABLE
WATER VALUES WILL BE 1.5 OF AN INCH OR GREATER THROUGH THE
CENTRAL MIDLANDS AND CSRA. FARTHER NORTH...DRIER AIR MOVING INTO
THE NORTHERN COUNTIES OF THE CWA. AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS ARE STILL EXPECTED ACROSS THE CENTRAL/SOUTHERN
MIDLANDS AND THE CSRA WHERE CONVERGENCE AHEAD OF THE FRONT WILL BE
STRONGEST. THE DRIER AIR ENTERING THE NORTHERN MIDLANDS WILL HELP
SUPPRESS CONVECTION FOR THE MOST PART ACROSS THAT AREA. THE
POTENTIAL FOR SEVERE THUNDERSTORMS WILL BE LOW...HOWEVER WITH WEAK
WINDS ALOFT PERSISTING AND RESULTING IN SLOW MOVING CELLS THE
POTENTIAL FOR LOCALIZED HEAVY RAINFALL WILL CONTINUE. TEMPERATURES
WILL BE IN THE MIDDLE 80S FOR AFTERNOON HIGHS WITH OVERNIGHT LOWS
IN THE MIDDLE 60S.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
UPPER-LEVEL RIDGING WILL BE OVER THE REGION THROUGH MONDAY WITH
THE UPPER-LEVEL PATTERN BECOMING MORE ZONAL FOR TUESDAY ONWARD.
THE FRONT WILL MOVE JUST SOUTH OF THE AREA SUNDAY AND STALL AS
HIGH PRESSURE JUST OFFSHORE OF NC TAKES CONTROL OF THE AREA. THIS
WILL KEEP DRIER AIR OVER THE FORECAST AREA FOR SUNDAY AND MONDAY
WITH MOISTURE RETURNING TO AREAS WEST OF THE FORECAST AREA TUESDAY
AS THE NEXT COLD FRONT TRACKS TOWARD THE AREA FROM THE WEST. THIS
MOISTURE WILL CONTINUE TO SPREAD INTO THE AREA INTO
WEDNESDAY...WHICH WILL HELP TO BRING CHANCES OF SHOWERS AND
THUNDERSTORMS BACK INTO THE FORECAST FOR WEDNESDAY. TEMPERATURES
THROUGH THE LONG TERM WILL BE NEAR NORMAL.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
AN EAST-WEST ORIENTED FRONTAL SYSTEM WILL REMAIN IN THE FORECAST
AREA THROUGH THE TAF PERIOD. MOISTURE ASSOCIATED WITH THE FRONT HAS
HELPED SUPPORT MAINLY MVFR CEILINGS THIS MORNING. HEATING SHOULD
HELP RAISE CEILINGS...BUT CONVERGENCE ASSOCIATED WITH THE FRONT
AND DIFFERENCES IN HEATING BECAUSE OF CLOUD-COVER GRADIENTS PLUS
COLD TEMPERATURES ALOFT SHOULD LEAD TO THUNDERSTORMS. THE CLOUDINESS
GRADIENT IN THE CSRA THIS MORNING MAY BE FOCUS FOR THE INITIAL
DEVELOPMENT OF THUNDERSTORMS THIS AFTERNOON.
SLOW STORM MOVEMENT BECAUSE OF THE UPPER-LEVEL RIDGING WILL HELP
LIMIT COVERAGE. THE HIGH-RESOLUTION MODELS SUPPORT SCATTERED
COVERAGE. THE CAE AND SPC WRF SUPPORT THUNDERSTORMS BEGINNING
AROUND 400 PM WITH THE GREATEST COVERAGE TONIGHT MAINLY BETWEEN
700 PM AND 1000 PM. THE HRRR DISPLAYS ISOLATED COVERAGE BEGINNING
AROUND 300 PM WITH VERY LITTLE COVERAGE THROUGH 700 PM.
THUNDERSTORMS MAY BEGIN EARLIER IN THE AFTERNOON AND AFFECT AGS
AND DNL BECAUSE OF THE DIFFERENTIAL HEATING OCCURRING ALONG THE
CLOUD GRADIENT THIS MORNING NEAR THE SAVANNAH RIVER.
PRECIPITABLE WATER WILL BE HIGH WITH VALUES NEAR 1.8 OF AN INCH.
VERY HEAVY DOWNPOURS MAY OCCUR WITH ANY THUNDERSTORMS. HEAVY
PRECIPITATION LOADING AND POSSIBLY MODERATE INSTABILITY IF THERE
ARE ENOUGH BREAKS IN THE CLOUDINESS MAY LEAD TO VERY STRONG WINDS
NEAR ANY THUNDERSTORMS.
EXTENDED AVIATION OUTLOOK...MOISTURE ASSOCIATED WITH THE REMNANTS
OF A STALLED FRONT WILL CONTINUE DURING MUCH OF THE OUTLOOK
PERIOD. EXPECT RESTRICTIONS AT TIMES MAINLY FROM AFTERNOON AND
EVENING THUNDERSTORMS AND EARLY MORNING STRATUS AND FOG.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
87
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1039 AM EDT FRI MAY 30 2014
.SYNOPSIS...
A SLOW MOVING FRONTAL SYSTEM WILL BE IN THE FORECAST
AREA THROUGH TONIGHT. THE FRONT WILL BE JUST SOUTH OF THE AREA
SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE UPPER-LEVEL LOW WILL REMAIN IN THE LOWER MISSISSIPPI RIVER
VALLEY THROUGH TONIGHT. FARTHER EAST...OUR REGION WILL BE UNDER
A WEAK RIDGE. THE MODELS INDICATE A SHORTWAVE TROUGH CAUGHT IN
THIS RIDGE NEAR THE FORECAST AREA. THE LATEST ANALYSIS SHOWED H5
TEMPERATURES RELATIVELY COLD AROUND -10 C. AN EAST-WEST ORIENTED
FRONTAL SYSTEM WILL REMAIN IN THE FORECAST AREA. CONVERGENCE
ASSOCIATED WITH THE FRONT AND DIFFERENCES IN HEATING BECAUSE OF
CLOUD-COVER GRADIENTS PLUS THE COLD TEMPERATURES ALOFT SHOULD LEAD
TO THUNDERSTORMS. THE CLOUDINESS GRADIENT IN THE CSRA THIS MORNING MAY
BE FOCUS FOR THE INITIAL DEVELOPMENT OF THUNDERSTORMS THIS AFTERNOON.
LITTLE MOVEMENT WILL OCCUR BECAUSE OF THE UPPER-LEVEL RIDGE SO
EXPECT LIMITED THUNDERSTORM COVERAGE. THE HIGH-RESOLUTION MODELS
SUPPORT SCATTERED COVERAGE. THE CAE AND SPC WRF SUPPORT
THUNDERSTORMS BEGINNING AROUND 400 PM WITH THE GREATEST COVERAGE
TONIGHT MAINLY BETWEEN 700 PM AND 1000 PM. THE HRRR DISPLAYS
ISOLATED COVERAGE BEGINNING AROUND 300 PM WITH VERY LITTLE
COVERAGE THROUGH 700 PM.
THE MAIN FORECAST PROBLEM WILL BE THUNDERSTORMS WITH THE
POTENTIAL FOR HEAVY RAIN BECAUSE OF PRECIPITABLE WATER NEAR 1.8
OF AN INCH AND SLOW STORM MOVEMENT. NEAR-SEVERE WIND GUSTS MAY
OCCUR BECAUSE OF HEAVY PRECIPITATION LOADING AND THE POSSIBILITY
OF MODERATE INSTABILITY IF THERE ARE ENOUGH BREAKS IN THE
CLOUDINESS AND MORE HEATING CAN OCCUR.
THE GUIDANCE WAS CONSISTENT WITH HIGHS MAINLY IN THE UPPER 80S AND
LOWS IN THE MIDDLE 60S.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
SURFACE FRONT WILL STILL BE SITUATED ACROSS THE REGION...BUT WILL
STILL BE SLOWLY PUSHING SOUTHWARD THROUGH THE DAY. PRECIPITABLE
WATER VALUES WILL BE 1.5 OF AN INCH OR GREATER THROUGH THE
CENTRAL MIDLANDS AND CSRA. FARTHER NORTH...DRIER AIR MOVING INTO
THE NORTHERN COUNTIES OF THE CWA. AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS ARE STILL EXPECTED ACROSS THE CENTRAL/SOUTHERN
MIDLANDS AND THE CSRA WHERE CONVERGENCE AHEAD OF THE FRONT WILL BE
STRONGEST. THE DRIER AIR ENTERING THE NORTHERN MIDLANDS WILL HELP
SUPPRESS CONVECTION FOR THE MOST PART ACROSS THAT AREA. THE
POTENTIAL FOR SEVERE THUNDERSTORMS WILL BE LOW...HOWEVER WITH WEAK
WINDS ALOFT PERSISTING AND RESULTING IN SLOW MOVING CELLS THE
POTENTIAL FOR LOCALIZED HEAVY RAINFALL WILL CONTINUE. TEMPERATURES
WILL BE IN THE MIDDLE 80S FOR AFTERNOON HIGHS WITH OVERNIGHT LOWS
IN THE MIDDLE 60S.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
UPPER-LEVEL RIDGING WILL BE OVER THE REGION THROUGH MONDAY WITH
THE UPPER-LEVEL PATTERN BECOMING MORE ZONAL FOR TUESDAY ONWARD.
THE FRONT WILL MOVE JUST SOUTH OF THE AREA SUNDAY AND STALL AS
HIGH PRESSURE JUST OFFSHORE OF NC TAKES CONTROL OF THE AREA. THIS
WILL KEEP DRIER AIR OVER THE FORECAST AREA FOR SUNDAY AND MONDAY
WITH MOISTURE RETURNING TO AREAS WEST OF THE FORECAST AREA TUESDAY
AS THE NEXT COLD FRONT TRACKS TOWARD THE AREA FROM THE WEST. THIS
MOISTURE WILL CONTINUE TO SPREAD INTO THE AREA INTO
WEDNESDAY...WHICH WILL HELP TO BRING CHANCES OF SHOWERS AND
THUNDERSTORMS BACK INTO THE FORECAST FOR WEDNESDAY. TEMPERATURES
THROUGH THE LONG TERM WILL BE NEAR NORMAL.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
AN EAST-WEST ORIENTED FRONTAL SYSTEM WILL REMAIN IN THE FORECAST
AREA THROUGH THE TAF PERIOD. MOISTURE ASSOCIATED WITH THE FRONT HAS
HELPED SUPPORT MAINLY MVFR CEILINGS THIS MORNING. HEATING SHOULD
HELP RAISE CEILINGS...BUT CONVERGENCE ASSOCIATED WITH THE FRONT
AND DIFFERENCES IN HEATING BECAUSE OF CLOUD-COVER GRADIENTS PLUS
COLD TEMPERATURES ALOFT SHOULD LEAD TO THUNDERSTORMS. THE CLOUDINESS
GRADIENT IN THE CSRA THIS MORNING MAY BE FOCUS FOR THE INITIAL
DEVELOPMENT OF THUNDERSTORMS THIS AFTERNOON.
SLOW STORM MOVEMENT BECAUSE OF THE UPPER-LEVEL RIDGING WILL HELP
LIMIT COVERAGE. THE HIGH-RESOLUTION MODELS SUPPORT SCATTERED
COVERAGE. THE CAE AND SPC WRF SUPPORT THUNDERSTORMS BEGINNING
AROUND 400 PM WITH THE GREATEST COVERAGE TONIGHT MAINLY BETWEEN
700 PM AND 1000 PM. THE HRRR DISPLAYS ISOLATED COVERAGE BEGINNING
AROUND 300 PM WITH VERY LITTLE COVERAGE THROUGH 700 PM.
THUNDERSTORMS MAY BEGIN EARLIER IN THE AFTERNOON AND AFFECT AGS
AND DNL BECAUSE OF THE DIFFERENTIAL HEATING OCCURRING ALONG THE
CLOUD GRADIENT THIS MORNING NEAR THE SAVANNAH RIVER.
PRECIPITABLE WATER WILL BE HIGH WITH VALUES NEAR 1.8 OF AN INCH.
VERY HEAVY DOWNPOURS MAY OCCUR WITH ANY THUNDERSTORMS. HEAVY
PRECIPITATION LOADING AND POSSIBLY MODERATE INSTABILITY IF THERE
ARE ENOUGH BREAKS IN THE CLOUDINESS MAY LEAD TO VERY STRONG WINDS
NEAR ANY THUNDERSTORMS.
EXTENDED AVIATION OUTLOOK...MOISTURE ASSOCIATED WITH THE REMNANTS
OF A STALLED FRONT WILL CONTINUE DURING MUCH OF THE OUTLOOK
PERIOD. EXPECT RESTRICTIONS AT TIMES MAINLY FROM AFTERNOON AND
EVENING THUNDERSTORMS AND EARLY MORNING STRATUS AND FOG.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
548 AM MDT FRI MAY 30 2014
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 249 AM MDT FRI MAY 30 2014
EARLY MORNING WV IMAGERY AND RAP H5 SHOW REX BLOCK PATTERN IN PLACE
OVER CENTRAL US WITH RIDGE OVER NORTHERN MISSISSIPPI RIVER VALLEY
AND CLOSED LOW OVER SOUTHERN MISSISSIPPI RIVER VALLEY. UPSTREAM
A POSITIVELY TILTED TROUGH EXTENDS FROM WESTERN CANADA AND ALONG
THE WESTERN US COAST WITH SOUTHWEST FLOW EXTENDING FROM THE EASTER
PACIFIC OCEAN ACROSS THE GREAT BASIN AND CENTRAL ROCKIES. A PLUME
OF HIGH WV IS IN PLACE ACROSS THE ROCKIES AND SOUTHERN PLAINS
ORIGINATING MAINLY FROM THE WESTERN GULF OF MEXICO.
ACTIVE PATTERN IS STILL ANTICIPATED THROUGH THIS WEEKEND AS A
SERIES OF SHORTWAVE TROUGHS EMBEDDED WITHIN THE THE SW TRANSLATE
NORTH AND EAST ACROSS THE CENTRAL ROCKIES INTO THE NORTHERN
PLAINS. TRACK WOULD GENERALLY FAVOR LOCATIONS WEST AND NORTH FOR
BETTER THUNDERSTORM COVERAGE...HOWEVER GUIDANCE CONTINUES TO SHOW
GOOD LIFT/MOISTURE/INSTABILITY IN PLACE OVER OUR CWA. HIGHER
TERRAIN IN COLORADO AND SURFACE TROUGH PROGGED TO LINGER AROUND
THE KS/CO STATE LINE WILL BE PRIMARY LOCATION FOR INITIATION FOR
THIS AFTERNOON/TONIGHT AND AGAIN ON SATURDAY. BETTER
LIFT/INSTABILITY IS PROGGED ON SUNDAY/SUNDAY NIGHT ACROSS THE
CWA...WITH SOME GUIDANCE SHOWING A SHIFT IN FLOW TO WEST-EAST AS
BLOCK FINALLY BREAKS DOWN. NOT A LOT OF CERTAINTY REGARDING THE
EXACT EVOLUTION OF THE PATTERN...HOWEVER GUIDANCE CONTINUES TO
SHOW GOOD SUPPORT FOR THUNDERSTORM ACTIVITY ACROSS THE CWA. SHEER
PROFILES GENERALLY WOULDNT SUPPORT MUCH MORE THAN SLOW MOVING
THUNDERSTORM CLUSTERS THROUGH SUNDAY...HOWEVER THERE IS ALSO THE
POTENTIAL FOR FASTER MOVING COLD POOL DOMINANT CLUSTERS (AS NAM IS
GENERALLY SHOWING) WHICH SHOULD TAKE ON MORE OF A EASTERN MOTION.
WITH MODERATE INSTABILITY IN PLACE THERE IS ALSO THE POSSIBLY FOR
A FEW ISOLATED STORMS PRODUCING MARGINALLY SEVERE HAIL...OTHERWISE
IT SEEMS WIND AND LOCALLY HEAVY RAIN WOULD BE THE MAIN CONCERN.
I FELT COMFORTABLE BUMPING UP POPS...ESPECIALLY THIS EVENING AND
SUNDAY/SUNDAY NIGHT IN THE NW WHERE MODELS ARE SHOWING BETTER
CONSISTENCY. DUE TO COMPLICATIONS OF SKY/WX CONFIDENCE IS LOWER ON
TEMPS AND WIND...SO I LEANED TOWARDS A MEAN BLEND WHICH STILL
REFLECTS ABOVE NORMAL TEMPS AND SEASONALLY BREEZY DAYTIME WINDS.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 249 AM MDT FRI MAY 30 2014
AN ACTIVE WEATHER PATTERN IS AHEAD FOR THE TRI STATE AREA IN THE
LONG TERM FORECAST...WITH CHANCES FOR SHOWERS AND THUNDERSTORMS EACH
DAY IN THE PERIOD. MODELS ARE COMING INTO BETTER AGREEMENT REGARDING
THE SHORTWAVE RIDGE DEVELOPING OVER THE HIGH PLAINS MONDAY INTO
TUESDAY WITH SOUTHWESTERLY TO WESTERLY FLOW ALOFT. THE SUBSIDENCE
ALOFT SHOULD KEEP CONDITIONS MOSTLY DRY TUESDAY...HOWEVER WITH
AFTERNOON HIGH TEMPERATURES APPROACHING CONVECTIVE TEMPERATURES OVER
THE REGION...CAP COULD BREAK IN THE WESTERN PORTIONS OF THE FORECAST
AREA IN THE AFTERNOON AND EVENING HOURS TUESDAY.
THE UPPER LEVEL RIDGE WILL BEGIN TO BREAK DOWN WEDNESDAY AS A
SHORTWAVE RIDGE TROUGH CLIPS THE NORTHERN PORTION OF THE AREA FOR
WEDNESDAY. MODELS DIFFER SOMEWHAT IN REGARD TO THE MOISTURE
AVAILABILITY AT THE MID AND UPPER LEVELS FOR WEDNESDAY. WITH UPPER
LEVEL LOW PRESSURE SYSTEM IN PLACE OVER THE WESTERN CONUS...SOME
GUIDANCE SUGGESTS MOISTURE WILL BE SOMEWHAT FUNNELED INTO THE AREA
FROM THE PACIFIC AS UPPER LEVEL PROFILES IN MODEL SOUNDINGS SHOW
AMPLE MOISTURE FOR STORM DEVELOPMENT. IN OTHER INSTANCES...THE
SOUTHWEST FLOW ALOFT WILL TAP DRY DESERT AIR AND BRING PLENTY OF DRY
AIR ALOFT...WHICH COULD POTENTIALLY BRING FIRE WEATHER CONCERNS IF
MIXING TAKES PLACE. JUST LEFT SOME POPS IN THE FORECAST WITH SOME
INSTABILITY PRESENT IN MODEL FORECASTS...BUT CONVECTION REALLY
DEPENDS ON WHETHER THE MOIST OR DRY SOLUTIONS PAN OUT FOR WEDNESDAY.
THE APPROACHING SHORTWAVE WILL PROVIDE PRIME LOCATIONS FOR LIFT OVER
THE AREA THURSDAY AT THE MID AND LOWER LEVELS SOMEWHERE OVER THE
HIGH PLAINS...WHICH WILL BRING STORM DEVELOPMENT WITH BETTER
MOISTURE AVAILABILITY AT THE LOWER AND THE MID LEVELS. BEST LOCATION AT
THE MOMENT SHOULD BE EAST OF US HIGHWAY 83...BUT MODEL AGREEMENT TO
EXACT PLACEMENT OF THE LIFT REMAINS POOR.
TEMPERATURES TO START THE PERIOD WILL BE SLIGHTLY ABOVE AVERAGE
BEFORE A SURFACE COLD FRONT MOVES THROUGH THE AREA WEDNESDAY. COOLER
AIR WILL THEN MOVE INTO THE PLAINS IN THE UPPER 70S...WHICH IS MORE
IN LINE WITH NORMAL TEMPERATURES FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 539 AM MDT FRI MAY 30 2014
VFR CONDITIONS SHOULD PREVAIL AT BOTH KGLD AND KMCK TERMINALS
THROUGH THE TAF PERIOD. SOUTH-SOUTHEAST WINDS SHOULD REMAIN BELOW
12KT AT BOTH TERMINALS THROUGH MOST OF THE TAF PERIOD...THOUGH
THERE WILL LIKELY BE A PERIOD OF GUSTY WINDS AT KGLD THIS
AFTERNOON AROUND 20KT. THUNDERSTORMS ARE EXPECTED TO DEVELOP BY
THIS AFTERNOON...HOWEVER BETTER COVERAGE WILL BE DELAYED AT BOTH
TERMINALS UNTIL THE EVENING/OVERNIGHT PERIOD. STILL NOT CONFIDENT
ENOUGH TO ADD MORE THAT VCTS UNTIL THE THUNDERSTORM ACTIVITY
ACTUALLY DEVELOPS AND WE HAVE A BETTER HANDLE ON COVERAGE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...MK
AVIATION...DR
AREA FORECAST DISCUSSION
NWS JACKSON KY
940 AM EDT FRI MAY 30 2014
.UPDATE...
ISSUED AT 940 AM EDT FRI MAY 30 2014
MINOR UPDATE THIS MORNING TO FRESHEN UP ZONE WORDING...REMOVE MENTION
OF FOG. ALSO TWEAKED GRIDS TO LATEST HOURLY OBS. OTHERWISE FORECAST
APPEARED IN PRETTY GOOD SHAPE. EXPECTING ISOLD TO SCATTERED SHOWERS
AND THUNDERSTORMS TO FIRE WITH DIURNAL HEATING AND BACKDOOR COLD
FRONTAL BOUNDARY SERVING AS A FOCUS. HRRR SUGGESTS ACTIVITY SHOULD
BEGIN TO FIRE BETWEEN 16-17Z GENERALLY SOUTHWEST OF A MOUNT STERLING
TO PAINTSVILLE LINE WITH THE BEST COVERAGE ACROSS THE SOUTHWEST.
UPDATE ISSUED AT 7 AM EDT FRI MAY 30 2014
FRESHENED UP THE GRIDS A BIT THIS MORNING USING THE LATEST OBS AND
MODEL DATA. SOME EARLY MORNING VALLEY FOG...DENSE IN PLACES...SHOULD
BE GONE BY 9 OR 930 THIS MORNING. FORECAST STILL ON TRACK WITH
SCATTERED SHOWERS AND STORMS EXPECTED TO DEVELOP BY MID MORNING AND
LAST THROUGH LATE THIS AFTERNOON BEFORE EXITING THE AREA EARLY THIS
EVENING. STILL EXPECTING A WARM AND MUGGY DAY WITH HIGHS IN THE LOW
TO MID 80S ACROSS THE BOARD. NO MAJOR CHANGES ARE ANTICIPATED WITH
THE FORECAST FOR THE REST OF TODAY...SO NO UPDATE IS PLANNED AT THIS
TIME.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 307 AM EDT FRI MAY 30 2014
THE MODELS WERE IN PRETTY GOOD AGREEMENT IN THE SHORT TERM. THE
GENERAL CONSENSUS IS FOR THE AREA TO REMAIN RAIN FREE UNTIL AROUND
SUNRISE TODAY. ONCE THE SUN IS UP ISOLATED SHOWERS AND STORMS SHOULD
BEGIN FIRING ACROSS THE SOUTHERN HALF OF THE FORECAST AREA...AS A
WEAK COLD FRONT MOVES SLOWLY SOUTHWARD ACROSS CENTRAL AND EASTERN
KENTUCKY. THE MOST ACTIVE PERIOD SHOULD BE FROM AROUND 15Z THIS
MORNING THROUGH AROUND 20Z THIS AFTERNOON. MOST OF THE PRECIPITATION
WE ARE EXPECTING TODAY SHOULD OCCUR PRIMARILY ALONG AND SOUTH OF THE
HAL ROGERS PARKWAY AND HIGHWAY 80 CORRIDOR. THE FRONT IS EXPECTED TO
EXIT THE AREA...ALONG WITH ANY PRECIPITATION ASSOCIATED WITH
IT...AROUND 1Z THIS EVENING. AFTER THAT...A STRONG RIDGE OF HIGH
PRESSURE WILL SETTLE ACROSS THE REGION...BRINGING ABOVE NORMAL
TEMPERATURES AND MOSTLY SUNNY SKIES TO THE AREA TO BEGIN THE WEEKEND.
HIGH TEMPERATURES THE NEXT COUPLE OF DAYS WILL TOP OUT IN THE LOW TO
MID 80S...WITH OVERNIGHT LOWS IN THE 60S.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 307 AM EDT FRI MAY 30 2014
THE MODELS START OUT THE EXTENDED IN PRETTY GOOD AGREEMENT ALOFT AS
THEY SHOW AN ELONGATED POCKET OF RIDGING OVER THE OHIO VALLEY WELL
WEST OF A DEEP TROUGH OFF THE NORTHEAST COAST AND NORTHWEST OF A
FILLING AND RETREATING CLOSED LOW ALONG THE WEST CENTRAL GULF COAST.
THIS SETUP SENDS THE BULK OF ANY ENERGY FROM THE PACIFIC NORTH OF
KENTUCKY THROUGH THE WEEKEND. HOWEVER...THE LOCAL RIDGING BREAKS
DOWN LATER SUNDAY NIGHT AND THE TRACK OF MINOR MID LEVEL WAVES SLIP
CLOSER TO THE STATE. OF PARTICULAR NOTE WILL BE THE WEAKNESS
INITIATED OVER THE NORTHWEST PORTION OF THE RIDGING CLOSER TO THE
CENTRAL PLAINS. THIS AREA GETS COMPLICATED DURING THE DAY MONDAY AS
THE ECMWF IS MOST AGGRESSIVE WITH A WAVE MOVING EAST FROM THE HIGH
PLAINS WHILE THE GFS AND GEM ARE WEAKER...FAVORING A WAVE MORE TO
THE NORTHWEST OVER THE NORTHERN PLAINS. THE MODELS CURL ALL THIS
ENERGY INTO A CONSENSUS TROUGH OVER THE UPPER MIDWEST AND ALONG THE
CANADIAN BORDER BY MONDAY NIGHT WHILE THE EARLIER OHIO VALLEY
RIDGING HAS SETTLED INTO THE FAR SOUTHEAST PART OF THE NATION AND
WEAKENED. ACCORDINGLY...MORE IN THE WAY OF ENERGY WILL PASS THROUGH
THE OHIO VALLEY THROUGH MIDWEEK IN CONJUNCTION WITH THE TROUGH OF
SOME SORT SLOWLY MOVING EAST ALONG THE CANADIAN BORDER THROUGH THE
NORTHERN GREAT LAKES. DURING THE DAY TUESDAY SOME SEMBLANCE OF MODEL
AGREEMENT LEAVES WITH THE ECMWF DEEPENING AND SLOWING ITS TROUGH/
CLOSED LOW AND THE GFS MOVING ITS VERSION QUICKER TO THE EAST. THE
DELAY OF THE UPPER LOW PASSING BY TO THE NORTH IN THE ECMWF WILL
ALSO SLOW THE ARRIVAL OF RENEWED RIDGING FOR KENTUCKY FROM THE
SOUTHWEST. THE GEM SEEMS TO SPLIT THE TWO OTHER MODELS AND MAY
ACTUALLY REPRESENT A GOOD COMPROMISE FOR THE END OF THE PERIOD.
EITHER WAY IT LOOKS LIKE WEDNESDAY AND THURSDAY WILL HAVE RELATIVELY
FLAT AND FAST FLOW PASSING THROUGH NORTHERN KENTUCKY AND AMPLE
ENERGY WAVES EMBEDDED WITHIN. GIVEN THE MODEL SPREAD AND CONSENSUS
FALLING IN THE MIDDLE WILL FAVOR A BLENDED SOLUTION SIMILAR TO WHAT
THE CR INIT PROVIDES.
SENSIBLE WEATHER WILL FEATURE A QUIET START TO THE EXTENDED PORTION
OF THE FORECAST WITH JUST A SMALL CHANCE FOR STORMS RETURNING FROM
THE SOUTHWEST LATE IN THE DAY SUNDAY AS HIGH PRESSURE TO THE EAST
SLIPS AWAY. FOLLOWING THIS...A DIURNAL PATTERN...OCCASIONALLY
ENHANCED FROM PASSING MIDLEVEL ENERGY PACKETS...WILL DOMINATE DURING
THIS FAIRLY TYPICAL WET PHASE OF A SUMMERY PATTERN THANKS TO AN OPEN
GULF. A COLD FRONT WILL APPROACH THE AREA AROUND MID WEEK WITH
TIMING DEFINED BY WHICH MODEL TURNS OUT TO BE MORE CORRECT ABOUT THE
PROGRESSION AND STRENGTH OF THE MID LEVEL LOW SKIRTING THE GREAT
LAKES. THE GFS WOULD BRING THIS THROUGH ON WEDNESDAY MORNING WHILE
THE ECMWF SUGGESTS THAT IT MAY NEVER CROSS INTO EAST KENTUCKY AND
INSTEAD JUST SETTLE INTO THE NORTHERN PART OF THE STATE. EITHER
WAY...A CONVECTIVELY ACTIVE PATTERN WILL CONTINUE WITH THIS BOUNDARY
NEARBY AND ENERGY ALOFT MOVING BY TO THE NORTH THROUGH THURSDAY.
STILL EXPECT THE THE DIURNAL CYCLE TO DOMINATE THE CONVECTIVE TIMING
DURING THE BULK OF THE EXTENDED WHILE WARMER THAN SEASONAL NORMAL
TEMPERATURES AND FAIRLY HIGH HUMIDITY VALUES CONTINUE.
DESPITE THE MODEL DIFFERENCES THE CR GRID LOAD CAME IN REASONABLE
FOR THE EXTENDED...THOUGH DID ADJUST THE HOURLY POP/SKY AND WX GRIDS
FOR MORE OF A DIURNALLY DRIVEN SET OF PEAKS AND VALLEYS. ALSO...FINE
TUNED THE LOW TEMPERATURE GRIDS EACH NIGHT TO IMPART GREATER RIDGE
TO VALLEY DISTINCTION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 740 AM EDT FRI MAY 30 2014
JKL...SJS...AND LOZ WILL CONTINUE TO SEE REDUCED VSBYS AND CIGS DUE
TO FOG THROUGH 13Z OR SO THIS MORNING. THE FOG IS QUICKLY DISSIPATING
AT JKL AND LOZ...SO THOSE AIRPORTS MAY BE IN THE CLEAR BY 830. SJS
HAS BEEN SOCKED IN ALL NIGHT...AS THAT SITE MAY NOT BE FREE OF FOG
UNTIL 14Z. ONCE SCATTERED SHOWERS AND STORMS ARE EXPECTED TO FIRE UP
BY AROUND 15Z AND WILL LIKELY LAST THROUGH LATE THIS AFTERNOON. DUE
TO THE SCATTERED NATURE OF THE STORMS TODAY...THE TAF SITES WILL
PROBABLY NOT BE AFFECTED DIRECTLY...BUT DID USE VCTS FOR LOZ AND SME
IN CASE A STORM STRAYS NEAR EITHER AIRPORT. ASIDE FROM THAT...VFR
CONDITIONS WILL PREVAIL THROUGH MOST OF THE TAF PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...RAY
SHORT TERM...AR
LONG TERM...GREIF
AVIATION...AR
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1101 AM CDT FRI MAY 30 2014
.DISCUSSION...
RADAR IMAGERY REVEALS THAT THE MID LEVEL LOW IS CENTERED JUST W OF
SHV THIS MORNING...WITH THE UPPER LOW STRETCHED FARTHER NE OVER
SCNTRL AR. SFC OBS AND VISIBLE SATELLITE IMAGERY ALSO DEPICT A
WEAK SFC LOW FARTHER SW OVER E TX JUST SW OF TYR...WITH AN
ATTENDANT SFC TROUGH EXTENDING NE TO ALONG THE AR/LA LINE...WHICH
HAS RESULTED IN INCREASED CONVERGENCE FOR SCT CONVECTION TO
DEVELOP TO ITS N. POCKETS OF LOCALIZED HEATING OVER WRN AND NCNTRL
LA HAS RESULTED IN AGITATED CU TOWERS...WITH WIDELY SCT CONVECTION
JUST NOW BEGINNING TO DEVELOP OVER THESE AREAS. THE 12Z NAM HAS
INITIALIZED WELL ON THE E TX SFC LOW THIS MORNING...AND WEAKENS
IT THROUGH THE AFTERNOON...WITH THE CONVECTION MORE MESOSCALE
DRIVEN ESPECIALLY OVER N LA/SW AR/SE OK/EXTREME NE TX ON THE E
SIDE OF THE MID LEVEL LOW...WHICH SHOULD PERHAPS ONLY DRIFT A TAD
FARTHER W THROUGH THE AFTERNOON. THE LATEST HRRR HAS INITIALIZED WELL ON
THE ONGOING CONVECTION THIS MORNING...WITH ADDITIONAL DEVELOPMENT
LIKELY ESPECIALLY AS ADDITIONAL HEATING IS ADDED WITHIN A VERY
MOIST ENVIRONMENT. DID MAKE SOME MINOR ADJUSTMENTS TO POPS MAINLY
FOR THIS MORNING PER CURRENT RADAR TRENDS...AND DID LOWER POPS A
TAD TO HIGH CHANCE ACROSS THE SRN SECTIONS OF NCNTRL LA WITH
CONVECTION EXPECTED TO BE MORE SCATTERED.
DID MAKE SOME MINOR ADJUSTMENTS TO MAX TEMPS THIS AFTERNOON...RAISING
THEM SLIGHTLY ACROSS THE SRN AND ERN SECTIONS OF NCNTRL LA WHERE
BREAKS IN THE CLOUD COVER HAVE ALLOWED 15Z TEMPS TO CLIMB INTO THE
UPPER 70S/NEAR 80 ALREADY. OTHERWISE...THE REMAINDER OF THE
FORECAST IS ON TRACK.
ZONE UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 83 68 83 69 87 / 60 40 60 30 40
MLU 84 68 84 67 86 / 60 40 60 30 40
DEQ 81 67 81 68 84 / 60 40 60 30 40
TXK 79 66 82 68 84 / 60 40 60 30 40
ELD 82 67 81 67 84 / 60 40 60 30 40
TYR 82 68 82 68 85 / 40 40 40 20 40
GGG 82 68 83 68 86 / 50 40 40 30 40
LFK 85 69 85 69 87 / 60 40 40 20 40
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
15
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
957 AM CDT FRI MAY 30 2014
.UPDATE...NOT MUCH CHANGE TO FORECAST. DID ADJUST AXIS OF HEAVIEST
QPF A LITTLE FURTHER WEST AS HEAVIEST PRECIP HAS DEVELOPED
IMMEDIATELY ALONG MID/UPPER LEVEL TROF OVER SE LA/SW MS. QUICK LOOK
AT THE NAM SHOWS THIS AREA CONTINUING TO GET THE STEADIEST RAINFALL
THROUGH THE DAY AS THE LOW CENTER BEGINS ITS SLOW SW DRIFT OUT OF AR.
LIKE YESTERDAY...WILL HAVE TO WATCH THE MORE ROBUST STORMS THAT
MANAGE TO DEVELOP TODAY FOR A WEAK/BRRIEF TORNADO POTENTIAL MAINLY
IN THE SOUTH. KLIX SOUNDING SHOWING NEAR 150 M2/S2 OF SR HELICITY AND
THE RAP SHOWING NEAR 20 KNOTS OF 0-1KM SHEAR THIS MORNING. LOW LCLS
WILL BE PREVALENT AS WELL AS THE NEAR TROPICAL AIRMASS (PWS ~ 1.8 IN)
REMAINS PARKED OVER THE REGION./26/
&&
.AVIATION...A MIX OF VFR/MVFR CONDITIONS PREVAIL ACROSS TAF SITES
THIS MORNING AND THIS WILL CONTINUE THROUGH THE EARLY EVENING HOURS.
SHOWERS AND THUNDERSTORMS CONTINUE TO ROTATING AROUND A PESKY UPPER
LOW CENTERED TO THE WEST OF THE AREA. THE SHOWERS AND THUNDERSTORMS
WILL BEGIN TO DIMINISH AFTER SUNSET. MVFR/IFR CONDITIONS ARE LIKELY
TO DEVELOP OVERNIGHT OVER ALL SITES. THE WINDS WILL REMAIN OUT OF
THE SOUTHEAST AT 8-12KTS BECOMING LIGHT AFTER SUNSET. /15/
&&
.PREV DISCUSSION... /ISSUED 506 AM CDT FRI MAY 30 2014/
..MORE SHOWERS AND STORMS ON TAP TODAY AND SATURDAY...
SHORT RANGE...TODAY THROUGH SATURDAY NIGHT...THE UPPER LOW WHICH
HAS BEEN PLAGUING THE REGION FOR THE PAST FEW DAYS IS EXPECTED TO
DRIFT ONLY VERY SLOWLY SOUTHWESTWARD WHILE GRADUALLY WEAKENING
THROUGH THE SHORT TERM PERIOD. EVEN THOUGH THE FEATURE IS INDEED
WEAKENING EXPECT A LOT OF RAIN AND STORMS TO REMAIN AROUND THROUGH
SATURDAY. THIS TIME YESTERDAY MORNING GULF MOISTURE TRANSPORT NORTH
INTO OUR REGION WAS BEING SOMEWHAT COMPROMISED BY OFFSHORE
CONVECTION INTERCEPTING THE BEST QUALITY JUICE. IN THE PAST 24 HOURS
THIS BLOCKAGE HAS BEEN RELIEVED A GOOD BIT...SO GULF MOISTURE INPUT
IS CURRENTLY SUBSTANTIAL DESPITE LESSENING MAGNITUDE OF ASSOCIATED
WIND VECTORS. BUT THERE IS STILL POTENTIAL FOR SOME COASTAL
CONVECTIVE MOISTURE BLOCKING TO POP UP AGAIN THROUGH THE SHORT TERM
AND THAT IS ONE REASON WHY RAIN CHANCES WILL BE A LITTLE HIGHER IN
FAR SOUTHERN ZONES THROUGH THE SHORT TERM.
FOR TODAY I HAVE INCLUDED A LIMITED RISK FOR FLOODING IN THE HWO FOR
MAINLY SOUTHERN ZONES DUE TO THE COMBINATION OF HEAVY DOWNPOURS
BEING SLIGHTLY MORE LIKELY COMPARED TO FURTHER NORTH AND BECAUSE THE
GROUND IS GENERALLY MORE SATURATED AND FLOOD-PRONE IN THOSE AREAS.
SOME STORMS YESTERDAY ACHIEVED MINOR BRIEF ORGANIZATION BUT LESSER
LOW LEVEL SHEAR TODAY SHOULD PRECLUDE THAT HAPPENING AGAIN TODAY. AN
ABUNDANCE OF CLOUDS AND PRECIP SHOULD LIMIT TEMPS AGAIN...BUT HIGHS
WILL LIKELY BE SLIGHTLY WARMER THAN WAS THE CASE YESTERDAY. FOR
TONIGHT ANTICIPATE ACTIVITY WANING A GOOD DEAL BY LATE EVENING
ALTHOUGH AT LEAST ISOLATED SHOWERS AND PERHAPS A STRAY STORM WILL
REMAIN POSSIBLE OVERNIGHT...ESPECIALLY SOUTH OF INTERSTATE TWENTY.
ON SATURDAY THE CONTINUED WEAKENING OF THE UPPER LOW WILL HELP TO
PROMOTE A MORE DIURNAL TENDENCY TO CONVECTION...MEANING A MAJORITY
OF SCATTERED TO NUMEROUS SHOWERS AND STORMS SHOULD OCCUR IN THE
AFTERNOON. HOPEFULLY THIS WILL GIVE PEOPLE WITH OUTDOOR PLANS A
WINDOW TO GET THINGS ACCOMPLISHED BUT KEEP IN MIND DURING THE
AFTERNOON THE PROBABILITY FOR AT LEAST A BRIEF SHOWER WILL BE IN
THE 50 TO 70 PERCENT RANGE. TEMPERATURES MAY MANAGE TO PEAK IN THE
MID 80S IN MANY AREAS WITH PLENTIFUL HUMIDITY MAKING CONDITIONS NOT
TERRIBLY COMFORTABLE. BY SATURDAY EVENING CONVECTION SHOULD REALLY
TEND TO DROP OFF A BIT AFTER SUNSET ALTHOUGH A STRAY SHOWER WELL
INTO THE NIGHT IS NOT IMPOSSIBLE IN FAR SOUTHERN ZONES. /BB/
LONG TERM...SUNDAY THROUGH FRIDAY. NO HUGE CHANGES TO THE LONG TERM
FORECAST. GUIDANCE TEMPS CAME IN SIMILAR TO THE PREVIOUS FORECAST.
THINGS WERE A LITTLE WARMER TOWARDS THE END OF THE WEEK WHEN SOME
DRIER AIR MOVES INTO THE REGION. OTHERWISE...LOOKS LIKE WARM AND WET
CONDITIONS WILL CONTINUE FOR THE EARLY PART OF NEXT WEEK. MODEL
SOUNDINGS SUGGEST THERE WILL BE A DECENT AMOUNT OF SURFACE BASED
INSTABILITY AVAILABLE NEARLY EACH AFTERNOON. PW VALUES REMAIN AROUND
1.5 IN OR GREATER...SO WAVES OF TROPICAL LIKE DOWNPOURS ARE LIKELY.
WITH MICROBURST SEASON HERE WOULD EXPECT SOME FAST DEVELOPING STRONG
THUNDERSTORMS TO PRODUCE SOME GUSTY WINDS ALSO...BUT NOTHING
WIDESPREAD...SO LEFT THE THE EXTENDED PORTION OF THE HWO CLEAR.
SUNDAY AND MONDAY THE BATTLING RIDGES WILL CONTINUE TO DOMINATE THE
WEATHER FOR THE ARKLAMISS. BY SUNDAY THE AREA OF LOW PRESSURE JUST
WEST OF THE CWA...WILL HAVE SLOWLY DRIFTED WEST AND SOUTH INTO THE
GULF. MOISTURE WILL CONTINUE TO BE FORCED NORTH INTO THE AREA.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS THE
AREA. IT LOOKS LIKE WAVES OF CONVECTION CAN BE EXPECTED FOR SUNDAY
AND MONDAY. AN AREA OF LOW PRESSURE/FRONTAL SYSTEM WERE EXPECTED TO
MOVE THROUGH THE MIDWEST. ANOTHER AREA OF LOW PRESSURE SEEMS TO
DEVELOP AND MEANDER OFF THE MID ATLANTIC COAST. AN AREA OF HIGH
PRESSURE CAUGHT BETWEEN THE TWO SYSTEMS FLATTENS AND ALLOWS THE
BOUNDARY TO STALL JUST NORTH AND EAST OF THE CWA. THE TAIL END OF
THE BOUNDARY MAY EXTEND INTO THE NORTHWEST ZONES LATE MONDAY INTO
TUESDAY...BECOMING THE FOCUS FOR LINGERING SHOWER AND THUNDERSTORM
ACTIVITY FOR THE EASTERN PORTIONS OF THE CWA INTO EARLY WEDNESDAY.
WHILE PLENTY OF SURFACE MOISTURE WILL BE AVAILABLE DRY PACIFIC AIR
WILL BE FLOWING FROM THE WEST. THE DOMINANT UPPER RIDGE TO THE WEST
FINALLY MOVES EAST CUTTING OFF THE LOW LEVEL MOISTURE AND BRINGING A
BREAK IN THE RAIN. SOME ISOLATED ACTIVITY WILL BE POSSIBLE...MAINLY
SOUTH ANY MAYBE EAST FROM WEDNESDAY INTO THE WEEKEND. LOOKS LIKE THE
UPPER LOW AND CORRESPONDING SURFACE FEATURE HANG OVER THE GULF INTO
THE WEEKEND...KEEPING AN AREA OF CONVECTION GOING ALL WEEK.
&&
.AVIATION...
POCKETS OF MVFR AND EVEN IFR FLIGHT CATS EXPECTED THIS
MORNING DUE MAINLY TO LOW CEILINGS. IN VFR AREAS ANTICIPATE FEW TO
SCT COVERAGE OF LOW CLOUDS MORE THAN LIKELY. SCATTERED SHOWERS AND A
FEW THUNDERSTORMS WILL BE AROUND THIS MORNING...BUT DURING THE
AFTERNOON ACTIVITY SHOULD BECOME MORE CONCENTRATED WITH
THUNDERSTORMS A GREATER POSSIBILITY. CONDITIONS SHOULD GENERALLY
IMPROVE TO VFR AWAY FROM HEAVY DOWNPOURS AND THUNDERSTORMS BY THIS
AFTERNOON ALTHOUGH MORE SUB-VFR CONDITIONS ARE LIKELY AGAIN LATE
TONIGHT. /BB/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 83 68 85 66 / 73 44 56 30
MERIDIAN 82 67 86 64 / 76 39 53 30
VICKSBURG 83 70 85 68 / 70 44 56 30
HATTIESBURG 83 69 86 68 / 77 47 61 30
NATCHEZ 83 69 85 68 / 77 44 67 30
GREENVILLE 82 70 85 69 / 70 44 55 30
GREENWOOD 82 69 85 68 / 70 44 58 30
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
544 AM CDT Fri May 30 2014
.SHORT TERM: (Through Late This Afternoon)
Issued at 342 AM CDT Fri May 30 2014
Isolated showers were occurring from Jerseyville southeast to Salem
IL early this morning with better coverage across southeast MO.
This activity was moving northwestward. The best coverage of
showers and storms this morning may occur across the southern
portion of the forecast area as weak shortwaves continue to rotate
around the persistent upper level low over southern AR and northern
LA. The best chance of showers and thunderstorms will be during the
afternoon hours as the atmosphere destabilizes due to daytime
heating. May see a little better coverage of convection this
afternoon along and just southwest of a weakening backdoor type cold
front moving slowly southwestward into northeast MO and southwest
IL. The latest HRRR model run has the best coverage of
showers/storms early this afternoon southwest of UIN and north of
COU and also southeast of STL. Highs today will be similar to
yesterday and slightly above normal with plenty of mid-high level
cloudiness along with diurnal cumulus clouds late this morning and
this afternoon.
GKS
.LONG TERM: (Tonight through Thursday)
Issued at 342 AM CDT Fri May 30 2014
With broad and slow moving ridge producing a sluggish weather
pattern over the central CONUS, persistence should provide a pretty
good first guess on upcoming sensible weather trends in most areas
heading into the weekend. Ridge axis does work east just a bit
during the weekend, but it still appears that weak disturbances
rotating around the upper low over the Gulf coast region will drift
up the east side of the ridge and into the mid-Mississippi Valley,
interacting with the weakly unstable airmass that is locked over the
area. This should mean a continued a threat of scattered showers and
thunderstorms, primarily during the afternoon and early evening
hours. We`ve used a fairly broad brush on PoPs on both Saturday and
Sunday afternoons/evenings, with the anticipation that any
fine-tuning of precipitation threat will have to wait until the
first period due to the very weak features that will be driving the
convection.
About the only location where we can rule out convection would be
extreme eastern sections of the FA on Saturday. Here, a bit of
drier air backdooring in from the east should stabilize the airmass
while the upper ridge exerts its greatest influence.
Temperatures should also reflect max/min trends of the past few days
and nights, with highs in the 80s and lows in the 60s.
Heading into the new work week, the upper ridge is forecast to
continue a slow eastward drift, which will allow a series of
shortwaves to push into the area as westerlies dip southward and
take on a more zonal look. While exact details are still a bit
sketchy, if this scenario does unfold there should be several good
chances of showers and thunderstorms in the Monday-Thursday time frame,
especially over the northern half of the FA.
With no major changes in the airmass during most of the medium
range temperatures should remain above average, with highs in the
80s and lows in the 60s.
Truett
&&
.AVIATION: (For the 12z TAFs through 12z Saturday Morning)
Issued at 519 AM CDT Fri May 30 2014
Fog in UIN and CPS should dissipate by 14z this morning. Mid-
high level cloudiness will continue to advect northwestward
through our area, north of the upper level low over northern LA and
southern AR. At least scattered diurnal cumulus clouds will
develop late this morning and this afternoon. It appears that the
isolated showers moving northwestward across portions of southeast
MO and southwest IL will miss the taf sites early this morning,
but scattered showers/storms are expected this afternoon due to
daytime heating and destabilization. Will continue with VCTS in
the tafs during the afternoon into the early evening hours. Light
surface wind will become ely later this morning and increase to
8-10 kts with a surface ridge extending from the Great Lakes
region southwest into eastern MO. The surface wind will weaken
again this evening with fog possible late tonight.
Specifics for KSTL: Mid-high level clouds will continue to advect
northwestward through STL with scattered diurnal cumulus clouds
late this morning and this afternoon. Scattered showers and
thunderstorms are expected, mainly this afternoon. Light ely
surface wind will increase to around 9 kts this afternoon, then
weaken to around 5 kts by late tonight.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
632 AM CDT FRI MAY 30 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CDT FRI MAY 30 2014
TODAY AND TONIGHT...A SUBTROPICAL MOISTURE PLUME FROM THE
REMNANTS OF HURRICANE AMANDA MOVES EAST INTO WRN NEB THIS AFTN.
THE HRRR IS LIGHTING UP THIS AREA WITH SCATTERED TSTMS FROM 19Z
ON. THIS MAY BE AN HOUR OR TWO TOO FAST. MEANWHILE THE RAP SHOWS
K INDICES OVER 40C AND A STORM MOTION AROUND 200 DEGREES AT 8
KTS. LOCALLY HEAVY RAINFALL WOULD APPEAR POSSIBLE ACROSS SHERIDAN
COUNTY. 3 HOUR FLOOD GUIDANCE IS AROUND 2 INCHES SUGGESTING SOME
POTENTIAL FOR LOCAL FLOODING. NO FLOOD WATCH WILL BE ISSUED WITH
THIS FORECAST BUT HEAVY RAIN WORDING IS IN PLACE IN THIS GENERAL
AREA.
THE MOISTURE PLUME ADVANCES EAST A BIT OVERNIGHT BUT MORE
IMPORTANT THE SFC FRONT SAGS SOUTH AND EAST TO NEAR KVTN-KIML AND
MOISTURE WILL POOL BEHIND THIS FRONT IN CONJUNCTION WITH THE
MOISTURE PLUME ALOFT. THUS TSTM COVERAGE SHOULD INCREASE THIS
AFTN AND REMAIN FAIRLY ROBUST OVERNIGHT ACROSS WRN NEB.
THE SEVERE WEATHER CONCERN COVERS MAINLY SHERIDAN COUNTY WHERE
BULK SHEAR INCREASES TO AROUND 30 KTS. THE RAP AND NAM SUGGESTED
THE BETTER CHANCE FOR SEVERE STORMS WOULD BE JUST EAST OF THE
BLACK HILLS AND THEN SOUTH INTO SHANNON COUNTY SD.
THE TEMPERATURE FORECAST IS LITTLE CHANGED FROM THE PREVIOUS
FORECAST. SOUTHEAST WINDS ARE EXPECTED TO LIMIT VERTICAL MIXING
AND HOLD HIGHS DOWN IN THE 80S AHEAD OF THE FRONT. THE RAP AND
HRRR SHOW A DRIER SOUTHEAST FLOW WITH DEEPER MIXING AND HIGHS
NEAR 90 AND THESE MODELS BLENDED WITH THE REST PRODUCES A FCST
FOR HIGHS IN THE UPPER 80S TODAY.
LOWS TONIGHT FALL INTO THE LOWER 60S AHEAD OF THE FRONT WITH 50S
BEHIND THE FRONT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 352 AM CDT FRI MAY 30 2014
UPPER LEVEL RIDGE OF HIGH PRESSURE SHIFTS TO THE EAST COAST BY
THE END OF THE WEEKEND AS A TROUGH PUSHES ACROSS THE NORTHERN
ROCKIES. A SECOND TROUGH MOVES ACROSS THE ROCKIES AGAIN BY
MIDWEEK. THIS WILL RESULT IN AN ACTIVE WEEKEND WITH UNSETTLED
WEATHER CONTINUING INTO MID WEEK.
SEVERAL MID LEVEL DISTURBANCES WILL SLIDE ACROSS THE AREA WITH
STORMS EXPECTED TO FIRE WITH EACH WAVE. ON SATURDAY A WAVE WILL
BE CROSSING THE AREA DURING THE DAY WITH A SECONDARY WAVE
ENTERING FROM THE WEST LATE. A BRIEF DRY SLOW WILL ALLOW FOR A
FEW BREAKS IN THE CLOUDS DURING THE DAY. THE SECONDARY WAVE WILL
ARRIVE LATE WITH A LOW LEVEL JET OF 30 TO 35 KTS TO SUSTAIN
ACTIVITY OVERNIGHT.
POSSIBLE BREAK IN ACTION SUNDAY MORNING AS THE ATMOSPHERE GETS
READY FOR THE NEXT WAVE LATER IN THE DAY. FLOW BECOMES A LITTLE
MORE ZONAL...COMPARED TO THE SW FLOW FOR SATURDAY. MOISTURE IS
GOOD WITH PWATS INCREASING TO 1.50 TO AS HIGH AS 1.75 AHEAD OF
THE WAVE. THE GOOD MOISTURE WILL COMBINE WITH THE ADDED SHEAR
FROM THE MID LEVEL FLOW BEING A LITTLE MORE WESTERLY AND TEMPS
INTO THE 80S WITH EARLY SUN. THIS SETS THE STAGE FOR STRONG TO
SEVERE THUNDERSTORMS TO DEVELOP. MODELS STRUGGLING WITH THE
PLACEMENT OF THE SURFACE BOUNDARY/LOW...WITH A GENERALLY
CONSENSUS OF THE LOW TO BE IN EASTERN COLORADO OR WESTERN
KANSAS...SW OF THE CWA. THE SEVERE WEATHER WILL NOT BE THE ONLY
CONCERN...AS STORMS SHOULD BE GOOD RAIN PRODUCERS WITH LOCALLY
HEAVY RAIN.
SUNDAY NIGHT INTO MONDAY WILL BE A BRIEF BREAK IN THE ACTION AS
THE NEXT WAVE ARRIVES MONDAY AFTERNOON INTO MONDAY NIGHT. THE
TRAIN OF WAVES CONTINUES AS THE NEXT UPPER LEVEL TROUGH PUSHES
ACROSS THE ROCKIES. WHILE POPS ARE IN EVERY PERIOD IN THE
EXTENDED...THERE SHOULD BE SOME BREAKS IN THE ACTION...AND EVEN
SOME CLEARING. ALTHOUGH THE BREAKS MAYBE SHORT LIVED AND TIMING
THEM IS DIFFICULT THIS FAR OUT. AS FOR TEMPS...MORE SEASONAL
TEMPS WITH HIGHS MID 70S TO THE LOWER 80S...WHICH IS CLOSE TO
NORMAL FOR THE FIRST WEEK OF JUNE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 631 AM CDT FRI MAY 30 2014
VFR IS EXPECTED EAST OF HIGHWAY 83 TODAY AND TONIGHT...WEST OF
HIGHWAY 83...MIXED CONDITIONS IN TSTMS AND MVFR CIGS.
A SUBTROPICAL MOISTURE PLUME FROM THE REMNANTS OF HURRICANE AMANDA
MOVES EAST INTO WRN NEB THIS AFTN AND ADVANCES INTO NCNTL NEB OVERNIGHT.
TSTM COVERAGE SHOULD INCREASE ACROSS WRN NEB THIS MORNING/AFTN AND REMAIN
FAIRLY ROBUST OVERNIGHT AS IT SPREADS EAST INTO NCNTL NEB.
A STATIONARY COLD FRONT NEAR KCDR WILL DRIFT SOUTH AND EAST TODAY
AND TONIGHT FORMING A BANK OF STRATUS FROM KOGA-KIML-KIEN BY
SATURDAY MORNING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
925 AM EDT FRI MAY 30 2014
.SYNOPSIS...
A BACKDOOR COLD FRONT LOCATED ACROSS SOUTHWEST VIRGINIA AND
NORTHWEST NORTH CAROLINA WILL CONTINUE TO PUSH SOUTHWESTWARD
TODAY...MOVING SOUTH OF THE FORECAST AREA BY SATURDAY.
COOLER...MORE STABLE MARITIME AIR BEHIND THE FRONT WILL RESULT IN
LESS SHOWER AND THUNDERSTORMS INTO THE WEEKEND AS HIGH PRESSURE
BUILDS OVER THE REGION. HIGH PRESSURE ALOFT WILL BUILD INTO THE
REGION NEXT WEEK BRINGING WARMER AND MORE HUMID CONDITIONS BACK TO
THE REGION ALONG WITH INCREASING CHANCES FOR AFTERNOON SHOWERS AND
THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 925 AM EDT FRIDAY...
BACKDOOR COLD FRONT THIS MORNING ACROSS WESTERN PORTIONS OF
FORECAST AREA. THIS BOUNDARY WILL CONTINUE TO PUSH SOUTHWEST
TODAY. EASTERLY WINDS PUSHING MOISTURE UP MOUNTAINS WITH LOW
CLOUDS AND FOG IN EASTERN PORTIONS OF REGION. SATELLITE LOOP
SHOWED MIXING HAS THIN OUT CLOUD COVER IN THE WEST...WHILE LOW
CLOUDS HOLDING IN THE EAST. DECREASED CLOUD COVER ON THE WESTERN
PORTION OF FORECAST AREA TO MATCH UP BETTER WITH SFC OBS AND
SATELLITE TRENDS. HRRR AND RNK WRFARW INDICATED SCATTERED
CONVECTION POSSIBLE MAINLY WEST OF I77 THIS AFTERNOON. THE SWODY1
HIGHLIGHTED THE CHANCE OF THUNDER ACROSS SOUTHWEST PORTION OF
FORECAST AREA. HIGH TEMPERATURES ARE TRICKY THIS AFTERNOON
DEPENDING ON CLOUD COVER AND CONVECTION. WITH CAUTION WILL HOLD
WITH CURRENT HIGHS AND WATCH TRENDS FOR THIS MORNING FOR
MODIFICATIONS.
AS OF 445 AM EDT FRIDAY...
DIFFUSE BACKDOOR COLD FRONT NEAR A BLF-SIF LINE. COOLER...MARITIME
LIGHT EASTERLY FLOW COMBINED WITH WET GROUND FROM LATE DAY
RAINFALL THU HAS RESULTED IN WIDESPREAD LOW CLOUDS/CIGS EARLY THIS
MORNING...ALONG WITH AREAS OF FOG. SO FAR...THE STRATUS HAS BEEN
MORE SIGNIFICANT THAN THE FOG. MODELS IN GENERAL AGREEMENT THAT
THE BACKDOOR FRONT WILL CONTINUE TO SAG SOUTHWESTWARD THROUGH THE
DAY...AND SHOULD BE SW OF THE FORECAST AREA BY EARLY SAT. THIS
WILL RESULT IN TWO WEATHER CHANGES ACROSS THE REGION TODAY AS
COMPARED TO THU. SHRA/TSRA WILL BE CONFINED TO FAR SW VA/NW
NC...WHERE THE AIR MASS WILL REMAIN UNSTABLE/WARM ENOUGH TO
SUPPORT AFTERNOON SHRA/TSRA...AND LOW CLOUDS WILL LIKELY REMAIN IN
PLACE...ESPECIALLY IN UPSLOPE AREAS EAST OF THE ALLEGHANYS/BLUE
RIDGE THROUGHOUT THE DAY AND INTO THE EVENING. SPOTTY -DZ MAY
OCCUR IN AREAS ALONG THE BLUE RIDGE...BUT MOSTLY IT WILL JUST BE
CLOUDS.
THE BIG CHALLENGE FOR TODAY...BROUGHT ON BY THE CLOUDS AND COOL
EASTERLY FLOW...WILL BE THE MAX TEMPERATURES.
GUIDANCE...ESPECIALLY THE GFS MOS APPEARS WAY TOO WARM. THE AIR
MASS UPSTREAM IS QUITE COOL FOR LATE MAY WITH TEMPS EARLY THIS
MORNING NEAR 50 ACROSS NORTHERN VA. FRANKLY...PERSISTENCE FOR
TEMPS IN WEDGE AREAS MIGHT BE THE BEST WAY TO GO TODAY...BUT HAVE
USED A BLEND OF THE COLDER MODELS...NAMELY MET MOS AND ECMWF
MOS...COMBINED WITH PERSISTENCE AND EXPECTATION THAT CLOUDS WILL
BE VERY SLOW/TOUGH TO ERODE TODAY EAST OF THE ALLEGHANY FRONT.
THIS WILL RESULT IN MAX T GENERALLY 5-7 DEGREES BELOW NORMAL AND
GOING 1-2 CATEGORIES COLDER THAN MOST MOS GUIDANCE. MIN T TONIGHT
LESS OF AN ISSUE AS CLOUDS AND LITTLE T/TD SPREAD WILL RESULT IN
RELATIVELY MILD MIN TEMPERATURES DESPITE THE WEDGE. THE EXCEPTION
WOULD BE IF DRIER AIR ADVECTING SWWD FROM THE MID-ATLANTIC REACHES
THE PIEDMONT...BUT CURRENT THINKING IS THAT THIS WILL NOT HAPPEN
QUICKLY ENOUGH TO RESULT IN ANY SUBSTANTIAL EFFECT TO MIN T SAT
MORNING.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM EDT FRIDAY...
WITH SURFACE HIGH PRESSURE EVENTUALLY SINKING SOUTH INTO THE
DELMARVA BY SUNDAY AFTERNOON...EXPECTING A DRY AND POSSIBLY
SLIGHTLY BELOW NORMAL WEEKEND. THIS HIGH WILL THEN DROP DOWN THE
EAST COAST AS THE UPPER TROUGH OVER NEW ENGLAND MOVES OUT TO
SEA...AND UPPER RIDGING TAKES HOLD THROUGH THE ENTIRE EASTERN US.
LOW CLOUDS AND FOG WILL DEVELOP OVERNIGHT WHILE THE WEDGE REMAINS
THIS WEEKEND...THEN BURN OFF DURING THE LATE MORNING AND
AFTERNOON. WINDS FINALLY VEER TO THE SW BY MONDAY...DELIVERING
MORE INSTABILITY AND A CHANCE FOR SHOWERS AND THUNDERSTORMS
THROUGH SE WEST VIRGINIA BY LATE DAY. H85 TEMPS MAY FALL TO 8C IN
THE VA PIEDMONT ON SUNDAY...BUT RAPID WAA ON SW WINDS MONDAY WILL
PUSH H85 TEMPS BACK TO 15C ON MONDAY.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 245 PM EDT THURSDAY...
THE UPPER FLOW PATTERN NEXT WEEK FEATURES A PERSISTENT UPPER RIDGE
CENTERED OVER NORTHERN MEXICO...EXTENDING EAST ACROSS THE SOUTHERN
CONUS...INCLUDING THE SOUTHEAST STATES. NORTH OF THIS RIDGE...A
MORE ZONAL TYPE PATTERN WILL EXISTS ACROSS THE CENTRAL AND NORTHERN
CONUS...ALTHOUGH VERY NOISY...WITH EMBEDDED SHORT WAVE ENERGY
RIPPLING EAST WITHIN THE FASTER WESTERLY WINDS ALOFT.
WITH THE EXTENSION OF THE UPPER RIDGE COVERING THE SOUTHEAST STATES
WINDS SURFACE AND ALOFT WILL BE OUT OF THE WEST OR SOUTHWEST. THIS
WILL FAVOR A MORE SUMMER LIKE PATTERN WITH TEMPERATURES CLIMBING
ABOVE NORMAL...MODEL GUIDANCE SUGGESTING READINGS ABOUT 10 DEGREES
ABOVE THE NORM FOR DAYTIME HIGHS AND AT LEAST 5 DEGREES ABOVE THE
NORM FOR OVERNIGHT LOWS.
THE PATTERN ALSO SUGGESTS THE FORECAST AREA WILL BE SUBJECT TO A
DAILY THREAT OF SHOWERS AND THUNDERSTORMS...NOTHING ORGANIZED PER SE
OR LASTING FOR ANY SIGNIFICANT LENGTH OF TIME...BUT MAINLY SCATTERED
IN NATURE. IF THERE IS ANYTHING CLOSE TO BEING ORGANIZED IF WILL
MOST LIKELY COME FROM SOMETHING GENERATED OVER THE OHIO VALLEY
ASSOCIATED WITH ONE OF THE SHORTWAVE DISTURBANCES ALOFT...THIS
ACTIVITY POTENTIALLY MOVING DOWNSTREAM INTO OUR FORECAST AREA IN THE
FORM OF THUNDERSTORM CLUSTERS OR A SQUALL LINE. OUTSIDE OF THIS
UPSTREAM THREAT...LOCAL THUNDERSTORM DEVELOPMENT WILL BE THE TYPICAL
DIURNALLY DRIVEN DEEP CONVECTION...WITH BEST CHANCES IN THE
MOUNTAINS ESPECIALLY ALONG THE BLUE RIDGE WHERE WIND CONVERGENCE
WILL BE THE GREATEST. IF THE WINDS ALOFT BECOME PURE WESTERLY...A
LEE TROUGH WILL FORM OVER THE PIEDMONT WHICH COULD AID IN SCATTERED
LATE AFTERNOON STORM DEVELOPMENT THERE TOO.
&&
.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
AS OF 740 AM EDT FRIDAY...
DIFFUSE BACKDOOR FRONT EVIDENT ACROSS THE WESTERN PART OF THE CWA
FROM ROUGHLY BLF-SIF. EARLIER SHRA ACTIVITY ACROSS NW NC
DISSIPATED AROUND 07Z. MOIST...EASTERLY MARITIME FLOW SETTING UP
ACROSS THE COASTAL PLAIN...SPREADING WESTWARD TOWARD THE BLUE
RIDGE WITH ATTENDANT WIDESPREAD IFR-LIFR CIGS IN PLACE EAST OF THE
ALLEGHANY FRONT. HEALTHY WEDGE...WHICH WILL AWAIT REINFORCEMENT
SAT-SUN AS SFC HIGH PRESSURE SPREADS TOWARD THE NE U.S. AND
NORTHERN MID-ATLANTIC REGION. THUS...EVEN FOR JUNE...FEEL LOW
CLOUDS WILL HANG TOUGH...LIFTING TO MVFR AFT 14/15Z...BUT LIKELY
REMAINING BKN-OVC THROUGHOUT THE DAY. ANY BREAKS IN THE OVC WILL
FILL BACK IN OVERNIGHT. FOG HAS BEEN MORE PATCHY...BUT AT A FEW
SPOTS IS LIFR...SUCH AS LWB. VSBYS SHOULD IMPROVE TO MVFR OR
BETTER AFT 15Z...BUT WITH NE FLOW EXPECT HZ TO PREVAIL MUCH OF THE
DAY EAST OF THE BLUE RIDGE. WINDS ...NE-ESE THROUGH THE TAF VALID
PERIOD AT SPEEDS OF 5-7KTS. SHRA/TSRA THIS AFTERNOON SHOULD
REMAIN WEST- SOUTH OF THE BACKDOOR FRONT...MAINLY WEST OF A BLF-
SIF LINE.
MEDIUM CONFIDENCE IN CIGS AND VSBYS THROUGH THE TAF VALID PERIOD.
MEDIUM TO HIGH CONFIDENCE IN WIND DIR/SPD THROUGH THE TAF VALID
PERIOD.
EXTENDED AVIATION DISCUSSION...
INTO FRIDAY NIGHT...IFR CONDITIONS COULD RETURN OR CONTINUE...FOR
BLF AND LWB MAINLY...LOWER CONFIDENCE AT BCB...WITH SOME LOW LEVEL
MOISTURE TRAPPED BELOW INVERSION AND DEEPER MOISTURE IS PUSHED
FURTHER WEST AS DRY AIR ADVECTS SWWD TOWARD THE PIEDMONT. THEN
VFR CONDITIONS WILL PREVAIL FOR THE WEEKEND...EXCEPT FOR BRIEFLY
OVERNIGHT IN MOUNTAIN VALLEYS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RAB
NEAR TERM...KK/RAB
SHORT TERM...KM
LONG TERM...PM
AVIATION...RAB/SK
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
316 PM PDT FRI MAY 30 2014
.SYNOPSIS...
A COUPLE OF LOW PRESSURE SYSTEMS WILL MOVE OVER THE REGION
THROUGH NEXT WEEK WITH NIGHT TO MORNING LOW CLOUDS AND FOG...THEN
THE AFTERNOONS WILL HAVE FAIR SKIES FOR INLAND AREAS AND SOME
CLEARING AT THE COAST. THERE WILL BE BREEZY WINDS IN THE MOUNTAINS
AND DESERTS OVER THE WEEKEND. THE TEMPERATURES WILL BE NEAR NORMAL
THROUGHOUT THE FORECAST PERIOD.
&&
.SHORT TERM (TONIGHT-MONDAY)...
SOUTHWEST FLOW ALOFT CONTINUES ACROSS THE AREA FROM A TROUGH OF
LOW PRESSURE OVER THE NORTH COAST OF CALIFORNIA...AND A RIDGE OF
HIGH PRESSURE OVER THE UPPER PLAINS STATES. AT THE
SURFACE...ONSHORE FLOW WILL REMAIN IN PLACE THROUGH THE WEEKEND
KEEPING TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS.
A WIND ADVISORY WAS ADDED FOR THE SANTA BARBARA SOUTH COAST AND
MOUNTAINS THIS EVENING AS NAM-WRF SOLUTIONS SUGGESTS SURFACE
PRESSURE GRADIENTS TIGHTENING LATER TONIGHT. GRADIENTS ACROSS
SANTA BARBARA COUNTY THIS AFTERNOON ARE TIGHTENING...WITH KSBA-
KSMX SURFACE PRESSURE GRADIENTS AT -2.2 MB THIS AFTERNOON. IF
SURFACE TRENDS CONTINUE...A KSBA-KSMX SURFACE GRADIENT AROUND 4
MB CAN BE EXPECTED BETWEEN 7 PM AND 10 PM THIS EVENING. IN
ADDITION...NAM-WRF SOLUTIONS SUGGEST 20 TO 25 KNOTS BETWEEN
GAVIOTA AND GOLETA...AND 3-KM HRRR SOLUTIONS INDICATE 20 TO 30
KNOTS AT THE SURFACE BETWEEN GOLETA AND GAVIOTA.
OTHERWISE...INCREASING SOUTHWEST FLOW ALOFT SHOULD OCCUR OVER THE
WEEKEND AS A SERIES OF TROUGHS OF LOW PRESSURE APPROACH THE AREA.
THE MARINE LAYER SHOULD DEEPEN AND INCREASE ONSHORE FLOW OVER THE
WEEKEND...WITH THE BEST COOLING OCCURRING ALONG THE CENTRAL COAST.
NO RAIN OR DRIZZLE IS EXPECTED AT THIS TIME WITH THE TROUGH...BUT
THERE IS A TIME PERIOD ON MONDAY WHERE THE MOUNTAINS MAY HAVE SOME
CLOUDINESS AS A DIFLUENT FLOW PATTERN DEVELOPS. IF THE MODELS
CHANGE COURSE SOMEWHAT AND PROVIDE SOME MOISTURE...THERE COULD BE
A THREAT OF MOUNTAIN SHOWERS ON MONDAY AFTERNOON AND EVENING.
.LONG TERM (TUESDAY-FRIDAY)...
SOUTHWEST FLOW ALOFT SHOULD PERSIST INTO NEXT WEEK KEEPING A
PERSISTENT MARINE LAYER IN PLACE AND TEMPERATURES NEAR NORMAL.
SOME DEEPENING OFF THE MARINE AND A COOLING TREND COULD DEVELOP
FOR THE LATTER HALF OF NEXT WEEK AS A TROUGH OF LOW PRESSURE
APPROACHES THE AREA.
&&
.AVIATION...30/1840Z.
MODERATE TO HIGH CONFIDENCE IN TAFS OVERALL. EXPECT SLIGHTLY MORE
WIDESPREAD MARINE LOW CLOUD COVERAGE FOR THE OVERNIGHT
PERIOD...WITH IFR CONDS FOR THE CENTRAL COAST SITES AND IFR/LOW
MVFR FOR KOXR AND THE L.A. COAST SITES. THERE IS A 20% CHANCE THAT
LOW CLOUDS WITH LIFR/LOW IFR CONDS WILL AFFECT KSBA...KBUR AND
KVNY AFTER 12Z SAT. MODERATE CONFIDENCE IN TIMING OF MARINE LAYER
ONSET AND HEIGHT OF CIGS/VSBY.
KLAX...MODERATE TO HIGH CONFIDENCE IN 18Z TAF. LOW MVFR CIGS
EXPECTED TO ARRIVE BY 09Z BUT TIMING MAY DIFFER BY UP TO 2 HRS FROM
TAF TIME. 30% CHANCE CIGS WILL DIP INTO THE IFR CATEGORY.
KBUR...HIGH CONFIDENCE IN 18Z TAF. THERE IS A 10 TO 20 PERCENT
CHANCE OF LIFR/IFR CIGS AFTER 12Z SAT.
&&
.MARINE...30/830 AM.
GOOD CONFIDENCE IN NORTHWEST WINDS AT SCA LEVEL OVER THE OUTER
WATERS THROUGH LATE TONIGHT. STRONGER WINDS HAVE SPREAD INTO THE
WATERS BETWEEN SAN NICOLAS ISLAND AND SANTA ROSA ISLAND SO AN
ADVISORY WAS ISSUED FOR PZZ676 THROUGH LATE TONIGHT...IN ADDITION TO
PZZ670/673. THERE IS A CHANCE THAT ADVISORY LEVEL WINDS WILL PERSIST
INTO SATURDAY MORNING...BUT WILL WAIT FOR 12Z MODEL RUNS AS
CONFIDENCE IS NOT HIGH AT THIS POINT. HOWEVER...MODERATE WINDS 10 TO
20 KNOTS ARE LIKELY TO PERSIST THROUGH THE WEEKEND AND INTO EARLY
NEXT WEEK ACROSS THE OUTER WATERS. FOR THE INNER WATERS...WINDS UP
TO 20 KNOTS ARE EXPECTED ACROSS THE SANTA BARBARA CHANNEL EACH
EVENING THROUGH SUNDAY...OTHERWISE MAINLY LIGHT WINDS ARE EXPECTED
FOR PZZ650/655.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...HALL
AVIATION/MARINE...SMITH
SYNOPSIS...SETO/HALL
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1109 AM MDT FRI MAY 30 2014
.UPDATE...
ISSUED AT 1049 AM MDT FRI MAY 30 2014
REINITIALIZED GRIDS WITH RECENT OBSERVATIONS. ALSO ADJUSTED POPS
TO BETTER REFLECT RADAR OBS. NO OTHER CHANGES TO FORECAST AT THIS
TIME. LW
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM MDT FRI MAY 30 2014
CURRENTLY...CONVECTION OVER THE FAR EASTERN PLAINS GRADUALLY
FADING AWAY AS OF 09Z...AND WITH LATEST HRRR SUGGESTING LITTLE
PRECIP EAST OF I-25 THROUGH MID MORNING...WILL GO WITH A DRY
FORECAST WITH THE NEW SET OF GRIDS. STILL SOME ISOLATED -SHRA OVER
THE MOUNTAINS AND HIGH VALLEYS...AND WITH PRECIP MOVING TOWARD THE
AREA FROM NRN NM/WRN CO...WILL INCLUDE SOME LOW POPS FOR SHOWERS
OVER MUCH OF THE HIGHER TERRAIN THIS MORNING.
TODAY...MID LEVEL MOISTURE PLUME FIRMLY IN PLACE OVER COLORADO
TODAY...WITH INCREASING LOW LEVEL MOISTURE OVER THE EASTERN
MOUNTAINS AND PLAINS AS WELL. WELL DEFINED SHORT WAVE TROUGH JUST
SOUTH OF THE FOUR CORNERS EARLY THIS MORNING WILL LIFT NORTHEAST
ACROSS THE STATE THROUGH THE DAY...PROVIDING FAIRLY STRONG UPWARD
MOTION. OVERALL...FACTORS LOOK FAIRLY GOOD FOR CONVECTION MOST
AREAS...AND EXPECT STORMS TO FIRE FAIRLY QUICKLY BY LATE MORNING AS
PEAK LIFT FROM THE UPPER WAVE OCCURS FROM MID-MORNING THROUGH MID-
AFTERNOON. NOT MUCH IN THE WAY OF SHEAR FOR SEVERE STORMS
TODAY...THOUGH A COUPLE LOW END PULSE SEVERE HAILERS WILL BE
POSSIBLE. MAIN THREAT WILL BE HEAVY RAIN OVER THE BURN
SCARS...ESPECIALLY BLACK FOREST/WALDO CANYON SCARS WHERE MOISTURE IS
SLIGHTLY DEEPER. CLOUDS AND PRECIP WILL HOLD TEMPS BACK TODAY...WITH
READINGS SEVERAL DEGF COOLER THAN YESTERDAY.
TONIGHT...WITH UPPER WAVE LIFTING NORTHEAST FAIRLY QUICKLY...SUSPECT
MAIN BODY OF CONVECTION WILL BE OVER THE EASTERN PLAINS IN THE LATE
EVENING...THEN MOVE INTO KS OVERNIGHT. STILL ENOUGH MOISTURE FOR A
FEW -SHRA TO LINGER OVER MAINLY THE HIGHER TERRAIN PAST
MIDNIGHT...THOUGH INTENSITY SHOULD BE FAIRLY LIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 316 AM MDT FRI MAY 30 2014
...SEVERE STORMS POSSIBLE SATURDAY...
FAIRLY ACTIVE LATE SPRING PATTERN EXPECTED THIS WEEKEND AND THROUGH
THE EXTENDED...AS A COUPLE SHORT WAVE TROUGHS MOVE THROUGH THE
CENTRAL ROCKIES.
SATURDAY...LOOKS LIKE THE BEST BET IN THE SHORT-MEDIUM RANGE FOR SVR
WX. DEEP SHEAR INCREASES AS THE FIRST SHORT WAVE MOVES FROM THE
INTER-MTN REGION INTO THE ROCKIES. SRLY SURFACE WINDS WILL MAINTAIN
DECENT MOISTURE OVER THE PLAINS THROUGH THE DAY...ALTHOUGH SOME
DRYING MAY OCCUR BY AFTERNOON OVER WRN PORTIONS OF THE CWA. BEST BET
FOR SVR WILL BE E OF A LINE FROM KLHX TO KIM IN THE LATE AFTERNOON
AND EARLY EVE. BULK SHEAR OF 40+ KTS...AND CAPE OF AROUND 1500 J/KG
WILL BE CONDUCIVE TO SUPERCELLS WITH THE POTENTIAL FOR LARGE HAIL
AND DAMAGING WINDS. GENERALLY HIGH LCLS WILL MINIMIZE THE TORNADO
THREAT. STORMS WILL INITIATE OVER THE HYR TRRN...THEN MOVE ONTO THE
PLAINS BY LATE AFTERNOON...EXITING INTO KS BY LATE EVE.
SUNDAY...LESS CERTAINTY ON THE SVR THREAT. DRY W-SW FLOW WILL BE
INCREASING AS THE TROUGH MOVES THROUGH THE NRN ROCKIES...AND A DRY
LINE WILL MIX EWD IN THE AFTERNOON. LOOKS LIKE THE GREATEST THREAT
FOR STRONG STORMS WILL REMAIN E OF THE CWA...BUT THE KS BORDER
COUNTIES COULD POTENTIALLY SEE AN EARLY STORM. SUN SHOULD BE THE
WARMEST DAY OF THE PERIOD...WITH TEMPS TOPPING OUT AS HIGH AS THE
MID 90S OVER THE I-25 CORRIDOR.
MON-WED...LOOKS RELATIVELY DRY AS UPPER FLOW CONTINUES FROM THE W-
SW. IT WILL BE PRETTY WARM OVER THE PLAINS...WITH MAX TEMPS IN THE
UPPER 80S TO NR 90 EACH DAY. COULD SEE SOME MARGINAL FIRE WX THREAT
DEVELOP...ESPECIALLY TUESDAY...AS MID LEVEL FLOW INCREASES TO 40-50
KTS. RED FLAG CONDITIONS WILL LIKELY BE DEPENDENT ON LOCAL FUEL
STATUS DURING THIS PERIOD.
BY THU-FRI...SHOULD SEE TEMPS MODERATE AS THE SECOND SHORT WAVE
TROUGH MOVES THROUGH CO. THERE IS REASONABLE AGREEMENT BETWEEN THE
GLOBAL MODELS ON THE OVERALL SYNOPTIC PATTERN. LATEST GFS SHOWS
PRETTY DEEP MOISTURE BACKING INTO THE SRN FRONT RANGE ON FRIDAY...
BRINGING A RETURN THREAT OF LOCALLY HEAVY RAIN AND POSSIBLY SOME
STRONG STORMS. HAVE BOOSTED POPS SLIGHTLY FOR THIS LATTER PERIOD
TO ACCOUNT FOR GOOD MODEL AGREEMENT AND POTENTIAL FOR HIGH QPF.
ROSE
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1049 AM MDT FRI MAY 30 2014
GENERALLY VFR AT KCOS...KPUB AND KALS TAF SITES NEXT 24 HOURS.
HOWEVER...A COMBINATION OF AN UPPER LEVEL DISTURBANCE AND BETTER
MOISTURE THAN YESTERDAY WILL RESULT IN MORE WIDESPREAD AND MORE
INTENSE CONVECTION THAN YESTERDAY. POSSIBILITY OF MVFR/IFR/LIFR
CONDITIONS ASSOCIATED WITH THIS ACTIVITY AT ANY OF THE TAF
SITES...BUT MOST LIKELY AT KCOS. PRIMARY WINDOW OF CONVECTION WILL
RUN 18Z-02Z. OTHER CONCERNS ASSOCIATED WITH STORMS WILL INCLUDE
LIGHTNING...WIND GUSTS TO AROUND 60 MPH...AND LOCAL 1/2 TO 1 INCH
DIAMETER HAIL. THE MOST INTENSE STORMS ARE LIKELY TO OCCUR ALONG
AND NEAR THE KANSAS BORDER IN THE AREA OF RICHEST LOW LEVEL
MOISTURE AND STRONGEST WIND SHEAR.
ON SATURDAY...DRIER AIR MOVES IN. HOWEVER...STILL ENOUGH MOISTURE
AROUND FOR SOME ISOLATED AFTERNOON AND EVENING THUNDERSTORMS. SUCH
ACTIVITY WILL BE MOST LIKELY ACROSS THE CENTRAL MOUNTAINS...PIKES
PEAK REGION AND KANSAS BORDER AREAS...INITIALIZING 18Z-20Z.
POTENTIAL FOR SEVERE STORMS WILL BE A LITTLE HIGHER SATURDAY AS
WIND SHEAR INCREASES. LW
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...LW
SHORT TERM...PETERSEN
LONG TERM...ROSE
AVIATION...LW
AREA FORECAST DISCUSSION
NWS TAUNTON MA
333 PM EDT FRI MAY 30 2014
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS INTO THIS EVENING LINGER THROUGH THE
OVERNIGHT ALONG AND AHEAD OF A COLD FRONT. COOL WEATHER AND THE
THREAT OF SHOWERS LINGER THROUGH SATURDAY...THEN WARMER AND DRY
CONDITIONS FOLLOW FOR SUNDAY INTO EARLY NEXT WEEK. ANOTHER CHANCE
OF WET-WEATHER IS POSSIBLE BY MIDWEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
4 PM UPDATE...
SHOWERS AND THUNDERSTORMS /A FEW OF WHICH THAT ARE NOTABLY STRONG
WITHIN THE LATEST RADAR SCANS/ BECOMING MORE WIDESPREAD INTO S
NEW ENGLAND AS THE PARENT MID-LEVEL IMPULSE AND COLD FRONT SWEEP
INTO THE REGION.
ENVIRONMENT ALONG AND AHEAD A COMBINATION OF MODEST STRAIGHT-LINE
BULK SHEAR AND MEAGER INSTABILITY ON THE ORDER OF 250-500 J/KG PER
SPC MESOANALYSIS /SKINNY CAPES PER RAP-MODEL SOUNDINGS/. AS SUCH
AND TO NO SURPRISE...OBSERVING SMALL-CORES WITH STORMS WHICH DO
SUSTAIN FOR A SHORT PERIOD OF TIME...ENOUGH TO SUPPORT THE THREAT
OF SMALL HAIL DUE TO THE LOW FREEZING LEVEL HEIGHTS AND COLD-
POOL ALOFT...AS WELL AS GUSTY WINDS WITH DRY LOW-LEVELS AND
INVERTED-V BOUNDARY-LAYER PROFILES.
THUS WILL CONTINUE TO RIDE WITH THE FORECAST OF WIDESPREAD SHOWERS
AND THUNDERSTORMS INTO THIS EVENING...TO WHICH SOME OF THE STORMS
MAY CONTAIN THE THREATS OF SMALL HAIL AND GUSTY WINDS.
STORMS MAY CONGEAL INTO A LINE LATE IN THE FORECAST PERIOD AHEAD
OF THE COLD FRONT AS THE HRRR WOULD SUGGEST. FIGURE THIS BE THE
CASE AS THE COLD FRONT CLASHES WITH THE SEA-BREEZE GENERATING A
REGION OF LOCALIZED CONVERGENCE. NEED TO ALSO MONITOR FOR
ENHANCEMENT OF THREATS ALONG THE N- AND W-FACING SLOPES OF HIGH
TERRAIN. HEAVY RAIN REMAINS A THREAT THOUGH A LOW ONE TO SMALL
HAIL AND GUSTY WINDS.
BOUNDARY-LAYER WHICH AS DESTABILIZED ALLOWING FOR STEEP LOW-
LEVEL LAPSE RATES AND INVOKING BRISK E-FLOW TO THE REAR OF AN
ONSHORE SEA-BREEZE FROM THE E /DISCERNED VIA LATEST OBS AND
VISIBLE SATELLITE/.
CONTINUE TO TREND WITH HRRR- AND WRF-MODEL SOLUTIONS ALONG WITH
THE LATEST RAP.
TONIGHT...
RAINS LINGER ALONG THE COLD FRONT AS IT SWEEPS OFFSHORE. EXPECTING
THUNDERSTORM ACTIVITY TO DIMINISH WITH CONCLUSION OF BUOYANCY WITH
PEAK-HEATING. N-WINDS PREVAILING BEHIND WHICH COOLER AND DRIER AIR
BUILDS SOUTHWARD. YET ANOTHER MID-LEVEL IMPULSE ROUNDING THE BROAD
CYCLONIC FLOW APPROACHES FROM THE NE AND INVOKES LOW- TO MID-LEVEL
ASCENT OF RESIDUAL MOISTURE. RENEWANCE OF WIDELY SCATTERED LIGHT
SHOWERS IS ANTICIPATED ACROSS E NEW ENGLAND OVERNIGHT...SHIFTING W
TOWARDS INTERIOR NEW ENGLAND INTO SATURDAY MORNING.
MOSTLY CLOUDY CONDITIONS BENEATH WHICH BRISK N-WINDS PREVAIL. WILL
BE A COOL AND DAMP NIGHT. EXPECTING LOWS TO DIP INTO THE 40S. MAY
HAVE TO CLOSELY MONITOR FOR PATCHY DENSE FOG EARLIER RAINS WILL
LIKELY RESULT IN HIGHER DEWPOINT AIR.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
SATURDAY...
MID-LEVEL IMPULSE PUSHES W INTO THE HUDSON RIVER VALLEY ALONG WITH
LIGHT SHOWER ACTIVITY. SINKING DRIER AIR BUILDS REARWARD ACTING TO
SUPPRESS ACTIVING E TO W.
DO NOT BELIEVE THE ENVIRONMENT AHEAD WILL BE ALLOWED TO DESTABILIZE.
FEEL THE WAVE WILL BE W OF THE REGION BY MIDDAY WITH THE LATER-HALF
OF THE DAY DRY /EXCEPT PERHAPS ALONG THE E-SLOPES OF HIGHER TERRAIN
WITH OROGRAPHIC CONVERGENCE/. THUS NO THUNDERSTORMS ARE EXPECTED.
ONSHORE FLOW BENEATH H85 TEMPERATURES AROUND +4C...GOING TO BE A
CHILLY DAY. WITH THE LATE-MAY SUN BREAKING OUT DURING THE LATER-HALF
OF THE DAY...WILL PREVAIL WITH HIGHS IN THE MID- TO UPPER-60S.
SATURDAY NIGHT...
SUBSIDENCE PREVAILS. HIGH PRESSURE IN CONTROL. LIGHT AND VARIABLE
WINDS EXCEPT PERHAPS ALONG THE E-COAST. RADIATIONAL COOLING LIKELY
TO PREVAIL ACROSS INTERIOR NEW ENGLAND. WILL PUSH TEMPERATURES DOWN
BY SEVERAL DEGREES LOWER THAN THE CONSENSUS FORECASTING WOULD
SUGGEST. LOWS DOWN INTO THE LOW-40S. MAY NEED TO MONITOR FOR THE
POTENTIAL OF FROST/FREEZE HEADLINES TOWARDS SUNDAY MORNING.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGHLIGHTS...
* DRY AND WARMING TREND SUN AND MON
* SHOWERS AT TIMES MIDDLE OF NEXT WEEK
* TEMPS NEXT WEEK AT OR WARMER THAN NORMAL
OVERVIEW... BOTH 00Z ECENS AND 00Z GEFS ENSEMBLES IN VERY GOOD
AGREEMENT THRU NEXT WEEK ON THE LARGE SCALE FLOW PATTERN ACROSS
NORTH AMERICA. THUS FORECAST CONFIDENCE IS PERIOD IS ABOVE AVERAGE.
RIDGING OVER THE OHIO VALLEY NORTHWARD INTO THE EASTERN GREAT
LAKES/ONTARIO AND QUEBEC 12Z SUN SLIDES EAST INTO NEW ENGLAND THRU
MON. THIS PROVIDES DRY WEATHER ALONG WITH A WARMING TREND. BY 12Z
TUE ENSEMBLES IN GOOD AGREEMENT THAT MEAN LONG WAVE RIDGE AXIS IS
CENTERED OVER NEW ENGLAND AND BEGINNING TO DRIFT OFFSHORE. HOWEVER
WITH NEXT UPSTREAM MEAN TROUGH AXIS JUST APPROACHING THE GREAT
LAKES...DRY WEATHER MAY LINGER INTO MUCH OF TUE. 12Z DETERMINISTIC
RUNS ARE MORE BULLISH/FASTER WITH UPSTREAM TROUGH. HOWEVER AT THIS
TIME RANGE ENSEMBLES SHOULD VERIFY BETTER. A MODEL BLEND DEPICTS
THIS NICELY SO WILL FOLLOW ACCORDINGLY.
BY WED AND THU OF NEXT WEEK MEAN MID LEVEL TROUGH AXIS IS OVER THE
REGION YIELDING A HIGH RISK OF SCATTERED AFTERNOON/EVENING SHOWERS.
AS FOR THE RISK OF STRONG CONVECTION...THE GEFS ENSEMBLES INDICATING
LITTLE IF ANY CAPE OVER NEW ENGLAND WITH BEST INSTABILITY WEST
ACROSS NY/PA AND NJ. HENCE WARM SECTOR REMAINS SOUTH AND WEST OF THE
AREA. HOWEVER GIVEN THE TIME RANGE HERE CAN/T RULE OUT TSTMS
ESPECIALLY INTO WESTERN NEW ENGLAND BUT WILL LEAVE OUT OF THE
FORECAST FOR NOW GIVEN THE UNCERTAINTY ON POSITION OF WARM FRONT.
BY LATE NEXT WEEK MEAN TROUGH BEGINS TO DEAMPLIFY AND EJECTS
NORTHEAST OUT OF NEW ENGLAND. THUS SOME IMPROVEMENT/ DRYING TREND IS
POSSIBLE LATE NEXT WEEK.
DAILY DETAILS...
SUNDAY...
REAL NICE DAY WITH HIGH PRES IN CONTROL BRINGING DRY CONDITIONS AND
LIGHT WINDS. CHILLY TO START THE DAY /40S/ BUT STRONG JUNE SUNSHINE
WILL MODIFY THE AIRMASS WITH HIGHS WARMING WELL INTO THE 70S. COOLER
AT THE COAST GIVEN AFTERNOON SEABREEZES.
MONDAY...
HIGH PRES SHIFTS TO THE S OF NEW ENG WITH SW FLOW AND ASSOCIATED LOW
LEVEL WARM ADVECTION YIELDING HIGHS IN THE U70S TO L80S EXCEPT
COOLER ALONG THE SOUTH COAST GIVEN WIND TRAJECTORY OFF THE COOLER
OCEAN WATERS.
TUESDAY THROUGH THURSDAY...
MEAN MID LEVEL TROUGH AND ASSOCIATED SURFACE LOW EXITS THE GREAT
LAKES AND TRACKS INTO SOUTHEAST CANADA WITH ITS FRONTAL BOUNDARY
INTO NEW ENGLAND. ENSEMBLES SUGGEST DEEP LAYER RIDGING MAY LINGER
LONG ENOUGH FOR DRY WEATHER TO PERSIST INTO TUE ESPECIALLY ACROSS RI
AND EASTERN MA. HOWEVER BY WED AND THU ENSEMBLES AGREE MEAN TROUGH
AXIS WILL BE OVER THE AREA...THUS HIGHEST RISK FOR SHOWERS
/ESPECIALLY AFTERNOON AND EARLY EVENING/ WILL BE WED AND THU. AS
FOR TEMPS...GIVEN ALL MODEL DATASETS SUGGEST TRUE WARM SECTOR
REMAINS SOUTH AND WEST OF NEW ENGLAND...COOLEST TEMPS WILL BE ACROSS
EASTERN MA AND WARMEST IN THE CT RVR VLY. IN FACT MODELS HINTING A
POSSIBLE BACKDOOR COLD FRONT WED/THU POTENTIALLY IMPACTING
NORTHEAST MA. THUS COOLER THAN NORMAL CONDITIONS POSSIBLE FOR THIS
AREA. GIVEN THE TIME RANGE HERE AND MESOSCALE ASPECTS OF BACKDOOR
FRONT WILL NOT TRY TO INDICATE COOLER TEMPS AND JUST KEEP AN EYE
ON LATER MODEL RUNS.
FRIDAY...
ENSEMBLES SUGGEST MEAN MID LEVEL TROUGH DEAMPLIFIES AND EJECTS
NORTHEAST AWAY FROM NEW ENGLAND. THIS SHOULD REDUCE THE RISK OF
SHOWERS...HENCE DRYING TREND POSSIBLE HERE ALONG WITH TEMPS AT LEAST
SEASONABLY WARM.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
.SHORT-TERM /INTO SUNDAY MORNING/...MODERATE CONFIDENCE.
SCT SHRA/TSRA WILL MAKE FOR TEMPO MVFR-IFR CONDITIONS ACROSS THE
INTERIOR. SOME OF THESE STORMS MAY CONTAIN GUSTY WINDS AND SMALL
HAIL. DUE TO UNCERTAINTY...WILL PREVAIL WITH VCTS FOR INTERIOR
TERMINALS WHERE CONFIDENCE IS HIGHEST. ALL OTHER TERMINALS UNDER
THE INFLUENCE OF A SEA-BREEZE WITH BRISK EASTERLY FLOW.
ACTIVITY DIMINISHING OVERNIGHT BEHIND A COLD FRONT. WIDELY SCT
SHRA LINGER INTO SATURDAY...SWEEPING E TO W DURING THE EARLY-HALF
OF THE DAY. ACTIVITY CONCLUDES TOWARDS THE LATER-HALF OF SATURDAY.
VFR UNDER BREEZY NE-WINDS WITH GUSTS UP TO 25 KTS. WINDS DIMINISH
INTO SUNDAY MORNING WITH HIGH PRES. DENSE IFR-LIFR FOG POSSIBLE
ACROSS THE INTERIOR.
KBOS TAF...MODERATE CONFIDENCE IN TAF. WILL KEEP TSRA OUT OF THE
TAF WITH ONSHORE E-WINDS. SHRA MAY LINGER INTO EARLY SATURDAY
MORNING.
KBDL TAF...MODERATE CONFIDENCE IN TAF. SHRA/TSRA EXPECTED...YET
EXACTING TIMING OF IMPACTS WILL BE DEALT WITH THROUGH AMENDMENTS.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
SUNDAY/MONDAY...HIGH CONFIDENCE FOR VFR AND DRY WEATHER. SEABREEZES
SUN AFTERNOON.
TUESDAY/WEDNESDAY...MODERATE CONFIDENCE. VFR TO START BUT LIKELY
LOWERING TO MVFR IN SCT SHOWERS TUE NIGHT INTO WED FROM WEST TO EAST.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
.SHORT-TERM /INTO SUNDAY MORNING/...MODERATE CONFIDENCE.
E/SE FLOW PREVAILING THIS EVENING AHEAD OF A COLD FRONT WHICH WILL
SWEEP INTO THE WATERS OVERNIGHT. SHOWERS WILL ENTER THE WATERS
AHEAD OF THE COLD FRONT WITH LOWER CONFIDENCE OF THUNDERSTORMS.
WITH COLD FRONTAL PASSAGE...WINDS BACK OUT OF THE NE AND INCREASE
TOWARDS LATE SATURDAY INTO SATURDAY NIGHT. WINDS OF 10 TO 15 KTS
WITH GUSTS UP TO 25 KTS POSSIBLE HAVE RESULTED IN THE ISSUANCE OF
SMALL-CRAFT ADVISORIES. WAVES BUILDING TO 5 FEET MAY LINGER INTO
SUNDAY EVEN THOUGH WINDS WILL DIMINISH UNDER INCREASING HIGH PRES.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
SUNDAY...HIGH CONFIDENCE. FINE BOATING WEATHER WITH HIGH PRES
OVER THE WATERS. LITTLE IF ANY WIND WAVES ALONG WITH GOOD VSBY AND
DRY WEATHER. ONLY POSSIBLE ISSUE WILL BE LEFTOVER 4-6 FT EASTERLY
SWELLS MAINLY CONFINED TO THE SOUTH AND EAST WATERS OF NANTUCKET.
MONDAY...HIGH CONFIDENCE CONTINUES AS HIGH PRES SLOWLY SLIDES SOUTH
OF NEW ENGLAND YIELDING SW WINDS. LEFTOVER EAST SWELLS 3-6 FT MAY
PERSIST OVER EASTERN OUTER OCEAN WATERS.
TUESDAY...MODERATE CONFIDENCE. S/SE FLOW GETS UNDERWAY AHEAD OF
APPROACHING WARM FRONT. SPEEDS SHOULD REMAIN LESS THAN 20 KT.
WEDNESDAY...LOW TO MODERATE CONFIDENCE. WARM FRONT APPROACHES WITH
AN INCREASED RISK OF SHOWERS AND PERHAPS A TSTM OVER THE SOUTHERN
WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM SATURDAY TO 2 AM EDT SUNDAY
FOR ANZ231>235-237.
SMALL CRAFT ADVISORY FROM 2 PM TO 8 PM EDT SATURDAY FOR ANZ236.
SMALL CRAFT ADVISORY FROM 11 AM SATURDAY TO 8 AM EDT SUNDAY
FOR ANZ254>256.
&&
$$
SYNOPSIS...NOCERA/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...NOCERA
AVIATION...NOCERA/SIPPRELL
MARINE...NOCERA/SIPPRELL
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
216 PM EDT FRI MAY 30 2014
.SYNOPSIS...
A SLOW MOVING FRONTAL SYSTEM WILL BE IN THE FORECAST
AREA THROUGH TONIGHT. THE FRONT WILL BE JUST SOUTH OF THE AREA
SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE UPPER-LEVEL LOW WILL REMAIN IN THE LOWER MISSISSIPPI RIVER
VALLEY THROUGH TONIGHT. FARTHER EAST...OUR REGION WILL BE UNDER
A WEAK RIDGE. THE MODELS INDICATE A SHORTWAVE TROUGH CAUGHT IN
THIS RIDGE NEAR THE FORECAST AREA. THE LATEST ANALYSIS SHOWED H5
TEMPERATURES RELATIVELY COLD AROUND -10 C. AN EAST-WEST ORIENTED
FRONTAL SYSTEM WILL REMAIN IN THE FORECAST AREA. CONVERGENCE
ASSOCIATED WITH THE FRONT AND DIFFERENCES IN HEATING BECAUSE OF
CLOUD-COVER GRADIENTS PLUS THE COLD TEMPERATURES ALOFT WILL HELP
CAUSE THUNDERSTORMS. THE CLOUDINESS GRADIENT IN THE CSRA CAUSED
THE INITIAL DEVELOPMENT IN THE CSRA EARLY THIS AFTERNOON.
LITTLE MOVEMENT WILL OCCUR BECAUSE OF THE UPPER-LEVEL RIDGE SO
EXPECT LIMITED THUNDERSTORM COVERAGE. ALSO...CLOUDINESS OVER MUCH
OF THE AREA HAS LIMITED INSTABILITY. THE HIGH-RESOLUTION MODELS
SUPPORT JUST SCATTERED COVERAGE. THE HRRR DISPLAYS THE GREATEST
COVERAGE IN THE CSRA LATE THIS AFTERNOON.
THE MAIN FORECAST PROBLEM WILL BE THUNDERSTORMS WITH THE
POTENTIAL FOR HEAVY RAIN BECAUSE OF PRECIPITABLE WATER NEAR 1.8
OF AN INCH AND SLOW STORM MOVEMENT. NEAR-SEVERE WIND GUSTS MAY
OCCUR BECAUSE OF HEAVY PRECIPITATION LOADING.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
WEAK SURFACE COLD FRONT WILL CONTINUE SLOWLY SOUTHWARD ACROSS THE
FORECAST AREA SATURDAY...PUSHING INTO SOUTHERN GEORGIA SATURDAY
NIGHT. GFS HOLDS ON TO 1.75 PRECIPITABLE WATER VALUES INTO LATE
SATURDAY NIGHT WHILE THE NAM DRIES OUT A LITTLE QUICKER. FRONTAL
FORCING WITH POSSIBLE RESIDUAL OUTFLOW BOUNDARY INTERACTION WILL
PRODUCE SCATTERED SHOWERS AND THUNDERSTORMS SATURDAY AFTERNOON
INTO SATURDAY EVENING MAINLY SOUTH OF I-20 SOUTH AND WEST OF I-26.
CURRENT POPS LOOK GOOD WITH 30-40 POPS ACROSS CENTRAL AND SOUTHERN
PORTIONS...20 OR LESS NORTH. SPC HAS THIS REGION IN GENERAL
THUNDER SO NOT EXPECTING STORMS TO REACH SEVERE LEVELS. HOWEVER
WITH WEAK WINDS ALOFT PERSISTING AND RESULTING SLOW MOVING
CELLS...THE POTENTIAL FOR LOCALIZED HEAVY RAINFALL WILL CONTINUE.
NEAR NORMAL TEMPERATURES IN THE MIDDLE 80S FOR AFTERNOON HIGHS
WITH OVERNIGHT LOWS IN THE MIDDLE 60S.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
UPPER LEVEL RIDGING ACROSS THE EASTERN US WILL DOMINATE EARLY IN
THE PERIOD BEFORE FLATTENING OUT IN RESPONSE TO A SERIES OF TROFS
SWEEPING EAST ACROSS THE NORTHEASTERN US STARTING MID WEEK. MAINLY DRY
SUNDAY THROUGH TUESDAY UNDER RIDGE. WEAK SURFACE FRONT APPROACHES
FORECAST AREA LATE TUESDAY INCREASING POPS BY MID WEEK. RIBBON OF
GULF MOISTURE ON WEST SIDE OF HIGH JUST OFF SE COAST WILL AID IN
CONVECTION DEVELOPMENT ALONG FRONTAL BOUNDARY. MODELS HINT AT
WEAKENING FRONT SO SHOWER AND THUNDERSTORM ACTIVITY PROBABLY LIMITED
AS FRONT MOVES ACROSS FORECAST AREA LATE TUESDAY INTO WEDNESDAY. OTHERWISE
FORECAST AREA STAYS IN LIGHT UPPER FLOW THROUGH THE EXTENDED
PERIOD AS MAIN TROF ENERGY STAYS WELL NORTH. SCATTERED DIURNALLY
DRIVEN CONVECTION FROM THURSDAY ON. NEAR NORMAL TEMPERATURES FIRST
HALF OF THE PERIOD...WARMING TO SLIGHTLY ABOVE NORMAL SECOND HALF.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AN EAST-WEST ORIENTED FRONTAL SYSTEM WILL REMAIN IN THE FORECAST
AREA THROUGH THE TAF PERIOD. CONVERGENCE ASSOCIATED WITH THE
FRONT AND DIFFERENCES IN HEATING BECAUSE OF CLOUD-COVER GRADIENTS
PLUS RELATIVELY COLD TEMPERATURES ALOFT WILL HELP CAUSE
THUNDERSTORMS. THE CLOUDINESS GRADIENT IN THE CSRA CAUSED THE
INITIAL DEVELOPMENT IN THE CSRA EARLY THIS AFTERNOON. THE HRRR
SUPPORTS THE GREATEST THUNDERSTORM CHANCE IN THE CSRA 20 TO 22Z.
THE CHANCE OF IMPACTS MAY BE GREATEST AT AGS AND DNL DURING THAT
TIME.
PRECIPITABLE WATER IS HIGH WITH VALUES NEAR 1.8 OF AN INCH. VERY
HEAVY DOWNPOURS MAY OCCUR WITH ANY THUNDERSTORMS. HEAVY
PRECIPITATION LOADING MAY LEAD TO VERY STRONG WINDS NEAR ANY
THUNDERSTORMS.
HIGH LOW-LEVEL MOISTURE...WEAK FRONTAL CONVERGENCE AND NOCTURNAL
COOLING WILL LIKELY LEAD TO WIDESPREAD STRATUS AND FOG DURING THE
EARLY MORNING HOURS. MOST OF NAM AND GFS MOS INDICATE A PERIOD OF
IFR CONDITIONS. HEATING AND MIXING SHOULD BRING IMPROVEMENT LATER
IN THE MORNING SATURDAY.
EXTENDED AVIATION OUTLOOK...MOISTURE ASSOCIATED WITH THE REMNANTS
OF A STALLED FRONT WILL CONTINUE DURING MUCH OF THE OUTLOOK
PERIOD. EXPECT RESTRICTIONS AT TIMES MAINLY FROM AFTERNOON AND
EVENING THUNDERSTORMS AND EARLY MORNING STRATUS AND FOG.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
155 PM EDT FRI MAY 30 2014
.SYNOPSIS...
A SLOW MOVING FRONTAL SYSTEM WILL BE IN THE FORECAST
AREA THROUGH TONIGHT. THE FRONT WILL BE JUST SOUTH OF THE AREA
SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE UPPER-LEVEL LOW WILL REMAIN IN THE LOWER MISSISSIPPI RIVER
VALLEY THROUGH TONIGHT. FARTHER EAST...OUR REGION WILL BE UNDER
A WEAK RIDGE. THE MODELS INDICATE A SHORTWAVE TROUGH CAUGHT IN
THIS RIDGE NEAR THE FORECAST AREA. THE LATEST ANALYSIS SHOWED H5
TEMPERATURES RELATIVELY COLD AROUND -10 C. AN EAST-WEST ORIENTED
FRONTAL SYSTEM WILL REMAIN IN THE FORECAST AREA. CONVERGENCE
ASSOCIATED WITH THE FRONT AND DIFFERENCES IN HEATING BECAUSE OF
CLOUD-COVER GRADIENTS PLUS THE COLD TEMPERATURES ALOFT SHOULD LEAD
TO THUNDERSTORMS. THE CLOUDINESS GRADIENT IN THE CSRA THIS MORNING MAY
BE FOCUS FOR THE INITIAL DEVELOPMENT OF THUNDERSTORMS THIS AFTERNOON.
LITTLE MOVEMENT WILL OCCUR BECAUSE OF THE UPPER-LEVEL RIDGE SO
EXPECT LIMITED THUNDERSTORM COVERAGE. THE HIGH-RESOLUTION MODELS
SUPPORT SCATTERED COVERAGE. THE CAE AND SPC WRF SUPPORT
THUNDERSTORMS BEGINNING AROUND 400 PM WITH THE GREATEST COVERAGE
TONIGHT MAINLY BETWEEN 700 PM AND 1000 PM. THE HRRR DISPLAYS
ISOLATED COVERAGE BEGINNING AROUND 300 PM WITH VERY LITTLE
COVERAGE THROUGH 700 PM.
THE MAIN FORECAST PROBLEM WILL BE THUNDERSTORMS WITH THE
POTENTIAL FOR HEAVY RAIN BECAUSE OF PRECIPITABLE WATER NEAR 1.8
OF AN INCH AND SLOW STORM MOVEMENT. NEAR-SEVERE WIND GUSTS MAY
OCCUR BECAUSE OF HEAVY PRECIPITATION LOADING AND THE POSSIBILITY
OF MODERATE INSTABILITY IF THERE ARE ENOUGH BREAKS IN THE
CLOUDINESS AND MORE HEATING CAN OCCUR.
&&
.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
WEAK SURFACE COLD FRONT WILL CONTINUE SLOWLY SOUTHWARD ACROSS THE
FORECAST AREA SATURDAY...PUSHING INTO SOUTHERN GEORGIA SATURDAY
NIGHT. GFS HOLDS ON TO 1.75 PRECIPITABLE WATER VALUES INTO LATE
SATURDAY NIGHT WHILE THE NAM DRIES OUT A LITTLE QUICKER. FRONTAL
FORCING WITH POSSIBLE RESIDUAL OUTFLOW BOUNDARY INTERACTION WILL
PRODUCE SCATTERED SHOWERS AND THUNDERSTORMS SATURDAY AFTERNOON
INTO SATURDAY EVENING MAINLY SOUTH OF I-20 SOUTH AND WEST OF I-26.
CURRENT POPS LOOK GOOD WITH 30-40 POPS ACROSS CENTRAL AND SOUTHERN
PORTIONS...20 OR LESS NORTH. SPC HAS THIS REGION IN GENERAL
THUNDER SO NOT EXPECTING STORMS TO REACH SEVERE LEVELS. HOWEVER
WITH WEAK WINDS ALOFT PERSISTING AND RESULTING SLOW MOVING
CELLS...THE POTENTIAL FOR LOCALIZED HEAVY RAINFALL WILL CONTINUE.
NEAR NORMAL TEMPERATURES IN THE MIDDLE 80S FOR AFTERNOON HIGHS
WITH OVERNIGHT LOWS IN THE MIDDLE 60S.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
UPPER LEVEL RIDGING ACROSS THE EASTERN US WILL DOMINATE EARLY IN
THE PERIOD BEFORE FLATTENING OUT IN RESPONSE TO A SERIES OF TROFS
SWEEPING EAST ACROSS THE NORTHEASTERN US STARTING MID WEEK. MAINLY DRY
SUNDAY THROUGH TUESDAY UNDER RIDGE. WEAK SURFACE FRONT APPROACHES
FORECAST AREA LATE TUESDAY INCREASING POPS BY MID WEEK. RIBBON OF
GULF MOISTURE ON WEST SIDE OF HIGH JUST OFF SE COAST WILL AID IN
CONVECTION DEVELOPMENT ALONG FRONTAL BOUNDARY. MODELS HINT AT
WEAKENING FRONT SO SHOWER AND THUNDERSTORM ACTIVITY PROBABLY LIMITED
AS FRONT MOVES ACROSS FORECAST AREA LATE TUESDAY INTO WEDNESDAY. OTHERWISE
FORECAST AREA STAYS IN LIGHT UPPER FLOW THROUGH THE EXTENDED
PERIOD AS MAIN TROF ENERGY STAYS WELL NORTH. SCATTERED DIURNALLY
DRIVEN CONVECTION FROM THURSDAY ON. NEAR NORMAL TEMPERATURES FIRST
HALF OF THE PERIOD...WARMING TO SLIGHTLY ABOVE NORMAL SECOND HALF.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AN EAST-WEST ORIENTED FRONTAL SYSTEM WILL REMAIN IN THE FORECAST
AREA THROUGH THE TAF PERIOD. MOISTURE ASSOCIATED WITH THE FRONT HAS
HELPED SUPPORT MAINLY MVFR CEILINGS THIS MORNING. HEATING SHOULD
HELP RAISE CEILINGS...BUT CONVERGENCE ASSOCIATED WITH THE FRONT
AND DIFFERENCES IN HEATING BECAUSE OF CLOUD-COVER GRADIENTS PLUS
COLD TEMPERATURES ALOFT SHOULD LEAD TO THUNDERSTORMS. THE CLOUDINESS
GRADIENT IN THE CSRA THIS MORNING MAY BE FOCUS FOR THE INITIAL
DEVELOPMENT OF THUNDERSTORMS THIS AFTERNOON.
SLOW STORM MOVEMENT BECAUSE OF THE UPPER-LEVEL RIDGING WILL HELP
LIMIT COVERAGE. THE HIGH-RESOLUTION MODELS SUPPORT SCATTERED
COVERAGE. THE CAE AND SPC WRF SUPPORT THUNDERSTORMS BEGINNING
AROUND 400 PM WITH THE GREATEST COVERAGE TONIGHT MAINLY BETWEEN
700 PM AND 1000 PM. THE HRRR DISPLAYS ISOLATED COVERAGE BEGINNING
AROUND 300 PM WITH VERY LITTLE COVERAGE THROUGH 700 PM.
THUNDERSTORMS MAY BEGIN EARLIER IN THE AFTERNOON AND AFFECT AGS
AND DNL BECAUSE OF THE DIFFERENTIAL HEATING OCCURRING ALONG THE
CLOUD GRADIENT THIS MORNING NEAR THE SAVANNAH RIVER.
PRECIPITABLE WATER WILL BE HIGH WITH VALUES NEAR 1.8 OF AN INCH.
VERY HEAVY DOWNPOURS MAY OCCUR WITH ANY THUNDERSTORMS. HEAVY
PRECIPITATION LOADING AND POSSIBLY MODERATE INSTABILITY IF THERE
ARE ENOUGH BREAKS IN THE CLOUDINESS MAY LEAD TO VERY STRONG WINDS
NEAR ANY THUNDERSTORMS.
EXTENDED AVIATION OUTLOOK...MOISTURE ASSOCIATED WITH THE REMNANTS
OF A STALLED FRONT WILL CONTINUE DURING MUCH OF THE OUTLOOK
PERIOD. EXPECT RESTRICTIONS AT TIMES MAINLY FROM AFTERNOON AND
EVENING THUNDERSTORMS AND EARLY MORNING STRATUS AND FOG.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
87
AREA FORECAST DISCUSSION
NWS POCATELLO ID
210 PM MDT FRI MAY 30 2014
.SHORT TERM...TONIGHT THROUGH MONDAY. WV SAT IMAGERY SHOWS
SHORTWAVE CIRCULATION OVER NORTHEAST CALIFORNIA SLOWLY MOVING
EAST. MID LEVEL MOISTURE AHEAD OF FEATURE PUSHING INTO IDAHO THIS
AFTERNOON. SEEING SOME DESTABILIZATION OCCURRING IN THE SOUTHEAST
CORNER ROUGHLY BEAR LAKE REGION NORTH ALONG THE WYOMING BORDER
WHERE VIS SAT SHOWS SOME CU DEVELOPMENT. HRRR SHOWING SOME HINTS
OF CONVECTIVE DEVELOPMENT IN THIS REGION THIS AFTERNOON BUT
REMAINDER OF REGION REMAINS STABLE SO EXPECT CONVECTION TO
CONTINUE TO BE SUPPRESSED THIS AFTERNOON. CONVECTION REMAINS
POSSIBLE OVERNIGHT AS MODELS MAINTAIN INSTABILITY AHEAD OF
ELONGATED TROUGH THROUGH PACNW. DRY NUDGE BEHIND SHORTWAVE AND
ASSOCIATED WITH SURFACE LOW PUSHING NORTHEAST INTO EASTERN IDAHO EARLY
SATURDAY SHOULD KEEP CONVECTION CONFINED TO CENTRAL MOUNTAINS AND
AREAS NORTH EARLY MORNING BUT AIR MASS DOES REMAIN UNSTABLE
OVERNIGHT AND INTO SATURDAY. BEST MOISTURE AVAILABILITY OVER
HIGHER ELEVATIONS SATURDAY ESPECIALLY CENTRAL MOUNTAINS SO
CONCENTRATED POPS TO THE NORTH. UPPER TROUGH SWINGS OVERHEAD
SATURDAY NIGHT THEN BEGINS TO SHIFT EAST SUNDAY. LEFT POPS IN
PLACE WHERE BEST INSTABILITY SHOWN BY MODELS. FLOW FLATTENS
CONSIDERABLY SUNDAY NIGHT AND TRANSITIONS TO WEAK RIDGE DURING THE
DAY MONDAY. DRIER AIR MASS IN PLACE AT THAT TIME BEHIND TROUGH SO
KEPT POPS BELOW CLIMO FOR THOSE PERIODS.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY.
GFS KEEPS GENERAL TROF PATTERN ALOFT OVER EASTERN IDAHO WITH A
CHANCE OF SHOWERS PRETTY MUCH DAILY. EUROPEAN TRANSITIONS TO DRIER
ZONAL FLOW BY LAT WEDNESDAY INTO THURSDAY AND IS DRIER LATE IN THE
LONG TERM PERIOD. FOR NOW KEPT IN SOME DAILY SHOWERS WITH SOME
LOWER CHANCES BY FRIDAY. TEMPERATURES ARE EXPECTED TO BE SLIGHTLY
ABOVE NORMAL THROUGH THE PERIOD ESPECIALLY IF THE SUSTAINED MORE
SOUTHERLY FLOW PATTERN ON THE GFS VERIFIES. FOR NOW DID NOT ALTER
PREVIOUS GRIDS EXTENSIVELY AND KEPT THE GENERAL TREND OF NEAR
CLIMATOLOGICAL POPS.
GK
&&
.AVIATION...SOUTHERLY FLOW USHERING IN EXTENSIVE MIDDLE AND HIGH
LEVEL CLOUDS. EXPECT VFR CONDITIONS THROUGH SATURDAY. A WEAK WAVE
IS FORECAST TO MOVE THROUGH OVERNIGHT AND KEPT IN VICINITY SHOWERS
AT ALL TAF SITES AT ABOUT THE MIDNIGHT LOCAL TIME FRAME. LOW LEVELS
STILL DRY SO NOT SURE IF ANY WILL REACH THE SURFACE. EXPECT
CONVECTION TO DEVELOP SATURDAY AFTERNOON AS WELL. SHOULD BE MAINLY
LIGHT WINDS THROUGH THE PERIOD.
GK
&&
.HYDROLOGY...HAVE UPDATED RIVER STATEMENT TO HIGHLIGHT INCREASED
FLOWS THROUGH TETON BASIN WITH GAGES AT OR JUST ABOVE BANK FULL
THROUGH THE WEEKEND. HAVE ALSO USED THE OPPORTUNITY TO HIGHLIGHT
INCREASED FLOWS IN TRIBUTARY CREEKS THROUGH TETON VALLEY LEADING
TO TETON RIVER. DMH
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
341 PM CDT FRI MAY 30 2014
.SYNOPSIS...
ISSUED AT 336 PM CDT FRI MAY 30 2014
12Z UA ANALYSIS HAS THE CLOSED UPPER LOW OVER THE LOWER MISSISSIPPI
VALLEY WITH HIGH PRESSURE OVER THE GREAT LAKES. SATELLITE/RADAR
TRENDS THROUGH MID AFTERNOON SHOW PLENTY OF DIURNAL CLOUDS WITH
CONVECTION FROM SOUTHERN ILLINOIS THROUGH NORTHEAST MISSOURI AND
INTO PARTS OF SOUTHERN IOWA.
18Z SFC ANALYSIS HAD HIGH PRESSURE FROM THE GREAT LAKES INTO THE
SOUTHERN PLAINS WITH SOME INFERRED WEAK BOUNDARIES OVER THE LOWER
MISSISSIPPI AND OHIO VALLEYS. DEW POINTS WERE MAINLY IN THE 60S
ACROSS THE MIDWEST AND PLAINS WITH 50S ACROSS THE GREAT LAKES.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 336 PM CDT FRI MAY 30 2014
BASED ON SATELLITE...RADAR...AND RAP TRENDS...THE CONVECTION FROM
SOUTHERN ILLINOIS INTO NORTHEAST MISSOURI AND SOUTHERN IOWA WILL NOT
MAKE MUCH MORE NORTHERN PROGRESS THROUGH LATE AFTERNOON. THUS AREAS
SOUTH OF A KOTM TO KSPI LINE WILL HAVE THE BEST CHANCE OF SEEING
ISOLATED TO POSSIBLY SCATTERED STORMS.
AFTER SUNSET...THE REMAINING CONVECTION WILL DISSIPATE BY 10-11 PM
ALONG WITH THE REMAINING DIURNAL CLOUDS. THE REMAINDER OF THE NIGHT
WILL BE QUIET AND DRY.
QUIET AND DRY CONDITIONS WILL BE SEEN INITIALLY SATURDAY MORNING
ACROSS THE AREA. NEW DIURNAL CLOUDS WILL BEGIN DEVELOPING BY LATE
MORNING WITH SOME CONVECTION ACROSS THE FAR WEST BY MID DAY.
CONVECTION WILL INCREASE IN AREAL COVERAGE SATURDAY AFTERNOON ACROSS
THE WESTERN HALF OF THE AREA AS BETTER MOISTURE MOVES INTO THE AREA.
EAST OF THE MISSISSIPPI DRY CONDITIONS ARE EXPECTED SATURDAY
AFTERNOON.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 336 PM CDT FRI MAY 30 2014
CONVECTION THAT DEVELOPS ACROSS THE WESTERN HALF OF THE AREA WILL
SLOWLY DISSIPATE SATURDAY EVENING WITH SUNSET. MAINLY DRY CONDITIONS
ARE EXPECTED FROM LATE SATURDAY NIGHT THROUGH SUNRISE SUNDAY.
INCREASING MOISTURE RETURN ON SUNDAY WITH A WEAK DISTURBANCE ALOFT
WILL ALLOW NEW CONVECTION TO DEVELOP BY LATE MORNING AND INCREASE IN
AREAL COVERAGE DURING THE AFTERNOON HOURS. THIS CONVECTION IS
EXPECTED TO CONTINUE INTO SUNDAY EVENING BEFORE DISSIPATING.
SUNDAY NIGHT AND INTO MONDAY THE MODELS ARE SUGGESTING AN ORGANIZED
THUNDERSTORM COMPLEX DEVELOPING IN EASTERN NEBRASKA AND MOVING EAST.
IF CORRECT...THIS THUNDERSTORM COMPLEX WOULD ARRIVE IN THE AREA VERY
LATE SUNDAY NIGHT AND MOVE ACROSS THE AREA MONDAY MORNING AS IT
DISSIPATES. BOUNDARIES LEFT OVER FROM THIS COMPLEX WOULD THEN
PROVIDE THE FOCUS FOR NEW CONVECTION DEVELOPING MONDAY AFTERNOON.
MONDAY NIGHT ON...
THERE ARE DIFFERENCES AMONG THE MODELS AS TO WHAT WILL OCCUR MONDAY
NIGHT THROUGH TUESDAY. THE ECMWF/GEM SUGGEST HIGH PRESSURE BUILDING
IN BRINGING AN END TO THE RAIN. THE GFS KEEPS RAIN ACROSS THE AREA.
WEIGHING THE STRENGTHS/WEAKNESSES OF THE MODELS AND CONSIDERING THE
OVERALL SYNOPTIC PICTURE...THE IDEA OF BRINGING IN A DRYING TREND
LATE MONDAY NIGHT AND TUESDAY DOES HAVE MERIT.
TUESDAY NIGHT THROUGH FRIDAY...THE MODEL CONSENSUS HAS CHANCE POPS
EACH DAY. THE OVERALL SYNOPTIC PICTURE SUGGESTS A POTENTIALLY ACTIVE
PATTERN WITH AN EAST/WEST BOUNDARY SETTING UP IN OR CLOSE TO THE
AREA. WILL IT RAIN CONTINUOUSLY THE ENTIRE TIME. NO. EACH ROUND OF
CONVECTION WILL DICTATE WHERE SUBSEQUENT ROUNDS OF CONVECTION WILL
DEVELOP. SO...THERE WILL BE PERIODS OF DRY WEATHER FROM TUESDAY
NIGHT THROUGH FRIDAY. ATTEMPTING TO PIN THEM DOWN IS NOT POSSIBLE
WHEN DEALING WITH NONLINEAR PROCESSES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1229 PM CDT FRI MAY 30 2014
VFR CONDITIONS WILL BE SEEN THROUGH 18Z/31 WITH HIGH PRESSURE
REMAINING OVER THE GREAT LAKES. DIURNAL SHRA/TSRA WILL BE SEEN
ACROSS SOUTHEAST IOWA BUT SHOULD BE MORE THAN 10SM AWAY FROM KBRL.
NEW DIURNAL CONVECTION IS EXPECTED TO DEVELOP AFT 18Z/31 ACROSS
IOWA THAT MIGHT AFFECT KCID.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...08
SHORT TERM...08
LONG TERM...08
AVIATION...08
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1233 PM CDT FRI MAY 30 2014
.UPDATE...
ISSUED AT 1229 PM CDT FRI MAY 30 2014
DIURNAL CONVECTION HAS DEVELOPED ACROSS MISSOURI INTO SOUTHERN
ILLINOIS. BASED ON SATELLITE AND RAP TRENDS...THE AREAL COVERAGE
OF THE CONVECTION THIS AFTERNOON SHOULD NOT BE AS EXTENSIVE AS
FORECAST. THUS POPS HAVE BEEN REDUCED AND PULLED A BIT MORE TO THE
SOUTH AND WEST. CONVECTION SHOULD BECOME QUITE ISOLATED BY EARLY
EVENING AND DISSIPATE BY 04Z.
UPDATE ISSUED AT 1047 AM CDT FRI MAY 30 2014
DIURNAL CLOUDS HAVE DEVELOPED ACROSS MISSOURI AND SOUTHERN
ILLINOIS WITH JUST A HINT OF DIURNAL CLOUDS STARTING TO DEVELOP
FROM KVYS TO KALO.
BASED ON SATELLITE TRENDS...THE SLIGHT CHANCE POPS FOR ISOLATED
CONVECTION IN THE FAR SOUTH HAS BEEN REMOVED FOR LATE MORNING AND
MID DAY.
THE QUESTION THEN TURNS TO HOW WIDESPREAD WILL DIURNAL CONVECTION
BE IN THE FAR SOUTH/SOUTHWEST THIS AFTERNOON. FOR NOW WILL KEEP
THE CURRENT SLIGHT CHANCE/CHANCE POPS IN PLACE BUT INSTINCT TELLS
ME THAT THE AREAL COVERAGE AND POPS FOR THIS AFTERNOON NEEDS TO BE
LOWERED.
&&
.SYNOPSIS...
ISSUED AT 255 AM CDT FRI MAY 30 2014
HIGH PRESSURE WAS SITUATED ACROSS THE GREAT LAKES REGION PROVIDING
CLEAR SKIES AND LIGHT EAST WINDS TO THE DVN CWA. A SUBTLE FRONTAL
BOUNDARY EXTENDED FROM THE OHIO VALLEY TO NORTHERN MO. DRIER AIR
WAS NOTED IN OUR NE CWA WITH DEWPOINTS IN THE LOWER TO MID 50S
WHILE IN OUR SW CWA THE DEWPOINTS WERE IN THE MID 60S. THIS WAS
HAVING AN IMPACT ON CURRENT TEMPERATURES WHICH AT 2 AM RANGED FROM
56 AT FREEPORT TO 70 IN OUR WESTERN CWA. AN UPPER LEVEL LOW PRESSURE
SYSTEM WAS NEARLY STATIONARY IN THE LOWER MS VALLEY AS SEEN ON WATER
VAPOR LOOPS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 255 AM CDT FRI MAY 30 2014
FORECAST FOCUS ON CHANCE OF SHOWERS AND THUNDERSTORMS IN OUR SW
CWA TODAY.
TODAY...HIGH PRESSURE ACROSS THE GREAT LAKES WILL FEED DRIER
EASTERLY WINDS INTO OUR NORTHEAST HALF CWA. THIS WILL PROVIDE SUNNY
SKIES AND COMFORTABLY WARM TEMPERATURES. A DIFFERENT STORY IN OUR
SW HALF WHERE BETTER MOISTURE WITH DEWPOINTS IN THE 60S ALLOWING
FOR SBCAPES TO APPROACH 2000 J/KG. FORECAST SOUNDINGS INDICATE
LITTLE IF ANY CAPPING SO ONCE THE CONVECTIVE TEMPERATURE IN THE
LOWER TO MID 80S IS REACHED CUMULUS CLOUDS SHOULD FORM RAPIDLY.
ISOLATED TO SCATTERED PULSE THUNDERSTORMS WILL ALSO POP UP BY
EARLY TO MID AFTERNOON AND I WILL MAINTAIN THE 20-40 POPS THROUGH
THE AFTERNOON HOURS. WITH RATHER LIGHT WINDS ALOFT AND PRECIPITABLE
WATERS OF AROUND 1.50 INCHES THESE STORMS WILL PRODUCE LOCALLY
HEAVY RAINFALL. STORM MOTION SHOULD BE FROM THE EAST AT AROUND
8-10 KNOTS. MAXIMUM TEMPERATURES WILL BE IN THE LOWER TO MID 80S.
TONIGHT...WITH LOSS OF HEATING ANY LINGERING SHOWERS OR STORMS IN
OUR SW CWA WILL QUICKLY END BY EARLY THIS EVENING...FOLLOWED BY
CLEAR TO PARTLY CLOUDY SKIES. MINIMUM TEMPERATURES WILL RANGE FROM
THE MID 50S NE TO THE MID 60S SW.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 255 AM CDT FRI MAY 30 2014
A QUIET START TO THE WEEKEND WILL OPEN THE DOOR TO UNSETTLED WEATHER
NEXT WEEK BEGINNING SUNDAY. TEMPERATURES WILL AVERAGE A FEW DEGREES
ABOVE NORMAL DURING THE PERIOD.
SOUTHEAST LOW-LEVEL FLOW OVER THE AREA SATURDAY WILL BECOMING MORE
SOUTHERLY SUNDAY AS A WARM FRONT AND THERMAL-MOISTURE FEED PROGRESS
THROUGH THE CWA. DIURNALLY DRIVEN THUNDERSTORMS OF A NON-SEVERE
NATURE ARE THE MAIN CONCERN...SO THE DAY WILL NOT BE A TOTAL WASHOUT
BY ANY MEANS.
PASSAGE OF AN UPPER TROUGH WITH A SURFACE LOW PRESSURE SYSTEM MOVING
NORTH OF THE AREA MONDAY WILL MAINTAIN RAIN CHANCES THROUGH THE DAY
AND OVERNIGHT INTO TUESDAY. DIFFERENCES IN THE GFS AND ECMWF BEGIN
TO APPEAR AT THIS TIME WITH THE GFS FAVORING A FASTER TROUGH PASSAGE
DURING THE DAYTIME AND THE ECMWF A SLOWER SOLUTION. ITS HARD TO
FIND A GOOD REASON TO FAVOR ONE MODEL VS. THE OTHER...SO WILL NOT
GET TOO SPECIFIC ON THE DETAILS. HOWEVER...CAPE/SHEAR VALUES
SUGGEST SEVERE WEATHER IS A POSSIBILITY...IF THE ATMOSPHERE IS NOT
AS MOIST AS THE ECMWF IS FORECASTING.
MODEL DISCREPANCIES CONTINUE THE REMAINDER OF THE WEEK AS THE COLD
FRONT MENTIONED ABOVE BECOMES QUASI-STATIONARY SETTING UP POTENTIAL
MCS ACTIVITY IN OR NEAR THE CWA TUESDAY NIGHT INTO THURSDAY. THE
GFS TENDS TO KEEP THE FRONTAL BOUNDARY CLOSER TO THE CWA WHILE THE
ECMWF KEEPS IT DOWN IN MISSOURI...WHICH CLIMATOLOGY WOULD TEND TO
FAVOR. AGAIN HOWEVER THERE IS LITTLE REASON TO FAVOR ONE MODEL OVER
THE OTHER SO WILL NOT GET TOO DETAILED IN THE FORECAST. WHEREVER
MCSS FIRE OFF...CAPE/SHEAR PROGS SUGGEST A SEVERE POTENTIAL UNLESS
THE ATMOSPHERE AGAIN IS TOO MOIST...WHICH HAPPENS TO BE ANOTHER
POINT OF DISAGREEMENT BETWEEN THE TWO MODELS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1229 PM CDT FRI MAY 30 2014
VFR CONDITIONS WILL BE SEEN THROUGH 18Z/31 WITH HIGH PRESSURE
REMAINING OVER THE GREAT LAKES. DIURNAL SHRA/TSRA WILL BE SEEN
ACROSS SOUTHEAST IOWA BUT SHOULD BE MORE THAN 10SM AWAY FROM KBRL.
NEW DIURNAL CONVECTION IS EXPECTED TO DEVELOP AFT 18Z/31 ACROSS
IOWA THAT MIGHT AFFECT KCID.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...HAASE
SHORT TERM...HAASE
LONG TERM...WOLF
AVIATION...08
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1145 AM MDT FRI MAY 30 2014
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 249 AM MDT FRI MAY 30 2014
EARLY MORNING WV IMAGERY AND RAP H5 SHOW REX BLOCK PATTERN IN PLACE
OVER CENTRAL US WITH RIDGE OVER NORTHERN MISSISSIPPI RIVER VALLEY
AND CLOSED LOW OVER SOUTHERN MISSISSIPPI RIVER VALLEY. UPSTREAM
A POSITIVELY TILTED TROUGH EXTENDS FROM WESTERN CANADA AND ALONG
THE WESTERN US COAST WITH SOUTHWEST FLOW EXTENDING FROM THE EASTER
PACIFIC OCEAN ACROSS THE GREAT BASIN AND CENTRAL ROCKIES. A PLUME
OF HIGH WV IS IN PLACE ACROSS THE ROCKIES AND SOUTHERN PLAINS
ORIGINATING MAINLY FROM THE WESTERN GULF OF MEXICO.
ACTIVE PATTERN IS STILL ANTICIPATED THROUGH THIS WEEKEND AS A
SERIES OF SHORTWAVE TROUGHS EMBEDDED WITHIN THE THE SW TRANSLATE
NORTH AND EAST ACROSS THE CENTRAL ROCKIES INTO THE NORTHERN
PLAINS. TRACK WOULD GENERALLY FAVOR LOCATIONS WEST AND NORTH FOR
BETTER THUNDERSTORM COVERAGE...HOWEVER GUIDANCE CONTINUES TO SHOW
GOOD LIFT/MOISTURE/INSTABILITY IN PLACE OVER OUR CWA. HIGHER
TERRAIN IN COLORADO AND SURFACE TROUGH PROGGED TO LINGER AROUND
THE KS/CO STATE LINE WILL BE PRIMARY LOCATION FOR INITIATION FOR
THIS AFTERNOON/TONIGHT AND AGAIN ON SATURDAY. BETTER
LIFT/INSTABILITY IS PROGGED ON SUNDAY/SUNDAY NIGHT ACROSS THE
CWA...WITH SOME GUIDANCE SHOWING A SHIFT IN FLOW TO WEST-EAST AS
BLOCK FINALLY BREAKS DOWN. NOT A LOT OF CERTAINTY REGARDING THE
EXACT EVOLUTION OF THE PATTERN...HOWEVER GUIDANCE CONTINUES TO
SHOW GOOD SUPPORT FOR THUNDERSTORM ACTIVITY ACROSS THE CWA. SHEER
PROFILES GENERALLY WOULDNT SUPPORT MUCH MORE THAN SLOW MOVING
THUNDERSTORM CLUSTERS THROUGH SUNDAY...HOWEVER THERE IS ALSO THE
POTENTIAL FOR FASTER MOVING COLD POOL DOMINANT CLUSTERS (AS NAM IS
GENERALLY SHOWING) WHICH SHOULD TAKE ON MORE OF A EASTERN MOTION.
WITH MODERATE INSTABILITY IN PLACE THERE IS ALSO THE POSSIBLY FOR
A FEW ISOLATED STORMS PRODUCING MARGINALLY SEVERE HAIL...OTHERWISE
IT SEEMS WIND AND LOCALLY HEAVY RAIN WOULD BE THE MAIN CONCERN.
I FELT COMFORTABLE BUMPING UP POPS...ESPECIALLY THIS EVENING AND
SUNDAY/SUNDAY NIGHT IN THE NW WHERE MODELS ARE SHOWING BETTER
CONSISTENCY. DUE TO COMPLICATIONS OF SKY/WX CONFIDENCE IS LOWER ON
TEMPS AND WIND...SO I LEANED TOWARDS A MEAN BLEND WHICH STILL
REFLECTS ABOVE NORMAL TEMPS AND SEASONALLY BREEZY DAYTIME WINDS.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 249 AM MDT FRI MAY 30 2014
AN ACTIVE WEATHER PATTERN IS AHEAD FOR THE TRI STATE AREA IN THE
LONG TERM FORECAST...WITH CHANCES FOR SHOWERS AND THUNDERSTORMS EACH
DAY IN THE PERIOD. MODELS ARE COMING INTO BETTER AGREEMENT REGARDING
THE SHORTWAVE RIDGE DEVELOPING OVER THE HIGH PLAINS MONDAY INTO
TUESDAY WITH SOUTHWESTERLY TO WESTERLY FLOW ALOFT. THE SUBSIDENCE
ALOFT SHOULD KEEP CONDITIONS MOSTLY DRY TUESDAY...HOWEVER WITH
AFTERNOON HIGH TEMPERATURES APPROACHING CONVECTIVE TEMPERATURES OVER
THE REGION...CAP COULD BREAK IN THE WESTERN PORTIONS OF THE FORECAST
AREA IN THE AFTERNOON AND EVENING HOURS TUESDAY.
THE UPPER LEVEL RIDGE WILL BEGIN TO BREAK DOWN WEDNESDAY AS A
SHORTWAVE RIDGE TROUGH CLIPS THE NORTHERN PORTION OF THE AREA FOR
WEDNESDAY. MODELS DIFFER SOMEWHAT IN REGARD TO THE MOISTURE
AVAILABILITY AT THE MID AND UPPER LEVELS FOR WEDNESDAY. WITH UPPER
LEVEL LOW PRESSURE SYSTEM IN PLACE OVER THE WESTERN CONUS...SOME
GUIDANCE SUGGESTS MOISTURE WILL BE SOMEWHAT FUNNELED INTO THE AREA
FROM THE PACIFIC AS UPPER LEVEL PROFILES IN MODEL SOUNDINGS SHOW
AMPLE MOISTURE FOR STORM DEVELOPMENT. IN OTHER INSTANCES...THE
SOUTHWEST FLOW ALOFT WILL TAP DRY DESERT AIR AND BRING PLENTY OF DRY
AIR ALOFT...WHICH COULD POTENTIALLY BRING FIRE WEATHER CONCERNS IF
MIXING TAKES PLACE. JUST LEFT SOME POPS IN THE FORECAST WITH SOME
INSTABILITY PRESENT IN MODEL FORECASTS...BUT CONVECTION REALLY
DEPENDS ON WHETHER THE MOIST OR DRY SOLUTIONS PAN OUT FOR WEDNESDAY.
THE APPROACHING SHORTWAVE WILL PROVIDE PRIME LOCATIONS FOR LIFT OVER
THE AREA THURSDAY AT THE MID AND LOWER LEVELS SOMEWHERE OVER THE
HIGH PLAINS...WHICH WILL BRING STORM DEVELOPMENT WITH BETTER
MOISTURE AVAILABILITY AT THE LOWER AND THE MID LEVELS. BEST LOCATION AT
THE MOMENT SHOULD BE EAST OF US HIGHWAY 83...BUT MODEL AGREEMENT TO
EXACT PLACEMENT OF THE LIFT REMAINS POOR.
TEMPERATURES TO START THE PERIOD WILL BE SLIGHTLY ABOVE AVERAGE
BEFORE A SURFACE COLD FRONT MOVES THROUGH THE AREA WEDNESDAY. COOLER
AIR WILL THEN MOVE INTO THE PLAINS IN THE UPPER 70S...WHICH IS MORE
IN LINE WITH NORMAL TEMPERATURES FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1135 AM MDT FRI MAY 30 2014
VFR CONDITIONS THROUGH MOST OF THE PERIOD WITH CONVECTIVE SHOWERS
AND THUNDERSTORMS EXPECTED OVER BOTH TERMINALS THIS AFTERNOON AND
TONIGHT INTO TOMORROW. A SHORTWAVE TROUGH MOVING OVER THE CENTRAL
ROCKIES WILL MAKE ITS WAY INTO THE HIGH PLAINS THIS AFTERNOON.
THUNDERSTORMS HAVE ALREADY BEGUN TO DEVELOP IN EASTERN COLORADO
AND WILL CONTINUE TO DEVELOP AND SLOWLY PUSH NORTHEAST AND EAST.
EXACT TIMING OF THUNDERSTORMS OVER THE TERMINALS IS A LITTLE
QUESTIONABLE SO WENT WITH A TEMPO GROUP FOR KGLD BETWEEN 22Z AND
02Z THIS AFTERNOON AND FOR KMCK BETWEEN 03Z AND 05Z TONIGHT.
AS SHOWERS AND THUNDERSTORMS SLOWLY MOVE EAST ALONG A FRONTAL
BOUNDARY...THE CHANCE FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE END OF THE TAF PERIOD. THUNDERSTORMS COULD BECOME
MARGINALLY SEVERE WITH HAIL...GUSTY OUTFLOW WINDS...AND LOCALLY
HEAVY RAINFALL THAT COULD REDUCE VISIBILITY TEMPORARILY. THIS IS
NOT INCLUDED IN THE TAF DUE TO THE DISCRETE LOCATION OF CONVECTIVE
CELLS...BUT IT IS SOMETHING TO PAY ATTENTION TO IF THESE
CONDITIONS DEVELOP.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...MK
AVIATION...ALW
AREA FORECAST DISCUSSION
NWS JACKSON KY
306 PM EDT FRI MAY 30 2014
.UPDATE...
ISSUED AT 940 AM EDT FRI MAY 30 2014
MINOR UPDATE THIS MORNING TO FRESHEN UP ZONE WORDING...REMOVE MENTION
OF FOG. ALSO TWEAKED GRIDS TO LATEST HOURLY OBS. OTHERWISE FORECAST
APPEARED IN PRETTY GOOD SHAPE. EXPECTING ISOLD TO SCATTERED SHOWERS
AND THUNDERSTORMS TO FIRE WITH DIURNAL HEATING AND BACKDOOR COLD
FRONTAL BOUNDARY SERVING AS A FOCUS. HRRR SUGGESTS ACTIVITY SHOULD
BEGIN TO FIRE BETWEEN 16-17Z GENERALLY SOUTHWEST OF A MOUNT STERLING
TO PAINTSVILLE LINE WITH THE BEST COVERAGE ACROSS THE SOUTHWEST.
UPDATE ISSUED AT 7 AM EDT FRI MAY 30 2014
FRESHENED UP THE GRIDS A BIT THIS MORNING USING THE LATEST OBS AND
MODEL DATA. SOME EARLY MORNING VALLEY FOG...DENSE IN PLACES...SHOULD
BE GONE BY 9 OR 930 THIS MORNING. FORECAST STILL ON TRACK WITH
SCATTERED SHOWERS AND STORMS EXPECTED TO DEVELOP BY MID MORNING AND
LAST THROUGH LATE THIS AFTERNOON BEFORE EXITING THE AREA EARLY THIS
EVENING. STILL EXPECTING A WARM AND MUGGY DAY WITH HIGHS IN THE LOW
TO MID 80S ACROSS THE BOARD. NO MAJOR CHANGES ARE ANTICIPATED WITH
THE FORECAST FOR THE REST OF TODAY...SO NO UPDATE IS PLANNED AT THIS
TIME.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 307 AM EDT FRI MAY 30 2014
THE MODELS WERE IN PRETTY GOOD AGREEMENT IN THE SHORT TERM. THE
GENERAL CONSENSUS IS FOR THE AREA TO REMAIN RAIN FREE UNTIL AROUND
SUNRISE TODAY. ONCE THE SUN IS UP ISOLATED SHOWERS AND STORMS SHOULD
BEGIN FIRING ACROSS THE SOUTHERN HALF OF THE FORECAST AREA...AS A
WEAK COLD FRONT MOVES SLOWLY SOUTHWARD ACROSS CENTRAL AND EASTERN
KENTUCKY. THE MOST ACTIVE PERIOD SHOULD BE FROM AROUND 15Z THIS
MORNING THROUGH AROUND 20Z THIS AFTERNOON. MOST OF THE PRECIPITATION
WE ARE EXPECTING TODAY SHOULD OCCUR PRIMARILY ALONG AND SOUTH OF THE
HAL ROGERS PARKWAY AND HIGHWAY 80 CORRIDOR. THE FRONT IS EXPECTED TO
EXIT THE AREA...ALONG WITH ANY PRECIPITATION ASSOCIATED WITH
IT...AROUND 1Z THIS EVENING. AFTER THAT...A STRONG RIDGE OF HIGH
PRESSURE WILL SETTLE ACROSS THE REGION...BRINGING ABOVE NORMAL
TEMPERATURES AND MOSTLY SUNNY SKIES TO THE AREA TO BEGIN THE WEEKEND.
HIGH TEMPERATURES THE NEXT COUPLE OF DAYS WILL TOP OUT IN THE LOW TO
MID 80S...WITH OVERNIGHT LOWS IN THE 60S.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 306 PM EDT FRI MAY 30 2014
MODELS REMAIN IN DECENT AGREEMENT THROUGH MUCH OF THE EXTENDED. IT
LOOKS LIKE THE SOUTHEASTERN CONUS RIDGE WILL BUILD AGAIN FROM LATE
IN THE WEEKEND INTO EARLY NEXT WEEK...WITH MOISTURE AND ASSOCIATED
INSTABILITY INCREASING ONCE AGAIN. THIS WILL BRING RENEWED CHANCES
FOR SHOWERS AND PERHAPS A THUNDERSTORM AS WE HEAD INTO SUNDAY
AFTERNOON...BUT ESPECIALLY BY MONDAY AFTERNOON. SHOWER AND STORM
CHANCES WILL LIKELY BE TIED TO THE DIURNAL CYCLE...MEANING QUIET
NIGHTS SHOULD PREVAIL.
BY TUESDAY A SHORTWAVE TROUGH WILL PUSH ACROSS THE OHIO RIVER
VALLEY SUPPRESSING THE HIGH OFF TO THE SOUTH. THIS WILL PROVIDE A
BETTER PERIOD OF UNSETTLED WEATHER AS THIS FEATURE MOVES ACROSS THE
AREA ON TUESDAY. FOR THIS REASON...OPTED TO GO WITH LIKELY POPS.
HIGH PRESSURE WILL THEN BUILD ACROSS THE AREA FOR WEDNESDAY AND
THURSDAY...WITH MORE ISOLATED SHOWERS OR THUNDERSTORMS POSSIBLE IN
THE AFTERNOON/EARLY EVENING HOURS. THE NEXT SIGNIFICANT SHORTWAVE
WILL ARRIVE LATE IN THE WEEK...AND MODELS ARE TRENDING SLOWER WITH
THE SYSTEM...SO IT MAY BE MORE OVER THE WEEKEND...PROVIDING ANOTHER
SHOT AT MORE WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY.
HIGHS THROUGH THE PERIOD SHOULD BE RATHER STEADY WITH READINGS IN
THE LOW TO MID 80S EACH AFTERNOON...AND LOWS GENERALLY IN THE 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 740 AM EDT FRI MAY 30 2014
JKL...SJS...AND LOZ WILL CONTINUE TO SEE REDUCED VSBYS AND CIGS DUE
TO FOG THROUGH 13Z OR SO THIS MORNING. THE FOG IS QUICKLY DISSIPATING
AT JKL AND LOZ...SO THOSE AIRPORTS MAY BE IN THE CLEAR BY 830. SJS
HAS BEEN SOCKED IN ALL NIGHT...AS THAT SITE MAY NOT BE FREE OF FOG
UNTIL 14Z. ONCE SCATTERED SHOWERS AND STORMS ARE EXPECTED TO FIRE UP
BY AROUND 15Z AND WILL LIKELY LAST THROUGH LATE THIS AFTERNOON. DUE
TO THE SCATTERED NATURE OF THE STORMS TODAY...THE TAF SITES WILL
PROBABLY NOT BE AFFECTED DIRECTLY...BUT DID USE VCTS FOR LOZ AND SME
IN CASE A STORM STRAYS NEAR EITHER AIRPORT. ASIDE FROM THAT...VFR
CONDITIONS WILL PREVAIL THROUGH MOST OF THE TAF PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RAY
SHORT TERM...AR
LONG TERM...KAS
AVIATION...AR
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1251 PM CDT FRI MAY 30 2014
.AVIATION...
UPPER LOW OVER NW LA...WITH SCATTERED SHOWERS OF VERY HEAVY RAIN
SLOWLY CIRCULATING COUNTERCLOCKWISE ACROSS ENTIRE CWA. ALONG WITH
THESE DOWNPOURS WILL COME TEMPO PERIODS OF IFR CIGS AND
VSBYS...WITH RETURNS TO LOW VFR CIGS BTWN SHOWERS. AREAS OF FOG
CAN BE EXPECTED TONIGHT WHERE HEAVY RAIN OCCURS TODAY...AS WINDS
REMAIN A LIGHT AND MOSTLY EASTERLY THRU PERIOD./VII/
&&
.PREV DISCUSSION... /ISSUED 1101 AM CDT FRI MAY 30 2014/
DISCUSSION...
RADAR IMAGERY REVEALS THAT THE MID LEVEL LOW IS CENTERED JUST W OF
SHV THIS MORNING...WITH THE UPPER LOW STRETCHED FARTHER NE OVER
SCNTRL AR. SFC OBS AND VISIBLE SATELLITE IMAGERY ALSO DEPICT A
WEAK SFC LOW FARTHER SW OVER E TX JUST SW OF TYR...WITH AN
ATTENDANT SFC TROUGH EXTENDING NE TO ALONG THE AR/LA LINE...WHICH
HAS RESULTED IN INCREASED CONVERGENCE FOR SCT CONVECTION TO
DEVELOP TO ITS N. POCKETS OF LOCALIZED HEATING OVER WRN AND NCNTRL
LA HAS RESULTED IN AGITATED CU TOWERS...WITH WIDELY SCT CONVECTION
JUST NOW BEGINNING TO DEVELOP OVER THESE AREAS. THE 12Z NAM HAS
INITIALIZED WELL ON THE E TX SFC LOW THIS MORNING...AND WEAKENS
IT THROUGH THE AFTERNOON...WITH THE CONVECTION MORE MESOSCALE
DRIVEN ESPECIALLY OVER N LA/SW AR/SE OK/EXTREME NE TX ON THE E
SIDE OF THE MID LEVEL LOW...WHICH SHOULD PERHAPS ONLY DRIFT A TAD
FARTHER W THROUGH THE AFTERNOON. THE LATEST HRRR HAS INITIALIZED WELL ON
THE ONGOING CONVECTION THIS MORNING...WITH ADDITIONAL DEVELOPMENT
LIKELY ESPECIALLY AS ADDITIONAL HEATING IS ADDED WITHIN A VERY
MOIST ENVIRONMENT. DID MAKE SOME MINOR ADJUSTMENTS TO POPS MAINLY
FOR THIS MORNING PER CURRENT RADAR TRENDS...AND DID LOWER POPS A
TAD TO HIGH CHANCE ACROSS THE SRN SECTIONS OF NCNTRL LA WITH
CONVECTION EXPECTED TO BE MORE SCATTERED.
DID MAKE SOME MINOR ADJUSTMENTS TO MAX TEMPS THIS AFTERNOON...RAISING
THEM SLIGHTLY ACROSS THE SRN AND ERN SECTIONS OF NCNTRL LA WHERE
BREAKS IN THE CLOUD COVER HAVE ALLOWED 15Z TEMPS TO CLIMB INTO THE
UPPER 70S/NEAR 80 ALREADY. OTHERWISE...THE REMAINDER OF THE
FORECAST IS ON TRACK.
ZONE UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 83 68 83 69 87 / 60 40 60 30 40
MLU 84 68 84 67 86 / 60 40 60 30 40
DEQ 81 67 81 68 84 / 60 40 60 30 40
TXK 79 66 82 68 84 / 60 40 60 30 40
ELD 82 67 81 67 84 / 60 40 60 30 40
TYR 82 68 82 68 85 / 40 40 40 20 40
GGG 82 68 83 68 86 / 50 40 40 30 40
LFK 85 69 85 69 87 / 60 40 40 20 40
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
659 PM EDT FRI MAY 30 2014
.AVIATION...
//DISCUSSION...
CLEAR SKIES WILL HOLD THROUGH THE FORECAST PERIOD. LIGHT NORTHEAST
FLOW THROUGH THIS EVENING WILL VEER TO THE SOUTHEAST BY MORNING. FOR
AIRFIELDS CLOSER TO THE WATER...LIGHT SOUTHEAST WINDS ASSOCIATED
WITH THE LAKE BREEZE WILL CONTINUE AFFECTING KDTW, KYIP, AND KDET
FOR THE NEXT FEW HOURS BEFORE DISSIPATING.
//DTW THRESHOLD THREATS...
* NONE.
&&
.PREV DISCUSSION...ISSUED 335 PM EDT FRI MAY 30 2014
SHORT TERM... REST OF TODAY THROUGH TONIGHT
SURFACE ANALYSIS INDICATES HIGH PRESSURE IS RELATIVELY WEAK OVER
LOWER MICHIGAN TODAY IN ADVANCE OF A WEAK BACKDOOR COLD FRONT OVER
NORTHERN LAKE HURON THAT MARKS THE LEADING EDGE OF STRONGER HIGH
PRESSURE OVER NORTHERN ONTARIO. THE LOWER MICHIGAN HIGH PRESSURE IS
WEAK BUT IS IN FULL CONTROL OF THE WEATHER ACROSS THE REGION AND
WILL PROVIDE A SUNNY SKY THROUGH THE EARLY EVENING WITH TEMPERATURES
SETTLING OFF HIGHS AROUND 80. THE USUAL EXCEPTION IS ALONG THE
SHORELINES WHERE COOLER READINGS WILL BE ENSURED BY THE LAKE BREEZE.
FARTHER INLAND...THE WEAK PRESSURE GRADIENT IS SUSCEPTIBLE TO
MODIFICATION BY DIFFERENTIAL HEATING BETWEEN LAND AND WATER WHICH
REPRESENTS ABOUT THE ONLY OTHER NOTABLE ASPECT OF THE WEATHER WORTH
DISCUSSION. LOWER SURFACE PRESSURE OVER INLAND AREAS WILL QUICKLY
FILL TOWARD SUNSET AND OPEN THE DOOR FOR A NOTICEABLE INLAND RELEASE
OF THE LAKE BREEZE. IN THIS CASE...THE PROCESS WILL BE A HYBRID OF
DIFFERENTIAL HEATING LOSS AND THE BACKDOOR FRONT WASHING OUT AS IT
ENTERS SE MICHIGAN LEAVING THE NET RESULT OF BUILDING HIGH PRESSURE
AFTER MIDNIGHT. BOTH THE NAM AND RAP SUGGEST A LIGHT/VARIABLE
SURFACE WIND BECOMING NE DURING THE EVENING AND THEN LINGERING
AROUND 5 KNOTS THROUGH THE NIGHT...JUST STRONG ENOUGH TO INHIBIT
RADIATIONAL COOLING COMPARED TO THE LAST COUPLE OF NIGHTS. MIN TEMPS
IN THE UPPER 40S TO LOWER 50S THEN LOOK SOLID BY SUNRISE SATURDAY.
LONG TERM...
UPPER LEVEL RIDGE CENTER (587 DAM AT 500 MB) OVER THE WESTERN GREAT
LAKES THIS MORNING WILL BE SLIDING SOUTHEAST INTO THE OHIO VALLEY
TOMORROW. INCREASING LOW LEVEL SOUTHEAST FLOW WILL TEMPER THE UPWARD
TREND IN TEMPERATURES...AND DO NOT FORESEE TOMORROW BEING MUCH
WARMER THAN TODAY...AROUND 80 DEGREES/LOWER 80S ACROSS MOST
LOCATIONS AS 850 MB TEMPS FORECASTED TO HOLD AROUND 12 C. INCREASING
SOUTHWEST FLOW ABOVE THE SURFACE ON SUNDAY WILL LEAD TO FURTHER
WARMING...AS 850 MB TEMPS RISE TO 15 C (PER 12Z UKMET WHICH LIES IN
BETWEEN THE COOLER NAM/WARMER GFS)...SUPPORTIVE OF MID
80S...ESPECIALLY WEST OF US-23...FARTHER REMOVED FROM THE BACKED
SURFACE FLOW OFF THE COLD LAKES. GOOD SURGE OF MOISTURE SUNDAY NIGHT
INTO MONDAY...AS PW VALUES RISE TOWARD 1.75 INCHES. SOME UPPER LEVEL
ENERGY/PV FROM UPPER LEVEL LOW OVER THE WESTERN GULF COAST LOOKS TO
BE SHEARING OFF TO THE NORTHEAST WITH THE INCREASING AND DEEP
SOUTHWEST FLOW...SUPPORTING A CHANCE OF SHOWERS AND THUNDERSTORMS
LATE SUNDAY NIGHT WITH THE HELP OF A MODESTLY INCREASED NOCTURNAL
LOW LEVEL JET. DEEP MOISTURE IN PLACE ON MONDAY IN UNCAPPED
ENVIRONMENT...WITH SOME SEMBLANCE OF A WARM FRONT STRADDLED ACROSS
NORTHERN LOWER MICHIGAN SHOULD BE SUFFICIENT FOR NUMEROUS
ACTIVITY...WHICH WILL LIMIT MAX TEMPS AND CORRESPONDING
INSTABILITY...AS MODELS SUGGESTING DEW PTS PUSHING INTO THE MID TO
UPPER 60S. LOOKING AT HEAVY RAIN AS MAIN HAZARD...AS 0-6 KM SHEAR
IS NOT TERRIBLY IMPRESSIVE...AROUND 20 KNOTS.
SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO CONTINUE MONDAY
NIGHT AS DEEP MOISTURE REMAINS IN PLACE AHEAD OF A SHORTWAVE
ADVANCING ACROSS THE NORTHERN GREAT LAKES. THE MOISTURE WILL BE
SHUNTED EAST OF THE AREA TUESDAY AS A COLD FRONT PASSES THROUGH.
CHANCE POPS ARE IN PLACE TUESDAY TO ACCOUNT FOR UNCERTAINTY IN TIMING OF
FRONTAL PASSAGE...THOUGH LATEST INDICATIONS ARE ANY PRECIPITATION
WOULD FAVOR THE MORNING HOURS. A PERIOD OF DRY WEATHER THEN LOOKS TO
TAKE HOLD AS BRIEF SHORTWAVE RIDGING BUILDS IN. THE PATTERN REMAINS
PROGRESSIVE THOUGH AS SHORTWAVE ENERGY EJECTS OUT OF THE PLAINS AND
MOISTURE INCREASES...SPELLING A RETURN OF PRECIP CHANCES FROM
WEDNESDAY NIGHT THROUGH THE END OF THE WEEK. TEMPERATURES LOOK TO
FLUCTUATE IN THE NEAR TO SLIGHTLY ABOVE NORMAL RANGE FROM TUESDAY
ONWARD.
MARINE...
HIGH PRESSURE WILL REMAIN ANCHORED OVER THE EASTERN GREAT LAKES
THROUGH THE WEEKEND. WEAK GRADIENT FLOW AND STABLE CONDITIONS
SUSTAINED BY THE COLD WATER WILL LEAD TO VERY LITTLE FLOW. SOME
MODEST INCREASE IN WINDS ARE EXPECTED ON SUNDAY AS WIND DIRECTION
BECOMES SOUTHERLY...WITH INCREASING MOISTURE LEADING SHOWERS AND
THUNDERSTORMS LIKELY ON MONDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....JVC
SHORT TERM...BT
LONG TERM....SF/DT
MARINE.......SF
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
335 PM EDT FRI MAY 30 2014
.SHORT TERM... REST OF TODAY THROUGH TONIGHT
SURFACE ANALYSIS INDICATES HIGH PRESSURE IS RELATIVELY WEAK OVER
LOWER MICHIGAN TODAY IN ADVANCE OF A WEAK BACKDOOR COLD FRONT OVER
NORTHERN LAKE HURON THAT MARKS THE LEADING EDGE OF STRONGER HIGH
PRESSURE OVER NORTHERN ONTARIO. THE LOWER MICHIGAN HIGH PRESSURE IS
WEAK BUT IS IN FULL CONTROL OF THE WEATHER ACROSS THE REGION AND
WILL PROVIDE A SUNNY SKY THROUGH THE EARLY EVENING WITH TEMPERATURES
SETTLING OFF HIGHS AROUND 80. THE USUAL EXCEPTION IS ALONG THE
SHORELINES WHERE COOLER READINGS WILL BE ENSURED BY THE LAKE BREEZE.
FARTHER INLAND...THE WEAK PRESSURE GRADIENT IS SUSCEPTIBLE TO
MODIFICATION BY DIFFERENTIAL HEATING BETWEEN LAND AND WATER WHICH
REPRESENTS ABOUT THE ONLY OTHER NOTABLE ASPECT OF THE WEATHER WORTH
DISCUSSION. LOWER SURFACE PRESSURE OVER INLAND AREAS WILL QUICKLY
FILL TOWARD SUNSET AND OPEN THE DOOR FOR A NOTICEABLE INLAND RELEASE
OF THE LAKE BREEZE. IN THIS CASE...THE PROCESS WILL BE A HYBRID OF
DIFFERENTIAL HEATING LOSS AND THE BACKDOOR FRONT WASHING OUT AS IT
ENTERS SE MICHIGAN LEAVING THE NET RESULT OF BUILDING HIGH PRESSURE
AFTER MIDNIGHT. BOTH THE NAM AND RAP SUGGEST A LIGHT/VARIABLE
SURFACE WIND BECOMING NE DURING THE EVENING AND THEN LINGERING
AROUND 5 KNOTS THROUGH THE NIGHT...JUST STRONG ENOUGH TO INHIBIT
RADIATIONAL COOLING COMPARED TO THE LAST COUPLE OF NIGHTS. MIN TEMPS
IN THE UPPER 40S TO LOWER 50S THEN LOOK SOLID BY SUNRISE SATURDAY.
&&
.LONG TERM...
UPPER LEVEL RIDGE CENTER (587 DAM AT 500 MB) OVER THE WESTERN GREAT
LAKES THIS MORNING WILL BE SLIDING SOUTHEAST INTO THE OHIO VALLEY
TOMORROW. INCREASING LOW LEVEL SOUTHEAST FLOW WILL TEMPER THE UPWARD
TREND IN TEMPERATURES...AND DO NOT FORESEE TOMORROW BEING MUCH
WARMER THAN TODAY...AROUND 80 DEGREES/LOWER 80S ACROSS MOST
LOCATIONS AS 850 MB TEMPS FORECASTED TO HOLD AROUND 12 C. INCREASING
SOUTHWEST FLOW ABOVE THE SURFACE ON SUNDAY WILL LEAD TO FURTHER
WARMING...AS 850 MB TEMPS RISE TO 15 C (PER 12Z UKMET WHICH LIES IN
BETWEEN THE COOLER NAM/WARMER GFS)...SUPPORTIVE OF MID
80S...ESPECIALLY WEST OF US-23...FARTHER REMOVED FROM THE BACKED
SURFACE FLOW OFF THE COLD LAKES. GOOD SURGE OF MOISTURE SUNDAY NIGHT
INTO MONDAY...AS PW VALUES RISE TOWARD 1.75 INCHES. SOME UPPER LEVEL
ENERGY/PV FROM UPPER LEVEL LOW OVER THE WESTERN GULF COAST LOOKS TO
BE SHEARING OFF TO THE NORTHEAST WITH THE INCREASING AND DEEP
SOUTHWEST FLOW...SUPPORTING A CHANCE OF SHOWERS AND THUNDERSTORMS
LATE SUNDAY NIGHT WITH THE HELP OF A MODESTLY INCREASED NOCTURNAL
LOW LEVEL JET. DEEP MOISTURE IN PLACE ON MONDAY IN UNCAPPED
ENVIRONMENT...WITH SOME SEMBLANCE OF A WARM FRONT STRADDLED ACROSS
NORTHERN LOWER MICHIGAN SHOULD BE SUFFICIENT FOR NUMEROUS
ACTIVITY...WHICH WILL LIMIT MAX TEMPS AND CORRESPONDING
INSTABILITY...AS MODELS SUGGESTING DEW PTS PUSHING INTO THE MID TO
UPPER 60S. LOOKING AT HEAVY RAIN AS MAIN HAZARD...AS 0-6 KM SHEAR
IS NOT TERRIBLY IMPRESSIVE...AROUND 20 KNOTS.
SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO CONTINUE MONDAY
NIGHT AS DEEP MOISTURE REMAINS IN PLACE AHEAD OF A SHORTWAVE
ADVANCING ACROSS THE NORTHERN GREAT LAKES. THE MOISTURE WILL BE
SHUNTED EAST OF THE AREA TUESDAY AS A COLD FRONT PASSES THROUGH.
CHANCE POPS ARE IN PLACE TUESDAY TO ACCOUNT FOR UNCERTAINTY IN TIMING OF
FRONTAL PASSAGE...THOUGH LATEST INDICATIONS ARE ANY PRECIPITATION
WOULD FAVOR THE MORNING HOURS. A PERIOD OF DRY WEATHER THEN LOOKS TO
TAKE HOLD AS BRIEF SHORTWAVE RIDGING BUILDS IN. THE PATTERN REMAINS
PROGRESSIVE THOUGH AS SHORTWAVE ENERGY EJECTS OUT OF THE PLAINS AND
MOISTURE INCREASES...SPELLING A RETURN OF PRECIP CHANCES FROM
WEDNESDAY NIGHT THROUGH THE END OF THE WEEK. TEMPERATURES LOOK TO
FLUCTUATE IN THE NEAR TO SLIGHTLY ABOVE NORMAL RANGE FROM TUESDAY
ONWARD.
&&
.MARINE...
HIGH PRESSURE WILL REMAIN ANCHORED OVER THE EASTERN GREAT LAKES
THROUGH THE WEEKEND. WEAK GRADIENT FLOW AND STABLE CONDITIONS
SUSTAINED BY THE COLD WATER WILL LEAD TO VERY LITTLE FLOW. SOME
MODEST INCREASE IN WINDS ARE EXPECTED ON SUNDAY AS WIND DIRECTION
BECOMES SOUTHERLY...WITH INCREASING MOISTURE LEADING SHOWERS AND
THUNDERSTORMS LIKELY ON MONDAY.
&&
.AVIATION...ISSUED 1247 PM EDT FRI MAY 30 2014
//DISCUSSION...
VFR CONDITIONS WITH A FEW PATCHES OF HIGH CLOUDS AND LIGHT WIND WILL
PERSIST FOR THE REST OF TODAY THROUGH SATURDAY. A WEAK BACKDOOR
STYLE COLD FRONT WILL WASH OUT OVER LOWER MICHIGAN TONIGHT BUT DOES
REPRESENT THE LEADING EDGE OF REINFORCING HIGH PRESSURE THAT WILL
SPREAD OVER THE REGION. THE HIGH WILL SHIFT EASTWARD DURING SATURDAY
AND BRING LIGHT NORTHEAST WIND AROUND TO THE SOUTHEAST. THIS WILL
MASK LAKE BREEZE INFLUENCE IN THE DTW AREA AND MAY PREVENT A LAKE
BREEZE WIND SHIFT AT MBS BY LATE SATURDAY AFTERNOON.
FOR DTW... A LIGHT NORTHEAST TO LIGHT AND VARIABLE WIND WILL TURN
SOUTHEAST WITH A WIND SHIFT FROM LAKE ERIE DURING THE EARLY
EVENING...AND THEN TURN BACK TO THE NORTHEAST DUE TO A LATER RELEASE
OF LAKE BREEZE FROM LAKE HURON COMBINED WITH HIGH PRESSURE BUILDING
IN FROM THE NORTH.
//DTW THRESHOLD THREATS...
* NONE.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...BT
LONG TERM....SF/DT
MARINE.......SF
AVIATION.....BT
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
533 PM CDT Fri May 30 2014
.SHORT TERM: (Through Tonight)
Issued at 328 PM CDT Fri May 30 2014
Scattered thunderstorms have had more coverage this afternoon than
yesterday. These storms are occurring in an axis of 925-850mb
moisture convergence that shows up well in the latest runs on of the
RAP. Still expect the storms to gradually diminish early this
evening as the RAP shows the aforementioned low level forcing
weakening at the same time we will lose daytime heating. Expect the
rest of the night to be mainly dry with the potential for some
patchy fog toward morning. MOS lows in the mid-upper 60s still look
reasonable given current dewpoints.
Britt
.LONG TERM: (Saturday through Next Friday)
Issued at 328 PM CDT Fri May 30 2014
This discussion is probably starting to sound like a broken record,
but once again, not much change from the prev forecast.
Thru the weekend, expect much of the same as the past couple of
days. TSRA will develop mid to late morning and continue into the
evening before dissipating. Have therefore continued a persistence
forecast thru the weekend for POPs and temps.
Mdls are in good agreement bringing a cdfnt into the region on Mon
as an upper trof ejects into the Plains as the upper ridge finally
breaks down. This fnt shud bring TSRA to portions of the area.
Latest mdls suggest stronger upper forcing further swd than the prev
couple of days. Have therefore continued higher POPs as more than
enuf moisture and heating shud be available for convective
development. Did not spread the likely POPs too much further S due
to uncertainty of how far the fnt will drift S given the better
forcing remaining further N.
Mdl solns begin diverging much beyond Mon and have continued a
fairly persistent forecast for temps for now. Have also kept POPs in
the low to mid chance range due to differences among mdl solns.
Tilly
&&
.AVIATION: (For the 00z TAFs through 00z Saturday Evening)
Issued at 528 PM CDT Fri May 30 2014
Expect scattered showers and thunderstorms to quickly diminish
with the loss of daytime heating, similar to the last few days.
Many more places saw measurable rainfall today, only adding more
low level moisture and the potential of fog developing late
tonight. Have not added the fog yet, as want to make sure that
cloud cover will dissipate sufficiently to allow some cooling of
the atmosphere. Otherwise, rinse and repeat for tomorrow with
showers and thunderstorms redeveloping in the afternoon.
Specifics for KSTL:
Expect most of the showers will have dissipated or moved away from
the terminal by 00Z. Have some worry that we could see some fog
develop overnight due to todays rainfall, but will wait to see how
the atmosphere responds this evening. Otherwise should see showers
and thunderstorms redevelop on Saturday in unstable atmosphere.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
329 PM CDT Fri May 30 2014
.SHORT TERM: (Through Tonight)
Issued at 328 PM CDT Fri May 30 2014
Scattered thunderstorms have had more coverage this afternoon than
yesterday. These storms are occurring in an axis of 925-850mb
moisture convergence that shows up well in the latest runs on of the
RAP. Still expect the storms to gradually diminish early this
evening as the RAP shows the aforementioned low level forcing
weakening at the same time we will lose daytime heating. Expect the
rest of the night to be mainly dry with the potential for some
patchy fog toward morning. MOS lows in the mid-upper 60s still look
reasonable given current dewpoints.
Britt
.LONG TERM: (Saturday through Next Friday)
Issued at 328 PM CDT Fri May 30 2014
This discussion is probably starting to sound like a broken record,
but once again, not much change from the prev forecast.
Thru the weekend, expect much of the same as the past couple of
days. TSRA will develop mid to late morning and continue into the
evening before dissipating. Have therefore continued a persistence
forecast thru the weekend for POPs and temps.
Mdls are in good agreement bringing a cdfnt into the region on Mon
as an upper trof ejects into the Plains as the upper ridge finally
breaks down. This fnt shud bring TSRA to portions of the area.
Latest mdls suggest stronger upper forcing further swd than the prev
couple of days. Have therefore continued higher POPs as more than
enuf moisture and heating shud be available for convective
development. Did not spread the likely POPs too much further S due
to uncertainty of how far the fnt will drift S given the better
forcing remaining further N.
Mdl solns begin diverging much beyond Mon and have continued a
fairly persistent forecast for temps for now. Have also kept POPs in
the low to mid chance range due to differences among mdl solns.
Tilly
&&
.AVIATION: (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1243 PM CDT Fri May 30 2014
Have moved up VCTS to the start of the TAF period based on the
quick initiation of thunderstorms this afternoon. Will continue to
monitor trends to see if there is the need to add TEMPO groups at
any of the TAF sites in the next few hours. Any of the heavier
cores will be capable of producing brief MVFR or possibly IFR
conditions in +TSRA. Otherwise expect the thunderstorms to diminish
by 01Z leaving dry and VFR conditions. There still may be some
patchy fog developing across the area between 09-14Z which may
affect some of the TAF sites, particularly if there is rain at
them this afternoon. Then expect scattered thunderstorms to
redevelop again tomorrow afternoon.
Specifics for KSTL: Thunderstorms are in the vicinity of KSTL at
this time, and may need to add a TEMPO group there this afternoon
depending on the trends. Expect thunderstorms to die out there by
01Z with loss of daytime heating. Some 5-6SM BR may develop in the
area between 10-13Z, particularly if there is rain at the terminal
this afternoon, however I do not have enough confidence at this
point to include at the terminal. Then expect scattered
thunderstorms to redevelop again after 18Z tomorrow afternoon.
Britt
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 70 87 69 87 / 30 30 20 40
Quincy 66 84 67 84 / 30 30 20 40
Columbia 66 84 67 84 / 30 50 20 40
Jefferson City 67 84 67 85 / 30 50 20 40
Salem 67 85 67 85 / 30 20 10 40
Farmington 65 84 66 82 / 30 40 20 40
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1244 PM CDT Fri May 30 2014
.UPDATE:
Issued at 1243 PM CDT Fri May 30 2014
Scattered thunderstorms have developed in the last hour across the
central and northeastern parts of the CWA in an area of modest
low level moisture convergence per the latest run of the RAP. These
storms have developed earlier than yesterday in an area of 1500
J/kg MLCAPE with no CIN. Expect scattered thunderstorms to
continue to move to the west and northwest this afternoon with the
potential for producing very heavy downpours given the
precipitable waters of 1.7 inches. Small hail and gusty winds also
remain a threat. Going highs in the mid 80s still look reasonable.
Britt
&&
.SHORT TERM: (Through Late This Afternoon)
Issued at 342 AM CDT Fri May 30 2014
Isolated showers were occurring from Jerseyville southeast to Salem
IL early this morning with better coverage across southeast MO.
This activity was moving northwestward. The best coverage of
showers and storms this morning may occur across the southern
portion of the forecast area as weak shortwaves continue to rotate
around the persistent upper level low over southern AR and northern
LA. The best chance of showers and thunderstorms will be during the
afternoon hours as the atmosphere destabilizes due to daytime
heating. May see a little better coverage of convection this
afternoon along and just southwest of a weakening backdoor type cold
front moving slowly southwestward into northeast MO and southwest
IL. The latest HRRR model run has the best coverage of
showers/storms early this afternoon southwest of UIN and north of
COU and also southeast of STL. Highs today will be similar to
yesterday and slightly above normal with plenty of mid-high level
cloudiness along with diurnal cumulus clouds late this morning and
this afternoon.
GKS
.LONG TERM: (Tonight through Thursday)
Issued at 342 AM CDT Fri May 30 2014
With broad and slow moving ridge producing a sluggish weather
pattern over the central CONUS, persistence should provide a pretty
good first guess on upcoming sensible weather trends in most areas
heading into the weekend. Ridge axis does work east just a bit
during the weekend, but it still appears that weak disturbances
rotating around the upper low over the Gulf coast region will drift
up the east side of the ridge and into the mid-Mississippi Valley,
interacting with the weakly unstable airmass that is locked over the
area. This should mean a continued a threat of scattered showers and
thunderstorms, primarily during the afternoon and early evening
hours. We`ve used a fairly broad brush on PoPs on both Saturday and
Sunday afternoons/evenings, with the anticipation that any
fine-tuning of precipitation threat will have to wait until the
first period due to the very weak features that will be driving the
convection.
About the only location where we can rule out convection would be
extreme eastern sections of the FA on Saturday. Here, a bit of
drier air backdooring in from the east should stabilize the airmass
while the upper ridge exerts its greatest influence.
Temperatures should also reflect max/min trends of the past few days
and nights, with highs in the 80s and lows in the 60s.
Heading into the new work week, the upper ridge is forecast to
continue a slow eastward drift, which will allow a series of
shortwaves to push into the area as westerlies dip southward and
take on a more zonal look. While exact details are still a bit
sketchy, if this scenario does unfold there should be several good
chances of showers and thunderstorms in the Monday-Thursday time frame,
especially over the northern half of the FA.
With no major changes in the airmass during most of the medium
range temperatures should remain above average, with highs in the
80s and lows in the 60s.
Truett
&&
.AVIATION: (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1243 PM CDT Fri May 30 2014
Have moved up VCTS to the start of the TAF period based on the
quick initiation of thunderstorms this afternoon. Will continue to
monitor trends to see if there is the need to add TEMPO groups at
any of the TAF sites in the next few hours. Any of the heavier
cores will be capable of producing brief MVFR or possibly IFR
conditions in +TSRA. Otherwise expect the thunderstorms to diminish
by 01Z leaving dry and VFR conditions. There still may be some
patchy fog developing across the area between 09-14Z which may
affect some of the TAF sites, particularly if there is rain at
them this afternoon. Then expect scattered thunderstorms to
redevelop again tomorrow afternoon.
Specifics for KSTL: Thunderstorms are in the vicinity of KSTL at
this time, and may need to add a TEMPO group there this afternoon
depending on the trends. Expect thunderstorms to die out there by
01Z with loss of daytime heating. Some 5-6SM BR may develop in the
area between 10-13Z, particularly if there is rain at the terminal
this afternoon, however I do not have enough confidence at this
point to include at the terminal. Then expect scattered
thunderstorms to redevelop again after 18Z tomorrow afternoon.
Britt
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BILLINGS MT
343 PM MDT FRI MAY 30 2014
.SHORT TERM...VALID FOR SAT AND SUN...
OUR REGION IS AT RISK FOR SEVERE THUNDERSTORMS ON SATURDAY...WITH
LARGE HAIL...DAMAGING WINDS...HEAVY RAIN AND EVEN AN ISOLATED
TORNADO POSSIBLE. PLEASE TAKE NOTE AND BE PREPARED EVERYONE.
FOR TONIGHT...WEAK ENERGY LIFTING OUT OF THE CENTRAL ROCKIES
COMBINED WITH A STEADY INCREASE IN LOW TO MID LEVEL MOISTURE WILL
RESULT IN ISOLATED TO SCATTERED SHOWERS/TSTMS. SHOULD SEE SOME
INITIATION OVER OUR SOUTHERN MTNS BEFORE THE END OF THE AFTN...AND
AS OF 21Z THERE IS A TSTM NEAR CODY. OTHER AREA OF INTEREST IS FAR
SE MT AS REMNANT PLUME OF SUBTROPICAL MOISTURE IS PRESENT. THOUGH
GREATEST FORCING ASSOCIATED WITH CENTRAL ROCKIES SHORTWAVE SHOULD
STAY TO OUR SOUTHEAST...EXPECT SOME SHOWERS INTO CARTER COUNTY
THROUGH THE NIGHT. ALSO...ONSET OF MODEST SELY LOW LEVEL JET
SHOULD HELP KEEP THE POTENTIAL FOR A FEW SHOWERS/TSTMS COMING OFF
THE MTNS INTO OUR LOWER ELEVATIONS ONCE WE GET TO SUNSET AND
BEYOND. LATEST HRRR SUGGESTS SOME ACTIVITY LATER THIS EVENING.
TSTMS TONIGHT SHOULD BE NON-SEVERE.
ON SATURDAY...INGREDIENTS ARE COMING TOGETHER FOR A SIGNIFICANT
SEVERE WX EPISODE...WITH INCREASING LARGE SCALE ASCENT PER
APPROACHING PAC TROF...A RAPID MOISTENING OF OUR AIRMASS AS WE TAP
INTO NEAR 1 INCH PWAT AIR POOLED JUST TO OUR SE...AND VERY
FAVORABLE SHEAR AND INSTABILITY DURING THE AFTN AND EVENING.
DEWPTS INTO THE 50S AND REASONABLY LOW LCL HEIGHTS SUGGEST AN
ISOLD TORNADO IS POSSIBLE...ESPECIALLY EAST OF BILLINGS AS SFC
LOW DEVELOPS OVER NORTH CENTRAL WY. SREF SEVERE PARAMETERS
CONTINUE TO PEG OUR REGION FOR SEVERE WX TOMORROW...SO OVERALL
CONFIDENCE CONTINUES TO INCREASE.
A FEW DETAILS TO WORK OUT. SYNOPTIC ASCENT BY 12-18Z TOMORROW IN
OUR WEST SUGGESTS SOME SHOWER/TSTM ACTIVITY EARLY IN THE DAY...AND
WITH ENOUGH COVERAGE THIS COULD MUDDLE UP THE AIRMASS TO OUR WEST.
THIS SHOULD NOT BE AN ISSUE FOR OUR CENTRAL AND EAST WHERE WE
SHOULD SEE PLENTY OF TIME FOR DESTABILIZATION...AND LATEST GFS/NAM
SHOWS A BREAKING OF THE CAP IN THE BILLINGS AREA BY 2-3PM...WHICH
IS STILL A LITTLE ON THE EARLY SIDE. PER THE LONG DURATION OF
ASCENT WE COULD SEE A COUPLE ROUNDS OF CONVECTION ROLL THROUGH.
PLEASE BE READY FOR DANGEROUS WX TOMORROW FOLKS.
UPPER TROF WILL FINALLY MOVE THROUGH THE AREA SUNDAY...WHICH WILL
SEE PLENTY OF SHOWER ACTIVITY BUT WITH COOLER AIR AND LESS
INSTABILITY SO DO NOT SEE A SEVERE RISK FOR MUCH OF THE REGION.
EXCEPTION COULD BE IN OUR FAR EAST WHERE HIGHER THETA-E AIR WILL
RESIDE NEAR SFC TROF. THIS COULD BE IMPACTED BY HOW CONVECTION
EVOLVES SATURDAY NIGHT. EVEN THOUGH THEY MAY NOT BE SEVERE...WET
BULB ZERO HEIGHTS ON THE ORDER OF 3.5-5.5KFT UNDER THE UPPER TROF
SUGGEST SMALL HAIL WITH ANY STRONGER CELLS TO OUR WEST.
EXPECT HIGH TEMPS IN THE 70S TOMORROW THEN MID 60S TO LOWER 70S
ON SUNDAY. A COOLER NIGHT COMING SUNDAY NIGHT AS PCPN TAPERS OFF
AND SFC RIDGE SETTLES IN.
JKL
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
ONLY MINOR TWEAKS TO THE INHERITED EXTENDED PERIOD FORECAST ONCE
AGAIN THIS AFTERNOON. THE PATTERN REMAINS UNSETTLED THROUGHOUT
THE EXTENDED PERIOD. EVEN THOUGH PERIODIC PRECIPITATION IS
EXPECTED...TEMPERATURES SHOULD BE MAINLY ABOVE NORMAL IN PART DUE
TO WARMER OVERNIGHT LOWS.
MONDAY CONTINUES THE COOL...COMPARED TO RECENT DAYS...AND WET
TREND AS AN UPPER LOW LINGERS OVER THE NORTHEAST CORNER OF THE
STATE CIRCULATING ADDITIONAL MOISTURE INTO THE AREA. DRIER AIR
ALOFT DOES START TO GET PULLED INTO THE WEST...SO PRECIP AMOUNTS
SHOULD BE DECREASING SOME ON MONDAY.
TUESDAY SHOULD BE IN BETWEEN SYSTEMS...BUT INCREASED SUNSHINE
SHOULD TRIGGER DIURNAL SHOWERS AND THUNDERSTORMS. TEMPS WILL BE A
BIT WARMER...AND DID RAISE TEMPERATURES SLIGHTLY. ANOTHER UPPER
TROF APPEARS TO SWING THROUGH THE REGION TUESDAY NIGHT AND
WEDNESDAY...BRINGING ANOTHER IMPROVED CHANCE OF EXTENSIVE PRECIP
ACROSS THE REGION.
THE PATTERN TURNS SOMEWHAT DRIER AND ZONAL BY THURSDAY. AIRMASS
SHOULD REMAIN UNSTABLE...BRINGING CONTINUED POTENTIAL FOR AFTERNOON
AND EVENING SHOWER AND THUNDERSTORMS EACH DAY...ESPECIALLY OVER
THE MOUNTAINS. AAG
&&
.AVIATION...
WEAK ENERGY LIFTING OUT OF THE CENTRAL ROCKIES WILL SPREAD
ISOLATED TO WIDELY SCATTERED SHOWERS AND A FEW TSTMS TO THE
REGION LATE THIS AFTERNOON AND TONIGHT. LOCAL MVFR CAN BE EXPECTED
ESPECIALLY ALONG THE FOOTHILLS AND IN FAR SE MT...WITH OCCASIONAL
MTN OBSCURATIONS. ON SATURDAY...OUR REGION IS AT RISK FOR SEVERE
THUNDERSTORM ACTIVITY WITH LARGE HAIL...DAMAGING WINDS AND EVEN AN
ISOLATED TORNADO POSSIBLE. EXPECT LOCAL MVFR/IFR IN THE HEAVIER
SHOWERS. ALL TAF SITES COULD BE IMPACTED BY THUNDERSTORM ACTIVITY
ON SATURDAY...WITH THE GREATEST CHANCE OF SEVERE STORMS AFTER 18Z.
JKL
&&
.PRELIMINARY POINT TEMP/POPS...
SAT SUN MON TUE WED THU FRI
-----------------------------------------------------------
BIL 053/075 056/069 048/068 049/075 054/074 052/076 053/073
26/T 67/T 45/T 53/T 55/T 32/T 23/T
LVM 046/074 048/069 043/067 044/074 046/071 044/074 044/073
36/T 56/T 55/T 53/T 44/T 33/T 33/T
HDN 051/078 056/070 047/069 048/077 053/077 051/078 052/074
26/T 67/T 45/T 53/T 55/T 32/T 23/T
MLS 054/079 058/072 051/069 049/075 054/075 055/077 054/072
25/T 76/T 55/T 43/T 44/T 33/T 33/T
4BQ 054/080 058/072 050/070 050/075 053/075 054/077 053/073
34/T 66/T 45/T 43/T 55/T 44/T 43/T
BHK 051/076 056/071 050/067 048/072 051/072 052/074 052/070
23/T 77/T 55/T 43/T 34/T 43/T 33/T
SHR 048/080 052/071 046/069 045/075 048/072 048/073 049/072
36/T 66/T 35/T 54/T 44/T 43/T 33/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1254 PM CDT FRI MAY 30 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CDT FRI MAY 30 2014
TODAY AND TONIGHT...A SUBTROPICAL MOISTURE PLUME FROM THE
REMNANTS OF HURRICANE AMANDA MOVES EAST INTO WRN NEB THIS AFTN.
THE HRRR IS LIGHTING UP THIS AREA WITH SCATTERED TSTMS FROM 19Z
ON. THIS MAY BE AN HOUR OR TWO TOO FAST. MEANWHILE THE RAP SHOWS
K INDICES OVER 40C AND A STORM MOTION AROUND 200 DEGREES AT 8
KTS. LOCALLY HEAVY RAINFALL WOULD APPEAR POSSIBLE ACROSS SHERIDAN
COUNTY. 3 HOUR FLOOD GUIDANCE IS AROUND 2 INCHES SUGGESTING SOME
POTENTIAL FOR LOCAL FLOODING. NO FLOOD WATCH WILL BE ISSUED WITH
THIS FORECAST BUT HEAVY RAIN WORDING IS IN PLACE IN THIS GENERAL
AREA.
THE MOISTURE PLUME ADVANCES EAST A BIT OVERNIGHT BUT MORE
IMPORTANT THE SFC FRONT SAGS SOUTH AND EAST TO NEAR KVTN-KIML AND
MOISTURE WILL POOL BEHIND THIS FRONT IN CONJUNCTION WITH THE
MOISTURE PLUME ALOFT. THUS TSTM COVERAGE SHOULD INCREASE THIS
AFTN AND REMAIN FAIRLY ROBUST OVERNIGHT ACROSS WRN NEB.
THE SEVERE WEATHER CONCERN COVERS MAINLY SHERIDAN COUNTY WHERE
BULK SHEAR INCREASES TO AROUND 30 KTS. THE RAP AND NAM SUGGESTED
THE BETTER CHANCE FOR SEVERE STORMS WOULD BE JUST EAST OF THE
BLACK HILLS AND THEN SOUTH INTO SHANNON COUNTY SD.
THE TEMPERATURE FORECAST IS LITTLE CHANGED FROM THE PREVIOUS
FORECAST. SOUTHEAST WINDS ARE EXPECTED TO LIMIT VERTICAL MIXING
AND HOLD HIGHS DOWN IN THE 80S AHEAD OF THE FRONT. THE RAP AND
HRRR SHOW A DRIER SOUTHEAST FLOW WITH DEEPER MIXING AND HIGHS
NEAR 90 AND THESE MODELS BLENDED WITH THE REST PRODUCES A FCST
FOR HIGHS IN THE UPPER 80S TODAY.
LOWS TONIGHT FALL INTO THE LOWER 60S AHEAD OF THE FRONT WITH 50S
BEHIND THE FRONT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 352 AM CDT FRI MAY 30 2014
UPPER LEVEL RIDGE OF HIGH PRESSURE SHIFTS TO THE EAST COAST BY
THE END OF THE WEEKEND AS A TROUGH PUSHES ACROSS THE NORTHERN
ROCKIES. A SECOND TROUGH MOVES ACROSS THE ROCKIES AGAIN BY
MIDWEEK. THIS WILL RESULT IN AN ACTIVE WEEKEND WITH UNSETTLED
WEATHER CONTINUING INTO MID WEEK.
SEVERAL MID LEVEL DISTURBANCES WILL SLIDE ACROSS THE AREA WITH
STORMS EXPECTED TO FIRE WITH EACH WAVE. ON SATURDAY A WAVE WILL
BE CROSSING THE AREA DURING THE DAY WITH A SECONDARY WAVE
ENTERING FROM THE WEST LATE. A BRIEF DRY SLOW WILL ALLOW FOR A
FEW BREAKS IN THE CLOUDS DURING THE DAY. THE SECONDARY WAVE WILL
ARRIVE LATE WITH A LOW LEVEL JET OF 30 TO 35 KTS TO SUSTAIN
ACTIVITY OVERNIGHT.
POSSIBLE BREAK IN ACTION SUNDAY MORNING AS THE ATMOSPHERE GETS
READY FOR THE NEXT WAVE LATER IN THE DAY. FLOW BECOMES A LITTLE
MORE ZONAL...COMPARED TO THE SW FLOW FOR SATURDAY. MOISTURE IS
GOOD WITH PWATS INCREASING TO 1.50 TO AS HIGH AS 1.75 AHEAD OF
THE WAVE. THE GOOD MOISTURE WILL COMBINE WITH THE ADDED SHEAR
FROM THE MID LEVEL FLOW BEING A LITTLE MORE WESTERLY AND TEMPS
INTO THE 80S WITH EARLY SUN. THIS SETS THE STAGE FOR STRONG TO
SEVERE THUNDERSTORMS TO DEVELOP. MODELS STRUGGLING WITH THE
PLACEMENT OF THE SURFACE BOUNDARY/LOW...WITH A GENERALLY
CONSENSUS OF THE LOW TO BE IN EASTERN COLORADO OR WESTERN
KANSAS...SW OF THE CWA. THE SEVERE WEATHER WILL NOT BE THE ONLY
CONCERN...AS STORMS SHOULD BE GOOD RAIN PRODUCERS WITH LOCALLY
HEAVY RAIN.
SUNDAY NIGHT INTO MONDAY WILL BE A BRIEF BREAK IN THE ACTION AS
THE NEXT WAVE ARRIVES MONDAY AFTERNOON INTO MONDAY NIGHT. THE
TRAIN OF WAVES CONTINUES AS THE NEXT UPPER LEVEL TROUGH PUSHES
ACROSS THE ROCKIES. WHILE POPS ARE IN EVERY PERIOD IN THE
EXTENDED...THERE SHOULD BE SOME BREAKS IN THE ACTION...AND EVEN
SOME CLEARING. ALTHOUGH THE BREAKS MAYBE SHORT LIVED AND TIMING
THEM IS DIFFICULT THIS FAR OUT. AS FOR TEMPS...MORE SEASONAL
TEMPS WITH HIGHS MID 70S TO THE LOWER 80S...WHICH IS CLOSE TO
NORMAL FOR THE FIRST WEEK OF JUNE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1250 PM CDT FRI MAY 30 2014
A DISTURBANCE WILL MOVE NORTHEAST ACROSS THE AREA LATE THIS
AFTERNOON AND TONIGHT...WITH THUNDERSTORMS BECOMING MORE NUMEROUS
THIS EVENING ACROSS MOST OF WESTERN NEBRASKA. ACTIVITY WILL TRY TO
PUSH TOWARD THE CENTRAL PART OF THE STATE OVERNIGHT. CONFIDENCE IS
HIGH ENOUGH TO CARRY TSRA IN THE KLBF TAF...BUT LOWER AT KVTN SO
OPTED FOR VCTS. VFR WILL BE THE RULE...BUT MVFR OR IFR MAY BE
EXPERIENCED IN AND NEAR THUNDERSTORM ACTIVITY. WINDS WILL BE
GENERALLY BE SOUTHEAST AT 5 TO 15 KTS...BUT VARIABLE AND GUSTY
NEAR ANY STORM.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
429 PM EDT FRI MAY 30 2014
.SYNOPSIS...
A BACKDOOR COLD FRONT WILL SLOWLY CROSS THE FORECAST AREA FROM THE
NORTHEAST THROUGH SATURDAY NIGHT. HIGH PRESSURE WILL BUILD IN FROM
THE NORTHEAST LATE IN THE WEEKEND. THIS HIGH PRESSURE MOVE OFFSHORE
BY MIDWEEK...WHILE MOISTURE INCREASES OVER OUR AREA FROM THE WEST.
&&
.NEAR TERM /THROUGH SATURDAY/...
415 PM UPDATE...THROUGH THE REST OF THE AFTERNOON...EXPECT DEEP
CONVECTION FIRING ALONG AND NEAR THE BLUE RIDGE TO STEADILY SPREAD
OUT ACROSS MOST OF THE PIEDMONT ALONG OUTFLOW BOUNDARIES. FAVORED
PROPAGATION DIRECTION SEEMS TO BE SOUTH DUE TO THE SLY WINDS IN THE
LOWEST COUPLE THSD FT PER KGSP/TCLT VWP. THUS THE AREAS DIRECTLY
SOUTH OF THE BLUE RIDGE WILL SEE THE BEST COVERAGE. CONVECTION MAY
STILL DEVELOP IN THE CHARLOTTE AREA NOW THAT CIRRUS HAVE MOVED
OUT. OUTFLOW FROM THE CLUSTER MOVING SWWD FROM THE TRIAD AREA
STANDS A GOOD SHOT OF KICKING THINGS OFF DESPITE UNFAVORABLE E-SE
LLVL FLOW. STILL EXPECTING A FEW SEVERE THUNDERSTORMS...ALTHO
POTENTIAL NOT AS GREAT AS YESTERDAY...AND SLOW MOVING STORMS
SUGGEST ANOTHER FLASH FLOOD THREAT.
ONE IS HARD-PRESSED TO IDENTIFY THE REMAINS OF A SURFACE BOUNDARY
THAT SHOULD BE STRUNG OUT NW TO SE ACROSS THE WESTERN CAROLINAS...
SUCH THAT IT IS HARD TO SAY IF THIS FEATURE WILL EVEN PLAY ANY ROLE
IN ORGANIZING ANY DEEP CONVECTION. OVER THE NEXT 24 HOURS...SUBTLE
CHANGES ARE NOTED AT MID AND UPPER LEVELS...WHILE THE PATTERN DOES
NOT CHANGE SUBSTANTIALLY. A WEAK VORT LOBE OVERHEAD TODAY WILL KEEP
THE ENVIRONMENT NOT UNFAVORABLE FOR CONVECTION TO KEEP GOING AS LONG
AS INSTABILITY PERSISTS AND OUTFLOW BOUNDARIES CAN FORCE NEW
STORMS...GENERALLY INTO THE MID TO LATE EVENING. THE MODELS WANT TO
KEEP SOME COVERAGE PARTICULARLY NEAR THE BLUE RIDGE OWING TO A WEAK
UPSLOPE FLOW AT LOW LEVELS...SO THE FCST RETAINS AT LEAST A SLIGHT
CHANCE IN THE SOUTHEASTERLY UPSLOPE FAVORED AREAS THROUGH SATURDAY
MORNING. THE MODELS DO A MORE CONCERTED EFFORT IN IDENTIFYING A SW
TO NE GRADIENT OF MOISTURE ACROSS THE FCST AREA ON SATURDAY THAT
REPRESENTS WHAT IS LEFT OF THE FRONT. THAT SHOULD LEAD TO SOME
IDENTIFIABLE DIFFERENCES IN THE WEATHER BETWEEN NE GEORGIA AND
WESTERN SC...WHICH SHOULD HAVE ANOTHER DAY MUCH LIKE TODAY...TO THE
WESTERN PIEDMONT OF NC WHICH SHOULD HAVE A STRONGER NE WIND
ADVECTING COOLER AND DRIER AIR THAT WILL GREATLY INHIBIT CONVECTION
AND KEEP TEMPS BELOW NORMAL.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AT 230 PM EDT FRIDAY...ON SATURDAY EVENING AN UPPER RIDGE WILL
EXTEND FROM GA AND THE CAROLINAS...TO THE GREAT LAKES...WHILE AN
UPPER LOW WILL BE OVER SE TX...AND A MUCH DEEPER UPPER LOW WILL BE
WELL OFF THE NEW ENGLAND COAST. THE UPPER RIDGE PROGRESSES VERY
SLOWLY TO THE EAST COAST BY MONDAY...WHILE THE UPPER LOW OVER TX
FILLS...AND THE ATLANTIC UPPER LOW REMAINS NEARLY STATIONARY.
A SLOW MOVING COLD FRONT WILL MOVE ACROSS THE SAVANNAH RIVER VALLEY
SATURDAY NIGHT...WITH SUBSTANTIAL MOISTURE BEHIND IT. AN EASTERLY
LOW LEVEL FLOW COMPONENT IN THE WAKE OF THE FRONT WILL KEEP MOIST
UPSLOPE LIFT OVER THE SOUTHERN BLUE RIDGE...SUPPORTING CONTINUING
PRECIPITATION THERE....WHILE LINGERING INSTABILITY ALONG THE
BOUNDARY ITSELF SUPPORTS PRECIPIATION IN THE SAVANNAH RIVER VALLEY.
THE FRONT MOVES FARTHER INTO GA ON SUNDAY...HIGH PRESSURE ALONG THE
EASTERN SEABOARD WILL PUSH DRIER AIR SOUTHWEST INTO THE PIEDMONT OF
THE CAROLINAS. LINGERING MOISTURE WILL STILL SUPPORT CLOUD COVER AND
PRECIPITATION IN THE SAVANNAH RIVER VALLEY AND OVER THE MUCH OF THE
MOUNTAINS...THOUGH INSTABILITY WILL BE MUCH LESS WITH COOLER SURFACE
AIR MOVING IN.
MOISTURE STARTS TO SPREAD EAST AGAIN ON SUNDAY NIGHT AND MONDAY AS
SURFACE HIGH PRESSURE MOVES FROM THE EASTERN SEABOARD TO OFF THE
CAROLINA COAST...ALLOWING WARM MOIST ADVECTION FORM THE GULF TO
REACH NE GA AND THE WESTERN CAROLINAS. POPS WILL BE ALLOWED TO
SPREAD EAST AS A RESULT...AND INCREASING INSTABILITY WILL BE MORE
SUPPORTIVE OF CONVECTION ON MONDAY.
TEMPERATURES WILL TREND DOWNWARD AS THE COOLER AIR MASS SETTLE
IN...UNTIL MONDAY...WHEN WARM ADVECTION ENSUES IN SOUTHERLY FLOW ON
THE BACK SIDE OF THE DEPARTING HIGH PRESSURE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AT 230 PM EDT FRIDAY...THE EXTENDED FORECAST WILL FEATURE A
DEAMPLIFIED PATTERN...WITH A FLAT UPPER RIDGE OVER THE SOUTHEAST...
AND MOORE OR LESS ZONAL FLOW TO THE NORTH. WEAK HIGH PRESSURE WILL
BE CENTERED OFF THE CAROLINA COAST ON TUESDAY...WHILE THE REMNANTS
OF A COLD FRONT CROSS THE APPALACHIANS FROM THE WEST. RESIDUAL
MOISTURE ASSOCIATED WITH A FRONTOLYTIC ZONE OVER THE SOUTHERN
APPALACHIANS WILL SUPPORT PRECIPITATION LONG BEFORE THE FRONT
ARRIVES. THE SLOW MOVING BOUNDARY LEAVES THE AREA BY EARLY
WEDNESDAY...HOWEVER DRYING BEHIND IT IS SOMEWHAT LIMITED...AND MODEL
SOUNDINGS SHOW INSTABILITY AND LOW LEVEL MOISTER PERSISTING IN
SUBSEQUENT DAYS. TEMPERATURES WILL RUN NEAR MID SUMMER NORMALS.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...DEEP CONVECTION WILL FIRE ACROSS THE PIEDMONT INTO THE
AFTERNOON...BUT MOST LIKELY NEAR KCLT IN A WINDOW FROM 21Z TO 01Z
BASED MOSTLY ON THE HRRR AND WRF-ARW...AS WELL AS OUTFLOW SPREADING
SWWD FROM THE TRIAD AREA. STORMS COULD LINGER BEYOND THAT BUT WILL
BE LEFT OUT FOR NOW. WIND IS EXPECTED TO REMAIN S OR SE INTO THE
EVENING AWAY FROM THUNDERSTORM OUTFLOW BOUNDARIES. LATER
TONIGHT...SIMILAR TO LAST NIGHT...A WEAK UPSLOPE FLOW INTO THE
PIEDMONT SHOULD FORCE EITHER A LOW CLOUD CEILING OR LIGHT FOG. WENT
WITH A STRATUS DECK IN THE LOW END OF THE MVFR RANGE ALTHO IFR IS
NOT OUT OF THE QUESTION AROUND SUNRISE. THE CEILING WILL RISE
THROUGH THE MORNING AND SCATTER OUT BY MIDDAY. EXPECT A NE WIND ON
SATURDAY MORNING ONCE AGAIN.
ELSEWHERE...SCATTERED THUNDERSTORMS THROUGH THE EARLY EVENING WITH
TEMPORARY MVFR RESTRICTIONS. SIMILAR TO KCLT IN MOST REGARDS WITH
SLIGHT DIFFERENCES IN DETAIL. ANY PLACES WITH RAINFALL WILL BE
LIKELY TO GET A PERIOD OF FOG OVERNIGHT.
OUTLOOK...ALTHOUGH GRADUAL DRYING WILL DEVELOP FROM THE NE OVER THE
WEEKEND INTO EARLY NEXT WEEK...CONTINUED BOUNDARY LAYER MOISTURE
WILL PRODUCE ISOLATED TO SCATTERED DIURNAL CONVECTION EACH DAY...
WITH MORNING RESTRICTIONS POSSIBLE.
CONFIDENCE TABLE...
20-02Z 02-08Z 08-14Z 14-20Z
KCLT HIGH 81% HIGH 94% HIGH 81% HIGH 93%
KGSP HIGH 81% HIGH 100% HIGH 86% HIGH 82%
KAVL HIGH 92% HIGH 93% HIGH 91% HIGH 84%
KHKY MED 78% HIGH 85% HIGH 95% HIGH 90%
KGMU MED 79% HIGH 100% HIGH 89% HIGH 90%
KAND HIGH 100% HIGH 100% MED 69% HIGH 81%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JAT
NEAR TERM...PM/WIMBERLEY
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...PM/WIMBERLEY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
230 PM EDT FRI MAY 30 2014
.SYNOPSIS...
A BACKDOOR COLD FRONT WILL SLOWLY CROSS THE FORECAST AREA FROM THE
NORTHEAST THROUGH SATURDAY NIGHT. HIGH PRESSURE WILL BUILD IN FROM
THE NORTHEAST LATE IN THE WEEKEND. THIS HIGH PRESSURE MOVE OFFSHORE
BY MIDWEEK...WHILE MOISTURE INCREASES OVER OUR AREA FROM THE WEST.
&&
.NEAR TERM /THROUGH SATURDAY/...
THROUGH THE REST OF THE AFTERNOON...EXPECT DEEP CONVECTION FIRING
ALONG AND NEAR THE BLUE RIDGE TO STEADILY SPREAD OUT ACROSS THE
PIEDMONT ALONG OUTFLOW BOUNDARIES. THIN VEIL OF HIGHER CLOUDS OVER
THE CLT METRO AREA SHOULD MOVE OUT AND ALLOW MORE CONVECTION TO
DEVELOP IN THAT AREA INTO THE LATE AFTERNOON AND EARLY EVENING.
STILL EXPECTING A FEW SEVERE THUNDERSTORMS...ALTHO POTENTIAL NOT AS
GREAT AS YESTERDAY...AND SLOW MOVING STORMS SUGGEST ANOTHER FLASH
FLOOD THREAT.
ONE IS HARD-PRESSED TO IDENTIFY THE REMAINS OF A SURFACE BOUNDARY
THAT SHOULD BE STRUNG OUT NW TO SE ACROSS THE WESTERN CAROLINAS...
SUCH THAT IT IS HARD TO SAY IF THIS FEATURE WILL EVEN PLAY ANY ROLE
IN ORGANIZING ANY DEEP CONVECTION. OVER THE NEXT 24 HOURS...SUBTLE
CHANGES ARE NOTED AT MID AND UPPER LEVELS...WHILE THE PATTERN DOES
NOT CHANGE SUBSTANTIALLY. A WEAK VORT LOBE OVERHEAD TODAY WILL KEEP
THE ENVIRONMENT NOT UNFAVORABLE FOR CONVECTION TO KEEP GOING AS LONG
AS INSTABILITY PERSISTS AND OUTFLOW BOUNDARIES CAN FORCE NEW
STORMS...GENERALLY INTO THE MID TO LATE EVENING. THE MODELS WANT TO
KEEP SOME COVERAGE PARTICULARLY NEAR THE BLUE RIDGE OWING TO A WEAK
UPSLOPE FLOW AT LOW LEVELS...SO THE FCST RETAINS AT LEAST A SLIGHT
CHANCE IN THE SOUTHEASTERLY UPSLOPE FAVORED AREAS THROUGH SATURDAY
MORNING. THE MODELS DO A MORE CONCERTED EFFORT IN IDENTIFYING A SW
TO NE GRADIENT OF MOISTURE ACROSS THE FCST AREA ON SATURDAY THAT
REPRESENTS WHAT IS LEFT OF THE FRONT. THAT SHOULD LEAD TO SOME
IDENTIFIABLE DIFFERENCES IN THE WEATHER BETWEEN NE GEORGIA AND
WESTERN SC...WHICH SHOULD HAVE ANOTHER DAY MUCH LIKE TODAY...TO THE
WESTERN PIEDMONT OF NC WHICH SHOULD HAVE A STRONGER NE WIND
ADVECTING COOLER AND DRIER AIR THAT WILL GREATLY INHIBIT CONVECTION
AND KEEP TEMPS BELOW NORMAL.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AT 230 PM EDT FRIDAY...ON SATURDAY EVENING AN UPPER RIDGE WILL
EXTEND FROM GA AND THE CAROLINAS...TO THE GREAT LAKES...WHILE AN
UPPER LOW WILL BE OVER SE TX...AND A MUCH DEEPER UPPER LOW WILL BE
WELL OFF THE NEW ENGLAND COAST. THE UPPER RIDGE PROGRESSES VERY
SLOWLY TO THE EAST COAST BY MONDAY...WHILE THE UPPER LOW OVER TX
FILLS...AND THE ATLANTIC UPPER LOW REMAINS NEARLY STATIONARY.
A SLOW MOVING COLD FRONT WILL MOVE ACROSS THE SAVANNAH RIVER VALLEY
SATURDAY NIGHT...WITH SUBSTANTIAL MOISTURE BEHIND IT. AN EASTERLY
LOW LEVEL FLOW COMPONENT IN THE WAKE OF THE FRONT WILL KEEP MOIST
UPSLOPE LIFT OVER THE SOUTHERN BLUE RIDGE...SUPPORTING CONTINUING
PRECIPITATION THERE....WHILE LINGERING INSTABILITY ALONG THE
BOUNDARY ITSELF SUPPORTS PRECIPIATION IN THE SAVANNAH RIVER VALLEY.
THE FRONT MOVES FARTHER INTO GA ON SUNDAY...HIGH PRESSURE ALONG THE
EASTERN SEABOARD WILL PUSH DRIER AIR SOUTHWEST INTO THE PIEDMONT OF
THE CAROLINAS. LINGERING MOISTURE WILL STILL SUPPORT CLOUD COVER AND
PRECIPITATION IN THE SAVANNAH RIVER VALLEY AND OVER THE MUCH OF THE
MOUNTAINS...THOUGH INSTABILITY WILL BE MUCH LESS WITH COOLER SURFACE
AIR MOVING IN.
MOISTURE STARTS TO SPREAD EAST AGAIN ON SUNDAY NIGHT AND MONDAY AS
SURFACE HIGH PRESSURE MOVES FROM THE EASTERN SEABOARD TO OFF THE
CAROLINA COAST...ALLOWING WARM MOIST ADVECTION FORM THE GULF TO
REACH NE GA AND THE WESTERN CAROLINAS. POPS WILL BE ALLOWED TO
SPREAD EAST AS A RESULT...AND INCREASING INSTABILITY WILL BE MORE
SUPPORTIVE OF CONVECTION ON MONDAY.
TEMPERATURES WILL TREND DOWNWARD AS THE COOLER AIR MASS SETTLE
IN...UNTIL MONDAY...WHEN WARM ADVECTION ENSUES IN SOUTHERLY FLOW ON
THE BACK SIDE OF THE DEPARTING HIGH PRESSURE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AT 230 PM EDT FRIDAY...THE EXTENDED FORECAST WILL FEATURE A
DEAMPLIFIED PATTERN...WITH A FLAT UPPER RIDGE OVER THE SOUTHEAST...
AND MOORE OR LESS ZONAL FLOW TO THE NORTH. WEAK HIGH PRESSURE WILL
BE CENTERED OFF THE CAROLINA COAST ON TUESDAY...WHILE THE REMNANTS
OF A COLD FRONT CROSS THE APPALACHIANS FROM THE WEST. RESIDUAL
MOISTURE ASSOCIATED WITH A FRONTOLYTIC ZONE OVER THE SOUTHERN
APPALACHIANS WILL SUPPORT PRECIPITATION LONG BEFORE THE FRONT
ARRIVES. THE SLOW MOVING BOUNDARY LEAVES THE AREA BY EARLY
WEDNESDAY...HOWEVER DRYING BEHIND IT IS SOMEWHAT LIMITED...AND MODEL
SOUNDINGS SHOW INSTABILITY AND LOW LEVEL MOISTER PERSISTING IN
SUBSEQUENT DAYS. TEMPERATURES WILL RUN NEAR MID SUMMER NORMALS.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...CEILING SLOW TO LIFT OUT OF MVFR RANGE EARLY THIS
AFTERNOON...AND IT LOOKS AS IF THE MVFR CEILING WILL PREVAIL UNTIL
21Z OR SO WHEN HEATING WILL EITHER LIFT IT TO VFR OR CONVECTION WILL
SCATTER IT OUT. DEEP CONVECTION WILL FIRE ACROSS THE PIEDMONT INTO
THE AFTERNOON...BUT MOST LIKELY NEAR KCLT IN A WINDOW FROM 21Z TO
01Z BASED MOSTLY ON THE HRRR AND WRF-ARW. STORMS COULD LINGER BEYOND
THAT BUT WILL BE LEFT OUT FOR NOW. WIND IS EXPECTED TO REMAIN S OR
SE INTO THE EVENING AWAY FROM THUNDERSTORM OUTFLOW BOUNDARIES. LATER
TONIGHT...SIMILAR TO LAST NIGHT...A WEAK UPSLOPE FLOW INTO THE
PIEDMONT SHOULD FORCE EITHER A LOW CLOUD CEILING OR LIGHT FOG. WENT
WITH A STRATUS DECK IN THE LOW END OF THE MVFR RANGE ALTHO IFR IS
NOT OUT OF THE QUESTION AROUND SUNRISE. THE CEILING WILL RISE
THROUGH THE MORNING AND SCATTER OUT BY MIDDAY. EXPECT A NE WIND ON
SATURDAY MORNING ONCE AGAIN.
ELSEWHERE...SCATTERED THUNDERSTORMS THROUGH THE EARLY EVENING WITH
TEMPORARY MVFR RESTRICTIONS. SIMILAR TO KCLT IN MOST REGARDS WITH
SLIGHT DIFFERENCES IN DETAIL. ANY PLACES WITH RAINFALL WILL BE
LIKELY TO GET A PERIOD OF FOG OVERNIGHT.
OUTLOOK...ALTHOUGH GRADUAL DRYING WILL DEVELOP FROM THE NE OVER THE
WEEKEND INTO EARLY NEXT WEEK...CONTINUED BOUNDARY LAYER MOISTURE
WILL PRODUCE ISOLATED TO SCATTERED DIURNAL CONVECTION EACH DAY...
WITH MORNING RESTRICTIONS POSSIBLE.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT MED 71% HIGH 100% HIGH 84% HIGH 88%
KGSP MED 70% HIGH 100% HIGH 85% MED 75%
KAVL HIGH 91% HIGH 97% HIGH 87% HIGH 83%
KHKY MED 66% HIGH 91% HIGH 88% HIGH 88%
KGMU MED 79% HIGH 100% HIGH 89% HIGH 80%
KAND HIGH 100% HIGH 100% MED 75% MED 73%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JAT
NEAR TERM...PM
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...PM
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
203 PM EDT FRI MAY 30 2014
.SYNOPSIS...
A BACKDOOR COLD FRONT WILL SLOWLY CROSS THE FORECAST AREA FROM THE
NORTHEAST THROUGH SATURDAY NIGHT. HIGH PRESSURE WILL BUILD IN FROM
THE NORTHEAST LATE IN THE WEEKEND. THIS HIGH PRESSURE MOVE OFFSHORE
BY MIDWEEK...WHILE MOISTURE INCREASES OVER OUR AREA FROM THE WEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF EARLY AFTERNOON...PLENTY OF DEEP CONVECTION FIRING ALONG AND
NEAR THE BLUE RIDGE...WHILE CONVECTIVE INITIATION WAS UNDERWAY
ELSEWHERE OVER THE PIEDMONT. COVERAGE SHOULD CONTINUE TO INCREASE
THROUGH THE AFTERNOON. STILL EXPECTING A FEW SEVERE THUNDERSTORMS...
ALTHO POTENTIAL NOT AS GREAT AS YESTERDAY...AND SLOW MOVING STORMS
SUGGEST ANOTHER FLASH FLOOD THREAT. TEMPS LOOK OKAY.
REMAINDER OF PREVIOUS DISCUSSION...
BACK DOOR COLD FRONT ISN/T MUCH OF A COLD FRONT. LATEST SURFACE
ANALYSIS DEPICTS ONLY A VERY GRADUAL GRADIENT IN TEMP AND DEWPOINT
ACROSS THE SOUTHEAST/MID-ATLANTIC...WITH LOWER 60S DEWPOINTS FOUND
AS FAR NORTH AS CENTRAL VIRGINIA. YESTERDAY/S RELATIVELY STRONG
TEMP GRADIENT BETWEEN WESTERN AND CENTRAL NC APPEARED TO HAVE MORE
TO DO WITH A CLOUD COVER GRADIENT THAN BONAFIDE BAROCLINITY. IN
FACT...THERE ISN/T EVEN MUCH OF A DISCERNIBLE WIND SHIFT ZONE ACROSS
THE REGION ATTM. ALL THIS IS TO SAY THAT IT IS UNCERTAIN HOW MUCH OF
A ROLE THE BOUNDARY WILL HAVE IN FOCUSING CONVECTION ACROSS THE AREA
THIS AFTERNOON. THE MESOSCALE MODELS SEEM TO BE HIGHLIGHTING TYPICAL
DIFFERENTIAL HEATING EFFECTS AS THE PRIMARY DRIVER OF INITIATION
THIS AFTERNOON. STEERING CURRENTS AND COLD POOL PROPAGATION
MECHANISMS WOULD FAVOR SOUTHEAST MOVEMENT OF CONVECTION ORIGINATING
OVER THE HIGH TERRAIN THIS AFTERNOON INTO THAT PART OF THE PIEDMONT
ROUGHLY SOUTH OF I-40 AND EAST OF THE UPPER SAVANNAH RIVER VALLEY.
THIS ALSO HAPPENS TO BE WHERE SOME MODEL GUIDANCE IS FOCUSING A
BROAD AREA OF BOUNDARY LAYER CONVERGENCE ALONG THE SURFACE BOUNDARY.
IT IS CERTAINLY POSSIBLE THAT THE BOUNDARY WILL BECOME BETTER
DEFINED LATER TODAY...IF CLOUD COVER TO THE NORTH LINGERS LONG
ENOUGH TO HOLD DOWN TEMPS/STRENGTHEN THE THERMAL GRADIENT. ALL
THINGS CONSIDERED...LIKELY POPS APPEAR WARRANTED FROM THESE AREAS
WEST TO THE HIGH TERRAIN ALONG THE BLUE RIDGE.
SLIGHTLY COOLER THICKNESSES AND MORE EXTENSIVE CLOUD COVER SHOULD
SUPPORT MAXES ABOUT A CATEGORY COOLER THAN THURSDAY. THIS WILL ALSO
ACT TO LIMIT INSTABILITY SOMEWHAT...SO THE THREAT FOR SEVERE WEATHER
WILL CONTINUE TO BE LIMITED TO A HANDFUL OF MARGINAL PULSE SEVERE
STORMS IN THE MODERATELY UNSTABLE (BUT MOIST) AND VERY WEAKLY
SHEARED ENVIRONMENT. RELATIVELY SLOW CELL MOVEMENT...AND THE
POTENTIAL FOR TRAINING (ASSUMING THE BOUNDARY BECOMES BETTER
DEFINED) WILL YIELD A THREAT FOR FLASH FLOODING...BUT THE THREAT
CONTINUES TO BE APPEAR TOO LOCALIZED TO ENTERTAIN THOUGHTS OF A
FLASH FLOOD WATCH ATTM.
CONVECTION WILL AGAIN LINGER INTO THE EVENING IN THE MOIST AIR MASS.
THE EXCEPTION WILL BE ACROSS THE NORTHERN ZONES...WHERE DRIER AIR
WILL FINALLY BEGIN FILTERING IN. ACROSS THE REMAINDER OF THE
AREA...THE WEAKLY FORCED/WEAKLY SHEARED ENVIRONMENT SHOULD NOT
SUPPORT ACTIVITY FOR TOO LONG AFTER MIDNIGHT. MIN TEMPS WILL
GENERALLY BE A CATEGORY OR SO ABOVE CLIMO.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AT 330 AM EDT FRIDAY...THE SHORT TERM PERIOD INITIALIZES SATURDAY
MORNING WITH A BACK DOOR COLD FRONT CONTINUING TO SLIDE SOUTH
ALLOWING FOR NORTHERLY FLOW TO PREVAIL. A DRIER AND MORE STABLE
AIRMASS WILL ADVECT IN THROUGH THE MORNING AND AFTERNOON HOURS AS
HIGH PRESSURE SLIDES SOUTHEAST. HOWEVER...THE SLOW PROGRESSION OF
THIS ADVECTION WILL LIKELY LEAVE A BAND OF UNSTABLE AIR IN THE
VICINITY OF INTERSTATE 85 SOUTHWARD INTO THE MIDLANDS...LEADING TO
INCREASED SHOWER AND THUNDERSTORM POTENTIAL. THUS...WILL HIGHLIGHT
SLIGHT CHANCE POPS ACROSS MUCH OF THE NC/SC PIEDMONTS INCREASING TO
SOLID CHANCE LEVEL POPS FURTHER SOUTHWEST ADJACENT TO MOISTURE
AXIS.
FOR SUNDAY...HIGH PRESSURE WILL SLOWLY SLIDE SOUTHEAST ACROSS THE
MID ATLANTIC COAST YIELDING INITIAL NORTHERLY FLOW THAT WILL VEER
SOUTHEASTERLY THROUGH THE END OF THE PERIOD. THIS INCREASING
SURFACE HIGH PRESSURE ALONG WITH UPPER LEVEL RIDGING WILL LEAD TO A
DRY FORECAST THROUGH THE DAY ON SUNDAY ACROSS THE PIEDMONT REGIONS
WITH SLIGHT CHANCE POPS HIGHLIGHTED ACROSS PORTIONS OF THE WESTERN
UPSTATE AND THE HIGH TERRAIN OF WESTERN NC AND NORTHEAST GA AS WEAK
EASTERLY UPSLOPE FLOW COULD PROVIDE ENOUGH LIFT FOR A FEW SHOWERS
AND OR THUNDERSTORMS. THESE POPS WILL TAPER DOWN THROUGH THE
AFTERNOON AS THE SURFACE RIDGE SETTLES OVER THE SANDHILLS AND
COASTAL PLAIN OF NC LEADING TO A DRY FORECAST THROUGH MONDAY
MORNING. TEMPERATURES THROUGH THE SHORT TERM PERIOD WILL GRADUALLY
COOL WITH BELOW NORMAL TEMPERATURES EXPECTED BY SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AT 345 AM EDT FRIDAY...THE EXTENDED RANGE PERIOD WILL INITIALIZE
MONDAY MORNING UNDER DEEP LAYER RIDGING. A SURFACE HIGH CENTERED OF
THE NC/SC COASTLINE WILL SLOWLY SLIDE SOUTHEASTWARD THROUGH MONDAY
INTO TUESDAY BEFORE ESTABLISHING ITSELF AS A BERMUDA HIGH BY
MIDWEEK. MEANWHILE...SURFACE CYCLOGENESIS WILL BE OCCURRING ACROSS
THE UPPER MIDWEST AS A WEAK UPPER WAVE EJECTS THROUGH THE MEAN FLOW
ALOFT. THIS LOW PRESSURE SYSTEM WILL PUSH THROUGH THE GREAT LAKES
AND INTO SOUTHERN ONTARIO THROUGH MIDWEEK WITH A WEAK COLD FRONT
SLIDING SOUTHWARD INTO THE OHIO VALLEY...EVENTUALLY STALLING OUT TO
OUR NORTH. THIS OVERALL PATTERN WILL YIELD INCREASINGLY UNSETTLED
WEATHER ACROSS THE SOUTHERN APPALACHIANS AS SOUTHERLY FLOW RAMPS UP
ALLOWING FOR ATLANTIC...AND EVENTUALLY GULF MOISTURE TO ADVECT IN.
AS THE PRESSURE GRADIENT INCREASES THROUGH MIDWEEK...THIS ADVECTION
WILL ALSO MAGNIFY LEADING TO INCREASED POTENTIAL FOR MOSTLY DIURNAL
SHOWERS AND THUNDERSTORMS EACH AFTERNOON. THUS...FORECAST
HIGHLIGHTS CHANCE LEVELS POPS ACROSS THE MOUNTAINS ON MONDAY BEFORE
SPREADING EASTWARD ACROSS THE ENTIRE CWFA BY WEDNESDAY...LASTING
THROUGH THE PERIOD ON A DIURNAL TREND. FORECAST SOUNDINGS INDICATE
WEAK FLOW ALOFT ALONG WITH PWAT VALUES TOPPING 1.5 INCHES...THUS
THERE COULD BE POTENTIAL FOR FLOODING ALONG WITH OTHER CONVECTIVE
THREATS. TEMPERATURES THROUGH THE EXTENDED RANGE PERIOD WILL
MODERATE AMIDST THE INCREASING WAA LEADING TO ABOVE NORMAL
TEMPERATURES EACH DAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...CEILING SLOW TO LIFT OUT OF MVFR RANGE EARLY THIS
AFTERNOON...AND IT LOOKS AS IF THE MVFR CEILING WILL PREVAIL UNTIL
21Z OR SO WHEN HEATING WILL EITHER LIFT IT TO VFR OR CONVECTION WILL
SCATTER IT OUT. DEEP CONVECTION WILL FIRE ACROSS THE PIEDMONT INTO
THE AFTERNOON...BUT MOST LIKELY NEAR KCLT IN A WINDOW FROM 21Z TO
01Z BASED MOSTLY ON THE HRRR AND WRF-ARW. STORMS COULD LINGER BEYOND
THAT BUT WILL BE LEFT OUT FOR NOW. WIND IS EXPECTED TO REMAIN S OR
SE INTO THE EVENING AWAY FROM THUNDERSTORM OUTFLOW BOUNDARIES. LATER
TONIGHT...SIMILAR TO LAST NIGHT...A WEAK UPSLOPE FLOW INTO THE
PIEDMONT SHOULD FORCE EITHER A LOW CLOUD CEILING OR LIGHT FOG. WENT
WITH A STRATUS DECK IN THE LOW END OF THE MVFR RANGE ALTHO IFR IS
NOT OUT OF THE QUESTION AROUND SUNRISE. THE CEILING WILL RISE
THROUGH THE MORNING AND SCATTER OUT BY MIDDAY. EXPECT A NE WIND ON
SATURDAY MORNING ONCE AGAIN.
ELSEWHERE...SCATTERED THUNDERSTORMS THROUGH THE EARLY EVENING WITH
TEMPORARY MVFR RESTRICTIONS. SIMILAR TO KCLT IN MOST REGARDS WITH
SLIGHT DIFFERENCES IN DETAIL. ANY PLACES WITH RAINFALL WILL BE
LIKELY TO GET A PERIOD OF FOG OVERNIGHT.
OUTLOOK...ALTHOUGH GRADUAL DRYING WILL DEVELOP FROM THE NE OVER THE
WEEKEND INTO EARLY NEXT WEEK...CONTINUED BOUNDARY LAYER MOISTURE
WILL PRODUCE ISOLATED TO SCATTERED DIURNAL CONVECTION EACH DAY...
WITH MORNING RESTRICTIONS POSSIBLE.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT MED 71% HIGH 100% HIGH 84% HIGH 88%
KGSP MED 70% HIGH 100% HIGH 85% MED 75%
KAVL HIGH 91% HIGH 97% HIGH 87% HIGH 83%
KHKY MED 66% HIGH 91% HIGH 88% HIGH 88%
KGMU MED 79% HIGH 100% HIGH 89% HIGH 80%
KAND HIGH 100% HIGH 100% MED 75% MED 73%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JAT
NEAR TERM...PM
SHORT TERM...CDG
LONG TERM...CDG
AVIATION...PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
404 PM EDT FRI MAY 30 2014
.SYNOPSIS...
A BACKDOOR COLD FRONT WILL CONTINUE TO PUSH SOUTHWESTWARD
TONIGHT...MOVING SOUTH OF THE FORECAST AREA BY SATURDAY.
COOLER...MORE STABLE MARITIME AIR BEHIND THE FRONT WILL RESULT IN
LESS SHOWER AND THUNDERSTORMS INTO THE WEEKEND AS HIGH PRESSURE
BUILDS OVER THE REGION. HIGH PRESSURE ALOFT WILL BUILD INTO THE
REGION NEXT WEEK BRINGING WARMER AND MORE HUMID CONDITIONS BACK TO
THE REGION ALONG WITH INCREASING CHANCES FOR AFTERNOON SHOWERS AND
THUNDERSTORMS.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 330 PM EDT FRIDAY...
DIFFUSE BACKDOOR COLD FRONT STRETCHES ACROSS SOUTHWESTERN PORTIONS OF
THE FORECAST AREA THIS AFTERNOON. CONVECTION DEVELOPING IN THE MOIST
UNSTABLE AIR INVOF THE SURFACE BOUNDARY AND TRAVEL SOUTHEAST ALONG
THE SOUTHERN EDGE OF WEAK NORTHWEST FLOW ALOFT. SFC BASED CAPES THIS
AFTERNOON HAVE CLIMB TO 1000 TO 2000 J/KG WITH LIS AROUND MINUS 4
ACROSS SOUTHWEST CORNER OF CWA THIS AFTERNOON. HOWEVER...WEAK
VERTICAL SHEAR WILL LIMIT STORM ORGANIZATION AND LIFE SPAN THIS
AFTERNOON INTO THIS EVENING...LOCALLY HEAVY RAINS...GUSTY WINDS AND
HAIL ARE POSSIBLE WITH THE STRONGEST THUNDERSTORMS DURING THE NEXT
COUPLE OF HOURS.
IN SHARP CONTRAST...MARINE AMS IN THE EASTERN PORTION OF THE
FORECAST AREA HAS BEEN VERY SLOW TO ERODE AND HOLDING TEMPERATURES
DOWN. HARD TO TELL HOW MUCH SUN ANGLE AND MIXING WILL BREAK UP THE
LOW CLOUDS THIS EVENING INTO TONIGHT. SATELLITE TRENDS SHOWED THAT
WEST EDGE OF CLOUDS BREAKING UP BEFORE SUNSET.
DECIDED TO PLAY POPS TONIGHT CLOSE TO A BLEND OF HRRR AND NAM WITH
HIGHEST CHANCES IN SOUTHWEST BASICALLY WEST OF I77. LOW CLOUDS AND
FOG WILL REDEVELOP OVERNIGHT. WENT WITH LOW TEMPERATURES TONIGHT
CLOSE TO THE ADJMETBC WITH READINGS FROM THE MID 50S IN THE COOLER
MOUNTAIN VALLEYS TO THE LOWER 60S IN THE SOUTHEAST.
WITH BOUNDARY ACROSS NORTH CAROLINA AND SOUTHEAST UPSLOPE
FLOW...KEPT ISOLATED SCATTERED POPS FOR CONVECTION ACROSS
SOUTHWEST CORNER OF CWA. THE SWODY2 HAS PUSHED MENTION OF
THUNDERSTORMS SOUTH OF OUR FORECAST AREA FOR SATURDAY. MORNING LOW
CLOUDS AND FOG SHOULD MIX OUT OR LIFT BY LATE SATURDAY MORNING.
HIGH TEMPERATURES SATURDAY ARE A CHALLENGE WITH EASTERLY FLOW AND
CLOUD COVER. RAISED HIGHS UP SATURDAY AFTERNOON WITH READINGS FROM
THE MID 70S IN THE MOUNTAINS TO THE LOWER 80S ALONG THE SOUTHERN
BLUE RIDGE MOUNTAINS.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 330 PM EDT FRIDAY...
DIFFUSE FRONT WASHES OUT OVER THE SOUTHERN APPALACHIANS AS SURFACE
HIGH PRESSURE SINKS SOUTH ACROSS THE DELMARVA SUNDAY. THE SURFACE
HIGH THEN BECOMES POSITIONED JUST OFF THE CAROLINA COAST MONDAY.
EXPECTING A DRY FINISH TO THE WEEKEND ALONG WITH NEAR TO SLIGHTLY
BELOW NORMAL TEMPERATURES...FOLLOWED BY A TRANSITON TO WARMER
TEMPERATURES AND A THREAT OF AFTERNOON SHOWERS BEGINNING MONDAY.
FOR SATURDAY NIGHT AND SUNDAY OR UNTIL THE HIGH BECOMES SITUATED
OFF THE SOUTHEAST ATLANTIC COAST...SURFACE WINDS WILL REMAIN FROM
THE EAST. THIS WILL PROMOTE SHALLOW UPSLOPE CLOUDINESS ALONG AND
EAST OF THE APPALACHIAN DIVIDE...BKN SORT OF CONDITIONS SATURDAY
NIGHT AND SCATTERED SUNDAY. BY MONDAY TENDENCY WILL BE FOR
MODERATE CU FORMATION OVER THE MOUNTAINS AS RETURN SOUTHWESTERLY
FLOW BRINGS INCREASING DEWPOINTS AND HIGHER CAPE.
H85 TEMPS OF 8C IN THE VA PIEDMONT ON SUNDAY WILL REBOUND CLOSER
TO 15C ON MONDAY. SUNDAY DEFINITELY LOOKS LIKE A WINNER IN TERMS
OF COMFORT FOR THE FIRST DAY OF JUNE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 PM EDT FRIDAY...
THE UPPER FLOW PATTERN NEXT WEEK WILL FEATURE A PERSISTENT UPPER
RIDGE CENTERED OVER NORTHERN MEXICO...EXTENDING EAST ACROSS THE
SOUTHERN CONUS...INCLUDING THE SOUTHEAST STATES. NORTH OF THIS
RIDGE...A MORE ZONAL TYPE PATTERN WILL EXISTS ACROSS THE CENTRAL
AND NORTHERN CONUS...ALTHOUGH VERY NOISY...WITH EMBEDDED SHORT
WAVE ENERGY RIPPLING EAST WITHIN THE FASTER WESTERLY WINDS ALOFT.
WITH THE EXTENSION OF THE UPPER RIDGE COVERING THE SOUTHEAST STATES
WINDS SURFACE AND ALOFT WILL BE OUT OF THE WEST OR SOUTHWEST. THIS
WILL FAVOR A MORE SUMMER LIKE PATTERN WITH TEMPERATURES CLIMBING
ABOVE NORMAL...MODEL GUIDANCE SUGGESTING READINGS ABOUT 10 DEGREES
ABOVE THE NORM FOR DAYTIME HIGHS AND AT LEAST 5 DEGREES ABOVE THE
NORM FOR OVERNIGHT LOWS.
THE PATTERN ALSO SUGGESTS THE FORECAST AREA WILL BE SUBJECT TO A
DAILY THREAT OF SHOWERS AND THUNDERSTORMS...NOTHING ORGANIZED PER SE
OR LASTING FOR ANY SIGNIFICANT LENGTH OF TIME...BUT MAINLY SCATTERED
IN NATURE. IF THERE IS ANYTHING CLOSE TO BEING ORGANIZED IT WILL
MOST LIKELY COME FROM SOMETHING GENERATED OVER THE OHIO VALLEY
ASSOCIATED WITH ONE OF THE SHORTWAVE DISTURBANCES ALOFT...THIS
ACTIVITY POTENTIALLY MOVING DOWNSTREAM INTO OUR FORECAST AREA IN
THE FORM OF THUNDERSTORM CLUSTERS OR A SQUALL LINE. OUTSIDE OF
THIS UPSTREAM THREAT...LOCAL THUNDERSTORM DEVELOPMENT WILL BE THE
TYPICAL DIURNALLY DRIVEN DEEP CONVECTION...WITH BEST CHANCES IN
THE MOUNTAINS ESPECIALLY ALONG THE BLUE RIDGE WHERE WIND
CONVERGENCE WILL BE THE GREATEST. WITH WESTERLY SORT OF WINDS
ALOFT...A LEE TROUGH WILL LIKELY EXIST OVER THE PIEDMONT WHICH
WILL AID IN SCATTERED LATE AFTERNOON STORM DEVELOPMENT THERE TOO.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
AS OF 153 PM EDT FRIDAY...
DIFFUSE BACKDOOR FRONT REMAINS ACROSS THE WESTERN PART OF THE CWA
THIS AFTERNOON. THIS BOUNDARY EXPECTED TO MOVE SOUTHWARD TONIGHT
INTO SATURDAY. AT 1739Z KFCX 88D SHOWED ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS MOVING SOUTH THIS AFTERNOON. CONVECTION
EXPECTED TO FORM MAINLY WEST OF I77 THIS AFTERNOON INTO THIS
EVENING IN THE UNSTABLE AIR.
IN THE EAST...MOIST EASTERLY MARITIME FLOW KEEPING IFR CIGS
FROM LYH TO SOUTH BOSTON EAST. WHILE IN THE WEST...SCT TO BKN
MVFR CLOUDS AT TAF SITES.
DIURNAL CONVECTION...MAINLY WEST OF A BLF-SIF LINE WILL DISSIPATE
QUICKLY AROUND SUNSET. AREAS OF FOG/LOW CLOUDS WILL ONCE DEVELOP
TONIGHT. A FEW LOCATIONS WILL DROP TO IFR/LIFR IN DENSE
FOG...SUCH AS LWB. VSBYS SHOULD IMPROVE TO MVFR OR BETTER AFT
15Z...BUT WITH E-NE FLOW EXPECT POCKETS OF HZ EAST OF THE BLUE
RIDGE. LOWER CLOUDS WILL LIFT TO SCT-BKN MVFR/VFR SATURDAY.
WINDS...NE-ESE AT SPEEDS OF 5-7KTS THIS AFTERNOON WILL BECOME
LIGHT AND VARIABLE OVERNIGHT.
MEDIUM CONFIDENCE IN CIGS AND VSBYS THROUGH THE TAF VALID PERIOD.
MEDIUM TO HIGH CONFIDENCE IN WIND DIR/SPD THROUGH THE TAF VALID
PERIOD.
EXTENDED AVIATION DISCUSSION...
VFR CONDITIONS WILL PREVAIL FOR THE WEEKEND...EXCEPT FOR BRIEFLY
OVERNIGHT IN MOUNTAIN VALLEYS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...KK
NEAR TERM...KK
SHORT TERM...PM
LONG TERM...PM
AVIATION...KK/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
153 PM EDT FRI MAY 30 2014
.SYNOPSIS...
A BACKDOOR COLD FRONT LOCATED ACROSS SOUTHWEST VIRGINIA AND
NORTHWEST NORTH CAROLINA WILL CONTINUE TO PUSH SOUTHWESTWARD
TODAY...MOVING SOUTH OF THE FORECAST AREA BY SATURDAY.
COOLER...MORE STABLE MARITIME AIR BEHIND THE FRONT WILL RESULT IN
LESS SHOWER AND THUNDERSTORMS INTO THE WEEKEND AS HIGH PRESSURE
BUILDS OVER THE REGION. HIGH PRESSURE ALOFT WILL BUILD INTO THE
REGION NEXT WEEK BRINGING WARMER AND MORE HUMID CONDITIONS BACK TO
THE REGION ALONG WITH INCREASING CHANCES FOR AFTERNOON SHOWERS AND
THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1215 PM EDT FRIDAY...
DECREASED CLOUD COVER ACROSS WESTERN HALF OF FORECAST AREA.
RAISED TEMPERATURES AND HIGH TEMPERATURES THIS AFTERNOON FOR LESS
CLOUDS.
AS OF 925 AM EDT FRIDAY...
BACKDOOR COLD FRONT THIS MORNING ACROSS WESTERN PORTIONS OF
FORECAST AREA. THIS BOUNDARY WILL CONTINUE TO PUSH SOUTHWEST
TODAY. EASTERLY WINDS PUSHING MOISTURE UP MOUNTAINS WITH LOW
CLOUDS AND FOG IN EASTERN PORTIONS OF REGION. SATELLITE LOOP
SHOWED MIXING HAS THIN OUT CLOUD COVER IN THE WEST...WHILE LOW
CLOUDS HOLDING IN THE EAST. DECREASED CLOUD COVER ON THE WESTERN
PORTION OF FORECAST AREA TO MATCH UP BETTER WITH SFC OBS AND
SATELLITE TRENDS. HRRR AND RNK WRFARW INDICATED SCATTERED
CONVECTION POSSIBLE MAINLY WEST OF I77 THIS AFTERNOON. THE SWODY1
HIGHLIGHTED THE CHANCE OF THUNDER ACROSS SOUTHWEST PORTION OF
FORECAST AREA. HIGH TEMPERATURES ARE TRICKY THIS AFTERNOON
DEPENDING ON CLOUD COVER AND CONVECTION. WITH CAUTION WILL HOLD
WITH CURRENT HIGHS AND WATCH TRENDS FOR THIS MORNING FOR
MODIFICATIONS.
AS OF 445 AM EDT FRIDAY...
DIFFUSE BACKDOOR COLD FRONT NEAR A BLF-SIF LINE. COOLER...MARITIME
LIGHT EASTERLY FLOW COMBINED WITH WET GROUND FROM LATE DAY
RAINFALL THU HAS RESULTED IN WIDESPREAD LOW CLOUDS/CIGS EARLY THIS
MORNING...ALONG WITH AREAS OF FOG. SO FAR...THE STRATUS HAS BEEN
MORE SIGNIFICANT THAN THE FOG. MODELS IN GENERAL AGREEMENT THAT
THE BACKDOOR FRONT WILL CONTINUE TO SAG SOUTHWESTWARD THROUGH THE
DAY...AND SHOULD BE SW OF THE FORECAST AREA BY EARLY SAT. THIS
WILL RESULT IN TWO WEATHER CHANGES ACROSS THE REGION TODAY AS
COMPARED TO THU. SHRA/TSRA WILL BE CONFINED TO FAR SW VA/NW
NC...WHERE THE AIR MASS WILL REMAIN UNSTABLE/WARM ENOUGH TO
SUPPORT AFTERNOON SHRA/TSRA...AND LOW CLOUDS WILL LIKELY REMAIN IN
PLACE...ESPECIALLY IN UPSLOPE AREAS EAST OF THE ALLEGHANYS/BLUE
RIDGE THROUGHOUT THE DAY AND INTO THE EVENING. SPOTTY -DZ MAY
OCCUR IN AREAS ALONG THE BLUE RIDGE...BUT MOSTLY IT WILL JUST BE
CLOUDS.
THE BIG CHALLENGE FOR TODAY...BROUGHT ON BY THE CLOUDS AND COOL
EASTERLY FLOW...WILL BE THE MAX TEMPERATURES.
GUIDANCE...ESPECIALLY THE GFS MOS APPEARS WAY TOO WARM. THE AIR
MASS UPSTREAM IS QUITE COOL FOR LATE MAY WITH TEMPS EARLY THIS
MORNING NEAR 50 ACROSS NORTHERN VA. FRANKLY...PERSISTENCE FOR
TEMPS IN WEDGE AREAS MIGHT BE THE BEST WAY TO GO TODAY...BUT HAVE
USED A BLEND OF THE COLDER MODELS...NAMELY MET MOS AND ECMWF
MOS...COMBINED WITH PERSISTENCE AND EXPECTATION THAT CLOUDS WILL
BE VERY SLOW/TOUGH TO ERODE TODAY EAST OF THE ALLEGHANY FRONT.
THIS WILL RESULT IN MAX T GENERALLY 5-7 DEGREES BELOW NORMAL AND
GOING 1-2 CATEGORIES COLDER THAN MOST MOS GUIDANCE. MIN T TONIGHT
LESS OF AN ISSUE AS CLOUDS AND LITTLE T/TD SPREAD WILL RESULT IN
RELATIVELY MILD MIN TEMPERATURES DESPITE THE WEDGE. THE EXCEPTION
WOULD BE IF DRIER AIR ADVECTING SWWD FROM THE MID-ATLANTIC REACHES
THE PIEDMONT...BUT CURRENT THINKING IS THAT THIS WILL NOT HAPPEN
QUICKLY ENOUGH TO RESULT IN ANY SUBSTANTIAL EFFECT TO MIN T SAT
MORNING.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM EDT FRIDAY...
WITH SURFACE HIGH PRESSURE EVENTUALLY SINKING SOUTH INTO THE
DELMARVA BY SUNDAY AFTERNOON...EXPECTING A DRY AND POSSIBLY
SLIGHTLY BELOW NORMAL WEEKEND. THIS HIGH WILL THEN DROP DOWN THE
EAST COAST AS THE UPPER TROUGH OVER NEW ENGLAND MOVES OUT TO
SEA...AND UPPER RIDGING TAKES HOLD THROUGH THE ENTIRE EASTERN US.
LOW CLOUDS AND FOG WILL DEVELOP OVERNIGHT WHILE THE WEDGE REMAINS
THIS WEEKEND...THEN BURN OFF DURING THE LATE MORNING AND
AFTERNOON. WINDS FINALLY VEER TO THE SW BY MONDAY...DELIVERING
MORE INSTABILITY AND A CHANCE FOR SHOWERS AND THUNDERSTORMS
THROUGH SE WEST VIRGINIA BY LATE DAY. H85 TEMPS MAY FALL TO 8C IN
THE VA PIEDMONT ON SUNDAY...BUT RAPID WAA ON SW WINDS MONDAY WILL
PUSH H85 TEMPS BACK TO 15C ON MONDAY.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 245 PM EDT THURSDAY...
THE UPPER FLOW PATTERN NEXT WEEK FEATURES A PERSISTENT UPPER RIDGE
CENTERED OVER NORTHERN MEXICO...EXTENDING EAST ACROSS THE SOUTHERN
CONUS...INCLUDING THE SOUTHEAST STATES. NORTH OF THIS RIDGE...A
MORE ZONAL TYPE PATTERN WILL EXISTS ACROSS THE CENTRAL AND NORTHERN
CONUS...ALTHOUGH VERY NOISY...WITH EMBEDDED SHORT WAVE ENERGY
RIPPLING EAST WITHIN THE FASTER WESTERLY WINDS ALOFT.
WITH THE EXTENSION OF THE UPPER RIDGE COVERING THE SOUTHEAST STATES
WINDS SURFACE AND ALOFT WILL BE OUT OF THE WEST OR SOUTHWEST. THIS
WILL FAVOR A MORE SUMMER LIKE PATTERN WITH TEMPERATURES CLIMBING
ABOVE NORMAL...MODEL GUIDANCE SUGGESTING READINGS ABOUT 10 DEGREES
ABOVE THE NORM FOR DAYTIME HIGHS AND AT LEAST 5 DEGREES ABOVE THE
NORM FOR OVERNIGHT LOWS.
THE PATTERN ALSO SUGGESTS THE FORECAST AREA WILL BE SUBJECT TO A
DAILY THREAT OF SHOWERS AND THUNDERSTORMS...NOTHING ORGANIZED PER SE
OR LASTING FOR ANY SIGNIFICANT LENGTH OF TIME...BUT MAINLY SCATTERED
IN NATURE. IF THERE IS ANYTHING CLOSE TO BEING ORGANIZED IF WILL
MOST LIKELY COME FROM SOMETHING GENERATED OVER THE OHIO VALLEY
ASSOCIATED WITH ONE OF THE SHORTWAVE DISTURBANCES ALOFT...THIS
ACTIVITY POTENTIALLY MOVING DOWNSTREAM INTO OUR FORECAST AREA IN THE
FORM OF THUNDERSTORM CLUSTERS OR A SQUALL LINE. OUTSIDE OF THIS
UPSTREAM THREAT...LOCAL THUNDERSTORM DEVELOPMENT WILL BE THE TYPICAL
DIURNALLY DRIVEN DEEP CONVECTION...WITH BEST CHANCES IN THE
MOUNTAINS ESPECIALLY ALONG THE BLUE RIDGE WHERE WIND CONVERGENCE
WILL BE THE GREATEST. IF THE WINDS ALOFT BECOME PURE WESTERLY...A
LEE TROUGH WILL FORM OVER THE PIEDMONT WHICH COULD AID IN SCATTERED
LATE AFTERNOON STORM DEVELOPMENT THERE TOO.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 153 PM EDT FRIDAY...
DIFFUSE BACKDOOR FRONT REMAINS ACROSS THE WESTERN PART OF THE CWA
THIS AFTERNOON. THIS BOUNDARY EXPECTED TO MOVE SOUTHWARD TONIGHT
INTO SATURDAY. AT 1739Z KFCX 88D SHOWED ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS MOVING SOUTH THIS AFTERNOON. CONVECTION
EXPECTED TO FORM MAINLY WEST OF I77 THIS AFTERNOON INTO THIS
EVENING IN THE UNSTABLE AIR.
IN THE EAST...MOIST EASTERLY MARITIME FLOW KEEPING IFR CIGS
FROM LYH TO SOUTH BOSTON EAST. WHILE IN THE WEST...SCT TO BKN
MVFR CLOUDS AT TAF SITES.
DIURNAL CONVECTION...MAINLY WEST OF A BLF-SIF LINE WILL DISSIPATE
QUICKLY AROUND SUNSET. AREAS OF FOG/LOW CLOUDS WILL ONCE DEVELOP
TONIGHT. A FEW LOCATIONS WILL DROP TO IFR/LIFR IN DENSE
FOG...SUCH AS LWB. VSBYS SHOULD IMPROVE TO MVFR OR BETTER AFT
15Z...BUT WITH E-NE FLOW EXPECT POCKETS OF HZ EAST OF THE BLUE
RIDGE. LOWER CLOUDS WILL LIFT TO SCT-BKN MVFR/VFR SATURDAY.
WINDS...NE-ESE AT SPEEDS OF 5-7KTS THIS AFTERNOON WILL BECOME
LIGHT AND VARIABLE OVERNIGHT.
MEDIUM CONFIDENCE IN CIGS AND VSBYS THROUGH THE TAF VALID PERIOD.
MEDIUM TO HIGH CONFIDENCE IN WIND DIR/SPD THROUGH THE TAF VALID
PERIOD.
EXTENDED AVIATION DISCUSSION...
VFR CONDITIONS WILL PREVAIL FOR THE WEEKEND...EXCEPT FOR BRIEFLY
OVERNIGHT IN MOUNTAIN VALLEYS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RAB
NEAR TERM...KK/RAB
SHORT TERM...KM
LONG TERM...PM
AVIATION...KK/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1217 PM EDT FRI MAY 30 2014
.SYNOPSIS...
A BACKDOOR COLD FRONT LOCATED ACROSS SOUTHWEST VIRGINIA AND
NORTHWEST NORTH CAROLINA WILL CONTINUE TO PUSH SOUTHWESTWARD
TODAY...MOVING SOUTH OF THE FORECAST AREA BY SATURDAY.
COOLER...MORE STABLE MARITIME AIR BEHIND THE FRONT WILL RESULT IN
LESS SHOWER AND THUNDERSTORMS INTO THE WEEKEND AS HIGH PRESSURE
BUILDS OVER THE REGION. HIGH PRESSURE ALOFT WILL BUILD INTO THE
REGION NEXT WEEK BRINGING WARMER AND MORE HUMID CONDITIONS BACK TO
THE REGION ALONG WITH INCREASING CHANCES FOR AFTERNOON SHOWERS AND
THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1215 PM EDT FRIDAY...
DECREASED CLOUD COVER ACROSS WESTERN HALF OF FORECAST AREA.
RAISED TEMPERATURES AND HIGH TEMPERATURES THIS AFTERNOON FOR LESS
CLOUDS.
AS OF 925 AM EDT FRIDAY...
BACKDOOR COLD FRONT THIS MORNING ACROSS WESTERN PORTIONS OF
FORECAST AREA. THIS BOUNDARY WILL CONTINUE TO PUSH SOUTHWEST
TODAY. EASTERLY WINDS PUSHING MOISTURE UP MOUNTAINS WITH LOW
CLOUDS AND FOG IN EASTERN PORTIONS OF REGION. SATELLITE LOOP
SHOWED MIXING HAS THIN OUT CLOUD COVER IN THE WEST...WHILE LOW
CLOUDS HOLDING IN THE EAST. DECREASED CLOUD COVER ON THE WESTERN
PORTION OF FORECAST AREA TO MATCH UP BETTER WITH SFC OBS AND
SATELLITE TRENDS. HRRR AND RNK WRFARW INDICATED SCATTERED
CONVECTION POSSIBLE MAINLY WEST OF I77 THIS AFTERNOON. THE SWODY1
HIGHLIGHTED THE CHANCE OF THUNDER ACROSS SOUTHWEST PORTION OF
FORECAST AREA. HIGH TEMPERATURES ARE TRICKY THIS AFTERNOON
DEPENDING ON CLOUD COVER AND CONVECTION. WITH CAUTION WILL HOLD
WITH CURRENT HIGHS AND WATCH TRENDS FOR THIS MORNING FOR
MODIFICATIONS.
AS OF 445 AM EDT FRIDAY...
DIFFUSE BACKDOOR COLD FRONT NEAR A BLF-SIF LINE. COOLER...MARITIME
LIGHT EASTERLY FLOW COMBINED WITH WET GROUND FROM LATE DAY
RAINFALL THU HAS RESULTED IN WIDESPREAD LOW CLOUDS/CIGS EARLY THIS
MORNING...ALONG WITH AREAS OF FOG. SO FAR...THE STRATUS HAS BEEN
MORE SIGNIFICANT THAN THE FOG. MODELS IN GENERAL AGREEMENT THAT
THE BACKDOOR FRONT WILL CONTINUE TO SAG SOUTHWESTWARD THROUGH THE
DAY...AND SHOULD BE SW OF THE FORECAST AREA BY EARLY SAT. THIS
WILL RESULT IN TWO WEATHER CHANGES ACROSS THE REGION TODAY AS
COMPARED TO THU. SHRA/TSRA WILL BE CONFINED TO FAR SW VA/NW
NC...WHERE THE AIR MASS WILL REMAIN UNSTABLE/WARM ENOUGH TO
SUPPORT AFTERNOON SHRA/TSRA...AND LOW CLOUDS WILL LIKELY REMAIN IN
PLACE...ESPECIALLY IN UPSLOPE AREAS EAST OF THE ALLEGHANYS/BLUE
RIDGE THROUGHOUT THE DAY AND INTO THE EVENING. SPOTTY -DZ MAY
OCCUR IN AREAS ALONG THE BLUE RIDGE...BUT MOSTLY IT WILL JUST BE
CLOUDS.
THE BIG CHALLENGE FOR TODAY...BROUGHT ON BY THE CLOUDS AND COOL
EASTERLY FLOW...WILL BE THE MAX TEMPERATURES.
GUIDANCE...ESPECIALLY THE GFS MOS APPEARS WAY TOO WARM. THE AIR
MASS UPSTREAM IS QUITE COOL FOR LATE MAY WITH TEMPS EARLY THIS
MORNING NEAR 50 ACROSS NORTHERN VA. FRANKLY...PERSISTENCE FOR
TEMPS IN WEDGE AREAS MIGHT BE THE BEST WAY TO GO TODAY...BUT HAVE
USED A BLEND OF THE COLDER MODELS...NAMELY MET MOS AND ECMWF
MOS...COMBINED WITH PERSISTENCE AND EXPECTATION THAT CLOUDS WILL
BE VERY SLOW/TOUGH TO ERODE TODAY EAST OF THE ALLEGHANY FRONT.
THIS WILL RESULT IN MAX T GENERALLY 5-7 DEGREES BELOW NORMAL AND
GOING 1-2 CATEGORIES COLDER THAN MOST MOS GUIDANCE. MIN T TONIGHT
LESS OF AN ISSUE AS CLOUDS AND LITTLE T/TD SPREAD WILL RESULT IN
RELATIVELY MILD MIN TEMPERATURES DESPITE THE WEDGE. THE EXCEPTION
WOULD BE IF DRIER AIR ADVECTING SWWD FROM THE MID-ATLANTIC REACHES
THE PIEDMONT...BUT CURRENT THINKING IS THAT THIS WILL NOT HAPPEN
QUICKLY ENOUGH TO RESULT IN ANY SUBSTANTIAL EFFECT TO MIN T SAT
MORNING.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM EDT FRIDAY...
WITH SURFACE HIGH PRESSURE EVENTUALLY SINKING SOUTH INTO THE
DELMARVA BY SUNDAY AFTERNOON...EXPECTING A DRY AND POSSIBLY
SLIGHTLY BELOW NORMAL WEEKEND. THIS HIGH WILL THEN DROP DOWN THE
EAST COAST AS THE UPPER TROUGH OVER NEW ENGLAND MOVES OUT TO
SEA...AND UPPER RIDGING TAKES HOLD THROUGH THE ENTIRE EASTERN US.
LOW CLOUDS AND FOG WILL DEVELOP OVERNIGHT WHILE THE WEDGE REMAINS
THIS WEEKEND...THEN BURN OFF DURING THE LATE MORNING AND
AFTERNOON. WINDS FINALLY VEER TO THE SW BY MONDAY...DELIVERING
MORE INSTABILITY AND A CHANCE FOR SHOWERS AND THUNDERSTORMS
THROUGH SE WEST VIRGINIA BY LATE DAY. H85 TEMPS MAY FALL TO 8C IN
THE VA PIEDMONT ON SUNDAY...BUT RAPID WAA ON SW WINDS MONDAY WILL
PUSH H85 TEMPS BACK TO 15C ON MONDAY.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 245 PM EDT THURSDAY...
THE UPPER FLOW PATTERN NEXT WEEK FEATURES A PERSISTENT UPPER RIDGE
CENTERED OVER NORTHERN MEXICO...EXTENDING EAST ACROSS THE SOUTHERN
CONUS...INCLUDING THE SOUTHEAST STATES. NORTH OF THIS RIDGE...A
MORE ZONAL TYPE PATTERN WILL EXISTS ACROSS THE CENTRAL AND NORTHERN
CONUS...ALTHOUGH VERY NOISY...WITH EMBEDDED SHORT WAVE ENERGY
RIPPLING EAST WITHIN THE FASTER WESTERLY WINDS ALOFT.
WITH THE EXTENSION OF THE UPPER RIDGE COVERING THE SOUTHEAST STATES
WINDS SURFACE AND ALOFT WILL BE OUT OF THE WEST OR SOUTHWEST. THIS
WILL FAVOR A MORE SUMMER LIKE PATTERN WITH TEMPERATURES CLIMBING
ABOVE NORMAL...MODEL GUIDANCE SUGGESTING READINGS ABOUT 10 DEGREES
ABOVE THE NORM FOR DAYTIME HIGHS AND AT LEAST 5 DEGREES ABOVE THE
NORM FOR OVERNIGHT LOWS.
THE PATTERN ALSO SUGGESTS THE FORECAST AREA WILL BE SUBJECT TO A
DAILY THREAT OF SHOWERS AND THUNDERSTORMS...NOTHING ORGANIZED PER SE
OR LASTING FOR ANY SIGNIFICANT LENGTH OF TIME...BUT MAINLY SCATTERED
IN NATURE. IF THERE IS ANYTHING CLOSE TO BEING ORGANIZED IF WILL
MOST LIKELY COME FROM SOMETHING GENERATED OVER THE OHIO VALLEY
ASSOCIATED WITH ONE OF THE SHORTWAVE DISTURBANCES ALOFT...THIS
ACTIVITY POTENTIALLY MOVING DOWNSTREAM INTO OUR FORECAST AREA IN THE
FORM OF THUNDERSTORM CLUSTERS OR A SQUALL LINE. OUTSIDE OF THIS
UPSTREAM THREAT...LOCAL THUNDERSTORM DEVELOPMENT WILL BE THE TYPICAL
DIURNALLY DRIVEN DEEP CONVECTION...WITH BEST CHANCES IN THE
MOUNTAINS ESPECIALLY ALONG THE BLUE RIDGE WHERE WIND CONVERGENCE
WILL BE THE GREATEST. IF THE WINDS ALOFT BECOME PURE WESTERLY...A
LEE TROUGH WILL FORM OVER THE PIEDMONT WHICH COULD AID IN SCATTERED
LATE AFTERNOON STORM DEVELOPMENT THERE TOO.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
AS OF 740 AM EDT FRIDAY...
DIFFUSE BACKDOOR FRONT EVIDENT ACROSS THE WESTERN PART OF THE CWA
FROM ROUGHLY BLF-SIF. EARLIER SHRA ACTIVITY ACROSS NW NC
DISSIPATED AROUND 07Z. MOIST...EASTERLY MARITIME FLOW SETTING UP
ACROSS THE COASTAL PLAIN...SPREADING WESTWARD TOWARD THE BLUE
RIDGE WITH ATTENDANT WIDESPREAD IFR-LIFR CIGS IN PLACE EAST OF THE
ALLEGHANY FRONT. HEALTHY WEDGE...WHICH WILL AWAIT REINFORCEMENT
SAT-SUN AS SFC HIGH PRESSURE SPREADS TOWARD THE NE U.S. AND
NORTHERN MID-ATLANTIC REGION. THUS...EVEN FOR JUNE...FEEL LOW
CLOUDS WILL HANG TOUGH...LIFTING TO MVFR AFT 14/15Z...BUT LIKELY
REMAINING BKN-OVC THROUGHOUT THE DAY. ANY BREAKS IN THE OVC WILL
FILL BACK IN OVERNIGHT. FOG HAS BEEN MORE PATCHY...BUT AT A FEW
SPOTS IS LIFR...SUCH AS LWB. VSBYS SHOULD IMPROVE TO MVFR OR
BETTER AFT 15Z...BUT WITH NE FLOW EXPECT HZ TO PREVAIL MUCH OF THE
DAY EAST OF THE BLUE RIDGE. WINDS ...NE-ESE THROUGH THE TAF VALID
PERIOD AT SPEEDS OF 5-7KTS. SHRA/TSRA THIS AFTERNOON SHOULD
REMAIN WEST- SOUTH OF THE BACKDOOR FRONT...MAINLY WEST OF A BLF-
SIF LINE.
MEDIUM CONFIDENCE IN CIGS AND VSBYS THROUGH THE TAF VALID PERIOD.
MEDIUM TO HIGH CONFIDENCE IN WIND DIR/SPD THROUGH THE TAF VALID
PERIOD.
EXTENDED AVIATION DISCUSSION...
INTO FRIDAY NIGHT...IFR CONDITIONS COULD RETURN OR CONTINUE...FOR
BLF AND LWB MAINLY...LOWER CONFIDENCE AT BCB...WITH SOME LOW LEVEL
MOISTURE TRAPPED BELOW INVERSION AND DEEPER MOISTURE IS PUSHED
FURTHER WEST AS DRY AIR ADVECTS SWWD TOWARD THE PIEDMONT. THEN
VFR CONDITIONS WILL PREVAIL FOR THE WEEKEND...EXCEPT FOR BRIEFLY
OVERNIGHT IN MOUNTAIN VALLEYS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RAB
NEAR TERM...KK/RAB
SHORT TERM...KM
LONG TERM...PM
AVIATION...RAB/SK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
251 PM CDT FRI MAY 30 2014
.SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT)
ISSUED AT 251 PM CDT FRI MAY 30 2014
ON THE CONUS SCALE...WATER VAPOR AND RAP 500MB ANALYSIS SHOW A REX
BLOCK PATTERN WITH A CUTOFF LOW ALONG THE TX/OK/AR BORDERS AND A
RIDGE OF HIGH PRESSURE SITUATED ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY REGION INTO WESTERN ONTARIO/HUDSON BAY. MAIN FORECAST
CONCERN IS WITH THE RAIN CHANCES FOR SATURDAY THROUGH SUNDAY. A DEEP
TROUGH OF LOW PRESSURE EXTENDING FROM THE CENTRAL PLAINS OF CANADA
TO ALONG THE WEST COAST WAS DIRECTING A PLUME OF TROPICAL
MOISTURE/FUEL FOR SCATTERED SHOWERS AND THUNDERSTORMS INTO THE FRONT
RANGE OF THE ROCKIES AND INTO THE WESTERN NORTHERN PLAINS. VISIBLE
SATELLITE SHOWING CLEAR SKIES ACROSS OUR AREA WITH FIELD OF CUMULUS
ACROSS MOST OF IA INTO THE MAJORITY OF MN IN RETURN FLOW AROUND
SURFACE HIGH PRESSURE SITUATED OVER THE GREAT LAKES REGION.
OTHERWISE...ANOTHER WARM ONE WITH TEMPERATURES ACROSS THE AREA THIS
AFTERNOON IN THE 80S.
FOR TONIGHT...RIDGE OF HIGH PRESSURE WILL KEEP OUR AREA QUIET AND
MOSTLY CLEAR THROUGH MUCH OF THE NIGHT. LOOK FOR SOME INCREASE IN
MID/HIGH CLOUD AFTER MIDNIGHT WEST OF THE MISSISSIPPI WITH EASTWARD
ADVANCE OF THE TROUGH PUSHING INTO THE NORTHERN PLAINS. LIGHT/CALM
WINDS AND CLEAR SKIES WILL LIKELY LEAD TO SOME PATCHY FOG IN THE
CRANBERRY BOG COUNTRY OF CENTRAL WISCONSIN AND IN THE WISCONSIN
RIVER VALLEY. OTHERWISE...PLAN ON LOWS TONIGHT IN THE LOWER/MIDDLE
50S ACROSS CENTRAL WISCONSIN...TO THE LOWER/MIDDLE 60S WEST OF THE
MISSISSIPPI RIVER.
ON SATURDAY...MODELS SHOW SURFACE HIGH HOLDING STRONG OVER THE GREAT
LAKES WHILE A MID-LEVEL TROUGH AND WEAK SURFACE COLD FRONT ADVANCES
EAST ACROSS THE NORTHERN PLAINS. AS A RESULT NAM/GFS/HIRES ECMWF ALL
SHOWING MAIN CORRIDOR OF 850MB MOISTURE TRANSPORT REMAINING WEST OF
THE AREA WITH THE EASTERN PERIPHERY BRUSHING AREAS WEST OF THE
MISSISSIPPI RIVER. THINKING WE WILL SEE A GENERAL INCREASE IN MID-
LEVEL ACCAS THROUGH THE DAY BUT HELD ANY SHOWER/THUNDER CHANCES WEST
OF THE MISSISSIPPI THROUGH THE DAY. DESPITE INCREASING CLOUD
COVER...TEMPERATURES EXPECTED TO TOP OFF IN THE 80-85 DEGREE RANGE
WITH SOUTH WINDS OF 10-15 MPH.
LOOK FOR A GENERAL UPTICK IN SHOWER/THUNDERSTORM CHANCES SATURDAY
NIGHT WITH THE APPROACHING MID-LEVEL TROUGH/SURFACE FRONTAL BOUNDARY
FOCUSING BETTER MOISTURE TRANSPORT INTO THE AREA. HIGHEST CHANCES
LOOK TO BE NORTH OF THE I-94 CORRIDOR. NOT EXPECTING ANY SEVERE AT
THIS POINT WITH 0-3KM MUCAPE ONLY IN THE 500-800J/KG RANGE AND SHEAR
WITHIN THIS CAPE LAYER ONLY IN THE 10-15KT RANGE. THINKING WITH
PRECIPITABLE WATERS CREEPING UP AROUND 1.5 INCHES...SOME LOCALIZED
HEAVY DOWNPOURS COULD OCCUR.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 251 PM CDT FRI MAY 30 2014
FOR SUNDAY THROUGH MONDAY...THERE WILL BE A LIKELIHOOD FOR SHOWERS
AND THUNDERSTORMS AS A SURFACE LOW SPINS UP OVER THE CENTRAL PLAINS
AND TRACKS NORTHEAST EASTERN MN/NORTHWEST WI. MOST FAVORABLE PERIOD
FOR SEVERE WEATHER SEEMS TO BE ON MONDAY AS BOTH THE NAM/GFS PRODUCE
A CORRIDOR OF PRE-FRONTAL 0-3KM MUCAPE IN THE 1500-3000J/KG RANGE
ALONG WITH 0-3KM BULK SHEAR IN THE 25-35KT RANGE. NAM ALSO SHOWS 700-
500MB LAPSE RATES APPROACHING 7-8C/KM. SO...APPEARS TO BE A WINDOW
OF OPPORTUNITY FOR SEVERE THREAT. WE WILL HAVE TO KEEP A CLOSE EYE
ON THIS.
FOR MONDAY NIGHT INTO TUESDAY...GFS AND ECMWF SHOW DEEPENING SURFACE
LOW MOVING NORTH OF THE AREA WITH A DRY SLOT WORKING INTO THE AREA.
THIS LOOKS TO SHUT DOWN SHOWER/THUNDER CHANCES AT LEAST FOR AREAS
ALONG AND WEST OF THE MISSISSIPPI RIVER...WITH BEST CHANCES
BASICALLY CONFINED ALONG AND NORTH OF THE I-94 CORRIDOR. ADJUSTED
POPS TO REFLECT THIS. LOOK FOR COOLER AIR OTHERWISE ON BRISK WEST
WINDS TUESDAY WITH HIGHS IN THE 70S.
FOR THE REMAINDER OF THE PERIOD...WED-FRI...ECMWF AND GFS SHOWING A
GENERALLY FLATTENED MID-LEVEL RIDGE ACROSS THE CONUS WITH SEVERAL
TROUGHS RIPPLING THROUGH THIS QUASI-HIGH ZONAL FLOW. APPEARS AT THIS
POINT THE BEST CHANCES OF RAIN WILL BE ON WEDNESDAY/WEDNESDAY NIGHT
AS BOTH MODELS SHOW PRETTY GOOD AGREEMENT IN BRING A FAIRLY STRONG
MID-LEVEL TROUGH THROUGH THE AREA. OTHERWISE...LOOKING AT A GENERAL
COOLING TREND FOR WEDNESDAY INTO THURSDAY WITH HIGHS WED IN THE 70-
75 DEGREE RANGE AND IN THE MID 60S/LOWER 70S FOR THU. HIGHS LOOK
LIKE THEY REBOUND INTO THE UPPER 60S TO MIDDLE 70S ON FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1229 PM CDT FRI MAY 30 2014
HIGH PRESSURE CENTERED OVER THE GREAT LAKES WILL CONTINUE TO PROVIDE
A DRY FEED OF AIR INTO THE TAF SITES FOR THE NEXT 24
HOURS...MAINTAINING VFR CONDITIONS. HOWEVER...LOWER LEVEL MOISTURE
IS ON THE INCREASE...WHICH MEANS A FEW CUMULUS CLOUDS COULD FORM AT
RST THIS AFTERNOON WITH MORE CUMULUS CLOUDS EXPECTED AT RST LATE
SATURDAY MORNING. RST MAY SEE SOME SHOWERS COME LATE SATURDAY
AFTERNOON. PLAN ON SOUTHEAST TO SOUTH WINDS TO REMAIN AT 10 KT OR
LESS INTO EARLY SATURDAY AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...AJ