Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/12/14
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
946 AM MDT SUN AUG 10 2014
.UPDATE...
ISSUED AT 946 AM MDT SUN AUG 10 2014
WILL MAKE SOME SLIGHT ADJUSTMENTS TO THE FORECAST TO DECREASE THE
CLOUD COVER THROUGH TODAY...BASED ON THE CLEAR SKIES DEPICTED ON
THE VISIBLE SATELLITE IMAGERY THIS MORNING. WILL ALSO DIMINISH
THE COVERAGE OF SHOWERS ACROSS THE PLAINS...AS THE LATEST RUNS OF
THE RAP CONTINUE KEEPING ALL OF THE SHOWER ACTIVITY OVER THE
MOUNTAINS THIS AFTERNOON AND EVENING. THE COOLER AIR THAT MOVED
INTO THE STATE OVERNIGHT WILL KEEP THE AIRMASS ON THE PLAINS MORE
STABLE THROUGH THIS AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 339 AM MDT SUN AUG 10 2014
A WEAK COLD FRONT PUSHED THROUGH THE AREA YESTERDAY EVENING. A
NORTH TO NORTHEAST FLOW BEHIND IT TODAY WILL USHER IN COOLER
TEMPERATURES AND DRIER AIR. PRECIPITABLE WATER VALUES WILL BE SIX
TO EIGHT TENTHS OF AN INCH ACROSS NORTHEAST COLORADO. CAPES WILL
BE LESS THAN 300 J/KG OVER THE NORTHEAST CORNER TO 400-800 J/KG
ALONG THE FOOTHILLS AND MOUNTAINS. EXPECT ANOTHER ROUND OF
SCATTERED THUNDERSTORMS OVER THE MOUNTAINS AND FOOTHILLS TODAY. A
FEW OF THESE MAY BE ABLE TO MOVE OFF THE HIGHER TERRAIN. THOUGH
CONDITIONS BECOME LESS FAVORABLE EASTWARD FROM THE FOOTHILLS. WILL
HAVE SLIGHT CHANCE EAST OF I-25 TO NO MENTION OF STORMS OVER THE
NORTHEAST CORNER. A BRIEF PERIOD OF MODERATE TO HEAVY RAIN WILL BE
POSSIBLE FROM THE STRONGER STORMS. GUSTY OUTFLOW WINDS WILL ALSO
BE POSSIBLE. HIGHS TODAY WILL BE COOLER WITH READINGS IN THE UPPER
70S TO MID 80S ACROSS NORTHEAST COLORADO.
THE STORMS WILL DECREASE QUICKLY EARLY THIS EVENING AS THE AIRMASS
STABILIZES. IT WILL BE ON THE COOL SIDE TONIGHT BECAUSE OF THE
CLEARING SKIES AND DRY AIRMASS. EXPECT LOWS TO BE IN THE 50S ACROSS
NORTHEAST COLORADO.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 339 AM MDT SUN AUG 10 2014
THE UPPER RIDGE IS CENTERED OVER COLORADO MONDAY THROUGH TUESDAY
AFTERNOON. THE UPPER RIDGE AXIS IS OVER THE WESTERN COLORADO
BORDER MONDAY MORNING. IT WILL MOVE TO EASTERN COLORADO BY 12Z
WEDNESDAY MORNING. THE FLOW ALOFT FOR THE CWA IS NORTHWESTERLY
THROUGH THE PERIODS. THE SYNOPTIC SCALE ENERGY REMAINS BENIGN FOR
THE CWA ALL FOUR PERIODS. THE BOUNDARY LAYER FLOW PROGGS SHOW
NORMAL DIURNAL PATTERNS TO PREVAIL. FOR MOISTURE...THERE IS STILL
SOME AROUND THROUGH THE PERIODS...NOTHING SIGNIFICANT. ALTHOUGH BY
TUESDAY NIGHT...THERE IS QUITE A BIT IN THE UPPER LEVELS. THE
PRECIPITABLE WATER VALUES ARE PROGGED IN THE 0.60 TO 1.00 INCH
RANGE MONDAY THROUGH TUESDAY NIGHT. THE BOUNDARY LAYER DEW POINTS
ARE PROGGED IN THE MID 40S F FOR THE WESTERN CWA TO THE UPPER 50S
F EAST THROUGH THE PERIOD. THE CAPE IS FAIR THROUGH THE PERIOD...WITH
VALUES IN THE 400-1200 J/KG DURING THE LATE DAY PERIODS FOR MOST
OF THE CWA. THE QPF FIELDS HAVE LIMITED AMOUNTS OF MEASURABLE
RAINFALL...MOSTLY OVER THE WESTERN HALF OF THE CWA FOR THE LATE
DAY PERIODS. FOR POPS...WILL GO WITH "CHANCE"S OVER THE HIGH
COUNTRY BOTH LATE DAY PERIODS...AND "SLIGHT CHANCE"S FOR THE
PLAINS. FOR TEMPERATURES...MONDAY`S HIGHS ARE 1-4 C WARMER THAN
TODAY`S. TUESDAY`S HIGHS ARE 1-2 C WARMER THAN MONDAY`S. FOR THE
LATER DAYS...WEDNESDAY THROUGH SATURDAY...MODELS HAVE THE UPPER
RIDGE AXIS OVER THE CWA WEDNESDAY. THERE IS A WEAK UPPER TROUGH TO
MOVE ACROSS ON THURSDAY. THERE IS FLAT UPPER RIDGING ON FRIDAY...
ANOTHER UPPER TROUGH FOR SATURDAY. THERE WILL BE SOME MOISTURE
AROUND WITH THE HIGHS POPS EXPECTED FOR THE MOUNTAINS AND
FOOTHILLS. TEMPERATURES LOOK TO BE PRETTY WARM...RIGHT NEAR
SEASONAL NORMALS.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z MONDAY MORNING)
ISSUED AT 946 AM MDT SUN AUG 10 2014
AFTERNOON AND EVENING SHOWER ACTIVITY LOOKS LIKE IT WILL BE
CONFINED TO THE MOUNTAINS...FOOTHILLS AND VERY ADJACENT PLAINS. NO
NEED TO MENTION ANY THUNDER AT KDEN. STRONG RIDGING WILL BE
BUILDING OVER THE ROCKY MOUNTAINS OVER THE NEXT 24 HOURS WHICH
WILL BE KEEPING DAILY CONVECTION OVER THE MOUNTAINS AND WEST OF
THE RIDGE AXIS. DRY WEATHER WITH MINIMAL AVIATION IMPACTS IS
EXPECTED FOR MONDAY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DANKERS
SHORT TERM...MEIER
LONG TERM...RJK
AVIATION...DANKERS
AREA FORECAST DISCUSSION
NWS MIAMI FL
843 PM EDT MON AUG 11 2014
.UPDATE...
CONVECTION HAS HELD ON A LITTLE LONGER THAN PREVIOUS THINKING.
HOWEVER, IT IS BEGINNING TO DIMINISH IN MANY ARES. BUT, DEVELOP IN
PORTIONS OF PALM BEACH COUNTY. THE HRRR IS NOT DOING TO WELL ON PICKING
UP ON THE CONTINUING CONVECTION. SO HAVE ANTICIPATED, BASED ON THE
CURRENT TRENDS, THAT IT WILL CONTINUE TO MOVE SLOWLY EAST AND
CONTINUE TO SHRINK IN COVERAGE OVER THE NEXT COUPLE OF HOURS,
ESPECIALLY IN PALM BEACH AS OBS DO NOT SHOW ANY SIGNIFICANT
EASTERLY FLOW TO KEEP THEM TO THE WEST OF THE COAST FROM WEST PALM
BEACH NORTH, WHERE PRECIPITATION IS ALREADY ENCROACHING ON THE
AREA. SOUTH OF THERE, CONVECTION IS FURTHER WEST, AND SHOWING
SIGNS OF WEAKENING.
&&
.PREV DISCUSSION... /ISSUED 719 PM EDT MON AUG 11 2014/
AVIATION...
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST WITH LIGHT
SURFACE WINDS. EXPECT L/V WIND THROUGH EARLY TUESDAY WITH SEA
BREEZES DEVELOPING ALONG BOTH COASTS AFT 14-16Z. THESE BOUNDARIES
WILL GENERATE SCATTERED SHRA/TSRA WITH VERY LITTLE STORM MOTION.
DUE TO THE SLOW MOVEMENT, THE PROBABILITY OF A CELL MOVING ACROSS
A TERMINAL IS VERY SMALL AND WILL NOT MENTION IN THE TAFS AT THIS
TIME.
KOB
PREV DISCUSSION... /ISSUED 258 PM EDT MON AUG 11 2014/
SHORT TERM...(TODAY-WEDNESDAY)...
BASED ON THIS MORNING`S SOUNDING AND OTHER DATA...A SAHARAN AIR
LAYER IS PRESENT TODAY ESPECIALLY WHEN LOOKING AT THE H85-H7
PORTION OF THE SOUNDING...AND SHOULD HELP LIMIT COVERAGE TODAY.
HOWEVER A FEW SLOW MOVING CELLS WERE PERSISTING ALONG THE SEA
BREEZE THROUGH CENTRAL DADE AND SOUTHEAST BROWARD. WITH WEAK FLOW
THESE STORMS WILL BE SLOW MOVING AND COULD PRODUCE VERY HEAVY
RAINFALL LEADING TO WATER PROBLEMS ALONG TYPICAL FLOOD PRONE
STREETS. MORE DEVELOPMENT IS STILL EXPECTED THROUGH THE INTERIOR
AND CAN`T RULE OUT ADDITIONAL DEVELOPMENT NEAR THE CITIES OR THE
COASTS LATE THIS AFTERNOON OR THIS EVENING. THE DEEP LAYER RIDGE
WILL REMAIN IN PLACE TOMORROW...BUT WILL WEAKEN EVENTUALLY INTO
WEDNESDAY AS ANOTHER UPPER TROUGH DIVES ACROSS THE GREAT LAKES AND
INTO THE MIDDLE ATLANTIC. IN ADDITION...A FEW WEAK DISTURBANCES
NOW MOVING ACROSS CUBA WILL BE PULLED BACK NORTH IN RESPONSE TO A
TROUGH ENTERING THE SOUTHEAST COAST. THIS COULD LEAD TO MORE
DEVELOPMENT IN COMPARISON TO WHAT IS EXPERIENCED FOR THE REST OF
TODAY AND TUESDAY. PWATS ARE ALSO FORECAST TO RISE CLOSER TO 2"
AGAIN ON WEDNESDAY PER MODEL SOUNDINGS. A GENERALLY SOUTHERN WIND
DIRECTION WILL CONTINUE THROUGH THE SHORT TERM...AND THE BEST
CHANCE FOR SHOWERS AND THUNDERSTORMS WILL REMAIN THROUGH THE
INTERIOR SECTIONS INTO WEDNESDAY.
LONG TERM...(THURSDAY-SUNDAY)...
THE LATEST EXTENDED GUIDANCE REMAINS IN DECENT AGREEMENT AND
GENERALLY INDICATES THE DEEP LAYER RIDGE REMAINING IN CONTROL ACROSS
THE REGION THROUGH THURSDAY. THIS COMBINED WITH PLENTY OF MID/UPPER
DRY AIR SHOULD KEEP THE RAIN CHANCES BELOW NORMAL WITH MAINLY
SCATTERED AFTERNOON SHOWERS ACROSS THE INTERIOR/LAKE REGION EACH
AFTERNOON. THE DEEP LAYER RIDGE IS PROGGED TO SLIGHTLY WEAKEN FRIDAY
INTO THE UPCOMING WEEKEND AS AN UPPER TROUGH DEEPENS ONCE AGAIN
ACROSS THE EASTERN STATES AND A WEAKENING FRONTAL BOUNDARY
ASSOCIATED WITH A SHORTWAVE TROUGH PUSHES SOUTH ACROSS THE REGION.
THIS COULD TRANSLATE TO SW LOW LEVEL FLOW AND INCREASING MOISTURE
AND RAIN CHANCES EACH DAY THROUGH THE WEEKEND ACROSS THE LOCAL AREA.
AVIATION...
SHOWERS ARE JUST STARTING TO POP UP TO THE WEST OF TERMINALS KFLL
AND KOPF AND KMIA. THEREFORE EAST COAST TERMINALS EITHER ASSIGNED
VCTS AT 18Z OR 19Z ESPECIALLY AS THE EAST COAST SEA BREEZE
CONTINUES TO PUSH FURTHER INLAND. THE SEA BREEZE NEAR KPBI HAS
NOT FORMED WITH A WEAK WESTERLY WIND AT TAF ISSUANCE WITH A WEAK
SEA BREEZE ASSIGNED AT 19Z. WITH ON-SET OF WEST COAST SEA BREEZE
ALREADY UNDERWAY...CONVECTION IS EXPECTED MAINLY INLAND OF
TERMINAL KAPF. WHILE CONVECTION IS EXPECTED TO BE MAINLY INLAND
AND WEST OF THE EASTERN TERMINALS...THERE COULD BE BRIEF PERIODS
OF SUB- VFR CONDITIONS WITH OCCURRENCE OF SHOWERS/THUNDERSTORMS.
MARINE...
HIGH PRESSURE WILL REMAIN IN CONTROL ACROSS THE MARINE AREAS THROUGH
MUCH OF THE WEEK WITH GENERALLY SOUTH WINDS 5-10 KTS EXPECTED.
MINOR STREET FLOODING OR STANDING WATER OVER THE TYPICAL MIAMI BEACH
AREAS ALONG THE BAY SIDE WILL REMAIN POSSIBLE THROUGH TUESDAY
MORNING`S HIGH TIDE DUE TO THE LUNAR PERIGEE. REPORTS FROM SUNDAY
EVENING`S HIGH TIDE INDICATED A SMALL AMOUNT OF WATER ON THE
STREETS...HOWEVER...NOT ENOUGH TO CLOSE ROADS OR FOR A COASTAL FLOOD
STATEMENT. THE UPCOMING HIGH TIDES WILL BE AT OR AROUND: 940 AM
TODAY AND 1009 PM THIS EVENING...WHICH ARE PREDICTED TO BE
SLIGHTLY HIGHER THAN SUNDAY`S HIGH TIDE CYCLES.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 76 90 79 90 / 20 20 10 30
FORT LAUDERDALE 81 92 82 91 / 10 20 10 30
MIAMI 79 92 81 91 / 10 20 10 40
NAPLES 77 94 77 92 / 10 20 10 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...13/SI
LONG TERM....85/AG
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
345 PM EDT SUN AUG 10 2014
.SYNOPSIS...
19Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUE TO SHOW THE MAIN BAND
OF WESTERLIES LOCATED WELL TO OUR NORTH THIS MORNING AS A WEAK AND
NARROW BAND OF MID/UPPER LEVEL RIDGING EXTENDS FROM EAST OF THE
BAHAMAS OVER THE CENTRAL/NORTHERN FL PENINSULA AND INTO THE GULF OF
MEXICO. LARGEST AMPLITUDE TROUGH WITHIN THE NORTHERN STREAM FLOW
CONTINUES TO PULL EAST OF NEW ENGLAND THIS MORNING WITH THE ONLY
OTHER SIGNIFICANT ENERGY OVER THE CONUS BEING A SHORTWAVE
PROGRESSING ACROSS THE NORTHERN PLAINS AND BRINGING A FEW ROUNDS OF
SHOWERS/STORMS TO THE UPPER MIDWEST/CENTRAL PLAINS.
THE HIGH LEVEL VORTICITY CENTER/CLOSED LOW THAT WAS ILL-DEFINED OVER
THE SOUTHERN BAHAMAS ON SATURDAY IS NOW A BIT MORE VISIBLE IN WV
IMAGERY AS IT SLIDES WESTWARD THROUGH THE FLORIDA STRAITS. THIS
FEATURE IS MOST DEFINED ABOVE 500MB...AND NWP GUIDANCE HAS NOT
CHANGED IN KEEPING THIS ENERGY ON A PROGRESSIVE WESTWARD TRACK INTO
THE SE GOMEX BY MONDAY. SOME DRIER AIR ON THE WESTERN/NORTHERN
PERIPHERY OF THE CIRCULATION HAS WORKED ITS WAY INTO THE SOUTHERN FL
PENINSULA...BUT WILL GENERALLY STAY TO OUR SOUTH/SE DURING THE
DIURNAL CONVECTIVE CYCLE TODAY. SOME INDICATIONS THAT SOME OF THIS
DRIER AIR WILL COME FURTHER NORTH EARLY IN THE WEEK...BUT THE DEGREE
OF DRY AIR DOES NOT APPEAR TO BE ENOUGH TO HAVE ANY SIGNIFICANT
IMPACT ON THE CONVECTIVE FAVORABILITY OF THE ATMOSPHERIC COLUMN.
SUBTROPICAL RIDGE AXIS IS SUPPRESSED JUST TO THE SOUTH OF FORT MYERS
BY A COMPLEX FRONTAL SYSTEM OVER THE SOUTHEAST CONUS. THIS
CONFIGURATION IS SUPPLYING A 1000-700MB MEAN SYNOPTIC FLOW FROM THE
SW (MOST DEFINED NORTH OF TAMPA IN LESS PROXIMITY TO THE RIDGE
AXIS).
&&
.SHORT TERM (REST OF TODAY THROUGH MONDAY)...
REST OF TODAY AND THIS EVENING...
WELL...THIS HAS BEEN "ONE OF THOSE DAYS" IN TERMS OF KEEPING UP WITH
THE FORECAST. THE NWP SUITES FROM YESTERDAY THAT WERE SUGGESTING AN
ACTIVE CONVERGENCE BAND TO THE NORTH OF TAMPA BAY TODAY WERE OFF BY
A FEW HOURS ON INITIATION...BUT WERE CERTAINLY RIGHT THAT IT WOULD
DEVELOP. HAVE ENDED UP WITH QUITE A WET DAY/FORECAST TO THE NORTH OF
THE I-4 CORRIDOR...AND THE WIDESPREAD SHOWERS/CLOUDS HAVE PLAYED
HAVOC WITH THE DIURNAL TEMPERATURES AND WHAT WAS SUPPOSED TO BE A
DECENT SEA-BREEZE CIRCULATION. THIS SEA-BREEZE CIRCULATION WAS
SUPPOSED TO HELP DISSIPATE THE CONVERGENCE BAND AND BRING DRIER
CONDITIONS TO THE COASTAL AREAS OF THE NATURE COAST AND TAMPA BAY
THIS AFTERNOON. WITHOUT THIS SUBSIDENCE/DIVERGENCE IN THE WAKE OF
THE NON-EXISTENT SEA BREEZE...THE SHOWERS AND STORMS HAVE CONTINUED
TO ROLL ONSHORE AND LOOK TO CONTINUE BEING A FORECAST ISSUE FOR A
FEW HOURS TO COME. IN FACT...IT NOW LOOKS LIKE THE MAIN BAND HAS
SETTLED A BIT FURTHER SOUTH AND CONDITIONS ARE GOING TO GET WETTER
INTO THE TAMPA BAY AREA AGAIN...ESPECIALLY ALONG THE 275/I-4
CORRIDOR. THIS IS ONE OF THOSE EXAMPLES WHERE JUST ONE VARIABLE NOT
COMING TOGETHER HAS MADE FOR A SIGNIFICANTLY DIFFERENT FORECAST THAT
WHAT WAS EXPECTED 12 HOURS AGO.
SO...THAT BEING SAID...WILL CONTINUE TO EXPECT AT LEAST SCT/NMRS
SHOWERS FOR A FEW MORE HOURS OVER THE NORTHERN HALF OF THE FORECAST
AREA...WITH LESS IN TERMS OF COVERAGE OVER THE SOUTH. SO FAR...THERE
HAS BEEN VERY LITTLE SOUTH OF HILLSBOROUGH/POLK COUNTIES...BUT DO
EXPECT SOME DEVELOPMENT OVER THE INLAND PORTIONS OF THE SOUTH INTO
THE EARLY EVENING. COASTAL AREAS SOUTH OF MANATEE COUNTY ARE LIKELY
TO REMAIN RELATIVELY DRY.
THERE MAY BE A BREAK/LESSENING OF THE ACTION OVER THE NE GULF/NATURE
COAST FOR A WHILE THIS EVENING...HOWEVER...THERE IS GOOD AGREEMENT
AMONG THE GUIDANCE THAT THE SOUTHWEST FLOW INTERACTING WITH A
STATIONARY FRONTAL BOUNDARY TO OUR NORTH WILL RESULT IN DEVELOPMENT
OF ANOTHER ORGANIZED CONVERGENT BAND LATE TONIGHT AND/OR MONDAY
MORNING FOR THE NATURE COAST. THIS TIME...ALL GUIDANCE MEMBERS ARE
ON BOARD...AND ALSO PIN THE BEST FOCUS A BIT FURTHER NORTH...PERHAPS
CITRUS/LEVY COUNTY INTO THE BIG BEND. WHILE THESE AREA MAY BE
FAVORED FOR NUMEROUS SHOWERS TOMORROW MORNING...WE COULD CERTAINLY
SEE A SCT OF SHOWERS FURTHER SOUTH TO THE I-4 CORRIDOR IF THE
SREF/ECMWF ARE ACCURATE. EVEN WITHOUT THE CONVERGENCE FOCUS...
WESTERLY FLOW IS FAVORED FOR LATE NIGHT SHOWER DEVELOPMENT...SO WILL
BRING CHANCE POPS DOWN INTO PINELLAS/HILLSBOROUGH COUNTIES.
MONDAY...WILL NOT SAY THAT MONDAY LOOKS LIKE A REPEAT OF
TODAY...BUT THE PATTERN IS SIMILAR. FORECAST CONFIDENCE ESPECIALLY
INTO THE AFTERNOON IS CERTAINLY HIGHER TO THE SOUTH OF I-4...WHERE A
TYPICAL SW FLOW CONVECTIVE PATTERN IS EXPECTED. WINDS ARE LIGHTER TO
THE SOUTH CLOSER TO THE RIDGE AXIS...AND MAY BE WEAK ENOUGH TO ALLOW
FOR A FEEBLE LAND BREEZE EARLY MONDAY MORNING. THE LAND BREEZE WOULD
LIKELY FORCE A FEW ISOLATED SHOWERS NEAR THE COAST EARLY IN THE
DAY...HOWEVER MOST OF THE CONVECTION FOR THE SOUTHERN HALF OF THE
AREA WILL BE WELL INLAND DURING THE AFTERNOON/EARLY EVENING. FROM
TAMPA BAY NORTHWARD...MUCH WILL DEPEND ON THE EVOLUTION OF THE
SHOWERS/STORMS THROUGH THE MORNING HOURS. IF THEY ARE PERSISTENT
AGAIN...THEN THE SEA-BREEZE WILL FAIL TO DEVELOP AND THE WET
CONDITIONS WILL VERY POSSIBLY LINGER INTO THE AFTERNOON HOURS. KEPT
LIKELY POPS IN THE GRIDS THROUGH 18Z FROM BROOKSVILLE
NORTHWARD...WITH CHANCE POPS THEREAFTER. NOT A PATTERN THAT ALLOWS
FOR GETTING TO DETAILED EITHER SPATIAL OR TEMPORALLY.
&&
.LONG TERM (MONDAY NIGHT-SUNDAY)...
MODEL SOLUTIONS ARE IN GOOD AGREEMENT SHOWING A LONG WAVE UPPER
TROUGH OVER THE WESTERN GREAT LAKES STATES MONDAY NIGHT AND
TUESDAY...DEEPENING AND CLOSING OFF AS IT SHIFTS INTO THE EASTERN
GREAT LAKES MID WEEK BEFORE SHIFTING INTO NEW ENGLAND AND THE
CANADIAN MARITIMES OVER THE UPCOMING WEEKEND. AT THE
SURFACE...THIS WILL DRIVE A FRONTAL BOUNDARY SOUTHWARD INTO NORTH
FLORIDA WHERE IT WILL STALL OUT THROUGH MUCH OF THE WEEK BEFORE
DISSIPATING FOR THE UPCOMING WEEKEND. THIS WILL ALSO KEEP THE
SURFACE HIGH PRESSURE RIDGE AXIS SUPPRESSED ACROSS THE FLORIDA
STRAIGHTS AND SOUTH FLORIDA THROUGH THE WORK WEEK. THE RIDGE AXIS
SHOULD THEN LIFT BACK NORTHWARD INTO CENTRAL FLORIDA OVER THE
UPCOMING WEEKEND. OVERALL...EXPECT FAIRLY TYPICAL SUMMER WEATHER
UNDER SOUTHWESTERLY BOUNDARY LAYER FLOW WITH SCATTERED SHOWERS AND
THUNDERSTORMS EACH DAY. THE SHOWERS AND STORMS WILL DEVELOP EACH
NIGHT OVER THE EASTERN GULF AND DRIFT INTO COASTAL ZONES PRIOR TO
DAYBREAK. THE ACTIVITY WILL THEN TRANSITION INLAND AND INCREASE IN
COVERAGE AND INTENSITY DURING THE AFTERNOON. TEMPERATURES ARE
EXPECTED TO RUN NEAR TO SLIGHTLY ABOVE NORMAL THROUGH THE LONG TERM
PERIOD.
&&
.AVIATION...
PERSISTENT CONVERGENT BAND OF SHOWERS AND STORMS HAS EXISTED ALL DAY
JUST TO THE NORTH OF KTPA/KPIE/KLAL. THESE TERMINALS WILL LIKELY GET
INTO SOME OF THIS ACTIVITY DURING THE NEXT FEW HOURS WITH BRIEF
VIS/CIG RESTRICTIONS POSSIBLE. FURTHER SOUTH...THE CHANCES ARE LOW
FOR SIGNIFICANT THUNDERSTORM ACTIVITY THE REST OF THE AFTERNOON. A
SIMILAR SETUP IS EXPECTED FOR MONDAY...WHICH HOPEFULLY WILL KEEP
MUCH OF THE STEADIER SHOWER/STORM ACTIVITY TO THE NORTH OF THE I-4
CORRIDOR THROUGH THE MORNING HOURS. OUTSIDE OF THE THE SCT
STORMS...VFR CONDITIONS WILL PREVAIL.
&&
.MARINE...
THE SUBTROPICAL RIDGE AXIS WILL BE ALIGNED ACROSS SOUTH-CENTRAL
FLORIDA THROUGH THE MIDDLE OF THE WEEK KEEPING WINDS AND SEAS
GENERALLY LOW. ANY GUSTIER FLOW WILL BE CONFINED TO LOCATIONS NORTH
OF TAMPA BAY WHERE THE GRADIENT WILL BE A BIT TIGHTER BETWEEN THE
RIDGE TO OUR SOUTH AND A FRONTAL BOUNDARY TO THE NORTH. SHOWERS AND
THUNDERSTORMS WILL DEVELOP DURING THE OVERNIGHT AND EARLY MORNING
HOURS OVER THE GULF AND NEAR-SHORE WATERS...ESPECIALLY NORTH OF
TAMPA BAY ALONG THE NATURE COAST. THIS ACTIVITY WILL FAVOR THE
MORNING HOURS AND THEN SHIFT INLAND EACH AFTERNOON. ONLY HAZARDS
WILL BE ISOLATED WATERSPOUTS...LIGHTNING...AND LOCALIZED GUSTY WINDS
IN AND NEAR THUNDERSTORMS.
&&
FIRE WEATHER...
RAIN CHANCES LOOK TO REMAIN HIGH NORTH OF THE I-4
CORRIDOR INTO MONDAY...WITH MORE TYPICAL COVERAGE OF SHOWERS AND
STORMS FURTHER TO THE SOUTH. OTHER THAN THE RAINFALL POTENTIAL...
NO SIGNIFICANT FIRE WEATHER CONCERNS ARE EXPECTED WITH RELATIVE
HUMIDITY VALUES REMAINING WELL ABOVE CRITICAL LEVELS THROUGH THE
MIDDLE OF THE WEEK.
FOG POTENTIAL...ISOLATED POCKETS OF SHALLOW PATCHY GROUND FOG
WILL BE POSSIBLE IN OPEN FIELDS EACH MORNING...BUT
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 79 92 78 92 / 20 30 20 20
FMY 76 94 77 94 / 10 20 20 20
GIF 76 94 76 94 / 20 40 10 30
SRQ 78 91 77 91 / 20 20 20 20
BKV 73 91 73 93 / 30 60 20 30
SPG 81 91 80 91 / 20 30 20 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/AVIATION/FIRE WEATHER...MROCZKA
LONG TERM...JELSEMA
AREA FORECAST DISCUSSION...UPDATE
NWS TAMPA BAY RUSKIN FL
1050 AM EDT SUN AUG 10 2014
...INCREASED RAIN CHANCES TO LIKELY FOR THE NATURE COAST THROUGH
EARLY AFTERNOON...
.LATE MORNING UPDATE (NEXT FEW HOURS)...
CONVECTIVE COVERAGE HAS INCREASED RAPIDLY SINCE SUNRISE OVER THE NE
GULF OF MEXICO WITH SCT-NMRS SHOWERS/STORMS MOVING ASHORE AND
DEVELOPING TO THE NORTH OF THE I-4 CORRIDOR. BASED ON THESE TRENDS
AND CONTINUED TERRESTRIAL HEATING HAVE INCREASED RAIN CHANCES NORTH
OF I-4 TO THE 60% LIKELY RANGE THROUGH THE EARLY AFTERNOON. STORMS
SHOULD THEN TEND TO MIGRATE INLAND RATHER QUICKLY THEREAFTER WITH
DECREASING RAIN CHANCES FOR THE NATURE COAST INTO THE SECOND HALF OF
THE AFTERNOON. THIS IS JUST A VERY SHORT TERM UPDATE FOR THE NEXT
FEW HOURS...AND THE FORECAST HAS NOT CHANGED BEYOND 18Z.
&&
.PREVIOUS MORNING UPDATE (REST OF TODAY THROUGH MONDAY)...
13Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUE TO SHOW THE MAIN BAND
OF WESTERLIES LOCATED WELL TO OUR NORTH THIS MORNING AS A WEAK AND
NARROW BAND OF MID/UPPER LEVEL RIDGING EXTENDS FROM EAST OF THE
BAHAMAS OVER THE CENTRAL/NORTHERN FL PENINSULA AND INTO THE GULF OF
MEXICO. LARGEST AMPLITUDE TROUGH WITHIN THE NORTHERN STREAM FLOW
CONTINUES TO PULL EAST OF NEW ENGLAND THIS MORNING WITH THE ONLY
OTHER SIGNIFICANT ENERGY OVER THE CONUS BEING A SHORTWAVE
PROGRESSING ACROSS THE NORTHERN PLAINS AND BRINGING A FEW ROUNDS OF
SHOWERS/STORMS TO THE UPPER MIDWEST/CENTRAL PLAINS.
THE HIGH LEVEL VORTICITY CENTER/CLOSED LOW THAT WAS ILL-DEFINED OVER
THE SOUTHERN BAHAMAS ON SATURDAY IS NOW A BIT MORE VISIBLE IN WV
IMAGERY AS IT SLIDES WESTWARD THROUGH THE FLORIDA STRAITS. THIS
FEATURE IS MOST DEFINED ABOVE 500MB...AND NWP GUIDANCE HAS NOT
CHANGED IN KEEPING THIS ENERGY ON A PROGRESSIVE WESTWARD TRACK INTO
THE SE GOMEX BY MONDAY. SOME DRIER AIR ON THE WESTERN/NORTHERN
PERIPHERY OF THE CIRCULATION HAS WORKED ITS WAY INTO THE SOUTHERN FL
PENINSULA...BUT WILL GENERALLY STAY TO OUR SOUTH/SE DURING THE
DIURNAL CONVECTIVE CYCLE TODAY. SOME INDICATIONS THAT SOME OF THIS
DRIER AIR WILL COME FURTHER NORTH EARLY IN THE WEEK...BUT THE DEGREE
OF DRY AIR DOES NOT APPEAR TO BE ENOUGH TO HAVE ANY SIGNIFICANT
IMPACT ON THE CONVECTIVE FAVORABILITY OF THE ATMOSPHERIC COLUMN.
10/12Z KTBW SOUNDING PROFILE IS SIMILAR (PERHAPS A TAD MORE MOIST)
THAN WE SAW ON SATURDAY. PW VALUES ARE AROUND 1.9"...STILL ABOVE
NORMAL...BUT NOT UNUSUAL FOR THE MIDDLE OF AUGUST. LAPSE RATES AGAIN
ARE ON THE POOR SIDE...AND HAVE SEEN TEMPERATURES ACTUALLY WARM A
DEGREE OR 2 IN THE MIDDLE TO UPPER LEVELS OF THE COLUMN DURING THE
PAST 24 HOURS. 500MB TEMPS WAS MEASURED -6C...WITH IS FAIRLY WARM.
IN ADDITION...THE FREEZING LEVEL IS NEAR 15KFT...AND WET BULB ZERO
NEAR 14KFT. THESE VALUES DO NOT SUGGEST MUCH IN THE WAY OF HAIL IS
LIKELY EITHER. SO THERE ARE ALL THE NEGATIVES FOR STRONGER
UPDRAFTS...HOWEVER...THE COLUMN IS NOT UNFAVORABLE FOR GENERAL
THUNDERSTORM ACTIVITY. THETA-E VALUES IN THE LOWER/MID LEVELS ARE
GENERALLY IN THE UPPER 320S TO LOWER 330S. THESE VALUES ARE NEAR OR
JUST ABOVE CLIMO FOR THIS TIME OF YEAR...AND SHOULD NOT PRESENT ANY
ENTRAINMENT ISSUES FOR GROWING CONVECTIVE COLUMNS. THEREFORE...
SIMILAR TO SATURDAY...THE THREAT FOR SEVERE PULSE STORMS IS NOT
ZERO...BUT IS RATHER LOW. "RUN OF THE MILL" SUMMER STRENGTH STORMS
APPEAR TO BE NORM.
WELL...THE AREA OF SHALLOW CONVECTION OVER THE EASTERN GULF IS WHERE
WE EXPECTED IT TO BE THIS MORNING (SARASOTA NORTHWARD)...HOWEVER THE
COVERAGE IS A BIT LESS THAN MOST OF THE NWP GUIDANCE MEMBERS WOULD
HAVE SUGGESTED 24 HOURS AGO. SURFACE ANALYSIS SHOWS THAT THE
EXPECTED CONVERGENCE BAND DID SET UP...WITH THAT THE MODELS WERE
A TAD AGGRESSIVE WITH THE STRENGTH OF THE CONVERGENCE...AND THAT
EXPLAINS THE LOWER COVERAGE. EITHER WAY...WILL CONTINUE TO SEE A SCT
OF SHOWERS MOVING TOWARD SHORE OVER THIS FAVORED REGION THE NEXT
SEVERAL HOURS.
SUBTROPICAL RIDGE AXIS IS SUPPRESSED JUST TO THE SOUTH OF FORT MYERS
BY A COMPLEX FRONTAL SYSTEM OVER THE SOUTHEAST CONUS. THIS
CONFIGURATION IS SUPPLYING A 1000-700MB MEAN SYNOPTIC FLOW FROM THE
SW (MOST DEFINED NORTH OF TAMPA IN LESS PROXIMITY TO THE RIDGE
AXIS). WOULD EXPECT A CONVECTIVE EVOLUTION PATTERN SIMILAR TO
SATURDAY WITH THIS SETUP AND GENERALLY SIMILAR SOUNDING PROFILE.
CONVECTIVE COVERAGE EXPECTED TO BECOME SCT ALONG AND INSIDE THE I-75
BY MIDDAY INTO THE EARLY AFTERNOON...WITH STORMS QUICKLY
MIGRATING/DEVELOPING INLAND BY THE SECOND HALF OF THE AFTERNOON.
HAVE LOW RAIN CHANCES INSIDE THE I-75 CORRIDOR AFTER 19Z THIS
AFTERNOON...AND THIS CONVECTIVE CLEARING LINE IS LIKELY TO MAKE EVEN
MORE INLAND PENETRATION DURING THE LATER AFTERNOON HOURS. HIGHEST
POPS BY 20Z SHOULD MOST CERTAINLY BE WELL INLAND. HIGH TEMPERATURES
THIS AFTERNOON INTO THE LOWER 90S INLAND AND UPPER 80S TO AROUND 90
AT THE BEACHES.
EVENING STORMS OVER THE INTERIOR DISSIPATE WITH THE LOSS OF DIURNAL
HEATING AND BOUNDARY FOCUS WITHIN A COUPLE HOURS OF SUNSET. A MOSTLY
DRY AND SEASONABLE OVERNIGHT WILL FOLLOW. LATE AT NIGHT...THE SW
FLOW (AS CLIMO WOULD SUGGEST) SHOULD BEGIN TO BUBBLE UP SHALLOW
CONVECTION OVER THE EASTERN GULF OF MEXICO...WITH THE SHOWERS
MIGRATING TO THE COAST BY DAWN. THE SW FLOW AND SOME ADDED FOCUS
CLOSER TO THE FRONT TO OUR NORTH WOULD SUGGEST BEST CHANCE FOR
SHOWERS TO REACH THE COAST WOULD BE TO THE NORTH OF TAMPA BAY.
HOWEVER...WILL KEEP SLIGHT CHANCE POPS FROM PINELLAS COUNTY
SOUTHWARD JUST IN CASE A WEAK LAND BREEZE CAN DEVELOP WITHIN THE
WEAKER GRADIENT NEAR THE RIDGE AXIS AND SET UP A BRIEF WINDOW OF
COASTAL CONVERGENCE AROUND SUNRISE.
TUESDAY...OVERALL LOOKS AS THOUGH WE WILL REPEAT THE FORECAST
PATTERN ONCE AGAIN WITH THE SUBTROPICAL RIDGE STILL IN THE SAME
GENERAL LOCATION. SW FLOW BRINGS A FEW STORMS TO COASTAL AREAS
THROUGH EARLY AFTERNOON...AND THEN PROGRESSES THE MAIN CONVECTIVE
ACTION INLAND. WILL HAVE TO TAKE A CLOSER LOOK AT THE POTENTIAL FOR
SOME DRIER AIR ALOFT...ESPECIALLY SOUTH OF THE I-4 CORRIDOR WITH THE
AFTERNOON FORECAST PACKAGE...HOWEVER AS MENTIONED ABOVE...AT THE
PRESENT TIME...IT DOES NOT APPEAR TO BE A DRY/DEEP ENOUGH TO BE A
BIG NEGATIVE INFLUENCE ON THE DIURNAL CONVECTION. HAVE A GREAT REST
OF YOUR SUNDAY EVERYONE!
&&
.AVIATION...
VFR CONDITIONS PREVAIL ACROSS WEST-CENTRAL AND SOUTHWEST FLORIDA
THIS MORNING. AS IS TYPICAL WITH WESTERLY FLOW...WIDELY SCT SHOWERS
ARE MIGRATING ONSHORE FROM THE GULF AND ANY OF THE COASTAL TERMINALS
MAY SEE A BRIEF SHOWER OVER THE NEXT SEVERAL HOURS. TOWARD
MIDDAY...COVERAGE WILL INCREASE FOR A BRIEF PERIOD OF TIME INTO THE
EARLY AFTERNOON ALONG AND WEST OF THE I-75 CORRIDOR...AND THIS WILL
BE THE BEST CHANCE FOR MOST OF THE TERMINALS TO SEE A STORM PASSAGE.
THEREAFTER...MUCH OF THE CONVECTIVE ACTIVITY WILL MOVE INLAND FROM
I-75...WITH KLAL THE MOST LIKELY PLACE TO SEE A BRIEF STORM AFTER
19Z. STORMS WILL FADE QUICKLY WITH SUNSET OVER THE INTERIOR THIS
EVENING WITH GENERAL VFR CONDITIONS CONTINUING TO PREVAIL INTO THE
OVERNIGHT.
&&
.MARINE...
THE SUBTROPICAL RIDGE AXIS WILL BE ALIGNED ACROSS SOUTH-CENTRAL
FLORIDA THROUGH THE START OF THE WEEK KEEPING WINDS AND SEAS LOW.
SHOWERS AND THUNDERSTORMS WILL DEVELOP DURING THE OVERNIGHT AND
EARLY MORNING HOURS OVER THE GULF AND NEAR-SHORE WATERS...
ESPECIALLY FROM TAMPA BAY NORTHWARD ALONG THE NATURE COAST. THIS
ACTIVITY WILL FAVOR THE MORNING HOURS AND THEN SHIFT INLAND EACH
AFTERNOON. THE AFTERNOON AND EVENING SEA BREEZE WILL INCREASE WINDS
TO AROUND 10 KNOTS ALONG THE COASTAL AREAS. ONLY HAZARDS WILL BE
ISOLATED WATERSPOUTS...LIGHTNING...AND LOCALIZED GUSTY WINDS IN AND
NEAR THUNDERSTORMS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 92 79 92 78 / 40 20 20 20
FMY 94 77 93 77 / 30 10 40 20
GIF 94 75 93 76 / 50 20 40 10
SRQ 91 77 91 77 / 40 20 20 20
BKV 92 73 92 73 / 40 20 40 20
SPG 91 80 91 80 / 40 20 20 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
LATE MORNING UPDATE/PREVIOUS MORNING UPDATE/AVIATION...MROCZKA
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1020 AM EDT SUN AUG 10 2014
.DISCUSSION...
LATEST RUC ANALYSIS OF THE H100-H70 LYR SHOWING A WELL DEFINED ATLC
RIDGE AXIS OVER S FL. INTERACTION WITH A FRONTAL TROF OVER THE SE
CONUS IS PRODUCING A DEEP LYR W/SW FLOW ACRS CENTRAL FL...MORNING
KTBW/KXMR/KJAX SOUNDINGS MEASURING 10-15KTS THRU THE H100-H50
LYR...BCMG S AND DECREASING ARND 5KTS AT KMFL. PWAT VALUES ARND 2.0"
AT KTBW/KXMR/KJAX DECREASING TO ARND 1.7" AT KMFL. RUC SHOWING THIS
BNDRY WITH H100-H70 MEAN RH VALUES BTWN 70-80PCT N OF THE I-4
CORRIDOR... DECREASING TO ARND 60PCT OVER S FL.
MID LVL LAPSE RATES ARE STEEPEST THRU THE H85-H70 LYR...BUT ONLY
5.8-6.3C/KM AT THAT. H70-H50 LAPSE RATES DROP TO ARND 5.5C/KM. THE
ACCOMPANYING MID LVL VORT FIELDS ARE UNIMPRESSIVE AS WELL...WEAK
AXIS EXTENDING FROM THE BIG BEND TO THE PALM COAST BUT NEARLY
FLATLINE IN THE VCNTY OF LAKE OKEECHOBEE. A 35KT NERLY JET MAX
CENTERED JUST N OF ANDROS ISLAND IS PLACING PORTIONS OF THE CWA
UNDER ITS DESCENDING LEFT EXIT QUAD...LEAVING THE H30-H20 LYR WEAKLY
CONVERGENT.
BETTER MOISTURE/DYNAMIC SUPPORT ALONG AND N OF THE I-4 CORRIDOR WILL
RESULT IN SLIGHTLY HIGHER COVERAGE...BUT STRONGER WINDS SHOULD
PREVENT THE FORMATION OF THE EAST COAST SEA BREEZE...LEAVING STORMS
WITHOUT A LOW LVL FOCUS. DRIER AND WEAKER DYNAMIC SUPPORT S OF I-4
WILL RESULT IN LOWER COVERAGE...BUT WEAKER WINDS SHOULD THE SEA
BREEZE TO FORM S OF SEBASTIAN INLET BY MID AFTN. IF IT DOES...THE
LOW LVL FOCUS WILL GIVE ANY TSTMS THE ABILITY TO TAP THE DRIER MID
LVL AIR...THUS ADDING TO THEIR DOWNBURST POTENTIAL.
IN A NUTSHELL...HIGHER COVERAGE/LOWER POTENTIAL N OF I-4...LOWER
COVERAGE/HIGHER POTENTIAL S OF I-4. WRLY FLOW WILL ALLOW MAX TEMPS
TO WARM INTO THE L/M90S.
&&
.AVIATION...
THRU 10/17Z...PREVAILING VFR ALL SITES...SFC WND SW 5-10KTS...ISOLD
MVFR SHRAS MVG E FM THE GULF COAST MAY AFFECT KLEE AFTER 10/15Z.
BTWN 10/17Z-10/19Z...SFC WNDSHFT TO SE ARND 10KTS BTWN KVRB-KSUA...
SCT MVFR SHRAS/IFR TSRAS DVLPG ALONG THE WEST COAST SEA BREEZE MVG
E/NE 10-15KTS. BTWN 10/19Z-10/22Z...SCT MVFR SHRAS/IFR TSRAS N OF
KMLB-KISM...SFC WND G3KTS PSBL IN ISOLD +TSRA. BTWN 10/22Z-11/01Z
SCT MVFR SHRAS/ISOLD TSRAS SHIFTING S OF KMLB-KISM WITH SFC WND
G3KTS PSBL IN ISOLD +TSRA...VFR N OF KMLB-KISM. AFT 11/02Z...VFR ALL
SITES...SW SFC WND AOB 5KTS.
&&
.MARINE...
WELL DEFINED ATLC RIDGE AXIS EXTENDING FROM THE NRN BAHAMAS INTO THE
CENTRAL GOMEX WILL GENERATE A GENTLE TO MODERATE W/SW BREEZE TODAY.
LATE AFTN SEA BREEZE MAY FORM S OF SEBASTIAN INLET...FORCING WINDS
TO VEER TO THE S/SE FOR A FEW HRS. OFFSHORE WIND COMPONENT WILL KEEP
THE LCL ATLC FETCH PROTECTED...RESULTING IN SEAS AOB 2FT OVER MOST
OF THE AREA WITH DOMINANT PDS ARND 9SEC. SLIGHTLY TIGHTER PGRAD N OF
SEBASTIAN INLET MAY GENERATE SUFFICIENT SFC WNDS TO ALLOW THE GULF
STREAM SEAS TO REACH THE 3FT MARK.
OFFSHORE MOVING STORMS THIS AFTERNOON AND EVENING WITH GUSTY WINDS
IN EXCESS OF 35 KNOTS WILL REMAIN THE PRIMARY BOATING THREAT.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
IMPACT WX/RADAR.......LASCODY
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
920 AM EDT SUN AUG 10 2014
.UPDATE (REST OF TODAY THROUGH MONDAY)...
13Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUE TO SHOW THE MAIN BAND
OF WESTERLIES LOCATED WELL TO OUR NORTH THIS MORNING AS A WEAK AND
NARROW BAND OF MID/UPPER LEVEL RIDGING EXTENDS FROM EAST OF THE
BAHAMAS OVER THE CENTRAL/NORTHERN FL PENINSULA AND INTO THE GULF OF
MEXICO. LARGEST AMPLITUDE TROUGH WITHIN THE NORTHERN STREAM FLOW
CONTINUES TO PULL EAST OF NEW ENGLAND THIS MORNING WITH THE ONLY
OTHER SIGNIFICANT ENERGY OVER THE CONUS BEING A SHORTWAVE
PROGRESSING ACROSS THE NORTHERN PLAINS AND BRINGING A FEW ROUNDS OF
SHOWERS/STORMS TO THE UPPER MIDWEST/CENTRAL PLAINS.
THE HIGH LEVEL VORTICITY CENTER/CLOSED LOW THAT WAS ILL-DEFINED OVER
THE SOUTHERN BAHAMAS ON SATURDAY IS NOW A BIT MORE VISIBLE IN WV
IMAGERY AS IT SLIDES WESTWARD THROUGH THE FLORIDA STRAITS. THIS
FEATURE IS MOST DEFINED ABOVE 500MB...AND NWP GUIDANCE HAS NOT
CHANGED IN KEEPING THIS ENERGY ON A PROGRESSIVE WESTWARD TRACK INTO
THE SE GOMEX BY MONDAY. SOME DRIER AIR ON THE WESTERN/NORTHERN
PERIPHERY OF THE CIRCULATION HAS WORKED ITS WAY INTO THE SOUTHERN FL
PENINSULA...BUT WILL GENERALLY STAY TO OUR SOUTH/SE DURING THE
DIURNAL CONVECTIVE CYCLE TODAY. SOME INDICATIONS THAT SOME OF THIS
DRIER AIR WILL COME FURTHER NORTH EARLY IN THE WEEK...BUT THE DEGREE
OF DRY AIR DOES NOT APPEAR TO BE ENOUGH TO HAVE ANY SIGNIFICANT
IMPACT ON THE CONVECTIVE FAVORABILITY OF THE ATMOSPHERIC COLUMN.
10/12Z KTBW SOUNDING PROFILE IS SIMILAR (PERHAPS A TAD MORE MOIST)
THAN WE SAW ON SATURDAY. PW VALUES ARE AROUND 1.9"...STILL ABOVE
NORMAL...BUT NOT UNUSUAL FOR THE MIDDLE OF AUGUST. LAPSE RATES AGAIN
ARE ON THE POOR SIDE...AND HAVE SEEN TEMPERATURES ACTUALLY WARM A
DEGREE OR 2 IN THE MIDDLE TO UPPER LEVELS OF THE COLUMN DURING THE
PAST 24 HOURS. 500MB TEMPS WAS MEASURED -6C...WITH IS FAIRLY WARM.
IN ADDITION...THE FREEZING LEVEL IS NEAR 15KFT...AND WET BULB ZERO
NEAR 14KFT. THESE VALUES DO NOT SUGGEST MUCH IN THE WAY OF HAIL IS
LIKELY EITHER. SO THERE ARE ALL THE NEGATIVES FOR STRONGER
UPDRAFTS...HOWEVER...THE COLUMN IS NOT UNFAVORABLE FOR GENERAL
THUNDERSTORM ACTIVITY. THETA-E VALUES IN THE LOWER/MID LEVELS ARE
GENERALLY IN THE UPPER 320S TO LOWER 330S. THESE VALUES ARE NEAR OR
JUST ABOVE CLIMO FOR THIS TIME OF YEAR...AND SHOULD NOT PRESENT ANY
ENTRAINMENT ISSUES FOR GROWING CONVECTIVE COLUMNS. THEREFORE...
SIMILAR TO SATURDAY...THE THREAT FOR SEVERE PULSE STORMS IS NOT
ZERO...BUT IS RATHER LOW. "RUN OF THE MILL" SUMMER STRENGTH STORMS
APPEAR TO BE NORM.
WELL...THE AREA OF SHALLOW CONVECTION OVER THE EASTERN GULF IS WHERE
WE EXPECTED IT TO BE THIS MORNING (SARASOTA NORTHWARD)...HOWEVER THE
COVERAGE IS A BIT LESS THAN MOST OF THE NWP GUIDANCE MEMBERS WOULD
HAVE SUGGESTED 24 HOURS AGO. SURFACE ANALYSIS SHOWS THAT THE
EXPECTED CONVERGENCE BAND DID SET UP...WITH THAT THE MODELS WERE
A TAD AGGRESSIVE WITH THE STRENGTH OF THE CONVERGENCE...AND THAT
EXPLAINS THE LOWER COVERAGE. EITHER WAY...WILL CONTINUE TO SEE A SCT
OF SHOWERS MOVING TOWARD SHORE OVER THIS FAVORED REGION THE NEXT
SEVERAL HOURS.
SUBTROPICAL RIDGE AXIS IS SUPPRESSED JUST TO THE SOUTH OF FORT MYERS
BY A COMPLEX FRONTAL SYSTEM OVER THE SOUTHEAST CONUS. THIS
CONFIGURATION IS SUPPLYING A 1000-700MB MEAN SYNOPTIC FLOW FROM THE
SW (MOST DEFINED NORTH OF TAMPA IN LESS PROXIMITY TO THE RIDGE
AXIS). WOULD EXPECT A CONVECTIVE EVOLUTION PATTERN SIMILAR TO
SATURDAY WITH THIS SETUP AND GENERALLY SIMILAR SOUNDING PROFILE.
CONVECTIVE COVERAGE EXPECTED TO BECOME SCT ALONG AND INSIDE THE I-75
BY MIDDAY INTO THE EARLY AFTERNOON...WITH STORMS QUICKLY
MIGRATING/DEVELOPING INLAND BY THE SECOND HALF OF THE AFTERNOON.
HAVE LOW RAIN CHANCES INSIDE THE I-75 CORRIDOR AFTER 19Z THIS
AFTERNOON...AND THIS CONVECTIVE CLEARING LINE IS LIKELY TO MAKE EVEN
MORE INLAND PENETRATION DURING THE LATER AFTERNOON HOURS. HIGHEST
POPS BY 20Z SHOULD MOST CERTAINLY BE WELL INLAND. HIGH TEMPERATURES
THIS AFTERNOON INTO THE LOWER 90S INLAND AND UPPER 80S TO AROUND 90
AT THE BEACHES.
EVENING STORMS OVER THE INTERIOR DISSIPATE WITH THE LOSS OF DIURNAL
HEATING AND BOUNDARY FOCUS WITHIN A COUPLE HOURS OF SUNSET. A MOSTLY
DRY AND SEASONABLE OVERNIGHT WILL FOLLOW. LATE AT NIGHT...THE SW
FLOW (AS CLIMO WOULD SUGGEST) SHOULD BEGIN TO BUBBLE UP SHALLOW
CONVECTION OVER THE EASTERN GULF OF MEXICO...WITH THE SHOWERS
MIGRATING TO THE COAST BY DAWN. THE SW FLOW AND SOME ADDED FOCUS
CLOSER TO THE FRONT TO OUR NORTH WOULD SUGGEST BEST CHANCE FOR
SHOWERS TO REACH THE COAST WOULD BE TO THE NORTH OF TAMPA BAY.
HOWEVER...WILL KEEP SLIGHT CHANCE POPS FROM PINELLAS COUNTY
SOUTHWARD JUST IN CASE A WEAK LAND BREEZE CAN DEVELOP WITHIN THE
WEAKER GRADIENT NEAR THE RIDGE AXIS AND SET UP A BRIEF WINDOW OF
COASTAL CONVERGENCE AROUND SUNRISE.
TUESDAY...OVERALL LOOKS AS THOUGH WE WILL REPEAT THE FORECAST
PATTERN ONCE AGAIN WITH THE SUBTROPICAL RIDGE STILL IN THE SAME
GENERAL LOCATION. SW FLOW BRINGS A FEW STORMS TO COASTAL AREAS
THROUGH EARLY AFTERNOON...AND THEN PROGRESSES THE MAIN CONVECTIVE
ACTION INLAND. WILL HAVE TO TAKE A CLOSER LOOK AT THE POTENTIAL FOR
SOME DRIER AIR ALOFT...ESPECIALLY SOUTH OF THE I-4 CORRIDOR WITH THE
AFTERNOON FORECAST PACKAGE...HOWEVER AS MENTIONED ABOVE...AT THE
PRESENT TIME...IT DOES NOT APPEAR TO BE A DRY/DEEP ENOUGH TO BE A
BIG NEGATIVE INFLUENCE ON THE DIURNAL CONVECTION. HAVE A GREAT REST
OF YOUR SUNDAY EVERYONE!
&&
.AVIATION...
VFR CONDITIONS PREVAIL ACROSS WEST-CENTRAL AND SOUTHWEST FLORIDA
THIS MORNING. AS IS TYPICAL WITH WESTERLY FLOW...WIDELY SCT SHOWERS
ARE MIGRATING ONSHORE FROM THE GULF AND ANY OF THE COASTAL TERMINALS
MAY SEE A BRIEF SHOWER OVER THE NEXT SEVERAL HOURS. TOWARD
MIDDAY...COVERAGE WILL INCREASE FOR A BRIEF PERIOD OF TIME INTO THE
EARLY AFTERNOON ALONG AND WEST OF THE I-75 CORRIDOR...AND THIS WILL
BE THE BEST CHANCE FOR MOST OF THE TERMINALS TO SEE A STORM PASSAGE.
THEREAFTER...MUCH OF THE CONVECTIVE ACTIVITY WILL MOVE INLAND FROM
I-75...WITH KLAL THE MOST LIKELY PLACE TO SEE A BRIEF STORM AFTER
19Z. STORMS WILL FADE QUICKLY WITH SUNSET OVER THE INTERIOR THIS
EVENING WITH GENERAL VFR CONDITIONS CONTINUING TO PREVAIL INTO THE
OVERNIGHT.
&&
.MARINE...
THE SUBTROPICAL RIDGE AXIS WILL BE ALIGNED ACROSS SOUTH-CENTRAL
FLORIDA THROUGH THE START OF THE WEEK KEEPING WINDS AND SEAS LOW.
SHOWERS AND THUNDERSTORMS WILL DEVELOP DURING THE OVERNIGHT AND
EARLY MORNING HOURS OVER THE GULF AND NEAR-SHORE WATERS...
ESPECIALLY FROM TAMPA BAY NORTHWARD ALONG THE NATURE COAST. THIS
ACTIVITY WILL FAVOR THE MORNING HOURS AND THEN SHIFT INLAND EACH
AFTERNOON. THE AFTERNOON AND EVENING SEA BREEZE WILL INCREASE WINDS
TO AROUND 10 KNOTS ALONG THE COASTAL AREAS. ONLY HAZARDS WILL BE
ISOLATED WATERSPOUTS...LIGHTNING...AND LOCALIZED GUSTY WINDS IN AND
NEAR THUNDERSTORMS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 92 79 92 78 / 40 20 20 20
FMY 94 77 93 77 / 30 10 40 20
GIF 94 75 93 76 / 50 20 40 10
SRQ 91 77 91 77 / 40 20 20 20
BKV 92 73 92 73 / 40 20 40 20
SPG 91 80 91 80 / 40 20 20 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION/MARINE...MROCZKA
FORECAST DISCUSSION BELOW.
20
PREVIOUS LONG TERM DISCUSSION /TUESDAY NIGHT THROUGH SUNDAY/...
CLOSED UPPER LOW SPINNING OVER THE NORTHEAST STATES SHOULD KEEP A
BROAD TROUGH OVER THE EASTERN STATES THROUGH MUCH OF THE
PERIOD...WITH GEORGIA REMAINING UNDER A NORTHWEST UPPER FLOW.
MODELS PERSIST WITH A DRYING TREND FOR WEDNESDAY INTO FRIDAY SO
HAVE CONTINUED WITH NO POPS NORTH FOR THAT PERIOD. STILL LOOKING
FOR SOME BELOW NORMAL TEMPERATURES...ESPECIALLY OVERNIGHT FOR THE
MIDDLE OF THE WEEK. AS FRONTAL BOUNDARY SINKS SOUTH...SOME
CONVECTION POSSIBLE NEAR THE BOUNDARY IN CENTRAL GEORGIA. BY THE
END OF THE LONG TERM...MODELS SHOWING SOME INCREASE IN MOISTURE SO
HAVE INTRODUCED CHANCE POPS BACK ACROSS THE FORECAST AREA.
41
AVIATION...
00Z UPDATE...
THUNDERSTORM ACTIVITY HAS DWINDLED THIS EVENING...BUT SHOWERS WILL
LINGER FOR THE NEXT SEVERAL HOURS. LATEST RUNS OF THE HRRR WEAKEN
THE ACTIVITY ACROSS S TN/N GA...SO WILL LEAVE OUT MENTION IN THE
TAF FOR NOW. AIRMASS HAS NOT CHANGED MUCH FROM PREVIOUS DAYS SO
ALSO EXPECT LOW CLOUDS TO DEVELOP. KEPT TEMPO WORDING FOR SHRA/TSRA
FOR TUESDAY.
//ATL CONFIDENCE...00Z UPDATE...
HIGH CONFIDENCE THAT LOW CIGS WILL DEVELOP...MEDIUM CONFIDENCE ON
CIG HEIGHT. HIGH CONFIDENCE REMAINING ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 72 89 70 89 / 40 40 30 10
ATLANTA 72 87 69 88 / 40 40 30 10
BLAIRSVILLE 68 82 63 80 / 60 40 30 5
CARTERSVILLE 71 86 66 87 / 50 40 30 10
COLUMBUS 74 90 73 91 / 40 40 30 30
GAINESVILLE 71 86 68 87 / 40 40 30 10
MACON 73 90 72 93 / 40 50 40 30
ROME 71 87 65 88 / 60 40 20 10
PEACHTREE CITY 72 88 68 88 / 40 40 30 10
VIDALIA 74 93 74 93 / 40 60 50 40
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
721 AM EDT SUN AUG 10 2014
...ANOTHER ROUND OF DANGEROUS FLASH FLOODING AND COASTAL FLOODING
POSSIBLE THOUGH TONIGHT...
.SYNOPSIS...
A STATIONARY FRONT WITH UNSETTLED WEATHER WILL REMAIN OVER OR
NEAR THE AREA INTO MONDAY...THEN BECOME ILL-DEFINED DURING THE
MIDDLE THE WEEK. A COLD FRONT MAY THEN CROSS THE REGION BY LATE
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO MAJOR CHANGES WERE MADE FOR THE SUNRISE UPDATE. HIGH RES MODELS
STILL SHOW A SIG HVY RAIN EVENT FOR THE AREA TDA. THE GOING FCST
LOOKS GOOD.
A PESKY STNRY FNT WAS PSND ACROSS THE SRN PEE DEE AND SRN MIDLANDS
ERLY THIS MRNG PER 10/06Z SFC ANALYSIS...ESSENTIALLY BISECTING
PARTS OF BERKELEY AND UPR CHARLESTON COUNTIES. THE FNT CONTS TO BE
A FOCUS FOR SHWRS/TSTMS THIS MRNG...MAINLY ACROSS THE MIDLANDS AND
UPSTATE WHERE APRCHG SHORTWAVE ENERGY IS ENHANCING UVV/S IN THAT
AREA. 10/00Z MODEL DATA SUPPORT ANOTHER VRY BUSY DAY FOR THE FCST
AREA WITH VRY HIGH PWATS RUNNING 120 PCNT OF NORMAL INTERACTING
WITH THE SAID FNT AND WAVES OF UPSTREAM VORTICITY TO PRODUCE
ANOTHER ROUND OF WDSPRD SHWRS/TSTMS. RAP WND PROFILES FAVOR BACK-
BUILDING/CONVECTIVE TRAINING BEHAVIOR AGAIN TDA WITH VRY LGT
925-700 HPA WND FIELDS IN PLACE COINCIDENT WITH A SYNOPTIC
ENVIRON SUPPORTING EFFICIENT RNFL. THE RISK FOR BACK-BUILDING WL
BE ENHANCED ALONG THE FNT ITSELF AS IT DRAFTS S AS WELL AS
ALONG ANY MESOSCALE BNDRY COLLISIONS SUCH AS THE SEA BREEZE AND
CONVECTIVE OUTFLOWS. DATA ALSO SUGGEST A WK WAVE OF LOW PRES COULD
FORM ALONG THE SYNOPTIC BNDRY LTR THIS MRNG...WHICH WL FURTHER
INCR LOW-LVL CONVG ACROSS THE RGN. ALL OF THESE FACTORS WL SUPPORT
AN INCRD RISK FOR FLASH FLOODING ACROSS SRN SC AND SE GA AND A
FLASH FLOOD WATCH WL BE ISSUED THROUGH LTE TNGT FOR THE ENTIRE
FCST AREA PER WFO/NCEP COORDINATION. SIMILAR TO YDA...AN ISOLD
STG/SVR TSTM CAN TO BE COMPLETELY RULED OUT WITH CONDS FAVORING
MARGINALLY SVR WET MICROBURSTS. SEE THE HYDROLOGY SECTION BELOW
FOR ADDITIONAL INFO ON THE POTENTIAL FOR FLASH FLOODING AND QPF
AMOUNTS.
GENERALLY USED A BLEND OF THE LATEST NSSL 4KM-WRF AND THE
LATEST HIGH RES ARW TO CONSTRUCT POPS/TIMING OF THE HEAVIEST RAINS
THIS AFTN AS THESE MODELS HAVE PERFORMED THE BEST OVR THE PAST FEW
DAYS. PLAN TO RAISE POPS TO 70-100 PCNT FOR ALL ZONES TDA WITH
THE HIGHEST GRIDDED POPS SLOWLY SINKING S THROUGH THE AFTN PER
SHORT TERM MODEL TRENDS. THERE MAY BE ENOUGH INSOLATION THIS MRNG
TO BOOST TEMPS QUICKLY AFTER SUNRISE WITH HIGHS GENERALLY TOPPING
OUT IN THE UPR 80S N TO LWR 90S S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
TONIGHT...WDSPRD SHWRS/TSTMS WL BE ONGOING AFTER SUNSET WITH HIGH
RES GUIDANCE SUGGESTING A LARGE CONVECTIVE CLUSTER COULD MOVE S
OUT OF SRN SC INTO COASTAL SE GA. THIS IS CONCERNING AS THIS COULD
IMPACT THE SAV METRO AREA DURING ALREADY HIGH ASTRONOMICAL
TIDES...THUS ENHANCING THE RISK FOR SIG FLASH FLOODING. ADJUSTED
GRIDDED POPS TO SHOW THE HIGHEST POPS ACROSS THE S WITH HIGHER
POPS SHIFTING BACK N OVRNGT BACK NEAR THE VCNTY OF THE STNRY FNT...
WHICH SHOULD BE LOCATED ACROSS SRN SC. IT WL CONT BE QUITE MUGGY
WITH LOWS IN THE THE MID-UPR 70S.
MONDAY...THE DAY WILL BEGIN WITH LITTLE OVERALL CHANGE IN THE
PATTERN AT THE SURFACE AND ALOFT. A NEARLY STATIONARY FRONT WILL
LINGER OVER THE SOUTH CAROLINA ZONES...WHILE A FAIRLY WEAK TROUGH
PATTERN PREVAILS ALOFT. SHORTWAVE ENERGY FAR TO THE NORTH...DIVING
INTO THE GREAT LAKES AND OHIO VALLEY REGIONS...WILL EXTEND THE
UPPER TROUGH DOWN TOWARD THE EAST COAST LATE IN THE DAY. A WAVE OF
SURFACE LOW PRESSURE WILL TAKE SHAPE ALONG THE MEANDERING FRONT IN
RESPONSE TO THE GRADUALLY AMPLIFYING PATTERN...EVENTUALLY SHIFTING
NORTHEAST UP THE CAROLINA COASTLINE DOWNSTREAM OF THE TROUGH AXIS
OVERNIGHT. THE CONTINUED PRESENCE OF THE BOUNDARY AND SURFACE WAVE
WILL PROVIDE PERSISTENT FORCING FOR ASCENT...AND WHEN COMBINED
WITH SHORTWAVE ENERGY PROGRESSING THROUGH THE REGION...WILL
MAINTAIN DEEP MOISTURE ACROSS THE SOUTHEAST STATES. NUMERICAL
MODELS ARE IN GOOD AGREEMENT INDICATING SCATTERED TO NUMEROUS
THUNDERSTORM DEVELOPMENT DURING THE DAYTIME HOURS...BEFORE
PRECIPITATION COVERAGE DIMINISHES FROM WEST TO EAST OVERNIGHT.
PRECIPITABLE WATER VALUES WILL STILL BE ABOVE 2.25 INCHES ACROSS
THE FORECAST AREA MONDAY AFTERNOON...AND WITH STORM MOTIONS
LESS THAN 10 KT...HEAVY DOWNPOURS AND LOCALIZED FLOODING AGAIN
APPEARS POSSIBLE. THICK CLOUD COVER AND DECENT RAIN COVERAGE WILL
KEEP HIGH TEMPERATURES NEAR OR JUST A DEGREE BELOW SEASONAL
NORMALS...RANGING FROM AROUND 89 DEGREES NORTH TO 92 SOUTH TO THE
ALTAMAHA RIVER.
TUESDAY...THE AXIS OF THE AMPLIFYING UPPER TROUGH WILL EXTEND DOWN
THE EAST COAST...WITH ASSOCIATED SHORTWAVE ENERGY PICKING UP THE
SURFACE LOW AND DRIVING IT NORTHEAST AND OFF THE MID ATLANTIC
COAST BY THE NIGHTTIME HOURS. SUFFICIENT DEEP MOISTURE AND
CONVERGENCE FROM THE SYNOPTIC SCALE FEATURES WILL PROVIDE THE
NECESSARY INGREDIENTS TO ONCE AGAIN SUPPORT RAIN CHANCES IN THE 50
PERCENT RANGE...ESPECIALLY ALONG AND TO THE SOUTH OF THE
TRAILING/WEAK FRONT. STORM MOTIONS ARE NOTABLY FASTER THAN THE
PREVIOUS DAY...HOWEVER PRECIPITABLE WATER VALUES WILL STILL BE
ABOVE 2.0 INCHES. THUS...HEAVY DOWNPOURS AND ISOLATED LOCALIZED
FLOODING ARE STILL POSSIBLE...ESPECIALLY WHERE BOUNDARY
INTERACTIONS OCCUR. TEMPERATURES WILL REACH THE LOWER 90S AWAY
FROM THE LOCALLY COOLER COASTLINE UNDER MOSTLY CLOUDY SKIES. BEST
SHOWER/THUNDERSTORM COVERAGE WILL SHIFT TO THE COASTAL AREAS AND
NEARBY WATERS OVERNIGHT.
WEDNESDAY...THE STRENGTHENING SURFACE LOW WILL HAVE LIFTED WELL TO
THE NORTHEAST OF THE AREA BY MID WEEK...WITH A DIFFUSE BOUNDARY
AND SURFACE TROUGH LINGERING ALONG THE COAST IN ITS WAKE. DRIER
HIGH PRESSURE WILL STRUGGLE TO MAKE SIGNIFICANT PROGRESS TOWARD
THE SOUTHEAST COAST FROM THE OHIO AND TENNESSEE VALLEYS...ALLOWING
A REMNANT BAND OF THE DEEP MOISTURE TO PERSIST ACROSS COASTAL AND
SOUTHERN COUNTIES. WILL TREND RAIN CHANCES DOWNWARD COMPARED TO
PREVIOUS DAYS DUE TO THE WEAKENING SYNOPTIC FEATURES...YET
MAINTAIN SOLID CHANCE POPS IN THE 30 TO 40 PERCENT RANGE DURING
THE DAYTIME HOURS. AS WITH PREVIOUS DAYS...THUNDERSTORM COVERAGE
WILL DIMINISH FROM WEST TO EAST DURING THE EVENING AND NIGHTTIME
PERIODS. HIGH TEMPERATURES WILL REACH THE LOWER 90S
INLAND...WITHIN A DEGREE OR TWO OF SEASONAL NORMALS FOR EARLY/MID
AUGUST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
THE FORECAST AREA WILL GENERALLY REMAIN BETWEEN A BROAD UPPER
TROUGH STRETCHING DOWN MUCH OF THE EASTERN UNITED STATES AND AN
UPPER RIDGE SUPPRESSED WELL TO THE SOUTH OVER FLORIDA AND
EVENTUALLY THE GULF OF MEXICO. A MORE WELL-DEFINED COLD FRONT
REPRESENTING THE LEADING EDGE OF DRIER HIGH PRESSURE WILL SHIFT
TOWARD THE SOUTHEAST STATES BY THURSDAY...POSSIBLY STALLING TO THE
EAST/SOUTHEAST FRIDAY. ALTHOUGH THE SURFACE HIGH WILL BE WEAKENING
AS IT SHIFTS INTO THE AREA LATE THIS WEEK...EXPECT IT TO PROVIDE
SUFFICIENT DRIER AIR TO SUPPORT A MORE SEASONAL CONVECTIVE
COVERAGE SCENARIO THROUGH THE WEEKEND. HAVE THUS INDICATED RAIN
CHANCES BACK TO THE SLIGHT CHANCE TO LOW CHANCE RANGE DURING THE
CLIMATOLOGICALLY FAVORED AFTERNOON HOURS EACH DAY FROM THURSDAY
THROUGH SUNDAY. DEWPOINTS WILL DECREASE A BIT DURING THE EXTENDED
PERIOD...HOWEVER THERE WILL BE LITTLE NOTABLE CHANGE IN THE
OVERALL HIGH TEMPERATURE RANGE. TEMPERATURES WILL PEAK IN THE
LOWER 90S INLAND EACH AFTERNOON.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
IT WL BE ANOTHER ACTIVE DAY FOR SHWRS/TSTMS ACROSS THE RGN. BOTH
KCHS AND KSAV HAVE HIGH PROBABILITIES FOR TSTM IMPACTS THIS AFTN.
WL CALL FOR PREVAILING MVFR TSRA AT KCHS BY 18Z AND 20Z AT KSAV
WITH TEMPO CONDITIONS MARGINAL IFR FOR MAINLY HVY RAIN. CURRENT
THINKING IS THAT TSTMS WL PUSH INLAND FROM THE TERMINALS BY
SUNSET...BUT COULD LINGER AT KSAV A BIT LONGER IF THE LATEST NSSL
WRF VERIFIES.
EXTENDED AVIATION OUTLOOK...EXPECT SCATTERED AND MAINLY DIURNAL
SHOWERS AND THUNDERSTORMS...WITH BRIEF PERIODS OF FLIGHT
RESTRICTIONS THROUGH THURSDAY.
&&
.MARINE...
TODAY AND TONIGHT...LGT WND FIELDS WL PERSIST AS A STNRY FNT CONTS
TO MEANDER ACROSS THE SC WTRS. SLGTLY HIGHER WNDS WL BE FOUND
ACROSS THE GA WTRS...BUT BOTH WNDS AND SEAS WL REMAIN WELL BLO ANY
ADV THRESHOLDS. A FEW STG TSTMS WL BE PSBL THROUGH TNGT WHICH MAY
REQUIRE SPECIAL MARINE WRNGS. THIS WL BE ADDRESSED IN THE
HAZARDOUS WX OTLK.
MONDAY AND TUESDAY...A MEANDERING WEAK FRONT WILL PERSIST OVER OR
NEAR THE MARINE ZONES THROUGH THE EARLY WEEK PERIOD...AS A WAVE OF
LOW PRESSURE LIFTS TO THE NORTHEAST AND OFF THE MID ATLANTIC
COAST. EXPECT WIND SPEEDS TO REMAIN 15 KT OR LESS AND SEAS
GENERALLY 2 TO 4 FT. SCATTERED TO NUMEROUS THUNDERSTORMS ARE
POSSIBLE EACH DAY...AND SOME STORMS THAT DEVELOP OR MOVE OFFSHORE
FROM LAND AREAS COULD BECOME STRONG ENOUGH TO PRODUCE WINDS IN
EXCESS OF 30 OR 40 KT...HEAVY RAIN AND FREQUENT LIGHTNING. MARINE
WEATHER STATEMENTS AND/OR SPECIAL MARINE WARNINGS MAY BECOME
NECESSARY AT TIMES.
WEDNESDAY THROUGH THURSDAY...THE STATIONARY FRONT BECOMES DIFFUSE
BY MID WEEK AHEAD OF A COLD FRONT BY LATE IN THE PERIOD. THERE
WILL BE SOME TIGHTENING OF THE GRADIENT BETWEEN THE UPSTREAM FRONT
AND THE SUB-TROPICAL ATLANTIC RIDGE TO THE SOUTH/SOUTHEAST...YET
MARINE CONDITIONS WILL REMAIN BELOW ANY ADVISORY HEADLINES.
STRONGER THUNDERSTORMS WILL AGAIN PERIODICALLY OCCUR...ALTHOUGH
PERHAPS WITH LESS FREQUENCY THAN EARLIER IN THE WEEK.
&&
.HYDROLOGY...
AS NOTED IN THE SHORT TERM SECTION ABV...SYNOPTIC AND MESOSCALE
ATMOSPHERIC CONDS FAVOR ANOTHER ROUND OF HVY RNFL THROUGH TNGT.
MANY AREAS...ESP ACROSS THE CHARLESTON TRI-COUNTY AREA...SAW
UPWARDS OF 2-4 INCHES WITH ISOLD AMOUNTS OF 6-10 INCHES WITH
SIGNIFICANT FLASH FLOODING NOTED IN DWTN CHARLESTON PRIOR TO THE
ONSET OF HIGH ASTRONOMICAL TIDES. SIGNIFICANT URBAN FLOODING WAS
ALSO OBSERVED IN THE BEAUFORT AND SAVANNAH METRO AREAS AS WELL.
WITH GROUNDS ALREADY SATURATED FROM RECENT HVY RAINS...1-HR AND
3-HR FLASH FLOOD GUIDANCE VALUES HAVE DROPPED CONSIDERABLY OVER
THE PAST 24 HRS. WITH THE ENVIRON SUPPORTIVE OF EFFICIENT
RNFL...THESE VALUES COULD BE EASILY SURPASSED WHERE THE HEAVIER
CONVECTIVE CONGLOMERATES FORM. COMPLICATING MATTERS IS THAT SOME
OF THE HIGH RES MODELS SUGGEST TSTMS WITH TORRENTIAL RAINS COULD
FALL PRIOR TO AND/OR DURING HIGH TIDE...WHERE TIDE LEVELS ARE
ALREADY RUNNING VRY HIGH DUE TO ASTRONOMICAL INFLUENCES. THIS WL
RESULT IN AN ENHANCED RISK FOR FLASH FLOODING ACROSS THE COASTAL
COUNTIES AND ESPECIALLY IN THE CHARLESTON AND SAVANNAH METRO
AREAS. XPCT GENERAL RNFL AMOUNTS OF 2-4 INCHES THROUGH TNGT WITH
ISOLD AMOUNTS POTENTIALLY EXCEEDING 6-8 INCHES.
&&
.TIDES/COASTAL FLOODING...
ANOTHER ROUND OF COASTAL FLOODING IS LIKELY AGAIN TNGT. CURRENT
AND FCST TIDAL DEPARTURES SUGGEST TIDE LEVELS WL BREACH MODERATE
FLOOD THRESHOLDS ALONG THE LWR SC COAST AND SHALLOW COASTAL
FLOODING THRESHOLDS FOR THE UPR GA COAST. XPCT TIDES OF 7.4-7.7 FT
MLLW IN THE CHARLESTON HARBOR WITH 9.2 TO 9.5 FT MLLW AT FT
PULASKI. SIMILAR TO SATURDAY...HVY RAINS COULD FALL AROUND/NEAR
THE TIME OF HIGH TIDE WHICH WL ONLY EXACERBATE ENHANCE THE FLOOD
IMPACT. A COASTAL FLOOD ADV WL BE ISSUED FOR ALL COASTAL ZONES...
INCLUDING TIDAL BERKELEY...FROM 7PM-MIDNIGHT.
THE PROXIGEAN SPRING TIDE WILL OCCUR TDA AND THESE ASTRONOMICAL
INFLUENCES WILL CONTINUE TO GENERATE ELEVATED TIDES INTO EARLY
THIS WEEK. SINCE ONLY SMALL DEPARTURES ARE NEEDED ABOVE THE
PREDICTED ASTRONOMICAL TIDE VALUES TO RESULT IN AT LEAST SHALLOW
COASTAL FLOODING...THIS WILL LIKELY BOOST TIDE LEVELS ABOVE
CRITICAL THRESHOLDS THROUGH MONDAY OR TUESDAY. THE BEST CHANCE FOR
COASTAL FLOOD ADVISORIES WOULD BE DURING THE EVENING HIGH TIDES.
SHOULD HEAVY RAIN OCCUR AROUND THE TIMES OF THE ELEVATED HIGH
TIDES...RUNOFF WILL BE INHIBITED AND MORE SIGNIFICANT FLOODING
COULD OCCUR WITHIN COASTAL COMMUNITIES.
&&
.EQUIPMENT...
THE CHARLESTON SC WSR-88D /KCLX/ REMAINS OUT OF SERVICE DUE TO A
SIGNIFICANT MECHANICAL FAILURE. THE CURRENT ESTIMATE HAS THE RADAR
RETURNING TO SERVICE BETWEEN AUGUST 21 AND 25.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR GAZ087-088-099>101-
114>119-137>141.
COASTAL FLOOD ADVISORY FROM 7 PM THIS EVENING TO MIDNIGHT EDT
TONIGHT FOR GAZ117-119-139-141.
SC...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR SCZ040-042>045-
047>052.
COASTAL FLOOD ADVISORY FROM 7 PM THIS EVENING TO MIDNIGHT EDT
TONIGHT FOR SCZ048>052.
MARINE...NONE.
&&
$$
ST/WMS
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
359 AM EDT SUN AUG 10 2014
...ANOTHER ROUND OF DANGEROUS FLASH FLOODING AND COASTAL FLOODING
POSSIBLE THOUGH TONIGHT...
.SYNOPSIS...
A STATIONARY FRONT WITH UNSETTLED WEATHER WILL REMAIN OVER OR
NEAR THE AREA INTO MONDAY...THEN BECOME ILL-DEFINED DURING THE
MIDDLE THE WEEK. A COLD FRONT MAY THEN CROSS THE REGION BY LATE
WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
A PESKY STNRY FNT WAS PSND ACROSS THE SRN PEE DEE AND SRN MIDLANDS
ERLY THIS MRNG PER 10/06Z SFC ANALYSIS...ESSENTIALLY BISECTING
PARTS OF BERKELEY AND UPR CHARLESTON COUNTIES. THE FNT CONTS TO BE
A FOCUS FOR SHWRS/TSTMS THIS MRNG...MAINLY ACROSS THE MIDLANDS AND
UPSTATE WHERE APRCHG SHORTWAVE ENERGY IS ENHANCING UVV/S IN THAT
AREA. 10/00Z MODEL DATA SUPPORT ANOTHER VRY BUSY DAY FOR THE FCST
AREA WITH VRY HIGH PWATS RUNNING 120 PCNT OF NORMAL INTERACTING
WITH THE SAID FNT AND WAVES OF UPSTREAM VORTICITY TO PRODUCE
ANOTHER ROUND OF WDSPRD SHWRS/TSTMS. RAP WND PROFILES FAVOR BACK-
BUILDING/CONVECTIVE TRAINING BEHAVIOR AGAIN TDA WITH VRY LGT
925-700 HPA WND FIELDS IN PLACE COINCIDENT WITH A SYNOPTIC
ENVIRON SUPPORTING EFFICIENT RNFL. THE RISK FOR BACK-BUILDING WL
BE ENHANCED ALONG THE FNT ITSELF AS IT DRAFTS S AS WELL AS
ALONG ANY MESOSCALE BNDRY COLLISIONS SUCH AS THE SEA BREEZE AND
CONVECTIVE OUTFLOWS. DATA ALSO SUGGEST A WK WAVE OF LOW PRES COULD
FORM ALONG THE SYNOPTIC BNDRY LTR THIS MRNG...WHICH WL FURTHER
INCR LOW-LVL CONVG ACROSS THE RGN. ALL OF THESE FACTORS WL SUPPORT
AN INCRD RISK FOR FLASH FLOODING ACROSS SRN SC AND SE GA AND A
FLASH FLOOD WATCH WL BE ISSUED THROUGH LTE TNGT FOR THE ENTIRE
FCST AREA PER WFO/NCEP COORDINATION. SIMILAR TO YDA...AN ISOLD
STG/SVR TSTM CAN TO BE COMPLETELY RULED OUT WITH CONDS FAVORING
MARGINALLY SVR WET MICROBURSTS. SEE THE HYDROLOGY SECTION BELOW
FOR ADDITIONAL INFO ON THE POTENTIAL FOR FLASH FLOODING AND QPF
AMOUNTS.
GENERALLY USED A BLEND OF THE LATEST NSSL 4KM-WRF AND THE
LATEST HIGH RES ARW TO CONSTRUCT POPS/TIMING OF THE HEAVIEST RAINS
THIS AFTN AS THESE MODELS HAVE PERFORMED THE BEST OVR THE PAST FEW
DAYS. PLAN TO RAISE POPS TO 70-100 PCNT FOR ALL ZONES TDA WITH
THE HIGHEST GRIDDED POPS SLOWLY SINKING S THROUGH THE AFTN PER
SHORT TERM MODEL TRENDS. THERE MAY BE ENOUGH INSOLATION THIS MRNG
TO BOOST TEMPS QUICKLY AFTER SUNRISE WITH HIGHS GENERALLY TOPPING
OUT IN THE UPR 80S N TO LWR 90S S.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
TONIGHT...WDSPRD SHWRS/TSTMS WL BE ONGOING AFTER SUNSET WITH HIGH
RES GUIDANCE SUGGESTING A LARGE CONVECTIVE CLUSTER COULD MOVE S
OUT OF SRN SC INTO COASTAL SE GA. THIS IS CONCERNING AS THIS COULD
IMPACT THE SAV METRO AREA DURING ALREADY HIGH ASTRONOMICAL
TIDES...THUS ENHANCING THE RISK FOR SIG FLASH FLOODING. ADJUSTED
GRIDDED POPS TO SHOW THE HIGHEST POPS ACROSS THE S WITH HIGHER
POPS SHIFTING BACK N OVRNGT BACK NEAR THE VCNTY OF THE STNRY FNT...
WHICH SHOULD BE LOCATED ACROSS SRN SC. IT WL CONT BE QUITE MUGGY
WITH LOWS IN THE THE MID-UPR 70S.
MONDAY...THE DAY WILL BEGIN WITH LITTLE OVERALL CHANGE IN THE
PATTERN AT THE SURFACE AND ALOFT. A NEARLY STATIONARY FRONT WILL
LINGER OVER THE SOUTH CAROLINA ZONES...WHILE A FAIRLY WEAK TROUGH
PATTERN PREVAILS ALOFT. SHORTWAVE ENERGY FAR TO THE NORTH...DIVING
INTO THE GREAT LAKES AND OHIO VALLEY REGIONS...WILL EXTEND THE
UPPER TROUGH DOWN TOWARD THE EAST COAST LATE IN THE DAY. A WAVE OF
SURFACE LOW PRESSURE WILL TAKE SHAPE ALONG THE MEANDERING FRONT IN
RESPONSE TO THE GRADUALLY AMPLIFYING PATTERN...EVENTUALLY SHIFTING
NORTHEAST UP THE CAROLINA COASTLINE DOWNSTREAM OF THE TROUGH AXIS
OVERNIGHT. THE CONTINUED PRESENCE OF THE BOUNDARY AND SURFACE WAVE
WILL PROVIDE PERSISTENT FORCING FOR ASCENT...AND WHEN COMBINED
WITH SHORTWAVE ENERGY PROGRESSING THROUGH THE REGION...WILL
MAINTAIN DEEP MOISTURE ACROSS THE SOUTHEAST STATES. NUMERICAL
MODELS ARE IN GOOD AGREEMENT INDICATING SCATTERED TO NUMEROUS
THUNDERSTORM DEVELOPMENT DURING THE DAYTIME HOURS...BEFORE
PRECIPITATION COVERAGE DIMINISHES FROM WEST TO EAST OVERNIGHT.
PRECIPITABLE WATER VALUES WILL STILL BE ABOVE 2.25 INCHES ACROSS
THE FORECAST AREA MONDAY AFTERNOON...AND WITH STORM MOTIONS
LESS THAN 10 KT...HEAVY DOWNPOURS AND LOCALIZED FLOODING AGAIN
APPEARS POSSIBLE. THICK CLOUD COVER AND DECENT RAIN COVERAGE WILL
KEEP HIGH TEMPERATURES NEAR OR JUST A DEGREE BELOW SEASONAL
NORMALS...RANGING FROM AROUND 89 DEGREES NORTH TO 92 SOUTH TO THE
ALTAMAHA RIVER.
TUESDAY...THE AXIS OF THE AMPLIFYING UPPER TROUGH WILL EXTEND DOWN
THE EAST COAST...WITH ASSOCIATED SHORTWAVE ENERGY PICKING UP THE
SURFACE LOW AND DRIVING IT NORTHEAST AND OFF THE MID ATLANTIC
COAST BY THE NIGHTTIME HOURS. SUFFICIENT DEEP MOISTURE AND
CONVERGENCE FROM THE SYNOPTIC SCALE FEATURES WILL PROVIDE THE
NECESSARY INGREDIENTS TO ONCE AGAIN SUPPORT RAIN CHANCES IN THE 50
PERCENT RANGE...ESPECIALLY ALONG AND TO THE SOUTH OF THE
TRAILING/WEAK FRONT. STORM MOTIONS ARE NOTABLY FASTER THAN THE
PREVIOUS DAY...HOWEVER PRECIPITABLE WATER VALUES WILL STILL BE
ABOVE 2.0 INCHES. THUS...HEAVY DOWNPOURS AND ISOLATED LOCALIZED
FLOODING ARE STILL POSSIBLE...ESPECIALLY WHERE BOUNDARY
INTERACTIONS OCCUR. TEMPERATURES WILL REACH THE LOWER 90S AWAY
FROM THE LOCALLY COOLER COASTLINE UNDER MOSTLY CLOUDY SKIES. BEST
SHOWER/THUNDERSTORM COVERAGE WILL SHIFT TO THE COASTAL AREAS AND
NEARBY WATERS OVERNIGHT.
WEDNESDAY...THE STRENGTHENING SURFACE LOW WILL HAVE LIFTED WELL TO
THE NORTHEAST OF THE AREA BY MID WEEK...WITH A DIFFUSE BOUNDARY
AND SURFACE TROUGH LINGERING ALONG THE COAST IN ITS WAKE. DRIER
HIGH PRESSURE WILL STRUGGLE TO MAKE SIGNIFICANT PROGRESS TOWARD
THE SOUTHEAST COAST FROM THE OHIO AND TENNESSEE VALLEYS...ALLOWING
A REMNANT BAND OF THE DEEP MOISTURE TO PERSIST ACROSS COASTAL AND
SOUTHERN COUNTIES. WILL TREND RAIN CHANCES DOWNWARD COMPARED TO
PREVIOUS DAYS DUE TO THE WEAKENING SYNOPTIC FEATURES...YET
MAINTAIN SOLID CHANCE POPS IN THE 30 TO 40 PERCENT RANGE DURING
THE DAYTIME HOURS. AS WITH PREVIOUS DAYS...THUNDERSTORM COVERAGE
WILL DIMINISH FROM WEST TO EAST DURING THE EVENING AND NIGHTTIME
PERIODS. HIGH TEMPERATURES WILL REACH THE LOWER 90S
INLAND...WITHIN A DEGREE OR TWO OF SEASONAL NORMALS FOR EARLY/MID
AUGUST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
THE FORECAST AREA WILL GENERALLY REMAIN BETWEEN A BROAD UPPER
TROUGH STRETCHING DOWN MUCH OF THE EASTERN UNITED STATES AND AN
UPPER RIDGE SUPPRESSED WELL TO THE SOUTH OVER FLORIDA AND
EVENTUALLY THE GULF OF MEXICO. A MORE WELL-DEFINED COLD FRONT
REPRESENTING THE LEADING EDGE OF DRIER HIGH PRESSURE WILL SHIFT
TOWARD THE SOUTHEAST STATES BY THURSDAY...POSSIBLY STALLING TO THE
EAST/SOUTHEAST FRIDAY. ALTHOUGH THE SURFACE HIGH WILL BE WEAKENING
AS IT SHIFTS INTO THE AREA LATE THIS WEEK...EXPECT IT TO PROVIDE
SUFFICIENT DRIER AIR TO SUPPORT A MORE SEASONAL CONVECTIVE
COVERAGE SCENARIO THROUGH THE WEEKEND. HAVE THUS INDICATED RAIN
CHANCES BACK TO THE SLIGHT CHANCE TO LOW CHANCE RANGE DURING THE
CLIMATOLOGICALLY FAVORED AFTERNOON HOURS EACH DAY FROM THURSDAY
THROUGH SUNDAY. DEWPOINTS WILL DECREASE A BIT DURING THE EXTENDED
PERIOD...HOWEVER THERE WILL BE LITTLE NOTABLE CHANGE IN THE
OVERALL HIGH TEMPERATURE RANGE. TEMPERATURES WILL PEAK IN THE
LOWER 90S INLAND EACH AFTERNOON.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
WATCHING FOR PSBL STRATUS BUILD DOWN AT KSAV...BUT THOUGHTS ARE
THAT IFR CIGS WILL NOT BECOME ESTABLISHED. SOME SHALLOW MVFR FOG
PSBL HWVR. NO CONCERNS AT KCHS THROUGH SUNRISE. IT WL BE ANOTHER
ACTIVE DAY FOR SHWRS/TSTMS ACROSS THE RGN. BOTH KCHS AND KSAV HAVE
HIGH PROBABILITIES FOR TSTM IMPACTS THIS AFTN. WL CALL FOR
PREVAILING MVFR TSRA AT KCHS BY 18Z AND 20Z AT KSAV WITH TEMPO
CONDITIONS MARGINAL IFR FOR MAINLY HVY RAIN. CURRENT THINKING IS
THAT TSTMS WL PUSH INLAND FROM THE TERMINALS BY SUNSET...BUT COULD
LINGER AT KSAV A BIT LONGER IF THE LATEST NSSL WRF VERIFIES.
EXTENDED AVIATION OUTLOOK...EXPECT SCATTERED AND MAINLY DIURNAL
SHOWERS AND THUNDERSTORMS...WITH BRIEF PERIODS OF FLIGHT
RESTRICTIONS THROUGH THURSDAY.
&&
.MARINE...
TODAY AND TONIGHT...LGT WND FIELDS WL PERSIST AS A STNRY FNT CONTS
TO MEANDER ACROSS THE SC WTRS. SLGTLY HIGHER WNDS WL BE FOUND
ACROSS THE GA WTRS...BUT BOTH WNDS AND SEAS WL REMAIN WELL BLO ANY
ADV THRESHOLDS. A FEW STG TSTMS WL BE PSBL THROUGH TNGT WHICH MAY
REQUIRE SPECIAL MARINE WRNGS. THIS WL BE ADDRESSED IN THE
HAZARDOUS WX OTLK.
MONDAY AND TUESDAY...A MEANDERING WEAK FRONT WILL PERSIST OVER OR
NEAR THE MARINE ZONES THROUGH THE EARLY WEEK PERIOD...AS A WAVE OF
LOW PRESSURE LIFTS TO THE NORTHEAST AND OFF THE MID ATLANTIC
COAST. EXPECT WIND SPEEDS TO REMAIN 15 KT OR LESS AND SEAS
GENERALLY 2 TO 4 FT. SCATTERED TO NUMEROUS THUNDERSTORMS ARE
POSSIBLE EACH DAY...AND SOME STORMS THAT DEVELOP OR MOVE OFFSHORE
FROM LAND AREAS COULD BECOME STRONG ENOUGH TO PRODUCE WINDS IN
EXCESS OF 30 OR 40 KT...HEAVY RAIN AND FREQUENT LIGHTNING. MARINE
WEATHER STATEMENTS AND/OR SPECIAL MARINE WARNINGS MAY BECOME
NECESSARY AT TIMES. MARINERS SHOULD MAINTAIN A WEATHER
WATCH...LISTENING TO NOAA WEATHER RADIO OR APPROPRIATE VHF
CHANNELS.
WEDNESDAY THROUGH THURSDAY...THE STATIONARY FRONT BECOMES DIFFUSE
BY MID WEEK AHEAD OF A COLD FRONT BY LATE IN THE PERIOD. THERE
WILL BE SOME TIGHTENING OF THE GRADIENT BETWEEN THE UPSTREAM FRONT
AND THE SUB-TROPICAL ATLANTIC RIDGE TO THE SOUTH/SOUTHEAST...YET
MARINE CONDITIONS WILL REMAIN BELOW ANY ADVISORY HEADLINES.
STRONGER THUNDERSTORMS WILL AGAIN PERIODICALLY OCCUR...ALTHOUGH
PERHAPS WITH LESS FREQUENCY THAN EARLIER IN THE WEEK.
&&
.HYDROLOGY...
AS NOTED IN THE SHORT TERM SECTION ABV...SYNOPTIC AND MESOSCALE
ATMOSPHERIC CONDS FAVOR ANOTHER ROUND OF HVY RNFL THROUGH TNGT.
MANY AREAS...ESP ACROSS THE CHARLESTON TRI-COUNTY AREA...SAW
UPWARDS OF 2-4 INCHES WITH ISOLD AMOUNTS OF 6-10 INCHES WITH
SIGNIFICANT FLASH FLOODING NOTED IN DWTN CHARLESTON PRIOR TO THE
ONSET OF HIGH ASTRONOMICAL TIDES. SIGNIFICANT URBAN FLOODING WAS
ALSO OBSERVED IN THE BEAUFORT AND SAVANNAH METRO AREAS AS WELL.
WITH GROUNDS ALREADY SATURATED FROM RECENT HVY RAINS...1-HR AND
3-HR FLASH FLOOD GUIDANCE VALUES HAVE DROPPED CONSIDERABLY OVER
THE PAST 24 HRS. WITH THE ENVIRON SUPPORTIVE OF EFFICIENT
RNFL...THESE VALUES COULD BE EASILY SURPASSED WHERE THE HEAVIER
CONVECTIVE CONGLOMERATES FORM. COMPLICATING MATTERS IS THAT SOME
OF THE HIGH RES MODELS SUGGEST TSTMS WITH TORRENTIAL RAINS COULD
FALL PRIOR TO AND/OR DURING HIGH TIDE...WHERE TIDE LEVELS ARE
ALREADY RUNNING VRY HIGH DUE TO ASTRONOMICAL INFLUENCES. THIS WL
RESULT IN AN ENHANCED RISK FOR FLASH FLOODING ACROSS THE COASTAL
COUNTIES AND ESPECIALLY IN THE CHARLESTON AND SAVANNAH METRO
AREAS. XPCT GENERAL RNFL AMOUNTS OF 2-4 INCHES THROUGH TNGT WITH
ISOLD AMOUNTS POTENTIALLY EXCEEDING 6-8 INCHES.
&&
.TIDES/COASTAL FLOODING...
ANOTHER ROUND OF COASTAL FLOODING IS LIKELY AGAIN TNGT. CURRENT
AND FCST TIDAL DEPARTURES SUGGEST TIDE LEVELS WL BREACH MODERATE
FLOOD THRESHOLDS ALONG THE LWR SC COAST AND SHALLOW COASTAL
FLOODING THRESHOLDS FOR THE UPR GA COAST. XPCT TIDES OF 7.4-7.7 FT
MLLW IN THE CHARLESTON HARBOR WITH 9.2 TO 9.5 FT MLLW AT FT
PULASKI. SIMILAR TO SATURDAY...HVY RAINS COULD FALL AROUND/NEAR
THE TIME OF HIGH TIDE WHICH WL ONLY EXACERBATE ENHANCE THE FLOOD
IMPACT. A COASTAL FLOOD ADV WL BE ISSUED FOR ALL COASTAL ZONES...
INCLUDING TIDAL BERKELEY...FROM 7PM-MIDNIGHT.
THE PROXIGEAN SPRING TIDE WILL OCCUR TDA AND THESE ASTRONOMICAL
INFLUENCES WILL CONTINUE TO GENERATE ELEVATED TIDES INTO EARLY
THIS WEEK. SINCE ONLY SMALL DEPARTURES ARE NEEDED ABOVE THE
PREDICTED ASTRONOMICAL TIDE VALUES TO RESULT IN AT LEAST SHALLOW
COASTAL FLOODING...THIS WILL LIKELY BOOST TIDE LEVELS ABOVE
CRITICAL THRESHOLDS THROUGH MONDAY OR TUESDAY. THE BEST CHANCE FOR
COASTAL FLOOD ADVISORIES WOULD BE DURING THE EVENING HIGH TIDES.
SHOULD HEAVY RAIN OCCUR AROUND THE TIMES OF THE ELEVATED HIGH
TIDES...RUNOFF WILL BE INHIBITED AND MORE SIGNIFICANT FLOODING
COULD OCCUR WITHIN COASTAL COMMUNITIES.
&&
.EQUIPMENT...
THE CHARLESTON SC WSR-88D /KCLX/ REMAINS OUT OF SERVICE DUE TO A
SIGNIFICANT MECHANICAL FAILURE. THE CURRENT ESTIMATE HAS THE RADAR
RETURNING TO SERVICE BETWEEN AUGUST 21 AND 25.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR GAZ087-088-099>101-
114>119-137>141.
COASTAL FLOOD ADVISORY FROM 7 PM THIS EVENING TO MIDNIGHT EDT
TONIGHT FOR GAZ117-119-139-141.
SC...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR SCZ040-042>045-
047>052.
COASTAL FLOOD ADVISORY FROM 7 PM THIS EVENING TO MIDNIGHT EDT
TONIGHT FOR SCZ048>052.
MARINE...NONE.
&&
$$
ST/WMS
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
112 AM EDT SUN AUG 10 2014
.SYNOPSIS...
A NEARLY STATIONARY FRONTAL ZONE WILL REMAIN IN THE FORECAST AREA
THROUGH TUESDAY. THE FRONT WILL BRING NUMEROUS SHOWERS AND
THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
WIDESPREAD SHOWERS WITH ISOLATED THUNDERSTORMS EXPECTED ACROSS THE
MIDLANDS INTO THE EARLY MORNING HOURS. AIR MASS VERY MOIST AND
UNSTABLE WITH PWAT AROUND 2.1 INCHES. CANNOT RULE OUT WEAK UPPER
DISTURBANCE CROSSING THE AREA IN DIFLUENT FLOW ALOFT. BOTH RUC AND
GFS INDICATE UPPER LEVEL DIVERGENCE OVERNIGHT. LOCALLY HEAVY
RAINFALL EXPECTED. WILL INDICATE CATEGORICAL INTO THE THE EARLY
MORNING HOURS FOR THE MIDLANDS AND LIKELY POPS FOR THE CSRA.
POPS DECREASING TOWARDS DAWN. OVERNIGHT LOWS WILL RANGE FROM NEAR
70 NORTH TO THE MID 70S SOUTH. WITH WEAK PRESSURE GRADIENT ACROSS
THE STATE WILL HAVE LIGHT AND VARIABLE WINDS THROUGH TONIGHT.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH MONDAY NIGHT/...
THE NAM AND GFS DISPLAY THE FRONT LINGERING IN THE FORECAST AREA
THROUGH MONDAY NIGHT. ALTHOUGH THE FRONT MAY DRIFT SLIGHTLY
NORTH/SOUTH THROUGH THE PERIOD...IT WILL LIKELY HAVE LITTLE EFFECT
ON THE ACTUAL FORECAST. BUFKIT SHOWS ABUNDANT LOW LEVEL MOISTURE
THROUGH THE PERIOD. HIGH MOISTURE AND CONVERGENCE ASSOCIATED WITH
THE FRONT SUPPORT THE HIGHER GUIDANCE POPS ESPECIALLY IN THE NORTH
SECTION WHERE THE MODELS INDICATE STRONGER CONVERGENCE AND DEEPER
MOISTURE. LOCALLY HEAVY RAIN MAY OCCUR WITH PRECIPITABLE WATER
JUST OVER 2 INCHES AND A DIFLUENT 1000-500 MB THICKNESS PATTERN
WITH DEPTHS NEAR 574 DAM WHICH FAVORS HEAVY RAIN IN AUGUST. LEANED
TOWARD THE COOLER HIGH TEMPERATURE GUIDANCE AND WARMER LOW
TEMPERATURE GUIDANCE BECAUSE OF CLOUDINESS THROUGH THE PERIOD.
HAVE STAYED WITH OR RAISED SLIGHTLY POPS THROUGH MUCH OF THE
PERIOD.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
THE GFS AND ECMWF DISPLAY A STALLED FRONT OR TROUGH IN THE FORECAST AREA
THROUGH MUCH OF THE MEDIUM-RANGE PERIOD. THE MODELS SHOW DEEPER
MOISTURE SHIFTING EAST OF THE AREA WEDNESDAY. THE MODELS INDICATE HIGH
PRECIPITABLE WATER AND A CONTINUED THREAT OF HEAVY RAIN EARLY IN
THE PERIOD. LEANED TOWARD AN AVERAGE OF THE GFS...ECMWF...AND EKD
MOS FOR THE POP FORECAST. THE MOS SUPPORTS TEMPERATURES NEAR
CLIMATOLOGY.
&&
.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
SCATTERED SHOWERS WILL CONTINUE TO AFFECT THE TERMINALS IN THE NEAR
TERM...AND ARE EXPECTED TO GRADUALLY DISSIPATE DURING THE PRE-DAWN
HOURS. OTHERWISE...GUIDANCE SUGGESTING IFR CIGS
DEVELOPING...ALONG WITH SOME VSBY RESTRICTIONS...OVER OUR FA
OVERNIGHT...SO WILL MAINTAIN MENTION. SLOW IMPROVEMENT TO VFR
EXPECTED BY MIDDAY TO EARLY AFTERNOON TODAY. SHOWERS AND
THUNDERSTORMS EXPECTED LATER TODAY...AND ARE EXPECTED TO BE
DIURNALLY FAVORED. FOR NOW...WILL CARRY VCSH IN THE AFTERNOON.
EXTENDED AVIATION OUTLOOK...LATE NIGHT AND MORNING MVFR TO IFR
RESTRICTIONS IN LOW CLOUDS AND/OR FOG EXPECTED...ALONG WITH GOOD
CHANCES OF MAINLY DIURNAL THUNDERSTORMS...THROUGH TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1239 AM EDT SUN AUG 10 2014
.SYNOPSIS...
A NEARLY STATIONARY FRONTAL ZONE WILL REMAIN IN THE FORECAST AREA
THROUGH TUESDAY. THE FRONT WILL BRING NUMEROUS SHOWERS AND
THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
WIDESPREAD SHOWERS WITH ISOLATED THUNDERSTORMS EXPECTED ACROSS THE
MIDLANDS INTO THE EARLY MORNING HOURS. AIR MASS VERY MOIST AND
UNSTABLE WITH PWAT AROUND 2.1 INCHES. CANNOT RULE OUT WEAK UPPER
DISTURBANCE CROSSING THE AREA IN DIFLUENT FLOW ALOFT. BOTH RUC AND
GFS INDICATE UPPER LEVEL DIVERGENCE OVERNIGHT. LOCALLY HEAVY
RAINFALL EXPECTED. WILL INDICATE CATEGORICAL INTO THE THE EARLY
MORNING HOURS FOR THE MIDLANDS AND LIKELY POPS FOR THE CSRA.
POPS DECREASING TOWARDS DAWN. OVERNIGHT LOWS WILL RANGE FROM NEAR
70 NORTH TO THE MID 70S SOUTH. WITH WEAK PRESSURE GRADIENT ACROSS
THE STATE WILL HAVE LIGHT AND VARIABLE WINDS THROUGH TONIGHT.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH MONDAY NIGHT/...
THE NAM AND GFS DISPLAY THE FRONT LINGERING IN THE FORECAST AREA
THROUGH MONDAY NIGHT. ALTHOUGH THE FRONT MAY DRIFT SLIGHTLY
NORTH/SOUTH THROUGH THE PERIOD...IT WILL LIKELY HAVE LITTLE EFFECT
ON THE ACTUAL FORECAST. BUFKIT SHOWS ABUNDANT LOW LEVEL MOISTURE
THROUGH THE PERIOD. HIGH MOISTURE AND CONVERGENCE ASSOCIATED WITH
THE FRONT SUPPORT THE HIGHER GUIDANCE POPS ESPECIALLY IN THE NORTH
SECTION WHERE THE MODELS INDICATE STRONGER CONVERGENCE AND DEEPER
MOISTURE. LOCALLY HEAVY RAIN MAY OCCUR WITH PRECIPITABLE WATER
JUST OVER 2 INCHES AND A DIFLUENT 1000-500 MB THICKNESS PATTERN
WITH DEPTHS NEAR 574 DAM WHICH FAVORS HEAVY RAIN IN AUGUST. LEANED
TOWARD THE COOLER HIGH TEMPERATURE GUIDANCE AND WARMER LOW
TEMPERATURE GUIDANCE BECAUSE OF CLOUDINESS THROUGH THE PERIOD.
HAVE STAYED WITH OR RAISED SLIGHTLY POPS THROUGH MUCH OF THE
PERIOD.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
THE GFS AND ECMWF DISPLAY A STALLED FRONT OR TROUGH IN THE FORECAST AREA
THROUGH MUCH OF THE MEDIUM-RANGE PERIOD. THE MODELS SHOW DEEPER
MOISTURE SHIFTING EAST OF THE AREA WEDNESDAY. THE MODELS INDICATE HIGH
PRECIPITABLE WATER AND A CONTINUED THREAT OF HEAVY RAIN EARLY IN
THE PERIOD. LEANED TOWARD AN AVERAGE OF THE GFS...ECMWF...AND EKD
MOS FOR THE POP FORECAST. THE MOS SUPPORTS TEMPERATURES NEAR
CLIMATOLOGY.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
SCATTERED SHOWERS AND TSRA WILL CONTINUE TO AFFECT THE TERMINALS
IN THE NEAR TERM...AND ARE EXPECTED TO GRADUALLY DISSIPATE LATER
TONIGHT. OTHERWISE...GUIDANCE SUGGESTING IFR CIGS
DEVELOPING...ALONG WITH SOME VSBY RESTRICTIONS...OVER OUR FA LATE
TONIGHT. WILL MAINTAIN MENTION OF SUCH. SLOW IMPROVEMENT TO VFR
EXPECTED BY MIDDAY TO EARLY AFTERNOON SUNDAY. SHOWERS AND
THUNDERSTORMS EXPECTED SUNDAY...AND ARE EXPECTED TO BE DIURNALLY
FAVORED. FOR NOW...WILL CARRY VCSH IN THE AFTERNOON.
EXTENDED AVIATION OUTLOOK...LATE NIGHT AND MORNING MVFR TO IFR
RESTRICTIONS IN LOW CLOUDS AND/OR FOG EXPECTED...ALONG WITH GOOD
CHANCES OF MAINLY DIURNAL THUNDERSTORMS...THROUGH TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
944 PM CDT MON AUG 11 2014
.DISCUSSION...
257 PM CDT
NEAR TERM FORECAST FOCUS DEALS SHOWER/THUNDERSTORM COVERAGE THROUGH
THIS EVENING...AND ADDITIONAL SHOWER CHANCES THROUGH AT LEAST
TUESDAY MORNING ESPECIALLY OVER EASTERN PARTS OF THE FORECAST AREA.
EARLY AFTERNOON SURFACE ANALYSIS DEPICTS TWO SEPARATE AREAS OF LOW
PRESSURE...ONE OVER CENTRAL WISCONSIN AND THE OTHER ACROSS WESTERN
OHIO. BOTH OF THESE SURFACE LOWS WERE ASSOCIATED WITH FAIRLY STOUT
MID-LEVEL SHORT WAVES WHICH WERE ALSO RESPONSIBLE FOR A LARGE AREA
OF SHOWERS AND THUNDERSTORMS FROM NORTHERN WI ACROSS LAKE MICHIGAN
TO THE SOUTHERN GREAT LAKES/OHIO VALLEY REGION THIS AFTERNOON. FOR
OUR LOCAL AREA...THE STRONG SHORT WAVE TROUGH SEEN IN GOES VAPOR
IMAGERY OVER MINNESOTA WILL BE THE MAIN DRIVER IN OUR WEATHER AND
PRECIP TRENDS OVER THE NEXT 18 HOURS OR SO...AS IT CONTINUES TO DIG
SOUTHEAST ACROSS NORTHERN IL THROUGH TUESDAY MORNING. ALONG WITH ITS
SURFACE REFLECTION OVER WI...A COLD FRONT EXTENDING ALONG THE
MISSISSIPPI RIVER WILL PUSH SOUTHEAST THROUGH THIS EVENING...AND
WILL BE THE FOCUS FOR SHOWERS AND A FEW THUNDERSTORMS. WHILE SURFACE
WINDS WERE ALREADY WEST-NORTHWEST AHEAD OF THE FRONT ITSELF...THUS
REDUCING CONVERGENCE ALONG THE BOUNDARY...STEEP LOW LEVEL LAPSE
RATES AND RAP MESOANALYSIS MLCAPES OF 500-1000 J/KG SHOULD BE ENOUGH
TO SUSTAIN SHOWERS/THUNDERSTORMS AHEAD OF THE FRONT THROUGH EARLY
EVENING. IN ADDITION...A FEW SHOWERS HAD DEVELOPED ALONG THE LAKE
BREEZE FROM SOUTHEAST WI INTO NORTHEAST IL...AND THESE SHOWERS AND
ISOLATED THUNDERSTORMS MAY ALSO FESTER A BIT AHEAD OF THE FRONT. ANY
OF THE STRONGER STORMS MAY PRODUCE BRIEF HEAVY DOWNPOURS...AND
PERHAPS SOME BRIEF GUSTY WINDS WITH STORMS ALONG THE FRONT DUE TO
THE STEEP LOW LEVEL LAPSE RATES.
THE STRONG MINNESOTA SHORT WAVE WILL AMPLIFY/DEEPEN AN UPPER TROUGH
OVER THE WESTERN LAKES TONIGHT...WITH THE SURFACE LOWS CONSOLIDATING
AND DEEPENING OVER LOWER MICHIGAN. A FEW SHOWERS MAY LINGER OVER
NORTHEASTERN PARTS OF THE CWA AND SOUTHERN LAKE MICHIGAN TUESDAY
MORNING AS THE MAIN VORT MOVES THROUGH...BEFORE SUBSIDENCE INDICATED
BY 40 METER H5 HEIGHT RISES SPREADS IN DURING THE AFTERNOON. NORTH
WINDS STRENGTHENING BEHIND THE DEEPENING LOW WILL EVENTUALLY PULL
COOLER AND DRIER AIR INTO THE REGION TUESDAY AFTERNOON/NIGHT. AFTER
TEMPS REACHING THE LOW 80S TODAY (WHERE CLOUDS DID NOT PREVENT
IT)... COOLER 70S EXPECTED FOR HIGHS TUESDAY...AND SOME LOW 50S FOR
LOWS TUESDAY NIGHT!
GUIDANCE INDICATES ANOTHER WEAKER SHORT-WAVE DROPPING SOUTHEAST
ACROSS THE WESTERN LAKES WEDNESDAY...WITH A WEAK SURFACE WAVE AND
TROUGH PUSHING SOUTH ACROSS THE REGION DURING THE AFTERNOON. SOME
MODELS ARE TRYING TO SQUEEZE OUT A LITTLE PATCHY LIGHT QPF HINTING
AT SOME SHOWERS ALONG/AHEAD OF THE TROUGH DURING THE AFTERNOON...
THOUGH MOST OF THIS IS ACROSS WI/NORTHEAST IA AND HAVE LOW ENOUGH
CONFIDENCE IN IT IMPACTING THE FORECAST AREA TO LEAVE IT OUT OF THE
FORECAST AT THIS TIME. SIMILAR POTENTIAL FOR THURSDAY AFTERNOON
FARTHER SOUTH DEPENDING UPON WHERE THE TROUGH IS BY THEN. OTHERWISE
HIGH PRESSURE BUILDS INTO THE REGION WEDNESDAY NIGHT AND THURSDAY
WITH LIGHTER WINDS AND A MODERATION IN TEMPS BACK TO THE 75-80
DEGREE RANGE THURSDAY AND AROUND 80 FRIDAY WITH ATTENDANT LAKE
BREEZES. THE HIGH THEN DRIFTS OFF TO THE EAST FRIDAY NIGHT AND
SATURDAY...WITH AN EVENTUAL RETURN OF WARM/MOIST ADVECTION FLOW INTO
THE WEEKEND AND EARLY NEXT WEEK. IN THE EXTENDED RANGE...GEM...GFS
AND ECMWF ALL BRING SOME PRECIP POTENTIAL BACK TO THE AREA BY FRIDAY
NIGHT...THOUGH THERE ARE SOME TIMING DIFFERENCES BETWEEN THE GLOBAL
GUIDANCE BY DAYS 6-7. THUS HAVE MAINTAINED BLENDED GUIDANCE APPROACH
WITH GENERALLY LOW-CHANCE POPS AND TEMPS WARMING BACK INTO THE
LOW-MID 80S THROUGH THE WEEKEND.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* CHANCE FOR SHRA EARLY TUESDAY MORNING.
* CIGS DROPPING TO MVFR OVERNIGHT WITH A PERIOD OF IFR CIGS EARLY
TUESDAY MORNING...WITH MVFR CIGS LINGERING UNTIL EARLY AFTERNOON.
* NWLY WINDS WINDS INCREASING TUESDAY MORNING WITH GUSTS UP TO
20-25KT POSSIBLE FROM LATE MORNING TO LATE AFTERNOON.
KREIN
//DISCUSSION...UPDATED 00Z...
A COMPLEX UPPER LEVEL PATTERN IS RESPONSIBLE FOR BRINGING
UNSETTLED WEATHER TO THE AREA...THOUGH THE PATTERN REMAINS WEAK AT
THE SFC. A LINE OF SHRA/TSRA IN MOVING THROUGH NERN IL...AND INTO
NWRN IN WITH AN UPPER LEVEL IMPULSE CROSSING THE REGION. A MODEST
TS CELL THAT HAD BEEN HEADING TOWARD THE CHICAGO AREA TERMINALS
HAS LARGELY FIZZLED OUT...THOUGH IT COULD STILL CLIP MDW.
ALSO...SOME CELLS DEVELOPING BEHIND THE MAIN LINE COULD STILL
IMPACT THE TERMINALS...SO WILL MAINTAIN THE SHORT PREVAILING TS
GROUP...THOUGH PROBABILITY OF DIRECT IMPACT AT THE TERMINALS IS
DECREASING. ANOTHER MID LEVEL IMPULSE DROPPING THROUGH WISCONSIN
SHOULD CROSS ACROSS NRN IL/IN OVERNIGHT TONIGHT. BY THE LATE
EVENING HOURS...DRIER AIR ALOFT IS EXPECTED TO OVERSPREAD THE LOW
LEVEL MOIST AIR...LEADING TO THE POTENTIAL FOR A STRATUS DECK
LOWERING INTO IFR LEVELS FOR THE EARLY MORNING HOURS. WITH DIURNAL
WARMING...CIGS SHOULD LIFT MVFR BY ARND 14Z AND IMPROVE TO VFR BY
LATE AFTERNOON. HIGH PRESSURE BUILDING OVER THE CENTRAL PLAINS AND
A DEEPENING SFC LOW OVER MICHIGAN AND THE CENTRAL GREAT LAKES
WILL BRING STRENGTHENING NW WINDS THROUGH THE DAY TOMORROW...
GUSTING TO 20-25KT FROM LATE MORNING THROUGH LATE AFTERNOON. AS
THE HIGH SPREADS EAST ACROSS THE MIDDLE MISSISSIPPI VALLEY LATE
TOMORROW AFTERNOON AND EARLY TOMORROW EVENING...THE NWLY WINDS
SHOULD LOSE THE GUSTINESS AND WEAKEN.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MEDIUM TO HIGH CONFIDENCE IN CIG TRENDS OVERNIGHT.
* LOW TO MEDIUM CONFIDENCE IN ADDITIONAL SHRA DURG THE EARLY
MORNING HOURS.
* MEDIUM TO HIGH CONFIDENCE IN WIND TRENDS OVERNIGHT AND
TOMORROW.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...VFR. WX NIL. NORTHWEST WINDS WITH POSSIBLE SHIFT TO
NORTHEAST WITH LAKE BREEZE.
THURSDAY...VFR. WX NIL. NORTHEAST WINDS UP TO 10KT.
FRIDAY...VFR. LIGHT SOUTH WINDS TURN SOUTHEAST WITH LAKE BREEZE IN
THE AFTERNOON. SLIGHT CHANCE TSRA OVERNIGHT.
SATURDAY AND SUNDAY...SOUTH WINDS TO 10 KT. SLIGHT CHANCE TSRA
OVERNIGHT.
KREIN
&&
.MARINE...
403 PM CDT
THE HIGHER WINDS AND WAVES FROM EARLIER THIS MORNING HAVE SINCE
DIMINISHED/SUBSIDED TODAY AS A WEAKER SURFACE GRADIENT HAS SETTLED
IN...BETWEEN WEAKENING LOW PRESSURE WEST OF THE LAKE AND A
NORTHWARD MOVING LOW PRESSURE OVER THE OHIO VALLEY. THE GENERALLY
LIGHTER WINDS CURRENTLY OVER THE LAKE WILL OBSERVE AN INCREASING
TREND THIS EVENING INTO TONIGHT AS THE OHIO VALLEY LOW DEEPENS
WHILE LIFTING THROUGH THE EASTERN GREAT LAKES...WITH NORTHERLY TO
30 KT WINDS LIKELY BY LATE TONIGHT AND EARLY TUESDAY MORNING.
LATEST TRENDS HAVE SHOWN THAT NORTHERLY GALES WILL BE POSSIBLE
TUESDAY MORNING INTO TUESDAY AFTERNOON MAINLY FOR THE NORTHERN
HALF OF THE LAKE...INSTEAD OF THE PREVIOUSLY MENTIONED OCCASIONAL
GALE FORCE GUSTS. WITH THIS POSSIBILITY...HAVE ISSUED A GALE WATCH
FOR THE NORTH HALF THIS AFTERNOON FOR THIS PERIOD. WILL NEED TO
CONTINUE TO MONITOR LATER TRENDS FOR THIS INCREASED POSSIBILITY OF
GALES. THESE NORTHERLY WINDS WILL ALLOW WAVES TO BUILD DOWN THE
LENGTH OF THE LAKE...WITH WINDS AND WAVES HAZARDOUS FOR SMALL
CRAFT LIKELY TUESDAY INTO TUESDAY NIGHT AND WEDNESDAY MORNING.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014...9 AM TUESDAY TO 4 AM
WEDNESDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...9 AM TUESDAY TO 10 AM
WEDNESDAY.
LM...GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...7 AM
TUESDAY TO 3 PM TUESDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...9 AM TUESDAY TO 4
AM WEDNESDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...9 AM TUESDAY TO 10
AM WEDNESDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
651 PM CDT MON AUG 11 2014
.DISCUSSION...
257 PM CDT
NEAR TERM FORECAST FOCUS DEALS SHOWER/THUNDERSTORM COVERAGE THROUGH
THIS EVENING...AND ADDITIONAL SHOWER CHANCES THROUGH AT LEAST
TUESDAY MORNING ESPECIALLY OVER EASTERN PARTS OF THE FORECAST AREA.
EARLY AFTERNOON SURFACE ANALYSIS DEPICTS TWO SEPARATE AREAS OF LOW
PRESSURE...ONE OVER CENTRAL WISCONSIN AND THE OTHER ACROSS WESTERN
OHIO. BOTH OF THESE SURFACE LOWS WERE ASSOCIATED WITH FAIRLY STOUT
MID-LEVEL SHORT WAVES WHICH WERE ALSO RESPONSIBLE FOR A LARGE AREA
OF SHOWERS AND THUNDERSTORMS FROM NORTHERN WI ACROSS LAKE MICHIGAN
TO THE SOUTHERN GREAT LAKES/OHIO VALLEY REGION THIS AFTERNOON. FOR
OUR LOCAL AREA...THE STRONG SHORT WAVE TROUGH SEEN IN GOES VAPOR
IMAGERY OVER MINNESOTA WILL BE THE MAIN DRIVER IN OUR WEATHER AND
PRECIP TRENDS OVER THE NEXT 18 HOURS OR SO...AS IT CONTINUES TO DIG
SOUTHEAST ACROSS NORTHERN IL THROUGH TUESDAY MORNING. ALONG WITH ITS
SURFACE REFLECTION OVER WI...A COLD FRONT EXTENDING ALONG THE
MISSISSIPPI RIVER WILL PUSH SOUTHEAST THROUGH THIS EVENING...AND
WILL BE THE FOCUS FOR SHOWERS AND A FEW THUNDERSTORMS. WHILE SURFACE
WINDS WERE ALREADY WEST-NORTHWEST AHEAD OF THE FRONT ITSELF...THUS
REDUCING CONVERGENCE ALONG THE BOUNDARY...STEEP LOW LEVEL LAPSE
RATES AND RAP MESOANALYSIS MLCAPES OF 500-1000 J/KG SHOULD BE ENOUGH
TO SUSTAIN SHOWERS/THUNDERSTORMS AHEAD OF THE FRONT THROUGH EARLY
EVENING. IN ADDITION...A FEW SHOWERS HAD DEVELOPED ALONG THE LAKE
BREEZE FROM SOUTHEAST WI INTO NORTHEAST IL...AND THESE SHOWERS AND
ISOLATED THUNDERSTORMS MAY ALSO FESTER A BIT AHEAD OF THE FRONT. ANY
OF THE STRONGER STORMS MAY PRODUCE BRIEF HEAVY DOWNPOURS...AND
PERHAPS SOME BRIEF GUSTY WINDS WITH STORMS ALONG THE FRONT DUE TO
THE STEEP LOW LEVEL LAPSE RATES.
THE STRONG MINNESOTA SHORT WAVE WILL AMPLIFY/DEEPEN AN UPPER TROUGH
OVER THE WESTERN LAKES TONIGHT...WITH THE SURFACE LOWS CONSOLIDATING
AND DEEPENING OVER LOWER MICHIGAN. A FEW SHOWERS MAY LINGER OVER
NORTHEASTERN PARTS OF THE CWA AND SOUTHERN LAKE MICHIGAN TUESDAY
MORNING AS THE MAIN VORT MOVES THROUGH...BEFORE SUBSIDENCE INDICATED
BY 40 METER H5 HEIGHT RISES SPREADS IN DURING THE AFTERNOON. NORTH
WINDS STRENGTHENING BEHIND THE DEEPENING LOW WILL EVENTUALLY PULL
COOLER AND DRIER AIR INTO THE REGION TUESDAY AFTERNOON/NIGHT. AFTER
TEMPS REACHING THE LOW 80S TODAY (WHERE CLOUDS DID NOT PREVENT
IT)... COOLER 70S EXPECTED FOR HIGHS TUESDAY...AND SOME LOW 50S FOR
LOWS TUESDAY NIGHT!
GUIDANCE INDICATES ANOTHER WEAKER SHORT-WAVE DROPPING SOUTHEAST
ACROSS THE WESTERN LAKES WEDNESDAY...WITH A WEAK SURFACE WAVE AND
TROUGH PUSHING SOUTH ACROSS THE REGION DURING THE AFTERNOON. SOME
MODELS ARE TRYING TO SQUEEZE OUT A LITTLE PATCHY LIGHT QPF HINTING
AT SOME SHOWERS ALONG/AHEAD OF THE TROUGH DURING THE AFTERNOON...
THOUGH MOST OF THIS IS ACROSS WI/NORTHEAST IA AND HAVE LOW ENOUGH
CONFIDENCE IN IT IMPACTING THE FORECAST AREA TO LEAVE IT OUT OF THE
FORECAST AT THIS TIME. SIMILAR POTENTIAL FOR THURSDAY AFTERNOON
FARTHER SOUTH DEPENDING UPON WHERE THE TROUGH IS BY THEN. OTHERWISE
HIGH PRESSURE BUILDS INTO THE REGION WEDNESDAY NIGHT AND THURSDAY
WITH LIGHTER WINDS AND A MODERATION IN TEMPS BACK TO THE 75-80
DEGREE RANGE THURSDAY AND AROUND 80 FRIDAY WITH ATTENDANT LAKE
BREEZES. THE HIGH THEN DRIFTS OFF TO THE EAST FRIDAY NIGHT AND
SATURDAY...WITH AN EVENTUAL RETURN OF WARM/MOIST ADVECTION FLOW INTO
THE WEEKEND AND EARLY NEXT WEEK. IN THE EXTENDED RANGE...GEM...GFS
AND ECMWF ALL BRING SOME PRECIP POTENTIAL BACK TO THE AREA BY FRIDAY
NIGHT...THOUGH THERE ARE SOME TIMING DIFFERENCES BETWEEN THE GLOBAL
GUIDANCE BY DAYS 6-7. THUS HAVE MAINTAINED BLENDED GUIDANCE APPROACH
WITH GENERALLY LOW-CHANCE POPS AND TEMPS WARMING BACK INTO THE
LOW-MID 80S THROUGH THE WEEKEND.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* CHANCE FOR A BRIEF PERIOD OF SHRA/TSRA EARLY EVENING.
* CHANCE FOR SHRA EARLY TUESDAY MORNING.
* CIGS DROPPING TO MVFR OVERNIGHT WITH A PERIOD OF IFR CIGS EARLY
TUESDAY MORNING...WITH MVFR CIGS LINGERING UNTIL EARLY AFTERNOON.
* NWLY WINDS WINDS INCREASING TUESDAY MORNING WITH GUSTS UP TO
20-25KT POSSIBLE FROM LATE MORNING TO LATE AFTERNOON.
KREIN
//DISCUSSION...UPDATED 00Z...
A COMPLEX UPPER LEVEL PATTERN IS RESPONSIBLE FOR BRINGING
UNSETTLED WEATHER TO THE AREA...THOUGH THE PATTERN REMAINS WEAK AT
THE SFC. A LINE OF SHRA/TSRA IN MOVING THROUGH NERN IL...AND INTO
NWRN IN WITH AN UPPER LEVEL IMPULSE CROSSING THE REGION. A MODEST
TS CELL THAT HAD BEEN HEADING TOWARD THE CHICAGO AREA TERMINALS
HAS LARGELY FIZZLED OUT...THOUGH IT COULD STILL CLIP MDW.
ALSO...SOME CELLS DEVELOPING BEHIND THE MAIN LINE COULD STILL
IMPACT THE TERMINALS...SO WILL MAINTAIN THE SHORT PREVAILING TS
GROUP...THOUGH PROBABILITY OF DIRECT IMPACT AT THE TERMINALS IS
DECREASING. ANOTHER MID LEVEL IMPULSE DROPPING THROUGH WISCONSIN
SHOULD CROSS ACROSS NRN IL/IN OVERNIGHT TONIGHT. BY THE LATE
EVENING HOURS...DRIER AIR ALOFT IS EXPECTED TO OVERSPREAD THE LOW
LEVEL MOIST AIR...LEADING TO THE POTENTIAL FOR A STRATUS DECK
LOWERING INTO IFR LEVELS FOR THE EARLY MORNING HOURS. WITH DIURNAL
WARMING...CIGS SHOULD LIFT MVFR BY ARND 14Z AND IMPROVE TO VFR BY
LATE AFTERNOON. HIGH PRESSURE BUILDING OVER THE CENTRAL PLAINS AND
A DEEPENING SFC LOW OVER MICHIGAN AND THE CENTRAL GREAT LAKES
WILL BRING STRENGTHENING NW WINDS THROUGH THE DAY TOMORROW...
GUSTING TO 20-25KT FROM LATE MORNING THROUGH LATE AFTERNOON. AS
THE HIGH SPREADS EAST ACROSS THE MIDDLE MISSISSIPPI VALLEY LATE
TOMORROW AFTERNOON AND EARLY TOMORROW EVENING...THE NWLY WINDS
SHOULD LOSE THE GUSTINESS AND WEAKEN.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* LOW CONFIDENCE IN TSRA DIRECTLY IMPACTING THE TERMINALS EARLY
THIS EVENING.
* MEDIUM TO HIGH CONFIDENCE IN CIG TRENDS OVERNIGHT.
* LOW TO MEDIUM CONFIDENCE IN ADDITIONAL SHRA DURG THE EARLY
MORNING HOURS.
* MEDIUM TO HIGH CONFIDENCE IN WIND TRENDS OVERNIGHT AND
TOMORROW.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...VFR. WX NIL. NORTHWEST WINDS WITH POSSIBLE SHIFT TO
NORTHEAST WITH LAKE BREEZE.
THURSDAY...VFR. WX NIL. NORTHEAST WINDS UP TO 10KT.
FRIDAY...VFR. LIGHT SOUTH WINDS TURN SOUTHEAST WITH LAKE BREEZE IN
THE AFTERNOON. SLIGHT CHANCE TSRA OVERNIGHT.
SATURDAY AND SUNDAY...SOUTH WINDS TO 10 KT. SLIGHT CHANCE TSRA
OVERNIGHT.
KREIN
&&
.MARINE...
403 PM CDT
THE HIGHER WINDS AND WAVES FROM EARLIER THIS MORNING HAVE SINCE
DIMINISHED/SUBSIDED TODAY AS A WEAKER SURFACE GRADIENT HAS SETTLED
IN...BETWEEN WEAKENING LOW PRESSURE WEST OF THE LAKE AND A
NORTHWARD MOVING LOW PRESSURE OVER THE OHIO VALLEY. THE GENERALLY
LIGHTER WINDS CURRENTLY OVER THE LAKE WILL OBSERVE AN INCREASING
TREND THIS EVENING INTO TONIGHT AS THE OHIO VALLEY LOW DEEPENS
WHILE LIFTING THROUGH THE EASTERN GREAT LAKES...WITH NORTHERLY TO
30 KT WINDS LIKELY BY LATE TONIGHT AND EARLY TUESDAY MORNING.
LATEST TRENDS HAVE SHOWN THAT NORTHERLY GALES WILL BE POSSIBLE
TUESDAY MORNING INTO TUESDAY AFTERNOON MAINLY FOR THE NORTHERN
HALF OF THE LAKE...INSTEAD OF THE PREVIOUSLY MENTIONED OCCASIONAL
GALE FORCE GUSTS. WITH THIS POSSIBILITY...HAVE ISSUED A GALE WATCH
FOR THE NORTH HALF THIS AFTERNOON FOR THIS PERIOD. WILL NEED TO
CONTINUE TO MONITOR LATER TRENDS FOR THIS INCREASED POSSIBILITY OF
GALES. THESE NORTHERLY WINDS WILL ALLOW WAVES TO BUILD DOWN THE
LENGTH OF THE LAKE...WITH WINDS AND WAVES HAZARDOUS FOR SMALL
CRAFT LIKELY TUESDAY INTO TUESDAY NIGHT AND WEDNESDAY MORNING.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014...9 AM TUESDAY TO 4 AM
WEDNESDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...9 AM TUESDAY TO 10 AM
WEDNESDAY.
LM...GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...7 AM
TUESDAY TO 3 PM TUESDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...9 AM TUESDAY TO 4
AM WEDNESDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...9 AM TUESDAY TO 10
AM WEDNESDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1255 PM CDT SUN AUG 10 2014
.DISCUSSION...
1108 AM CDT
HAVE MADE A FEW ADJUSTMENTS TO GRIDS THIS MORNING. ACCOUNTING FOR
MORE ORGANIZED AREA OF SHOWERS LIFTING INTO BENTON AND JASPER THAT
DID HAVE ONE ISOLATED CG LIGHTNING STRIKE IN THE 10AM HOUR...HAVE
BUMPED POPS TO LIKELY/HIGH END CHC IN THAT AREA THROUGH MID DAY.
THIS AREA OF SHOWERS SHOULD TEND TO WEAKEN AS SHORT WAVE/VORT NOTED
ON W/V IMAGERY PASSES OFF TO EAST. THEN THIS AFTERNOON...ANOTHER
WEAK WAVE WILL PUSH ACROSS THE REGION...WITH BETTER FORCING FOR
ASCENT IN PRIMARILY SOUTHERN CWA. NEAR TERM GUIDANCE ALSO KEYING ON
BOUNDARY LAYER CONVERGENCE AS LAKE BREEZE PUSHES INLAND TO FOCUS A
BIT BETTER CHANCE FOR WIDELY SCATTERED SHOWERS INTO THE SOUTHEASTERN
THIRD OF THE CWA. DEWPOINTS IN THE MID AND UPPER 60S AND MINOR
WARMING DESPITE WIDESPREAD CLOUD COVER WILL ENABLE WEAK INSTABILITY
TO DEVELOP...SO HAVE INDICATED ISOLATED TSRA IN THE GRIDS
ALONG/SOUTH OF I-80. WITH THE THICKER CLOUDS IN THE FAR SOUTHEAST
CWA...HAVE SHAVED A FEW DEGREES OFF HIGHS THERE TO THE UPPER 70S TO
AROUND. ELSEWHERE...850/925 MB TEMPS SUPPORT GOING HIGHS IN LOWER
80S...SO ONLY MINOR TWEAKS...THOUGH SPOTS THAT SEE A BIT MORE
SUNSHINE COULD REACH THE MID 80S.
RC
//PREV DISCUSSION...
312 AM CDT
TODAY THROUGH TONIGHT...
BENIGN WEATHER HAS CONTINUED EARLY THIS MORNING WITH A SPRAWLING SFC
RIDGE OF HIGH PRESSURE COVERING MUCH OF THE GREAT LAKES REGION. A
WEAK LOW PRESSURE WAS TRYING TO LIFT NORTH/NORTHEAST ACROSS CENTRAL
TENN. SFC TEMPS HAVE BEEN SLOW TO COOL THIS MORNING...GENERALLY A
RESULT FROM SOME MID-DECK CLOUDS. EXPECT TEMPS TO BOTTOM OUT AROUND
THE MID 60S BY DAYBREAK.
A MID-LVL WAVE OVER SOUTH DAKOTA/NEBRASKA IS PROGGED TO SLIDE
EAST TODAY...AND COULD BRING AN ISOLATED SHOWER/THUNDERSTORM TO THE
FORECAST AREA THIS AFTERNOON...MAINLY SOUTH OF I-80. THIS APPEARS TO
BE MORE DIURNALLY DRIVEN...AND NOT EXPECTING MUCH COVERAGE WITH ANY
PRECIP THAT DEVELOPS THIS AFTERNOON. TEMPS WILL WARM INTO THE LOW
80S FOR MUCH OF THE AREA...THE EXCEPTION WILL BE AREAS ADJACENT TO
LAKE MICHIGAN WITH AN ONSHORE FLOW KEEPING TEMPS IN THE MID/UPR 70S.
PRECIP SHUD STEADILY DIMINISH IN COVERAGE SHORTLY AFTER SUNSET.
GUIDANCE CONTINUES TO PROG CONSIDERABLE MOISTURE THROUGHOUT THE
MID-LVLS SUGGESTIVE OF A MOSTLY CLOUDY NIGHT. THUS EXPECT TEMPS TO
HOLD UP IN THE MID 60S.
MONDAY THROUGH TUESDAY...
STUBBORN SFC RIDGE FINALLY ERODES ENOUGH TO ALLOW A MID-LVL VORT
OVER CENTRAL CANADA TO SLIDE SOUTHEAST ACROSS THE UPPER MIDWEST MON.
GUIDANCE DOES SUGGEST A WEAKER MID-LVL FEATURE WILL TRY TO LIFT
NORTHEAST ACROSS THE OHIO VALLEY MON. WITH SLIGHTLY STRONGER FORCING
AND INCREASED MOISTURE THE BEST TIMING FOR PRECIP APPEARS TO BE IN
THE AFTN/EVE MON HOURS. LAPSE RATES ARE PROGGED TO STEEPEN MON
AFTN...HOWEVER THE COOLER AIR ALOFT DOES NOT ARRIVE UNTIL LATE MON
NGT. THIS COUPLED WITH THE LACK OF GOOD FORCING MON SHUD LIMIT ANY
CONVECTION FROM BECOMING ORGANIZED. HAVE HELD ONTO HIGHS ARND 80 OR
LOW 80S MON...ALTHOUGH WITH CONSIDERABLE CLOUD COVER AND WINDS
LIKELY TURNING NW BY LATE MORNING...TEMPS COULD END UP STRUGGLING TO
WARM BEYOND THE 70S.
TROUGH AXIS PIVOTS EAST TUE...WITH BROAD SFC RIDGING RETURNING TO
THE REGION AND PROVIDING A RETURN TO DRY WEATHER. TEMPS WILL BE MUCH
COOLER TUE WITH THE ARRIVAL OF A 850MB THERMAL TROUGH OF 7 TO 9 DEG
C. THIS COUPLED WITH NORTHERLY WINDS SUGGESTS HIGHS WILL BE IN THE
LOW/MID 70S. SFC RIDGE OVERHEAD TUE NIGHT WILL KEEP P-CLOUDY SKIES
AND ALLOW TEMPS TO RADIATE INTO THE LOW 50S...POSSIBLY THE UPR 40S
IN THE TRADITIONAL COOL SPOTS.
CONFIDENCE...HIGH.
WEDNESDAY THROUGH SATURDAY...
ENSEMBLES CONTINUE TO PROG A RETURN TO THE NORTH ATLANTIC MID-LVL
BLOCK...WHICH INDICATES THE TROUGH OVER THE GREAT LAKES MID-WEEK
WILL LIKELY PERSIST THRU THE END OF THE WEEK. HIGH AMPLITUDE RIDGING
ACROSS THE CANADIAN ROCKIES ALSO SUGGESTS THAT THE SFC RIDGE WILL
LOCK OVERHEAD WITH A DRY NORTHWEST FLOW FOR THE GREAT LAKES REGION.
AT THE UPCOMING WEEKEND APPROACHES SEVERAL ENSEMBLE MEMBERS INDICATE
THE NORTH ATLANTIC BLOCK WILL DISSOLVE AND ALLOW THE TROUGH OVER THE
GREAT LAKES TO KICK EAST AND A SEMI-ZONAL FLOW TO ARRIVE FOR THE MID
SECTIONS OF THE COUNTRY. TEMPS WILL GENERALLY BE IN THE 70S TO ARND
80.
CONFIDENCE...HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* NORTHEAST WINDS 10-12KT THRU 00Z.
* CHANCE OF SHRA OVERNIGHT/MONDAY MORNING.
* POTENTIAL FOR MVFR CIGS MONDAY MORNING.
* LAKE BREEZE MONDAY AFTERNOON. CMS
//DISCUSSION...UPDATED 18Z...
NORTHEAST WINDS CONTINUE TO SLOWLY INCREASE EARLY THIS AFTERNOON
WITH ONE MINUTE DATA FROM ORD SHOWING 10-12KTS FOR THE PAST HOUR.
FORECAST SOUNDINGS SUPPORT PREVAILING SPEEDS OF 10KTS OR SLIGHTLY
HIGHER THRU LATE AFTERNOON. SPEEDS WILL DIMINISH UNDER 10KTS LATE
THIS AFTERNOON INTO EARLY THIS EVENING AND THIS MAY OCCUR A LITTLE
BEFORE 00Z. WINDS WILL THEN TURN MORE NORTHERLY THIS EVENING AS
SPEEDS DIMINISH TO 5KTS OR LESS. WINDS MAY BECOME LIGHT AND
VARIABLE OVERNIGHT INTO MONDAY MORNING AND THEN TURN BACK NORTH OR
NORTHWESTERLY MONDAY MORNING. GRADIENT WILL BE WEAK ENOUGH TO
ALLOW A LAKE BREEZE TO FORM MONDAY AFTERNOON AND SHOULD ALLOW IT
TO MOVE FAR ENOUGH INLAND TO REACH ORD/MDW.
SHOWERS CONTINUE TO DEVELOP BETWEEN IKK AND GYY AND THESE WILL
DRIFT NORTHWEST THROUGH THE AFTERNOON WITH ADDITIONAL SHOWERS
POSSIBLE BUT MAINLY SOUTH AND SOUTHWEST OF THE TERMINALS. ADDED
VICINITY MENTION AT GYY BUT NO MENTION ELSEWHERE WITH ISOLATED
COVERAGE/SHORT DURATION OF ANYTHING FURTHER NORTH.
A BIT STRONGER UPPER WAVE ARRIVES LATE TONIGHT INTO MONDAY
MORNING. THERE REMAINS SOME UNCERTAINTY REGARDING TIMING AND
COVERAGE OF SHOWERS WITH THIS FEATURE BUT THERE IS SOME CONSENSUS
OF A PERIOD OF SHOWERS OVERNIGHT INTO MID MORNING MONDAY. DUE TO
LOWER CONFIDENCE...ONLY INCLUDED PROB MENTION BUT IF TRENDS
CONTINUE A PERIOD OF PREVAILING SHOWERS IS POSSIBLE.
AS LOW LEVEL MOISTURE INCREASES ACROSS THE AREA ALONG WITH THE
COMBINATION OF ANY SHOWERS OVERNIGHT...THE LOW LEVELS WILL BECOME
SATURATED WHICH MAY RESULT IN LIGHT FOG BUT PERHAPS LOWER CIGS
WILL BE MORE COMMON. ADDED MENTION OF LOW MVFR CLOUDS BUT ONLY
INCLUDED A CIG AT GYY. IF MVFR CIGS WERE TO DEVELOP...THEY WOULD
LIKELY SCATTER/LIFT FAIRLY QUICKLY MONDAY MORNING. CMS
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH FOR WINDS THROUGH MONDAY MORNING...MEDIUM FOR LAKE BREEZE
MONDAY AFTERNOON.
* MEDIUM FOR SHRA OVERNIGHT...LOW FOR TIMING/COVERAGE.
* LOW FOR MVFR CIGS MONDAY MORNING. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...VFR TO MVFR. CHANCE TSRA. NORTH TO NORTHEAST WINDS.
TUESDAY...VFR. CHANCE TSRA. GUSTY NORTH TO NORTHWEST WINDS.
WEDNESDAY...VFR. NORTHWEST WINDS.
THURSDAY...VFR. LIGHT NORTHWEST WINDS EARLY WITH AFTERNOON SHIFT
TO NORTHEAST POSSIBLE WITH LAKE BREEZE.
FRIDAY...VFR. SOUTH TO SOUTHWEST WINDS.
SATURDAY...VFR. EAST WINDS. CHANCE OF THUNDERSTORMS.
LENNING
&&
.MARINE...
319 AM CDT
LOW PRESSURE DEEPENING OVER THE OHIO VALLEY WILL LIFT INTO THE
CENTRAL AND THEN EASTERN GREAT LAKES OVER THE NEXT TWO
DAYS...TURNING WINDS NORTH AND INCREASING THE PRESSURE GRADIENT
OVER LAKE MICHIGAN. THE COMBINATION OF STRONG COOL WINDS OVER
RELATIVELY MILD WATER MAY SUPPORT OCCASIONAL GALE FORCE
GUSTS TUESDAY...BUT GENERALLY WINDS ARE EXPECTED TO REMAIN IN THE
20 TO 30 KT RANGE. BY WEDNESDAY CONDITIONS BEGIN TO RELAX AGAIN AS
HIGH PRESSURE SPREADS IN FROM THE WEST.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1226 PM CDT Sun Aug 10 2014
.UPDATE...
ISSUED AT 949 AM CDT SUN AUG 10 2014
Showers continue to drift west/northwest across parts of central
and southeast Illinois late this morning, associated with a
trough/shear axis that extends from just north of Lawrenceville to
near Macomb. Heaviest showers since sunrise have been northwest of
the Illinois River, with latest radar images showing the heavier
precipitation now across Stark County. HRRR shows the showers in
that area weakening this morning as the trough becomes more
diffuse, with the greater concentration during the afternoon still
expected closer to the Indiana border. Thunder threat should
mainly be this afternoon across the eastern CWA, as some breaks in
the cloud cover allow the atmosphere along the trough to
destabilize some.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 325 AM CDT SUN AUG 10 2014
A few features to keep an eye on during the next 24 hours with
respect to precipitation risk. The first is a wavy frontal boundary
extending from eastern KY/TN westward into the central plains. Also
of note is a weak trof extending northwest from a very weak surface
low over central KY into central Illinois. This trof/shear axis has
some depth to it, and has been associated with light rain/drizzle
across the forecast area overnight. Another frontal boundary,
oriented northeast to southwest, will slowly approach from the
northwest tonight.
The trof/shear axis across much of the forecast area should continue
to produce a risk of precipitation while it is around today, with a
maximum risk associated with peak diurnal heating. While the details
are unclear, will need to keep an eye on some potential enhancement
that may occur with a possible arrival of a MCV out of plains storm
complex. Then low rain chances will increase again from the west
late tonight with the approach of the front from the northwest.
Have trended forecast cloudier, as there is not a significant
mechanism to scour the clouds currently in the area out. As a
result, have also tweaked the high temperatures down a bit today in
light of the 70s that were seen in many areas yesterday beneath the
cloud cover, and the decent probability that this may occur again
today.
&&
.LONG TERM...(Monday through Sunday)
ISSUED AT 325 AM CDT SUN AUG 10 2014
00Z forecast model suite continues to deepen a strong upper level
trof into the Great Lakes region Monday with surface low pressure
strengthening as it lifts NE into IN and SE lower MI Monday night
while bringing a frontal boundary east of IL by Monday evening. This
will bring a chance of showers and thunderstorms to central and
especially eastern IL Monday and lingering chances near the IN
border til sunset. SPC keeps 5% risk of severe storms south and east
of IL. Highs in the lower 80s Monday with mid 80s near
Lawrenceville. Lows Monday night in the lower 60s, with mid 60s SE
of I-70.
Strong upper level trof over IL and Ohio river valley Tue while
surface low pressure deepens into southeast Ontario Canada. Best
chances of showers and thunderstorms shifts east of IL Tue, and just
have slight chances near the IN border. Highs in the upper 70s Tue
with lower 80s by Lawrenceville. Cooler and less humid air filters
during Tue and Tue night with lows Tue night in the mid to upper 50s.
Dry conditions prevail from Tue night through Thu night as weak
Canadian high pressure around 1020 mb settles into the region Wed
night and Thu. Below normal highs of 75-80F again on Wed and around
80F Thu. Lows Wed night in the upper 50s to near 60F and around 60F
Thu night.
IL gets into a WNW flow aloft late this week with more unsettled
weather pattern evolving Friday into next weekend. Surface high
pressure ridge shifts east of IL by Friday with return southerly
flow by next weekend bringing temps and humidity levels back up.
ECMWF model is slower bringing in next weather system and now keeps
much of central/SE IL dry on Friday while bringing QPF into area Fri
night and Saturday and dry again on Sunday and very warm & humid.
GFS has a wetter solution in extended forecast with qpf overnight
Thu night through Sunday. GEM is dry on Thu night and Friday which
better matches ECMWF model and tended to lean in this direction.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 1225 PM CDT SUN AUG 10 2014
Still some lingering MVFR ceilings near KSPI/KCMI at midday,
although these should be lifting soon. Showers are currently
clear of the TAF sites, but high-resolution model guidance
indicates some development this afternoon as a weak boundary
remains in place over the area. Indeed, some development is now
taking place between KMTO and KHUF, and is lifting slowly
northwest toward KCMI. The afternoon showers should fade out some
with sunset, but additional showers may form overnight as an upper
wave enters Illinois. More widespread shower and thunderstorm
development expected Monday morning with this feature. Have
maintained the MVFR visibilities overnight, with SREF probability
guidance indicating the KSPI-KCMI corridor most likely to see
these lower visibilities.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEELHART
SHORT TERM...BAK
LONG TERM...07
AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1108 AM CDT SUN AUG 10 2014
.DISCUSSION...
1108 AM CDT
HAVE MADE A FEW ADJUSTMENTS TO GRIDS THIS MORNING. ACCOUNTING FOR
MORE ORGANIZED AREA OF SHOWERS LIFTING INTO BENTON AND JASPER THAT
DID HAVE ONE ISOLATED CG LIGHTNING STRIKE IN THE 10AM HOUR...HAVE
BUMPED POPS TO LIKELY/HIGH END CHC IN THAT AREA THROUGH MID DAY.
THIS AREA OF SHOWERS SHOULD TEND TO WEAKEN AS SHORT WAVE/VORT NOTED
ON W/V IMAGERY PASSES OFF TO EAST. THEN THIS AFTERNOON...ANOTHER
WEAK WAVE WILL PUSH ACROSS THE REGION...WITH BETTER FORCING FOR
ASCENT IN PRIMARILY SOUTHERN CWA. NEAR TERM GUIDANCE ALSO KEYING ON
BOUNDARY LAYER CONVERGENCE AS LAKE BREEZE PUSHES INLAND TO FOCUS A
BIT BETTER CHANCE FOR WIDELY SCATTERED SHOWERS INTO THE SOUTHEASTERN
THIRD OF THE CWA. DEWPOINTS IN THE MID AND UPPER 60S AND MINOR
WARMING DESPITE WIDESPREAD CLOUD COVER WILL ENABLE WEAK INSTABILITY
TO DEVELOP...SO HAVE INDICATED ISOLATED TSRA IN THE GRIDS
ALONG/SOUTH OF I-80. WITH THE THICKER CLOUDS IN THE FAR SOUTHEAST
CWA...HAVE SHAVED A FEW DEGREES OFF HIGHS THERE TO THE UPPER 70S TO
AROUND. ELSEWHERE...850/925 MB TEMPS SUPPORT GOING HIGHS IN LOWER
80S...SO ONLY MINOR TWEAKS...THOUGH SPOTS THAT SEE A BIT MORE
SUNSHINE COULD REACH THE MID 80S.
RC
&&
.PREV DISCUSSION...
312 AM CDT
TODAY THROUGH TONIGHT...
BENIGN WEATHER HAS CONTINUED EARLY THIS MORNING WITH A SPRAWLING SFC
RIDGE OF HIGH PRESSURE COVERING MUCH OF THE GREAT LAKES REGION. A
WEAK LOW PRESSURE WAS TRYING TO LIFT NORTH/NORTHEAST ACROSS CENTRAL
TENN. SFC TEMPS HAVE BEEN SLOW TO COOL THIS MORNING...GENERALLY A
RESULT FROM SOME MID-DECK CLOUDS. EXPECT TEMPS TO BOTTOM OUT AROUND
THE MID 60S BY DAYBREAK.
A MID-LVL WAVE OVER SOUTH DAKOTA/NEBRASKA IS PROGGED TO SLIDE
EAST TODAY...AND COULD BRING AN ISOLATED SHOWER/THUNDERSTORM TO THE
FORECAST AREA THIS AFTERNOON...MAINLY SOUTH OF I-80. THIS APPEARS TO
BE MORE DIURNALLY DRIVEN...AND NOT EXPECTING MUCH COVERAGE WITH ANY
PRECIP THAT DEVELOPS THIS AFTERNOON. TEMPS WILL WARM INTO THE LOW
80S FOR MUCH OF THE AREA...THE EXCEPTION WILL BE AREAS ADJACENT TO
LAKE MICHIGAN WITH AN ONSHORE FLOW KEEPING TEMPS IN THE MID/UPR 70S.
PRECIP SHUD STEADILY DIMINISH IN COVERAGE SHORTLY AFTER SUNSET.
GUIDANCE CONTINUES TO PROG CONSIDERABLE MOISTURE THROUGHOUT THE
MID-LVLS SUGGESTIVE OF A MOSTLY CLOUDY NIGHT. THUS EXPECT TEMPS TO
HOLD UP IN THE MID 60S.
MONDAY THROUGH TUESDAY...
STUBBORN SFC RIDGE FINALLY ERODES ENOUGH TO ALLOW A MID-LVL VORT
OVER CENTRAL CANADA TO SLIDE SOUTHEAST ACROSS THE UPPER MIDWEST MON.
GUIDANCE DOES SUGGEST A WEAKER MID-LVL FEATURE WILL TRY TO LIFT
NORTHEAST ACROSS THE OHIO VALLEY MON. WITH SLIGHTLY STRONGER FORCING
AND INCREASED MOISTURE THE BEST TIMING FOR PRECIP APPEARS TO BE IN
THE AFTN/EVE MON HOURS. LAPSE RATES ARE PROGGED TO STEEPEN MON
AFTN...HOWEVER THE COOLER AIR ALOFT DOES NOT ARRIVE UNTIL LATE MON
NGT. THIS COUPLED WITH THE LACK OF GOOD FORCING MON SHUD LIMIT ANY
CONVECTION FROM BECOMING ORGANIZED. HAVE HELD ONTO HIGHS ARND 80 OR
LOW 80S MON...ALTHOUGH WITH CONSIDERABLE CLOUD COVER AND WINDS
LIKELY TURNING NW BY LATE MORNING...TEMPS COULD END UP STRUGGLING TO
WARM BEYOND THE 70S.
TROUGH AXIS PIVOTS EAST TUE...WITH BROAD SFC RIDGING RETURNING TO
THE REGION AND PROVIDING A RETURN TO DRY WEATHER. TEMPS WILL BE MUCH
COOLER TUE WITH THE ARRIVAL OF A 850MB THERMAL TROUGH OF 7 TO 9 DEG
C. THIS COUPLED WITH NORTHERLY WINDS SUGGESTS HIGHS WILL BE IN THE
LOW/MID 70S. SFC RIDGE OVERHEAD TUE NIGHT WILL KEEP P-CLOUDY SKIES
AND ALLOW TEMPS TO RADIATE INTO THE LOW 50S...POSSIBLY THE UPR 40S
IN THE TRADITIONAL COOL SPOTS.
CONFIDENCE...HIGH.
WEDNESDAY THROUGH SATURDAY...
ENSEMBLES CONTINUE TO PROG A RETURN TO THE NORTH ATLANTIC MID-LVL
BLOCK...WHICH INDICATES THE TROUGH OVER THE GREAT LAKES MID-WEEK
WILL LIKELY PERSIST THRU THE END OF THE WEEK. HIGH AMPLITUDE RIDGING
ACROSS THE CANADIAN ROCKIES ALSO SUGGESTS THAT THE SFC RIDGE WILL
LOCK OVERHEAD WITH A DRY NORTHWEST FLOW FOR THE GREAT LAKES REGION.
AT THE UPCOMING WEEKEND APPROACHES SEVERAL ENSEMBLE MEMBERS INDICATE
THE NORTH ATLANTIC BLOCK WILL DISSOLVE AND ALLOW THE TROUGH OVER THE
GREAT LAKES TO KICK EAST AND A SEMI-ZONAL FLOW TO ARRIVE FOR THE MID
SECTIONS OF THE COUNTRY. TEMPS WILL GENERALLY BE IN THE 70S TO ARND
80.
CONFIDENCE...HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* NORTHEAST WINDS 10KT THRU EVENING.
* POSSIBLE LIGHT FOG/MVFR VIS MONDAY MORNING. CMS
//DISCUSSION...UPDATED 16Z...
WINDS HAVE TURNED A BIT MORE NORTH/NORTHEAST IN THE PAST HOUR OR
SO BUT EXPECT WINDS TO REMAIN PREVAILING NORTHEASTERLY THROUGH
SUNSET. SPEEDS ON THE ONE MINUTE DATA AT ORD HAVE BEEN 9KTS FOR
THE PAST HALF HOUR OR SO AND EXPECT PREVAILING SPEEDS AT ORD AND
MDW AT OR JUST ABOVE 10KTS FOR MUCH OF THE AFTERNOON. CMS
PREVIOUS 14Z DISCUSSION...
A FEW SHOWERS EAST OF IKK CONTINUE TO DRIFT NORTHWEST THIS MORNING
AND HI RES GUIDANCE SUGGESTS THIS ACTIVITY WILL PERSIST INTO THIS
AFTERNOON BUT LIKELY REMAIN SOUTH AND SOUTHWEST OF THE TERMINALS.
A FEW SPRINKLES WILL ALSO BE POSSIBLE FURTHER NORTH AS REPORTED AT
IGQ IN THE PAST HOUR. BUT NO MENTION IN THE TAFS WITH EXPECTED
ISOLATED COVERAGE/SHORT DURATION OF ANYTHING THAT DOES DRIFT
FURTHER NORTH. CMS
PREVIOUS 12Z DISCUSSION...
BETWEEN WEAK HIGH PRESSURE JUST TO THE NORTH AND A DEEPENING LOW TO
THE SOUTH...EAST TO NORTHEAST WINDS WILL BE RELATIVELY LIGHT
TODAY...INCREASING TO AROUND 10 KTS THIS AFTERNOON. FLOW AROUND
THE LOW ALSO COULD PRODUCE AN ISOLATED SHOWER...BUT CONFIDENCE IN
TIMING AND LOCATION AND IMPACT REMAINS TOO LOW TO WARRANT MENTION
IN THE TAFS.
TONIGHT THE LOW BEGINS LIFTING FROM INDIANA INTO THE CENTRAL
GREAT LAKES. SOME PATCHY FOG COULD DEVELOP AS WINDS BECOME VERY
LIGHT OVERNIGHT...TURNING NORTH AND EVENTUALLY NORTHWEST.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH FOR WINDS THRU THE PERIOD.
* LOW FOR LIGHT FOG MONDAY MORNING. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...VFR TO MVFR. CHANCE TSRA. NORTH TO NORTHEAST WINDS.
TUESDAY...VFR. CHANCE TSRA. GUSTY NORTH TO NORTHWEST WINDS.
WEDNESDAY...VFR. NORTHWEST WINDS.
THURSDAY...VFR. LIGHT NORTHWEST WINDS EARLY WITH AFTERNOON SHIFT
TO NORTHEAST POSSIBLE WITH LAKE BREEZE.
FRIDAY...VFR. SOUTH TO SOUTHWEST WINDS.
SATURDAY...VFR. EAST WINDS. CHANCE OF THUNDERSTORMS.
LENNING
&&
.MARINE...
319 AM CDT
LOW PRESSURE DEEPENING OVER THE OHIO VALLEY WILL LIFT INTO THE
CENTRAL AND THEN EASTERN GREAT LAKES OVER THE NEXT TWO
DAYS...TURNING WINDS NORTH AND INCREASING THE PRESSURE GRADIENT
OVER LAKE MICHIGAN. THE COMBINATION OF STRONG COOL WINDS OVER
RELATIVELY MILD WATER MAY SUPPORT OCCASIONAL GALE FORCE
GUSTS TUESDAY...BUT GENERALLY WINDS ARE EXPECTED TO REMAIN IN THE
20 TO 30 KT RANGE. BY WEDNESDAY CONDITIONS BEGIN TO RELAX AGAIN AS
HIGH PRESSURE SPREADS IN FROM THE WEST.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
950 AM CDT Sun Aug 10 2014
.UPDATE...
ISSUED AT 949 AM CDT SUN AUG 10 2014
Showers continue to drift west/northwest across parts of central
and southeast Illinois late this morning, associated with a
trough/shear axis that extends from just north of Lawrenceville to
near Macomb. Heaviest showers since sunrise have been northwest of
the Illinois River, with latest radar images showing the heavier
precipitation now across Stark County. HRRR shows the showers in
that area weakening this morning as the trough becomes more
diffuse, with the greater concentration during the afternoon still
expected closer to the Indiana border. Thunder threat should
mainly be this afternoon across the eastern CWA, as some breaks in
the cloud cover allow the atmosphere along the trough to
destabilize some.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 325 AM CDT SUN AUG 10 2014
A few features to keep an eye on during the next 24 hours with
respect to precipitation risk. The first is a wavy frontal boundary
extending from eastern KY/TN westward into the central plains. Also
of note is a weak trof extending northwest from a very weak surface
low over central KY into central Illinois. This trof/shear axis has
some depth to it, and has been associated with light rain/drizzle
across the forecast area overnight. Another frontal boundary,
oriented northeast to southwest, will slowly approach from the
northwest tonight.
The trof/shear axis across much of the forecast area should continue
to produce a risk of precipitation while it is around today, with a
maximum risk associated with peak diurnal heating. While the details
are unclear, will need to keep an eye on some potential enhancement
that may occur with a possible arrival of a MCV out of plains storm
complex. Then low rain chances will increase again from the west
late tonight with the approach of the front from the northwest.
Have trended forecast cloudier, as there is not a significant
mechanism to scour the clouds currently in the area out. As a
result, have also tweaked the high temperatures down a bit today in
light of the 70s that were seen in many areas yesterday beneath the
cloud cover, and the decent probability that this may occur again
today.
&&
.LONG TERM...(Monday through Sunday)
ISSUED AT 325 AM CDT SUN AUG 10 2014
00Z forecast model suite continues to deepen a strong upper level
trof into the Great Lakes region Monday with surface low pressure
strengthening as it lifts NE into IN and SE lower MI Monday night
while bringing a frontal boundary east of IL by Monday evening. This
will bring a chance of showers and thunderstorms to central and
especially eastern IL Monday and lingering chances near the IN
border til sunset. SPC keeps 5% risk of severe storms south and east
of IL. Highs in the lower 80s Monday with mid 80s near
Lawrenceville. Lows Monday night in the lower 60s, with mid 60s SE
of I-70.
Strong upper level trof over IL and Ohio river valley Tue while
surface low pressure deepens into southeast Ontario Canada. Best
chances of showers and thunderstorms shifts east of IL Tue, and just
have slight chances near the IN border. Highs in the upper 70s Tue
with lower 80s by Lawrenceville. Cooler and less humid air filters
during Tue and Tue night with lows Tue night in the mid to upper 50s.
Dry conditions prevail from Tue night through Thu night as weak
Canadian high pressure around 1020 mb settles into the region Wed
night and Thu. Below normal highs of 75-80F again on Wed and around
80F Thu. Lows Wed night in the upper 50s to near 60F and around 60F
Thu night.
IL gets into a WNW flow aloft late this week with more unsettled
weather pattern evolving Friday into next weekend. Surface high
pressure ridge shifts east of IL by Friday with return southerly
flow by next weekend bringing temps and humidity levels back up.
ECMWF model is slower bringing in next weather system and now keeps
much of central/SE IL dry on Friday while bringing QPF into area Fri
night and Saturday and dry again on Sunday and very warm & humid.
GFS has a wetter solution in extended forecast with qpf overnight
Thu night through Sunday. GEM is dry on Thu night and Friday which
better matches ECMWF model and tended to lean in this direction.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
ISSUED AT 659 AM CDT SUN AUG 10 2014
Patchy MVFR conditions to start the day across the central
Illinois, along with isolated showers. Expect VFR conditions to
prevail by midday, with slightly greater coverage of showers and
storms. However, do not have high enough confidence at any one
terminal to go above VCSH mention at this time.
Loss of diurnal heating will reduce precipitation coverage or
bring it to an end for a time tonight. Thinner cloud cover tonight
is apt to allow MVFR fog to develop overnight.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEELHART
SHORT TERM...BAK
LONG TERM...07
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1251 PM CDT SUN AUG 10 2014
.UPDATE...
ISSUED AT 633 AM CDT SUN AUG 10 2014
RADAR TRENDS INDICATE THE FORCING ACROSS CENTRAL ILLINOIS IS
SLOWLY WEAKENING. THUS THE SPRINKLES/VERY LIGHT SHOWERS SHOULD
COME TO AN END WITHIN THE NEXT 1-2 HOURS ACROSS THE FAR
EAST/SOUTHEAST AREAS.
THERE ARE NOW QUESTIONS REGARDING THE POTENTIAL FOR DIURNAL
CONVECTION THIS AFTERNOON. THE FORCING IS QUITE WEAK AND TRENDS
WITH THE RAP HAVE BEEN TO INCREASE THE CONVECTIVE TEMPERATURE. IF
THESE TRENDS CONTINUE...THEN ANY DIURNAL CONVECTION THAT DOES
DEVELOP WOULD BE QUITE ISOLATED.
&&
.SYNOPSIS...
ISSUED AT 306 AM CDT SUN AUG 10 2014
06Z SFC ANALYSIS HAS A SYNOPTIC LOW NEAR KOWB WITH DIFFUSE
BOUNDARIES EXTENDING TO THE EAST AND WEST FROM IT. ACROSS THE PLAINS
THERE WERE NUMEROUS WEAK CONVECTIVE INDUCED LOWS AND HIGHS FROM THE
THUNDERSTORM COMPLEX THAT WAS OVER EASTERN NEBRASKA AND KANSAS. DEW
POINTS WERE IN THE 50S ACROSS THE GREAT LAKES WITH 60S IN THE
PLAINS. DEW POINTS IN THE 70S RAN FROM THE GULF COAST INTO THE
SOUTHERN PLAINS AND LOWER OHIO VALLEY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 306 AM CDT SUN AUG 10 2014
AN UPPER LEVEL DISTURBANCE ACROSS CENTRAL ILLINOIS WAS HELPING TO
GENERATE SPRINKLES AND ISOLATED SHOWERS THAT WERE PUSHING INTO THE
FAR EAST AND SOUTHEAST AREAS. THESE SPRINKLES/ISOLATED LIGHT SHOWERS
WILL CONTINUE THROUGH SUNRISE AND THEN DISSIPATE THROUGH MID MORNING
AS THE FORCING ACROSS ILLINOIS MOVES EAST. DRY CONDITIONS SHOULD
THEN BE SEEN FROM LATE MORNING THROUGH MID DAY.
FORCING ASSOCIATED WITH THE THUNDERSTORM COMPLEX IN THE PLAINS IS
EXPECTED TO INITIATE NEW SHOWERS AND POSSIBLY A FEW THUNDERSTORMS
ACROSS THE FAR WEST AND SOUTH HALF DURING THE AFTERNOON.
TONIGHT ANOTHER WEAK DISTURBANCE WILL MOVE THROUGH THE AREA THAT
SHOULD GENERATE SHOWERS AND A FEW THUNDERSTORMS. ANOTHER
THUNDERSTORM COMPLEX IS EXPECTED TO DEVELOP ACROSS MISSOURI AND
GENERALLY MOVE SOUTHEAST OVERNIGHT. THIS STORM COMPLEX MAY INTERCEPT
THE WEAK INFLOW OF MOISTURE INTO THE AREA AND POTENTIALLY KEEP THE
AREA DRY OVERNIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 306 AM CDT SUN AUG 10 2014
GENERALLY FAVOR THE ECMWF THROUGH THE EXTENDED PERIOD...MAINLY
BECAUSE GFS IS TOO WET.
ON MONDAY...SURFACE COLD FRONT WILL CROSS THE CWFA EARLY MONDAY
MORNING. CHANCE OF POST FRONTAL SHOWERS/TSTORMS WILL INCREASE DURING
THE DAY AS MAIN PIECE OF UPPER ENERGY DROPS INTO THE BASE OF THE
UPPER TROUGH OVER THE GREAT LAKES.
BY TUESDAY...UPPER TROUGH SHIFTS EAST AND SURFACE RIDGE BEGINS TO
BUILD ACROSS IA AND HOLD THROUGH MID WEEK. THUS DRY FORECAST IN STORE
FOR TUESDAY THROUGH THURSDAY.
EARLY THURSDAY...WEAK FRONT SAGS SOUTH INTO AREA. UPPER FORCING LAGS
BEHIND...NOT AFFECTING THE CWFA UNTIL LATE THURSDAY NIGHT INTO
FRIDAY. ECMWF DEPICTS A WARM FRONT LINGERING OVER THE AREA INTO THE
WEEKEND...THUS WILL KEEP CHANCE POPS FRIDAY AND SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1243 PM CDT SUN AUG 10 2014
VFR CONDITIONS EXPECTED THROUGH AT LEAST 11/18Z. MID AND HIGH CLOUDS
WILL INCREASE THROUGH TONIGHT WITH UPPER DISTURBANCE IN MISSOURI PASSING
TO THE SOUTH. ANY CIGS WILL BE AOA 4K AGL AND MOSTLY AOA 10K AGL INTO
LATE MONDAY MORNING. LIGHT EAST WINDS WILL BECOME LIGHT AND VARIABLE
AND SLOWLY SHIFT AND FAVOR THE NORTH AT LESS THAN 5 KTS BY DAYBREAK.
APPROACHING COOL FRONT TO PASS LATE MORNING WITH SHOWERS POSSIBLE
AND HAVE INCLUDED IN TERMINALS AS VICINITY WORDING FOR LATER SHIFTS
TO CLARIFY TIMING AND COVERAGE AS NW WINDS INCREASE BY MID DAY.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...08
SHORT TERM...08
LONG TERM...DMD
AVIATION...NICHOLS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
640 AM CDT SUN AUG 10 2014
.UPDATE...
ISSUED AT 633 AM CDT SUN AUG 10 2014
RADAR TRENDS INDICATE THE FORCING ACROSS CENTRAL ILLINOIS IS
SLOWLY WEAKENING. THUS THE SPRINKLES/VERY LIGHT SHOWERS SHOULD
COME TO AN END WITHIN THE NEXT 1-2 HOURS ACROSS THE FAR
EAST/SOUTHEAST AREAS.
THERE ARE NOW QUESTIONS REGARDING THE POTENTIAL FOR DIURNAL
CONVECTION THIS AFTERNOON. THE FORCING IS QUITE WEAK AND TRENDS
WITH THE RAP HAVE BEEN TO INCREASE THE CONVECTIVE TEMPERATURE. IF
THESE TRENDS CONTINUE...THEN ANY DIURNAL CONVECTION THAT DOES
DEVELOP WOULD BE QUITE ISOLATED.
&&
.SYNOPSIS...
ISSUED AT 306 AM CDT SUN AUG 10 2014
06Z SFC ANALYSIS HAS A SYNOPTIC LOW NEAR KOWB WITH DIFFUSE
BOUNDARIES EXTENDING TO THE EAST AND WEST FROM IT. ACROSS THE PLAINS
THERE WERE NUMEROUS WEAK CONVECTIVE INDUCED LOWS AND HIGHS FROM THE
THUNDERSTORM COMPLEX THAT WAS OVER EASTERN NEBRASKA AND KANSAS. DEW
POINTS WERE IN THE 50S ACROSS THE GREAT LAKES WITH 60S IN THE
PLAINS. DEW POINTS IN THE 70S RAN FROM THE GULF COAST INTO THE
SOUTHERN PLAINS AND LOWER OHIO VALLEY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 306 AM CDT SUN AUG 10 2014
AN UPPER LEVEL DISTURBANCE ACROSS CENTRAL ILLINOIS WAS HELPING TO
GENERATE SPRINKLES AND ISOLATED SHOWERS THAT WERE PUSHING INTO THE
FAR EAST AND SOUTHEAST AREAS. THESE SPRINKLES/ISOLATED LIGHT SHOWERS
WILL CONTINUE THROUGH SUNRISE AND THEN DISSIPATE THROUGH MID MORNING
AS THE FORCING ACROSS ILLINOIS MOVES EAST. DRY CONDITIONS SHOULD
THEN BE SEEN FROM LATE MORNING THROUGH MID DAY.
FORCING ASSOCIATED WITH THE THUNDERSTORM COMPLEX IN THE PLAINS IS
EXPECTED TO INITIATE NEW SHOWERS AND POSSIBLY A FEW THUNDERSTORMS
ACROSS THE FAR WEST AND SOUTH HALF DURING THE AFTERNOON.
TONIGHT ANOTHER WEAK DISTURBANCE WILL MOVE THROUGH THE AREA THAT
SHOULD GENERATE SHOWERS AND A FEW THUNDERSTORMS. ANOTHER
THUNDERSTORM COMPLEX IS EXPECTED TO DEVELOP ACROSS MISSOURI AND
GENERALLY MOVE SOUTHEAST OVERNIGHT. THIS STORM COMPLEX MAY INTERCEPT
THE WEAK INFLOW OF MOISTURE INTO THE AREA AND POTENTIALLY KEEP THE
AREA DRY OVERNIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 306 AM CDT SUN AUG 10 2014
GENERALLY FAVOR THE ECMWF THROUGH THE EXTENDED PERIOD...MAINLY
BECAUSE GFS IS TOO WET.
ON MONDAY...SURFACE COLD FRONT WILL CROSS THE CWFA EARLY MONDAY
MORNING. CHANCE OF POST FRONTAL SHOWERS/TSTORMS WILL INCREASE DURING
THE DAY AS MAIN PIECE OF UPPER ENERGY DROPS INTO THE BASE OF THE
UPPER TROUGH OVER THE GREAT LAKES.
BY TUESDAY...UPPER TROUGH SHIFTS EAST AND SURFACE RIDGE BEGINS TO
BUILD ACROSS IA AND HOLD THROUGH MID WEEK. THUS DRY FORECAST IN STORE
FOR TUESDAY THROUGH THURSDAY.
EARLY THURSDAY...WEAK FRONT SAGS SOUTH INTO AREA. UPPER FORCING LAGS
BEHIND...NOT AFFECTING THE CWFA UNTIL LATE THURSDAY NIGHT INTO
FRIDAY. ECMWF DEPICTS A WARM FRONT LINGERING OVER THE AREA INTO THE
WEEKEND...THUS WILL KEEP CHANCE POPS FRIDAY AND SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 633 AM CDT SUN AUG 10 2014
VFR CONDITIONS ARE EXPECTED THROUGH 06Z/11 BUT SOME VERY PATCHY
MVFR VSBYS WILL BE POSSIBLE THROUGH 14Z/10. VCSH WAS ADDED TO ALL
TAFS AFT 21Z/10 BUT THE PROBABILITY OF A SHRA OR EVEN A TSRA
AFFECTING A TAF SITE IS 10 PERCENT AT BEST. AFT 06Z/11 CONDITIONS
MAY SLOWLY DETERIORATE TO MVFR WITH THE POTENTIAL OF SOME VCSH.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...08
SHORT TERM...08
LONG TERM...DMD
AVIATION...08
AREA FORECAST DISCUSSION
NWS GOODLAND KS
110 PM MDT SUN AUG 10 2014
.UPDATE...
ISSUED AT 534 AM MDT SUN AUG 10 2014
MINOR UPDATE TO SKY/POP/WX TO ADJUST FOR CURRENT CONDITIONS AND
UPSTREAM TRENDS AS SHOWER/THUNDERSTORM ACTIVITY CONTINUES TO MOVE
SOUTH AND EAST ALONG AND BEHIND COLD FRONT. STILL NOT VERY
CONFIDENT ON COVERAGE OVER OUR CWA DUE TO LOW INSTABILITY...AND
BETTER UP-STREAM COVERAGE LIKELY TO MISS OUR CWA BASED ON RADAR
TRENDS. I DECIDED TO KEEP POPS 20 PERCENT...AND ONLY ADJUSTED
TIMING TO ADD MENTION FURTHER SOUTH THIS MORNING.
&&
.SHORT TERM...(THIS MORNING THROUGH TUESDAY NIGHT)
ISSUED AT 238 AM MDT SUN AUG 10 2014
EARLY MORNING WV IMAGERY AND RAP ANALYSIS SHOW WEST-NORTHWEST FLOW
ACROSS THE NORTHERN PLAINS WITH H5 RIDGE BEGINNING TO AMPLIFY INTO
THE WESTERN US...WITH CLOSED LOW OFF THE PACIFIC COAST. OVER THE
PLAINS A SHORTWAVE TROUGH IS MOVING INTO EASTERN NEBRASKA...WITH A
SECOND WEAKER SHORTWAVE JUST UPSTREAM OVER THE NEBRASKA PANHANDLE.
AT THE SURFACE SEVERAL OLD OUTFLOW BOUNDARIES HAVE MOVE OVER THE CWA
WITH WINDS SHIFTING TO THE NORTH. A STATIONARY FRONT IS IN PLACE
ACROSS NORTH CENTRAL KANSAS AND CENTRAL NEBRASKA...WITH A COLD FRONT
NOW DROPPING SOUTH OVER THE WESTERN DAKOTAS INTO NORTHERN NEBRASKA.
MOST THUNDERSTORM ACTIVITY HAS TRANSITIONED EASTWARD WITH A MUCH
MORE STABLE AIR MASS OVER OUR CWA. HRRR CONTINUES TO SHOW
THUNDERSTORM ACTIVITY AHEAD OF COLD FRONT IN NEBRASKA WEAKENING THIS
MORNING BEFORE IT REACHES OUR CWA...HOWEVER WITH SOME WEAK ELEVATED
CAPE IN PLACE AND RADAR TRENDS SHOWING THIS ACTIVITY ALREADY FURTHER
SOUTH...I DECIDED TO KEEP A MENTION OF THUNDER IN THE NORTHERN CWA
THROUGH AROUND 12Z. OTHER CONCERN FOR THIS MORNING WILL BE
FOG/STRATUS. GUIDANCE CONTINUES TO SHOW BL WINDS INCREASING AS A
COLD FRONT DROPS SOUTH THROUGH MID MORNING...AND DESPITE THESE WINDS
LIKELY NOT MIXING TO THE SURFACE THIS MAY BE ENOUGH TO FAVOR STRATUS
OVER FOG. I LEFT PATCHY FOG MENTION IN PLACE.
THUNDERSTORMS MAY DEVELOP OVER THE CWA BY MIDDAY AS DAYTIME HEATING
LEADS TO DESTABILIZATION BEHIND THE COLD FRONT WHICH WILL LIKELY
STALL JUST SW OF THE CWA. TQ INDEX AND MIXED LAYER CAPE ARE BOTH
SUPPORTIVE OF AT LEAST ISOLATED THUNDERSTORM DEVELOPMENT...THOUGH
CONFIDENCE IS LOW AS THE FRONT ITSELF IS LIKELY TO ACT AS THE MAIN
FOCUS FOR ANY THUNDERSTORM INITIATION WITH VERY LITTLE FORCING IN
PLACE THIS AFTERNOON. THIS ACTIVITY SHOULD BE DIURNAL IN NATURE AND
SEVERE PARAMETERS (ESPECIALLY SHEER) ARE UNIMPRESSIVE...SO I AM NOT
ANTICIPATING AN ELEVATED RISK OF SEVERE WEATHER THIS AFTERNOON AND
EVENING.
MONDAY-TUESDAY...WHILE THERE IS A SLIGHT RISK OF THUNDERSTORMS
MONDAY CONFIDENCE IS LOW WITH VERY LITTLE IN THE WAY OF A SIGNAL IN
MOST GUIDANCE. THUNDERSTORMS ARE MOST LIKELY DURING PEAK HEATING
OVER HIGHER TERRAIN IN COLORADO...AND IF THIS WAS TO HAPPEN WESTERLY
0-6KM WINDS MAY CARRY THIS ACTIVITY EAST INTO OUR CWA BEFORE
WEAKENING AFTER SUNSET. BY TUESDAY UPPER LEVEL RIDGE WILL BE MUCH
MORE AMPLIFIED AND EVEN IF THUNDERSTORM ACTIVITY MANAGES TO DEVELOP
IN COLORADO STORM TRACKS ARE NOT FAVORABLE TO BRING ACTIVITY INTO
OUR CWA.
REGARDING TEMPERATURES...WITH COLD FRONT DROPPING SOUTH TODAY AND
COOLER AIR MASS IN PLACE THROUGH MONDAY... TEMPERATURES SHOULD BE
BELOW NORMAL WITH VALUES IN THE MID 80S FOR MOST LOCATIONS (POSSIBLY
EVEN THE LOWER 80S AT A FEW LOCATIONS). WE SHOULD SEE A RETURN TO
SEASONAL NORMALS IN THE UPPER 80S TO AROUND 90F AS THE UPPER LEVEL
RIDGE AMPLIFIES AND BUILDS EASTWARD.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 102 PM MDT SUN AUG 10 2014
UPPER RIDGE CENTERED OVER THE ROCKIES WILL SUPPRESS MOST
CONVECTION THROUGH MID WEEK. CANNOT RULE OUT AN ISOLATED TO WIDELY
SCATTERED STORM UNDER THE RIDGE AS CIN ERODES IN THE
AFTERNOON...BUT SHOULD BE CONFINED MAINLY IN EASTERN COLORADO
WHERE STORMS HAVE A BETTER CHANCE OF MIGRATING OFF THE FRONT
RANGE. BETTER CHANCES FOR PRECIPITATION RETURNS BEGINNING ON
THURSDAY THROUGH THE REMAINDER OF THE LONG TERM PERIOD AS THE
UPPER RIDGE BREAKS DOWN AND A SERIES OF DISTURBANCES MOVES
THROUGH. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL
THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1138 AM MDT SUN AUG 10 2014
VFR CONDITIONS ARE EXPECTED FOR THE NEXT 24 HOURS AT KGLD AND
KMCK AS HIGH PRESSURE RESIDES OVER THE REGION. OTHER THAN SOME
BREEZY NORTH WIND THIS AFTERNOON BEHIND THE FRONT, WINDS WILL BE
LIGHT AND VARIABLE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...DR
SHORT TERM...DR
LONG TERM...024
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1141 AM MDT SUN AUG 10 2014
.UPDATE...
ISSUED AT 534 AM MDT SUN AUG 10 2014
MINOR UPDATE TO SKY/POP/WX TO ADJUST FOR CURRENT CONDITIONS AND
UPSTREAM TRENDS AS SHOWER/THUNDERSTORM ACTIVITY CONTINUES TO MOVE
SOUTH AND EAST ALONG AND BEHIND COLD FRONT. STILL NOT VERY
CONFIDENT ON COVERAGE OVER OUR CWA DUE TO LOW INSTABILITY...AND
BETTER UP-STREAM COVERAGE LIKELY TO MISS OUR CWA BASED ON RADAR
TRENDS. I DECIDED TO KEEP POPS 20 PERCENT...AND ONLY ADJUSTED
TIMING TO ADD MENTION FURTHER SOUTH THIS MORNING.
&&
.SHORT TERM...(THIS MORNING THROUGH TUESDAY NIGHT)
ISSUED AT 238 AM MDT SUN AUG 10 2014
EARLY MORNING WV IMAGERY AND RAP ANALYSIS SHOW WEST-NORTHWEST FLOW
ACROSS THE NORTHERN PLAINS WITH H5 RIDGE BEGINNING TO AMPLIFY INTO
THE WESTERN US...WITH CLOSED LOW OFF THE PACIFIC COAST. OVER THE
PLAINS A SHORTWAVE TROUGH IS MOVING INTO EASTERN NEBRASKA...WITH A
SECOND WEAKER SHORTWAVE JUST UPSTREAM OVER THE NEBRASKA PANHANDLE.
AT THE SURFACE SEVERAL OLD OUTFLOW BOUNDARIES HAVE MOVE OVER THE CWA
WITH WINDS SHIFTING TO THE NORTH. A STATIONARY FRONT IS IN PLACE
ACROSS NORTHCENTRAL KANSAS AND CENTRAL NEBRASKA...WITH A COLD FRONT
NOW DROPPING SOUTH OVER THE WESTERN DAKOTAS INTO NORTHERN NEBRASKA.
MOST THUNDERSTORM ACTIVITY HAS TRANSITIONED EASTWARD WITH A MUCH
MORE STABLE AIR MASS OVER OUR CWA. HRRR CONTINUES TO SHOW
THUNDERSTORM ACTIVITY AHEAD OF COLD FRONT IN NEBRASKA WEAKENING THIS
MORNING BEFORE IT REACHES OUR CWA...HOWEVER WITH SOME WEAK ELEVATED
CAPE IN PLACE AND RADAR TRENDS SHOWING THIS ACTIVITY ALREADY FURTHER
SOUTH...I DECIDED TO KEEP A MENTION OF THUNDER IN THE NORTHERN CWA
THROUGH AROUND 12Z. OTHER CONCERN FOR THIS MORNING WILL BE
FOG/STRATUS. GUIDANCE CONTINUES TO SHOW BL WINDS INCREASING AS A
COLD FRONT DROPS SOUTH THROUGH MID MORNING...AND DESPITE THESE WINDS
LIKELY NOT MIXING TO THE SURFACE THIS MAY BE ENOUGH TO FAVOR STRATUS
OVER FOG. I LEFT PATCHY FOG MENTION IN PLACE.
THUNDERSTORMS MAY DEVELOP OVER THE CWA BY MIDDAY AS DAYTIME HEATING
LEADS TO DESTABILIZATION BEHIND THE COLD FRONT WHICH WILL LIKELY
STALL JUST SW OF THE CWA. TQ INDEX AND MIXED LAYER CAPE ARE BOTH
SUPPORTIVE OF AT LEAST ISOLATED THUNDERSTORM DEVELOPMENT...THOUGH
CONFIDENCE IS LOW AS THE FRONT ITSELF IS LIKELY TO ACT AS THE MAIN
FOCUS FOR ANY THUNDERSTORM INITIATION WITH VERY LITTLE FORCING IN
PLACE THIS AFTERNOON. THIS ACTIVITY SHOULD BE DIURNAL IN NATURE AND
SEVERE PARAMETERS (ESPECIALLY SHEER) ARE UNIMPRESSIVE...SO I AM NOT
ANTICIPATING AN ELEVATED RISK OF SEVERE WEATHER THIS AFTERNOON AND
EVENING.
MONDAY-TUESDAY...WHILE THERE IS A SLIGHT RISK OF THUNDERSTORMS
MONDAY CONFIDENCE IS LOW WITH VERY LITTLE IN THE WAY OF A SIGNAL IN
MOST GUIDANCE. THUNDERSTORMS ARE MOST LIKELY DURING PEAK HEATING
OVER HIGHER TERRAIN IN COLORADO...AND IF THIS WAS TO HAPPEN WESTERLY
0-6KM WINDS MAY CARRY THIS ACTIVITY EAST INTO OUR CWA BEFORE
WEAKENING AFTER SUNSET. BY TUESDAY UPPER LEVEL RIDGE WILL BE MUCH
MORE AMPLIFIED AND EVEN IF THUNDERSTORM ACTIVITY MANAGES TO DEVELOP
IN COLORADO STORM TRACKS ARE NOT FAVORABLE TO BRING ACTIVITY INTO
OUR CWA.
REGARDING TEMPERATURES...WITH COLD FRONT DROPPING SOUTH TODAY AND
COOLER AIR MASS IN PLACE THROUGH MONDAY... TEMPERATURES SHOULD BE
BELOW NORMAL WITH VALUES IN THE MID 80S FOR MOST LOCATIONS (POSSIBLY
EVEN THE LOWER 80S AT A FEW LOCATIONS). WE SHOULD SEE A RETURN TO
SEASONAL NORMALS IN THE UPPER 80S TO AROUND 90F AS THE UPPER LEVEL
RIDGE AMPLIFIES AND BUILDS EASTWARD.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 238 AM MDT SUN AUG 10 2014
IN THE EXTENDED...MEDIUM RANGE MODELS CONTINUE TO INDICATE LARGE
H5 RIDGE WILL BE IN PLACE ACROSS THE AREA THROUGH THE START OF
THE PERIOD. HOWEVER...MODEL AGREEMENT BREAKS DOWN FAIRLY QUICKLY
WITH RESPECT TO THE FLATTENING OF THIS RIDGE WITH ECMWF/GEM
FLATTENING RIDGE MUCH QUICKER THAN GFS OR GEFS DATA. CONFIDENCE
FAIRLY LOW AS WEEKEND APPROACHES DUE TO THIS AND THINK KEEPING
MIDDLE OF THE ROAD FORECAST MOST PRUDENT THING TO DO AT THIS TIME.
TEMPS WILL BE SEASONABLE WITH AT LEAST A FEW CHANCES OF
THUNDERSTORMS THROUGHOUT THE EXTENDED PERIODS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1138 AM MDT SUN AUG 10 2014
VFR CONDITIONS ARE EXPECTED FOR THE NEXT 24 HOURS AT KGLD AND
KMCK AS HIGH PRESSURE RESIDES OVER THE REGION. OTHER THAN SOME
BREEZY NORTH WIND THIS AFTERNOON BEHIND THE FRONT, WINDS WILL BE
LIGHT AND VARIABLE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...DR
SHORT TERM...DR
LONG TERM...JRM
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
534 AM MDT SUN AUG 10 2014
.UPDATE...
ISSUED AT 534 AM MDT SUN AUG 10 2014
MINOR UPDATE TO SKY/POP/WX TO ADJUST FOR CURRENT CONDITIONS AND
UPSTREAM TRENDS AS SHOWER/THUNDERSTORM ACTIVITY CONTINUES TO MOVE
SOUTH AND EAST ALONG AND BEHIND COLD FRONT. STILL NOT VERY
CONFIDENT ON COVERAGE OVER OUR CWA DUE TO LOW INSTABILITY...AND
BETTER UP-STREAM COVERAGE LIKELY TO MISS OUR CWA BASED ON RADAR
TRENDS. I DECIDED TO KEEP POPS 20 PERCENT...AND ONLY ADJUSTED
TIMING TO ADD MENTION FURTHER SOUTH THIS MORNING.
&&
.SHORT TERM...(THIS MORNING THROUGH TUESDAY NIGHT)
ISSUED AT 238 AM MDT SUN AUG 10 2014
EARLY MORNING WV IMAGERY AND RAP ANALYSIS SHOW WEST-NORTHWEST FLOW
ACROSS THE NORTHERN PLAINS WITH H5 RIDGE BEGINNING TO AMPLIFY INTO
THE WESTERN US...WITH CLOSED LOW OFF THE PACIFIC COAST. OVER THE
PLAINS A SHORTWAVE TROUGH IS MOVING INTO EASTERN NEBRASKA...WITH A
SECOND WEAKER SHORTWAVE JUST UPSTREAM OVER THE NEBRASKA PANHANDLE.
AT THE SURFACE SEVERAL OLD OUTFLOW BOUNDARIES HAVE MOVE OVER THE CWA
WITH WINDS SHIFTING TO THE NORTH. A STATIONARY FRONT IS IN PLACE
ACROSS NORTHCENTRAL KANSAS AND CENTRAL NEBRASKA...WITH A COLD FRONT
NOW DROPPING SOUTH OVER THE WESTERN DAKOTAS INTO NORTHERN NEBRASKA.
MOST THUNDERSTORM ACTIVITY HAS TRANSITIONED EASTWARD WITH A MUCH
MORE STABLE AIR MASS OVER OUR CWA. HRRR CONTINUES TO SHOW
THUNDERSTORM ACTIVITY AHEAD OF COLD FRONT IN NEBRASKA WEAKENING THIS
MORNING BEFORE IT REACHES OUR CWA...HOWEVER WITH SOME WEAK ELEVATED
CAPE IN PLACE AND RADAR TRENDS SHOWING THIS ACTIVITY ALREADY FURTHER
SOUTH...I DECIDED TO KEEP A MENTION OF THUNDER IN THE NORTHERN CWA
THROUGH AROUND 12Z. OTHER CONCERN FOR THIS MORNING WILL BE
FOG/STRATUS. GUIDANCE CONTINUES TO SHOW BL WINDS INCREASING AS A
COLD FRONT DROPS SOUTH THROUGH MID MORNING...AND DESPITE THESE WINDS
LIKELY NOT MIXING TO THE SURFACE THIS MAY BE ENOUGH TO FAVOR STRATUS
OVER FOG. I LEFT PATCHY FOG MENTION IN PLACE.
THUNDERSTORMS MAY DEVELOP OVER THE CWA BY MIDDAY AS DAYTIME HEATING
LEADS TO DESTABILIZATION BEHIND THE COLD FRONT WHICH WILL LIKELY
STALL JUST SW OF THE CWA. TQ INDEX AND MIXED LAYER CAPE ARE BOTH
SUPPORTIVE OF AT LEAST ISOLATED THUNDERSTORM DEVELOPMENT...THOUGH
CONFIDENCE IS LOW AS THE FRONT ITSELF IS LIKELY TO ACT AS THE MAIN
FOCUS FOR ANY THUNDERSTORM INITIATION WITH VERY LITTLE FORCING IN
PLACE THIS AFTERNOON. THIS ACTIVITY SHOULD BE DIURNAL IN NATURE AND
SEVERE PARAMETERS (ESPECIALLY SHEER) ARE UNIMPRESSIVE...SO I AM NOT
ANTICIPATING AN ELEVATED RISK OF SEVERE WEATHER THIS AFTERNOON AND
EVENING.
MONDAY-TUESDAY...WHILE THERE IS A SLIGHT RISK OF THUNDERSTORMS
MONDAY CONFIDENCE IS LOW WITH VERY LITTLE IN THE WAY OF A SIGNAL IN
MOST GUIDANCE. THUNDERSTORMS ARE MOST LIKELY DURING PEAK HEATING
OVER HIGHER TERRAIN IN COLORADO...AND IF THIS WAS TO HAPPEN WESTERLY
0-6KM WINDS MAY CARRY THIS ACTIVITY EAST INTO OUR CWA BEFORE
WEAKENING AFTER SUNSET. BY TUESDAY UPPER LEVEL RIDGE WILL BE MUCH
MORE AMPLIFIED AND EVEN IF THUNDERSTORM ACTIVITY MANAGES TO DEVELOP
IN COLORADO STORM TRACKS ARE NOT FAVORABLE TO BRING ACTIVITY INTO
OUR CWA.
REGARDING TEMPERATURES...WITH COLD FRONT DROPPING SOUTH TODAY AND
COOLER AIR MASS IN PLACE THROUGH MONDAY... TEMPERATURES SHOULD BE
BELOW NORMAL WITH VALUES IN THE MID 80S FOR MOST LOCATIONS (POSSIBLY
EVEN THE LOWER 80S AT A FEW LOCATIONS). WE SHOULD SEE A RETURN TO
SEASONAL NORMALS IN THE UPPER 80S TO AROUND 90F AS THE UPPER LEVEL
RIDGE AMPLIFIES AND BUILDS EASTWARD.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 238 AM MDT SUN AUG 10 2014
IN THE EXTENDED...MEDIUM RANGE MODELS CONTINUE TO INDICATE LARGE
H5 RIDGE WILL BE IN PLACE ACROSS THE AREA THROUGH THE START OF
THE PERIOD. HOWEVER...MODEL AGREEMENT BREAKS DOWN FAIRLY QUICKLY
WITH RESPECT TO THE FLATTENING OF THIS RIDGE WITH ECMWF/GEM
FLATTENING RIDGE MUCH QUICKER THAN GFS OR GEFS DATA. CONFIDENCE
FAIRLY LOW AS WEEKEND APPROACHES DUE TO THIS AND THINK KEEPING
MIDDLE OF THE ROAD FORECAST MOST PRUDENT THING TO DO AT THIS TIME.
TEMPS WILL BE SEASONABLE WITH AT LEAST A FEW CHANCES OF
THUNDERSTORMS THROUGHOUT THE EXTENDED PERIODS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 517 AM MDT SUN AUG 10 2014
A LOT OF UNCERTAINTY REGARDING FLIGHT CONDITIONS DURING THE
MORNING. SHORT RANGE GUIDANCE CONTINUES TO INDICATE POSSIBLE
STRATUS DEVELOPMENT...THOUGH HAS BACKED OFF ON FOG POTENTIAL. THERE
HAVE BEEN A FEW POCKETS OF 1000-1500 FT CLOUDS HOWEVER THIS HAS
GENERALLY REMAINED ISOLATED AND TRANSITIONAL. I HAVE DECIDE TO
KEEP TAFS AT KGLD AND KMCK VFR FOR NOW...HOWEVER WITH MOIST BL
CONDITIONS I COULDNT COMPLETELY RULE OUT CIGS/FOG TO MVFR...MAYBE
EVEN IFR. AS A FRONT DROPS SOUTH OVER BOTH TERMINALS SHOWERS OR
THUNDERSTORMS MAY MOVE WITHIN THE VICINITY OF KMCK AND DEVELOP
NEAR THE KGLD TERMINAL. BASED ON RADAR AND SHORT RANGE GUIDANCE
CONFIDENCE IS CURRENTLY HIGHER FOR THIS ACTIVITY REACHING
KMCK...SO I INTRODUCED A VCTS GROUP. CONFIDENCE IS NOT AS HIGH AT
KGLD AND IF THIS ACTIVITY DOES REACH KGLD IT MAY BE VERY ISOLATED
IN NATURE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...DR
SHORT TERM...DR
LONG TERM...JRM
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
518 AM MDT SUN AUG 10 2014
.SHORT TERM...(THIS MORNING THROUGH TUESDAY NIGHT)
ISSUED AT 238 AM MDT SUN AUG 10 2014
EARLY MORNING WV IMAGERY AND RAP ANALYSIS SHOW WEST-NORTHWEST FLOW
ACROSS THE NORTHERN PLAINS WITH H5 RIDGE BEGINNING TO AMPLIFY INTO
THE WESTERN US...WITH CLOSED LOW OFF THE PACIFIC COAST. OVER THE
PLAINS A SHORTWAVE TROUGH IS MOVING INTO EASTERN NEBRASKA...WITH A
SECOND WEAKER SHORTWAVE JUST UPSTREAM OVER THE NEBRASKA PANHANDLE.
AT THE SURFACE SEVERAL OLD OUTFLOW BOUNDARIES HAVE MOVE OVER THE CWA
WITH WINDS SHIFTING TO THE NORTH. A STATIONARY FRONT IS IN PLACE
ACROSS NORTHCENTRAL KANSAS AND CENTRAL NEBRASKA...WITH A COLD FRONT
NOW DROPPING SOUTH OVER THE WESTERN DAKOTAS INTO NORTHERN NEBRASKA.
MOST THUNDERSTORM ACTIVITY HAS TRANSITIONED EASTWARD WITH A MUCH
MORE STABLE AIR MASS OVER OUR CWA. HRRR CONTINUES TO SHOW
THUNDERSTORM ACTIVITY AHEAD OF COLD FRONT IN NEBRASKA WEAKENING THIS
MORNING BEFORE IT REACHES OUR CWA...HOWEVER WITH SOME WEAK ELEVATED
CAPE IN PLACE AND RADAR TRENDS SHOWING THIS ACTIVITY ALREADY FURTHER
SOUTH...I DECIDED TO KEEP A MENTION OF THUNDER IN THE NORTHERN CWA
THROUGH AROUND 12Z. OTHER CONCERN FOR THIS MORNING WILL BE
FOG/STRATUS. GUIDANCE CONTINUES TO SHOW BL WINDS INCREASING AS A
COLD FRONT DROPS SOUTH THROUGH MID MORNING...AND DESPITE THESE WINDS
LIKELY NOT MIXING TO THE SURFACE THIS MAY BE ENOUGH TO FAVOR STRATUS
OVER FOG. I LEFT PATCHY FOG MENTION IN PLACE.
THUNDERSTORMS MAY DEVELOP OVER THE CWA BY MIDDAY AS DAYTIME HEATING
LEADS TO DESTABILIZATION BEHIND THE COLD FRONT WHICH WILL LIKELY
STALL JUST SW OF THE CWA. TQ INDEX AND MIXED LAYER CAPE ARE BOTH
SUPPORTIVE OF AT LEAST ISOLATED THUNDERSTORM DEVELOPMENT...THOUGH
CONFIDENCE IS LOW AS THE FRONT ITSELF IS LIKELY TO ACT AS THE MAIN
FOCUS FOR ANY THUNDERSTORM INITIATION WITH VERY LITTLE FORCING IN
PLACE THIS AFTERNOON. THIS ACTIVITY SHOULD BE DIURNAL IN NATURE AND
SEVERE PARAMETERS (ESPECIALLY SHEER) ARE UNIMPRESSIVE...SO I AM NOT
ANTICIPATING AN ELEVATED RISK OF SEVERE WEATHER THIS AFTERNOON AND
EVENING.
MONDAY-TUESDAY...WHILE THERE IS A SLIGHT RISK OF THUNDERSTORMS
MONDAY CONFIDENCE IS LOW WITH VERY LITTLE IN THE WAY OF A SIGNAL IN
MOST GUIDANCE. THUNDERSTORMS ARE MOST LIKELY DURING PEAK HEATING
OVER HIGHER TERRAIN IN COLORADO...AND IF THIS WAS TO HAPPEN WESTERLY
0-6KM WINDS MAY CARRY THIS ACTIVITY EAST INTO OUR CWA BEFORE
WEAKENING AFTER SUNSET. BY TUESDAY UPPER LEVEL RIDGE WILL BE MUCH
MORE AMPLIFIED AND EVEN IF THUNDERSTORM ACTIVITY MANAGES TO DEVELOP
IN COLORADO STORM TRACKS ARE NOT FAVORABLE TO BRING ACTIVITY INTO
OUR CWA.
REGARDING TEMPERATURES...WITH COLD FRONT DROPPING SOUTH TODAY AND
COOLER AIR MASS IN PLACE THROUGH MONDAY... TEMPERATURES SHOULD BE
BELOW NORMAL WITH VALUES IN THE MID 80S FOR MOST LOCATIONS (POSSIBLY
EVEN THE LOWER 80S AT A FEW LOCATIONS). WE SHOULD SEE A RETURN TO
SEASONAL NORMALS IN THE UPPER 80S TO AROUND 90F AS THE UPPER LEVEL
RIDGE AMPLIFIES AND BUILDS EASTWARD.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 238 AM MDT SUN AUG 10 2014
IN THE EXTENDED...MEDIUM RANGE MODELS CONTINUE TO INDICATE LARGE
H5 RIDGE WILL BE IN PLACE ACROSS THE AREA THROUGH THE START OF
THE PERIOD. HOWEVER...MODEL AGREEMENT BREAKS DOWN FAIRLY QUICKLY
WITH RESPECT TO THE FLATTENING OF THIS RIDGE WITH ECMWF/GEM
FLATTENING RIDGE MUCH QUICKER THAN GFS OR GEFS DATA. CONFIDENCE
FAIRLY LOW AS WEEKEND APPROACHES DUE TO THIS AND THINK KEEPING
MIDDLE OF THE ROAD FORECAST MOST PRUDENT THING TO DO AT THIS TIME.
TEMPS WILL BE SEASONABLE WITH AT LEAST A FEW CHANCES OF
THUNDERSTORMS THROUGHOUT THE EXTENDED PERIODS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 517 AM MDT SUN AUG 10 2014
A LOT OF UNCERTAINTY REGARDING FLIGHT CONDITIONS DURING THE
MORNING. SHORT RANGE GUIDANCE CONTINUES TO INDICATE POSSIBLE
STRATUS DEVELOPMENT...THOUGH HAS BACKED OFF ON FOG POTENTIAL. THERE
HAVE BEEN A FEW POCKETS OF 1000-1500 FT CLOUDS HOWEVER THIS HAS
GENERALLY REMAINED ISOLATED AND TRANSITIONAL. I HAVE DECIDE TO
KEEP TAFS AT KGLD AND KMCK VFR FOR NOW...HOWEVER WITH MOIST BL
CONDITIONS I COULDNT COMPLETELY RULE OUT CIGS/FOG TO MVFR...MAYBE
EVEN IFR. AS A FRONT DROPS SOUTH OVER BOTH TERMINALS SHOWERS OR
THUNDERSTORMS MAY MOVE WITHIN THE VICINITY OF KMCK AND DEVELOP
NEAR THE KGLD TERMINAL. BASED ON RADAR AND SHORT RANGE GUIDANCE
CONFIDENCE IS CURRENTLY HIGHER FOR THIS ACTIVITY REACHING
KMCK...SO I INTRODUCED A VCTS GROUP. CONFIDENCE IS NOT AS HIGH AT
KGLD AND IF THIS ACTIVITY DOES REACH KGLD IT MAY BE VERY ISOLATED
IN NATURE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JRM
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
239 AM MDT SUN AUG 10 2014
.SHORT TERM...(THIS MORNING THROUGH TUESDAY NIGHT)
ISSUED AT 238 AM MDT SUN AUG 10 2014
EARLY MORNING WV IMAGERY AND RAP ANALYSIS SHOW WEST-NORTHWEST FLOW
ACROSS THE NORTHERN PLAINS WITH H5 RIDGE BEGINNING TO AMPLIFY INTO
THE WESTERN US...WITH CLOSED LOW OFF THE PACIFIC COAST. OVER THE
PLAINS A SHORTWAVE TROUGH IS MOVING INTO EASTERN NEBRASKA...WITH A
SECOND WEAKER SHORTWAVE JUST UPSTREAM OVER THE NEBRASKA PANHANDLE.
AT THE SURFACE SEVERAL OLD OUTFLOW BOUNDARIES HAVE MOVE OVER THE CWA
WITH WINDS SHIFTING TO THE NORTH. A STATIONARY FRONT IS IN PLACE
ACROSS NORTHCENTRAL KANSAS AND CENTRAL NEBRASKA...WITH A COLD FRONT
NOW DROPPING SOUTH OVER THE WESTERN DAKOTAS INTO NORTHERN NEBRASKA.
MOST THUNDERSTORM ACTIVITY HAS TRANSITIONED EASTWARD WITH A MUCH
MORE STABLE AIR MASS OVER OUR CWA. HRRR CONTINUES TO SHOW
THUNDERSTORM ACTIVITY AHEAD OF COLD FRONT IN NEBRASKA WEAKENING THIS
MORNING BEFORE IT REACHES OUR CWA...HOWEVER WITH SOME WEAK ELEVATED
CAPE IN PLACE AND RADAR TRENDS SHOWING THIS ACTIVITY ALREADY FURTHER
SOUTH...I DECIDED TO KEEP A MENTION OF THUNDER IN THE NORTHERN CWA
THROUGH AROUND 12Z. OTHER CONCERN FOR THIS MORNING WILL BE
FOG/STRATUS. GUIDANCE CONTINUES TO SHOW BL WINDS INCREASING AS A
COLD FRONT DROPS SOUTH THROUGH MID MORNING...AND DESPITE THESE WINDS
LIKELY NOT MIXING TO THE SURFACE THIS MAY BE ENOUGH TO FAVOR STRATUS
OVER FOG. I LEFT PATCHY FOG MENTION IN PLACE.
THUNDERSTORMS MAY DEVELOP OVER THE CWA BY MIDDAY AS DAYTIME HEATING
LEADS TO DESTABILIZATION BEHIND THE COLD FRONT WHICH WILL LIKELY
STALL JUST SW OF THE CWA. TQ INDEX AND MIXED LAYER CAPE ARE BOTH
SUPPORTIVE OF AT LEAST ISOLATED THUNDERSTORM DEVELOPMENT...THOUGH
CONFIDENCE IS LOW AS THE FRONT ITSELF IS LIKELY TO ACT AS THE MAIN
FOCUS FOR ANY THUNDERSTORM INITIATION WITH VERY LITTLE FORCING IN
PLACE THIS AFTERNOON. THIS ACTIVITY SHOULD BE DIURNAL IN NATURE AND
SEVERE PARAMETERS (ESPECIALLY SHEER) ARE UNIMPRESSIVE...SO I AM NOT
ANTICIPATING AN ELEVATED RISK OF SEVERE WEATHER THIS AFTERNOON AND
EVENING.
MONDAY-TUESDAY...WHILE THERE IS A SLIGHT RISK OF THUNDERSTORMS
MONDAY CONFIDENCE IS LOW WITH VERY LITTLE IN THE WAY OF A SIGNAL IN
MOST GUIDANCE. THUNDERSTORMS ARE MOST LIKELY DURING PEAK HEATING
OVER HIGHER TERRAIN IN COLORADO...AND IF THIS WAS TO HAPPEN WESTERLY
0-6KM WINDS MAY CARRY THIS ACTIVITY EAST INTO OUR CWA BEFORE
WEAKENING AFTER SUNSET. BY TUESDAY UPPER LEVEL RIDGE WILL BE MUCH
MORE AMPLIFIED AND EVEN IF THUNDERSTORM ACTIVITY MANAGES TO DEVELOP
IN COLORADO STORM TRACKS ARE NOT FAVORABLE TO BRING ACTIVITY INTO
OUR CWA.
REGARDING TEMPERATURES...WITH COLD FRONT DROPPING SOUTH TODAY AND
COOLER AIR MASS IN PLACE THROUGH MONDAY... TEMPERATURES SHOULD BE
BELOW NORMAL WITH VALUES IN THE MID 80S FOR MOST LOCATIONS (POSSIBLY
EVEN THE LOWER 80S AT A FEW LOCATIONS). WE SHOULD SEE A RETURN TO
SEASONAL NORMALS IN THE UPPER 80S TO AROUND 90F AS THE UPPER LEVEL
RIDGE AMPLIFIES AND BUILDS EASTWARD.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 238 AM MDT SUN AUG 10 2014
IN THE EXTENDED...MEDIUM RANGE MODELS CONTINUE TO INDICATE LARGE
H5 RIDGE WILL BE IN PLACE ACROSS THE AREA THROUGH THE START OF
THE PERIOD. HOWEVER...MODEL AGREEMENT BREAKS DOWN FAIRLY QUICKLY
WITH RESPECT TO THE FLATTENING OF THIS RIDGE WITH ECMWF/GEM
FLATTENING RIDGE MUCH QUICKER THAN GFS OR GEFS DATA. CONFIDENCE
FAIRLY LOW AS WEEKEND APPROACHES DUE TO THIS AND THINK KEEPING
MIDDLE OF THE ROAD FORECAST MOST PRUDENT THING TO DO AT THIS TIME.
TEMPS WILL BE SEASONABLE WITH AT LEAST A FEW CHANCES OF
THUNDERSTORMS THROUGHOUT THE EXTENDED PERIODS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1157 PM MDT SAT AUG 9 2014
SHOWERS/STORMS HAVE EXITED THE REGION AND NO ADDITIONAL ACTIVITY
ANTICIPATED TONIGHT. COLD FRONT...ENHANCED BY OUTFLOW...HAS PASSED
THROUGH WITH NORTHEAST WINDS AT SITES. WINDS SHOULD BACK TO NORTH
LATER TONIGHT. STILL BELIEVE AS TEMPS COOL...FOG AND STRATUS
SHOULD DEVELOP. MODEL GUIDANCE HAS BACKED OFF GUIDANCE BUT THINK
THEY ARE DOWNPLAYING THE HEAVY RAINS THIS EVENING ON TOP OF
CURRENT BOUNDARY LAYER MOISTURE. FOG/STATUS DEVELOPS AFTER 09Z AND
DISSIPATES BY 15Z. FORECAST FOR SHOWERS/STORMS IS SOMEWHAT IN
DOUBT TOMORROW WITH THE MAJORITY OF THE ACTIVITY WELL TO THE EAST
OF TAF SITES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JRM
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS WICHITA KS
1210 AM CDT SUN AUG 10 2014
.UPDATE...
ISSUED AT 725 PM CDT SAT AUG 9 2014
UPDATED FORECAST NO DOUBT PROMPTED PRIMARILY BY ISSUANCE OF SEVERE
THUNDERSTORM WATCH #458 THAT IS IN EFFECT UNTIL 2 AM FOR ALL OF
CENTRAL KS AS WELL AS RENO COUNTY. ALSO FINE-TUNED POPS & ASSOCIATED
WEATHER & QPF GRIDS TO BETTER ALIGN WITH ANTICIPATED SHORT-TERM
TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 322 PM CDT SAT AUG 9 2014
TON-SUN: MESOSCALE AGAIN COMPLICATING WHEN AND WHERE CONVECTION WILL
REDEVELOP THIS EVENING. BOUNDARY THAT LINGERS FROM CONVECTION THAT
MOVED INTO AND DISSIPATED ACROSS NORTH CENTRAL KANSAS OVERNIGHT
APPEARS TO BE A POSSIBLE FOCUS FOR LATE AFTERNOON AND EARLY EVENING
CONVECTION. RUC HAS BEEN CONSISTENT IN DEVELOPING WEAK...DIURNALLY
DRIVEN CONVECTION FROM KEMP TO KCNK BETWEEN 22-23 UTC AND ADVECTING IT
WEST SOUTHWEST INTO CENTRAL KANSAS. AT PRESENT...UNSURE HOW THIS
CONVECTION WILL INTERPLAY WITH CONVECTION THAT SYNOPTIC/MESO MODELS
BEGIN TO DEVELOP ALONG WEAK SYNOPTIC BOUNDARY ACROSS WESTERN KANSAS
DURING THE EVENING HOURS...DUE TO INCREASING SYNOPTIC SCALE FORCING. A
LARGE VORTEX WILL MOVE ACROSS CENTRAL CANADA DURING THE NEXT 48 HOURS.
LARGE SCALE LIFT ACROSS KANSAS WILL INCREASE THIS EVENING IN RESPONSE
TO COMPACT SHORT WAVE THAT SKIRTS THE SOUTHERN PERIPHERY OF LARGE
VORTEX...AND JET STREAK MOVING NORTHEAST OUT OF NEW MEXICO AND ACROSS
KANSAS. OPERATIONAL SYNOPTIC MESOSCALE MODELS ARE SHOWING QUITE A BIT
OF VARIANCE IN TIMING AND COVERAGE OF OVERNIGHT STORMS...FOR TIME
BEING DECIDED TO USE SREF/SSEO AS GUIDE FOR TIMING AND COVERAGE WHICH
BOTH ACCOUNT FOR SPREAD OF SOLUTIONS. MESOSCALE FORCING WILL DICTATE
PARTICULARS OF CONVECTIONS TRACK...HOWEVER EXPECT ACTIVITY TO BE
SUSTAINED THROUGH MOST OF THE DAY SUNDAY DUE TO SLOW MOVEMENT OF LARGE
SCALE VORTEX MOVING ACROSS CENTRAL CANADA. AS BROADSCALE SUBSIDENCE
OVERSPREADS REGION SUNDAY EVENING...EXPECT BULK OF THE ACTIVITY TO
DISSIPATE OR MOVE EAST OF CWA BY 00 UTC ON MONDAY. TEMPERATURES
TONIGHT AND SUNDAY WILL BE DEPENDENT ON PRECIPITATION...WITH GUIDANCE
LOOKING REASONABLE.
MON-TUES: ANOTHER PERIOD OF DRY AND COOLER THAN NORMAL CONDITIONS. AS
UPPER VORTEX MOVES INTO EASTERN CANADA...WEAK RIDGING THAT HAS BEEN
LINGERING OVER PLAINS RETROGRADES WEST. THIS WILL ALLOW COOLER AIRMASS
TO OVERSPREAD AREA...WITH HIGH AND LOW TEMPERATURES AVERAGING 5 TO 10
DEGREES BELOW NORMAL FOR EARLY AUGUST.
SF
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 322 PM CDT SAT AUG 9 2014
COOLER THAN NORMAL AND DRY CONDITIONS WILL LINGER THROUGH
WEDNESDAY...BUT RETURN TO MORE TYPICAL AUGUST WEATHER RETURNS BY
LATE IN THE WEEK. AS EASTERN CANADA/U.S. VORTEX MOVES INTO THE
MARITIME REGION...UPPER RIDGING BEGINS TO BUILD BACK INTO CENTRAL
PLAINS. BY LATE IN THE WEEK...EXPECT TEMPERATURES TO REBOUND
CLOSER TO NORMAL. KANSAS/CWA WILL REMAIN ON CYCLONIC SHEAR
SIDE...SETTING THE STAGE FOR POSSIBLE NOCTURNAL MCS ACTIVITY.
GEFS/OPERATIONAL MED-RANGE MODELS HIGHLIGHTING THE BEST CHANCES
FOR CONVECTION TO OCCUR THURSDAY AND FRIDAY NIGHT.
SF
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1210 AM CDT SUN AUG 10 2014
NUMEROUS (+)TSRA CONT TO SPREAD E ACRS CNTRL KS WHERE ~35KT GUSTS ARE
LIKELY TIL 06Z. (+)TSRA CURVE SW TOWARD SW KS WITH TSRA SPREADING E
ACRS ALL OF SC KS THRU 10Z WHERE/WHEN 3-4SM VSBYS ARE LIKELY. A 2ND
CONCERN IS THE POTENTIAL FOR ~1500FT CIGS OVER KHUT & KICT FROM 12-15Z.
HAVE PLACED BOTH TERMINALS IN MVFR CIG STATUS DURING THIS PERIOD BUT
CIGS SHOULD LIFT QUICKLY WITH BOTH TERMINALS RETURNING TO VFR STATUS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 68 87 63 86 / 20 10 10 10
HUTCHINSON 67 87 62 86 / 20 10 10 10
NEWTON 67 86 62 85 / 20 10 10 10
ELDORADO 67 86 62 85 / 20 10 10 10
WINFIELD-KWLD 69 87 65 87 / 30 10 10 10
RUSSELL 65 85 61 86 / 10 10 10 10
GREAT BEND 66 85 61 86 / 10 10 10 10
SALINA 66 87 62 86 / 20 10 10 10
MCPHERSON 67 87 62 85 / 20 10 10 10
COFFEYVILLE 69 88 66 87 / 40 10 10 10
CHANUTE 68 86 63 84 / 40 10 10 10
IOLA 68 85 63 84 / 40 10 10 10
PARSONS-KPPF 69 87 65 85 / 40 10 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
ES
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
946 PM EDT Mon Aug 11 2014
...Forecast Update...
Issued at 945 PM EDT Mon Aug 11 2014
Have one more significant cell in the middle of the forecast area,
which developed along a theta-e ridge and just ahead of weak PV
anomaly. May yet see a few more spots develop east of the I-65
corridor the next couple of hours, but coverage will be limited by
loss of heating. Latest RUC bumps ahead the timing of some showers
moving in for daybreak tomorrow so have added this into the forecast
as well as put in patchy fog, given weak surface flow and the rains
that fell today.
Issued at 730 PM EDT Mon Aug 11 2014
Cold front is right along the Ohio River this hour and forecast to
continue sagging slowly south. Still expect a secondary front to
move through the region Tuesday, so cannot rule out additional
showers toward daybreak over the north. Till then, we still have
banded precipitation to deal with, torrential at times. Most cells
have been progressive today, but over the last hour some training of
storms has occurred over parts of the Bluegrass. With the loss of
heating, expect our convection to weaken significantly. Updated the
forecast to bring grids closer to current observations.
.SHORT TERM (Now through Tuesday Night)...
Issued at 257 PM EDT Mon Aug 11 2014
We will have one more day of unsettled weather before drier and
cooler conditions prevail for the second half of the week. For
tonight through tomorrow an upper level trough will continue to dig
into the Great Lakes and Ohio Valley region. This trough will then
start to shift off to the east Tuesday night. A vortmax is moving
across the region now and another will swing through tomorrow
afternoon. At the surface low pressure currently across northern
IN/OH will drag a weak cold front through tonight.
Scattered to numerous showers and thunderstorms will continue across
the forecast area this afternoon and early evening. With PWAT values
hovering near 2" these storms will be very heavy rain producers.
Training of storms will potentially cause ponding of water or
localized flooding. In addition, a few strong wind gusts could be
realized from the strongest storms.
Storms will decrease tonight near sunset and much of the area should
go dry overnight as the front moves through. A few showers could
linger in the east, however. For tomorrow, scattered showers and
storms will again develop as the reinforcing vortmax swings through.
Moisture will not be as high tomorrow, so rainfall intensity should
not be as high as today.
Highs tomorrow look to be a bit cooler than today in the upper 70s
to lower 80s. Lows tonight will be in the mid to upper 60s. As drier
air filters in tomorrow night, lows will drop much lower, bottoming
out in the upper 50s to lower 60s.
.LONG TERM (Wednesday through Monday)...
Issued at 250 PM EDT Mon Aug 11 2014
We`ll begin the long term period with a dry, relatively cool period
as an upper level trough sits over the region with high pressure at
the surface. Expect partly to mostly sunny skies Wed-Sat with high
temps in the upper 70s to mid 80s. Wed looks to be the coolest day
in the long term period with highs in the upper 70s to around 80
across the area. We will start to see some weak ridging work in
from the west by Sat allowing temps to warm into the mid 80s over
most locations. Low temps will be in the upper 50s to lower 60s.
In addition to unseasonably cool temps, humidity levels will be much
lower than the beginning of the week as dewpts drop back into the
50s.
As we head into the beginning of next week, a shortwave upper level
trough will approach the region. Ahead of the trough southerly flow
will usher in moist, unstable air and eventually rain chances.
Models have slowed down on the 12Z runs today delaying rain until at
least Sun night or Mon. Thus, will eliminate POPs for Sun and stick
to low POPs (20-30%) for Sun night-Mon. Temps will climb back into
the upper 80s and possibly approaching 90 by the beginning of next
week.
&&
.AVIATION (00Z TAF Update)...
Issued at 733 PM EDT Mon Aug 11 2014
Look for the SHRA and TSRA to clear out tonight as they continue
their eastward trek and with the loss of daytime heating, will also
assist in diminishing them. Overnight, much drier air will move in
aloft from the NW and behind the fropa, pushing some of the
cloudiness out. However, lingering low-level moisture will allow for
a stratus deck/fog to build in across the region later tonight.
Given the copious amounts of rain that has fallen in and around the
three terminals within the last few days, reduced visibilities
should come easily. IFR conditions can be anticipated at BWG and LEX
with a bit more uncertainty at SDF (have gone with MVFR for now).
Winds should remain light and out of the W to NW through Tuesday
morning.
For tomorrow, an upper-level disturbance will be pushing through the
Ohio Valley, allowing for afternoon clouds to build back in and
winds to increase a bit. Precip chances exist once again at all
three terminals, but the better chances look to be in or around SDF
and LEX. Any convection that develops will be scattered in nature,
thereby leaving specific mention out of the TAFs for now.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........RJS
Short Term.....EER
Long Term......AMS
Aviation.......lg
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1231 AM CDT SUN AUG 10 2014
.AVIATION...
EVENING CONVECTION HAS DISSIPATED WITH MAINLY HIGH CLOUD DEBRIS
REMAINING. EXPECT THE REMAINDER OF THE NIGHT TO BE DRY WITH VFR
CONDITIONS. THE HIGH CLOUDS MAY KEEP FOG AWAY FROM THE MORE PRONE
SITES LIKE KMCB AND KHUM. AS WAS THE CASE ON SATURDAY
MORNING...SHOWERS COULD DEVELOP AS EARLY AS SUNRISE...WITH MOST
THUNDER HOLDING OFF UNTIL MIDDAY. CONVECTIVE CHANCES FOR THE
AFTERNOON LOOK TO BE RATHER HEALTHY AND WILL CARRY A TEMPO GROUP
FOR 20Z-24Z AT ALL SITES WITH TEMPORARY MVFR CIGS AND IFR VSBYS.
ALSO POTENTIAL FOR 25-30 KNOT WINDS WITH THE STRONGER CELLS. 35
&&
.PREV DISCUSSION... /ISSUED 833 PM CDT SAT AUG 9 2014/
..SOUNDING DISCUSSION...
NO ISSUES WITH THIS EVENING/S BALLOON THAT REACHED A HEIGHT OF 22
MILES ABOVE THE GROUND BEFORE BURSTING WEST OF LAKE MAUREPAS.
THUNDERSTORMS THIS AFTERNOON AND EVENING WERE SLOW MOVERS WITH
0-6KM STORM MOTION OF 300 AT 4 KNOTS. PRECIPITABLE WATER VALUES
REMAIN HIGH AT 2.15 INCHES AND RADAR ESTIMATED RAINFALL SHOW SPOTS
WITH AROUND 2 INCH. THE LOW LEVELS UP TO ABOUT 850MB WERE NOT
OVERLY MOIST...BUT FROM 850-500MB THE PROFILE WAS MOISTER WHICH
IS LIKELY A RESULT OF THE BALLOON PASSING THROUGH CLOUDS
ASSOCIATED WITH THE THUNDERSTORMS IN THE AREA. WITH THE MOISTER
MID-LEVELS...NOTE TEMPERATURES WERE 1 TO 3 DEGREES LOWER FROM 24
HOURS AGO. AS FOR WINDS...THEY WERE GENERALLY VARIABLE WITH SPEEDS
BELOW 15 KNOTS FROM THE SURFACE TO ABOUT 450MB. ABOVE
450MB...WINDS WERE PRIMARILY FROM THE EAST WHICH CAN BE CONFIRMED
BY VIEWING IR IMAGERY THIS EVENING.
ANSORGE
PREV DISCUSSION... /ISSUED 300 PM CDT SAT AUG 9 2014/
DISCUSSION...
LITTLE HAS CHANGED IN THE UPPER LEVEL PATTERN WITH WEAK UPPER LEVEL
RIDGE IN PLACE OVER THE AREA WITH THE HIGH REACHING FROM THE
SOUTHEAST GULF OF MEXICO TO ARIZONA. DAYTIME HEATING CONTINUES TO
EASILY OVERCOME ANY SUBSIDENCE IN PLACE AND ALLOWING FOR SCATTERED
SHOWERS AND THUNDERSTORMS ALTHOUGH INTENSITIES ARE SLIGHTLY WEAKER
IN GENERAL COMPARED TO YSTRDY. STORM MOTION HAS FALLEN OFF A BIT
WITH STORMS EXHIBITING LITTLE MOVEMENT. THE MAIN THREAT WITH THIS
ACTIVITY WILL BE CG LIGHTNING AND LOCALIZED HEAVY RAINFALL. CONVECTION
SHOULD DISSIPATE AROUND SUNSET WITH POSSIBLE A FEW SHOWERS OFFSHORE
OVERNIGHT. THE HRRR DOES INDICATE THAT MORE WIDESPREAD STORMS
CURRENTLY LOCATED NORTH OF THE CWA WILL MOVE INTO THE AREA LATE THIS
AFTERNOON BUT THE SLOW MOVEMENT SOUTHWARD AT THIS TIME SAYS
OTHERWISE. THIS DAILY TREND OF SHOWERS AND STORMS ALONG WITH
LOWER/MID 90 HIGHS WILL CONTINUE THROUGH THE WEEKEND AND EARLY NEXT
WEEK. RAIN CHANCES WILL REMAIN ABOUT THE SAME EACH DAY IN THE CHANCE
CATEGORY.
THE PATTERN WILL BEGIN TO CHANGE MOVING INTO THE MIDDLE OF NEXT
WEEK. AN UPPER LEVEL TROUGH WILL DIVE SOUTH OUT OF CANADA AND HEAD
TOWARDS THE SOUTHEASTERN CONUS WHILE RIDGE RETROGRADES BACK WEST. A
COLD FRONT ASSOCIATED WITH THIS FEATURE WILL MAKE ITS WAY DOWN TO
THE CWA IN AROUND MIDDAY TUESDAY. THE FRONT WILL BE STALLING RIGHT
OVER THE AREA AND LIKELY BE A FOCUS FOR STORM AREAL ENHANCEMENT FOR
A FEW DAYS. DOES NOT APPEAR SVR WX WILL BE AN ISSUE WITH WETBULB HT
14KFT AND ABOVE AS WELL AS VERY WEAK WIND FIELD IN PLACE.
MEFFER
AVIATION...
VFR CONDITIONS ARE GENERALLY EXPECTED TO PREVAIL AT THE TERMINALS
THROUGH THE TAF FORECAST PERIOD. ISOLATED CONVECTION THAT MAY IMPACT
THE TAF SITES...PRIMARILY DURING THIS AFTERNOON AFTERNOON AND EARLY
EVENING HOURS. A PERIOD OF LIGHT FOG COULD RESULT IN A PERIOD OF
RESTRICTED VISIBILITIES IN THE MVFR CATEGORY PRIOR TO AND AROUND
SUNRISE SUNDAY MORNING FROM KHUM AND KMCB. 18
MARINE...
A RIDGE OF HIGH PRESSURE WILL PREVAIL ACROSS THE NORTH GULF OF
MEXICO INTO NEXT WEEK. A COLD FRONT WILL APPROACH AND LIKELY STALL
NORTH OF THE CENTRAL GULF COAST BY THE MIDDLE OF THE UPCOMING WEEK.
WINDS WILL GENERALLY BE FROM THE SOUTH TO THE WEST AT 10 KNOTS OR
LESS WITH SEAS 2 FEET OR LESS. 18
DECISION SUPPORT...
DSS CODE...GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 74 92 73 92 / 20 50 40 50
BTR 74 93 74 92 / 20 40 30 50
ASD 75 92 75 92 / 20 40 30 50
MSY 78 91 78 92 / 20 40 30 50
GPT 78 92 78 93 / 20 40 30 50
PQL 73 91 74 91 / 30 40 30 50
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
248 PM EDT SUN AUG 10 2014
.SYNOPSIS...
HIGH PRESSURE REMAINS ALONG THE MID-ATLANTIC COAST THROUGH THE
WEEKEND AS A STATIONARY FRONT LINGERS OVER THE SOUTHEAST STATES. A
SERIES OF LOW PRESSURE SYSTEMS TRACK ALONG THE BOUNDARY THROUGH
MONDAY. A COLD FRONT APPROACHES FROM THE WEST MONDAY...CROSSING THE
REGION TUESDAY INTO WEDNESDAY. HIGH PRESSURE RETURNS LATE IN THE
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST WX ANALYSIS CONTINUES TO FEATURE 1022+MB SFC HIGH PRESSURE
OVER EASTERN CANADA AND THE NORTHEAST CONUS RIDGING SOUTH OVER THE
LOCAL AREA. THIS FEATURE CONTINUES TO KEEP THE VAST MAJORITY OF LIGHT
RAIN SOUTH OF THE AREA. BASED ON LATEST REGIONAL RADAR MOSAIC, PW
VALUE WHICH ARE LARGELY AOB 1.5" (WITH THE EXCEPTION OF FAR SW
ZONES) AND STRONG MID LEVEL CAP (SUBSIDENCE ALOFT)...HAVE REMOVED
POPS FOR MOST OF PIEDMONT COUNTIES THIS AFTN AND RAISED TEMPS
SLIGHTLY OVER THE COASTAL PLAIN. DID HOLD ON TO SOME SLIGHT CHC
(20-30% POP) THIS AFTERNOON OVER SAME SPOTS IN THE SW CWA WHERE
ENOUGH LOW/MID LEVEL MOISTURE COULD BRING SOME LIGHT SHOWERS. MOST
LOCATIONS WILL STAY DRY THIS AFTN, BUT UP TO A TENTH OF AN INCH OF
QPF POSSIBLE WHERE A SHRA POPS UP. HRRR AND OTHER HIGH RES
GUIDANCE IS STILL PICKING UP ON A CONVERGENCE BOUNDARY ALONG THE
CHESAPEAKE BAY THIS AFTERNOON...PLACING LIGHT MODEL QPF FROM THE
PENINSULA NWD TO THE NRN NECK. HOWEVER...LACK OF MOISTURE/DRY LOW
LEVELS WOULD SEEM TO INDICATE THAT THIS IS OVERDONE. CANNOT RULE
OUT A FEW SPRINKLES...BUT AREAL COVERAGE OF ANY QUICK SHOWERS
WOULD BE VERY LOW AND MEASURABLE PRECIP IS NOT ANTICIPATED.
OVERALL. EXPECT PARTLY TO MOSTLY SUNNY SKIES OVER CENTRAL VA NEWD
WITH MOSTLY CLOUDY SKIES PREVAILING OVER THE SW AS CU BEGINS TO
FILL IN EARLY THIS AFTN. HIGHS GENERALLY IN THE LOW TO MID 80S
OVER MUCH OF CENTRAL AND EASTERN VA OVER TO THE EASTERN SHORE,
WITH UPPER 70S TO AROUND 80 IN THE SW.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
UPPER PATTERN AMPLIFIES THROUGH THE SHORT TERM AS A SHORTWAVE TROUGH
DIGS SEWD OVER THE MIDWEST. AN ASSOCIATED COLD FRONT CROSSES THE
MIDWEST...PUSHING INTO THE OH VALLEY TUES. RIDGING BUILDS OVER THE
NERN CONUS AND MID ATLANTIC. MEANWHILE...SFC HIGH PRESSURE REMAINS
JUST OFFSHORE...RIDGING SWWD INTO THE SE STATES. STATIONARY BOUNDARY
REMAINS OVER THE DEEP SOUTH AS A WAVE OF LOW PRESSURE DEVELOPS OVER
SC. SFC LOW WEST OF THE REGION BEGINS TO LIFT NEWD MON AS A LEAD
SHORTWAVE ROTATES THRU THE GREAT LAKES REGION. H85 HIGH ALSO PUSHES
OFFSHORE AS MOISTURE TRANSPORT INCREASES IN SELY FLOW FROM THE GULF
STREAM. EXPECT TWO AREAS OF PRECIP MON...THE FIRST LIFTING OVER THE
CENTRAL APPALACHIANS AND THE SECOND OVER THE CAROLINAS. WHILE MOISTURE
INCREASES OVER THE LOCAL AREA...UPPER/SFC HIGH PRESSURE AND A LACK
OF APPRECIABLE FORCING AND INSTABILITY WILL LIKELY WIN OUT OVER
CENTRAL VA NEWD TO THE ERN SHORE. WILL MAINTAIN CHANCE POPS ON THE WRN
AND SRN PERIPHERIES OF THE FORECAST AREA...CLOSEST TO THE BEST
MOISTURE/LIFT. SHORTWAVE DIGS INTO THE OH VALLEY MON NIGHT-TUES AS
THE COLD FRONT REACHES THE CNTRL APPALACHIANS EARLY TUES. AMPLIFYING
FLOW WILL LIFT THE STATIONARY BOUNDARY NWD AS THE SFC WAVE LIFTS
INTO THE LOWER MID-ATLANTIC REGION. THE SFC HIGH WILL PUSH FARTHER
OFFSHORE. THE WARM SEASON WEDGE WILL BEGIN TO SCOUR OUT AS THE FRONT
AND SHORTWAVE APPROACH. SHORTWAVE AND INCREASING WINDS ALOFT WILL
PROVIDE FORCING FOR ASCENT OVER AN INCREASINGLY MOIST AIRMASS IN
ADVANCE OF THE FRONT. THE RESULT WILL BE SCT SHOWERS BEGINNING MON
NIGHT OVER THE PIEDMONT INTO NRN VA...SPREADING EWD ACROSS THE
ENTIRE AREA TUES. THETA-E ADVECTION AND WARM TEMPS/DEWPOINTS WILL
PRODUCE A MARGINALLY UNSTABLE AIRMASS (MLCAPE VALUES AOB 1K J/KG)
FOR EMBEDDED AFTERNOON THUNDERSTORMS. SHEAR REMAINS
UNIMPRESSIVE...SO ORGANIZED CONVECTION IS NOT ANTICIPATED. SPC HAS
THE REGION IN GENERAL THUNDER. COLD FRONT MOVES INTO THE REGION LATE
TUES-TUES NIGHT.
TEMPS WILL REMAIN BELOW NORMAL THRU THE SHORT TERM...RUNNING 1-2 STD
DEV BELOW NORMAL. HIGHS MON WILL RANGE FROM THE MID 70S SE (STILL IN
THE WEDGE) TO LOW 80S NE. HIGHS TUES GENERALLY IN THE MID 80S. LOWS
IN THE UPPER 60S TO LOW 70S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COLD FRONT CROSSES THE AREAS TUESDAY NIGHT/WEDNESDAY MORNING...
FOLLOWED BY THE RETURN OF HIGH PRESSURE FOR WEDNESDAY AFTERNOON INTO
NEXT WEEKEND. WILL CARRY SOLID CHC POPS (30-50%) EVERYWHERE TUESDAY
NIGHT...TAPERING TO 20-30% POPS EAST OF I-95 WEDNESDAY MORNING. DRY
ALL AREAS BY WEDNESDAY AFTERNOON WITH THE FRONT OFFSHORE. CANADIAN
HIGH PRESSURE THEN SLOWLY BUILDS EASTWARD INTO THE NORTHEAST THROUGH
NEXT WEEKEND. DEW POINTS WILL FALL OFF BY THURSDAY WITH COMFORTABLE
HUMIDITY LEVELS EXPECTED FOR LATE WEEK. HIGHS THRU THE PERIOD 80-85.
LOWS REMAINING GENERALLY IN THE 60S...EXCEPT UPPER 50S IN THE
PIEDMONT WED AND THURS NIGHT.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
4-5K FT CU FILED DEVELOPING ACROSS THE AREA THIS AFTN. MAINLY
EASTERLY FLOW WILL CONTINUE AS HIGH PRESSURE NOSES SOUTH AND LOW
PRESSURE DEVELOPS ALONG A STALLED BOUNDARY OVER THE SE US. PATCHY
FOG WILL AGAIN BE POSSIBLE OVERNIGHT AS THE ATMOSPHERE REMAINS MOIST
AND WINDS RELAX OVERNIGHT. VFR CONDITIONS THEN EXPECTED THROUGH
18Z MON.
OUTLOOK...PATTERN TURNS A BIT MORE UNSETTLED MON/TUE AS FLOW TURNS
TO THE SE AND BRINGS DEEPER MOISTURE TO THE AREA...FOLLOWED BY
SCATTERED TO NUMEROUS SHOWERS MON NIGHT/TUE. A COLD FRONT PUSHES
THROUGH TUE NIGHT/WED WITH VFR/DRY WEATHER FOLLOWING.
&&
.MARINE...
STILL A RELATIVELY WEAK PRESSURE GRADIENT ACRS THE REGION AS SFC
HIGH PRESSURE SLOWLY BECOMES CENTERED OFFSHORE WITH LOW TRACKING NE
THROUGH THE OHIO VALLEY. WINDS WILL REMAIN FAIRLY LIGHT...GENLY 5-10
KT OVER THE BAY/RIVERS TO AROUND 10 KT OFFSHORE. AS A SECONDARY AREA
OF LOW PRESSURE STRENGTHENS A BIT OFF THE SE COAST ON MON...ALLOWING
ONSHORE FLOW TO INCREASE TO AROUND 15-20 KT LATE MON/TUE. WITH THE
ONSHORE FLOW REMAINING LOCKED IN PLACE...THE RESULT WILL BE FOR
BUILDING SEAS. HAVE 2-3 FT SEAS SLOWLY BUILDING TO 3-4 FT MON...THEN
INCREASING TO 4-6 FT MON NIGHT/TUE. 1-2 FT WAVES IN THE BAY WILL
BUILD TO 2-3 FT LATE MON-TUE (POSSIBLY TO 3-4 FT AT THE MOUTH OF THE
BAY). SCA HEADLINES MAY BE NEEDED FOR ALL ZONES LATE MON INTO TUE.
THE PATTERN IS EXPECTED TO BREAK DOWN LATE TUE AS A COLD FRONT
APPROACHES FROM THE WEST AND CROSSES THE AREA ON WED. SEAS FORECAST
TO BEGIN SUBSIDING TUE NIGHT/WED.
&&
.TIDES/COASTAL FLOODING...
PERSISTENT ONSHORE FLOW THIS WEEKEND INTO EARLY NEXT WEEK WILL
SLOWLY PUSH TIDAL ANOMALIES FROM ABOUT 0.5 FT TODAY TO UPWARDS OF
1 FOOT MON/TUE. COMBINATION OF HIGH ASTRONOMICAL TIDES DUE TO A
FULL MOON AND HIGH TIDAL ANOMALIES MAY RESULT IN MINOR COASTAL
FLOODING MON/TUE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...MODERATE RIP CURRENT RISK FROM 8 PM EDT THIS EVENING THROUGH
MONDAY EVENING FOR MDZ025.
NC...NONE.
VA...MODERATE RIP CURRENT RISK FROM 8 PM EDT THIS EVENING THROUGH
MONDAY EVENING FOR VAZ099-100.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM/SAM
NEAR TERM...MAM/SAM
SHORT TERM...SAM
LONG TERM...JDM
AVIATION...LKB/DAP
MARINE...LKB
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1141 AM EDT SUN AUG 10 2014
.SYNOPSIS...
HIGH PRESSURE REMAINS ALONG THE MID-ATLANTIC COAST THROUGH THE
WEEKEND AS A STATIONARY FRONT LINGERS OVER THE SOUTHEAST STATES. A
SERIES OF LOW PRESSURE SYSTEMS TRACK ALONG THE BOUNDARY THROUGH
MONDAY. A COLD FRONT APPROACHES FROM THE WEST MONDAY...CROSSING THE
REGION TUESDAY INTO WEDNESDAY. HIGH PRESSURE RETURNS LATE IN THE
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST WX ANALYSIS CONTINUES TO FEATURE 1022+MB SFC HIGH PRESSURE
OVER EASTERN CANADA AND THE NORTHEAST CONUS RIDGING SOUTH OVER THE
LOCAL AREA. THIS FEATURE CONTINUES TO KEEP THE VAST MAJORITY OF LIGHT
RAIN SOUTH OF THE AREA. BASED ON LATEST REGIONAL RADAR MOSAIC, PW
VALUE WHICH ARE LARGELY AOB 1.5" (WITH THE EXCEPTION OF FAR SW
ZONES) AND STRONG MID LEVEL CAP (SUBSIDENCE ALOFT)...HAVE REMOVED
POPS FOR MOST OF PIEDMONT COUNTIES THIS AFTN AND RAISED TEMPS
SLIGHTLY OVER THE COASTAL PLAIN. DID HOLD ON TO SOME SLIGHT CHC
(20-30% POP) THIS AFTERNOON OVER SAME SPOTS IN THE SW CWA WHERE
ENOUGH LOW/MID LEVEL MOISTURE COULD BRING SOME LIGHT SHOWERS. MOST
LOCATIONS WILL STAY DRY THIS AFTN, BUT UP TO A TENTH OF AN INCH OF
QPF POSSIBLE WHERE A SHRA POPS UP. HRRR AND OTHER HIGH RES
GUIDANCE IS STILL PICKING UP ON A CONVERGENCE BOUNDARY ALONG THE
CHESAPEAKE BAY THIS AFTERNOON...PLACING LIGHT MODEL QPF FROM THE
PENINSULA NWD TO THE NRN NECK. HOWEVER...LACK OF MOISTURE/DRY LOW
LEVELS WOULD SEEM TO INDICATE THAT THIS IS OVERDONE. CANNOT RULE
OUT A FEW SPRINKLES...BUT AREAL COVERAGE OF ANY QUICK SHOWERS
WOULD BE VERY LOW AND MEASURABLE PRECIP IS NOT ANTICIPATED.
OVERALL. EXPECT PARTLY TO MOSTLY SUNNY SKIES OVER CENTRAL VA NEWD
WITH MOSTLY CLOUDY SKIES PREVAILING OVER THE SW AS CU BEGINS TO
FILL IN EARLY THIS AFTN. HIGHS GENERALLY IN THE LOW TO MID 80S
OVER MUCH OF CENTRAL AND EASTERN VA OVER TO THE EASTERN SHORE,
WITH UPPER 70S TO AROUND 80 IN THE SW.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
UPPER PATTERN AMPLIFIES THROUGH THE SHORT TERM AS A SHORTWAVE TROUGH
DIGS SEWD OVER THE MIDWEST. AN ASSOCIATED COLD FRONT CROSSES THE
MIDWEST...PUSHING INTO THE OH VALLEY TUES. RIDGING BUILDS OVER THE
NERN CONUS AND MID ATLANTIC. MEANWHILE...SFC HIGH PRESSURE REMAINS
JUST OFFSHORE...RIDGING SWWD INTO THE SE STATES. STATIONARY BOUNDARY
REMAINS OVER THE DEEP SOUTH AS A WAVE OF LOW PRESSURE DEVELOPS OVER
SC. SFC LOW WEST OF THE REGION BEGINS TO LIFT NEWD MON AS A LEAD
SHORTWAVE ROTATES THRU THE GREAT LAKES REGION. H85 HIGH ALSO PUSHES
OFFSHORE AS MOISTURE TRANSPORT INCREASES IN SELY FLOW FROM THE GULF
STREAM. EXPECT TWO AREAS OF PRECIP MON...THE FIRST LIFTING OVER THE
CENTRAL APPALACHIANS AND THE SECOND OVER THE CAROLINAS. WHILE MOISTURE
INCREASES OVER THE LOCAL AREA...UPPER/SFC HIGH PRESSURE AND A LACK
OF APPRECIABLE FORCING AND INSTABILITY WILL LIKELY WIN OUT OVER
CENTRAL VA NEWD TO THE ERN SHORE. WILL MAINTAIN CHANCE POPS ON THE WRN
AND SRN PERIPHERIES OF THE FORECAST AREA...CLOSEST TO THE BEST
MOISTURE/LIFT. SHORTWAVE DIGS INTO THE OH VALLEY MON NIGHT-TUES AS
THE COLD FRONT REACHES THE CNTRL APPALACHIANS EARLY TUES. AMPLIFYING
FLOW WILL LIFT THE STATIONARY BOUNDARY NWD AS THE SFC WAVE LIFTS
INTO THE LOWER MID-ATLANTIC REGION. THE SFC HIGH WILL PUSH FARTHER
OFFSHORE. THE WARM SEASON WEDGE WILL BEGIN TO SCOUR OUT AS THE FRONT
AND SHORTWAVE APPROACH. SHORTWAVE AND INCREASING WINDS ALOFT WILL
PROVIDE FORCING FOR ASCENT OVER AN INCREASINGLY MOIST AIRMASS IN
ADVANCE OF THE FRONT. THE RESULT WILL BE SCT SHOWERS BEGINNING MON
NIGHT OVER THE PIEDMONT INTO NRN VA...SPREADING EWD ACROSS THE
ENTIRE AREA TUES. THETA-E ADVECTION AND WARM TEMPS/DEWPOINTS WILL
PRODUCE A MARGINALLY UNSTABLE AIRMASS (MLCAPE VALUES AOB 1K J/KG)
FOR EMBEDDED AFTERNOON THUNDERSTORMS. SHEAR REMAINS
UNIMPRESSIVE...SO ORGANIZED CONVECTION IS NOT ANTICIPATED. SPC HAS
THE REGION IN GENERAL THUNDER. COLD FRONT MOVES INTO THE REGION LATE
TUES-TUES NIGHT.
TEMPS WILL REMAIN BELOW NORMAL THRU THE SHORT TERM...RUNNING 1-2 STD
DEV BELOW NORMAL. HIGHS MON WILL RANGE FROM THE MID 70S SE (STILL IN
THE WEDGE) TO LOW 80S NE. HIGHS TUES GENERALLY IN THE MID 80S. LOWS
IN THE UPPER 60S TO LOW 70S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COLD FRONT CROSSES THE AREAS TUESDAY NIGHT/WEDNESDAY MORNING...
FOLLOWED BY THE RETURN OF HIGH PRESSURE FOR WEDNESDAY AFTERNOON INTO
NEXT WEEKEND. WILL CARRY SOLID CHC POPS (30-50%) EVERYWHERE TUESDAY
NIGHT...TAPERING TO 20-30% POPS EAST OF I-95 WEDNESDAY MORNING. DRY
ALL AREAS BY WEDNESDAY AFTERNOON WITH THE FRONT OFFSHORE. CANADIAN
HIGH PRESSURE THEN SLOWLY BUILDS EASTWARD INTO THE NORTHEAST THROUGH
NEXT WEEKEND. DEW POINTS WILL FALL OFF BY THURSDAY WITH COMFORTABLE
HUMIDITY LEVELS EXPECTED FOR LATE WEEK. HIGHS THRU THE PERIOD 80-85.
LOWS REMAINING GENERALLY IN THE 60S...EXCEPT UPPER 50S IN THE
PIEDMONT WED AND THURS NIGHT.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
AS OF 12Z...PATCHY FOG WILL SCATTER OUT AND LEAVE MOSTLY
CLEAR/PARTLY CLOUDY CONDITIONS TODAY WITH E/SE FLOW OF 10 KT OR
LESS. ONLY A MINIMAL CHANCE FOR RAIN AT KECG...DRY ELSEWHERE TODAY
AS BULK OF PRECIP STAYS FARTHER SOUTH OVER NC.
OUTLOOK...PATTERN TURNS A BIT MORE UNSETTLED MON/TUE AS FLOW TURNS
TO THE SE AND BRINGS DEEPER MOISTURE TO THE AREA WITH SOME LOW
CIGS AND/OR VSBYS POSSIBLE EARLY MON AM...FOLLOWED BY SCATTERED TO
NUMEROUS SHOWERS MON NIGHT/TUE. A COLD FRONT PUSHES THROUGH TUE NIGHT/WED
WITH VFR/DRY WEATHER FOLLOWING.
&&
.MARINE...
STILL A RELATIVELY WEAK PRESSURE GRADIENT ACRS THE REGION AS SFC
HIGH PRESSURE SLOWLY BECOMES CENTERED OFFSHORE WITH LOW TRACKING NE
THROUGH THE OHIO VALLEY. WINDS WILL REMAIN FAIRLY LIGHT...GENLY 5-10
KT OVER THE BAY/RIVERS TO AROUND 10 KT OFFSHORE. AS A SECONDARY AREA
OF LOW PRESSURE STRENGTHENS A BIT OFF THE SE COAST ON MON...ALLOWING
ONSHORE FLOW TO INCREASE TO AROUND 15-20 KT LATE MON/TUE. WITH THE
ONSHORE FLOW REMAINING LOCKED IN PLACE...THE RESULT WILL BE FOR
BUILDING SEAS. HAVE 2-3 FT SEAS SLOWLY BUILDING TO 3-4 FT MON...THEN
INCREASING TO 4-6 FT MON NIGHT/TUE. 1-2 FT WAVES IN THE BAY WILL
BUILD TO 2-3 FT LATE MON-TUE (POSSIBLY TO 3-4 FT AT THE MOUTH OF THE
BAY). SCA HEADLINES MAY BE NEEDED FOR ALL ZONES LATE MON INTO TUE.
THE PATTERN IS EXPECTED TO BREAK DOWN LATE TUE AS A COLD FRONT
APPROACHES FROM THE WEST AND CROSSES THE AREA ON WED. SEAS FORECAST
TO BEGIN SUBSIDING TUE NIGHT/WED.
&&
.TIDES/COASTAL FLOODING...
PERSISTENT ONSHORE FLOW THIS WEEKEND INTO EARLY NEXT WEEK WILL
SLOWLY PUSH TIDAL ANOMALIES FROM ABOUT 0.5 FT TODAY TO UPWARDS OF
1 FOOT MON/TUE. COMBINATION OF HIGH ASTRONOMICAL TIDES DUE TO A
FULL MOON AND HIGH TIDAL ANOMALIES MAY RESULT IN MINOR COASTAL
FLOODING MON/TUE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR
NCZ102.
VA...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR
VAZ098.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM/SAM
NEAR TERM...MAM/SAM
SHORT TERM...SAM
LONG TERM...JDM
AVIATION...LKB
MARINE...LKB
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
653 PM EDT SUN AUG 10 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 404 PM EDT SUN AUG 10 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL FROM THE
CNTRL/SRN ROCKIES TO THE PAC NW AND A TROUGH FROM WEST OF HUDSON BAY
TOWARD THE UPPER MS VALLEY. A WEAK SHRTWV OVER CNTRL MN AHEAD OF A
FRONT FROM NW ONTARIO INTO WRN MN SUPPORTED SCT/NMRS SHRA/TSRA FROM
N CNTRL MN INTO NW IA. OTHERWISE...JUST DIURNAL CU PREVAILED ACROSS
UPPER MI AS WEAK SRLY FLOW GRADUALLY INCREASED.
TONIGHT...EXPECT THE UPSTREAM MID LEVEL TROUGH TO DIG SOUTHEASTWARD
AS A 100 KNOT 250 MB JET STREAK DIVES TOWARD THE NRN PLAINS. AS
MOISTURE INCREASES AHEAD OF THE FRONT...EXPECT THE SHRA AND A FEW
TSRA TO ADVANCE STEADILY TO THE EAST WITH CHANCE POPS ACROSS THE WRN
THIRD INCREASING AFT 06Z.
MON...AS THE TROUGH CONTINUES TO DEEPEN...MID LEVEL QVECTOR CONV AND
FGEN COMBINED WITH INCREASING MOISTURE(PWAT TO 1.5 INCHES OR 150 PCT
OR NORMAL) WILL SUPPORT LIKELY POPS MOVING ACROSS THE CWA. MODELS
MUCAPE VALUES OF ONLY 100-400 J/KG WITH SKINNY CAPE PROFILES
SUGGESTS MAINLY ISOLD TSRA WILL BE POSSIBLE. AS NORTH WINDS INCREASE
BEHIND THE FRONT...TEMPS SHOULD REMAIN STEADY OR DROP OFF DURING THE
AFTERNOON...ESPECIALLY NEAR LAKE SUPERIOR.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 257 PM EDT SUN AUG 10 2014
AN UPPER LEVEL TROUGH WILL BE MOVING THROUGH THE UPPER GREAT LAKES
REGION AT THE START OF THE LONG TERM PERIOD AND LEAD TO THE
DEVELOPMENT OF A WEAK LOW OVER EASTERN LOWER MICHIGAN AND LAKE
HURON ON MONDAY NIGHT. THE SLOW SHIFT OF THE UPPER TROUGH AND
SURFACE LOW EAST-NORTHEAST ON MONDAY NIGHT INTO TUESDAY WILL BRING
A GRADUAL DECREASE IN PRECIPITATION/CLOUDS FROM WEST TO EAST
MONDAY NIGHT INTO TUESDAY. WITH DEEP MOISTURE WRAPPING AROUND THE
SURFACE LOW OVER EASTERN UPPER MICHIGAN...EXPECT THE BEST
OPPORTUNITY FOR MODERATE RAINFALL (LIKELY POPS) THERE ON MONDAY
NIGHT. THE CLOUDS SHOULD REMAIN THROUGH THE DAY OVER THE EAST
(MAINLY EAST OF MUNISING/MANISTIQUE) BEFORE DIMINISHING DURING THE
EVENING HOURS AS THE DEEPER MOISTURE DEPARTS. WILL CONTINUE TO HOLD
ONTO CHANCE POPS OVER THOSE EAST AREAS IN THE MORNING AND THEN
SLOWLY END THEM THROUGH THE AFTERNOON AND EVENING HOURS.
ELSEWHERE...PRECIPITATION CHANCES WILL BE DEPENDANT ON HOW QUICKLY
THE LOW LEVEL MOISTURE DEPARTS FROM WEST TO EAST. THINK THE FAR
WESTERN CWA MAY START SEEING SOME BREAKS IN THE CLOUDS DURING THE
EVENING AND EARLY OVERNIGHT HOURS...AS DRIER AIR WRAPS INTO THE
AREA. CLOUDS WILL THEN QUICKLY DIMINISH THROUGH TUESDAY MORNING.
THE CENTRAL CWA WILL LIKELY STAY SOCKED IN WITH LOW CLOUDS THROUGH
TUESDAY MONRING HOURS...ESPECIALLY OVER THE NORTH CENTRAL...WHERE
NORTHERLY WINDS WILL AID UPSLOPE CLOUDS AND DRIZZLE/-RA BEFORE
DIMINISHING IN THE AFTERNOON. IN ADDITION TO THE LOW CLOUDS AND RAIN
SHOWERS...NORTHERLY WINDS WILL BE ON THE INCREASE THROUGH THE NIGHT
AND REMAIN GUSTY THROUGH TUESDAY...ESPECIALLY OVER THE CENTRAL AND
EASTERN CWA...WHERE WINDS WILL GUST TO THE 15-25KT RANGE. THESE
GUSTY WINDS...CLOUDY SKIES...AND TEMPERATURES IN THE 50S WILL
LEAD TO A VERY FALL LIKE START TO TUESDAY OVER PORTIONS OF THE U.P.
FINALLY FOR TUESDAY...THERE IS A POTENTIAL FOR A HIGH SWIM RISK FOR
MARQUETTE AND ESPECIALLY ALGER COUNTY AND WILL ADD A MENTION TO THE
HWO.
FOR THE REST OF THE WORK WEEK...THE UPPER LOW BRIEFLY CLOSES OFF
OVER SOUTHERN QUEBEC AND THE EASTERN GREAT LAKES ON
WEDNESDAY/THURSDAY BEFORE LIFTING NORTHEAST ON FRIDAY. THIS WILL
LEAD TO NORTHWESTERLY FLOW ALOFT AND ALLOW A SURFACE HIGH PRESSURE
RIDGE TO SLOWLY SHIFT EAST ACROSS THE CWA. A SECONDARY SHORTWAVE
DROPPING SOUTHEAST ACROSS THE CWA COULD PRODUCE SOME CLOUDS AND A
FEW SPRINKLES OVER PORTIONS OF WESTERN/CENTRAL UPPER MICHIGAN ON
TUESDAY NIGHT INTO WEDNESDAY MORNING...OTHERWISE EXPECT THE WAVES
TO STAY TO THE EAST OF THE CWA. THE INCREASING INFLUENCE OF THE
SURFACE HIGH WILL BRING GRADUALLY DIMINISHING WINDS AND MOSTLY
CLEAR SKIES FOR WEDNESDAY AFTERNOON THROUGH FRIDAY NIGHT. THE
NORTHERLY FLOW ALOFT WILL KEEP 850MB TEMPS A FEW DEGREES BELOW
NORMAL AND EXPECT THE DAYTIME HIGHS TO BE SIMILAR (ESPECIALLY NEAR
LAKE SUPERIOR). HIGHS OVER INTERIOR LOCATIONS WILL BE IN THE
70S...WHILE LOCATIONS NEAR LAKE SUPERIOR WILL BE IN THE UPPER 60S.
HEADING INTO NEXT WEEKEND...THE UPPER TROUGH THAT COMES ONSHORE OVER
THE PACIFIC NORTHWEST ON TUESDAY WILL BREAK DOWN THE UPPER RIDGE
OVER THE ROCKIES AND SHIFT EAST TOWARDS THE UPPER GREAT LAKES
REGION. LATEST TREND IN THE MODELS IS FOR A LITTLE LATER ARRIVAL
THAN SHOWN YESTERDAY...WHICH SHOULD KEEP MUCH OF SATURDAY DRY AS
THE SURFACE HIGH HOLDS ON. THE PRECIPITATION CHANCES WILL BE ON THE
INCREASE SATURDAY NIGHT AND INTO SUNDAY...AS THE SURFACE RIDGE
DEPARTS AND THE UPPER LEVEL DISTURBANCE MOVES TOWARDS THE AREA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 653 PM EDT SUN AUG 10 2014
VFR CONDITIONS WITH LIGHT WINDS ARE EXPECTED MOST OF THE NIGHT. A
FRONTAL SYSTEM WILL MOVE INTO THE AREA BRINGING AREAS OF RAIN AND
POSSIBLY A THUNDERSTORM THAT MAY LOWER CONDITIONS INTO THE MVFR
RANGE BY MON MORNING AT CMX AND IWD. LOWER CLOUDS BEHIND THE FRONT
SHOULD DROP CONDITIONS INTO THE IFR RANGE ARE EXPECTED AT CMX/IWD
MON MORNING AND IN THE AFTERNOON AT SAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 404 PM EDT SUN AUG 10 2014
A COLD FRONT WILL MOVE ACROSS THE LAKE TONIGHT INTO MONDAY. BEHIND
THE COLD FRONT...NORTH WINDS WILL INCREASE MON AND GUST TO MORE THAN
20 KT MON NIGHT INTO TUE...PRODUCING WAVES UP TO 7 FT. HIGH PRESSURE
BUILDING INTO THE AREA BY WED NIGHT WILL ALLOW WINDS TO ONCE AGAIN
SUBSIDE TO BELOW 15 KT BY LATE WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
404 PM EDT SUN AUG 10 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 404 PM EDT SUN AUG 10 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL FROM THE
CNTRL/SRN ROCKIES TO THE PAC NW AND A TROUGH FROM WEST OF HUDSON BAY
TOWARD THE UPPER MS VALLEY. A WEAK SHRTWV OVER CNTRL MN AHEAD OF A
FRONT FROM NW ONTARIO INTO WRN MN SUPPORTED SCT/NMRS SHRA/TSRA FROM
N CNTRL MN INTO NW IA. OTHERWISE...JUST DIURNAL CU PREVAILED ACROSS
UPPER MI AS WEAK SRLY FLOW GRADUALLY INCREASED.
TONIGHT...EXPECT THE UPSTREAM MID LEVEL TROUGH TO DIG SOUTHEASTWARD
AS A 100 KNOT 250 MB JET STREAK DIVES TOWARD THE NRN PLAINS. AS
MOISTURE INCREASES AHEAD OF THE FRONT...EXPECT THE SHRA AND A FEW
TSRA TO ADVANCE STEADILY TO THE EAST WITH CHANCE POPS ACROSS THE WRN
THIRD INCREASING AFT 06Z.
MON...AS THE TROUGH CONTINUES TO DEEPEN...MID LEVEL QVECTOR CONV AND
FGEN COMBINED WITH INCREASING MOISTURE(PWAT TO 1.5 INCHES OR 150 PCT
OR NORMAL) WILL SUPPORT LIKELY POPS MOVING ACROSS THE CWA. MODELS
MUCAPE VALUES OF ONLY 100-400 J/KG WITH SKINNY CAPE PROFILES
SUGGESTS MAINLY ISOLD TSRA WILL BE POSSIBLE. AS NORTH WINDS INCREASE
BEHIND THE FRONT...TEMPS SHOULD REMAIN STEADY OR DROP OFF DURING THE
AFTERNOON...ESPECIALLY NEAR LAKE SUPERIOR.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 257 PM EDT SUN AUG 10 2014
AN UPPER LEVEL TROUGH WILL BE MOVING THROUGH THE UPPER GREAT LAKES
REGION AT THE START OF THE LONG TERM PERIOD AND LEAD TO THE
DEVELOPMENT OF A WEAK LOW OVER EASTERN LOWER MICHIGAN AND LAKE
HURON ON MONDAY NIGHT. THE SLOW SHIFT OF THE UPPER TROUGH AND
SURFACE LOW EAST-NORTHEAST ON MONDAY NIGHT INTO TUESDAY WILL BRING
A GRADUAL DECREASE IN PRECIPITATION/CLOUDS FROM WEST TO EAST
MONDAY NIGHT INTO TUESDAY. WITH DEEP MOISTURE WRAPPING AROUND THE
SURFACE LOW OVER EASTERN UPPER MICHIGAN...EXPECT THE BEST
OPPORTUNITY FOR MODERATE RAINFALL (LIKELY POPS) THERE ON MONDAY
NIGHT. THE CLOUDS SHOULD REMAIN THROUGH THE DAY OVER THE EAST
(MAINLY EAST OF MUNISING/MANISTIQUE) BEFORE DIMINISHING DURING THE
EVENING HOURS AS THE DEEPER MOISTURE DEPARTS. WILL CONTINUE TO HOLD
ONTO CHANCE POPS OVER THOSE EAST AREAS IN THE MORNING AND THEN
SLOWLY END THEM THROUGH THE AFTERNOON AND EVENING HOURS.
ELSEWHERE...PRECIPITATION CHANCES WILL BE DEPENDANT ON HOW QUICKLY
THE LOW LEVEL MOISTURE DEPARTS FROM WEST TO EAST. THINK THE FAR
WESTERN CWA MAY START SEEING SOME BREAKS IN THE CLOUDS DURING THE
EVENING AND EARLY OVERNIGHT HOURS...AS DRIER AIR WRAPS INTO THE
AREA. CLOUDS WILL THEN QUICKLY DIMINISH THROUGH TUESDAY MORNING.
THE CENTRAL CWA WILL LIKELY STAY SOCKED IN WITH LOW CLOUDS THROUGH
TUESDAY MONRING HOURS...ESPECIALLY OVER THE NORTH CENTRAL...WHERE
NORTHERLY WINDS WILL AID UPSLOPE CLOUDS AND DRIZZLE/-RA BEFORE
DIMINISHING IN THE AFTERNOON. IN ADDITION TO THE LOW CLOUDS AND RAIN
SHOWERS...NORTHERLY WINDS WILL BE ON THE INCREASE THROUGH THE NIGHT
AND REMAIN GUSTY THROUGH TUESDAY...ESPECIALLY OVER THE CENTRAL AND
EASTERN CWA...WHERE WINDS WILL GUST TO THE 15-25KT RANGE. THESE
GUSTY WINDS...CLOUDY SKIES...AND TEMPERATURES IN THE 50S WILL
LEAD TO A VERY FALL LIKE START TO TUESDAY OVER PORTIONS OF THE U.P.
FINALLY FOR TUESDAY...THERE IS A POTENTIAL FOR A HIGH SWIM RISK FOR
MARQUETTE AND ESPECIALLY ALGER COUNTY AND WILL ADD A MENTION TO THE
HWO.
FOR THE REST OF THE WORK WEEK...THE UPPER LOW BRIEFLY CLOSES OFF
OVER SOUTHERN QUEBEC AND THE EASTERN GREAT LAKES ON
WEDNESDAY/THURSDAY BEFORE LIFTING NORTHEAST ON FRIDAY. THIS WILL
LEAD TO NORTHWESTERLY FLOW ALOFT AND ALLOW A SURFACE HIGH PRESSURE
RIDGE TO SLOWLY SHIFT EAST ACROSS THE CWA. A SECONDARY SHORTWAVE
DROPPING SOUTHEAST ACROSS THE CWA COULD PRODUCE SOME CLOUDS AND A
FEW SPRINKLES OVER PORTIONS OF WESTERN/CENTRAL UPPER MICHIGAN ON
TUESDAY NIGHT INTO WEDNESDAY MORNING...OTHERWISE EXPECT THE WAVES
TO STAY TO THE EAST OF THE CWA. THE INCREASING INFLUENCE OF THE
SURFACE HIGH WILL BRING GRADUALLY DIMINISHING WINDS AND MOSTLY
CLEAR SKIES FOR WEDNESDAY AFTERNOON THROUGH FRIDAY NIGHT. THE
NORTHERLY FLOW ALOFT WILL KEEP 850MB TEMPS A FEW DEGREES BELOW
NORMAL AND EXPECT THE DAYTIME HIGHS TO BE SIMILAR (ESPECIALLY NEAR
LAKE SUPERIOR). HIGHS OVER INTERIOR LOCATIONS WILL BE IN THE
70S...WHILE LOCATIONS NEAR LAKE SUPERIOR WILL BE IN THE UPPER 60S.
HEADING INTO NEXT WEEKEND...THE UPPER TROUGH THAT COMES ONSHORE OVER
THE PACIFIC NORTHWEST ON TUESDAY WILL BREAK DOWN THE UPPER RIDGE
OVER THE ROCKIES AND SHIFT EAST TOWARDS THE UPPER GREAT LAKES
REGION. LATEST TREND IN THE MODELS IS FOR A LITTLE LATER ARRIVAL
THAN SHOWN YESTERDAY...WHICH SHOULD KEEP MUCH OF SATURDAY DRY AS
THE SURFACE HIGH HOLDS ON. THE PRECIPITATION CHANCES WILL BE ON THE
INCREASE SATURDAY NIGHT AND INTO SUNDAY...AS THE SURFACE RIDGE
DEPARTS AND THE UPPER LEVEL DISTURBANCE MOVES TOWARDS THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 157 PM EDT SUN AUG 10 2014
VFR CONDITIONS WITH LIGHT WINDS ARE EXPECTED THROUGH THIS EVENING.
OVERNIGHT...A FRONTAL SYSTEM WILL MOVE INTO THE AREA BRINGING AREAS
OF RAIN AND POSSIBLY A THUNDERSTORM THAT MAY LOWER CONDITIONS INTO
THE MVFR RANGE LATE TONIGHT AT CMX AND IWD. WITH ONLY A LOW
PROBABILITY OF TS...NO MENTION WAS ADDED TO THE TAF AT THIS TIME.
LOWER CLOUDS BEHIND THE FRONT SHOULD DROP CONDITIONS INTO THE IFR
RANGE ARE EXPECTED AT CMX/IWD. AT SAW...RAIN CHANCES AND POTENTIAL
FOR MVFR CIGS WILL ARRIVE TOWARD THE END OF THE TAF PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 404 PM EDT SUN AUG 10 2014
A COLD FRONT WILL MOVE ACROSS THE LAKE TONIGHT INTO MONDAY. BEHIND
THE COLD FRONT...NORTH WINDS WILL INCREASE MON AND GUST TO MORE THAN
20 KT MON NIGHT INTO TUE...PRODUCING WAVES UP TO 7 FT. HIGH PRESSURE
BUILDING INTO THE AREA BY WED NIGHT WILL ALLOW WINDS TO ONCE AGAIN
SUBSIDE TO BELOW 15 KT BY LATE WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
249 PM CDT SUN AUG 10 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 244 PM CDT SUN AUG 10 2014
AN UNSETTLED WEATHER PATTERN EXISTS ACROSS CENTRAL NOAM...WITH A
STRONG WAVE ENTERING WRN HUDSON BAY. THE TROUGH ASSOCIATED WITH THIS
UPPER LOW EXTENDS SOUTH INTO NRN MO. WITHIN THIS TROUGH THERE AREA A
COUPLE OF UPPER LOWS...A WEAKENING ONE OVER CENTRAL MN THAT BROUGHT
THE HEAVY RAINS TO WRN MN LAST NIGHT WITH AN MCV DOWN OVER CENTRAL
IA. AT THE SFC...OBS SHOW A WEAK LOW OVER CENTRAL MN UNDER THE
WEAKENING UPPER LOW. AT 2 PM...THE COLD FRONT EXTENDED SOUTH FROM
THE LOW THROUGH LITCHFIELD...WINDOM...AND INTO NW IA. THE MOST
WIDESPREAD PRECIPITATION THROUGH TONIGHT IS EXPECTED NORTH OF THE
MPX AREA WITH THE CENTRAL MN UPPER LOW AND WELL SOUTH OF MN/WI WITH
THE MCV. WE HAVE SEEN AN UNCAPPED 500-1000 J/KG OF MLCAPE DEVELOP
ALONG THE FRONT...WHICH HAS PROMOTED THE DEVELOPMENT OF A BROKEN
LINE OF STORMS ACROSS MN. HRRR AND MEMBERS 1 AND 3 OF THE HOPWRF
HAVE HAD A GOOD HANDEL ON THINGS TODAY...SO FOLLOWED THOSE MODELS
FOR TRACKING SHOWERS/STORMS ACROSS THE AREA. THIS RESULTED IN
SLOWING THE EWRD PROGRESSION OF POPS INTO WI...WHICH MAKES SENSE AS
ONCE AGAIN WE HAVE SEEN DEWPS OUT EAST DROP INTO THE MID 50S...DRY
AIR OUT THERE HAS BEEN VERY HESITANT TO LEAVE INDEED. BESIDE SLOWING
THE PROGRESSION OF POPS TO THE EAST...ALSO DECREASED POPS OVER WI
OVERNIGHT...AS SHOWERS REALLY LOOK TO LOOSE THEIR DEFINITION AFTER
SUNSET...WITH BEST FORCING WITH THE UPPER LOWS GOING INTO NRN WI AND
NRN IL OVERNIGHT. ALSO RESTRICTED POPS TO JUST WRN WI FOR MONDAY AND
HELD THEM INTO THE CHANCE CATEGORY AS WELL...AS UPPER WAVE DROPPING
DOWN OUT OF CANADA TONIGHT HEADS FOR CENTRAL WI MONDAY AFTERNOON. BY
THEN...BEST MOISTURE WILL BE MAINLY EAST OF THE MPX AREA...WITH
CURRENT REDUCED POPS POSSIBLY EVEN A BIT OVERDONE FOR MONDAY
AFTERNOON.
BESIDE BABYSITTING THE PRECIP ACROSS ERN AREAS TONIGHT...WILL ALSO
HAVE TO WATCH FOR FOG DEVELOPMENT OUT IN WRN MN. WE SAW A GOOD SWATH
OF 1-4+ INCHES OF RAIN OUT THERE OVERNIGHT AND AS WE GO THROUGH THE
NIGHT TONIGHT...SKIES WILL BEGIN TO CLEAR. HOWEVER...THIS CLEARING
WILL ALSO BE ACCOMPANIED BY DECREASING DEWPOINTS AND FAIRLY
PERSISTENT LIGHT NW WINDS. LEFT FOG OUT OF GRIDS FOR NOW THINKING
THESE NW WINDS WOULD KEEP THE ATMO MIXED ENOUGH TO KEEP FOG FROM
FORMING...BUT THEY WILL BE SUSCEPTIBLE TO FOG FORMATION GIVEN THE
RECENT HEAVY RAIN.
FOR MONDAY...OTHER THAN THE THREAT FOR SOME ISO/SCT STORMS OVER WRN
WI IN THE AFTERNOON...IT WILL BE YET ANOTHER STELLAR SUMMER DAY AS
SKIES CLEAR OUT...TEMPS WARM INTO THE MID/UPPER 70S...DEWPOINTS FALL
INTO THE 50S...ALL TOPPED OFF WITH A FRESH NNW WIND THAT WILL BE
GUSTING TO BETWEEN 20 AND 25 MPH.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 244 PM CDT SUN AUG 10 2014
DRY WEATHER WILL CONTINUE THROUGH MUCH OF THE PERIOD UNTIL WARM
MOIST AIR RETURNS ACROSS THE REGION BY THE END OF THE WEEK. IN THE
MEAN TIME EXPECT LITTLE CHANGE FROM THE WEATHER EXPERIENCED OVER THE
PAST COUPLE OF WEEKS.
FROM A BROAD BRUSHED PERSPECTIVE...IN ORDER TO MAKE A CONFIDENT
FORECAST FOR WIDESPREAD PRECIPITATION ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY DURING THE WARM SEASON YOU NEED EITHER LARGE SCALE
ASCENT IN THE FORM OF UPPER LEVEL DIVERGENCE...OR MORE COMMONLY LOW
LEVEL CONVERGENCE AND MOISTURE TRANSPORT ACROSS A FRONTAL BOUNDARY
FROM THE LOW LEVEL JET. OVER THE PAST FEW WEEKS NEITHER MN NOR WI
HAVE HAD EITHER...AND AS A RESULT THE WEATHER HAS BEEN NOTICEABLY
DRY.
A 36HR LOOP OF NORTH AMERICAN WATER VAPOR IMAGERY...TOGETHER WITH
GFS 500MB HEIGHTS AND WINDS SHOWED THE ACTIVE STORM TRACK SITUATED
TO THE NORTH ACROSS CENTRAL CANADA...WHILE RECURRING AFTERNOON
CONVECTION FIRED ACROSS THE CENTRAL CONUS ON THE LEE SIDE OF THE
ROCKIES OWING TO UPSLOPE FLOW. AS THE NIGHT PROGRESSED...THE
CONVECTION DRIFTED EASTWARD ACROSS THE PLAIN STATES OF NE AND KS.
ALTHOUGH ISOLATED AREAS OF WESTERN MN DID PICK UP HEALTHY RAINFALL
TOTALS OVER THE PAST 24HRS...THE COVERAGE WAS LIMITED TO A
RELATIVELY SMALL AREA...SIMILAR TO THE ISOLATED HEAVY RAIN THAT FELL
IN WESTERN WI THE PREVIOUS WEEK.
IN THE WAKE OF A WASHED OUT FRONTAL PASSAGE...THE REMAINDER OF THE
WORK WEEK WILL BE DRY AS NORTHWEST FLOW AND SURFACE HIGH PRESSURE
PERSIST ACROSS THE REGION. ON THURSDAY ANOTHER MCS WILL TRICKLE DOWN
THE MISSOURI RIVER VALLEY AND COULD CLIP THE SOUTHWESTERN PART OF
THE CWA. BY THE TIME THE WEEKEND ROLLS AROUND...EXTENDED MODELS
CONTINUE TO SHOW A TRANSITION TO A MORE ZONAL UPPER LEVEL PATTERN
WITH LOW LEVEL MOISTURE RETURNING FROM THE SOUTH. THIS WOULD
INCREASE THE POTENTIAL FOR PRECIP ACROSS THE REGION. IF THIS MODEL
SOLUTION PANS OUT HAVE FAIRLY HIGH CONFIDENCE THAT MOST OF THE
REGION WOULD PICK UP MEASURABLE RAINFALL DURING THE SATURDAY/SUNDAY
TIMEFRAME...BUT WILL NOT GO HIGHER THAN GUIDANCE WITH PRECIP CHANCES
UNTIL WE GET CLOSER TO THE EVENT CONSIDERING THE 12Z ECMWF FOCUSES
THE PRECIP TO THE SOUTHWEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1254 PM CDT SUN AUG 10 2014
WE START THIS PERIOD WITH A WEAK COLD FRONT STRETCHING FROM A SFC
LOW NEAR LONG PRAIRIE SOUTH TO BETWEEN REDWOOD FALLS AND NEW ULM.
SOME CLEARING THIS MORNING AHEAD OF THE BOUNDARY ALLOWED FOR
ENOUGH INSTABILITY TO DEVELOP TO GET THE SCT LINE OF SHOWERS
THAT WE ARE SEEING NOW. THIS LINE OF SHRA AND EVENTUALLY TSRA WILL
SPREAD EAST THIS AFTERNOON...REACHING THE TWIN CITIES AFTER 21Z.
THE HRRR HAS HAD A GOOD HANDEL ON THE ACTIVITY TODAY...AND
CONTINUED TO FOLLOW IT FOR TIMING -SHRA AT TERMINALS. THIS
ACTIVITY LOOKS TO BE MAINLY DIURNALLY DRIVEN...WHICH MEANS NOT
MUCH LOOKS TO BE LEFT BY THE TIME THIS ACTIVITY WOULD REACH
EAU...SO LEFT THAT TAF DRY. TONIGHT...MODELS SHOW MVFR CIGS
DEVELOPING IN THE WAKE OF THE FRONT...ESPECIALLY UP TOWARD DLH.
BASED MVFR CIGS IN TAFS ON A NAM/RAP BLEND...THOUGH THERE ARE STILL
QUESTIONS AS TO HOW FAR SOUTH AND EXTENSIVE THESE MVFR CIGS WILL
BE. FINALLY...BEHIND THE FRONT...NAM SOUNDINGS CONSISTENT WITH
SHOWING GUSTY NNW WINDS DEVELOPING ONCE MIXING KICKS IN.
KMSP...CONVECTION WAS BEGINNING TO FIRE ALONG THE BOUNDARY WEST OF
THE CITIES...AND CONFIDENCE IS HIGH IN SCT SHRA/TSRA BEING WITHIN
THE METRO AREA BETWEEN 22Z AND 02Z. HAVE LOW TO MODERATE
CONFIDENCE ON MVFR CIGS OVERNIGHT...BUT IF WE DO SEE ANY...THEY
SHOULD BE ALL BUT OUT OF HERE BY 12Z. AFTER THAT...SKIES MONDAY
WILL BE CLEARING THROUGH THE DAY...WITH NNW GUSTING TO BETWEEN 20
AND 25 KTS BY LATE MORNING.
/OUTLOOK FOR KMSP/
TUE...VFR. WINDS NW 5-10 KTS.
WED...VFR. WINDS W 5-10 KTS.
THU...VFR. WINDS SE 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...JRB
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
114 PM CDT SUN AUG 10 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 255 AM CDT SUN AUG 10 2014
REGIONAL RADAR/SATELLITE AND SFC OBS ALL INDICATED THAT A WEAK STORM
SYSTEM CONTINUED TO SLOWLY MIGRATE N/NE ACROSS WC MN...WITH AREAS OF
HEAVY RAINFALL SPINNING COUNTER-CLOCKWISE AROUND IT. SOME AREAS
ACROSS WC MN HAD OVER 2 TO 3 INCHES OF RAINFALL SINCE SATURDAY
EVENING. ALTHOUGH RAINFALL INTENSITY HAS DIMINISHED SINCE
MIDNIGHT...THAT HAS BEEN A STRENGTHENING TREND OF SOME OF THE
RETURNS ACROSS SE SD WHICH WILL LIKELY MOVE INTO SW/WC MN THRU
SUNRISE.
HOW FAR EASTWARD THE HEAVIER SHRA MOVE THRU NOON TODAY REMAINS THE
BIG QUESTION BASED ON VERY LITTLE MOVEMENT OF THE UPPER LOW AND
ANOTHER STRONGER WX SYSTEM MOVING ACROSS IA/MO/KS...TAKING SOME OF
THE MOISTURE AND ENERGY FROM THE NORTHERN SYSTEM. AS WITH THE
PREVIOUS EARLY MORNINGS THE PAST FEW DAYS...SHRA/TSRA SEEM TO
REGENERATE NEAR THE UPPER LOW WHICH WILL LEAD TO HIGHER POPS ACROSS
CENTRAL MN THRU NOON. ELSEWHERE...ESPECIALLY ACROSS WC WI...CHC OF
SHRA/TSRA WILL REMAIN LIMITED UNTIL THE MAIN SHRTWV AND SFC FRONT
MOVES ACROSS THE AREA LATER THIS EVENING/OVERNIGHT.
WITH PWATS VERY HIGH AND THE SLOW MOVEMENT OF THE CONVECTION...HAVE
LEAN TOWARD HEAVY RAINFALL AS THE MAIN THREAT TODAY/TONIGHT. SHEAR
VALUES AND THE LACK OF SUNSHINE TODAY WILL LIMIT THE SVR WX THREAT.
AS THE MAIN SHRTWV MOVES THROUGH AND THE SFC FRONT MOVES EAST OF MPX
CWA...THE CHC/S OF RAINFALL WILL DIMINISH SIGNIFICANTLY AFT MIDNIGHT
TONIGHT. TEMPS ARE THE REFLECTION OF MORE CLOUD COVER AND SCATTERED
SHRA/TSRA IN THE AREA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 255 AM CDT SUN AUG 10 2014
OVERALL WE/LL SEE THINGS SHIFT FROM A HIGHLY AMPLIFIED UPPER LEVEL
PATTERN AT THE START OF THE PERIOD TO A MORE ZONAL PATTERN BY THE
END OF THE WEEK. CHANCES FOR PCPN WILL MAINLY BE TIED TO THE
DEPARTING SHORTWAVE AND FRONTAL BOUNDARY MONDAY... THEN WARM
ADVECTION AND AN APPROACHING SHORTWAVE TOWARD THE END OF THE
PERIOD. THE GFS AND ECMWF HAVE SLOWED THEIR PROGRESSION OF
FEATURES LATER IN THE WEEK IN COMPARISON TO THEIR PREVIOUS RUNS...
WHICH MAKES SENSE GIVEN THE AMPLIFYING EASTERN TROUGH/CUTOFF LOW
IN THE TUESDAY-THURSDAY TIME FRAME. WOULDN/T BE SURPRISED TO SEE
SUBSEQUENT RUNS SLOW THINGS FURTHER. SLOWED/REDUCED POPS IN THE
LATER PERIOD TO REFLECT THIS EXPECTATION FOR THE LARGE SCALE FLOW
AND TREND IN THE GUIDANCE.
WE/LL PROBABLY STILL HAVE SOME SHRA/TSRA OVER THE EASTERN PORTION
OF THE AREA ON MONDAY AS THE FRONTAL BOUNDARY SLOWLY MOVES EAST
AND THE MID-UPPER LEVEL COLD POOL SLIDES ACROSS THE AREA.
SUFFICIENT RIDGING AND LOW LEVEL ANTICYCLONIC FLOW LOOKS TO ARRIVE
MONDAY NIGHT TO BRING AN AND TO ANY LINGERING PCPN ACROSS THE
EASTERN PORTION OF THE AREA. WE SHOULD THEN SEE DRY WEATHER
PREVAIL INTO THE LATER HALF OF THE WEEK AS WE SIT ON THE BACKSIDE
OF THE UPPER TROUGH IN NORTHWEST FLOW AND THE SURFACE HIGH
GRADUALLY SLIDES EAST. RETURN FLOW/WARM ADVECTION WILL BEGIN TO
SETUP ON THURSDAY... BUT IT DOESN/T APPEAR THAT WE/LL SEE TOO MUCH
IN THE WAY OF MOISTURE RETURN AND ISENTROPIC LIFT UNTIL SATURDAY.
INTRODUCED SOME POPS INTO THE WEST/SOUTH THURSDAY INTO FRIDAY...
BUT KEPT MUCH OF THE AREA DRY UNTIL SATURDAY WHEN IT FINALLY
APPEARS THAT WE/LL SEE MORE ROBUST WARM ADVECTION AND CONVECTIVE
INSTABILITY MOVE INTO THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1254 PM CDT SUN AUG 10 2014
WE START THIS PERIOD WITH A WEAK COLD FRONT STRETCHING FROM A SFC
LOW NEAR LONG PRAIRIE SOUTH TO BETWEEN REDWOOD FALLS AND NEW ULM.
SOME CLEARING THIS MORNING AHEAD OF THE BOUNDARY ALLOWED FOR
ENOUGH INSTABILITY TO DEVELOP TO GET THE SCT LINE OF SHOWERS
THAT WE ARE SEEING NOW. THIS LINE OF SHRA AND EVENTUALLY TSRA WILL
SPREAD EAST THIS AFTERNOON...REACHING THE TWIN CITIES AFTER 21Z.
THE HRRR HAS HAD A GOOD HANDEL ON THE ACTIVITY TODAY...AND
CONTINUED TO FOLLOW IT FOR TIMING -SHRA AT TERMINALS. THIS
ACTIVITY LOOKS TO BE MAINLY DIURNALLY DRIVEN...WHICH MEANS NOT
MUCH LOOKS TO BE LEFT BY THE TIME THIS ACTIVITY WOULD REACH
EAU...SO LEFT THAT TAF DRY. TONIGHT...MODELS SHOW MVFR CIGS
DEVELOPING IN THE WAKE OF THE FRONT...ESPECIALLY UP TOWARD DLH.
BASED MVFR CIGS IN TAFS ON A NAM/RAP BLEND...THOUGH THERE ARE STILL
QUESTIONS AS TO HOW FAR SOUTH AND EXTENSIVE THESE MVFR CIGS WILL
BE. FINALLY...BEHIND THE FRONT...NAM SOUNDINGS CONSISTENT WITH
SHOWING GUSTY NNW WINDS DEVELOPING ONCE MIXING KICKS IN.
KMSP...CONVECTION WAS BEGINNING TO FIRE ALONG THE BOUNDARY WEST OF
THE CITIES...AND CONFIDENCE IS HIGH IN SCT SHRA/TSRA BEING WITHIN
THE METRO AREA BETWEEN 22Z AND 02Z. HAVE LOW TO MODERATE
CONFIDENCE ON MVFR CIGS OVERNIGHT...BUT IF WE DO SEE ANY...THEY
SHOULD BE ALL BUT OUT OF HERE BY 12Z. AFTER THAT...SKIES MONDAY
WILL BE CLEARING THROUGH THE DAY...WITH NNW GUSTING TO BETWEEN 20
AND 25 KTS BY LATE MORNING.
/OUTLOOK FOR KMSP/
TUE...VFR. WINDS NW 5-10 KTS.
WED...VFR. WINDS W 5-10 KTS.
THU...VFR. WINDS SE 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JLT
LONG TERM...
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
300 PM CDT Sun Aug 10 2014
.SHORT TERM...(This Evening through Monday)
Issued at 300 PM CDT SUN AUG 10 2014
Warm and humid conditions are in place across the region this
afternoon. Starting to see an uptick in convection during the
past hour, particularly across central Missouri. This is in
response to destabilization due to daytime heating and upper level
energy rotating around an area of low pressure located near Kansas
City. Water vapor imagery and RAP initializations of mid level
vorticity indicate multiple lobes of vorticity emanating from this
upper low. As a result, we should continue to see a gradual
increase in showers and storms across much of the Missouri Ozarks
heading into this evening. The aforementioned upper low and a cold
front moving into the region from the northwest will maintain
scattered showers and storms across the region into much of
tonight. Overnight the better rain chances should begin to shift
to the southeast and east.
High PW air in place (around 1.9" according to the SPC
mesoanalysis page) will result in locally heavy rainfall with this
activity. Deep layer shear remains on the weak side, around 25-30
kt, while both surface based and mixed layer CAPE values are
nearing 3000 J/kg. This should result in a mainly multicell
convective mode with an isolated risk for wet microbursts.
The cold front will exit to the east/southeast on Monday with rain
chances ending during the morning hours.
.LONG TERM...(Monday Night through Sunday)
Issued at 300 PM CDT SUN AUG 10 2014
A nice stretch of weather is expected across the area from Monday
night through Thursday as large area of Canadian surface high
pressure dominates our weather regime. Temperatures will some 7 to
10 degrees below average with comfortable humidity levels.
Temperatures and humidity will rebound back to typical mid-August
values late this week through next weekend as the upper level
pattern flattens a bit. Upper level ridging will attempt to build
into the region from the southwest, meanwhile energy in the
northern stream will threaten to enter from the northwest. Day to
day continuity from individual medium range models have been
lacking (one run wet, the next run dry), however the consensus
suggests that the door will be open to mesoscale convective
systems (MCS) entering from the northwest. As a result, have
continued low end chance PoPs from Friday through the weekend
until finer scale details can be resolved.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
Issued at 1202 PM CDT SUN AUG 10 2014
A generally low confidence forecast for the terminals this
afternoon and evening. Thunderstorms are expected to develop west
of JLN early to mid afternoon, and move and develop to the east and
southeast with time. Gusty winds and a drop to IFR can be expected
should a storm move over a terminal. Outside of TSRA, VFR
conditions will prevail. Some light fog and/or stratus development
is then expected late tonight, with conditions dropping at least
to MVFR, with some possibility of IFR. Improving conditions are
then expected tomorrow morning as drier air begins to move into
the region from the north.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...Gagan
LONG TERM...Gagan
AVIATION...Boxell
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
740 PM PDT MON AUG 11 2014
.SYNOPSIS...MONSOON MOISTURE PUSHING IN FROM THE SOUTHEAST WILL
RESULT IN INCREASED THUNDERSTORM COVERAGE THROUGH WEDNESDAY. DRIER
AIR WILL ONCE AGAIN GRADUALLY MOVE IN FROM THE SOUTHWEST STARTING
THURSDAY WITH THUNDERSTORM CHANCES CONFINED TO MOHAVE COUNTY BY
FRIDAY.
&&
.UPDATE...FORECAST TRENDS LOOK GOOD TONIGHT BASED ON RADAR TRENDS
AND HIGH RESOLUTION MODEL OUTPUT. NO CHANGES PLANNED AT THIS TIME.
&&
.PREV DISCUSSION...
325 PM PDT MON AUG 11 2014
.SHORT TERM...THROUGH TUESDAY NIGHT...
TAIL END OF LINE OF STORMS WHICH WAS OVER INYO/ESMERALDA COUNTY THIS
MORNING DID SHIFT EASTWARD AND DID AFFECT SRN NYE/CLARK COUNTIES
THIS AFTERNOON. THOSE STORMS NOW MOVING INTO LINCOLN COUNTY.
ACTIVITY IS GETTING GOING OVER MOHAVE COUNTY WITH
MORE STORMS SET TO ENTER MOHAVE COUNTY FROM COCONINO/YAVAPAI
COUNTIES. HRRR SUGGEST THE NORTHERN TWO-THIRDS OF MOHAVE COUNTY WILL
REMAIN THE MOST ACTIVE FOR THE NEXT 3-4 HOURS THEN SHIFTING
NORTHWARD ACROSS NORTHEAST CLARK AND LINCOLN COUNTIES THIS EVENING.
GUSTS OF 40-50 MPH...SMALL HAIL AND BRIEF HEAVY RAIN POSSIBLE WITH
STORMS.
FOR TUESDAY...MODELS MORE OR LESS IN GOOD AGREEMENT SHOWING AN
INVERTED TROUGH MOVING EAST ACROSS SOUTHERN ARIZONA TONIGHT AND INTO
SOUTHWEST ARIZONA LATE TUESDAY AFTERNOON. INVERTED TROUGH THEN
ENCOUNTERS A MORE WESTERLY FLOW AND LIFT NORTH ACROSS WESTERN
ARIZONA TUESDAY NIGHT/WEDNESDAY. DUE TO ADDITIONAL DYNAMICS DECIDED
TO ISSUE A FLASH FLOOD WATCH FOR THE NORTHWEST DESERT AND PLATEAU OF
MOHAVE COUNTY FROM 11 AM MST - 10 PM MST TUESDAY. TOMORROW WE WILL
BE LOOKING AT THE NEED OF EXTENDING THE WATCH INTO WEDNESDAY IF
MODELS STAY CONSISTENT.
.LONG TERM...WEDNESDAY THROUGH SUNDAY...THE SYNOPTIC PATTERN
FEATURES A LOW PRESSURE TROUGH OVER THE PACIFIC NW WEDNESDAY THAT IS
FORECAST TO MOVE INTO THE NORTHERN GREAT BASIN THURSDAY AND FRIDAY.
THE UPPER LEVEL FLOW BECOMES SOLIDLY WEST TO SOUTHWEST AS THE WEEK
WEARS ON. THE AFFECT OF THIS LARGE SCALE FEATURE ON SENSIBLE WEATHER
WITHIN THE FORECAST AREA IS TO BRING A DECREASING TREND IN
THUNDERSTORM COVERAGE.
WEDNESDAY HAS THE BEST POTENTIAL FOR SCATTERED THUNDERSTORMS ACROSS
A WIDER AREA INCLUDING LINCOLN, CLARK, MOHAVE AND EASTERN SAN BERN
COUNTIES. BEYOND WEDNESDAY, RAPID DRYING TAKES PLACE IF THE GFS
VERIFIES BUT COULD BE SOMEWHAT SLOWER PER THE ECMWF. MAINTAINED A
MENTION OF STORMS IN MOHAVE COUNTY BOTH THURSDAY AND FRIDAY BEFORE
DRYING THEM OUT COMPLETELY OVER THE WEEKEND. TEMPERATURES WILL
GENERALLY BE BELOW NORMAL MID TO LATE IN THE WEEK THEN BECOME
SEASONAL OVER THE WEEKEND.
.AVIATION...FOR MCCARRAN...OUTFLOW WINDS FROM SURROUNDING STORMS
WILL CONTINUE TO AFFECT LAS VEGAS VALLEY TERMINALS INTO THE EVENING
HOURS. LOOKS LIKE WINDS WILL FAVOR A NORTHERLY DIRECTION FOR SEVERAL
HOURS BEFORE TRANSITION BACK TO OUR TYPICAL SOUTH/SOUTHWEST
DIRECTION WITH SPEEDS OF 7-11 KTS. CONVECTION SHOULD IMPACT MAINLY
THE BEATTY...MORMON MESA AND PEACH SPRINGS CORRIDORS THIS EVENING.
THERE WILL BE ANOTHER CHANCE OF SHOWERS OR TSTORM WITHIN THE
VICINITY OF THE TERMINAL TUESDAY...WHICH COULD BRING GUSTY AND
ERRATIC WINDS.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SCATTERED-BROKEN CLOUDS ALONG WITH ISOLATED TO
SCATTERED THUNDERSTORMS ACROSS ALL OF SOUTHEAST
CALIFORNIA...SOUTHERN NEVADA AND NORTHWEST ARIZONA THIS EVENING AND
AGAIN TUESDAY. WINDS WILL FAVOR TYPICAL DIURNAL WIND PATTERNS
THROUGH TUESDAY...EXCEPT NEAR THUNDERSTORMS.
.SPOTTER INFORMATION STATEMENT...SPOTTERS SHOULD REPORT INSTANCES OF
FLASH FLOODING...STRONG GUSTY WINDS...HAIL...AND BLOWING DUST TODAY
THROUGH TUESDAY.
&&
$$
UPDATE...MORGAN
SHORT TERM/AVIATION...PIERCE
LONG TERM...SALMEN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS RALEIGH NC
910 PM EDT MON AUG 11 2014
.SYNOPSIS...HIGH PRESSURE WILL GRADUALLY MOVE NORTHEAST AWAY FROM
THE REGION...AS A WARM FRONT SLOWLY MOVES NORTH OVER THE CAROLINAS
THROUGH THE DAY TUESDAY. A COLD FRONT FOLLOWS QUICKLY FROM THE
NORTHWEST TUESDAY NIGHT INTO WEDNESDAY. HIGH PRESSURE MOVES OVER
MOST OF THE REGION FROM THE WEST WEDNESDAY AND WEDNESDAY NIGHT WITH
DRIER AIR FOR THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM MONDAY...
CERTAINLY A FAIR AMOUNT OF LOW-LEVEL DRYING TOOK PLACE IN CENTRAL
NORTH CAROLINA TODAY...ENOUGH TO RESULT IN AMPLE WARMING AND MORE OF
A CONVECTIVE APPEARANCE TO PRECIPITATION IN MOST PLACES AS OPPOSED
TO STRATIFORM...WITH THE POSSIBLE EXCEPTION OF THE IMMEDIATE TRIAD
TOWARD KINT. THERE WAS LIMITED LIGHTNING WITH THE CONVECTION...
OUTSIDE OF A STRIKE OR TWO SOUTH OF KLBT. SCATTERED-TO-NUMEROUS
SHOWERS WILL CONTINUE FOR THE LATE AFTERNOON INTO THE EVENING...
WITH ENOUGH INSTABILITY MAINLY SOUTH OF U.S. 64...WHERE THE SPC
MESOANALYSIS NOTES AROUND 500J/KG...TO PROVIDE FOR A CHANCE OF A
THUNDERSTORM. DURING THE EVENING HOURS...INCREASING STABILITY TAKING
PLACE DIURNALLY ALONG WITH THE BETTER MOISTURE AXIS BEING LOCATED
CLOSER TO THE NORTHWEST PIEDMONT WILL RESULT IN HIGHER CHANCES OF
SHOWERS IN THE WESTERN PIEDMONT AND ESPECIALLY TOWARD THE IMMEDIATE
TRIAD BY THE OVERNIGHT HOURS. EAST OF U.S. 1 LATE TONIGHT...WHILE
RETAINING A SMALL CHANCE FOR PRECIPITATION...MUCH OF THE GUIDANCE
INCLUDING THE HRRR WRF SUGGESTS LITTLE TAKING PLACE. CLOUDS SHOULD
LOWER AND THE OVERALL AIR MASS MOISTEN OVERNIGHT AS THE SURFACE HIGH
STARTS TO RETREAT AND THE SURFACE FRONT TO OUR SOUTH MOVES NORTH.
OVERNIGHT LOWS AROUND 70.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 300 PM MONDAY...
AS THE SURFACE HIGH CONTINUES TO RETREAT AND SURFACE LOW PRESSURE
MOVES NORTH ALONG THE COAST...THE SURFACE WARM FRONT SHOULD SLOWLY
MOVE NORTH. THE NAM IS FARTHER EAST WITH THE SURFACE LOW COMPARED TO
THE GFS...WHICH BRINGS WEAK SURFACE LOW PRESSURE RIGHT THROUGH
CENTRAL NORTH CAROLINA. THE GFS PATTERN IS SOMEWHAT CONCERNING...
WITH LOW LCL HEIGHTS ANTICIPATED ALONG WITH MODEST INSTABILITY BY
AFTERNOON...1000J/KG FROM THE 0-1KM LEVEL. HOWEVER...ITS 0-3KM
HELICITY FORECAST IS UNDER 100M2/S2 WITH ONLY MODEST 1000-500MB
LAPSE RATES AROUND 6C/KM AND 0-3KM SHEAR IS IN THE TEENS KNOTS AT
BEST. AFTER ANY MORNING LOW CLOUDS SHOULD START TO LIFT...BUFR
SOUNDINGS SHOW ENOUGH INSTABILITY FOR CU AND GENERALLY SKINNY CAPE
FOR SCATTERED SHOWERS AND THUNDERSTORMS. AS THE WARM FRONT IS
LOCATED BY THE GFS AND THE NAM MAINLY NORTH OF U.S. 64 BY
AFTERNOON...THE FORECAST LIFT OF THE NAM AND THE GFS IS HIGHEST FROM
THE TRIANGLE NORTH AND NORTHEAST. SHOULD THERE BE A STRONG
THUNDERSTORM...IT MAY BE THERE WHERE THE POTENTIAL IS HIGHEST.
DAYTIME HIGHS TUESDAY ARE ANOTHER CHALLENGE DEPENDING ON THE DEGREE
OF CLOUD COVER AND ESPECIALLY CU IN THE AFTERNOON...BUT WILL LEAN
TOWARD THE WARMER MAV GUIDANCE THOUGH NOT GOING QUITE THAT HIGH...
HIGHS 80 TO 85 IN THE TRIAD AND MID TO UPPER 80S ELSEWHERE.
TUESDAY NIGHT THE COLD FRONT STARTS TO MOVE INTO CENTRAL NORTH
CAROLINA FROM THE NORTHWEST. BUFR SOUNDINGS FROM BOTH THE NAM AND
THE GFS ACTUALLY FORECAST BRIEF LAYER WARMING BETWEEN 700MB AND
500MB BEFORE THE NAM IN PARTICULAR FORECASTS BRIEF COOLING IN THAT
LAYER ALONG AND AHEAD OF THE COLD FRONT. USING K INDICES AS A PROXY
FOR THE ACTUAL FRONT...AS THOSE VALUES GO QUICKLY NEGATIVE BEHIND
THE FRONT...THE FRONT SHOULD MOVE THROUGH THE TRIAD AROUND 06Z
WEDNESDAY AND THROUGH THE TRIANGLE AND JUST EAST OF U.S. 1 BY 12Z.
WILL RETAIN SOME CHANCES FOR PRECIPITATION UNTIL FRONTAL PASSAGE.
OVERNIGHT LOWS IN THE MID 60S IN THE TRIAD AND WITHIN A DEGREE OR
THREE OF 70 ELSEWHERE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...
A TRANQUIL WEATHER PATTERN EXPECTED IN THE LONG TERM. TEMPERATURES
WILL REMAIN NEAR OR BELOW NORMAL.
A L/W TROUGH ANCHORED BY AN UPPER LEVEL LOW OVER ONTARIO/QUEBEC WILL
EXTEND SOUTHWARD INTO THE CAROLINAS THROUGH FRIDAY. THE LEAD COLD
FRONT ASSOCIATED WITH THE TROUGH WILL EXIT OUR COASTAL PLAIN
COUNTIES WEDNESDAY MORNING. MODEL TREND HAS LEANED TOWARD A SLIGHTLY
FASTER EAST PROGRESSION. THUS HAVE TRIMMED THE BACKSIDE OF THE
SLIGHT POPS...KEEPING THE 20 PERCENT POPS CONFINED TO LOCATIONS
ALONG AND EAST OF I-95 AT 6 AM...WITH NEGLIGIBLE POPS BY 10 AM.
WESTERLY LOW LEVEL FLOW IN THE WAKE OF THE FRONT WILL AID TO
DIMINISH/DISSIPATE CLOUD COVERAGE IN THE MORNING...LEADING TO MOSTLY
SUNNY SKIES AREAWIDE BY EARLY AFTERNOON. IT SHOULD BE NOTICEABLY
LESS HUMID ACROSS MICH OF THE PIEDMONT BY EARLY-MID AFTERNOON...AND
INTO THE SANDHILLS AND COASTAL PLAIN LATE IN THE DAY. INITIAL SURGE
OF LOW LEVEL CAA WILL BE NEGATED SOMEWHAT BY DOWNSLOPE COMPONENT OF
LOW LEVEL FLOW AND MID-AUGUST SUN. MAX TEMPS IN THE MID 80S NW TO
UPPER 80S/AROUND 90 SE.
SOME DOUBT AS TO WHETHER NEAR SURFACE WINDS WILL BE ABLE TO DECOUPLE
AS A SECONDARY SFC FRONT WILL APPROACH FROM THE W-NW LATE WEDNESDAY
NIGHT-EARLY THURSDAY. IF ATMOSPHERE REMAINS WELL MIXED...MOST PLACES
SHOULD SEE MIN TEMPS NO LOWER THAN 60-65 DEGREES (NW-SE). IF WINDS
DECOUPLE...NORMALLY COLDER LOCATIONS MY DIP BELOW 60.
A CANADIAN HIGH PRESSURE SYSTEM AT THE SURFACE WILL BE CENTERED OVER
THE LOWER OH VALLEY AND TN VALLEY THURSDAY AND FRIDAY. THIS WEATHER
SYSTEM WILL MAINTAIN DRY CONDITIONS WITH TEMPS GENERALLY A FEW
DEGREES SHY OF NORMAL. THICKNESSES SUPPORT MAX TEMPS IN THE LOW-MID
80S THURSDAY...AND SOLIDLY IN THE MID 80S FRIDAY. BETTER CHANCE FOR
THE NEAR SURFACE WINDS TO DECOUPLE THURSDAY NIGHT. IF SKIES REMAIN
CLEAR...SHOULD SEE MIN TEMPS IN THE UPPER 50S-LOWER 60S. AIR MASS
MODIFICATION FRIDAY NIGHT SUGGEST MIN TEMPS IN THE LOW-MID 60S.
SURFACE HIGH PRESSURE WILL SETTLE OVERHEAD SATURDAY THEN SLOWLY
WEAKEN AS L/W TROUGH WEAKENS AND LIFTS NWD. THIS WILL ALLOW A WEAK
RETURN OF LOW LEVEL MOISTURE BY LATE SATURDAY AND MORE SO SUNDAY
INTO MONDAY. THIS WILL LEAD TO MIXTURE OF SUN/CLOUDS BUT ANY
CONVECTIVE ACTIVITY WILL BE ISOLATED AND CONFINED TO NEAR THE
SEABREEZE...AND EXITING OFF THE HIGHER TERRAIN OF WESTERN NC.
THREAT APPEARS TOO LOW TO MENTION A SLIGHT CHANCE POP ON SUNDAY BUT
ENOUGH MOISTURE/DESTABILIZATION SHOULD EXISTS BY MONDAY FOR SLIGHT
CHANCE IN VICINITY OF THE OUR SOUTHERN AND WESTERN COUNTIES.
AIR MASS WILL CONTINUE TO MODIFY WITH TEMPS RETURNING TO NEAR NORMAL
LEVELS SATURDAY THROUGH MONDAY.
&&
.AVIATION /00Z MONDAY THROUGH SATURDAY/...
AS OF 840 PM MONDAY...
AN AREA OF GENERALLY LIGHT SHOWERS WILL CONTINUE TO DECREASE IN
COVERAGE AN INTENSITY THIS EVENING WITH THE LOSS OF DAYTIME HEATING.
KRDU AND KFAY STAND THE BEST CHANCE OF SEEING SOME SHOWER ACTIVITY
THROUGH 03Z OR SO. MVFR/IFR CONDITIONS WILL BE POSSIBLE WITH THE
SHOWERS... AND NEAR THE SHOWERS. OTHERWISE... EXPECT CIGS AND VISBYS
WILL BEGIN TO LOWER OVERNIGHT WITH LOW LEVEL SOUTH TO SOUTHEASTERLY
FLOW. GENERALLY EXPECT IFR CONDITIONS... WITH THE HIGHEST
CONFIDENCES OF IFR CONDITIONS ACROSS AT KGSO/KINT. KGSO/KINT STAND
THE BEST CHANCE OF SEE SOME LINGERING PRECIP AFTER MIDNIGHT WITH
WITH THE GENERAL LOW LEVEL FLOW INTO THE HIGHER TERRAIN. CIGS WILL
BE SLOW TO RISE ON TUESDAY MORNING. SUB-VFR CONDITIONS ARE EXPECTED
TO LINGER THE LONGEST IN THE TRIAD (KGSO/KINT)... POSSIBLY NEVER
MAKING IT TO VFR. SHOWERS AND A FEW THUNDERSTORMS WILL BE POSSIBLE
ON TUESDAY LATE MORNING INTO THE AFTERNOON AS A COLD FRONT
APPROACHES THE AREA. SUB-VFR CONDITIONS WILL BE POSSIBLE WITH THE
SCATTERED SHOWERS AND STORMS.
THE COLD FRONT IS EXPECTED TO MOVE THROUGH THE AREA VERY LATE
TUESDAY INTO WEDNESDAY MORNING. THE PASSAGE OF THIS FRONT SHOULD END
THE HIGHER PROBABILITY OF SUB-VFR CONDITIONS FOR THE REST OF THE
WORK WEEK AND INTO SATURDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF
LONG TERM...WSS
AVIATION...BSD/DJF
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
342 PM EDT SUN AUG 10 2014
.SYNOPSIS...
A STALLED FRONT WILL MEANDER ACROSS THE AREA THROUGH LATE MONDAY.
AREAS OF LOW PRESSURE WILL AT TIMES DEVELOP AND MOVE ALONG THIS
BOUNDARY AND OFFSHORE. THIS WILL BRING A PERIOD OF UNSETTLED WEATHER
WITH SHOWERS AND A FEW THUNDERSTORMS. WITH A SATURATED AIR MASS
ACROSS THE REGION...THE RAINFALL MAY BE HEAVY AT TIMES. THIS FRONT
WILL FINALLY MOVE OUT OF THE AREA BY TUESDAY AS A STRONG COLD
APPROACHES FROM THE NORTHWEST AND PASSES THROUGH THE AREA BY
THURSDAY BEFORE STALLING OFF THE COAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM SUNDAY...MODERATE TO HEAVY RAINFALL CONTINUES TO
BLOSSOM OVER SC COASTAL COUNTIES. HI RESOLUTION HRRR AND RUC
CONTINUE TO FAVOR SOME OF THESE AREAS FOR CONTINUED RAIN OVER THE
NEXT SEVERAL HOURS AND IN SOME CASES EVEN THROUGH SOME OF THE
OVERNIGHT HOURS. FLOOD WATCH WILL REMAIN IN EFFECT FOR NOW. HAVE
ALSO CHOSEN TO LEAVE THE WATCH IN EFFECT FOR THE NC COAST AS WELL
MANY PLACES WERE HIT HARD ENOUGH YESTERDAY TO STILL BE VERY
SENSITIVE TO ANY ADDITIONAL RAINFALL. AND WHILE SYNOPTIC SCALE
MODELS TEND TO KEEP MOST OF THE WET WEATHER SOUTH THE RUC AND HRRR
ALSO SHOWS SOME REDEVELOPMENT IN THESE LOCALES LATER ON. GIVEN THAT
A DECENT SHORTWAVE IS PROGGED TO SLIDE JUST BY TO OUR NORTH LATE
TONIGHT THIS SEEMS PLAUSIBLE. MOST PLACES WILL HAVE A LOW CLOSE TO
70...SAVE FOR IN PLACES WHERE HIGHER DEWPOINTS PREVENT A FURTHER
DROP...AND SOME OF THESE PLACES MAY NEED TO HAVE FCST RAISED A BIT.
LAST NIGHT THERE WAS SOME VERY ISOLATED FOG DESPITE LOW CLOUDS AND A
LITTLE WIND. THIS IS CERTAINLY POSSIBLE AGAIN...BUT ONCE AGAIN
SHOULD BE ISOLATED ENOUGH TO PRECLUDE BEING IN ANY FORECASTS AT THIS
POINT.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...A FRONTAL BOUNDARY WILL LINGER OVER THE AREA
INTO TUESDAY BEFORE LIFTING NORTHWARD IN ADVANCE OF A COLD FRONT
APPROACHING FROM THE NORTHWEST. THESE BOUNDARIES AND PASSING WEAK
IMPULSES ALOFT...WILL INTERACT WITH A WARM...MOIST AIR MASS TO
PRODUCE SCATTERED TO NUMEROUS SHOWERS THROUGH THE PERIOD...WITH A
HIGHER PROBABILITY OF THUNDERSTORMS FOR TUESDAY AND TUESDAY NIGHT
DUE TO A DECREASE IN CLOUD COVER. HIGH TEMPERATURES MONDAY WILL
REACH THE LOW TO MID 80S WITH MID 80S TO AROUND 90 POSSIBLE TUESDAY.
MINS EACH NIGHT WILL BE IN THE 70 TO 75 DEGREE RANGE.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 3 PM SUNDAY...AS HAS BEEN THE TREND RECENTLY A COLD FRONT WILL
MOVE INTO THE REGION BEFORE THE LACK OF MID LEVEL PUSH ENDS UP
STALLING THE BOUNDARY IN THE VICINITY. DEEP WESTERLY FLOW DEVELOPS
AS THE FRONT MOVES INTO THE REGION AND THEN OFF THE COAST WED. WARM
ADVECTION AHEAD OF THE FRONT ALONG WITH MID LEVEL DRYING/HEATING AND
WESTERLY FLOW BEHIND THE FRONT WILL PUSH HIGHS INTO THE LOWER 90S.
THERE WILL BE A CHANCE OF ISOLATED AFTERNOON CONVECTION...BUT MID
LEVEL DRYING WILL KEEP COVERAGE LIMITED TO CHC AT BEST WITH SLIGHT
CHC PROBABLE FARTHER INLAND.
REMAINDER OF THE FORECAST IS A LITTLE MORE QUESTIONABLE. WEAK FLAT
5H TROUGH AND LACK OF STRONG SURFACE HIGH WILL KEEP THE FRONT
STALLED OFF THE COAST INTO THE START OF NEXT WEEK. THERE IS LIKELY
TO BE A SHARP CONTRAST BETWEEN DEEP MOISTURE AND VERY DRY MID
LEVELS. WEAK WAVES OF LOW PRESSURE TRAVELING ALONG THE FRONT
COMPLICATE POSITIONING THE BOUNDARY ON A DAY BY DAY BASIS. FOR NOW
WILL CARRY A FORECAST WITH A DIURNAL SILENT POP FOR MUCH OF THE
EXTENDED BUT WITH THE CAVEAT THAT ANY OF THESE DAYS COULD END UP WET
GIVEN THE UNCERTAINTY WITH RESPECT TO THE STALLED BOUNDARY AND THE
DEEP MOISTURE. IF THE FRONT STAYS OFF THE COAST TEMPERATURES WILL
END UP NEAR CLIMO. ANY DAY WHERE THE FRONT MOVES CLOSER TO THE COAST
HIGHS COULD RUN NEAR TO BELOW CLIMO WHILE LOWS RUN SLIGHTLY ABOVE
CLIMO.
&&
.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
AS OF 18Z...IFR VSBYS/CIGS ARE OCCURRING AT KFLO/KLBT THIS AFTERNOON
WITH TEMPO SHOWERS AT KFLO. AT THE COASTAL TERMINALS IT WAS
VFR/TEMPO MVFR WITH SHOWERS INCREASING. MOST OF THE SHRA IS
LIGHT...EXCEPT THERE ARE ISOLATED SHOWERS WITH MDT-HVY RAINFALL. NO
LIGHTNING STRIKES ARE BEING DETECTED.
AT KLBT THERE IS MODERATE TO HIGH CONFIDENCE OF CIGS IMPROVING TO
MVFR THIS AFTERNOON. LATER THIS AFTERNOON THERE IS A GOOD CHANCE OF
VFR CIGS AT KLBT. AT KFLO CIGS/VSBYS COULD REMAIN IFR THROUGH MUCH
OF THE AFTERNOON WITH ONLY TEMPO IMPROVEMENT TO MVFR. AT THE COASTAL
TERMINALS TEMPO MVFR VSBYS IN SHOWERS CAN BE EXPECTED...BUT BRIEF
IFR VSBYS COULD OCCUR IN THE HEAVIER SHOWERS. SHOWERS SHOULD TEND TO
DISSIPATE NEAR KILM MID-LATE AFTERNOON WITH THE BEST POTENTIAL
SHIFTING TO THE KCRE/KMYR TERMINALS. SHRA/ISOLATED TSRA SHOULD
DISSIPATE SOUTHERN TERMINALS THIS EVENING.
OVERNIGHT EXPECT MAINLY MVFR VSBYS/CIGS AT THE COASTAL TERMINALS
WITH IFR VSBYS/TEMPO LIFR CIGS AT THE INLAND TERMINALS. MONDAY
MORNING THERE APPEARS TO BE A GOOD CHANCE OF MVFR CONDITIONS WITH
SHOWERS AT THE COASTAL TERMINALS.
EXTENDED OUTLOOK...ISOLATED TO SCATTERED SHRA/TSRA ALONG WITH TEMPO
MVFR CONDITIONS THROUGH TUESDAY AS A FRONT REMAINS STALLED IN THE
AREA. IMPROVING CONDITIONS WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM SUNDAY...COLD FRONT TO OUR SOUTH WILL MAKE A LITTLE
NORTHWARD PROGRESS THROUGH THE PERIOD AS A FLAT WAVE OF LOW PRESSURE
MOVES BY. THIS WILL KEEP CONDITIONS FAIRLY UNCHANGED ACROSS MOST OF
THE REGION. ONSHORE WINDS EXPECTED THROUGH THE PERIOD. A SLIGHT
PINCH IN THE GRADIENT WILL BE MAINTAINED ACROSS NORTHERN ZONES AND
EXTEND A LITTLE INTO NEW HANOVER CTY WATERS. SEAS WILL RUN 2 TO 3
FT...HIGHEST NORTH.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...E TO SE WINDS OF 10 TO 15 KT MONDAY AND MONDAY
NIGHT WILL BECOME SW ON TUESDAY AND CONTINUE TUESDAY NIGHT. SEAS OF
2 TO 3 FT WILL GRADUALLY INCREASE THROUGH THE PERIOD...REACHING 3 TO
4 FT TUESDAY WITH A FEW 5 FOOTERS POSSIBLE TUESDAY NIGHT. SCATTERED
SHOWERS AND THUNDERSTORMS ARE POSSIBLE THROUGH THE PERIOD.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 3 PM SUNDAY...WELL DEFINED SOUTHWEST FLOW AT THE START OF THE
PERIOD WILL BECOME LIGHT AND VARIABLE THU AND FRI AS FRONT STALLS
OVER OR JUST SOUTH OF THE WATERS. AHEAD OF THE FRONT GRADIENT WILL
KEEP FLOW IN THE 10 TO 15 KT RANGE WITH SEAS RUNNING 3 TO 5 FT. ONCE
THE FRONT PASSES OFFSHORE FLOW WILL DEVELOP...BUT WEAK GRADIENT WILL
KEEP SPEEDS 10 KT OR LESS FOR MUCH OF THE PERIOD. WEAK COLD SURGE
EARLY THU COULD PUSH SPEEDS TO 10 TO 15 KT FOR A BRIEF PERIOD OF
TIME. LIGHT GRADIENT WILL ALLOW DEVELOPMENT OF WEAK SEA BREEZE THU
AND FRI AND ONSHORE FLOW NEAR THE COAST MAY CREEP TO 10 TO 15 KT
EACH AFTERNOON. SEAS WILL RUN 2 TO 3 FT THU AND FRI DUE TO LIGHT
WINDS AND LIMITED SWELL.
&&
.TIDES/COASTAL FLOODING...
AS OF 5 AM SUNDAY...HIGH ASTRONOMICAL TIDES WILL BRING HIGH SURF
RUN-UP ON AREA BEACHES WITH TONIGHTS HIGH TIDE IN THE MID EVENING.
WITH A SLIGHT LAG-TIME THIS WILL ALSO BRING FLOODING TO PORTIONS
OF THE LOWER CAPE FEAR RIVER INCLUDING THE DOWNTOWN WILMINGTON
AREA. FOR THIS REASON A COASTAL FLOOD ADVISORY HAS BEEN ISSUED.
TIDAL DECLINES ARE PREDICTED MONDAY ONWARD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FLOOD WATCH THROUGH THIS EVENING FOR SCZ017-023-024-032-033-
039-053>056.
COASTAL FLOOD ADVISORY FROM 7 PM TO 10 PM EDT THIS EVENING FOR
SCZ054-056.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ087-096-099-105>110.
COASTAL FLOOD ADVISORY FROM 7 PM TO 10 PM EDT THIS EVENING FOR
NCZ106-108-110.
COASTAL FLOOD ADVISORY FROM 9 PM THIS EVENING TO 1 AM EDT
TONIGHT FOR NCZ107.
MARINE...NONE.
&&
$$
NEAR TERM...MBB
SHORT TERM...31
LONG TERM...TRL
AVIATION...MRR
TIDES/COASTAL FLOODING...8
AREA FORECAST DISCUSSION
NWS RALEIGH NC
200 PM EDT SUN AUG 10 2014
.SYNOPSIS...A SURFACE FRONT REMAINS NEARLY STATIONARY ACROSS SOUTH
CAROLINA THROUGH MONDAY AS HIGH PRESSURE EXTENDS SOUTHEAST ACROSS
THE MID ATLANTIC STATES. HIGH PRESSURE RETREATS NORTHEAST MONDAY
NIGHT INTO TUESDAY AS A WARM FRONT ALSO MOVES NORTHEAST. A COLD
FRONT THEN MOVES THROUGH THE REGION FROM THE NORTHWEST WEDNESDAY
INTO EARLY THURSDAY.
&&
.NEAR TERM /THIS AFTERNOON AND TONIGHT/...
AS OF 1235 PM SUNDAY...
AREAS OF LIGHT RAIN AND DRIZZLE CONTINUED ACROSS PART OF CENTRAL
NORTH CAROLINA EARLY THIS AFTERNOON IN A MOIST AIR MASS ALONG AND
NEAR AN 850MB BOUNDARY NEAR THE SOUTH CAROLINA BORDER...NORTH OF THE
SURFACE FRONT WELL SOUTH THROUGH MUCH OF SOUTH CAROLINA. THE LATEST
SURFACE ANALYSIS SHOWED HIGH PRESSURE AT THE SURFACE NOSED IN
THROUGH THE AREA...WITH SOME CLEARING ON THE VISIBLE SATELLITE
IMAGERY OVER THE NORTHERN COASTAL PLAIN WHERE TEMPERATURES AT
KIXA...FOR EXAMPLE...HAD RISEN CLOSE TO 80 DEGREES. THE LATEST RAP
SOUNDINGS INDICATE THE CONTINUED EXPECTATION OF CONSIDERABLE CLOUDS
OVER MUCH OF CENTRAL NORTH CAROLINA...WITH ENOUGH CLEARING NORTHEAST
THAT TEMPERATURES SHOULD RISE TO HIGHS IN THE LOWER 80S.
FLASH FLOOD GUIDANCE IS TWO INCHES OR GREATER OVER THREE HOURS...AND
THE DEVELOPMENT OF ANY HEAVY RAIN SEEMS TO MORE LIKELY LIE OVER
SOUTH CAROLINA...POSSIBLY WITH SOME POCKETS OF HEAVY SHOWERS NEAR
THE SOUTH CAROLINA BORDER IF THE HRRR WRF VERIFIES. HOWEVER...IN
SOME OF THOSE LOCATIONS THE RAIN ON SATURDAY WAS LIGHT COMPARED TO
OTHERS IN CENTRAL NORTH CAROLINA. COORDINATED WITH CAE AND ILM AND
HAVE OPTED TO CANCEL THE FLASH FLOOD WATCH.
TONIGHT...ISENTROPIC LIFT LOOKS TO RETURN ESPECIALLY OVER THE
WESTERN PIEDMONT AND AREAS OF RAIN AND DRIZZLE SHOULD SPREAD SLOWLY
WEST TO EAST. IN THE DRIER AIR...LOWER CHANCES OF RAIN IN THE
NORTHEAST WHERE THE RAP SHOWS A DEFINITE MINIMA OF 850MB THETA-E.
OVERNIGHT LOWS TONIGHT MID TO UPPER 60S.
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 315 AM SUNDAY...
THE MID LEVEL SHORT WAVE CURRENTLY OVER THE CENTRAL PLAINS WILL MOVE
SE TODAY AND TONIGHT...CROSSING THE TN VALLEY DURING THE DAY MONDAY.
AS THIS SHORT WAVE APPROACHES...MODELS ARE STILL SHOWING A SFC LOW
DEVELOPING ON THE BOUNDARY TO OUR SOUTH ON MONDAY AND LIFTING TO THE
NORTHEAST MONDAY NIGHT. GIVEN THE STRENGTH OF THE CAD...IT APPEARS
THAT MOST OF OUR CWA WILL REMAIN ON THE COOL SIDE OF THE BOUNDARY
WITH THE SFC WAVE STAYING TO OUR SOUTH...AND ANY ADDITIONAL RAINFALL
REMAINING ON THE LIGHT SIDE. BUT GIVEN THE RECENT MODEL
CHALLENGES...CONFIDENCE ISN`T PARTICULARLY HIGH AT THIS POINT. FOR
NOW WILL CONTINUE THE CLOUDY...DAMP...AND COOLER-THAN-NORMAL
FORECAST WITH FAIRLY HIGH POPS BUT LIGHT QPF. HIGHS ONCE AGAIN IN
THE 70S AND LOWS MONDAY NIGHT IN THE UPPER 60S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 315 AM SUNDAY...
TUESDAY... A SHORTWAVE WILL MOVE ACROSS THE MIDWEST ON TUESDAY WHILE
A SURFACE LOW LIFTS TOWARD THE GREAT LAKES. A SECONDARY LOW IS
EXPECTED TO BE MIGRATING ALONG THE STATIONARY/WEDGE FRONT OVER SC
EARLY TUESDAY. MODELS SHOW THE WEDGE FRONT RETREATING NORTHWARD
LATE MONDAY INTO TUESDAY AS A WEAK 850MB WARM FRONT LIFTS ACROSS THE
AREA. HOWEVER...EXPECT SOME OF THE CAD AIRMASS TO LINGER INTO
TUESDAY WITH WEAK FLOW BETWEEN THE AFOREMENTIONED SURFACE LOWS. A
COLD FRONT ATTENDANT TO THE PRIMARY LOW WILL APPROACH FROM THE WEST
ON TUESDAY AND MOVE INTO CENTRAL NC TUESDAY NIGHT. AHEAD OF THE
FRONT...MODELS SHOW WEST-SOUTHWESTERLY FLOW AND DRYING AT
700MB...WHICH SHOULD AID IN THE CAD EROSION. WHILE THE COLD FRONT
WILL LAG BACK TO THE WEST...WEAK HEIGHT FALLS ALOFT AND A
STRENGTHENING UPPER SPEED MAX AHEAD OF THE TROUGH AXIS COINCIDENT
WITH THE WARM SECTOR MAY LEAD TO SCATTERED SHOWERS AND
STORMS...MAINLY OVER EASTERN NC. THE EXTENT OF COVERAGE IS STILL
UNCERTAIN GIVEN THE UNCERTAINTY IN CLOUD COVER TUESDAY MORNING.
WILL SHOW A 40 POP OVER THE EASTERN CWA DURING THE
AFTERNOON...TRENDING DOWN TO JUST A SLIGHT CHANCE OVERNIGHT. HIGH
WILL DEPEND ON THE AMOUNT OF LINGERING STRATUS TUESDAY MORNING...AND
PREFER NAM/ECMWF BASED GUIDANCE OVER THE GFS WHICH LOOKS TOO
AGGRESSIVE WITH THE CAD EROSION. A GUIDANCE BLEND YIELDS 80-85
NORTHWEST TO SOUTHEAST. LOWS TUESDAY NIGHT IN THE UPPER 60S TO
LOWER 70S.
WEDNESDAY THROUGH SATURDAY... GUIDANCE HAS BEEN SUGGESTING THAT THE
COLD FRONT WILL LINGER OVER EASTERN NC ON WEDNESDAY BEFORE FINALLY
PUSHING EAST OF THE AREA THURSDAY AS HIGH PRESSURE MOVES FROM THE
MIDWEST TO THE MID-ATLANTIC STATES. ALOFT...A WEST-NORTHWEST
FLOW...ALBEIT STILL CYCLONIC AROUND A CLOSED LOW OVER EASTERN
CANADA...WILL SUPPORT A MOSTLY DRY FORECAST WITH PW DOWN TO AROUND
ONE INCH. HIGHS WILL BE IN THE LOW TO MID 80S...CREEPING BACK
TOWARD THE MID/UPPER 80S NEXT WEEKEND.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 200 PM SUNDAY...
AREAS OF IFR CONDITIONS CONTINUED EARLY IN THE AFTERNOON
PARTICULARLY OVER THE TRIAD AND THE SANDHILLS...WITH IMPROVEMENT
NOTED ELSEWHERE AND PARTICULARLY FROM THE TRIANGLE NORTH AND
NORTHEASDT WHERE THERE WERE MANY AREAS OF VFR CONDITIONS. THROUGH
THIS EVENING...AS DRIER AIR IN THE LOW LEVELS NUDGES IN FROM THE
NORTHEAST...SOME FURTHER IMPROVEMENT IN CEILINGS IS EXPECTED. IN THE
WEDGE OF HIGH PRESSURE...IT MAY BE MOST DIFFICULT FOR THE TRIAD TAFS
TO SHOW MUCH IMPROVEMENT BEYOND MAYBE MVFR...BUT IN MOST OTHER
LOCATIONS ANTICIPATE SOME IMPROVEMENT THROUGH MVFR TO VFR BEFORE A
RETURN TO LOWER CEILINGS OVERNIGHT...CONTINUING INTO MONDAY MORNING.
HIGHER CEILINGS SHOULD OCCUR IN THE DRIER AIR TOWARD KRWI...BUT EVEN
THERE SOME MVFR CONDITIONS ARE POSSIBLE LATE TONIGHT. AREAS OF LIGHT
RAIN AND DRIZZLE ARE EXPECTED ESPECIALLY ALONG AND WEST OF U.S. 1
TONIGHT WITH...AGAIN...HIGHER CHANCES TOWARD THE TRIAD.
BEYOND THE 18Z VALID TAF PERIOD...AREAS OF SUB-VFR CONDITIONS WILL
CONTINUE THROUGH TUESDAY MORNING. THE MOST LINGERING IFR CONDITIONS
SHOULD OCCUR TOWARD THE TRIAD. ON TUESDAY...SUB-VFR CEILINGS ARE
EXPECTED TO LIFT THROUGH MVFR TO VFR BY AFTERNOON...WITH ADVERSE
AVIATION CONDITIONS IN SCATTERED THUNDERSTORMS. PATCHY FOG IS
POSSIBLE TUESDAY NIGHT BEFORE CONDITIONS BECOME PREDOMINANTLY VFR
WEDNESDAY CONTINUING INTO THE END OF THE WORK WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...NP
LONG TERM...BLS
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
135 PM EDT SUN AUG 10 2014
.SYNOPSIS...
SOUPY AIR ACROSS THE REGION COMBINED WITH A MEANDERING FRONTAL
BOUNDARY AND ALREADY WET GROUND...WILL LEAD TO A POTENTIAL OF
LOCALIZED FLOODING THROUGH EARLY NEXT WEEK. A COLD FRONT WILL
CROSS THE COAST EARLY THURSDAY...FANNING IN DRIER AIR ACROSS
THE CAROLINAS LATE WEEK INTO NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM SUNDAY...NO CHANGES JUST YET...BUT AM DEBATING SOME.
THE FLOOD WATCH REMAINS IN PLACE FOR NOW BUT IT WOULD SEEM THAT
RAINFALL IS NOW GOING TO GRAVITATE TOWARDS SC ZONES DUE TO CLOSER
PROXIMITY TO THE FRONT. THIS BODES WELL FOR OUR FLOOD-WEARY NC ZONES
ESPECIALLY PENDER COUNTY. HOWEVER...DUE TO THE SEVERITY OF THE FLOOD
DAMAGE AND THE HEIGHTENED SENSITIVITY TO ANY ADDITIONAL WATER IN
SOME OF THOSE AREAS WILL WAIT A BIT LONGER AND MAKE DARN SURE THAT
THOSE AREAS ARE NOT GOING TO SEE ANY ADDITIONAL APPRECIABLE
RAINFALL. BUT AGAIN FOR NOW THE PRESENCE OF THE FRONT WELL TO OUR
SOUTH HAS INSTABILITY PARAMETERS MAXED OVER FAR SRN ZONES...WITH
MLCAPE IN THE 500-1000 RANGE...BUT RUC ALSO INDICATIVE THAT
ATMOSPHERE IS LARGELY CAPPED EVEN TO LAYER MIXING. SO ONCE AGAIN
WILL LEAVE FLOOD WATCH IN PLACE AREA-WIDE AS A PRECAUTION BUT NRN
ZONES WILL HAVE POPS LOWERED A BIT AND QPF EVEN MORESO.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 5 PM SUNDAY...HIGH PWAT AIR REMAINS ENTRENCHED OVER THE
AREA THROUGH MOST OF TUESDAY AND AN EXTENSION OF THE FLOOD WATCH
CANNOT BE RULED OUT SINCE LOCAL GROUNDS ARE SOGGY. THE PRESENCE OF
A PESKY FRONTAL BOUNDARY WILL RESULT IN ELEVATED POP VALUES BOTH
MONDAY AND TUESDAY COMPARED TO NORMAL SUMMER STANDARDS. OTHER THAN
THE THREAT OF FLOODING...NO OTHER SEVERE WEATHER PARAMETERS STAND
OUT AT THIS TIME FOR MONDAY AND TUESDAY. IN THIS PERIOD WE WILL
SEE A GRADUAL WARMING TREND WITH LOW 80S AND POSSIBLE MIDDLE 80S
TUESDAY WITH LOTS OF CLOUDS AND HUMIDITY STILL IN THE MIX. MINS
LIKELY TO REMAIN MOSTLY HELD IN THE 70S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 5 AM SATURDAY...A TRANSITION PERIOD AS WESTERLY FLOW AND
COLD FRONTAL PASSAGE BRINGS DRYING AND SLIGHTLY COOLER TEMPS FOR
AUGUST TO THE CAROLINAS. ANOTHER UPPER TROUGH WILL DIP INTO THE
EASTERN CONUS. AT THE SURFACE...IT APPEARS A WIND-SHIFT TO THE
NORTH N-NNE LOOKS TO OCCUR BY DAYBREAK THURSDAY OVER MOST OF THE
AREA AND PERHAPS CLEARING VERY NE SC AND THE WINYAH BAY REGION
SUNRISE THURSDAY. RAIN CHANCES GREATLY DIMINISH DUE TO THE DRYING
AND ESPECIALLY THE MID LEVELS. AUGUST HEATING MAY SPARK ISOLATED
SHALLOW CONVECTION BUT SLIGHT CHANCE DOES NOT SHOW UP IN THE DAY
4-7 EXTENDED PERIOD ZFP. MINIMUM TEMPERATURES LIKELY TO FALL IN
THE 60S THU/FRI NIGHT INLAND AND POSSIBLY INTO THE WEEKEND BEFORE
GRADUAL WARMING.
&&
.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
AS OF 18Z...IFR VSBYS/CIGS ARE OCCURRING AT KFLO/KLBT THIS AFTERNOON
WITH TEMPO SHOWERS AT KFLO. AT THE COASTAL TERMINALS IT WAS
VFR/TEMPO MVFR WITH SHOWERS INCREASING. MOST OF THE SHRA IS
LIGHT...EXCEPT THERE ARE ISOLATED SHOWERS WITH MDT-HVY RAINFALL. NO
LIGHTNING STRIKES ARE BEING DETECTED.
AT KLBT THERE IS MODERATE TO HIGH CONFIDENCE OF CIGS IMPROVING TO
MVFR THIS AFTERNOON. LATER THIS AFTERNOON THERE IS A GOOD CHANCE OF
VFR CIGS AT KLBT. AT KFLO CIGS/VSBYS COULD REMAIN IFR THROUGH MUCH
OF THE AFTERNOON WITH ONLY TEMPO IMPROVEMENT TO MVFR. AT THE COASTAL
TERMINALS TEMPO MVFR VSBYS IN SHOWERS CAN BE EXPECTED...BUT BRIEF
IFR VSBYS COULD OCCUR IN THE HEAVIER SHOWERS. SHOWERS SHOULD TEND TO
DISSIPATE NEAR KILM MID-LATE AFTERNOON WITH THE BEST POTENTIAL
SHIFTING TO THE KCRE/KMYR TERMINALS. SHRA/ISOLATED TSRA SHOULD
DISSIPATE SOUTHERN TERMINALS THIS EVENING.
OVERNIGHT EXPECT MAINLY MVFR VSBYS/CIGS AT THE COASTAL TERMINALS
WITH IFR VSBYS/TEMPO LIFR CIGS AT THE INLAND TERMINALS. MONDAY
MORNING THERE APPEARS TO BE A GOOD CHANCE OF MVFR CONDITIONS WITH
SHOWERS AT THE COASTAL TERMINALS.
EXTENDED OUTLOOK...ISOLATED TO SCATTERED SHRA/TSRA ALONG WITH TEMPO
MVFR CONDITIONS THROUGH TUESDAY AS A FRONT REMAINS STALLED IN THE
AREA. IMPROVING CONDITIONS WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM SUNDAY...NO CHANGES TO THE FORECAST. THE PREVIOUS
DISCUSSION FOLLOWS.
AS OF 640 AM SUNDAY...A BUMPY 3-4 FEET ON THE WATERS WITH 10-15
KT SE WINDS OUTSIDE OF TSTMS...AS A MODERATE E-ENE WIND FLOW
IMPACTS THE COASTAL WATERS. HEAVY RAIN MAY LIMIT VSBYS TO 1 NM AT
TIMES DUE TO TROPICAL AIR MASS TYPE RAINS. THE SEA SPECTRUM MOSTLY
A MDT E CHOP WITH DOMINANT WAVE ENERGY IN THE 4-5 SECONDS
RANGE...MIXED WITH WEAKER LONGER PERIOD SE WAVES. ISOLATED TSTMS
WILL PUSH LOCALLY HIGHER WINDS AND SEAS AND MARINERS SHOULD BE
MINDFUL OF RADAR TODAY AND TONIGHT. A SLOW STORM MOTION COULD
RESULT IN UNPREDICTABLE BLOSSOMING OF NEW STORM GROWTH.
SHORT TERM /MONDAY THROUGH TUESDAY/...
AS OF 5 AM SUNDAY...A STALLED FRONT BISECTING THE WATERS WILL
SUSTAIN ONSHORE WINDS OVER THE 0-20NM WATERS...AND UNSETTLED
MARINE WX TO BOOT. HEAVY RAIN POTENTIAL MAY LIMIT VSBYS AT TIMES.
GENERALLY 10-15 KT ONSHORE WINDS EXPECTED. TUESDAY LOW PRESSURE
LIFTS NORTH OVER THE WATERS ALLOWING SW WINDS TO DEVELOP TUESDAY
AFTN AND NIGHT OF 15 KT AHEAD OF AN APPROACHING COLD FRONT. NO
ADVISORY EXPECTED BUT A CAUTION STATEMENT CANNOT BE RULED OUT.
RESIDUAL E-ESE WAVES WILL PREVAIL MON/TUE...WITH A TRANSITION TO
MDT SW CHOP LATE INTO TUESDAY. MARINERS SHOULD OBTAIN A RADAR FIX
THIS PERIOD BEFORE DEPARTURE SINCE CONVECTION IS EXPECTED.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 5 AM SATURDAY...A TRANSITION PERIOD AS AN APPROACHING COLD
FRONT ON WEDNESDAY...CROSSES THE COAST EARLY ON THURSDAY BRINGING
A WIND SHIFT TO N AND NE INTO THURSDAY. A CAUTION STATEMENT MAY
BE NEEDED BUT ADVISORIES APPEAR UNLIKELY AT THIS TIME. TSTMS WILL
DECREASE DURING THIS PERIOD AS DRIER POST-FRONTAL AIR FILERS IN
OVER THE WATERS. THE NE FLOW WILL WEAKEN AND DIE WITH RETURN FLOW
QUICK ON THE HEELS INTO FRIDAY.
&&
.TIDES/COASTAL FLOODING...
AS OF 5 AM SUNDAY...HIGH ASTRONOMICAL TIDES WILL BRING HIGH SURF
RUN-UP ON AREA BEACHES WITH TONIGHTS HIGH TIDE IN THE MID EVENING.
WITH A SLIGHT LAG-TIME THIS WILL ALSO BRING FLOODING TO PORTIONS
OF THE LOWER CAPE FEAR RIVER INCLUDING THE DOWNTOWN WILMINGTON
AREA. FOR THIS REASON A COASTAL FLOOD ADVISORY HAS BEEN ISSUED.
TIDAL DECLINES OCCUR/PREDICTED MONDAY ONWARD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FLOOD WATCH THROUGH THIS EVENING FOR SCZ017-023-024-032-033-
039-053>056.
COASTAL FLOOD ADVISORY FROM 7 PM TO 10 PM EDT THIS EVENING FOR
SCZ054-056.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ087-096-099-105>110.
COASTAL FLOOD ADVISORY FROM 7 PM TO 10 PM EDT THIS EVENING FOR
NCZ106-108-110.
COASTAL FLOOD ADVISORY FROM 9 PM THIS EVENING TO MIDNIGHT EDT
TONIGHT FOR NCZ107.
MARINE...NONE.
&&
$$
NEAR TERM...MBB/MJC
SHORT TERM...8
LONG TERM...MJC
AVIATION...MRR
TIDES/COASTAL FLOODING...8
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1235 PM EDT SUN AUG 10 2014
.SYNOPSIS... A STATIONARY FRONT WILL REMAIN STALLED SOUTH OF NORTH
CAROLINA THROUGH EARLY NEXT WEEK...AS COOL HIGH PRESSURE NOSES IN
FROM THE NORTH. WAVES OF LOW PRESSURE TRACKING ALONG THE FRONT WILL
BRING CLOUDY AND DAMP WEATHER TO THE REGION THROUGH MONDAY.
&&
.NEAR TERM /THIS AFTERNOON AND TONIGHT/...
AS OF 1235 PM SUNDAY...
AREAS OF LIGHT RAIN AND DRIZZLE CONTINUED ACROSS PART OF CENTRAL
NORTH CAROLINA EARLY THIS AFTERNOON IN A MOIST AIR MASS ALONG AND
NEAR AN 850MB BOUNDARY NEAR THE SOUTH CAROLINA BORDER...NORTH OF THE
SURFACE FRONT WELL SOUTH THROUGH MUCH OF SOUTH CAROLINA. THE LATEST
SURFACE ANALYSIS SHOWED HIGH PRESSURE AT THE SURFACE NOSED IN
THROUGH THE AREA...WITH SOME CLEARING ON THE VISIBLE SATELLITE
IMAGERY OVER THE NORTHERN COASTAL PLAIN WHERE TEMPERATURES AT
KIXA...FOR EXAMPLE...HAD RISEN CLOSE TO 80 DEGREES. THE LATEST RAP
SOUNDINGS INDICATE THE CONTINUED EXPECTATION OF CONSIDERABLE CLOUDS
OVER MUCH OF CENTRAL NORTH CAROLINA...WITH ENOUGH CLEARING NORTHEAST
THAT TEMPERATURES SHOULD RISE TO HIGHS IN THE LOWER 80S.
FLASH FLOOD GUIDANCE IS TWO INCHES OR GREATER OVER THREE HOURS...AND
THE DEVELOPMENT OF ANY HEAVY RAIN SEEMS TO MORE LIKELY LIE OVER
SOUTH CAROLINA...POSSIBLY WITH SOME POCKETS OF HEAVY SHOWERS NEAR
THE SOUTH CAROLINA BORDER IF THE HRRR WRF VERIFIES. HOWEVER...IN
SOME OF THOSE LOCATIONS THE RAIN ON SATURDAY WAS LIGHT COMPARED TO
OTHERS IN CENTRAL NORTH CAROLINA. COORDINATED WITH CAE AND ILM AND
HAVE OPTED TO CANCEL THE FLASH FLOOD WATCH.
TONIGHT...ISENTROPIC LIFT LOOKS TO RETURN ESPECIALLY OVER THE
WESTERN PIEDMONT AND AREAS OF RAIN AND DRIZZLE SHOULD SPREAD SLOWLY
WEST TO EAST. IN THE DRIER AIR...LOWER CHANCES OF RAIN IN THE
NORTHEAST WHERE THE RAP SHOWS A DEFINITE MINIMA OF 850MB THETA-E.
OVERNIGHT LOWS TONIGHT MID TO UPPER 60S.
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 315 AM SUNDAY...
THE MID LEVEL SHORT WAVE CURRENTLY OVER THE CENTRAL PLAINS WILL MOVE
SE TODAY AND TONIGHT...CROSSING THE TN VALLEY DURING THE DAY MONDAY.
AS THIS SHORT WAVE APPROACHES...MODELS ARE STILL SHOWING A SFC LOW
DEVELOPING ON THE BOUNDARY TO OUR SOUTH ON MONDAY AND LIFTING TO THE
NORTHEAST MONDAY NIGHT. GIVEN THE STRENGTH OF THE CAD...IT APPEARS
THAT MOST OF OUR CWA WILL REMAIN ON THE COOL SIDE OF THE BOUNDARY
WITH THE SFC WAVE STAYING TO OUR SOUTH...AND ANY ADDITIONAL RAINFALL
REMAINING ON THE LIGHT SIDE. BUT GIVEN THE RECENT MODEL
CHALLENGES...CONFIDENCE ISN`T PARTICULARLY HIGH AT THIS POINT. FOR
NOW WILL CONTINUE THE CLOUDY...DAMP...AND COOLER-THAN-NORMAL
FORECAST WITH FAIRLY HIGH POPS BUT LIGHT QPF. HIGHS ONCE AGAIN IN
THE 70S AND LOWS MONDAY NIGHT IN THE UPPER 60S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 315 AM SUNDAY...
TUESDAY... A SHORTWAVE WILL MOVE ACROSS THE MIDWEST ON TUESDAY WHILE
A SURFACE LOW LIFTS TOWARD THE GREAT LAKES. A SECONDARY LOW IS
EXPECTED TO BE MIGRATING ALONG THE STATIONARY/WEDGE FRONT OVER SC
EARLY TUESDAY. MODELS SHOW THE WEDGE FRONT RETREATING NORTHWARD
LATE MONDAY INTO TUESDAY AS A WEAK 850MB WARM FRONT LIFTS ACROSS THE
AREA. HOWEVER...EXPECT SOME OF THE CAD AIRMASS TO LINGER INTO
TUESDAY WITH WEAK FLOW BETWEEN THE AFOREMENTIONED SURFACE LOWS. A
COLD FRONT ATTENDANT TO THE PRIMARY LOW WILL APPROACH FROM THE WEST
ON TUESDAY AND MOVE INTO CENTRAL NC TUESDAY NIGHT. AHEAD OF THE
FRONT...MODELS SHOW WEST-SOUTHWESTERLY FLOW AND DRYING AT
700MB...WHICH SHOULD AID IN THE CAD EROSION. WHILE THE COLD FRONT
WILL LAG BACK TO THE WEST...WEAK HEIGHT FALLS ALOFT AND A
STRENGTHENING UPPER SPEED MAX AHEAD OF THE TROUGH AXIS COINCIDENT
WITH THE WARM SECTOR MAY LEAD TO SCATTERED SHOWERS AND
STORMS...MAINLY OVER EASTERN NC. THE EXTENT OF COVERAGE IS STILL
UNCERTAIN GIVEN THE UNCERTAINTY IN CLOUD COVER TUESDAY MORNING.
WILL SHOW A 40 POP OVER THE EASTERN CWA DURING THE
AFTERNOON...TRENDING DOWN TO JUST A SLIGHT CHANCE OVERNIGHT. HIGH
WILL DEPEND ON THE AMOUNT OF LINGERING STRATUS TUESDAY MORNING...AND
PREFER NAM/ECMWF BASED GUIDANCE OVER THE GFS WHICH LOOKS TOO
AGGRESSIVE WITH THE CAD EROSION. A GUIDANCE BLEND YIELDS 80-85
NORTHWEST TO SOUTHEAST. LOWS TUESDAY NIGHT IN THE UPPER 60S TO
LOWER 70S.
WEDNESDAY THROUGH SATURDAY... GUIDANCE HAS BEEN SUGGESTING THAT THE
COLD FRONT WILL LINGER OVER EASTERN NC ON WEDNESDAY BEFORE FINALLY
PUSHING EAST OF THE AREA THURSDAY AS HIGH PRESSURE MOVES FROM THE
MIDWEST TO THE MID-ATLANTIC STATES. ALOFT...A WEST-NORTHWEST
FLOW...ALBEIT STILL CYCLONIC AROUND A CLOSED LOW OVER EASTERN
CANADA...WILL SUPPORT A MOSTLY DRY FORECAST WITH PW DOWN TO AROUND
ONE INCH. HIGHS WILL BE IN THE LOW TO MID 80S...CREEPING BACK
TOWARD THE MID/UPPER 80S NEXT WEEKEND.
&&
.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
AS OF 1235 PM SUNDAY...
AREAS OF IFR CONDITIONS CONTINUED DURING THE NOON HOUR WITH SOME
DEFINITE IMPROVEMENT TO VFR FROM THE TRIANGLE NORTH AND NORTHEAST IN
PARTICULAR. AREAS OF RAIN AND DRIZZLE CONTINUED ALONG WEST OF A LINE
FROM ABOUT KGSB TO KGSO. TONIGHT AFTER 03Z-06Z...LOW CLOUDS AND IFR
OR LIFR CONDITIONS WILL QUICKLY RETURN ACROSS MOST OF CENTRAL NC...
ESPECIALLY OVER THE WESTERN PIEDMONT. WINDS DURING THE 24 HOUR TAF
PERIOD WILL REMAIN E-ENE WIND BELOW 10KT.
BEYOND THE 24 HOUR TAF PERIOD...SUB-VFR CONDITIONS WILL PERSIST
UNTIL A COLD FRONT MOVES THROUGH THE AREA ON TUESDAY. DRY AIR IN THE
WAKE OF THIS FRONT WILL MEAN A RETURN TO VFR CONDITIONS FOR THE
MIDDLE AND LATTER HALF OF THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...DJF
SHORT TERM...NP
LONG TERM...BLS
AVIATION...NP/DJF
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1045 AM EDT SUN AUG 10 2014
.SYNOPSIS...
SOUPY AIR ACROSS THE REGION COMBINED WITH A MEANDERING FRONTAL
BOUNDARY AND ALREADY WET GROUND...WILL LEAD TO A POTENTIAL OF
LOCALIZED FLOODING THROUGH EARLY NEXT WEEK. A COLD FRONT WILL
CROSS THE COAST EARLY THURSDAY...FANNING IN DRIER AIR ACROSS
THE CAROLINAS LATE WEEK INTO NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM SUNDAY...NO CHANGES JUST YET...BUT AM DEBATING SOME.
THE FLOOD WATCH REMAINS IN PLACE FOR NOW BUT IT WOULD SEEM THAT
RAINFALL IS NOW GOING TO GRAVITATE TOWARDS SC ZONES DUE TO CLOSER
PROXIMITY TO THE FRONT. THIS BODES WELL FOR OUR FLOOD-WEARY NC ZONES
ESPECIALLY PENDER COUNTY. HOWEVER...DUE TO THE SEVERITY OF THE FLOOD
DAMAGE AND THE HEIGHTENED SENSITIVITY TO ANY ADDITIONAL WATER IN
SOME OF THOSE AREAS WILL WAIT A BIT LONGER AND MAKE DARN SURE THAT
THOSE AREAS ARE NOT GOING TO SEE ANY ADDITIONAL APPRECIABLE
RAINFALL. BUT AGAIN FOR NOW THE PRESENCE OF THE FRONT WELL TO OUR
SOUTH HAS INSTABILITY PARAMETERS MAXED OVER FAR SRN ZONES...WITH
MLCAPE IN THE 500-1000 RANGE...BUT RUC ALSO INDICATIVE THAT
ATMOSPHERE IS LARGELY CAPPED EVEN TO LAYER MIXING. SO ONCE AGAIN
WILL LEAVE FLOOD WATCH IN PLACE AREA-WIDE AS A PRECAUTION BUT NRN
ZONES WILL HAVE POPS LOWERED A BIT AND QPF EVEN MORESO.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 5 PM SUNDAY...HIGH PWAT AIR REMAINS ENTRENCHED OVER THE
AREA THROUGH MOST OF TUESDAY AND AN EXTENSION OF THE FLOOD WATCH
CANNOT BE RULED OUT SINCE LOCAL GROUNDS ARE SOGGY. THE PRESENCE OF
A PESKY FRONTAL BOUNDARY WILL RESULT IN ELEVATED POP VALUES BOTH
MONDAY AND TUESDAY COMPARED TO NORMAL SUMMER STANDARDS. OTHER THAN
THE THREAT OF FLOODING...NO OTHER SEVERE WEATHER PARAMETERS STAND
OUT AT THIS TIME FOR MONDAY AND TUESDAY. IN THIS PERIOD WE WILL
SEE A GRADUAL WARMING TREND WITH LOW 80S AND POSSIBLE MIDDLE 80S
TUESDAY WITH LOTS OF CLOUDS AND HUMIDITY STILL IN THE MIX. MINS
LIKELY TO REMAIN MOSTLY HELD IN THE 70S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 5 AM SATURDAY...A TRANSITION PERIOD AS WESTERLY FLOW AND
COLD FRONTAL PASSAGE BRINGS DRYING AND SLIGHTLY COOLER TEMPS FOR
AUGUST TO THE CAROLINAS. ANOTHER UPPER TROUGH WILL DIP INTO THE
EASTERN CONUS. AT THE SURFACE...IT APPEARS A WIND-SHIFT TO THE
NORTH N-NNE LOOKS TO OCCUR BY DAYBREAK THURSDAY OVER MOST OF THE
AREA AND PERHAPS CLEARING VERY NE SC AND THE WINYAH BAY REGION
SUNRISE THURSDAY. RAIN CHANCES GREATLY DIMINISH DUE TO THE DRYING
AND ESPECIALLY THE MID LEVELS. AUGUST HEATING MAY SPARK ISOLATED
SHALLOW CONVECTION BUT SLIGHT CHANCE DOES NOT SHOW UP IN THE DAY
4-7 EXTENDED PERIOD ZFP. MINIMUM TEMPERATURES LIKELY TO FALL IN
THE 60S THU/FRI NIGHT INLAND AND POSSIBLY INTO THE WEEKEND BEFORE
GRADUAL WARMING.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 12Z...IFR/LIFR AT KFLO/KLBT THIS MORNING. AT KILM ITS VFR
WHILE AT KCRE/KMYR TEMPO IFR/LIFR CIGS ARE OCCURRING. MOST OF THE
SHRA ARE OCCURRING NE OF KLBT TO NEAR KILM. OTHER SHOWERS ARE S-SE
OF KMYR. MOST OF THE SHRA IS LIGHT...EXCEPT MDT-HVY RAINFALL IS
OCCURRING JUST SE OF KILM. NO LIGHTNING STRIKES ARE BEING
DETECTED.
THROUGH MID-MORNING EXPECT FLIGHT CONDITIONS AT KFLO/KLBT TO SLOWLY
IMPROVE TO IFR. IFR CIGS COULD PERSIST UNTIL 18Z WITH HIGHEST
CONFIDENCE OF THIS AT KFLO. AT KLBT THERE IS MODERATE TO HIGH
CONFIDENCE OF CIGS IMPROVING TO MVFR. IN THE AFTERNOON THERE IS A
GOOD CHANCE OF VFR CIGS AT KLBT BUT KFLO COULD REMAIN IFR/MVFR.
THROUGH MID MORNING THERE IS A SLIGHT CHANCE THAT MVFR/TEMPO IFR
VSBYS COULD OCCUR IN SHOWERS NEAR KILM. THROUGH MID MORNING IFR/LIFR
CIGS SHOULD LIFT TO VFR/TEMPO MVFR AT KCRE/KMYR. SHOWERS SHOULD TEND
TO DISSIPATE NEAR KILM MID-LATE MORNING WITH THE BEST POTENTIAL
SHIFTING TO THE KCRE/KMYR/KFLO TERMINALS FOR LATE MORNING/ AFTERNOON
HOURS. SHRA/ISOLATED TSRA SHOULD DISSIPATE SOUTHERN TERMINALS BY
LATE AFTERNOON.
EXTENDED OUTLOOK...ISOLATED TO SCATTERED SHRA/TSRA ALONG WITH TEMPO
MVFR CONDITIONS THROUGH TUESDAY AS A FRONT REMAINS STALLED IN THE
AREA. IMPROVING CONDITIONS WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM SUNDAY...NO CHANGES TO THE FORECAST. THE PREVIOUS
DISCUSSION FOLLOWS.
AS OF 640 AM SUNDAY...A BUMPY 3-4 FEET ON THE WATERS WITH 10-15
KT SE WINDS OUTSIDE OF TSTMS...AS A MODERATE E-ENE WIND FLOW
IMPACTS THE COASTAL WATERS. HEAVY RAIN MAY LIMIT VSBYS TO 1 NM AT
TIMES DUE TO TROPICAL AIR MASS TYPE RAINS. THE SEA SPECTRUM MOSTLY
A MDT E CHOP WITH DOMINANT WAVE ENERGY IN THE 4-5 SECONDS
RANGE...MIXED WITH WEAKER LONGER PERIOD SE WAVES. ISOLATED TSTMS
WILL PUSH LOCALLY HIGHER WINDS AND SEAS AND MARINERS SHOULD BE
MINDFUL OF RADAR TODAY AND TONIGHT. A SLOW STORM MOTION COULD
RESULT IN UNPREDICTABLE BLOSSOMING OF NEW STORM GROWTH.
SHORT TERM /MONDAY THROUGH TUESDAY/...
AS OF 5 AM SUNDAY...A STALLED FRONT BISECTING THE WATERS WILL
SUSTAIN ONSHORE WINDS OVER THE 0-20NM WATERS...AND UNSETTLED
MARINE WX TO BOOT. HEAVY RAIN POTENTIAL MAY LIMIT VSBYS AT TIMES.
GENERALLY 10-15 KT ONSHORE WINDS EXPECTED. TUESDAY LOW PRESSURE
LIFTS NORTH OVER THE WATERS ALLOWING SW WINDS TO DEVELOP TUESDAY
AFTN AND NIGHT OF 15 KT AHEAD OF AN APPROACHING COLD FRONT. NO
ADVISORY EXPECTED BUT A CAUTION STATEMENT CANNOT BE RULED OUT.
RESIDUAL E-ESE WAVES WILL PREVAIL MON/TUE...WITH A TRANSITION TO
MDT SW CHOP LATE INTO TUESDAY. MARINERS SHOULD OBTAIN A RADAR FIX
THIS PERIOD BEFORE DEPARTURE SINCE CONVECTION IS EXPECTED.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 5 AM SATURDAY...A TRANSITION PERIOD AS AN APPROACHING COLD
FRONT ON WEDNESDAY...CROSSES THE COAST EARLY ON THURSDAY BRINGING
A WIND SHIFT TO N AND NE INTO THURSDAY. A CAUTION STATEMENT MAY
BE NEEDED BUT ADVISORIES APPEAR UNLIKELY AT THIS TIME. TSTMS WILL
DECREASE DURING THIS PERIOD AS DRIER POST-FRONTAL AIR FILERS IN
OVER THE WATERS. THE NE FLOW WILL WEAKEN AND DIE WITH RETURN FLOW
QUICK ON THE HEELS INTO FRIDAY.
&&
.TIDES/COASTAL FLOODING...
AS OF 5 AM SUNDAY...HIGH ASTRONOMICAL TIDES WILL BRING HIGH SURF
RUN-UP ON AREA BEACHES WITH TONIGHTS HIGH TIDE IN THE MID EVENING.
WITH A SLIGHT LAG-TIME THIS WILL ALSO BRING FLOODING TO PORTIONS
OF THE LOWER CAPE FEAR RIVER INCLUDING THE DOWNTOWN WILMINGTON
AREA. FOR THIS REASON A COASTAL FLOOD ADVISORY HAS BEEN ISSUED.
TIDAL DECLINES OCCUR/PREDICTED MONDAY ONWARD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FLOOD WATCH THROUGH THIS EVENING FOR SCZ017-023-024-032-033-
039-053>056.
COASTAL FLOOD ADVISORY FROM 7 PM TO 10 PM EDT THIS EVENING FOR
SCZ054-056.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ087-096-099-105>110.
COASTAL FLOOD ADVISORY FROM 7 PM TO 10 PM EDT THIS EVENING FOR
NCZ106-108-110.
COASTAL FLOOD ADVISORY FROM 9 PM THIS EVENING TO MIDNIGHT EDT
TONIGHT FOR NCZ107.
MARINE...NONE.
&&
$$
NEAR TERM...MBB/MJC
SHORT TERM...8
LONG TERM...MJC
AVIATION...MRR
TIDES/COASTAL FLOODING...8
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1025 AM EDT SUN AUG 10 2014
.SYNOPSIS... A STATIONARY FRONT WILL REMAIN STALLED SOUTH OF NORTH
CAROLINA THROUGH EARLY NEXT WEEK...AS COOL HIGH PRESSURE NOSES IN
FROM THE NORTH. WAVES OF LOW PRESSURE TRACKING ALONG THE FRONT WILL
BRING CLOUDY AND DAMP WEATHER TO THE REGION THROUGH MONDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1025 AM SUNDAY...
AREAS OF LIGHT RAIN AND DRIZZLE CONTINUED ACROSS PART OF CENTRAL
NORTH CAROLINA THIS MORNING IN A MOIST AIR MASS ALONG AND NEAR AN
850MB BOUNDARY NEAR THE SOUTH CAROLINA BORDER...NORTH OF THE SURFACE
FRONT WELL SOUTH THROUGH MUCH OF SOUTH CAROLINA. THE LATEST SURFACE
ANALYSIS SHOWED HIGH PRESSURE AT THE SURFACE NOSED IN THROUGH THE
AREA...WITH SOME CLEARING ON THE VISIBLE SATELLITE IMAGERY OVER THE
NORTHERN COASTAL PLAIN. THE LATEST RAP SOUNDINGS INDICATE THE
CONTINUED EXPECTATION OF CONSIDERABLE CLOUDS OVER MUCH OF CENTRAL
NORTH CAROLINA...POSSIBLY WITH SOME DRYING PARTICULARLY NORTHEAST OF
THE TRIANGLE. ON THE OTHER HAND...THESE SAME SOUNDINGS SHOW DEEP
MOISTURE TO NOT BE HIGHLY PLENTIFUL. THE RESULT COULD BE AREAS OF
MOSTLY LIGHT RAIN AND DRIZZLE.
THE ONLY CONCERN IS A SHORTWAVE MOVING SOUTHEAST IN THE NORTHWEST
FLOW ALOFT FORECAST BY THE RAP TO MOVE THROUGH CENTRAL NORTH
CAROLINA LATER TODAY...WHICH MAY RESULT IN MORE WIDESPREAD AND
CONTINUOUS RAIN ESPECIALLY IN VICINITY OF THE 850MB FRONT. THE
LATEST HRRR WRF WOULD SUGGEST THIS PRECIPITATION WOULD BE MOST
WIDESPREAD RIGHT ALONG THE SOUTH CAROLINA BORDER THIS AFTERNOON...
AND THE LATEST IR SATELLITE IMAGES DO SHOW SOME COOLING OF THE CLOUD
TOPS IN THAT AREA. GIVEN SOME OF THE REPORTS OF RAIN...ESPECIALLY
FROM COCORAHS OBSERVERS...NOTED AROUND 4 INCHES IN PARTS OF WESTERN
CUMBERLAND COUNTY...FOR EXAMPLE...HAVE OPTED TO CONTINUE THE FLASH
FLOOD WATCH FOR THE SANDHILLS AND SOUTHERN COASTAL PLAIN. ON THE
OTHER HAND...WITH THE EXPECTATION OF LIGHTER RAIN FARTHER NORTH AND
SOMEWHAT OF A LULL OVERALL FOR A WHILE...OPTED TO DISCONTINUE THE
FLASH FLOOD WATCH FOR CHATHAM...WAKE...AND WILSON COUNTIES. WILL
REVIEW THE ONGOING TRENDS FOR POSSIBLE FURTHER TRIMMING LATE THIS
MORNING AND EARLY THIS AFTERNOON.
LITTLE CHANGE IN THE PATTERN TONIGHT...AND FORECAST CROSS SECTIONS
SHOW SOME SHALLOW DRY AIR RETREATING NORTHWARD. CLOUDY CONDITIONS
SHOULD CONTINUE...ALONG WITH PATCHES OF LIGHT RAIN OR DRIZZLE.
TEMPS FALLING BACK A FEW DEGREES TO THE MID-UPR 60S FOR LOWS.
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 315 AM SUNDAY...
THE MID LEVEL SHORT WAVE CURRENTLY OVER THE CENTRAL PLAINS WILL MOVE
SE TODAY AND TONIGHT...CROSSING THE TN VALLEY DURING THE DAY MONDAY.
AS THIS SHORT WAVE APPROACHES...MODELS ARE STILL SHOWING A SFC LOW
DEVELOPING ON THE BOUNDARY TO OUR SOUTH ON MONDAY AND LIFTING TO THE
NORTHEAST MONDAY NIGHT. GIVEN THE STRENGTH OF THE CAD...IT APPEARS
THAT MOST OF OUR CWA WILL REMAIN ON THE COOL SIDE OF THE BOUNDARY
WITH THE SFC WAVE STAYING TO OUR SOUTH...AND ANY ADDITIONAL RAINFALL
REMAINING ON THE LIGHT SIDE. BUT GIVEN THE RECENT MODEL
CHALLENGES...CONFIDENCE ISN`T PARTICULARLY HIGH AT THIS POINT. FOR
NOW WILL CONTINUE THE CLOUDY...DAMP...AND COOLER-THAN-NORMAL
FORECAST WITH FAIRLY HIGH POPS BUT LIGHT QPF. HIGHS ONCE AGAIN IN
THE 70S AND LOWS MONDAY NIGHT IN THE UPPER 60S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 315 AM SUNDAY...
TUESDAY... A SHORTWAVE WILL MOVE ACROSS THE MIDWEST ON TUESDAY WHILE
A SURFACE LOW LIFTS TOWARD THE GREAT LAKES. A SECONDARY LOW IS
EXPECTED TO BE MIGRATING ALONG THE STATIONARY/WEDGE FRONT OVER SC
EARLY TUESDAY. MODELS SHOW THE WEDGE FRONT RETREATING NORTHWARD
LATE MONDAY INTO TUESDAY AS A WEAK 850MB WARM FRONT LIFTS ACROSS THE
AREA. HOWEVER...EXPECT SOME OF THE CAD AIRMASS TO LINGER INTO
TUESDAY WITH WEAK FLOW BETWEEN THE AFOREMENTIONED SURFACE LOWS. A
COLD FRONT ATTENDANT TO THE PRIMARY LOW WILL APPROACH FROM THE WEST
ON TUESDAY AND MOVE INTO CENTRAL NC TUESDAY NIGHT. AHEAD OF THE
FRONT...MODELS SHOW WEST-SOUTHWESTERLY FLOW AND DRYING AT
700MB...WHICH SHOULD AID IN THE CAD EROSION. WHILE THE COLD FRONT
WILL LAG BACK TO THE WEST...WEAK HEIGHT FALLS ALOFT AND A
STRENGTHENING UPPER SPEED MAX AHEAD OF THE TROUGH AXIS COINCIDENT
WITH THE WARM SECTOR MAY LEAD TO SCATTERED SHOWERS AND
STORMS...MAINLY OVER EASTERN NC. THE EXTENT OF COVERAGE IS STILL
UNCERTAIN GIVEN THE UNCERTAINTY IN CLOUD COVER TUESDAY MORNING.
WILL SHOW A 40 POP OVER THE EASTERN CWA DURING THE
AFTERNOON...TRENDING DOWN TO JUST A SLIGHT CHANCE OVERNIGHT. HIGH
WILL DEPEND ON THE AMOUNT OF LINGERING STRATUS TUESDAY MORNING...AND
PREFER NAM/ECMWF BASED GUIDANCE OVER THE GFS WHICH LOOKS TOO
AGGRESSIVE WITH THE CAD EROSION. A GUIDANCE BLEND YIELDS 80-85
NORTHWEST TO SOUTHEAST. LOWS TUESDAY NIGHT IN THE UPPER 60S TO
LOWER 70S.
WEDNESDAY THROUGH SATURDAY... GUIDANCE HAS BEEN SUGGESTING THAT THE
COLD FRONT WILL LINGER OVER EASTERN NC ON WEDNESDAY BEFORE FINALLY
PUSHING EAST OF THE AREA THURSDAY AS HIGH PRESSURE MOVES FROM THE
MIDWEST TO THE MID-ATLANTIC STATES. ALOFT...A WEST-NORTHWEST
FLOW...ALBEIT STILL CYCLONIC AROUND A CLOSED LOW OVER EASTERN
CANADA...WILL SUPPORT A MOSTLY DRY FORECAST WITH PW DOWN TO AROUND
ONE INCH. HIGHS WILL BE IN THE LOW TO MID 80S...CREEPING BACK
TOWARD THE MID/UPPER 80S NEXT WEEKEND.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 635 AM SUNDAY...
LIFR AND IFR CONDITIONS WITH LOW CLOUDS...FOG...AND PATCHY LIGHT
RAIN OR DRIZZLE ARE ONGOING ATTM ACROSS MUCH OF CENTRAL NC. WHILE
THIS IS EXPECTED TO CONTINUE THROUGH MOST OF THE MORNING...MODELS
CONTINUE TO SUGGEST THAT DRIER AIR NOT FAR ABOVE THE SURFACE WILL
MOVE SOUTH FROM VIRGINIA AND MAY HELP IMPROVE CIGS TO 1500FT AGL OR
HIGHER LATER THIS AFTERNOON. THE LOCATIONS WITH THE BEST CHANCE FOR
THIS HAPPENING STILL APPEARS TO BE FROM KRDU NORTH AND EASTWARD.
SINCE THE NEAR-SFC LAYER WILL REMAIN NEARLY SATURATED...TONIGHT
AFTER 03Z-06Z...LOW CLOUDS AND IFR OR LIFR CONDITIONS WILL QUICKLY
RETURN ACROSS MOST OF CENTRAL NC. WINDS DURING THE 24 HOUR TAF
PERIOD WILL REMAIN E-ENE WIND BELOW 10KT.
BEYOND THE 24 HOUR TAF PERIOD...SUB-VFR CONDITIONS WILL PERSIST
UNTIL A COLD FRONT MOVES THROUGH THE AREA ON TUESDAY. DRY AIR IN THE
WAKE OF THIS FRONT WILL MEAN A RETURN TO VFR CONDITIONS FOR THE
MIDDLE AND LATTER HALF OF THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH UNTIL 8 PM EDT
THIS EVENING FOR NCZ042-073>078-083>086-088-089.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...DJF/NP
SHORT TERM...NP
LONG TERM...BLS
AVIATION...NP
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
747 AM EDT SUN AUG 10 2014
.SYNOPSIS...
A STATIONARY FRONT WILL REMAIN STALLED JUST TO THE SOUTH THROUGH
MONDAY WITH WEAK AREAS OF LOW PRESSURE MOVING EAST ALONG IT. THE
FRONT WILL LIFT NORTH AND GRADUALLY DISSIPATE ON TUESDAY. A COLD
FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY NIGHT AND CROSS THE
REGION LATE WEDNESDAY AND WEDNESDAY NIGHT. HIGH PRESSURE WILL
BUILD IN BEHIND THE FRONT LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 730 AM SUN...UPDATED POPS THIS MORNING AS GREATER COVERAGE
OF PRECIP OCCURING OVER THE COASTAL PLAIN. MODELS NOT CAPTURING
PRECIP TOO WELL THIS MORNING. FOLLOWED HRRR FOR PRECIP TRENDS THIS
MORNING.
THE UPPER LEVEL PATTERN ACROSS EASTERN NC CONSISTS OF WNW FLOW
JUST SOUTH OF UPPER RIDGING THAT WILL MOVE INTO THE MID-ATLANTIC
STATES AS AN UPPER TROUGH DIGS FROM THE CANADIAN PLAINS INTO THE
GREAT LAKES TODAY AND TONIGHT. AT THE SURFACE A STATIONARY FRONT
REMAINS STALLED SOUTH OF THE AREA...GENERALLY AN EAST-WEST LINE
ACROSS SOUTH CAROLINA...WITH HIGH PRES RIDGING IN FROM THE NORTH.
MODELS TRENDING DRIER ACROSS THE REGION TODAY LIKELY DUE TO
SEVERAL FACTORS INCLUDING A WEAKENING UPPER LEVEL JET STREAK
THAT GRADUALLY SHIFTS SOUTH BRINGING DIMINISHED UPPER LEVEL
DIFFLUENCE WHICH IS ALSO SHIFTED SOUTH OF THE REGION...WEAKENING
ISENTROPIC LIFT WITH THE NAM EVEN SHOWING WEAK ISENTROPIC
DOWN-GLIDE...AND DRIER AIR FILTERING IN FROM THE NORTH WITH MODELS
INDICATING PWATS DROPPING AS LOW AS 1 TO 1.5" ACROSS THE NORTHEAST
HALF OF THE CWA (HOWEVER REMAIN AROUND 1.5-2" SOUTHWEST SECTIONS).
SO WILL HAVE A WIDE RANGE OF POPS ACROSS THE REGION FROM SLIGHT
CHANCE NORTHEAST SECTIONS TO LIKELY FAR SOUTHWEST CLOSER TO THE
STATIONARY BOUNDARY AND AREA OF LOW PRES THAT IS PROGGED TO MOVE
TO SOUTHEAST OF CAPE FEAR LATER TODAY. WITH LIMITED INSTABILITY
AND LITTLE SURFACE BASED HEATING DUE TO EXTENSIVE CLOUD COVER
THINK THUNDERSTORM CHANCES WILL BE MINIMAL WITH BETTER CHANCES FAR
SOUTHERN SECTIONS AND ACROSS THE WATERS SOUTH OF CAPE HATTERAS.
BASIN AVERAGE QPF AMOUNTS DO NOT LOOK TOO EXCESSIVE BUT SOME
AREAS COULD EXPERIENCE LOCALLY HIGH RAINFALL AMOUNTS DUE TO THE
SLOW STORM MOTION...MAINLY ACROSS SOUTHERN AREAS WHERE PWATS ARE
HIGHER. EASTERLY FLOW AND CLOUDS WILL HOLD TEMPS WELL BELOW
AVERAGE AGAIN TODAY WITH HIGHS IN THE UPPER 70S TO LOWER 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
AS OF 330 AM SUN...THE PATTERN REMAINS RELATIVELY UNCHANGED
THROUGH THE EVENING HOURS WITH HIGHER RAIN CHANCES ACROSS SOUTHERN
SECTIONS CLOSER TO THE STALLED FRONT AND WEAK AREA OF LOW PRES.
WILL SEE DEEPER MOISTURE BEGIN TO SLOWLY LIFT NORTHEASTWARD AFTER
MIDNIGHT AS THE UPPER TROUGH PUSHES INTO THE MID WEST WITH
ISENTROPIC LIFT INCREASING LATE. LOWS EXPECTED IN THE UPPER 60S
INLAND TO MID 70S ALONG THE COAST.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 330 AM SUNDAY...LOW PRESSURE WILL MOVE ALONG STALLED FRONTAL
BOUNDARY JUST TO THE SOUTH AND EAST OF THE MHX CWA MONDAY AND
MONDAY NIGHT WITH THE LOW LIFTING NORTH OF THE AREA BY TUESDAY.
BEST MOISTURE TRANSPORT/LIFT MOVES FROM SOUTH TO NORTH ACROSS THE
AREA MONDAY INTO MONDAY NIGHT AND HAVE LIKELY POPS OVER THE
SOUTHERN HALF OF THE CWA MONDAY WITH THE LIKELY POPS TRANSITIONING
NORTH BY MONDAY NIGHT. A COLD FRONT WILL MOVE INTO THE WESTERN
PART OF THE STATE TUESDAY AFTERNOON AND MOVE OFFSHORE EARLY
WEDNESDAY. DEEP MOISTURE AND CONVERGENCE AHEAD OF THE FRONT WILL
LEAD TO A HIGH CHANCE POPS FOR SHOWERS AND A FEW TSTMS TUESDAY
AFTERNOON AND EVENING. HAVE KEPT SMALL POPS IN FOR WEDNESDAY GIVEN
SOME UNCERTAINTY ON HOW QUICKLY THE COLD FRONT WILL CLEAR THE
AREA. THURSDAY AND FRIDAY CONTINUE TO LOOK DRY WITH HIGH PRESSURE
BUILDING SOUTH FROM THE GREAT LAKES. OVERNIGHT LOWS WILL ALSO BE A
BIT COOLER...MAINLY INLAND...WITH LOWS INTO THE MID 60S. HOWEVER
WITH MORE SUNSHINE...DAYTIME HIGHS WILL EDGE BACK TOWARD NORMAL
LEVELS FOR AUGUST...UPPER 80S TO AROUND 90. A CHANCE OF SEA BREEZE
TSTMS RETURNS BY SATURDAY AFTERNOON WITH INCREASED MOISTURE FROM
THE SOUTHWEST.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH SUNDAY NIGHT/...
AS OF 730 AM SUN...AREAS OF SHOWERS HAVE INCREASED IN COVERAGE
ACROSS THE COASTAL PLAIN THIS MORNING ALLOWING CIGS TO DROP
MVFR/IFR AT OAJ AND ISO FOR THE PAST COUPLE HOURS. EXPECT
CONTINUING REDUCED CIGS/VSBYS IN HEAVIER SHOWERS THIS MORNING
OTHERWISE VFR EXPECTED TO PREVAIL.
MODELS CONTINUE TO SHOW INCREASINGLY DRIER AIRMASS ACROSS NE
SECTIONS TODAY WITH BETTER CHANCES OF SHOWERS OR AN ISOLATED TSTM
ACROSS SRN SECTIONS CLOSER THE THE STATIONARY BOUNDARY AND
DEVELOPING WEAK LOW PRES. ISOLATED TO SCATTERED SHOWERS EXPECTED
TO CONTINUE TONIGHT WITH GREATEST COVERAGE CONTINUING ACROSS
SOUTHWESTERN AREAS POTENTIALLY BRINGING REDUCED CIGS/VSBYS IN
HEAVIER SHOWERS.
LONG TERM /MONDAY THROUGH THU/...
AS OF 330 AM SUNDAY...MVFR CEILINGS/VSBYS POSSIBLE WITH NUMEROUS
SHOWERS AND A FEW TSTMS MONDAY AND MONDAY NIGHT. PRECIPITATION
BECOMES MORE SCATTERED TUESDAY WITH DRIER CONDITIONS ON TAP
WEDNESDAY AND ESPECIALLY THURSDAY AS HIGH PRESSURE BUILDS
SOUTH...WITH VFR CONDITIONS LIKELY. WILL SEE SOME LATE NIGHT
STRATUS AND FOG...ESPECIALLY MONDAY AND TUESDAY NIGHTS...GIVEN
PLENTIFUL LOW-LEVEL MOISTURE AND MVFR AND PERHAPS IFR CONDITIONS
WILL BE POSSIBLE AT TIMES.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 330 AM SUN...HIGH PRES BUILDING IN FROM THE NORTH THROUGH
THE SHORT TERM WHILE A STATIONARY FRONT WILL REMAIN SOUTH OF THE
AREA...GENERALLY BISECTING SOUTH CAROLINA...WHILE WEAK LOW PRES
MOVES TO A POSITION SE OF CAPE FEAR. GENERALLY EXPECT EASTERLY
FLOW AROUND 10-15 KT ACROSS THE WATERS THROUGH THIS EVENING...
THOUGH COULD SEE AROUND 15-20 KT OUTER PORTIONS OF ONSLOW BAY
CLOSER TO THE LOW. MODELS INDICTING 15-20 KT WINDS SPREADING
NORTHWARD LATE TONIGHT COVERING AREAS SOUTH OF OREGON INLET. SEAS
WILL REMAIN AROUND 2-4 FT THROUGH THE SHORT TERM THOUGH COULD SEE
THEM BUILD UP TO 5 FT ACROSS OUTER PORTIONS OF THE CENTRAL WATERS
LATE TONIGHT.
LONG TERM /MONDAY THROUGH THU/...
AS OF 330 AM SUNDAY...LITTLE CHANGE IN OVERALL PATTERN FOR THE
EXTENDED PERIOD. FRONTAL BOUNDARY REMAINS STALLED TO THE SOUTH AND
EAST OF THE AREA WITH LOW PRESSURE SLIDING ALONG THE FRONT. AS THE
LOW MOVES SHIFT TO THE NORTH MONDAY EVENING INTO TUESDAY...EXPECT
E/SE WINDS TO INCREASE TO 15 TO 20 KNOTS AT TIMES AND SEAS TO
BUILD TO AS HIGH AS 5 FEET. LOCAL SWAN MODEL INDICATES A FEW SMALL
AREAS OF 6 FOOT SEAS...BUT WILL CAP AT 5 FEET FOR NOW. WINDS VEER
TO SOUTHWEST AS LOW MOVES NORTH OF THE AREA TUESDAY THEN BECOME
W/NW BEHIND THE FRONT IN THE EARLY TO MIDDAY PORTION OF WEDNESDAY.
AS HIGH PRESSURE BUILDS SOUTH...WINDS BECOME NORTH ON THURSDAY.
THE COMBINATION OF HIGH ASTRONOMICAL TIDES AND LONG PERIOD SWELLS
WILL KEEP THE RIP CURRENT THREAT IN THE MODERATE CATEGORY TODAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SK
NEAR TERM...SK
SHORT TERM...SK
LONG TERM...CTC
AVIATION...CTC/SK
MARINE...CTC/SK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
404 AM CDT SUN AUG 10 2014
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 402 AM CDT SUN AUG 10 2014
UPPER LEVEL TROUGH OVER GULF OF AK WILL DEEPEN A BIT AND MOVE EAST.
DOWNSTREAM RIDGE/TROUGH AMPLIFIES OVER WESTERN CANADA/NORTHERN
PLAINS AND GREAT LAKES RESPECTIVELY THIS PERIOD AND PATTERN ALSO
SHIFTS EAST.
COLD FRONT WAS MOVING INTO THE FORECAST AREA THIS MORNING.
PRECIPITABLE WATER WAS OVER 1.5 INCHES ON THE MN SIDE OF THE RED
RIVER AND IS FORECAST TO DECREASE UNDER THREE QUARTERS OF AN INCH BY
THIS EVENING. DEEP MOISTURE WOULD SUGGEST WARM RAIN PROCESSES ARE
POSSIBLE TODAY MAINLY ON THE MN SIDE. BULK SHEAR ONLY 15 TO 20
KNOTS MOST OF THE DAY. UPPER LEVEL JET DIGS IN FROM THE NORTHWEST
TONIGHT AS RIDGE/TROUGH AMPLIFIES. BUT CLOD FRONT IS OUT OF THE AREA
BY THEN.
LINE OF SHOWERS AND THUNDERSTORMS OVER THE DEVILS LAKE BASIN WAS
MOVING SOUTHEAST AT 15 TO 20 KNOTS.
LITTLE CHANGE TO TEMPS. TWEAKED POPS FOR TODAY AND TONIGHT.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 402 AM CDT SUN AUG 10 2014
WEDNESDAY THRU SATURDAY...
WEDNESDAY AND THURSDAY...THE RIDGE REBOUNDS WITH HEIGHTS AND
THICKNESS VALUES INCREASING TO SUPPORT A RETURN TO SUBSIDENCE...AND
WARMER TEMPERATURES. ACCOMPANYING SFC HIGH PRESSURE WILL BRING
PARTLY CLOUDY SKIES...LIGHT WINDS...AND LOWERED CHANCES FOR PCPN.
FOR FRIDAY INTO SATURDAY...A CHANGE IN THE PATTERN IS EXPECTED AS
MODELS INDICATE A VIGOROUS 500MB WAVE CROSSING THE NRN PLAINS LATE
IN THE PERIOD. THERE IS SOME UNCERTAINTY IN THE TIMING OF THIS
FEATURE ATTM...SO USED AN ECMWF/GFS BLEND AS THEY WERE THE MORE
CONSISTENT MODELS. THUS...INCREASED POPS ACCORDINGLY FOR THE END OF
THE PERIOD TO REFLECT ANTICIPATED MOVEMENT OF THE SYSTEM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1137 PM CDT SAT AUG 9 2014
EARLIER IDEA WAS WHAT TO MAKE OF SOME MODELS SHOWING MVFR CIGS
BEHIND FRONT SUNDAY MORNING. LATEST GFS MOS AND RAP BACKING OFF
BUT DO SHOW BRIEF PERIOD OF LOW END VFR CIGS MAYBE MVFR CIGS.
FRONTAL TIMING IS A BIT SLOWER SO DELAYED WIND SHIFT INTO GFK TIL
10Z OR SO THEN 13Z-15Z IN FAR-TVF AND CLOSER TO 18Z BJI. NORTH
WINDS 10 TO 25 KTS BEHIND THE FRONT SUNDAY AFTN IN GFK-DVL REGION.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...HOPPES
LONG TERM...HOPKINS
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1151 PM CDT SAT AUG 9 2014
.UPDATE...
ISSUED AT 1137 PM CDT SAT AUG 9 2014
FRONT IS A SLOW MOVER STILL MOVING SLOWLY EAST..JUST PASSED ROLLA-
RUGBY-ROLLA THEN EXTENDS TOWARD BISMARCK AREA. MOTION EASTWARD
SLOWED DOWN PERHAPS BY UPPER LEVEL VORT MOVING INTO WCNTRL MN.
MOST OF THE ACTIVITY ALONG SRN END OF FRONT HAS DISSIPATED BUT
STILL GOT A FEW STORMS WEST OF HARVEY THEN NORTHEAST TO WEST OF
LANGDON. A FEW CORES UP THERE ENOUGH FOR SOME SMALL HAIL NORTHWEST
OF LANGDON. RAP SHORT RANGE MODELS INDICATES THOUGH INSTABILITY
CONTINUES TO WEAKEN OVERNIGHT AS CAPES DIMINISH WELL DOWN TO NR
500 J/KG OR LESS AND AS MENTIONED EARLIER EFFECTIVE BULK SHEAR IS
WEAK. UPPER LEVEL VORT MOVING INTO WCNTRL MN HAS MEANT SHOWERS
HAVE EXITED NE SD AND MUCH OF GRANT CO MN AND THUS TRIMMED POPS A
BIT ALONG SD BORDER TO BETTER MATCH UPDATE FROM WFO ABR/MPX.
BASICALLY KEPT ISOLD TO SCT -SHRA THRU THE NIGHT OVER THE
AREA...WITH ISOLD THUNDER MENTION ALONG FRONT IN NE ND/NRN RRV
OVERNIGHT. LESS BULLISH ON RAINFALL SUNDAY IT APPEARS FARTHER EAST
INTO EASTERN/SOUTHEASTERN FCST AREA AS UPPER LOW MOVING A BIT
FARTHER EAST AND MAY NOT HOOK UP WITH FRONT UNTIL FARTHER EAST.
STILL THOUGH WILL KEEP SOME HIGHER POPS IN FAR EAST-SOUTHEAST AS
AT LEAST A BIT MORE COVERAGE OF SHOWERS EXPECTED MID MORNING
SUNDAY INTO SUNDAY AFTN.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 230 PM CDT SAT AUG 9 2014
FORECAST CHALLENGES CONCERN PCPN CHANCES NEXT 24 HOURS AND TEMPERATURES.
MODELS OVERALL IN PRETTY GOOD AGREEMENT AND WILL USE BLEND FOR
FORECAST.
A COUPLE OF AREAS OF PCPN TO WATCH TONIGHT. FIRST WILL BE ONGOING
WEAK CONVECTION ACROSS SOUTH HALF OF FA ASSOCIATED WITH FORCING
AROUND SURFACE AND MID LEVEL LOW IN SD. MOST CONCENTRATED SHOWERS
REMAIN ACROSS THE FAR SOUTH WITH A LITTLE MORE FAVORABLE LOW LEVEL
CONVERGENCE AND INSTABILITY. BANDS OF LIGHT PCPN CONTINUE TO LIFT
NORTH SO MAINTAIN SOME LOW POPS THIS EVENING. NEXT AREA OF PCPN
WILL BE ALONG COLD FRONT ENTERING THE FA LATE THIS EVENING
ASSOCIATED WITH NORTHERN STREAM SHORT WAVE. OVERALL
INSTABILITY/CAPE/SHEAR FAIRLY WEAK WITH BOTH AREAS SO STRONG STORMS NOT
ANTICIPATED. PRECIPITABLE H2O VALUES > AN INCH SO COULD SEE SOME
LOCALLY HEAVY RAINERS. COLD ADVECTION WITH CFP WILL BE LATE SO
TEMPERATURES OVERALL WILL BE MILDER WITH HIGHER DEWPOINTS.
ABOVE MID LEVEL FEATURES MERGE LATE TONIGHT INTO SUNDAY SO COULD
SEE BETTER CONCENTRATION OF SHOWERS ALONG BOUNDARY AS IT PUSHES
ACROSS VALLEY REGION AND WESTERN MN SUNDAY. WITH CLOUDS/PCPN AND
COOLER COLUMN TEMPERATURES WILL BE COOLER.
ANY LINGERING SHOWERS ACROSS THE EASTERN FA WILL PUSH EAST DURING
THE EVENING WITH CLEARING FROM WEST TO EAST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 230 PM CDT SAT AUG 9 2014
HIGH PRESSURE WILL BUILD IN FOR EARLY NEXT WEEK WITH GRADUAL
WARMING TREND AND DRY WEATHER.
TUESDAY NIGHT TO SATURDAY...THE NW FLOW ALOFT WHICH HAS DOMINATED
THE WEATHER PATTERN FOR MUCH OF THE LAST MONTH CONTINUES WITH
SEASONAL TEMPS AND SFC HIGH PRESSURE OVER THE NORTHERN PLAINS
THROUGH THURSDAY. UNCERTAINTY ENTERS THE FORECAST AS 12Z MODELS
SIGNAL A CHANGE IN THE PATTERN WITH A RATHER POTENT 500MB WAVE
DISLODGING WESTERN CONUS RIDGE BY WEDNESDAY. MODELS BRING THIS WAVE
AND ITS PCPN INTO THE FORECAST AREA LATE THURSDAY PM INTO FRIDAY.
WILL KEEP THE CHC POPS THURSDAY PM AND ONWARD THOUGH UNCERTAINTY
WITH HOW THE FEATURE EVOLVES REMAINS RATHER HIGH GIVEN THE
PERSISTENCE OF THE WESTERN CONUS RIDGE AND POOR MODEL PERFORMANCE
LATELY AT THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1137 PM CDT SAT AUG 9 2014
EARLIER IDEA WAS WHAT TO MAKE OF SOME MODELS SHOWING MVFR CIGS
BEHIND FRONT SUNDAY MORNING. LATEST GFS MOS AND RAP BACKING OFF
BUT DO SHOW BRIEF PERIOD OF LOW END VFR CIGS MAYBE MVFR CIGS.
FRONTAL TIMING IS A BIT SLOWER SO DELAYED WIND SHIFT INTO GFK TIL
10Z OR SO THEN 13Z-15Z IN FAR-TVF AND CLOSER TO 18Z BJI. NORTH
WINDS 10 TO 25 KTS BEHIND THE FRONT SUNDAY AFTN IN GFK-DVL REGION.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...VOELKER
LONG TERM...JK/VOELKER
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
322 PM EDT SUN AUG 10 2014
.SYNOPSIS...
STRENGTHENING LOW PRESSURE IN OHIO VALLEY LIFTS NORTHEAST INTO NORTHERN
OHIO BY MONDAY EVENING. DEEPER MOISTURE LIFTS NORTHEAST AS STEERING
FLOW INCREASES. COLD FRONT LONG ABOUT LATE TUESDAY. DRIER WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
DESPITE THE STEERING FLOW INCREASING ON MONDAY...STILL CONCERNED
ABOUT DOWNPOURS THROUGH THIS NEAR TERM...WITH THIS HAZARD ALSO
SPILLING OVER INTO MONDAY NIGHT.
WITH THE SOUTHEAST LOW LEVEL FLOW REMAINING INTO MONDAY...THE MOST
UNSTABLE AIR EXPECTED TO REMAIN IN THE TRI STATE OF SOUTHERN OHIO
AND EASTERN KENTUCKY OVERNIGHT...BEFORE INCREASING FURTHER EAST LATE
MONDAY AFTERNOON. AS OF MID AFTERNOON ON SUNDAY...WE ARE STILL
TAKING THE ATTITUDE OF MONITORING THE RADAR AND NEAR TERM MODELS...
BEFORE POSTING ANY FLASH FLOOD WATCH HEADLINE. OF COURSE...OUR
SOUTHERN WV COAL FIELD COUNTIES ARE MOST VULNERABLE...WITH CONCERNS
ABOVE 1.5 INCHES. BUT EVEN IN OUR DRIER COUNTIES...THE FLASH FLOOD
THREAT REMAINS. WILL CONTINUE THE HAZARDS IN THE HAZARDOUS WEATHER
POTENTIAL.
WILL LEAVE HEAVY RAIN MENTIONED WITH HIGHER POPS THROUGH MONDAY.
THE SOUTHEAST LOW LEVEL FLOW INCREASES OVERNIGHT...AS THE MID LEVELS
STARTS TURNING OUT OF THE SOUTH AND SOUTHWEST. 12Z MODELS AGREEING
MORE WITH THE RAP PULLING THE INITIAL DEEPER MOISTURE NORTH
OVERNIGHT INTO EASTERN OHIO AND NORTHERN WEST VIRGINIA BY MONDAY
MORNING. WILL HAVE A BAND OF HIGHER POPS WITH THAT...COVERAGE STILL
DEBATABLE WITH THE SE LOW LEVEL FLOW ALONG THE WESTERN SLOPES.
THE NAM STILL TRIES TO ANOTHER PCPN MAX ALONG THE EASTERN SLOPES IN
POCAHONTAS COUNTY...BUT NOT SOLD ON THAT SOLUTION.
AFTER THE MORNING SHOWERS LIFT NORTH...HAVE HIGHER POPS DEVELOPING
IN THE AFTERNOON OVER OHIO AND KENTUCKY MOVING INTO WV LATE IN THE
DAY.
STILL WORKING ON FINE TUNING TEMPERATURES FOR TONIGHT AND MONDAY BUT
DO NOT FORESEE ANY MAJOR CHANGES.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
SURFACE LOW WILL BE MOVING THROUGH THE GREAT LAKES TUESDAY INTO
WEDNESDAY...WITH UPPER LEVEL TROUGH APPROACHING FROM THE WEST. HAVE
COLD FRONT CROSSING TUESDAY...WITH A SECONDARY SURFACE TROUGH/COLD
FRONT TUESDAY EVENING INTO TUESDAY NIGHT. CAPE TOPS 1000J/KG
TUESDAY...AND WITH CONVERGENCE ALONG THE FRONT HELPING...CANNOT
RULE OUT A STRONGER CELL OR TWO TUESDAY. WITH UPPER TROUGH LAGGING
BEHIND HAVE SOME CHANCE POPS...MAINLY IN THE MOUNTAINS...LINGERING
INTO WEDNESDAY MORNING WITH CLOUDS BREAKING UP FROM WEST TO EAST
THROUGH THE DAY.
BLENDED IN BIAS-CORRECTED CONSENSUS GUIDANCE FOR HIGHS AND
LOWS...RESULTING IN MINIMAL CHANGES TO PREVIOUS FORECAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
PRECIP SHOULD BE GONE BY THE START OF THE LONG TERM...WITH A FAIRLY
DRY FORECAST INTO THE WEEKEND WITH SURFACE HIGH PRESSURE. DO HAVE
WEAK NW FLOW ALOFT...SO COULD HAVE A VORT MAX SLIDE THROUGH AT SOME
POINT...BUT CONFIDENCE TOO LOW TO PLUG ANYTHING SPECIFIC IN. STAYED
FAIRLY CLOSE TO WPC GUIDANCE THROUGH THE PERIOD.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
THE LAST DAY OF THE WEAK STEERING MID LEVEL FLOW INTO THIS
EVENING...BEFORE INCREASING BY 12Z MONDAY. THE LOW LEVEL FLOW WILL
BE INCREASING SOONER...INCREASING OVERNIGHT.
WITH THE LOW LEVEL FLOW INCREASING AND THE DEEPER MOISTURE LIFTING
NORTH OVERNIGHT...DID NOT HIT THE TRADITIONAL LATE SUMMER FOG. WITH
THE SE LOW LEVEL FLOW HOLDING...STILL LEAVING WIDESPREAD LOW STRATUS
OVERNIGHT NEAR 1 THSD FT ALONG THE EASTERN SLOPES...INCLUDING
BKW...WITH VSBY NEAR 3 MILES IN SHOWERS OR EVEN DRIZZLE.
WEST OF THE MOUNTAINS...DEEPER MOISTURE LIFTING NORTH...REACHING PKB
TO CKB BY 12Z MONDAY. FIGURING BAND OF SHOWERS ASSOCIATED WITH THAT
DEEPER MOISTURE WITH WIDESPREAD CEILINGS DEVELOPING AT 2 TO 3 THSD FT
AND VSBY NEAR 3 MILES IN THE PCPN. SOME EMBEDDED THUNDER LIMITED TO
THE OHIO VALLEY COUNTIES OVERNIGHT...INCLUDING HTS. THE SE FLOW
SHOULD KEEP AREAS FURTHER EAST MORE STABLE. LOCALIZED DOWNPOURS
COULD BRIEFLY LOW VISIBILITY LOWER THAN SPECIFIC TAF FORECAST.
THE MORNING SHOWERS SHOULD BE LIFTING NORTH OUT OF NORTHERN WEST
VIRGINIA BY 18Z...BUT MORE UNSTABLE AIR WILL START REFORMING SHOWERS
AND THUNDERSTORMS IN OHIO AND KENTUCKY BY 18Z.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: THE COVERAGE AND INTENSITY OF SHOWERS OR STORMS
COULD VARY...PLUS HOW QUICKLY THE SHOWERS MOVE NORTH INTO
NORTHERN WEST VIRGINIA.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
EDT 1HRLY 16 17 18 19 20 21 22 23 00 01 02 03
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY M M H H M M M M M M H H
BKW CONSISTENCY H H M M M M M M L L M L
EKN CONSISTENCY H H H H H M M M M H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z MONDAY...
IFR CONDITIONS IN ROUNDS OF SHOWERS AND THUNDERSTORMS EXPECTED
MONDAY AFTERNOON INTO TUESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...KTB
SHORT TERM...MZ
LONG TERM...MZ
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
215 PM EDT SUN AUG 10 2014
.SYNOPSIS...
STRENGTHENING LOW PRESSURE IN OHIO VALLEY LIFTS NORTHEAST INTO NORTHERN
OHIO BY MONDAY EVENING. DEEPER MOISTURE LIFTS NORTHEAST AS STEERING
FLOW INCREASES. COLD FRONT LONG ABOUT LATE TUESDAY. DRIER WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
DESPITE THE STEERING FLOW INCREASING ON MONDAY...STILL CONCERNED
ABOUT DOWNPOURS THROUGH THIS NEAR TERM...WITH THIS HAZARD ALSO
SPILLING OVER INTO MONDAY NIGHT.
WITH THE SOUTHEAST LOW LEVEL FLOW REMAINING INTO MONDAY...THE MOST
UNSTABLE AIR EXPECTED TO REMAIN IN THE TRI STATE OF SOUTHERN OHIO
AND EASTERN KENTUCKY OVERNIGHT...BEFORE INCREASING FURTHER EAST LATE
MONDAY AFTERNOON. AS OF MID AFTERNOON ON SUNDAY...WE ARE STILL
TAKING THE ATTITUDE OF MONITORING THE RADAR AND NEAR TERM MODELS...
BEFORE POSTING ANY FLASH FLOOD WATCH HEADLINE. OF COURSE...OUR
SOUTHERN WV COAL FIELD COUNTIES ARE MOST VULNERABLE...WITH CONCERNS
ABOVE 1.5 INCHES. BUT EVEN IN OUR DRIER COUNTIES...THE FLASH FLOOD
THREAT REMAINS. WILL CONTINUE THE HAZARDS IN THE HAZARDOUS WEATHER
POTENTIAL.
WILL LEAVE HEAVY RAIN MENTIONED WITH HIGHER POPS THROUGH MONDAY.
THE SOUTHEAST LOW LEVEL FLOW INCREASES OVERNIGHT...AS THE MID LEVELS
STARTS TURNING OUT OF THE SOUTH AND SOUTHWEST. 12Z MODELS AGREEING
MORE WITH THE RAP PULLING THE INITIAL DEEPER MOISTURE NORTH
OVERNIGHT INTO EASTERN OHIO AND NORTHERN WEST VIRGINIA BY MONDAY
MORNING. WILL HAVE A BAND OF HIGHER POPS WITH THAT...COVERAGE STILL
DEBATABLE WITH THE SE LOW LEVEL FLOW ALONG THE WESTERN SLOPES.
THE NAM STILL TRIES TO ANOTHER PCPN MAX ALONG THE EASTERN SLOPES IN
POCAHONTAS COUNTY...BUT NOT SOLD ON THAT SOLUTION.
AFTER THE MORNING SHOWERS LIFT NORTH...HAVE HIGHER POPS DEVELOPING
IN THE AFTERNOON OVER OHIO AND KENTUCKY MOVING INTO WV LATE IN THE
DAY.
STILL WORKING ON FINE TUNING TEMPERATURES FOR TONIGHT AND MONDAY BUT
DO NOT FORESEE ANY MAJOR CHANGES.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
CONTINUED ACTIVE IN THE SHORT TERM PERIOD WITH PERSISTENT UPPER
LEVEL TROUGHING OVER THE GREAT LAKES. MONDAY THE UPPER TROUGH AXIS
CONTINUES TO PROGRESS E/SE ACROSS THE LOWER GREAT LAKES WITH
DEEPENING SFC LOW NEAR THE OHIO RIVER AND PROGGED TO BE LOCATED SW
OHIO BY 00Z TUE. OUT AHEAD...THE FORECAST AREA REMAINS UNDER
SOUTHEAST FLOW. VARIOUS OP NWP STILL IN PRETTY GOOD AGREEMENT WITH A
GOOD SLUG OF DEEP LAYER MOISTURE OVER THE AREA BY 12Z MON WHICH WILL
PROGRESS NORTH AND NORTHEAST DURING THE MORNING AND PERHAPS EARLY
AFTERNOON HOURS. LARGE SCALE FORCING FOR ASCENT SQUARELY OVER THE
AREA BY SAME TIME. ADDITIONALLY...WEAK ISENTROPIC LIFT IS NOTED ON
THE 305K-310K SFCS...WHICH IS ALSO REFLECTED IN CORRESPONDING OMEGA
FIELDS. LITTLE IF ANY INSTABILITY IS PRESENT ACROSS ROUGHLY THE
EASTERN HALF OF THE FORECAST AREA...SO NOT EXPECTING HEAVY RAINFALL
AMOUNTS WITH THIS OR HIGH RAIN RATES. BUT WITH THE AFOREMENTIONED
LIFT AND GOOD AMOUNTS OF MOISTURE...DO THINK THAT MANY AREAS WILL
SEE A DECENT SHOT AT AT LEAST SOME LIGHT MEASURABLE PRECIP DURING
THE MORNING HOURS. THE SOUTHEAST FLOW MAY SERVE TO DAMPEN PRECIP
CHANCES AND/OR AMOUNTS EVEN MORE IN THE AREA ROUGHLY BTWN THE I79
CORRIDOR AND THE EASTERN MOUNTAINS.
MONDAY EVENING AND MONDAY NIGHT THE UPPER TROUGH AND SFC LOW
CONTINUE MOVING NORTH/NORTHEAST BECOMING LOCATED OVER SW ONTARIO BY
12Z TUE. A GOOD CONVECTIVE LINE OF SHOWERS/THUNDERSTORMS SHOULD FORM
NEAR AND ALONG THE FRONT...WHICH WILL NEAR THE TRI-STATE AREA AROUND
00Z TUE AND PUSH ACROSS OVERNIGHT MONDAY NIGHT. SOME STORMS MAY BE
ON THE STRONG SIDE AS THEY APPROACH THE WESTERN PART OF THE AREA MON
EVE...AND IT WOULD/T BE COMPLETELY OUT OF THE QUESTION TO SEE A
STORM REACH SEVERE LIMITS WITH SHEAR RUNNING AROUND 25-30KTS AND
EL/S UP TO AROUND 39KFT. BUT GIVEN THE PROGGED WIND FIELDS AND WBZ
HEIGHTS UPWARDS OF 14KFT PLUS...NOT REALLY EXPECTING SEVERE ACTIVITY.
STORMS SHOULD THEN DIMINISH IN INTENSITY AND COVERAGE IN GENERAL
AS THEY CONTINUE EASTWARD AND RUN INTO WANING INSTABILITY.
DEEP LAYER MOISTURE PUSHES EAST OF THE FORECAST AREA BY EARLY TUE.
IT/S POSSIBLE A FEW AREAS NEAR AND WEST OF THE OHIO RIVER ACTUALLY
SEE A FEW BREAKS IN THE CLOUD COVER EARLY. UPPER TROUGH AXIS STILL
REMAINS WEST OF THE AREA HOWEVER AND WITH A GOOD AMOUNT OF LLVL
MOISTURE REMAINING...LOW LEVEL CU FIELD SHOULD REDEVELOP BY MID/LATE
MORNING AREA-WIDE FOR MOSTLY CLOUDY SKIES. NO REAL SFC FEATURE TO
KEY ON FOR ORGANIZED CONVECTIVE DEVELOPMENT...SO WILL KEEP INHERITED
CHANCE POPS FOR TUE. FINALLY BY TUE NIGHT THE SECONDARY STRONGER
FRONT PUSHES ACROSS FROM NW TO SE. PROBABLY WILL SEE SOME SHOWERS
AND A FEW STORMS WITH THE FRONT ITSELF...BUT KEPT POPS AT CHANCE
ONLY WITH A GOOD AMOUNT OF DRY AIR ALOFT POSSIBLY LIMITING COVERAGE.
VERY LITTLE CHANGE FROM PREV FCST WITH MAX AND MIN TEMPS MONDAY
THROUGH TUESDAY NIGHT. STILL EXPECT HIGHS BOTH DAYS IN THE UPPER 70S
AND LOWER 80S LOWLANDS. MINS GENERALLY IN THE UPPER 60S FOR THE
LOWLANDS MONDAY NIGHT. IT WILL BE COOLER TUE NIGHT...ESPECIALLY
NORTHWEST...AS THE SECONDARY FRONT WITH COOLER DRIER AIR MOVES IN.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
COLD FRONT WILL BE CROSSING WV AT THE START OF THE LONG TERM LATE
TUESDAY INTO TUESDAY NIGHT. THE COLD FRONT SHOULD BE GONE BY
MORNING...HOWEVER...HANGING ONTO SOME POPS WITH 500MB TROUGH STILL
CROSSING. GENERAL PATTERN WILL BE SURFACE HIGH PRESSURE WITH A WEAK
RIDGE BUILDING AT 500MB FOR THE END OF THE WEEK. STAYED FAIRLY CLOSE
TO WPC GUIDANCE FOR POPS AND TEMPS THROUGH THE LONG TERM.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
THE LAST DAY OF THE WEAK STEERING MID LEVEL FLOW INTO THIS
EVENING...BEFORE INCREASING BY 12Z MONDAY. THE LOW LEVEL FLOW WILL
BE INCREASING SOONER...INCREASING OVERNIGHT.
WITH THE LOW LEVEL FLOW INCREASING AND THE DEEPER MOISTURE LIFTING
NORTH OVERNIGHT...DID NOT HIT THE TRADITIONAL LATE SUMMER FOG. WITH
THE SE LOW LEVEL FLOW HOLDING...STILL LEAVING WIDESPREAD LOW STRATUS
OVERNIGHT NEAR 1 THSD FT ALONG THE EASTERN SLOPES...INCLUDING
BKW...WITH VSBY NEAR 3 MILES IN SHOWERS OR EVEN DRIZZLE.
WEST OF THE MOUNTAINS...DEEPER MOISTURE LIFTING NORTH...REACHING PKB
TO CKB BY 12Z MONDAY. FIGURING BAND OF SHOWERS ASSOCIATED WITH THAT
DEEPER MOISTURE WITH WIDEPSREAD CEILINGS DEVELOPING AT 2 TO 3 THSD FT
AND VSBY NEAR 3 MILES IN THE PCPN. SOME EMBEDDED THUNDER LIMITED TO
THE OHIO VALLEY COUNTIES OVERNIGHT...INCLUDING HTS. THE SE FLOW
SHOULD KEEP AREAS FURTHER EAST MORE STABLE. LOCALIZED DOWNPOURS
COULD BRIEFLY LOW VISIBILITY LOWER THAN SPECIFIC TAF FORECAST.
THE MORNING SHOWERS SHOULD BE LIFTING NORTH OUT OF NORTHERN WEST
VIRGINIA BY 18Z...BUT MORE UNSTABLE AIR WILL START REFORMING SHOWERS
AND THUNDERSTORMS IN OHIO AND KENTUCKTY BY 18Z.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: THE COVERAGE AND INTENSITY OF SHOWERS OR STORMS
COULD VARY...PLUS HOW QUICKLY THE SHOWERS MOVE NORTH INTO
NORTHERN WEST VIRGINIA.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H M M M H H M M M M M M
BKW CONSISTENCY H H H H M M M M M M L L
EKN CONSISTENCY H H H H H H H M M M M H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z MONDAY...
IFR CONDITIONS IN ROUNDS OF SHOWERS AND THUNDERSTORMS EXPECTED
MONDAY AFTERNOON INTO TUESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...KTB
SHORT TERM...50
LONG TERM...MZ
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
206 PM EDT SUN AUG 10 2014
.SYNOPSIS...
A SLOW MOVING LOW PRESSURE SYSTEM WILL BRING A CHANCE OF SHOWERS
AND A FEW THUNDERSTORMS TODAY NEAR AND SOUTH OF THE OHIO RIVER.
THEN A POTENT UPPER TROUGH RIDING ABOVE THE LOW WILL ENHANCE THE
LIKELIHOOD FOR SHOWERS AND THUNDERSTORMS ON MONDAY AND TUESDAY.
THE SYSTEM WILL MOVE EAST ON WEDNESDAY...USHERING IN A DRY PATTERN
LATER THIS WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MORNING UPDATES WERE GENERALLY FOCUSED ON NORTHERN KENTUCKY. UPPER
LEVEL RIDGE AXIS OVER THE EASTERN GREAT LAKES TODAY...WITH BROAD
LOW PRESSURE IN THE LOWER LEVELS OVER SOUTHERN INDIANA AND A
SURFACE BOUNDARY EXTENDING NEAR OUR SOUTHERN CWA. LIGHT SHOWERS
HAVE BEEN ONGOING SOUTHWEST OF CINCINNATI...BUT MORE EFFICIENT
RAINERS NEAR AND SOUTH OF LEXINGTON. THIS WILL BE THE FOCUS AREA
FOR PRECIPITATION DEVELOPMENT TODAY. BASED ON CONVECTION ALLOWING
MODELS...INCREASED POPS TO LIKELY IN NORTHERN KENTUCKY...BUT
MAINTAINED A SHARP NORTHERN GRADIENT WITH DRIER EASTERLY FLOW
FARTHER NORTH MUCH LIKE PAST FEW DAYS. WILL HAVE TO WATCH
THOUGH...AS HRRR TRIES TO PUSH SOME CONVECTION NORTHWARD BY THIS
EVENING. INSTABILITY WILL NOT BE GREAT AND WILL NOT BE AIDED BY
SURFACE HEATING EITHER...BUT ENOUGH TO RESUME THUNDERSTORM MENTION
THIS AFTERNOON. WITH HIGH PRECIPITABLE WATER AND SLOW
MOVEMENTS...SOME POCKETS OF MODERATE TO HEAVY RAIN ARE POSSIBLE.
WITH EXTENSIVE CLOUD COVER AND PRECIPITATION
POTENTIAL...TEMPERATURES MAY STRUGGLE TO REACH 80 TODAY IN THE FAR
SOUTH. WITH MORE SUNSHINE TOWARD CENTRAL OHIO...THE MID 80S WILL
BE EASILY ATTAINABLE...IF NOT A FEW CLICKS HIGHER IN A SPOTS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
TONIGHT THE H5 RIDGE IS SHUNTED EWD AS SHORTWAVE ENERGY DIGS SOUTH
OUT OF CANADA INTO THE UPPER MS VALLEY. THIS PRODUCES ENOUGH LIFT
FOR A CHANCE OF A SHOWER OR POSSIBLY A THUNDERSTORM OVERNIGHT.
ON MONDAY THE H5 S/W SWINGS INTO THE REGION. THIS PROVIDES THE
FOCUS FOR A SFC LOW TO DEVELOP. SHOWERS AND THUNDERSTORMS SHOULD
DEVELOP IN THIS ENVIRONMENT. WENT LIKELY POPS BY MONDAY AFTERNOON.
THE SYSTEM PUSHES ACROSS THE REGION LATE MONDAY AFTERNOON INTO
MONDAY EVENING. PCPN CHANCES SHOULD DECREASE AS MONDAY NIGHT
PROGRESSES. ADDITIONAL H5 ENERGY DIGS INTO THE GREAT LAKES ON
TUESDAY SHARPENING THE UPPER LEVEL TROF. CONVECTION SHOULD
REDEVELOP ON TUESDAY WITH THIS UPPER LEVEL SUPPORT.
HIGHS MONDAY WILL BE A LITTLE COOLER...REACHING THE UPPER 70S TO
LOWER 80S...WITH ALL LOCATIONS STAYING IN THE 70S ON TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
BY TUESDAY NIGHT...MODELS ARE IN DECENT AGREEMENT ON EXITING
PRECIPITATION EAST OF OUR AREA AS THE LOW LIFTS NORTHEAST OF OUR
REGION. HIGH PRESSURE WILL BUILD ACROSS THE OHIO VALLEY WEDNESDAY
AND IS EXPECTED TO REMAIN IN THE REGION INTO SATURDAY. MAINLY DRY
WEATHER IS EXPECTED DURING THE LATTER HALF OF THE WEEK...EXCEPT
FOR PERHAPS SOME ISOLATED DIURNAL SHOWERS AND THUNDERSTORMS IN
NORTHWEST FLOW OFF LAKE MICHIGAN ON THURSDAY AND FRIDAY.
TEMPERATURES BEHIND THE DEPARTING LOW MID WEEK ARE EXPECTED TO BE
UP TO SEVERAL DEGREES BELOW NORMAL...WITH A GRADUAL WARMING TREND
TOWARD THE END OF THE WEEK AS RETURN FLOW DEVELOPS AND 500-1000
HPA HEIGHTS INCREASE ACROSS OUR AREA. FORECASTER LATTO SIGNING OFF
AT THE ILN CWA...IT HAS BEEN A FINE EXPERIENCE WORKING HERE.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL LIE NORTHEAST OF THE AREA TODAY WITH BROAD LOW
PRESSURE OVER SOUTHERN INDIANA. A BOUNDARY EXTENDING FROM THE LOW
HAS BEEN THE FOCUS OF SCATTERED SHOWERS IN NORTHERN KENTUCKY...BUT
THESE HAVE HAD DIFFICULTY APPROACHING CINCINNATI. THERE WILL BE A
POSSIBILITY OF SCATTERED SHOWERS IN THE VICINITY THROUGH THE
AFTERNOON...BUT LOW CONFIDENCE AT THIS TIME WILL MEAN THESE WILL
BE HANDLED WITH AMENDMENTS IF THEY DEVELOP CLOSE ENOUGH TO AFFECT
THE TERMINALS. SCATTERED TO BROKEN CUMULUS WILL STRADDLE VFR AND
MVFR LEVELS EXCEPT AT THE COLUMBUS SITES.
COMPLEX FORECAST FOR THE OVERNIGHT HOURS WITH DIFFERING MODEL
SOLUTIONS REGARDING PRECIPITATION EVOLUTION. AS LOW PRESSURE
DEEPENS TO THE WEST UNDER THE INFLUENCE OF AN APPROACHING UPPER
TROUGH...A WARM FRONTAL TYPE BAND OF SHOWERS MAY DEVELOP AND PUSH
NORTHWARD ACROSS THE AREA AFTER MIDNIGHT THOUGH THE EARLY MORNING
HOURS. DID NOT INCLUDE VISIBILITY RESTRICTIONS EXCEPT AT
CVG/LUK...AS THERE IS SOME DOUBT ABOUT HOW WELL SUCH A BAND WILL
HOLD TOGETHER AS IT PUSHES NORTH INTO THE DRIER AIR. THERE MAY BE
A LULL DURING THE MORNING HOURS OF MONDAY BEFORE NUMEROUS SHOWERS
AND THUNDERSTORMS DEVELOP DURING THE AFTERNOON AS THE LOW CROSSES.
FORECAST GUIDANCE INDICATES POSSIBLE IFR CONDITIONS THROUGH MUCH
OF MONDAY...BUT DECIDED AGAINST ISSUING SUCH A PESSIMISTIC
FORECAST AT THIS JUNCTURE SINCE VSBY/CIGS WILL LIKELY DEPEND ON
PRECIPITATION TIMING.
OUTLOOK...SHOWERS AND THUNDERSTORMS WILL CONTINUE TO BE LIKELY
THROUGH MONDAY AFTERNOON AND EVENING.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...SITES/SNYDER
NEAR TERM...SNYDER
SHORT TERM...SITES
LONG TERM...LATTO
AVIATION...SNYDER
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1055 AM EDT SUN AUG 10 2014
.SYNOPSIS...
A SLOW MOVING LOW PRESSURE SYSTEM WILL BRING A CHANCE OF SHOWERS
AND A FEW THUNDERSTORMS TODAY. THEN A POTENT UPPER TROUGH RIDING
ABOVE THE LOW WILL ENHANCE THE LIKELIHOOD FOR SHOWERS AND
THUNDERSTORMS ON MONDAY AND TUESDAY. THE SYSTEM WILL MOVE EAST ON
WEDNESDAY...USHERING IN A DRY PATTERN LATER NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MORNING UPDATES WERE GENERALLY FOCUSED ON NORTHERN KENTUCKY. UPPER
LEVEL RIDGE AXIS OVER THE EASTERN GREAT LAKES TODAY...WITH BROAD
LOW PRESSURE IN THE LOWER LEVELS OVER SOUTHERN INDIANA AND A
SURFACE BOUNDARY EXTENDING NEAR OUR SOUTHERN CWA. LIGHT SHOWERS
HAVE BEEN ONGOING SOUTHWEST OF CINCINNATI...BUT MORE EFFICIENT
RAINERS NEAR AND SOUTH OF LEXINGTON. THIS WILL BE THE FOCUS AREA
FOR PRECIPITATION DEVELOPMENT TODAY. BASED ON CONVECTION ALLOWING
MODELS...INCREASED POPS TO LIKELY IN NORTHERN KENTUCKY...BUT
MAINTAINED A SHARP NORTHERN GRADIENT WITH DRIER EASTERLY FLOW
FARTHER NORTH MUCH LIKE PAST FEW DAYS. WILL HAVE TO WATCH
THOUGH...AS HRRR TRIES TO PUSH SOME CONVECTION NORTHWARD BY THIS
EVENING. INSTABILITY WILL NOT BE GREAT AND WILL NOT BE AIDED BY
SURFACE HEATING EITHER...BUT ENOUGH TO RESUME THUNDERSTORM MENTION
THIS AFTERNOON. WITH HIGH PRECIPITABLE WATER AND SLOW
MOVEMENTS...SOME POCKETS OF MODERATE TO HEAVY RAIN ARE POSSIBLE.
WITH EXTENSIVE CLOUD COVER AND PRECIPITATION
POTENTIAL...TEMPERATURES MAY STRUGGLE TO REACH 80 TODAY IN THE FAR
SOUTH. WITH MORE SUNSHINE TOWARD CENTRAL OHIO...THE MID 80S WILL
BE EASILY ATTAINABLE...IF NOT A FEW CLICKS HIGHER IN A SPOTS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
TONIGHT THE H5 RIDGE IS SHUNTED EWD AS SHORTWAVE ENERGY DIGS SOUTH
OUT OF CANADA INTO THE UPPER MS VALLEY. THIS PRODUCES ENOUGH LIFT
FOR A CHANCE OF A SHOWER OR POSSIBLY A THUNDERSTORM OVERNIGHT.
ON MONDAY THE H5 S/W SWINGS INTO THE REGION. THIS PROVIDES THE
FOCUS FOR A SFC LOW TO DEVELOP. SHOWERS AND THUNDERSTORMS SHOULD
DEVELOP IN THIS ENVIRONMENT. WENT LIKELY POPS BY MONDAY AFTERNOON.
THE SYSTEM PUSHES ACROSS THE REGION LATE MONDAY AFTERNOON INTO
MONDAY EVENING. PCPN CHANCES SHOULD DECREASE AS MONDAY NIGHT
PROGRESSES. ADDITIONAL H5 ENERGY DIGS INTO THE GREAT LAKES ON
TUESDAY SHARPENING THE UPPER LEVEL TROF. CONVECTION SHOULD
REDEVELOP ON TUESDAY WITH THIS UPPER LEVEL SUPPORT.
HIGHS MONDAY WILL BE A LITTLE COOLER...REACHING THE UPPER 70S TO
LOWER 80S...WITH ALL LOCATIONS STAYING IN THE 70S ON TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
BY TUESDAY NIGHT...MODELS ARE IN DECENT AGREEMENT ON EXITING
PRECIPITATION EAST OF OUR AREA AS THE LOW LIFTS NORTHEAST OF OUR
REGION. HIGH PRESSURE WILL BUILD ACROSS THE OHIO VALLEY WEDNESDAY
AND IS EXPECTED TO REMAIN IN THE REGION INTO SATURDAY. MAINLY DRY
WEATHER IS EXPECTED DURING THE LATTER HALF OF THE WEEK...EXCEPT
FOR PERHAPS SOME ISOLATED DIURNAL SHOWERS AND THUNDERSTORMS IN
NORTHWEST FLOW OFF LAKE MICHIGAN ON THURSDAY AND FRIDAY.
TEMPERATURES BEHIND THE DEPARTING LOW MID WEEK ARE EXPECTED TO BE
UP TO SEVERAL DEGREES BELOW NORMAL...WITH A GRADUAL WARMING TREND
TOWARD THE END OF THE WEEK AS RETURN FLOW DEVELOPS AND 500-1000
HPA HEIGHTS INCREASE ACROSS OUR AREA. FORECASTER LATTO SIGNING OFF
AT THE ILN CWA...IT HAS BEEN A FINE EXPERIENCE WORKING HERE.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
A PERSISTENT INVERTED TROUGH NOSING NORTHEAST ALONG THE OHIO RIVER
THROUGH CINCINNATI WILL PERMIT SCATTERED SHOWERS FROM A HIGHER
BASE THIS AFTERNOON. EAST WINDS OVER THE REGION BEYOND THIS TROUGH
WILL BRING A GENERAL DRYING PATTERN NORTH OF THE OHIO RIVER AND
LOWER CHANCES OF VFR RAIN AT ILN/DAY TODAY. THE CMH/LCK TAF SITES WILL
SEE A GENERALLY CLEAR SKIES OUTSIDE OF HIGHER CLOUD COVER AND SOME
FAIR WX CU AT VARIOUS TIMES/LEVELS.
SHOWERS SOUTH AND SOUTHWEST OF CINCY ARE PROGGED TO SPREAD INTO
THE REGION IN ABOUT 5-7 HOURS WHICH REMAINS IN LINE WITH EARLIER
TAFS THAT HAD AN 18Z TIME FOR VFR SHOWERS IN MVFR CIGS. THE
REMAINING TAF SITES WILL SEE THE INCREASED CHANCE FOR A PASSING
SHOWER AFTER 0Z TONIGHT WITH THE EXCEPTION OF CMH/LCK WHICH SHOULD
REMAIN DRY IF NOT CLOUD-FREE. MORE PERSISTENT SHOWERS AND
WIDESPREAD RAINFALL WILL OCCUR AT THE END OF THE TAF VALID PERIOD
AT CVG/LUK AS THE SURFACE LOW TRACKS TOWARDS THE REGION.
OUTLOOK...SHOWERS AND TSTORMS LIKELY MONDAY...ENDING EARLY TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...SITES/SNYDER
NEAR TERM...SNYDER
SHORT TERM...SITES
LONG TERM...LATTO
AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS TULSA OK
311 PM CDT SUN AUG 10 2014
.DISCUSSION...
THE PATTERN ALOFT IS CURRENTLY UNDERGOING AMPLIFICATION IN THE
HIGHER LATITUDES...WITH A SPLIT FLOW BLOCK ALONG THE WEST COAST
AND A TROUGH NOW BEGINNING TO TAKE SHAPE OVER THE NORTHERN PLAINS
INTO THE GREAT LAKES. FARTHER SOUTH...A DISTURBANCE EVIDENT ON WV
IMAGERY OVER THE MID MISSOURI VALLEY WILL TRANSLATE SOUTHEAST
TOWARD THE MID MISSISSIPPI VALLEY BY 12Z MONDAY. AT THE
SURFACE...A WEAK BOUNDARY WILL SLIDE SOUTH ACROSS OUR REGION WITH
THE LEAD DISTURBANCE...WHILE THE REINFORCING PUSH OF SOME COOLER
AND DRIER AIR IN ASSOCIATION WITH THE DEVELOPING GREAT LAKES UPPER
TROUGH ARRIVES LATE TONIGHT INTO MONDAY. THE LATEST HI-RES SHORT
TERM MODELS INCLUDING THE HRRR AND LOCAL WRF ARE NOT VERY EXCITED
IN DEVELOPING CONVECTION THIS EVENING AND OVERNIGHT IN ADVANCE OF
THE BOUNDARY. THE BETTER CHANCES WILL BE OVER THE OZARKS AND OVER
SOUTHEAST OKLAHOMA...WITH SCATTERED POPS MAINTAINED IN THE GRIDS.
RAIN CHANCES WILL QUICKLY BE USHERED OUT OF HERE FROM NORTH TO
SOUTH LATE TONIGHT INTO MONDAY AS THE COOLER...DRIER AIR WORKS ITS
WAY IN.
MUCH OF THE WORK WEEK LOOKS RATHER PLEASANT...ESPECIALLY TUESDAY
AND WEDNESDAY...WITH HIGHS FALLING BACK INTO THE 80S AND LOWS
DROPPING BACK INTO THE 60S AND EVEN 50S IN THE COOLER SPOTS. NICE
PREVIEW OF FALL I WOULD SAY. THE HEAT AND HUMIDITY WILL GRADUALLY
RETURN BY NEXT WEEKEND. MODELS HAVE NOT HAD GOOD RUN TO RUN
CONSISTENCY DURING THIS TIME ON HOW THE PATTERN WILL EVOLVE.
TODAY`S RUNS BRING A DISTURBANCE SOUTHEAST ACROSS THE CENTRAL
PLAINS ON THE EASTERN FRINGES OF A SOUTHERN HI PLAINS RIDGE AND
THUS THERE WILL BE SOME POTENTIAL FOR RAIN BY NEXT WEEKEND AS WELL.
LACY
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 71 90 64 86 / 20 10 0 0
FSM 72 92 67 87 / 40 20 0 0
MLC 72 90 67 87 / 40 20 0 0
BVO 68 90 61 86 / 20 10 0 0
FYV 68 86 61 81 / 30 20 0 0
BYV 68 85 61 79 / 40 20 0 0
MKO 71 90 64 86 / 30 10 0 0
MIO 69 88 60 83 / 40 10 0 0
F10 71 89 66 86 / 30 10 0 0
HHW 73 93 70 90 / 30 30 0 0
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
LONG TERM....30
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
1057 AM CDT SUN AUG 10 2014
.UPDATE...
A FRONTAL BOUNDARY IS MOVING ACROSS NORTHERN PORTIONS OF THE FA
THIS MORNING. ISOLATED TO SCATTERED SHOWERS/STORMS WILL REMAIN
POSSIBLE INTO AT LEAST THIS EVENING WITH THE BEST CHANCE ALONG AND
SOUTH OF THE BOUNDARY. HAVE ADJUSTED POPS/WX GRIDS TO SHOW THIS
AND MADE TWEAKS TO OTHER GRIDS TO SHOW CURRENT TRENDS. UPDATES OUT
SOON.
MAXWELL
&&
.PREV DISCUSSION... /ISSUED 648 AM CDT SUN AUG 10 2014/
AVIATION...
10/12Z TAFS...PRIMARILY VFR FORECAST...WITH BRIEF MVFR POSSIBLE
IN AND NEAR SCATTERED THUNDERSTORMS. OUTFLOW BOUNDARY MOVING
THROUGH SOUTHERN OKLAHOMA EXPECTED TO MIX OUT THIS MORNING SO
SOUTHERLY/SWLY EXPECTED AHEAD OF FRONT WHICH IS AHEAD OF CURRENT
MODEL FORECASTS. FOLLOWED CLOSER TO HRRR MODEL FOR SYNOPTIC
BOUNDARY WHERE SCATTERED STORMS SHOULD DEVELOP THIS AFTERNOON AND
EVENING. MODEL OF CHOICE KEEPS STORMS NEAR THE BOUNDARY MAINLY
OVER SOUTHERN OKLAHOMA AND KSPS TERMINAL THIS EVENING. WILL REMOVE
TSRA FROM NW OK TAFS THIS AFTERNOON BUT KEEP MENTION OF PROB30
ELSEWHERE WITH SOME UNCERTAINTY REMAINING ON TIMING OF CONVECTIVE
INITIATION.
PREV DISCUSSION... /ISSUED 433 AM CDT SUN AUG 10 2014/
DISCUSSION...
SCATTERED TO NUMEROUS SHOWERS AND STORMS EXPECTED TO CONTINUE
THROUGH AT LEAST MID-MORNING WITH REDEVELOPMENT AGAIN THIS
AFTERNOON THROUGH TONIGHT AS SLOW MOVING COLD FRONT PROGRESSES
SOUTHWARD OVER REGION. OUTFLOW BOUNDARY FROM KANSAS MCS
PROGRESSING ACROSS CENTRAL OKLAHOMA AT THIS TYPING. RADAR
DEPICTING TRAPPED WAVE /MULTIPLE BANDS/ STRUCTURE OF
OUTFLOW. NO WONDER THERE IS CURRENTLY A LACK OF ECHOES OVER
CENTRAL PORTIONS OF OKLAHOMA. SHOWERS OVER WEST-CENTRAL OKLAHOMA
EXPECTED TO WEAKEN WITH TIME BUT MAY DRIFT INTO OKC BEFORE
COMPLETELY DISSIPATING.
AS SYNOPTIC BOUNDARY MOVES OVER REGION LATER TODAY AND
TONIGHT...WE WILL KEEP POPS GOING. MODEL AGREEMENT STILL LACKING
WITH RESPECT TO AMOUNT AND LOCATION OF CONVECTION SO WILL NOT GET
CARRIED AWAY WITH HIGH POPS. DRY WEATHER AND LESS HOT TEMPERATURES
EXPECTED FOR MUCH OF THE WEEK BEFORE SHORT-WAVE RIDGING OCCURS
LATE IN THE WEEK. MODELS WANT TO FLATTEN DOWN THIS RIDGE INTO NEXT
WEEKEND TO VARYING DEGREES. MCS ACTIVITY TO OUR NORTH FRIDAY INTO
NEXT WEEKEND WILL ALLOW KEEPING POPS GOING ACROSS MAINLY NORTHERN
OKLAHOMA LATE IN THE FORECAST PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 93 72 91 69 / 30 40 20 10
HOBART OK 95 72 93 68 / 30 40 20 10
WICHITA FALLS TX 98 74 96 71 / 30 30 40 20
GAGE OK 92 67 89 64 / 20 30 10 10
PONCA CITY OK 90 70 89 65 / 20 20 10 10
DURANT OK 95 75 95 71 / 30 30 30 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/09
AREA FORECAST DISCUSSION
NWS NORMAN OK
648 AM CDT SUN AUG 10 2014
.AVIATION...
10/12Z TAFS...PRIMARILY VFR FORECAST...WITH BRIEF MVFR POSSIBLE
IN AND NEAR SCATTERED THUNDERSTORMS. OUTFLOW BOUNDARY MOVING
THROUGH SOUTHERN OKLAHOMA EXPECTED TO MIX OUT THIS MORNING SO
SOUTHERLY/SWLY EXPECTED AHEAD OF FRONT WHICH IS AHEAD OF CURRENT
MODEL FORECASTS. FOLLOWED CLOSER TO HRRR MODEL FOR SYNOPTIC
BOUNDARY WHERE SCATTERED STORMS SHOULD DEVELOP THIS AFTERNOON AND
EVENING. MODEL OF CHOICE KEEPS STORMS NEAR THE BOUNDARY MAINLY
OVER SOUTHERN OKLAHOMA AND KSPS TERMINAL THIS EVENING. WILL REMOVE
TSRA FROM NW OK TAFS THIS AFTERNOON BUT KEEP MENTION OF PROB30
ELSEWHERE WITH SOME UNCERTAINTY REMAINING ON TIMING OF CONVECTIVE
INITIATION.
&&
.PREV DISCUSSION... /ISSUED 433 AM CDT SUN AUG 10 2014/
DISCUSSION...
SCATTERED TO NUMEROUS SHOWERS AND STORMS EXPECTED TO CONTINUE
THROUGH AT LEAST MID-MORNING WITH REDEVELOPMENT AGAIN THIS
AFTERNOON THROUGH TONIGHT AS SLOW MOVING COLD FRONT PROGRESSES
SOUTHWARD OVER REGION. OUTFLOW BOUNDARY FROM KANSAS MCS
PROGRESSING ACROSS CENTRAL OKLAHOMA AT THIS TYPING. RADAR
DEPICTING TRAPPED WAVE /MULTIPLE BANDS/ STRUCTURE OF
OUTFLOW. NO WONDER THERE IS CURRENTLY A LACK OF ECHOES OVER
CENTRAL PORTIONS OF OKLAHOMA. SHOWERS OVER WEST-CENTRAL OKLAHOMA
EXPECTED TO WEAKEN WITH TIME BUT MAY DRIFT INTO OKC BEFORE
COMPLETELY DISSIPATING.
AS SYNOPTIC BOUNDARY MOVES OVER REGION LATER TODAY AND
TONIGHT...WE WILL KEEP POPS GOING. MODEL AGREEMENT STILL LACKING
WITH RESPECT TO AMOUNT AND LOCATION OF CONVECTION SO WILL NOT GET
CARRIED AWAY WITH HIGH POPS. DRY WEATHER AND LESS HOT TEMPERATURES
EXPECTED FOR MUCH OF THE WEEK BEFORE SHORT-WAVE RIDGING OCCURS
LATE IN THE WEEK. MODELS WANT TO FLATTEN DOWN THIS RIDGE INTO NEXT
WEEKEND TO VARYING DEGREES. MCS ACTIVITY TO OUR NORTH FRIDAY INTO
NEXT WEEKEND WILL ALLOW KEEPING POPS GOING ACROSS MAINLY NORTHERN
OKLAHOMA LATE IN THE FORECAST PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 95 72 91 69 / 40 40 20 10
HOBART OK 96 72 93 68 / 40 40 20 10
WICHITA FALLS TX 99 74 96 71 / 30 30 40 20
GAGE OK 93 67 89 64 / 40 30 10 10
PONCA CITY OK 91 70 89 65 / 50 20 10 10
DURANT OK 97 75 95 71 / 30 30 30 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
26/99/11
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1141 PM EDT MON AUG 11 2014
.SYNOPSIS...
DEEP MOISTURE WILL SURGE NORTHWARD OVER THE REGION AS A LARGE
STORM SYSTEM TRACKS THROUGH THE GREAT LAKES TONIGHT AND
TUESDAY. THE RESULT WILL BE OCCASIONAL RAIN AND ISOLATED
THUNDERSTORMS OVER CENTRAL PENNSYLVANIA INTO WEDNESDAY MORNING.
A COLD FRONT WILL EVENTUALLY CROSS THROUGH THE AREA TUESDAY NIGHT
AND WEDNESDAY MORNING. GENERALLY DRIER AND COOLER CONDITIONS ARE
EXPECTED FOR THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
FORECAST ON TRACK WITH JUST A FEW AREAS OF SHOWER ACTIVITY OVER
THE CWA WITH HEAVIER AND MORE WIDESPREAD SHOWERS OVER THE
PITTSBURGH CWA. THIS ACTIVITY WILL MOVE EASTWARD OVERNIGHT AND
POPS WILL RISE SIGNIFICANTLY OVERNIGHT. TEMPERATURES WILL NOT MOVE
TOO MUCH FOR THE REST OF THE NIGHT WITH MOISTURE AND CLOUD COVER
INCREASING.
PREVIOUS DISCUSSION FROM 8PM...SCALED BACK JUST A BIT ON THE
TIMING OF SHOWERS FOR MOST OF THE CWA. ONE BAND OF LIGHT SHOWERS
WEAKENING AS IT SLIDES EASTWARD ALONG THE PA/MD BORDER. MORE
IMPRESSIVE BANDS OF SHOWERS AND SOME THUNDERSTORMS NOT TO FAR FROM
THE OH/PA BORDER AT 00Z. LATEST HRRR RUNS SHOWING THIS BAND WILL
HOLD TOGETHER AND MOVE INTO CWA BY 03Z AND ACROSS THE CWA
OVERNIGHT. WHILE THE POPS WERE LOWERED FOR THE NEXT SEVERAL
HOURS...IT LOOKS QUITE WET FOR THE PRE DAWN HOURS. TEMPERATURES
MILD WITH SOUTHERLY FLOW AND THICK CLOUDS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
THE SFC BASED STABILITY LOOKS TO REMAIN HIGH THROUGHOUT MOST OF
THE UPCOMING EVENT. SOUNDINGS DO LOOK MOIST ADIABATIC SO THUNDER
WILL PROBABLY BE ISOLATED TO POCKETS WHERE BEST FORCING APPEAR.
THE DEEPEST MOISTURE AND AXIS OF STRONGEST WINDS WILL BE BISECT
THE STATE TUESDAY...SO A VERY WET TUESDAY IS IN STORE FOR THE
CENTRAL AREAS IN THE MORNING AND EASTERN LOCATIONS ALL DAY
LONG...AND THROUGH THE NIGHT. SOME LLVL INSTABILITY COULD ENHANCE
THE RAIN RATES IN THE SE HALF OF THE AREA. GIVEN EXTENSIVE CLOUD
COVER AND PRECIPITATION...MOST AREAS WILL REMAIN IN THE U60S AND
L/M70S TUESDAY AFTERNOON.
SPC HAS PLACED MUCH OF THE AREA INTO THE SLIGHT RISK AREA FOR
TUESDAY...BUT WE WILL HAVE TO POKE SOME BIG HOLES IN THE CLOUDS
WHICH LOOK LIKE A FORMIDABLE TASK. THE EXCEPTION TO THIS MAY BE
OVER THE W/SW WHERE DRY AIR MAY SHOVE IN FROM THE WEST IN THE
AFTN. HAVE ONLY MENTIONED SLIGHT CHC THUNDER FOR NOW. THE
SOUNDINGS/CROSS SECTIONS LOOK VERY MOIST THRU MOST OF THE AREA.
UNSETTLED AND WET WEATHER WILL CONTINUE INTO TUESDAY NIGHT AS THE
FRONT PASSES THROUGH MOST OF THE AREA...BEFORE THE UPPER LOW
PUSHES ACROSS NY STATE ON WED/THU. THE FRONT WILL LIKELY HANG UP
AS THE WAVE DEVELOPING ALONG THE COAST MOVES UP TO OUR LATITUDE.
POTENTIAL HEAVIER RAINS WILL BE OVER EASTERN SECTIONS OF CWA
TUESDAY NIGHT.
WITHOUT AN SPECIFIC INTENSE PERIOD OF RAIN/CONVECTION...AND LITTLE
OR NO RAIN IN THE LAST 6-7 DAYS...NO FLOOD WATCH AT THIS POINT.
BUT WILL LEAVE MENTIONS OF HEAVY RAIN POTENTIAL IN THE HWO.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
SOME MODEL SPREAD...CLOUDS COULD REMAIN STUBBORN ACROSS THE MTNS
ON WED...AS COLD POOL ASSOCIATED WITH UPPER LOW REMAINS OVERHEAD.
THE WAVE ALONG THE EAST COAST APPEARS TO SLOW THINGS UP. THUS SOME
SHOWERS AND STORMS STILL LIKELY...AT LEAST EARLY ON. DID NOT MAKE
A LOT OF CHANGES TO THE POPS. STILL A LOT OF MODEL SPREAD ON THE
DETAILS. THIS BEEN THE PATTERN FOR MUCH OF THE SUMMER SO FAR.
STILL A CHC OF A SHOWER ON THU ACROSS THE NORTH WITH THE UPPER
LVL LOW.
AFTER THIS...WENT WITH A DRY FOR FCST INTO NEXT MONDAY. A RATHER
DEEP UPPER LVL LOW WILL SLOWLY LIFT OUT...LEAVING US IN A NW
FLOW OF COOLER AND DRIER AIR.
TEMPS REMAIN BELOW AVERAGE LATE WEEK...WITH A MODERATING TREND
FOR THE WEEKEND AS RIDGE AXIS SLIDES THROUGH OHIO VALLEY. THIS
WILL COINCIDE WITH AN EXTENDED PERIOD OF DRY WEATHER.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
A SLOW-MOVING WARM FRONT WILL APPROACH PENNSYLVANIA FROM THE OHIO
VALLEY TONIGHT...SPREADING LOWERING CIGS AND SHRA INTO THE REGION.
THE REGION OF MOST CONCERN WILL BE THE CENTRAL MTNS...INCLUDING
KJST/KAOO/KUNV/KBFD...WHERE SE FLOW ASCENDING THE HIGHER TERRAIN
IS LIKELY TO RESULT IN IFR CIGS. CIGS HAVE FALLEN TO 900FT AT KJST
AND KAOO AT 03Z AND RAP SOUNDINGS SUGGEST KUNV AND KBFD WILL
FOLLOW SUIT BY ARND 06Z. MDL SOUNDINGS SUGGEST THE LOWER ELEVATION
AIRFIELDS OF KMDT AND KLNS WILL LIKELY GO NO LOWER THAN MVFR LATE
TONIGHT.
A BAND OF STRONG SOUTHERLY WINDS ALOFT WILL MOVE THROUGH THE
REGION LATE TONIGHT AND TUESDAY...ACCOMPANIED BY NUMEROUS SHRA
AND TSRA. WARM FRONT IS EXPECTED TO LIFT INTO THE AREA BY TUE
AFTN...CAUSING CIGS TO RISE A BIT. HOWEVER...TROUGH OF LOW PRES
APPROACHING FROM THE WEST WILL PRODUCE NUMEROUS SHRA/TSRA...WHICH
COULD PRODUCE BRIEF IFR VSBYS AND GUSTY WINDS DURING THE PM HOURS.
AN EXAMINATION OF LATEST MDL SOUNDINGS SUGGESTS WE WILL FALL JUST
SHORT OF LLWS CRITERIA LATE TONIGHT AND EARLY TUE...AS BAND OF
STRONG WINDS ALOFT PASSES OVR PA. HOWEVER...LOCALLY GUSTY SFC
WINDS ARE EXPECTED LATER TONIGHT AND EARLY TUESDAY. BUFKIT
SOUNDINGS SUPPORT OCNL GUSTS BTWN 20-25KTS OVR THE CENTRAL
MTNS AND PERHAPS UP TO 30KTS TUE AM AT KIPT...WHERE TOPOGRAPHY
EFFECTS ENHANCE THE GUST POTENTIAL. ACROSS SE PA...THE WINDS ARE
LIKELY TO BE LIGHTER AT KMDT AND KLNS.
OUTLOOK...
TUE NIGHT...SHRA/TSRA. LOW CIGS/VSBYS POSSIBLE.
WED...AM SHRA/LOW CIGS POSSIBLE.
THU-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...ROSS/DANGELO
SHORT TERM...DANGELO
LONG TERM...DANGELO/MARTIN/RXR
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1039 PM EDT MON AUG 11 2014
.SYNOPSIS...
DEEP MOISTURE WILL SURGE NORTHWARD OVER THE REGION AS A LARGE
STORM SYSTEM TRACKS THROUGH THE GREAT LAKES TONIGHT AND
TUESDAY. THE RESULT WILL BE OCCASIONAL RAIN AND ISOLATED
THUNDERSTORMS OVER CENTRAL PENNSYLVANIA INTO WEDNESDAY MORNING.
A COLD FRONT WILL EVENTUALLY CROSS THROUGH THE AREA TUESDAY NIGHT
AND WEDNESDAY MORNING. GENERALLY DRIER AND COOLER CONDITIONS ARE
EXPECTED FOR THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
FORECAST ON TRACK WITH JUST A FEW AREAS OF SHOWER ACTIVITY OVER
THE CWA WITH HEAVIER AND MORE WIDESPREAD SHOWERS OVER THE
PITTSBURGH CWA. THIS ACTIVITY WILL MOVE EASTWARD OVERNIGHT AND
POPS WILL RISE SIGNIFICANTLY OVERNIGHT. TEMPERATURES WILL NOT MOVE
TOO MUCH FOR THE REST OF THE NIGHT WITH MOISTURE AND CLOUD COVER
INCREASING.
PREVIOUS DISCUSSION FROM 8PM...SCALED BACK JUST A BIT ON THE
TIMING OF SHOWERS FOR MOST OF THE CWA. ONE BAND OF LIGHT SHOWERS
WEAKENING AS IT SLIDES EASTWARD ALONG THE PA/MD BORDER. MORE
IMPRESSIVE BANDS OF SHOWERS AND SOME THUNDERSTORMS NOT TO FAR FROM
THE OH/PA BORDER AT 00Z. LATEST HRRR RUNS SHOWING THIS BAND WILL
HOLD TOGETHER AND MOVE INTO CWA BY 03Z AND ACROSS THE CWA
OVERNIGHT. WHILE THE POPS WERE LOWERED FOR THE NEXT SEVERAL
HOURS...IT LOOKS QUITE WET FOR THE PRE DAWN HOURS. TEMPERATURES
MILD WITH SOUTHERLY FLOW AND THICK CLOUDS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
THE SFC BASED STABILITY LOOKS TO REMAIN HIGH THROUGHOUT MOST OF
THE UPCOMING EVENT. SOUNDINGS DO LOOK MOIST ADIABATIC SO THUNDER
WILL PROBABLY BE ISOLATED TO POCKETS WHERE BEST FORCING APPEAR.
THE DEEPEST MOISTURE AND AXIS OF STRONGEST WINDS WILL BE BISECT
THE STATE TUESDAY...SO A VERY WET TUESDAY IS IN STORE FOR THE
CENTRAL AREAS IN THE MORNING AND EASTERN LOCATIONS ALL DAY
LONG...AND THROUGH THE NIGHT. SOME LLVL INSTABILITY COULD ENHANCE
THE RAIN RATES IN THE SE HALF OF THE AREA. GIVEN EXTENSIVE CLOUD
COVER AND PRECIPITATION...MOST AREAS WILL REMAIN IN THE U60S AND
L/M70S TUESDAY AFTERNOON.
SPC HAS PLACED MUCH OF THE AREA INTO THE SLIGHT RISK AREA FOR
TUESDAY...BUT WE WILL HAVE TO POKE SOME BIG HOLES IN THE CLOUDS
WHICH LOOK LIKE A FORMIDABLE TASK. THE EXCEPTION TO THIS MAY BE
OVER THE W/SW WHERE DRY AIR MAY SHOVE IN FROM THE WEST IN THE
AFTN. HAVE ONLY MENTIONED SLIGHT CHC THUNDER FOR NOW. THE
SOUNDINGS/CROSS SECTIONS LOOK VERY MOIST THRU MOST OF THE AREA.
UNSETTLED AND WET WEATHER WILL CONTINUE INTO TUESDAY NIGHT AS THE
FRONT PASSES THROUGH MOST OF THE AREA...BEFORE THE UPPER LOW
PUSHES ACROSS NY STATE ON WED/THU. THE FRONT WILL LIKELY HANG UP
AS THE WAVE DEVELOPING ALONG THE COAST MOVES UP TO OUR LATITUDE.
POTENTIAL HEAVIER RAINS WILL BE OVER EASTERN SECTIONS OF CWA
TUESDAY NIGHT.
WITHOUT AN SPECIFIC INTENSE PERIOD OF RAIN/CONVECTION...AND LITTLE
OR NO RAIN IN THE LAST 6-7 DAYS...NO FLOOD WATCH AT THIS POINT.
BUT WILL LEAVE MENTIONS OF HEAVY RAIN POTENTIAL IN THE HWO.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
SOME MODEL SPREAD...CLOUDS COULD REMAIN STUBBORN ACROSS THE MTNS
ON WED...AS COLD POOL ASSOCIATED WITH UPPER LOW REMAINS OVERHEAD.
THE WAVE ALONG THE EAST COAST APPEARS TO SLOW THINGS UP. THUS SOME
SHOWERS AND STORMS STILL LIKELY...AT LEAST EARLY ON. DID NOT MAKE
A LOT OF CHANGES TO THE POPS. STILL A LOT OF MODEL SPREAD ON THE
DETAILS. THIS BEEN THE PATTERN FOR MUCH OF THE SUMMER SO FAR.
STILL A CHC OF A SHOWER ON THU ACROSS THE NORTH WITH THE UPPER
LVL LOW.
AFTER THIS...WENT WITH A DRY FOR FCST INTO NEXT MONDAY. A RATHER
DEEP UPPER LVL LOW WILL SLOWLY LIFT OUT...LEAVING US IN A NW
FLOW OF COOLER AND DRIER AIR.
TEMPS REMAIN BELOW AVERAGE LATE WEEK...WITH A MODERATING TREND
FOR THE WEEKEND AS RIDGE AXIS SLIDES THROUGH OHIO VALLEY. THIS
WILL COINCIDE WITH AN EXTENDED PERIOD OF DRY WEATHER.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
A SLOW-MOVING WARM FRONT WILL APPROACH PENNSYLVANIA FROM THE OHIO
VALLEY TONIGHT...SPREADING LOWERING CIGS AND SHRA INTO THE REGION.
THE REGION OF MOST CONCERN WILL BE THE CENTRAL MTNS...INCLUDING
KJST/KAOO/KUNV/KBFD...WHERE SE FLOW ASCENDING THE HIGHER TERRAIN
IS LIKELY TO RESULT IN IFR CIGS. UPSTREAM OBS AND RAP SOUNDINGS
SUGGEST KJST WILL FALL TO IFR BTWN 00Z-03Z...WHILE KAOO/KUNV/KBFD
ARE MORE LIKELY TO TAKE UNTIL ARND 06Z. MDL SOUNDINGS SUGGEST THE
LOWER ELEVATION AIRFIELDS OF KMDT AND KLNS WILL LIKELY GO NO LOWER
THAN MVFR LATE TONIGHT.
A BAND OF STRONG SOUTHERLY WINDS ALOFT WILL MOVE THROUGH THE
REGION LATE TONIGHT AND TUESDAY...ACCOMPANIED BY NUMEROUS SHRA
AND TSRA. WARM FRONT IS EXPECTED TO LIFT INTO THE AREA BY TUE
AFTN...CAUSING CIGS TO RISE A BIT. HOWEVER...TROUGH OF LOW PRES
APPROACHING FROM THE WEST WILL PRODUCE NUMEROUS SHRA/TSRA...WHICH
COULD PRODUCE BRIEF IFR VSBYS AND GUSTY WINDS DURING THE PM HOURS.
AN EXAMINATION OF LATEST MDL SOUNDINGS SUGGESTS WE WILL FALL JUST
SHORT OF LLWS CRITERIA LATE TONIGHT AND EARLY TUE...AS BAND OF
STRONG WINDS ALOFT PASSES OVR PA. HOWEVER...LOCALLY GUSTY SFC
WINDS ARE EXPECTED LATER TONIGHT AND EARLY TUESDAY. BUFKIT
SOUNDINGS SUPPORT OCNL GUSTS BTWN 20-25KTS OVR THE CENTRAL
MTNS AND PERHAPS 30KTS AT KIPT...WHERE TOPOGRAPHY EFFECTS ENHANCE
THE GUST POTENTIAL. ACROSS SE PA...THE WINDS ARE LIKELY TO BE
LIGHTER AT KMDT AND KLNS.
OUTLOOK...
TUE NIGHT...SHRA/TSRA. LOW CIGS/VSBYS POSSIBLE.
WED...AM SHRA/LOW CIGS POSSIBLE.
THU-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...ROSS/DANGELO
SHORT TERM...DANGELO
LONG TERM...DANGELO/MARTIN/RXR
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
824 PM EDT MON AUG 11 2014
.SYNOPSIS...
DEEP MOISTURE WILL SURGE NORTHWARD OVER THE REGION AS A LARGE
STORM SYSTEM TRACKS THROUGH THE GREAT LAKES TONIGHT AND
TUESDAY. THE RESULT WILL BE OCCASIONAL RAIN AND ISOLATED
THUNDERSTORMS OVER CENTRAL PENNSYLVANIA INTO WEDNESDAY MORNING.
A COLD FRONT WILL EVENTUALLY CROSS THROUGH THE AREA TUESDAY NIGHT
AND WEDNESDAY MORNING. GENERALLY DRIER AND COOLER CONDITIONS ARE
EXPECTED FOR THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
SCALED BACK JUST A BIT ON THE TIMING OF SHOWERS FOR MOST OF THE
CWA. ONE BAND OF LIGHT SHOWERS WEAKENING AS IT SLIDES EASTWARD
ALONG THE PA/MD BORDER. MORE IMPRESSIVE BANDS OF SHOWERS AND SOME
THUNDERSTORMS NOT TO FAR FROM THE OH/PA BORDER AT 00Z. LATEST HRRR
RUNS SHOWING THIS BAND WILL HOLD TOGETHER AND MOVE INTO CWA BY 03Z
AND ACROSS THE CWA OVERNIGHT. WHILE THE POPS WERE LOWERED FOR THE
NEXT SEVERAL HOURS...IT LOOKS QUITE WET FOR THE PRE DAWN HOURS.
TEMPERATURES MILD WITH SOUTHERLY FLOW AND THICK CLOUDS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
THE SFC BASED STABILITY LOOKS TO REMAIN HIGH THROUGHOUT MOST OF
THE UPCOMING EVENT. SOUNDINGS DO LOOK MOIST ADIABATIC SO THUNDER
WILL PROBABLY BE ISOLATED TO POCKETS WHERE BEST FORCING APPEAR.
THE DEEPEST MOISTURE AND AXIS OF STRONGEST WINDS WILL BE BISECT
THE STATE TUESDAY...SO A VERY WET TUESDAY IS IN STORE FOR THE
CENTRAL AREAS IN THE MORNING AND EASTERN LOCATIONS ALL DAY
LONG...AND THROUGH THE NIGHT. SOME LLVL INSTABILITY COULD ENHANCE
THE RAIN RATES IN THE SE HALF OF THE AREA. GIVEN EXTENSIVE CLOUD
COVER AND PRECIPITATION...MOST AREAS WILL REMAIN IN THE U60S AND
L/M70S TUESDAY AFTERNOON.
SPC HAS PLACED MUCH OF THE AREA INTO THE SLIGHT RISK AREA FOR
TUESDAY...BUT WE WILL HAVE TO POKE SOME BIG HOLES IN THE CLOUDS
WHICH LOOK LIKE A FORMIDABLE TASK. THE EXCEPTION TO THIS MAY BE
OVER THE W/SW WHERE DRY AIR MAY SHOVE IN FROM THE WEST IN THE
AFTN. HAVE ONLY MENTIONED SLIGHT CHC THUNDER FOR NOW. THE
SOUNDINGS/CROSS SECTIONS LOOK VERY MOIST THRU MOST OF THE AREA.
UNSETTLED AND WET WEATHER WILL CONTINUE INTO TUESDAY NIGHT AS THE
FRONT PASSES THROUGH MOST OF THE AREA...BEFORE THE UPPER LOW
PUSHES ACROSS NY STATE ON WED/THU. THE FRONT WILL LIKELY HANG UP
AS THE WAVE DEVELOPING ALONG THE COAST MOVES UP TO OUR LATITUDE.
POTENTIAL HEAVIER RAINS WILL BE OVER EASTERN SECTIONS OF CWA
TUESDAY NIGHT.
WITHOUT AN SPECIFIC INTENSE PERIOD OF RAIN/CONVECTION...AND LITTLE
OR NO RAIN IN THE LAST 6-7 DAYS...NO FLOOD WATCH AT THIS POINT.
BUT WILL LEAVE MENTIONS OF HEAVY RAIN POTENTIAL IN THE HWO.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
SOME MODEL SPREAD...CLOUDS COULD REMAIN STUBBORN ACROSS THE MTNS
ON WED...AS COLD POOL ASSOCIATED WITH UPPER LOW REMAINS OVERHEAD.
THE WAVE ALONG THE EAST COAST APPEARS TO SLOW THINGS UP. THUS SOME
SHOWERS AND STORMS STILL LIKELY...AT LEAST EARLY ON. DID NOT MAKE
A LOT OF CHANGES TO THE POPS. STILL A LOT OF MODEL SPREAD ON THE
DETAILS. THIS BEEN THE PATTERN FOR MUCH OF THE SUMMER SO FAR.
STILL A CHC OF A SHOWER ON THU ACROSS THE NORTH WITH THE UPPER
LVL LOW.
AFTER THIS...WENT WITH A DRY FOR FCST INTO NEXT MONDAY. A RATHER
DEEP UPPER LVL LOW WILL SLOWLY LIFT OUT...LEAVING US IN A NW
FLOW OF COOLER AND DRIER AIR.
TEMPS REMAIN BELOW AVERAGE LATE WEEK...WITH A MODERATING TREND
FOR THE WEEKEND AS RIDGE AXIS SLIDES THROUGH OHIO VALLEY. THIS
WILL COINCIDE WITH AN EXTENDED PERIOD OF DRY WEATHER.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
A SLOW-MOVING WARM FRONT WILL APPROACH PENNSYLVANIA FROM THE OHIO
VALLEY TONIGHT...SPREADING LOWERING CIGS AND SHRA INTO THE REGION.
THE REGION OF MOST CONCERN WILL BE THE CENTRAL MTNS...INCLUDING
KJST/KAOO/KUNV/KBFD...WHERE SE FLOW ASCENDING THE HIGHER TERRAIN
IS LIKELY TO RESULT IN IFR CIGS. UPSTREAM OBS AND RAP SOUNDINGS
SUGGEST KJST WILL FALL TO IFR BTWN 00Z-03Z...WHILE KAOO/KUNV/KBFD
ARE MORE LIKELY TO TAKE UNTIL ARND 06Z. MDL SOUNDINGS SUGGEST THE
LOWER ELEVATION AIRFIELDS OF KMDT AND KLNS WILL LIKELY GO NO LOWER
THAN MVFR LATE TONIGHT.
A BAND OF STRONG SOUTHERLY WINDS ALOFT WILL MOVE THROUGH THE
REGION LATE TONIGHT AND TUESDAY...ACCOMPANIED BY NUMEROUS SHRA
AND TSRA. WARM FRONT IS EXPECTED TO LIFT INTO THE AREA BY TUE
AFTN...CAUSING CIGS TO RISE A BIT. HOWEVER...TROUGH OF LOW PRES
APPROACHING FROM THE WEST WILL PRODUCE NUMEROUS SHRA/TSRA...WHICH
COULD PRODUCE BRIEF IFR VSBYS AND GUSTY WINDS DURING THE PM HOURS.
AN EXAMINATION OF LATEST MDL SOUNDINGS SUGGESTS WE WILL FALL JUST
SHORT OF LLWS CRITERIA LATE TONIGHT AND EARLY TUE...AS BAND OF
STRONG WINDS ALOFT PASSES OVR PA. HOWEVER...LOCALLY GUSTY SFC
WINDS ARE EXPECTED LATER TONIGHT AND EARLY TUESDAY. BUFKIT
SOUNDINGS SUPPORT OCNL GUSTS BTWN 20-25KTS OVR THE CENTRAL
MTNS AND PERHAPS 30KTS AT KIPT...WHERE TOPOGRAPHY EFFECTS ENHANCE
THE GUST POTENTIAL. ACROSS SE PA...THE WINDS ARE LIKELY TO BE
LIGHTER AT KMDT AND KLNS.
OUTLOOK...
TUE NIGHT...SHRA/TSRA. LOW CIGS/VSBYS POSSIBLE.
WED...AM SHRA/LOW CIGS POSSIBLE.
THU-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...ROSS/DANGELO
SHORT TERM...DANGELO
LONG TERM...DANGELO/MARTIN/RXR
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
803 PM EDT MON AUG 11 2014
.SYNOPSIS...
DEEP MOISTURE WILL SURGE NORTHWARD OVER THE REGION AS A LARGE
STORM SYSTEM TRACKS THROUGH THE GREAT LAKES TONIGHT AND
TUESDAY. THE RESULT WILL BE OCCASIONAL RAIN AND ISOLATED
THUNDERSTORMS OVER CENTRAL PENNSYLVANIA INTO WEDNESDAY MORNING.
A COLD FRONT WILL EVENTUALLY CROSS THROUGH THE AREA TUESDAY NIGHT
AND WEDNESDAY MORNING. GENERALLY DRIER AND COOLER CONDITIONS ARE
EXPECTED FOR THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
BAND OF RAIN MOVING UP FROM THE SOUTHWEST WILL RUN INTO
SUPPRESSIVE EFFECT OF THE UPPER RIDGE OVERHEAD. PLUS WE HAVE DRY
AIR IN THE WELL-MIXED LOW LEVELS WITH DEWPOINTS STILL IN THE 50S.
THE RIDGE IS INCHING EAST AND THE RAIN WILL LIFT NORTHWARD THROUGH
THE EVENING AND EARLY TONIGHT. BUT IT HAS BEEN GETTING EATEN AWAY
AS IT MUST MOISTEN UP THE AIR FROM TOP-DOWN. FORCING LIFTING TO
THE NORTH AS THE STACKED LOW MOVES NORTHWARD. BUT AFTER SUNSET THE
RAIN SHOULD START TO ADVANCE SLOWLY EASTWARD. A BIT OF A BREAK
EXISTS THEN BEFORE DIURNAL CONVECTION OVER FAR WRN PA AND ERN OH.
THIS ACTIVITY IS ONLY EXPECTED TO SURVIVE IN PART AS THE PATTERN
SHIFTS EASTWARD. QPF TONIGHT LOOKS TO BE MAINLY TO THE WEST OF
IPT/MDT...AND PERHAPS EVEN MAINLY TO THE WEST OF UNV.
RAIN RATES OF ONLY A FEW HUNDRETHS AN INCH OR SO PER HOUR IN THE
MAIN PART OF THE BAND WILL PROBABLY BE ENHANCED AS THE ATMOS
MOISTENS AND ADD TO IT SOME SOME ELEVATED INSTABILITY DURING THE
NIGHT. THIS WILL BE DUE TO A HIGHLY ANOMALOUS LLJET AND ASSOCIATED
CONVERGENCE. THE PWATS INCREASE RAPIDLY FROM W-E...TOPPING OUT
AROUND 2 INCHES OVER ALL OF THE AREA. THIS PLUME OF DEEP MOISTURE
WILL BRING WIDESPREAD SHOWERS ACROSS WESTERN AND CENTRAL AREAS
TONIGHT...AND SOME OF THE SHOWERS WILL REACH THE EASTERN FRINGE BY
09Z.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
THE SFC BASED STABILITY LOOKS TO REMAIN HIGH THROUGHOUT MOST OF
THE UPCOMING EVENT. SOUNDINGS DO LOOK MOIST ADIABATIC SO THUNDER
WILL PROBABLY BE ISOLATED TO POCKETS WHERE BEST FORCING APPEAR.
THE DEEPEST MOISTURE AND AXIS OF STRONGEST WINDS WILL BE BISECT
THE STATE TUESDAY...SO A VERY WET TUESDAY IS IN STORE FOR THE
CENTRAL AREAS IN THE MORNING AND EASTERN LOCATIONS ALL DAY
LONG...AND THROUGH THE NIGHT. SOME LLVL INSTABILITY COULD ENHANCE
THE RAIN RATES IN THE SE HALF OF THE AREA. GIVEN EXTENSIVE CLOUD
COVER AND PRECIPITATION...MOST AREAS WILL REMAIN IN THE U60S AND
L/M70S TUESDAY AFTERNOON.
SPC HAS PLACED MUCH OF THE AREA INTO THE SLIGHT RISK AREA FOR
TUESDAY...BUT WE WILL HAVE TO POKE SOME BIG HOLES IN THE CLOUDS
WHICH LOOK LIKE A FORMIDABLE TASK. THE EXCEPTION TO THIS MAY BE
OVER THE W/SW WHERE DRY AIR MAY SHOVE IN FROM THE WEST IN THE
AFTN. HAVE ONLY MENTIONED SLIGHT CHC THUNDER FOR NOW. THE
SOUNDINGS/CROSS SECTIONS LOOK VERY MOIST THRU MOST OF THE AREA.
UNSETTLED AND WET WEATHER WILL CONTINUE INTO TUESDAY NIGHT AS THE
FRONT PASSES THROUGH MOST OF THE AREA...BEFORE THE UPPER LOW
PUSHES ACROSS NY STATE ON WED/THU. THE FRONT WILL LIKELY HANG UP
AS THE WAVE DEVELOPING ALONG THE COAST MOVES UP TO OUR LATITUDE.
POTENTIAL HEAVIER RAINS WILL BE OVER EASTERN SECTIONS OF CWA
TUESDAY NIGHT.
WITHOUT AN SPECIFIC INTENSE PERIOD OF RAIN/CONVECTION...AND LITTLE
OR NO RAIN IN THE LAST 6-7 DAYS...NO FLOOD WATCH AT THIS POINT.
BUT WILL LEAVE MENTIONS OF HEAVY RAIN POTENTIAL IN THE HWO.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
SOME MODEL SPREAD...CLOUDS COULD REMAIN STUBBORN ACROSS THE MTNS
ON WED...AS COLD POOL ASSOCIATED WITH UPPER LOW REMAINS OVERHEAD.
THE WAVE ALONG THE EAST COAST APPEARS TO SLOW THINGS UP. THUS SOME
SHOWERS AND STORMS STILL LIKELY...AT LEAST EARLY ON. DID NOT MAKE
A LOT OF CHANGES TO THE POPS. STILL A LOT OF MODEL SPREAD ON THE
DETAILS. THIS BEEN THE PATTERN FOR MUCH OF THE SUMMER SO FAR.
STILL A CHC OF A SHOWER ON THU ACROSS THE NORTH WITH THE UPPER
LVL LOW.
AFTER THIS...WENT WITH A DRY FOR FCST INTO NEXT MONDAY. A RATHER
DEEP UPPER LVL LOW WILL SLOWLY LIFT OUT...LEAVING US IN A NW
FLOW OF COOLER AND DRIER AIR.
TEMPS REMAIN BELOW AVERAGE LATE WEEK...WITH A MODERATING TREND
FOR THE WEEKEND AS RIDGE AXIS SLIDES THROUGH OHIO VALLEY. THIS
WILL COINCIDE WITH AN EXTENDED PERIOD OF DRY WEATHER.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
A SLOW-MOVING WARM FRONT WILL APPROACH PENNSYLVANIA FROM THE OHIO
VALLEY TONIGHT...SPREADING LOWERING CIGS AND SHRA INTO THE REGION.
THE REGION OF MOST CONCERN WILL BE THE CENTRAL MTNS...INCLUDING
KJST/KAOO/KUNV/KBFD...WHERE SE FLOW ASCENDING THE HIGHER TERRAIN
IS LIKELY TO RESULT IN IFR CIGS. UPSTREAM OBS AND RAP SOUNDINGS
SUGGEST KJST WILL FALL TO IFR BTWN 00Z-03Z...WHILE KAOO/KUNV/KBFD
ARE MORE LIKELY TO TAKE UNTIL ARND 06Z. MDL SOUNDINGS SUGGEST THE
LOWER ELEVATION AIRFIELDS OF KMDT AND KLNS WILL LIKELY GO NO LOWER
THAN MVFR LATE TONIGHT.
A BAND OF STRONG SOUTHERLY WINDS ALOFT WILL MOVE THROUGH THE
REGION LATE TONIGHT AND TUESDAY...ACCOMPANIED BY NUMEROUS SHRA
AND TSRA. WARM FRONT IS EXPECTED TO LIFT INTO THE AREA BY TUE
AFTN...CAUSING CIGS TO RISE A BIT. HOWEVER...TROUGH OF LOW PRES
APPROACHING FROM THE WEST WILL PRODUCE NUMEROUS SHRA/TSRA...WHICH
COULD PRODUCE BRIEF IFR VSBYS AND GUSTY WINDS DURING THE PM HOURS.
AN EXAMINATION OF LATEST MDL SOUNDINGS SUGGESTS WE WILL FALL JUST
SHORT OF LLWS CRITERIA LATE TONIGHT AND EARLY TUE...AS BAND OF
STRONG WINDS ALOFT PASSES OVR PA. HOWEVER...LOCALLY GUSTY SFC
WINDS ARE EXPECTED LATER TONIGHT AND EARLY TUESDAY. BUFKIT
SOUNDINGS SUPPORT OCNL GUSTS BTWN 20-25KTS OVR THE CENTRAL
MTNS AND PERHAPS 30KTS AT KIPT...WHERE TOPOGRAPHY EFFECTS ENHANCE
THE GUST POTENTIAL. ACROSS SE PA...THE WINDS ARE LIKELY TO BE
LIGHTER AT KMDT AND KLNS.
OUTLOOK...
TUE NIGHT...SHRA/TSRA. LOW CIGS/VSBYS POSSIBLE.
WED...AM SHRA/LOW CIGS POSSIBLE.
THU-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...DANGELO/MARTIN/RXR
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
932 PM EDT MON AUG 11 2014
.SYNOPSIS...
A WEDGE OF HIGH PRESSURE WILL GRADUALLY WEAKEN OVER THE WESTERN
CAROLINAS THROUGH TONIGHT. A COLD FRONT WILL APPROACH FROM THE WEST
ON TUESDAY...AND PASS THROUGH THE AREA BY EARLY WEDNESDAY. DRY HIGH
PRESSURE WILL THEN SETTLE OVER THE REGION AND REMAIN THROUGH THE END
OF THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 9 PM EDT...WELL AHEAD OF SFC FRONT LOCATED ACRS TENN
TONIGHT...THE ATMOSPHERE ATOP THE CWFA WILL REMAIN CONDUCIVE TO
ADDITIONAL DEEP CONVECTIVE DEVELOPMENT THANKS TO PWAT VALUES NEARING
140 PERCENT OF NORMAL...SUBTLE ENERGY WITHIN DIGGING MID/UPR
TROUGH...AND BROAD BUT WEAK LLVL UPGLIDE FLOW. GREATEST CVRG IS
EXPECTED ACRS THE NC MTNS/FTHLS WHERE SHOWERS AND ELEVATED TSTMS
WILL BECOMING NUMEROUS. HRRR OUTPUT DOES EXPAND CVRG OVERNIGHT ACRS
NE GA/THE UPSTATE AND THE NC PIEDMONT...ESPECIALLY N/W OF I-85.
BASED ON THIS...SOLID CHANCE POP WILL BE CARRIED FOR THESE LOCALES.
BROADER LIFT BECOMES INCREASINGLY HARDER TO DEFINE AS THE OVERNIGHT
WEARS ON...SO WOULD EXPECT DEEPER CONVECTION TO BECOME INCREASINGLY
SCATTERED AND WITH DIMINISHED INTENSITY TOWARD TUESDAY MORNING.
AS OF 5 PM EDT...WITHIN THE WANING UPGLIDE FLOW ACRS THE NC
PIEDMONT...SHOWER ACTIVITY HAS NOW SHIFTED EAST OF I-77...AND
OUR EASTERN FRINGE COUNTIES WHICH ARE STILL WITHIN THE LLVL
CONFLUENT FLOW STILL STAND THE RISK OF DEEP CONVECTION THRU
SUNSET. VISIBLE IMAGERY SHOWS CU FIELD QUITE SPARSE ACRS THE
UPSTATE/NE GA AND GIVEN THIS LATE HOUR...THINK WE WILL BE HARD
PRESSED TO SEE ANYTHING MORE THAN A ISOLATED SHOWER. NUMEROUS
SHOWERS AND A FEW TSTMS SHOULD CONTINUE TO PERCOLATE/DEVELOP
ACRS THE NC MTNS...CLOSER TO BETTER LARGER SCALE LIFT AND
THE PROXIMITY OF NE TENN INSTABILITY AXIS.
AS OF 230 PM EDT...TRAINING SHOWERS CONTINUE ALONG THE INTERSTATE 77
CORRIDOR THIS AFTN IN THE REGION OF BEST LINGERING UPGLIDE OVER THE
WEAKENING PIEDMONT CAD. DECENT COVERAGE SHOULD REMAIN IN THIS
LOCATION THROUGHOUT THE LATE AFTN HOURS AS WEAK ISENTROPIC LIFT
PERSISTS ALONG WITH DEEP MOISTURE. RAOB AND MODEL SOUNDING
PRECIPITABLE WATER VALUES ARE QUITE HIGH...BUT RAINFALL RATES HAVE
THUS FAR BEEN CONTAINED BY THE LACK OF DEEPER CONVECTION. AS
CONVECTIVE ELEMENTS INCREASE IN INTENSITY WITH IMPROVING
INSTABILITY...THE HYDRO THREAT MAY INCREASE SLIGHTLY. THIS AREA WILL
NEED TO BE MONITORED FOR A FLASH FLOOD WATCH. MEANWHILE...COVERAGE
IS ALSO INCREASING AHEAD OF A DECAYING MCS NEAR THE KY/TN
BORDER...BUT CORFIDI VECTOR STEERING FLOW SHOULD TAKE THIS ACTIVITY
MAINLY N OF OUR AREA THROUGH THE EVENING. ACTIVITY FIRING WEST OF
THIS CONVECTION IS TRAILING BACK INTO THE MORE UNSTABLE AIR ACROSS
CENTRAL TN AT PRESENT. THE BEST LATE DAY AND EVENING COVERAGE ACROSS
THE MTNS MAY RESULT FROM IMPROVING UPPER DIVERGENCE AHEAD OF A WEAK
UPPER JETLET AND AN H5 SHORTWAVE ADVANCING AHEAD OF THE MAIN UPPER
TROUGH. THIS FORCING COULD TRAVERSE THE AREA THROUGH 06Z TO PRODUCE
SCT TO NUMEROUS SHOWERS WITH EMBEDDED THUNDERSTORMS. LOW LEVEL SW
FLOW SHOULD SHIFT THE UPSLOPE FOCUS TO THE SOUTHWEST MTNS...WHILE
THE LINGERING UPGLIDE OVER THE CAD RETREATS NORTHWARD. EXPECT VERY
MILD MINS...WITH LOW CLOUDS AND PATCHY FOG IN THE MOIST BOUNDARY
LAYER AS SHOWERS DIMINISH OVERNIGHT.
ANOTHER ROUND OF UPPER DIVERGENCE WILL ARRIVE OVER AN APPROACHING
COLD FRONT TUE AS THE UPPER LEVEL TROUGH SHARPENS UP TO THE WEST.
DEEP LAYER WIND FIELDS ARE EXPECTED TO IMPROVE SLIGHTLY AHEAD OF THE
TROUGH TUE AFTN...BUT WITH SHEAR VALUES STILL A RELATIVELY WEAK 20
TO 25 KT IN THE SFC TO 6 KM LAYER. THE MAIN INCREASE IN THE SVR TSTM
THREAT WILL RESULT FROM MID LEVEL DRYING THROUGH TUE AFTN AHEAD OF
THE APPROACHING FRONT. IN ADDITION...THE MODEL PROFILES ARE FAIRLY
UNSTABLE EAST OF THE BLUE RIDGE TUE AFTN...WITH SOME 2000 TO 2500
J/KG OF SFC BASED CAPE MAXIMIZING TOWARD INTERSTATE 77 BY LATE DAY.
THE SFC COLD FRONT SHOULD REACH THE MTNS BY LATE AFTN. MAXES WILL
WARM CONSIDERABLY OVER MONDAY VALUES...BUT STILL AT LEAST A CATEGORY
BELOW CLIMO THROUGHOUT.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 2 PM MONDAY...A STRONG SHORT WAVE MOVING TROUGH THE GREAT
LAKES WILL ESTABLISH A LONG WAVE TROUGH ACROSS THE EASTERN U.S. BY
MIDWEEK. 12Z MODELS INDICATE THAT THE ASSOCIATED SURFACE COLD FRONT
WILL BE BI-SECTING THE FORECAST AREA AT 00Z WED AND WILL MOVE EAST
OF THE AREA BY 06Z. PLAN VIEW SBCAPES OFF BOTH THE NAM AND GFS ALONG
AND AHEAD OF THE FRONT ARE FROM 1500-2000J. THEREFORE...EXPECT THAT A
SCT-BROKEN LINE OF THUNDERSTORMS WILL ACCOMPANY THE FRONT. THERE
COULD BE A FEW SEVERE STORMS PER SPC`S 5% SEVERE THREAT ON THEIR DAY
2 CONVECTIVE OUTLOOK. THE FRONT AND ASSOCIATED STORMS SHOULD EXIT
THE AREA TO THE EAST BY 06Z WED WITH A MUCH DRYER AND STABLE AIRMASS
OVERSPREADING THE AREA BY WED MORNING.
IN THE WAKE OF THE FRONT...CP HIGH PRESSURE WILL SETTLE OVER THE
AREA ON WED AND CONTINUE INTO THURSDAY. THUS...THE PERIOD AFTER TUE
EVENING WILL FEATURE DRY WEATHER AND TEMPERATURES ABOUT A CATEGORY PLUS
BELOW NORMAL UNDER THE ANOMALOUSLY LOW UPPER HEIGHTS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 145 PM MONDAY...GLOBAL MODELS INDICATE THAT THE LONG WAVE
TROUGH WILL REMAIN OVER THE AREA THROUGH SATURDAY...BUT UPPER HEIGHTS
WILL BEGIN TO RISE BY THE FIRST OF NEXT WEEK AS AN UPPER TROUGH
APPROACHES FROM THE WEST. IN FACT...A WEAK UPPER RIDGE MAY DEVELOP
OVER THE EASTERN U.S. A WEAKENING DRY COLD FRONT IS FORECAST TO
REACH THE AREA THURSDAY NIGHT. AS IT WASHES OUT...HIGH PRESSURE WILL
RE-ESTABLISH ITSELF OVER THE AREA ON FRIDAY. HIGH PRESSURE WILL THEN
CONTINUE TO CONTROL THE WEATHER THROUGH THE PERIOD. HOWEVER...BY
SUNDAY THE WESTERN ATLANTIC SUBTROPICAL RIDGE WILL BEGIN TO BECOME
THE MAIN INFLUENCE ON THE WEATHER WITH WEAK UPSLOPE FLOW INTO THE
MOUNTAINS AND INCREASING DEWPOINTS. HENCE...A RETURN TO MORE TYPICAL
LATE SUMMER DIURNAL CONVECTION IS EXPECTED...WITH THE HIGHEST
COVERAGE OVER THE MOUNTAINS. TEMPERATURES WILL START OFF ABOUT A
CATEGORY BELOW AVERAGE...BUT WARM TO NEAR CLIMO NUMBERS SUNDAY AND
MONDAY.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
AT KCLT...PRIMARY CONCERN FOR THE TAF PERIOD IS THE REDEVELOPMENT OF
FLIGHT RESTRICTIONS WITHIN THE MOIST BLYR...MAINLY IN THE FORM OF
IFR CIGS OVERNIGHT. THE CONSENSUS AMONG THE LATEST OPERATIONAL AND
ENSEMBLE GUIDANCE CONTINUES TO POINT TOWARD A PERIOD OF IFR/LIFR
CIGS FROM ABT 08-13 UTC AND HAVE TWEAKED THAT GOING TIMING OF LOW
CIGS TO REFLECT THIS. EXPECTING A QUICKER IMPROVEMENT TO VFR TUESDAY
MORNING WITHIN THE LLVL SLY FLOW WITH SHOWER AND THUNDERSTORM
CHANCES INCREASING DURING THE AFTERNOON.
ELSEWHERE...NEAR TERM SENSIBLE WX WILL BE FOCUSED ON ENCROACHING
SHOWERS FROM ERN TENN LEADING TO THE BEST CHANCES FOR A SHOWER/TSTM
AT KAVL LATER THIS EVENING. MANY LOCALES WILL BE DEALING WITH A
PERIOD OF IFR FLIGHT CONDITIONS AGAIN LATE TONIGHT...ALTHOUGH WITH
THE SOUTHERLY FLOW INCREASING ON TUESDAY...A FAST RISE TO VFR IS ON
TAP BEFORE SCATTERED SHOWERS AND THUNDERSTORMS DEVELOP BY AFTERNOON.
OUTLOOK...A COLD FRONT WILL CROSS THE REGION TUESDAY EVENING...WITH
CONTINUED SHOWER AND TSRA CHANCES. DRIER VFR CONDITIONS WILL ARRIVE
POST FROPA WED AND CONTINUE THROUGH LATE WEEK.
CONFIDENCE TABLE...
01-07Z 07-13Z 13-19Z 19-01Z
KCLT MED 79% MED 77% MED 75% MED 76%
KGSP MED 62% MED 73% MED 77% HIGH 100%
KAVL HIGH 81% HIGH 80% HIGH 83% HIGH 100%
KHKY HIGH 85% HIGH 83% HIGH 85% HIGH 100%
KGMU MED 67% HIGH 80% HIGH 80% HIGH 100%
KAND HIGH 97% MED 70% HIGH 82% 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...HG
NEAR TERM...CSH/HG
SHORT TERM...LG
LONG TERM...LG
AVIATION...CSH/HG
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
420 AM EDT SUN AUG 10 2014
.SHORT TERM...(TODAY AND TONIGHT)...MODELS CONTINUE TO OVERDO THE
AMOUNT OF CONVECTION EACH DAY...WITH GFS ONLY USEFUL FOR TEMPERATURE
GUIDANCE. SEEMS TO ME THAT ONCE AGAIN THE MAIN FOCUS FOR DEVELOPMENT
WILL BE DAYTIME HEATING AND OROGRAPHIC CONVERGENCE. THERE IS A WEAK
SURFACE LOW OVER NRN MIDDLE TN AND WRN KY WITH A DEW POINT TEMP
DISCONTINUITY ACROSS WRN PARTS OF EAST TN THIS MORNING. UPPER
RIDGING STILL INDICATED SO DON`T SEE MUCH IN THE WAY OF UPPER LEVEL
SUPPORT. LATEST RAP MODEL RUN DEVELOPS A GREAT DEAL OF CONVECTION
LATER THIS MORNING IN THE VICINITY OF THIS BOUNDARY...WHILE HRRR
SHOWS JUST RANDOM ACTIVITY FOR TODAY.
BASED ON POOR MODEL PERFORMANCE...TAKING A PERSISTENCE APPROACH AND
TRIMMING BACK POPS FOR TODAY AND TONIGHT. KEPT LIKELY POPS THIS
AFTERNOON ACROSS MAINLY WRN HALF OF OUR FORECAST AREA...DOWN TO
CHANCE WITH SCATTERED WORDING ELSEWHERE. RADAR TRENDS SUPPORT JUST
SLIGHT CHANCE TO LOW CHANCE POPS FOR THIS MORNING. TOSSED IN SOME
PATCHY FOG FOR LATE TONIGHT...WITH NO MENTION OF FOG REQUIRED FOR
EARLY TODAY.
WARMER GFS MAX TEMPS ONLY GOOD IF JUST MINIMAL CONVECTION OCCURS
TODAY...SO I OPTED FOR A MOS BLEND. GFS MINS OR A DEGREE WARMER
LOOKED GOOD FOR TONIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)...MONDAY SURFACE LOW HAS
ONLY MOVED NORTH SLIGHTLY INTO THE OHIO VALLEY WITH A STATIONARY
FRONT ACROSS MIDDLE TN AND DRAPED SOUTHEAST ACROSS GA. HIGH
PRESSURE REMAINS ALONG NE US COAST. ANOTHER FRONT LIES BEHIND THE
LEAD SYSTEM OVER THE NORTHERN MS VALLEY. CURRENT FORECAST BRINGS
INCREASING SHOWERS AND STORMS MONDAY INTO TUESDAY AS SURFACE LOW
MOVES THROUGH OHIO VALLEY AND COLD FRONT TO THE NW CATCHES UP WITH
STATIONARY FRONT. SHORTWAVE ENERGY MOVING THROUGH OHIO AND TN
VALLEYS WILL SET OFF SHOWERS AND STORMS MONDAY THROUGH TUESDAY
NIGHT AND EARLY WEDNESDAY. SKIES CONTINUE PARTLY TO MOSTLY CLOUDY
WITH HIGHEST RAIN CHANCES MONDAY AFTERNOON AND EVENING. TUESDAY
AND TUESDAY NIGHT STILL CHANCE POPS AS SECONDARY FRONT APPROACHES.
NW FLOW OF COOLER AND DRIER AIR MASS WILL PREVAIL FROM WEDNESDAY
AFTERNOON THROUGH SATURDAY. MORNING LOWS DROP INTO THE 50S TO
LOWER 60S FOR THIS PERIOD WITH HIGHS IN THE UPPER 70S TO LOWER 80S
WEDNESDAY AND THURSDAY AND THEN SLOWLY WARMING INTO THE 80S FRIDAY
AND SATURDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 87 71 87 71 / 70 50 50 50
KNOXVILLE MCGHEE TYSON AIRPORT, TN 85 70 85 69 / 60 50 60 50
OAK RIDGE, TN 82 70 84 68 / 60 40 60 50
TRI CITIES AIRPORT, TN 81 66 82 65 / 50 50 60 50
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
TG/TD
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1227 PM CDT SUN AUG 10 2014
.AVIATION...
EXPECTING SHRA/TSRA TO CONTINUE TO DEVELOP AND SPREAD INLAND THIS AFTERNOON.
THINGS SHOULD QUIET DOWN THIS EVENING WITH THE LOSS OF HEATING. BRIEF
MVFR CEILINGS POSSIBLE AGAIN TONIGHT INTO MONDAY MORNING...THEN ANTICIPATE
ANOTHER CHANCE OF SHRA/TSRA DEVELOPMENT DURING THE DAY AS ACTIVITY DEVELOPS
NEAR THE COAST AND WORKS ITS WAY INLAND AND A FRONTAL BOUNDARY SAGS
SOUTHWARD INTO THE AREA. ACTIVITY MAY LINGER INTO MONDAY NIGHT AND
TUESDAY MORNING IN ASSOCIATION WITH THE FRONTAL BOUNDARY. 42
&&
.PREV DISCUSSION... /ISSUED 953 AM CDT SUN AUG 10 2014/
UPDATE...
SEE DISCUSSION FOR MORNING UPDATE.
DISCUSSION...
ONLY CHANGE TO FORECAST THIS MORNING WAS TO EXPAND HIGHER POPS
INTO HARRIS COUNTY. HIGH RES HRRR AND RAP INITIALIZED THE BEST
THIS MORNING AND ARE SHOWING COVERAGE CONTINUING TO EXPAND WITH
DAYTIME HEATING. THIS MAKES SENSE AS PWATS REMAIN AROUND 2.00"
THIS MORNING AND A WEAK VORT LOBE REMAINS JUST EAST OF US IN
LOUISIANA. THERE IS ALSO A SHEAR AXIS AT 500 DRAPED ACROSS THE
AREA THIS MORNING WHICH COULD HELP TO SERVE AS A FOCUS. NO OTHER
CHANGES TO FORECAST AT THIS TIME. 23
PREV DISCUSSION... /ISSUED 450 AM CDT SUN AUG 10 2014/
DISCUSSION...
GOES SOUNDER IMAGERY SHOWING PW`S AROUND 2" ACROSS MUCH OF THE
REGION. SIMILAR TO YDAY...EXPECT SCT SHRA/TSRA TO DEVELOP WITH AID
OF DAYTIME HEATING AND SEABREEZE. SIMILAR SET UP PROBABLE FOR
MONDAY.
BY LATE MON AFTN WE`LL NEED TO KEEP AN EYE ON WEAK FRONTAL
BOUNDARY PUSHING THRU N TX. MAJORITY OF MODELS SUGGEST THIS
WILL ALSO TRIGGER PRECIP WHICH SHOULD GRADUALLY SHIFT INTO SE TX
MON NIGHT & TUE MORNING. THE FRONT/WINDSHIFT WILL EVENTUALLY STALL
ACROSS PARTS OF SE TX LATE TUE/WED.
DEEPER MOISTURE (PW`S 2-2.3") WILL POOL ALONG THE FRONT AND
STEERING FLOW WILL WEAKEN CONSIDERABLY MON NIGHT-WED SO WILL NEED
TO BE ON LOOKOUT FOR LOCALLY HEAVY RAIN POTENTIAL. STILL CONSIDERABLE
UNCERTAINTY AS TO HOW THINGS WILL EVENTUALLY PLAY OUT (WHERE FRONT
WILL END UP STALLING ACROSS CWA, TIMING OF PRECIP PERIODS,
MESOSCALE PROCESSES, ETC, ETC). IN SIMILAR SET-UPS IN THE PAST, &
ABSENT MCS DEVELOPMENT, HEAVIEST RAINFALL OCCURRED WHERE FRONTAL
CONVECTION & SEABREEZE COLLIDE. SLIGHTLY INCREASED POPS DURING THE
FIRST HALF OF THE WORK WEEK, BUT SOME TIME PERIODS WILL PROBABLY
NEED TO BE INCREASED CONSIDERABLY IF/WHEN FCST CONFIDENCE & TIMING
IMPROVES.
THE DIFFUSE FRONTAL BOUNDARY SHOULD WASHOUT LATE WED. AMPLIFIED
WESTERN RIDGE SHOULD FLATTEN DURING THE 2ND HALF OF THE WORK WEEK
BUT WE`LL STILL BE SITUATED IN TAIL END OF ERN TROF/WEAKNESS SO
ALTHOUGH RAIN CHANCES SHOULD DIMINISH, THEY WON`T GO TO ZERO. 47
MARINE...
GENERALLY LIGHT ONSHORE WINDS WILL PREVAIL THE NEXT FEW DAYS AS THE
PRESSURE GRADIENT REMAINS WEAK IN RESPONSE TO A WEAK SFC FRONT THAT
IS EXPECTED TO STALL OVER INLAND AREAS OF SE TX. THIS BOUNDARY WILL
LIKELY WASH OUT BY MID WEEK OR SO. THE NEXT SYSTEM MOVING DOWN FROM
THE CENTRAL PLAINS IS FCST TO DEEPEN ACROSS THE TX PANHANDLE BY THE
END OF THE WEEK. THIS COULD PRODUCE STRENGTHENING ONSHORE WINDS FOR
THE END OF THE WEEK/NEXT WEEKEND. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 97 77 98 77 96 / 20 20 30 40 30
HOUSTON (IAH) 95 77 97 77 95 / 40 20 30 40 30
GALVESTON (GLS) 92 83 92 83 92 / 30 20 20 20 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...23
AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
953 AM CDT SUN AUG 10 2014
.UPDATE...
SEE DISCUSSION FOR MORNING UPDATE.
&&
.DISCUSSION...
ONLY CHANGE TO FORECAST THIS MORNING WAS TO EXPAND HIGHER POPS
INTO HARRIS COUNTY. HIGH RES HRRR AND RAP INITIALIZED THE BEST
THIS MORNING AND ARE SHOWING COVERAGE CONTINUING TO EXPAND WITH
DAYTIME HEATING. THIS MAKES SENSE AS PWATS REMAIN AROUND 2.00"
THIS MORNING AND A WEAK VORT LOBE REMAINS JUST EAST OF US IN
LOUISIANA. THERE IS ALSO A SHEAR AXIS AT 500 DRAPED ACROSS THE
AREA THIS MORNING WHICH COULD HELP TO SERVE AS A FOCUS. NO OTHER
CHANGES TO FORECAST AT THIS TIME. 23
&&
.PREV DISCUSSION... /ISSUED 450 AM CDT SUN AUG 10 2014/
DISCUSSION...
GOES SOUNDER IMAGERY SHOWING PW`S AROUND 2" ACROSS MUCH OF THE
REGION. SIMILAR TO YDAY...EXPECT SCT SHRA/TSRA TO DEVELOP WITH AID
OF DAYTIME HEATING AND SEABREEZE. SIMILAR SET UP PROBABLE FOR
MONDAY.
BY LATE MON AFTN WE`LL NEED TO KEEP AN EYE ON WEAK FRONTAL
BOUNDARY PUSHING THRU N TX. MAJORITY OF MODELS SUGGEST THIS
WILL ALSO TRIGGER PRECIP WHICH SHOULD GRADUALLY SHIFT INTO SE TX
MON NIGHT & TUE MORNING. THE FRONT/WINDSHIFT WILL EVENTUALLY STALL
ACROSS PARTS OF SE TX LATE TUE/WED.
DEEPER MOISTURE (PW`S 2-2.3") WILL POOL ALONG THE FRONT AND
STEERING FLOW WILL WEAKEN CONSIDERABLY MON NIGHT-WED SO WILL NEED
TO BE ON LOOKOUT FOR LOCALLY HEAVY RAIN POTENTIAL. STILL CONSIDERABLE
UNCERTAINTY AS TO HOW THINGS WILL EVENTUALLY PLAY OUT (WHERE FRONT
WILL END UP STALLING ACROSS CWA, TIMING OF PRECIP PERIODS,
MESOSCALE PROCESSES, ETC, ETC). IN SIMILAR SET-UPS IN THE PAST, &
ABSENT MCS DEVELOPMENT, HEAVIEST RAINFALL OCCURRED WHERE FRONTAL
CONVECTION & SEABREEZE COLLIDE. SLIGHTLY INCREASED POPS DURING THE
FIRST HALF OF THE WORK WEEK, BUT SOME TIME PERIODS WILL PROBABLY
NEED TO BE INCREASED CONSIDERABLY IF/WHEN FCST CONFIDENCE & TIMING
IMPROVES.
THE DIFFUSE FRONTAL BOUNDARY SHOULD WASHOUT LATE WED. AMPLIFIED
WESTERN RIDGE SHOULD FLATTEN DURING THE 2ND HALF OF THE WORK WEEK
BUT WE`LL STILL BE SITUATED IN TAIL END OF ERN TROF/WEAKNESS SO
ALTHOUGH RAIN CHANCES SHOULD DIMINISH, THEY WON`T GO TO ZERO. 47
MARINE...
GENERALLY LIGHT ONSHORE WINDS WILL PREVAIL THE NEXT FEW DAYS AS THE
PRESSURE GRADIENT REMAINS WEAK IN RESPONSE TO A WEAK SFC FRONT THAT
IS EXPECTED TO STALL OVER INLAND AREAS OF SE TX. THIS BOUNDARY WILL
LIKELY WASH OUT BY MID WEEK OR SO. THE NEXT SYSTEM MOVING DOWN FROM
THE CENTRAL PLAINS IS FCST TO DEEPEN ACROSS THE TX PANHANDLE BY THE
END OF THE WEEK. THIS COULD PRODUCE STRENGTHENING ONSHORE WINDS FOR
THE END OF THE WEEK/NEXT WEEKEND. 41
AVIATION...
WILL LIKELY SEE ANOTHER ROUND OF ISO/WIDELY SCT PCPN ACROSS THE FA
THIS AFTN AS GIVEN THE CONTINUED INFLUX OF MOISTURE FROM THE GULF/
ACTIVE SEABREEZE. BRIEF MVFR CIGS ALSO POSSIBLE ONCE AGAIN TONIGHT
INTO MON MORNING AS THIS PATTERN PERSISTS. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 97 77 98 77 96 / 20 20 30 40 30
HOUSTON (IAH) 95 77 97 77 95 / 40 20 30 40 30
GALVESTON (GLS) 92 83 92 83 92 / 30 20 20 20 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...23
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1100 PM CDT MON AUG 11 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 233 PM CDT MON AUG 11 2014
LATEST WATER VAPOR SATELLITE IMAGERY SHOWING SHORTWAVE TROUGH
SPINNING ACROSS NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN. THE
11.12Z GFS/NAM AND 11.15Z RAP INDICATE DECENT FORCING IN ASSOCIATION
WITH SHORTWAVE TROUGH. THIS IS PRODUCING SHOWERS AND ISOLATED
THUNDERSTORMS MAINLY ACROSS EASTERN MINNESOTA AND MUCH OF
WISCONSIN PER LATEST MOSAIC RADAR.
MAIN CONCERNS TONIGHT ARE DIMINISHING TRENDS OF PRECIPITATION AND
LOW CLOUDS ACROSS THE FORECAST AREA. THE 11.12Z GFS/NAM INITIALIZE
SHORTWAVE TROUGH AND MOISTURE FIELDS WELL PER THE LATEST
VISIBLE/WATER VAPOR SATELLITE IMAGERY. THE 11.12Z GFS/NAM SHOW THE
FORCING TO EXIT THE FORECAST AREA AROUND 06Z TUESDAY AND ASSOCIATED
MOISTURE WITH SHORTWAVE TROUGH BY 12Z TUESDAY. HAVE TRENDED
PRECIPITATION CHANCES AND SKY COVER FOR THIS.
SURFACE RIDGE OVER THE DAKOTAS WILL BUILD INTO MINNESOTA AND
WESTERN WISCONSIN TUESDAY. SUBSIDENCE UNDERNEATH SURFACE HIGH WILL
ALLOW FOR DRY WEATHER CONDITIONS AND BELOW NORMAL TEMPERATURES
ACROSS THE FORECAST AREA.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 233 PM CDT MON AUG 11 2014
WITH SURFACE RIDGE OVERHEAD ACROSS FORECAST AREA...THE 11.12Z
NAM/GFS ARE INDICATING AN INVERSION TO DEVELOP AFTER 06Z WEDNESDAY
PER BUFKIT SOUNDINGS. DUE TO WINDS AROUND 5 KNOTS THROUGH 1500
FEET. EXPECT THE FORMATION OF FOG OVER CENTRAL WISCONSIN AND IN
RIVER VALLEYS WEDNESDAY MORNING.
WEDNESDAY...FORECAST AREA REMAINS UNDER NORTHWEST FLOW ALOFT. THE
11.12Z GFS/NAM SHOW WEAK IMPULSE EMBEDDED IN THE NORTHWEST FLOW
ALOFT TO MOVE OVER PARTS OF THE FORECAST AREA. BUFKIT SOUNDINGS FROM
THE 11.12Z GFS/NAM INDICATE STEEP LOW LEVEL LAPSE RATES AND SOME
INSTABILITY ALOFT DURING THE DAY ACROSS CENTRAL WISCONSIN. THE
11.12Z NAM MORE ROBUST WITH THE INSTABILITY AND LOW LEVEL LAPSE
RATES THAN THE GFS. CANNOT RULE OUT AN ISOLATED SHOWER OR
THUNDERSTORM ACROSS CENTRAL WISCONSIN WEDNESDAY AFTERNOON. FOR
NOW...WILL CONTINUE WITH MENTION OF SPRINKLES OVER THIS AREA.
THE COMBINATION OF THE MAIN AXIS OF ISENTROPIC LIFT WEST OF FORECAST
AREA AND SHORTWAVE RIDGING BUILDING INTO THE REGION THURSDAY...WILL
PROVIDE DRY WEATHER CONDITIONS ACROSS THE AREA. HAVE REMOVED SMALL
PRECIPITATION CHANCES OVER THE WESTERN FORECAST AREA.
MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES THURSDAY NIGHT INTO
MONDAY. THE 11.12Z GFS/GEM/ECMWF ARE IN GOOD AGREEMENT BREAKING DOWN
UPPER LEVEL TROUGH OVER THE EASTERN UNITED STATES THIS WEEKEND AND
DEVELOP WEST TO EAST ZONAL FLOW ACROSS THE CONTINENTAL UNITED
STATES. BIGGEST DIFFERENCE BETWEEN THE MODELS IS TIMING AND
PLACEMENT OF SHORTWAVE TROUGHS EMBEDDED IN THE WEST TO EAST ZONAL
FLOW SATURDAY INTO MONDAY. THE 11.12Z GFS/ECMWF INDICATE DECENT
MOISTURE TRANSPORT AND CONVERGENCE WITH SHORTWAVE TROUGH PUSHING
INTO THE UPPER MIDWEST AND GREAT LAKES REGION SUNDAY INTO MONDAY.
DEPENDING ON TIMING/PLACEMENT OF SURFACE FEATURES/SHORTWAVE
TROUGH...PRECIPITATION CHANCES LOOK REASONABLE ACROSS MUCH OF THE
FORECAST AREA SATURDAY INTO MONDAY. HOWEVER...CONFIDENCE IS LOW ON
THE EXACT TIMING AND PLACEMENT OF THE SURFACE FEATURES/SHORTWAVE
TROUGHS TRACKING INTO THE UPPER MIDWEST AND GREAT LAKES REGION
DURING THIS PERIOD. TEMPERATURES FRIDAY INTO EARLY NEXT WEEK WILL
BE NEAR OR SLIGHTLY BELOW NORMAL ACROSS FORECAST AREA...WITH HIGHS
GENERALLY AROUND 80 DEGREES INTO THE LOWER TO MIDDLE 80S
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1100 PM CDT MON AUG 11 2014
LATEST FOG/STRATUS IMAGERY AND SFC OBS POINTING TO A LOW STRATUS
DECK ACROSS THE CENTRAL PORTION OF WI. SOME THREAT THIS COULD BUILD
WEST UNDER A BUILDING LOW LEVEL INVERSION...WITH RAP/NAM 925 RH
FIELDS KEEPING THIS SATURATION CLOSE TO THE MISSISSIPPI RIVER
THROUGH 12Z TUE. STEERING WINDS ARE NORTHERLY THOUGH...PER VAD WINDS
AND BUFKIT SOUNDINGS. THINK THESE 1.5KFT CLOUDS SHOULD HOLD JUST
EAST OF KLSE...AND WILL CONTINUE TO PAINT THE FORECAST THIS WAY.
TRENDS WILL BE MONITORED...AND UPDATES MADE AS NECESSARY. WINDS
SHOULD STAY UP...CLOSE TO 10 KTS FOR THE NIGHTTIME HOURS. THIS
SHOULD MINIMIZE ANY FOG THREAT.
EXPECT VFR CONDITIONS FOR TUE WITH LATE MORNING/AFTERNOON MIXING
RESULTING IN SOME HIGHER WIND GUSTS.
AN AREA OF HIGH PRESSURE AT THE SFC WILL BUILD IN FROM THE NORTHERN
PLAINS TUE NIGHT. EXPECT SFC WINDS TO GO LIGHT...WITH BUFKIT
SOUNDINGS SHOWING A DEEPENING LIGHT WIND LAYER AT KLSE. IT SHOWS THE
POTENTIAL FOR VALLEY FOG - AND SUB 1SM FOG BY WED MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM....DTJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
907 PM CDT MON AUG 11 2014
.UPDATE...AMPLIFYING UPPER LOW AND SECONDARY SHORT WAVE TROUGH
ROTATING AROUND LOW WILL CONTINUE TO GENERATE SHWR AND ISOLD T
THROUGH THE NIGHT OVER ERN CWA. MODERATE MID-LAYER Q-VECTOR
CONVERGENCE AND MID-LVL DEFORMATION DOES NOT EXIT ERN WI UNTIL
AROUND 12Z. HENCE WL BEEF UP POPS TO CATEGORICAL IN THE NORTHEAST
WITH TIGHT GRADIENT TO THE SOUTHWEST.
&&
.AVIATION/06Z TAFS/...EXPECT MVFR AND POSSIBLY LOWER CLOUDS TO
OVERSPREAD EASTERN TAF SITES NEXT FEW HOURS ACCOMPANIED BY SCT TO
NMRS SHRA. LOW CLOUDS MAY HANG ON THRU MUCH OF TUESDAY AS LOW
LEVEL THERMAL TROF DOES NOT EXIT ERN WI UNTIL TUE NGT.
&&
.MARINE...LIGHT ONSHORE FLOW WILL INCREASE OVERNIGHT AND TURN MORE
NORTH TO NORTHEAST AS SFC LOW PRESSURE DEEPENS OVER THE CENTRAL
GREAT LAKES. STILL EXPECT WIND GUSTS TO EXCEED 20 KNOTS BY LATE
TONIGHT AND EARLY TUESDAY...HENCE WL CONTINUE WITH SMALL CRAFT
ADVISORY START TIMES. EXPECT HIGHEST WAVES ON TUESDAY TO BE TOWARD
THE OPEN WATER
&&
.BEACHES...DUE TO SFC WINDS EXPECTED TO BECOME MORE NORTH TO
NORTHWEST FOR MOST OF TUESDAY...WL CONTINUE A MODERATE SWIM RISK
DESPITE HIGHER WAVE HEIGHTS. THE HIGHEST WAVES WILL LIKELY BE
AWAY FROM THE SHORE AND BEACHES. IF WINDS ARE EXPECTED TO HANG ON
TO A MORE NORTH DIRECTION WITH THE NEW FORECAST...THEN THE SWIM
RISK MAY BE ELEVATED TO HIGH AND A BEACH HAZARD STATEMENT WOULD BE
ISSUED.
&&
.PREV DISCUSSION... /ISSUED 355 PM CDT MON AUG 11 2014/
SHORT TERM...
TONIGHT...FORECAST CONFIDENCE MEDIUM.
THUNDERSTORMS DEVELOPED ALONG THE LAKE BREEZE CONVERGENCE OVER
EASTERN WI EARLY THIS AFTERNOON. THIS AREA OF STORMS ARE EXPANDING
BUT NOT MOVING...SO EXPECT AN INCH OF RAIN THERE THROUGH LATE
AFTERNOON.
MEANWHILE...VORTICITY ADVECTION WITHIN AN UPPER LEVEL TROUGH IS
DROPPING SOUTHEAST THROUGH WI THIS AFTERNOON. THE UPPER TROUGH WILL
CLOSE OFF AND STALL OVER SOUTHERN WI THIS EVENING. IT IS TAKING A
WHILE FOR CONVECTION TO DEVELOP ALONG THE COLD FRONT/ LEADING EDGE
OF VORT MAX/ OVER SOUTH CENTRAL WI...BUT THERE IS FINALLY A BROKEN
LINE DEVELOPING AT 230 PM NEAR MADISON AND THE DELLS THIS AFTERNOON.
I AM EXPECTING THIS LINE TO FILL AS IT GETS EAST OF MADISON AND
ESPECIALLY IN SOUTHEAST WI WHEN IT INTERACTS WITH THE LAKE BREEZE
BOUNDARY. THE HRRR MODEL SEEMS TO HAVE A GOOD HANDLE ON THIS.
PRECIPITABLE WATER VALUES ARE FAIRLY HIGH AROUND 1.5 INCHES. THE
UPPER LEVEL FLOW IS WEAK. THE SHEAR IS WEAK AND THERE IS 500 TO 1000
J/KG OF SURFACE BASED...TALL/SKINNY CAPE. THIS MEANS THE
THUNDERSTORMS WILL BE PULSY AND EFFICIENT RAIN PRODUCERS. WE CANNOT
RULE OUT SMALL HAIL WITH THE STRONGER STORMS...BUT THIS WILL BE THE
MINORITY. THE MAIN THREAT THIS AFTERNOON WILL BE PERIODS OF HEAVY
RAIN WHICH COULD CAUSE SOME URBAN FLOODING.
AFTER THE MAIN LINE OF STORMS MOVES THROUGH WITH THE
FRONT...CLEARING THE LAKESHORE AROUND 2-3Z...EXPECT ADDITIONAL
SHOWERS TO SPREAD BACK IN ACROSS SOUTH CENTRAL AND SOUTHEAST WI
DURING THE REST OF THE OVERNIGHT. THESE WILL BE ASSOCIATED WITH THE
UPPER TROUGH CLOSING OFF OVER THE WESTERN GREAT LAKES AND THE MAIN
VORTICITY MAX MOVING THROUGH SOUTHERN WI. THIS IS ALSO COINCIDENT
WITH UPPER DIVERGENCE IN THE LEFT EXIT REGION OF AN UPPER JET.
EXPECTING LOW CLOUDS TO SPREAD INTO SOUTHERN WI OVERNIGHT AS THE
RAIN SHOWERS RE-DEVELOP WITH THE UPPER LOW. THIS WILL KEEP TEMPS
WARMER...SO MIN TEMPS WILL BE AROUND 60 FOR MOST AREAS.
TUESDAY...FORECAST CONFIDENCE MEDIUM.
THE UPPER TROUGH DOES NOT SHIFT EAST UNTIL LATER TUESDAY MORNING.
LINGERED SMALL CHANCE OF RAIN SHOWERS OVER SOUTHEAST WI THROUGH
MIDDAY. THE CLOUDS WILL LINGER LONGER IN THE EAST AS WELL...SO KEPT
MAX TEMPS IN THE LOWER 70S THERE...AND MID 70S INLAND.
THE DRY AIR WILL GRADUALLY WORK ITS WAY INTO SOUTHERN WI MIDDAY
TUESDAY. THE MODELS ARE NOT IN AGREEMENT ABOUT EXACTLY WHEN THIS
WILL HAPPEN.
EXPECTING GUSTY NORTH-NORTHWEST WINDS TUESDAY MORNING AS THE SURFACE
PRESSURE GRADIENT INCREASES AS LOW PRESSURE STRENGTHENS OVER LOWER
MICHIGAN.
TUESDAY NIGHT THROUGH THURSDAY...FORECAST CONFIDENCE HIGH.
A LARGE POLAR TROUGH WILL RESIDE OVER FAR ERN ONTARIO AND WRN
QUEBEC CANADA THROUGH THURSDAY WITH NWLY FLOW ALOFT OVER WI. VERY
WEAK VORTICITY MAXIMUMS WILL LIKELY MOVE ACROSS THE AREA AND THE
MODELS DO DEPICT A VERY WEAK SFC TROUGH TO SHIFT SOUTH THROUGH THE
AREA WED AND WED NT. WEAK LOW LEVEL WARM ADVECTION IS EXPECTED
AHEAD OF THE TROUGH BUT THE COMBINATION OF A FAIRLY DRY AIRMASS
AND LITTLE TO NO LIFT SUPPORTS A DRY FCST. SCT-BKN MID LEVEL
CLOUDS ARE LIKELY WED AND WED NT BUT STILL ENOUGH SUNSHINE FOR
TEMPS TO WARM TO SEASONAL NORMALS ON WED. HIGH PRESSURE TO THEN
SETTLE OVER THE WRN GREAT LAKES FOR THU. DRY ENELY WINDS WILL
PREVAIL WITH PLEASANT TEMPS AND HUMIDITY.
LONG TERM...
FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM.
HIGH PRESSURE WILL MOVE EWD ON FRI WITH LGT SLY WINDS DEVELOPING.
HEAT AND HUMIDITY WILL INCREASE THROUGH THE WEEKEND INTO EARLY
NEXT WEEK AS A SHORTWAVE TROUGH AND SFC LOW APPROACHES. SLIGHT
CHANCES OF TSTORMS ARE FORECAST FOR THE WEEKEND WITH BETTER
CHANCES OF TSTORMS BY MONDAY.
AVIATION/00Z TAFS/...
A LINE OF SHOWERS AND THUNDERSTORMS IS DEVELOPING ALONG A COLD FRONT
IN SOUTH CENTRAL WISCONSIN AND WILL CONTINUE TO FILL IN AND EXPAND
AS IT TRACKS EASTWARD THROUGH SOUTHERN WI LATER THIS AFTERNOON INTO
THE EVENING. EXPECT MVFR CIGS/VSBYS WITH SHOWERS AND STORMS...WITH
SOME IFR VSBYS IN HEAVIER DOWNPOURS.
SHOWERS ARE EXPECTED TO RE-DEVELOP THIS EVENING AND LINGER THROUGH
TUESDAY MORNING AS THE SURFACE TROUGH/FRONT STALLS OVER SOUTHEAST
WI. THERE IS STILL UNCERTAINTY ABOUT HOW WIDESPREAD AND HOW FAR WEST
THESE WILL BE. EXPECT IFR STRATUS BEHIND COLD FRONT LATE TONIGHT AND
TUE MORNING AS WELL. LOOK FOR GUSTY NNW WINDS TUESDAY MORNING.
MARINE...
INCREASING NORTHERLY WINDS IN THE WAKE OF A COLD FRONT EARLY TUESDAY
MORNING WILL BUILD HIGH WAVES ON TUESDAY. A SMALL CRAFT ADVISORY
WAS ISSUED WITH THE 930 AM NSH UPDATE.
BEACHES...
A MODERATE TO HIGH SWIM RISK IS EXPECTED ON TUESDAY. GUSTY NORTHERLY
WINDS WILL BUILD HIGH WAVES DURING THE DAY TUESDAY. HIGHEST WAVES
WILL BE TOWARD THE OPEN WATERS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 7 AM TO 9 PM CDT TUESDAY FOR
LMZ644>646.
SMALL CRAFT ADVISORY FROM 4 AM TO 9 PM CDT TUESDAY FOR LMZ643.
&&
$$
UPDATE...MBK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
615 PM CDT MON AUG 11 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 233 PM CDT MON AUG 11 2014
LATEST WATER VAPOR SATELLITE IMAGERY SHOWING SHORTWAVE TROUGH
SPINNING ACROSS NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN. THE
11.12Z GFS/NAM AND 11.15Z RAP INDICATE DECENT FORCING IN ASSOCIATION
WITH SHORTWAVE TROUGH. THIS IS PRODUCING SHOWERS AND ISOLATED
THUNDERSTORMS MAINLY ACROSS EASTERN MINNESOTA AND MUCH OF
WISCONSIN PER LATEST MOSAIC RADAR.
MAIN CONCERNS TONIGHT ARE DIMINISHING TRENDS OF PRECIPITATION AND
LOW CLOUDS ACROSS THE FORECAST AREA. THE 11.12Z GFS/NAM INITIALIZE
SHORTWAVE TROUGH AND MOISTURE FIELDS WELL PER THE LATEST
VISIBLE/WATER VAPOR SATELLITE IMAGERY. THE 11.12Z GFS/NAM SHOW THE
FORCING TO EXIT THE FORECAST AREA AROUND 06Z TUESDAY AND ASSOCIATED
MOISTURE WITH SHORTWAVE TROUGH BY 12Z TUESDAY. HAVE TRENDED
PRECIPITATION CHANCES AND SKY COVER FOR THIS.
SURFACE RIDGE OVER THE DAKOTAS WILL BUILD INTO MINNESOTA AND
WESTERN WISCONSIN TUESDAY. SUBSIDENCE UNDERNEATH SURFACE HIGH WILL
ALLOW FOR DRY WEATHER CONDITIONS AND BELOW NORMAL TEMPERATURES
ACROSS THE FORECAST AREA.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 233 PM CDT MON AUG 11 2014
WITH SURFACE RIDGE OVERHEAD ACROSS FORECAST AREA...THE 11.12Z
NAM/GFS ARE INDICATING AN INVERSION TO DEVELOP AFTER 06Z WEDNESDAY
PER BUFKIT SOUNDINGS. DUE TO WINDS AROUND 5 KNOTS THROUGH 1500
FEET. EXPECT THE FORMATION OF FOG OVER CENTRAL WISCONSIN AND IN
RIVER VALLEYS WEDNESDAY MORNING.
WEDNESDAY...FORECAST AREA REMAINS UNDER NORTHWEST FLOW ALOFT. THE
11.12Z GFS/NAM SHOW WEAK IMPULSE EMBEDDED IN THE NORTHWEST FLOW
ALOFT TO MOVE OVER PARTS OF THE FORECAST AREA. BUFKIT SOUNDINGS FROM
THE 11.12Z GFS/NAM INDICATE STEEP LOW LEVEL LAPSE RATES AND SOME
INSTABILITY ALOFT DURING THE DAY ACROSS CENTRAL WISCONSIN. THE
11.12Z NAM MORE ROBUST WITH THE INSTABILITY AND LOW LEVEL LAPSE
RATES THAN THE GFS. CANNOT RULE OUT AN ISOLATED SHOWER OR
THUNDERSTORM ACROSS CENTRAL WISCONSIN WEDNESDAY AFTERNOON. FOR
NOW...WILL CONTINUE WITH MENTION OF SPRINKLES OVER THIS AREA.
THE COMBINATION OF THE MAIN AXIS OF ISENTROPIC LIFT WEST OF FORECAST
AREA AND SHORTWAVE RIDGING BUILDING INTO THE REGION THURSDAY...WILL
PROVIDE DRY WEATHER CONDITIONS ACROSS THE AREA. HAVE REMOVED SMALL
PRECIPITATION CHANCES OVER THE WESTERN FORECAST AREA.
MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES THURSDAY NIGHT INTO
MONDAY. THE 11.12Z GFS/GEM/ECMWF ARE IN GOOD AGREEMENT BREAKING DOWN
UPPER LEVEL TROUGH OVER THE EASTERN UNITED STATES THIS WEEKEND AND
DEVELOP WEST TO EAST ZONAL FLOW ACROSS THE CONTINENTAL UNITED
STATES. BIGGEST DIFFERENCE BETWEEN THE MODELS IS TIMING AND
PLACEMENT OF SHORTWAVE TROUGHS EMBEDDED IN THE WEST TO EAST ZONAL
FLOW SATURDAY INTO MONDAY. THE 11.12Z GFS/ECMWF INDICATE DECENT
MOISTURE TRANSPORT AND CONVERGENCE WITH SHORTWAVE TROUGH PUSHING
INTO THE UPPER MIDWEST AND GREAT LAKES REGION SUNDAY INTO MONDAY.
DEPENDING ON TIMING/PLACEMENT OF SURFACE FEATURES/SHORTWAVE
TROUGH...PRECIPITATION CHANCES LOOK REASONABLE ACROSS MUCH OF THE
FORECAST AREA SATURDAY INTO MONDAY. HOWEVER...CONFIDENCE IS LOW ON
THE EXACT TIMING AND PLACEMENT OF THE SURFACE FEATURES/SHORTWAVE
TROUGHS TRACKING INTO THE UPPER MIDWEST AND GREAT LAKES REGION
DURING THIS PERIOD. TEMPERATURES FRIDAY INTO EARLY NEXT WEEK WILL
BE NEAR OR SLIGHTLY BELOW NORMAL ACROSS FORECAST AREA...WITH HIGHS
GENERALLY AROUND 80 DEGREES INTO THE LOWER TO MIDDLE 80S
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 615 PM CDT MON AUG 11 2014
CLOUD STREAKS WORKING NORTH TO SOUTH ACROSS THE REGION...MOSTLY MVFR-
VFR...IN A REGION OF INSTABILITY AND ASSOCIATED WITH AN UPPER LEVEL
TROUGH. AREAS OF -SHRA ALSO BEING GENERATED. EXPECT THE PCPN TO
QUICKLY DIMINISH WITH THE LOSS OF DAYTIME HEATING...WITH A GRADUAL
DECREASE IN THE CLOUD COVER ALSO. THAT SAID...SOME SUGGESTION IN THE
NAM THAT LOW LEVEL MOISTURE WOULD HANG AROUND KLSE FOR MUCH OF
TONIGHT...RESULTING IN LOW LEVEL STRATUS. RAP/GFS DISAGREE. GOING
WITH THE CLEARING TREND FOR NOW. WINDS SHOULD STAY UP...CLOSE TO 10
KTS FOR THE NIGHTTIME HOURS. THIS SHOULD MINIMIZE ANY FOG THREAT.
EXPECT VFR CONDITIONS FOR TUE WITH LATE MORNING/AFTERNOON MIXING
RESULTING IN SOME HIGHER WIND GUSTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM....DTJ
AVIATION.....RIECK
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 228 PM CDT SUN AUG 10 2014
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE
HIGH PRESSURE STRETCHING FROM THE WESTERN GREAT LAKES TO NORTHEAST
NORTH AMERICA WHILE A COLD FRONT IS DROPPING SOUTHEAST OVER THE
NORTHERN GREAT PLAINS. A WEAK AREA OF LOW PRESSURE IS SPINNING OVER
CENTRAL MINNESOTA AHEAD OF THE FRONT...AND COMBINED WITH WEAK
SHORTWAVE ENERGY...IS PRODUCING SHOWERS FROM JUST WEST OF DULUTH TO
SOUTHWEST MINNESOTA. OTHER SPOTTIER SHOWERS ARE POPPING UP IN THE
MOISTURE RETURN OVER SOUTHERN AND CENTRAL LAKE MICHIGAN. MOST OF
THE MESO MODELS KEEP THESE LIGHT SPOTTY SHOWERS OR SPRINKLES
OFFSHORE OVER THE LAKE. BUT AS THE FRONT MOVES INTO THE REGION LATE
TONIGHT AND MONDAY...TIMING OF SHOWERS AND THUNDERSTORMS IS THE MAIN
FORECAST CONCERN.
TONIGHT...A SHORTWAVE TROUGH DROPPING SOUTHEAST OUT OF SOUTH-CENTRAL
CANADA WILL PUSH A COOL FRONT INTO NORTHWEST WISCONSIN LATE. AHEAD
OF THIS FRONT...LOW AND MID-LEVEL WINDS WILL SWING TO THE SOUTH AND
ADVECT MOISTURE FROM ILLINOIS AND INDIANA. A FEW SHOWERS FROM THIS
MOISTURE ARE PROJECTED TO REMAIN OVER THE LAKE. AMPLE CLOUD COVER
SHOULD ALSO ARRIVE WITH THE FRONT AS A WEAK AREA OF LOW PRESSURE
MOVES INTO CENTRAL WISCONSIN LATE. PROGGED SOUNDINGS INDICATE A
MID-LEVEL DRY WEDGE OVER CENTRAL AND NORTH-CENTRAL WISCONSIN ERODING
LATE TONIGHT WHEN A MID-LEVEL THETAE AXIS MOVES INTO THAT PART OF
THE STATE. WILL RAMP UP PRECIP CHANCES AFTER 09Z WHEN THE COLUMN
BECOMES MORE SATURATED AND FORCING MARGINALLY INCREASES.
OTHERWISE...SLOWED DOWN THE CHANCE OF PRECIP THIS EVENING DUE TO THE
PRESENCE OF DRY AIR. LOW TEMPS SHOULD BE SEVERAL DEGREES WARMER DUE
TO THE INCREASING CLOUD COVER...AND WENT WITH TEMPS RANGING FROM
THE UPPER 50S NORTH OT LOWER 60S SOUTH.
MONDAY...THE SHORTWAVE AND COLD FRONT WILL GRADUALLY MOVE ACROSS
WISCONSIN. WITH DAYTIME HEATING...THE SREF INCREASES PRECIP CHANCES
DRAMATICALLY IN THE 15Z-18Z PERIOD OVER CENTRAL AND NORTH-CENTRAL
WISCONSIN...AND THEN SPREAD THE HIGHER PRECIP CHANCES INTO NORTHEAST
WISCONSIN AFTER MIDDAY. THIS LOOKS REASONABLE. TOUGH TO GET AN
ESTIMATE ON POTENTIAL INSTABILITY SINCE PROGGED SOUNDINGS LOOK
CONVECTIVELY MODIFIED...BUT A ROUGH ESTIMATE IS BETWEEN 500-1000
J/KG OF ML CAPE. BUT 0-6KM BULK SHEARS ARE ONLY AROUND 25 KTS AND
THINK FORCING IS TOO WEAK TO GENERATE MUCH OF A SEVERE THREAT. A
FEW STORMS COULD PRODUCE GUSTY WINDS TO 40-50 MPH AND SMALL HAIL.
MOSTLY CLOUDY AND MORE HUMID WITH HIGHS NEAR 70 NORTH TO AROUND 80
SOUTH.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 228 PM CDT SUN AUG 10 2014
RATHER STABLE MEAN LONGWAVE PATTERN FOR MOST OF THE EXTENDED WITH
NOTABLE TROUGHS SITUATED ON BOTH COASTS AND RIDGE OVER THE
INTER-MOUNTAIN WEST EXTENDING INTO CANADA. THE WESTERN GREAT LAKES
WILL REMAIN UNDER THE INFLUENCE OF SURFACE HIGH PRESSURE BENEATH
NORTHWESTERLY FLOW ALOFT. PATTERN OFFERS LITTLE OPPORTUNITY FOR
SUBSTANTIAL RAINFALL FOR MOST OF THE WORK WEEK. SEASONABLY WARM
TEMPERATURES WITH COMFORTABLE DAYTIME HUMIDITIES...AND COOL NIGHTS
WILL BE THE RULE.
EARLY IN THE EXTENDED...DEEPENING UPPER TROUGH OVER THE GREAT
LAKES REGION MONDAY NIGHT WILL CONTINUE TO SWING EAST DURING THE
DAY ON TUESDAY. IN GENERAL...THE MODELS IN FAIRLY GOOD AGREEMENT
ON OVERALL TIMING OF BACK EDGE OF BROKEN BAND OF SHOWERS AND
ISOLATED THUNDERSTORMS MONDAY EVENING. USING A BLENDED MODEL QPF
SUGGESTS THAT PRECIPITATION SHOULD BE EAST OF THE FORECAST AREA BY
06Z TUESDAY.
IN THE WAKE OF THE DEPARTING SURFACE LOW SITUATED NEAR LAKE HURON
TUESDAY MORNING...EXPECT FAIRLY DECENT NORTHERLY BOUNDARY LAYER
FLOW TO PERSIST AT LEAST FOR THE FIRST HALF OF THE DAY OVER THE
FORECAST AREA. GRADIENT SHOULD RELAX DURING THE AFTERNOON WITH
DIMINISHING WIND AND CLEARING SKIES. WITH THE CLOUDY START...COLD
ADVECTION...AND CORE OF COOLEST 850 TEMPS IN THE 8 TO 10 DEGREE
CELSIUS RANGE OVER THE AREA...DAYTIME HIGHS WILL BE THE COOLEST OF
THE WEEK...MAINLY IN THE LOW TO MID 70S.
DAYTIME HIGHS SHOULD MODERATE QUICKLY WEDNESDAY WITH READINGS
AROUND NORMAL FOR MIDDLE OF AUGUST. WEAK COLD FRONT DROPPING SOUTH
DURING THE DAY ON WEDNESDAY MAY BRING A FEW MORE CLOUDS AND
PERHAPS A SPRINKLE SOMETIME DURING THE DAY. DO NOT EXPECT MUCH
MORE THAN THAT GIVEN PALTRY MOISTURE AND FORCING.
HIGH PRESSURE REMAINS IN CONTROL THURSDAY AND FRIDAY WITH NEAR
NORMAL TEMPERATURES.
LATEST GUIDANCE WOULD ALSO SUGGEST SATURDAY WILL REMAIN DRY WITH
HINTS OF A CONFLUENT UPPER-LEVEL FLOW AND SURFACE RIDGE AXIS
PERSISTING OVER THE AREA.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 100 PM CDT SUN AUG 10 2014
VFR CONDITIONS WILL CONTINUE THROUGH THE EVENING
HOURS...BUT WITH AFTERNOON CUMULUS AND MID-LEVEL CLOUDS GRADUALLY
INCREASING. A WEAK AREA OF LOW PRESSURE WILL BE MOVING INTO CENTRAL
WISCONSIN LATE TONIGHT...WHICH WILL PROMOTE LOWERING VSBYS DESPITE
BROKEN MID-LEVEL CLOUDS OVERHEAD. AS DEEPER MOISTURE AHEAD OF A
COLD FRONT ARRIVES LATE TONIGHT INTO MONDAY MORNING...A CHANCE OF
SHOWERS WILL SPREAD EAST ACROSS CENTRAL AND NORTH-CENTRAL
WISCONSIN. THE CHANCE OF SHOWERS WILL IMPROVE WITH DAYTIME HEATING
ALONG WITH LOWERING CIGS TO MVFR.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ESB
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
233 PM CDT SUN AUG 10 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 233 PM CDT SUN AUG 10 2014
MAIN SHORT TERM CONCERN IS ON PRECIPITATION CHANCES.
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE WESTERN U.S. INTO BRITISH COLUMBIA AND OVER
THE EASTERN GREAT LAKES...WHILE TROUGHING WAS DROPPING SOUTH THROUGH
SOUTH CENTRAL CANADA. TWO OTHER SHORTWAVE TROUGHS WERE EVIDENT OVER
NORTHERN MN AND SOUTHERN IOWA. BOTH OF THESE SHORTWAVE TROUGHS WERE
PRODUCING SHOWERS AND SOME THUNDERSTORMS...BUT SO FAR THEY HAVE
STAYED WEST OF THE FORECAST AREA. THIS IS DUE TO HIGH PRESSURE
REMAINING IN PLACE OVER THE GREAT LAKES...PROVIDING A FLOW OF DRY
AIR INTO THE REGION. GOES PRECIPITABLE WATER IMAGERY DEPICTED THE
DIFFERENCE IN MOISTURE WELL...RANGING FROM 1-1.25 INCHES OVER THE
FORECAST AREA TO 1.5-1.75 INCHES FROM NORTH CENTRAL MN INTO WESTERN
IOWA AND MISSOURI. THE DRIER AIRMASS OVER THE FORECAST AREA HAS LED
TO A MOSTLY SUNNY DAY...AMD WITH 850MB TEMPS OF 12-14C ON 12Z
RAOBS...TEMPERATURES HAVE CLIMBED INTO THE UPPER 70S/LOW 80S. IN THE
SEA LEVEL PRESSURE FIELD...MAIN ITEM TO NOTE IS A COLD FRONT
TRACKING ACROSS WESTERN MN AHEAD OF THE SOUTH CENTRAL CANADA UPPER
TROUGH. ANOTHER SIGNIFICANT DRY AIRMASS WAS COMING IN BEHIND IT WITH
PRECIPITABLE WATER VALUES OF 0.5-0.75 INCHES ACROSS NORTH DAKOTA.
OVER THE NEXT 24 HOURS...THE TROUGHING OVER SOUTH CENTRAL CANADA IS
PROGGED TO DROP THROUGH THE FORECAST AREA. AS THE TROUGHING
APPROACHES...THE STREAM OF HIGHER PRECIPITABLE WATER VALUES JUST OFF
TO OUR WEST WILL MOVE INTO THE FORECAST AREA...BRINGING THE
POTENTIAL FOR PRECIPITATION. HOWEVER...FORCING MECHANISMS FOR
PRECIPITATION ARE A BIT PROBLEMATIC. FOR TONIGHT...THAT SHORTWAVE
TROUGH OVER NORTHERN MN IS PROGGED TO PROGRESS TOWARDS LAKE
SUPERIOR...WHILE THE SHORTWAVE TROUGH OVER IOWA HEADS DOWN INTO
MISSOURI AND SOUTHERN ILLINOIS. THUS...THESE SHORTWAVES SPLIT AROUND
THE REGION. MODEL QPF PROGS REFLECT THIS WELL. PERHAPS SOME SHOWERS
TRAILING SOUTH OF THE NORTHERN MN SHORTWAVE...AIDED BY DAYTIME
HEATING...WILL MAKE IT INTO NORTHWEST SECTIONS OF THE FORECAST AREA.
THIS IS EVIDENT ON CURRENT RADAR IMAGERY. THUS...HAVE MAINTAINED
SOME LOW PRECIPITATION CHANCES.
HEADING INTO MONDAY...PRECIPITATION CHANCES LOOK A LITTLE
BETTER...PRIMARILY ACROSS WISCONSIN AS THE MAIN TROUGHING COMES
THROUGH AT PEAK HEATING. ITS INTERESTING TO NOTE THAT THE SURFACE
COLD FRONT SHOULD COME THROUGH TONIGHT...BUT THE MOISTURE REALLY
DOESNT GET SCOURED OUT UNTIL THE MAIN TROUGHING MOVES IN. WITH
GOOD MODEL AGREEMENT FOR SHOWERS AND STORMS TO FIRE ACROSS
WISCONSIN IN THE LATE MORNING AND AFTERNOON...HAVE KEPT
PRECIPITATION CHANCES UP IN THE 60-70 RANGE. ONE THING WE WILL
HAVE TO WATCH IS SOME OF THE 12Z HIRES MODELS...ARW/NMM/SPCWRF-
NMM...SUGGEST PRECIPITATION COULD INITIATE JUST EAST OF THE
FORECAST AREA AND STAY TO THE EAST. WEST OF THE MS RIVER...CLOUDS
THAT MOVE IN TONIGHT ARE LIKELY TO CLEAR AS THE LOWER PRECIPITABLE
WATER VALUES ADVECT IN.
NOT ANTICIPATING ANYTHING SEVERE WITH THE STORMS ON MONDAY. ALTHOUGH
EQUILIBRIUM LEVELS ARE UP NEAR 30000 FT...CAPE PROFILE OVERALL IS
QUITE SKINNY. 0-6KM SHEAR IS LESS THAN 25 KT AND WARM CLOUD DEPTHS
ARE AROUND 3500 M. IF ANYTHING...WE WILL HAVE A COUPLE OF HEAVY RAIN
PRODUCERS.
INCREASING CLOUDS AND HIGHER PRECIPITABLE WATER TONIGHT SHOULD
RESULT IN A WARMER NIGHT TONIGHT. COOLEST SPOT LIKELY TO BE IN
CENTRAL WI WHERE CLOUDS/MOISTURE ARRIVE LAST. CLOUDS WILL BE A BIT
OF AN ISSUE ON MONDAY FROM WARMING...BUT ENOUGH SUN SHOULD FILTER
THROUGH PLUS CLEARING WEST OF MS RIVER LATER IN THE DAY TO ALLOW FOR
HIGHS IN THE 70S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 233 PM CDT SUN AUG 10 2014
STRONG DRYING AND SUBSIDENCE ARE ON TRACK TO COME INTO THE FORECAST
AREA MONDAY EVENING...PUSHING ANY LINGERING PRECIPITATION QUICKLY
OFF TO THE EAST AND CAUSING SKIES TO CLEAR OUT. PRECIPITABLE WATER
VALUES FALLING TO 0.5-0.75 INCHES BY 12Z TUESDAY WOULD BE FAVORABLE
FOR A GOOD RADIATIONAL COOLING NIGHT...BUT A PERSISTENT NORTHWEST
BREEZE SHOULD HELP A BIT FROM ALLOWING TEMPERATURES TO COMPLETELY
TANK.
TUESDAY THROUGH WEDNESDAY FEATURES GRADUALLY RISING 500MB HEIGHTS AS
UPPER TROUGHING DEVELOPS OVER THE PACIFIC NORTHWEST...PUSHING THE
UPPER RIDGING THERE EASTWARD AND THE NEW TROUGHING OVER THE FORECAST
AREA EASTWARD. SUBSIDENCE FROM THESE RISING 500MB HEIGHTS SHOULD
HELP TO KEEP THE FORECAST AREA DRY. HOWEVER...LATE WEDNESDAY...BOTH
THE 10.12Z GFS AND NAM DEPICT SOME LIGHT QPF MOSTLY NORTH OF I-90.
10.12Z ECMWF HAS SOME ISOLATED LIGHT QPF...MOSTLY NORTH OF I-90.
10.12Z CANADIAN ALSO DEPICTS SOME LIGHT QPF BUT SOUTH OF I-90. THIS
QPF IS A RESULT OF A WARM ADVECTION PATTERN DEVELOPING...WITH
ISENTROPIC LIFT/800-700MB MOISTURE TRANSPORT INITIATING PRECIPITABLE
BELOW THE 500MB SUBSIDENCE. CONCERNED THE GFS/NAM MAY BE OVERLY
WET...ESPECIALLY THE GFS...BUT WITH THE SIGNAL THERE HAVE INCLUDED A
MENTION OF SPRINKLES ALONG/NORTH OF I-90. TEMPERATURES TUESDAY
SHOULD BOUNCE WELL INTO THE 70S...FOLLOWED BY GOOD RADIATIONAL
COOLING AT NIGHT AS A SURFACE RIDGE SETTLES IN. COULD SEE SOME
VALLEY/RADIATIONAL FOG EARLY WEDNESDAY MORNING AS WELL. SLIGHTLY
WARMER 850MB TEMPS ON WEDNESDAY COMBINED WITH MORNING SUN SHOULD
HELP GIVE A COUPLE DEGREE BOOST TO HIGHS COMPARED TO TUESDAY.
IN THE EXTENDED RANGE...GOOD MODEL AGREEMENT EXISTS OF THE PACIFIC
NORTHWEST TROUGH LIFTING OUT AND TRACKING EAST...ALLOWING THE UPPER
RIDGE DOWNSTREAM EVENTUALLY TO MOVE OVER THE FORECAST AREA FOR THE
WEEKEND. THIS 500MB FLOW PATTERN SUGGESTS PERSISTENT WARM ADVECTION.
09.12Z/10.00Z ECMWF AND 10.12Z GFS IN FACT SUGGEST A BRIEF SURGE OF
HEAT TO COME INTO THE AREA ON SUNDAY. HOWEVER...THE NEW 10.12Z HAS
COMPLETELY WENT AWAY FROM THIS...DUE TO A SHORTWAVE TROUGH DIGGING
SOUTH THROUGH THE PLAINS WHICH BLOCKS THE HEAT FROM ARRIVING ON
SUNDAY. MOST DAYS WE SHOULD SEE HIGHS IN THE UPPER 70S TO PERHAPS AT
MOST MID 80S. ON THE PRECIPITATION SIDE OF THINGS...ITS POSSIBLE
THAT MID-LEVEL SHOWER/SPRINKLE STUFF FROM WEDNESDAY AFTERNOON
PERSISTS THROUGH FRIDAY. THE LOCATION LOOKS TO SHIFT TO MOSTLY WEST
OF THE MS RIVER AND MAY HAVE A FEW MORE SHOWERS WITH IT.
THEREFORE...DO HAVE SOME 20-30 PERCENT CHANCES. FRIDAY NIGHT THROUGH
THE WEEKEND IS NOW UP IN THE AIR AFTER THE 10.12Z ECMWF CAME IN.
PREVIOUSLY IT APPEARED A BETTER SHOT FOR SHOWERS AND STORMS WOULD
COME FRIDAY NIGHT AND SATURDAY AHEAD OF THE HEAT SURGE...AND AGAIN
LATE SUNDAY AS THE PACIFIC NORTHWEST TROUGH APPROACHED. HOWEVER...
THE NEW ECMWF HAS THE ENTIRE REGION UNDER HIGH PRESSURE AND DRY
CONDITIONS. HAVE SPLIT THE DIFFERENCE FOR NOW WHICH RESULTS IN 20-40
PERCENT CHANCES...MAYBE A 50 THERE ON SUNDAY. IF THE ECMWF IS RIGHT
WITH THIS SHORTWAVE DIVING THROUGH THE PLAINS...THE WEEKEND WILL
NEED TO BE DRIED OUT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1241 PM CDT SUN AUG 10 2014
AS OF EARLY AFTERNOON...A WEAK COOL FRONT STRETCHES FROM NORTH
CENTRAL MINNESOTA...TO NEAR SIOUX FALLS...DOWN INTO NORTHERN
NEBRASKA. THIS WILL SLIDE EAST TODAY...REACHING KRST/KLSE TONIGHT.
THE SHOWERS/STORMS ASSOCIATED WITH THE FRONT ARE DIURNAL...SO NOT
EXPECTING MUCH COVERAGE AS IT APPROACHES THE TERMINALS TONIGHT
THOUGH WILL CONTINUE THE VCSH GROUP AT KRST FOR THIS EVENING.
BEHIND THE FRONT...LOW LEVEL MOISTURE BECOMES TRAPPED UNDER A WEAK
INVERSION AND COUPLED WITH NIGHTTIME COOLING...A MVFR STRATUS IS
EXPECTED TO REDEVELOP OVER THE TAF SITES AFTER MIDNIGHT. CEILINGS
ARE LIKELY TO BE 1500 TO 2500 FT. THIS IS SEEN ALSO BY THE HI-RES
MODELS DEPICTION OF CEILINGS THROUGH THE PERIOD. IFR CEILINGS ARE
POSSIBLE AT KRST...THOUGH CONFIDENCE IS NOT HIGH ENOUGH NOW TO
INCLUDE. THE STRATUS SHOULD LINGER THROUGH THE MORNING
HOURS...MOVING EAST AND ALSO LIFTING AS DAYTIME MIXING KICKS IN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....ZT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1241 PM CDT SUN AUG 10 2014
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 253 AM CDT SUN AUG 10 2014
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TODAY THROUGH
MONDAY.
REGIONAL RADARS SHOW A WEAKENING AREA OF CONVECTION ACROSS
CENTRAL MINNESOTA THAT IS MOVING NORTHEAST. SEVERAL OF THE SHORT
TERM MESO MODELS HAVE A GOOD HANDLE ON THIS FEATURE WITH THE
10.05Z HRRR AND 10.00Z HI-RES ARW INDICATING THE WEAKENING TREND
WILL CONTINUE AS IT MOVES TOWARD NORTHWEST WISCONSIN. THIS WOULD
TAKE WHAT REMAINS OF THIS RAIN PAST THE FORECAST AREA TO THE
NORTHWEST AND PLAN TO STAY WITH A DRY MORNING.
HOW THE AFTERNOON PLAYS OUT IS LESS CLEAR. A WEAK TROUGH WILL BE
APPROACHING FROM THE NORTHWEST WITH THE SHORT WAVE TROUGH
RESPONSIBLE FOR THE ONGOING MINNESOTA CONVECTION HEADING TOWARD
LAKE SUPERIOR WHILE THE SHORT WAVE TROUGH DRIVING THE NEBRASKA
CONVECTION CONTINUES TO MOVE SOUTHEAST TOWARD MISSOURI. THIS
RESULTS IN THE AREA GETTING SPLIT BY THE SHORT WAVE TROUGH WITH
VERY LITTLE FORCING. THE LOW LEVEL RIDGE THAT HAS BEEN PARKED
OVER THE GREAT LAKES THE LAST FEW DAYS HAS KEPT THE DEEPER
MOISTURE AXIS SOUTH AND WEST OF THE FORECAST AREA AND THE 10.00Z
NAM SUGGESTS THAT WHILE THIS WILL SHIFT SLOWLY EAST...THE BEST
MOISTURE WILL REMAIN JUST OFF TO THE WEST OF THE AREA. THERE
SHOULD BE A DIURNAL INCREASE IN THE ACTIVITY THIS AFTERNOON AS THE
CAPE BUILDS AND THE QUESTION BECOMES WHETHER ANY OF THIS ACTIVITY
WILL DRIFT INTO THE WESTERN SECTIONS. THE HI-RES ARW...10.00Z HI-
RES NMM...10.06Z RAP AND 10.00Z ECMWF ALL INDICATE THE ACTIVITY
WILL REMAIN TO THE WEST OF THE AREA WHILE THE 10.00Z NAM AND GFS
TRY TO BRING SOME ACTIVITY INTO THE WESTERN SECTIONS. TEND TO
THINK THE MESO SCALE MODELS HAVE THE BETTER SOLUTIONS AND HAVE CUT
THE RAIN CHANCES BACK FOR THIS AFTERNOON TO PRIMARILY JUST WEST OF
THE MISSISSIPPI RIVER WITH A 20 TO 30 PERCENT CHANCE MAINLY AFTER
21Z.
THE INITIAL TWO SHORT WAVE TROUGHS WILL SLIDE PAST THE AREA
TONIGHT AS ANOTHER WAVE DROPS OUT OF CENTRAL CANADA. HOWEVER...THE
TIMING OF THIS WAVE LOOKS TO KEEP THE BULK OF ITS FORCING ACROSS
NORTHERN AND CENTRAL MINNESOTA INTO NORTHWESTERN WISCONSIN WHERE
THE NAM AND GFS INDICATE WEAK TO MODERATE PV ADVECTION IN THE
500-300 MB LAYER SHOULD OCCUR. THIS WAVE SHOULD PUSH A WEAK COLD
FRONT TOWARD THE AREA WITH ONLY SOME VERY WEAK FRONTOGENESIS
EXPECTED TO OCCUR IN THE 1000-700 MB LAYER. A LITTLE BIT OF
ISENTROPIC UP GLIDE SHOULD OCCUR CLOSE TO THE WAVE WITH THE NAM
SHOWING 1 TO 2 UBAR/S ACROSS NORTHERN WISCONSIN ON THE 300K
SURFACE. WITH THE BULK OF THE FORCING LOOKING TO BE COMING IN FROM
THE NORTH...WILL SHOW THE HIGHEST RAIN CHANCES TONIGHT IN THAT
AREA WITH ABOUT A 40 PERCENT CHANCE.
THIS SHORT WAVE TROUGH LOOKS TO ADVANCE QUICKLY SOUTHEAST TAKING
THE WEAK TO MODERATE PV ADVECTION ACROSS CENTRAL AND EASTERN
WISCONSIN MONDAY. AS THE WEAK COLD FRONT COMES THROUGH...THE WEAK
FRONTOGENESIS SHOULD MAINTAIN ITSELF BUT THE ISENTROPIC UP GLIDE
QUICKLY SLIDES OFF TO THE EAST. THE ML CAPE WILL INCREASE TO ABOUT
750 J/KG ALONG AND AHEAD OF THE FRONT. THIS SHOULD ALLOW FOR AN
INCREASE IN THE COVERAGE OF THE CONVECTION EAST OF THE MISSISSIPPI
RIVER BUT GIVEN THE WEAK FORCING...CONCERNED THE ACTIVITY MAY BE
MORE OF THE SCATTERED NATURE. HOWEVER...AT THIS TIME...WILL NOT
BACK OUT OF THE 60 PERCENT POPS ACROSS THE NORTHERN AND EASTERN
SECTIONS. GIVEN THE INCREASE IN THE SPEED OF THE WAVE ALL THE
MODELS ARE SHOWING...THE RAIN CHANCES COULD QUICKLY END LATE
MONDAY AFTERNOON AND IT MAY NOT BE NECESSARY TO CONTINUE THESE
INTO MONDAY EVENING AND THIS ADJUSTMENT MAY BE NEEDED IF LATER
MODEL RUNS CONTINUE TO SHOW THE QUICK EXIT OF THE RAIN.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 253 AM CDT SUN AUG 10 2014
ONCE THE EARLY WEEK SYSTEM MOVES PAST THE AREA...THE BUILDING
UPPER LEVEL RIDGE ACROSS THE WESTERN PART OF THE COUNTRY WILL MOVE
SLOWLY EAST TOWARD THE AREA. THE 10.00Z MODELS ARE CONTINUING TO
SHOW A SHORT WAVE TROUGH MOVING ACROSS THE AREA THURSDAY WITH
ANOTHER FOR FRIDAY. UNLIKE PREVIOUS RUNS WHICH FLATTENED THE RIDGE
TO ALLOW THESE WAVES TO COME THROUGH...THE CURRENT MODELS MAINTAIN
THE RIDGE AXIS TO THE WEST AND NOW SHOW THESE WAVES COMING
THROUGH MUCH WEAKER IN THE NORTHWEST FLOW. CURRENT INDICATIONS ARE
THAT THE FORCING WILL MAINLY AFFECT THE WESTERN PORTIONS OF THE
AREA AND ADJUSTED THE MODEL CONSENSUS GRIDS TO SHOW A DRIER
OUTCOME ACROSS THE NORTHERN AND EASTERN SECTIONS FOR THURSDAY
NIGHT THROUGH FRIDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1241 PM CDT SUN AUG 10 2014
AS OF EARLY AFTERNOON...A WEAK COOL FRONT STRETCHES FROM NORTH
CENTRAL MINNESOTA...TO NEAR SIOUX FALLS...DOWN INTO NORTHERN
NEBRASKA. THIS WILL SLIDE EAST TODAY...REACHING KRST/KLSE TONIGHT.
THE SHOWERS/STORMS ASSOCIATED WITH THE FRONT ARE DIURNAL...SO NOT
EXPECTING MUCH COVERAGE AS IT APPROACHES THE TERMINALS TONIGHT
THOUGH WILL CONTINUE THE VCSH GROUP AT KRST FOR THIS EVENING.
BEHIND THE FRONT...LOW LEVEL MOISTURE BECOMES TRAPPED UNDER A WEAK
INVERSION AND COUPLED WITH NIGHTTIME COOLING...A MVFR STRATUS IS
EXPECTED TO REDEVELOP OVER THE TAF SITES AFTER MIDNIGHT. CEILINGS
ARE LIKELY TO BE 1500 TO 2500 FT. THIS IS SEEN ALSO BY THE HI-RES
MODELS DEPICTION OF CEILINGS THROUGH THE PERIOD. IFR CEILINGS ARE
POSSIBLE AT KRST...THOUGH CONFIDENCE IS NOT HIGH ENOUGH NOW TO
INCLUDE. THE STRATUS SHOULD LINGER THROUGH THE MORNING
HOURS...MOVING EAST AND ALSO LIFTING AS DAYTIME MIXING KICKS IN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM....04
AVIATION.....ZT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
253 AM CDT SUN AUG 10 2014
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 253 AM CDT SUN AUG 10 2014
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TODAY THROUGH
MONDAY.
REGIONAL RADARS SHOW A WEAKENING AREA OF CONVECTION ACROSS
CENTRAL MINNESOTA THAT IS MOVING NORTHEAST. SEVERAL OF THE SHORT
TERM MESO MODELS HAVE A GOOD HANDLE ON THIS FEATURE WITH THE
10.05Z HRRR AND 10.00Z HI-RES ARW INDICATING THE WEAKENING TREND
WILL CONTINUE AS IT MOVES TOWARD NORTHWEST WISCONSIN. THIS WOULD
TAKE WHAT REMAINS OF THIS RAIN PAST THE FORECAST AREA TO THE
NORTHWEST AND PLAN TO STAY WITH A DRY MORNING.
HOW THE AFTERNOON PLAYS OUT IS LESS CLEAR. A WEAK TROUGH WILL BE
APPROACHING FROM THE NORTHWEST WITH THE SHORT WAVE TROUGH
RESPONSIBLE FOR THE ONGOING MINNESOTA CONVECTION HEADING TOWARD
LAKE SUPERIOR WHILE THE SHORT WAVE TROUGH DRIVING THE NEBRASKA
CONVECTION CONTINUES TO MOVE SOUTHEAST TOWARD MISSOURI. THIS
RESULTS IN THE AREA GETTING SPLIT BY THE SHORT WAVE TROUGH WITH
VERY LITTLE FORCING. THE LOW LEVEL RIDGE THAT HAS BEEN PARKED
OVER THE GREAT LAKES THE LAST FEW DAYS HAS KEPT THE DEEPER
MOISTURE AXIS SOUTH AND WEST OF THE FORECAST AREA AND THE 10.00Z
NAM SUGGESTS THAT WHILE THIS WILL SHIFT SLOWLY EAST...THE BEST
MOISTURE WILL REMAIN JUST OFF TO THE WEST OF THE AREA. THERE
SHOULD BE A DIURNAL INCREASE IN THE ACTIVITY THIS AFTERNOON AS THE
CAPE BUILDS AND THE QUESTION BECOMES WHETHER ANY OF THIS ACTIVITY
WILL DRIFT INTO THE WESTERN SECTIONS. THE HI-RES ARW...10.00Z HI-
RES NMM...10.06Z RAP AND 10.00Z ECMWF ALL INDICATE THE ACTIVITY
WILL REMAIN TO THE WEST OF THE AREA WHILE THE 10.00Z NAM AND GFS
TRY TO BRING SOME ACTIVITY INTO THE WESTERN SECTIONS. TEND TO
THINK THE MESO SCALE MODELS HAVE THE BETTER SOLUTIONS AND HAVE CUT
THE RAIN CHANCES BACK FOR THIS AFTERNOON TO PRIMARILY JUST WEST OF
THE MISSISSIPPI RIVER WITH A 20 TO 30 PERCENT CHANCE MAINLY AFTER
21Z.
THE INITIAL TWO SHORT WAVE TROUGHS WILL SLIDE PAST THE AREA
TONIGHT AS ANOTHER WAVE DROPS OUT OF CENTRAL CANADA. HOWEVER...THE
TIMING OF THIS WAVE LOOKS TO KEEP THE BULK OF ITS FORCING ACROSS
NORTHERN AND CENTRAL MINNESOTA INTO NORTHWESTERN WISCONSIN WHERE
THE NAM AND GFS INDICATE WEAK TO MODERATE PV ADVECTION IN THE
500-300 MB LAYER SHOULD OCCUR. THIS WAVE SHOULD PUSH A WEAK COLD
FRONT TOWARD THE AREA WITH ONLY SOME VERY WEAK FRONTOGENESIS
EXPECTED TO OCCUR IN THE 1000-700 MB LAYER. A LITTLE BIT OF
ISENTROPIC UP GLIDE SHOULD OCCUR CLOSE TO THE WAVE WITH THE NAM
SHOWING 1 TO 2 UBAR/S ACROSS NORTHERN WISCONSIN ON THE 300K
SURFACE. WITH THE BULK OF THE FORCING LOOKING TO BE COMING IN FROM
THE NORTH...WILL SHOW THE HIGHEST RAIN CHANCES TONIGHT IN THAT
AREA WITH ABOUT A 40 PERCENT CHANCE.
THIS SHORT WAVE TROUGH LOOKS TO ADVANCE QUICKLY SOUTHEAST TAKING
THE WEAK TO MODERATE PV ADVECTION ACROSS CENTRAL AND EASTERN
WISCONSIN MONDAY. AS THE WEAK COLD FRONT COMES THROUGH...THE WEAK
FRONTOGENESIS SHOULD MAINTAIN ITSELF BUT THE ISENTROPIC UP GLIDE
QUICKLY SLIDES OFF TO THE EAST. THE ML CAPE WILL INCREASE TO ABOUT
750 J/KG ALONG AND AHEAD OF THE FRONT. THIS SHOULD ALLOW FOR AN
INCREASE IN THE COVERAGE OF THE CONVECTION EAST OF THE MISSISSIPPI
RIVER BUT GIVEN THE WEAK FORCING...CONCERNED THE ACTIVITY MAY BE
MORE OF THE SCATTERED NATURE. HOWEVER...AT THIS TIME...WILL NOT
BACK OUT OF THE 60 PERCENT POPS ACROSS THE NORTHERN AND EASTERN
SECTIONS. GIVEN THE INCREASE IN THE SPEED OF THE WAVE ALL THE
MODELS ARE SHOWING...THE RAIN CHANCES COULD QUICKLY END LATE
MONDAY AFTERNOON AND IT MAY NOT BE NECESSARY TO CONTINUE THESE
INTO MONDAY EVENING AND THIS ADJUSTMENT MAY BE NEEDED IF LATER
MODEL RUNS CONTINUE TO SHOW THE QUICK EXIT OF THE RAIN.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 253 AM CDT SUN AUG 10 2014
ONCE THE EARLY WEEK SYSTEM MOVES PAST THE AREA...THE BUILDING
UPPER LEVEL RIDGE ACROSS THE WESTERN PART OF THE COUNTRY WILL MOVE
SLOWLY EAST TOWARD THE AREA. THE 10.00Z MODELS ARE CONTINUING TO
SHOW A SHORT WAVE TROUGH MOVING ACROSS THE AREA THURSDAY WITH
ANOTHER FOR FRIDAY. UNLIKE PREVIOUS RUNS WHICH FLATTENED THE RIDGE
TO ALLOW THESE WAVES TO COME THROUGH...THE CURRENT MODELS MAINTAIN
THE RIDGE AXIS TO THE WEST AND NOW SHOW THESE WAVES COMING
THROUGH MUCH WEAKER IN THE NORTHWEST FLOW. CURRENT INDICATIONS ARE
THAT THE FORCING WILL MAINLY AFFECT THE WESTERN PORTIONS OF THE
AREA AND ADJUSTED THE MODEL CONSENSUS GRIDS TO SHOW A DRIER
OUTCOME ACROSS THE NORTHERN AND EASTERN SECTIONS FOR THURSDAY
NIGHT THROUGH FRIDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY EVENING)
ISSUED AT 1004 PM CDT SAT AUG 9 2014
HIGH PRESSURE REMAINS STUCK OVER MICHIGAN WITH DRY EASTERLY FLOW
HELPING TO KEEP CONDITIONS VFR. EXPECT THIS PATTERN TO NOT CHANGE
MUCH OVER THE NEXT 24 HOURS...THUS THE FORECAST MAINTAINS MOSTLY
VFR CONDITIONS. THERE REMAINS TWO CONCERNS...THOUGH. THE FIRST IS
POTENTIAL FOR VALLEY FOG AND STRATUS AT LSE IN THE MORNING. A
LIGHT EASTERLY WIND AT THE GROUND IS FAVORABLE. HOWEVER...10 TO
20 KT WINDS ARE MODELED JUST ABOVE THE GROUND UNTIL 12Z...COMBINED
WITH THE LACK OF RECENT RAINFALL AND SCATTERED ALTOSTRATUS AROUND
YIELDS LOW CONFIDENCE OF THIS OCCURRING. ADDITIONALLY...THE
TEMPERATURE/DEWPOINT SPREADS ARE JUST MARGINAL. THEREFORE...HAVE
MAINTAINED THE BCFG AND SCT LIFR DECK FOR NOW. THE SECOND CONCERN
IS SUNDAY EVENING WHERE THERE IS A LOW CHANCE FOR A SHOWER OR
STORM TO MOVE INTO RST FROM THE WEST. GIVEN THE LOW CHANCE AND THE
EASTERLY DRY FLOW...HAVE KEPT PRECIPITATION OUT OF THE TAF FOR NOW.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...AJ
AREA FORECAST DISCUSSION...CORRECTED
NWS CHEYENNE WY
340 PM MDT SUN AUG 10 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 330 PM MDT SUN AUG 10 2014
THE AFTERNOON WATER VAPOR LOOP DEPICTED THE SHORTWAVE TROUGH THAT
BROUGHT YESTERDAY/S CONVECTION APPROACHING UPPER MS VALLEY. A
FAIRLY INTENSE CLOSED LOW WAS DRIFTING WEST OFF THE NORTHERN CA
COAST. IN BETWEEN THESE FEATURES WAS A BROAD RIDGE FROM THE GULF
COAST TO THE PACIFIC NORTHWEST. NORTHWEST FLOW AND SUBSIDENCE ALOFT
IN THE WAKE OF THE TROUGH HAS KEPT CONVECTION RATHER ISOLATED AND
CONFINED TO THE SNOWY/SIERRA MADRE RANGES. SOME RESIDUAL MOISTURE
AND INSTABILITY ASSOCIATED WITH A WEAK SOUTHWARD MOVING BOUNDARY
TRIGGERED ISOLATED CONVECTION OVER PORTIONS OF WESTERN NE. SKIES
WERE PARTLY TO MOSTLY SUNNY WITH TEMPERATURES IN THE 60S AND 70S.
PREVAILING WINDS WERE NORTHERLY AROUND 10 MPH...OCCASIONALLY GUSTING
TO 20 MPH IN A FEW LOCALES.
THE 12Z SHORT RANGE MODEL CONSENSUS APPROACH IS PREFERRED. SHORTWAVE
ENERGY DROPPING SOUTH FROM CANADA CARVES OUT A MERIDIONAL TROUGH
OVER THE GREAT LAKES/MIDWEST MONDAY. THE RIDGE AMPLIFIES OVER THE
CONTINENTAL DIVIDE AND SHIFTS EAST TOWARD THE FRONT RANGE TUESDAY
AS THE UPPER LOW DRIFTS INLAND AND OPENS OVER NORTHERN CA.
ISOLATED MOUNTAIN CONVECTION WILL DISSIPATE EARLY THIS EVENING WITH
THE LOSS OF ISOLATION. SKIES WILL BECOME MOSTLY CLEAR LATER THIS
EVENING. MONDAY WILL BE CARBON COPY OF TODAY WITH ISOLATED AFTERNOON
CONVECTION CONFINED TO THE HIGHER TERRAIN. A FEW OF THE SHOWERS OR
TSTORMS COULD DRIFT EAST TO THE I-25 CORRIDOR LATE IN THE AFTERNOON
BEFORE ENDING EARLY EVENING. WITH THE RIDGE AXIS NEAR THE FRONT RANGE
TUESDAY... SOME MONSOONAL MOISTURE WILL BEGIN TO WORK ITS WAY
NORTHWARD FROM WESTERN CO INTO SOUTH CENTRAL WY. THIS WILL RESULT
IN SLIGHTLY BETTER COVERAGE OF AFTERNOON AND EVENING CONVECTION ALONG
AND WEST OF THE LARAMIE RANGE. WITH A RELATIVELY WEAK SURFACE
PRESSURE GRADIENT...WIND SPEEDS WILL AVERAGE LESS THAN 15 MPH.
700MB TEMPERATURES MONDAY AFTERNOON WILL RANGE FROM 10 TO 13C YIELDING
HIGHS IN THE 80S TO NEAR 90 LOWER ELEVATIONS WITH 60S AND 70S MOUNTAINS.
TUESDAY/S HIGHS WILL BE ABOUT 5 DEGREES WARMER THAN MONDAY AS 700MB
TEMPERATURES CLIMB TO 12 TO 15C. LOWS IN THE 40S AND 50S TONIGHT AND
MONDAY NIGHT WILL WARM TO THE 50S TO LOWER 60S TUESDAY NIGHT.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 206 PM MDT SUN AUG 10 2014
MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT WITH THE OVERALL PATTERN
THROUGH THE PERIOD. BOTH THE ECMWF AND GFS SHOW STRONG UPPER-LEVEL
RIDGING OVER THE CENTRAL ROCKIES AND HIGH PLAINS ON WED IN ADVANCE
OF A VIGOROUS SHORTWAVE OVER THE PACIFIC NW. WHILE THIS WAVE SHOULD
PASS TO OUR NORTH LATER IN THE WEEK...SEVERAL ASSOCIATED PIECES OF
ENERGY WILL LIFT NORTHEAST ACROSS CO/WY ON WED AND THU. THIS OCCURS
IN LINE WITH ANOTHER SHOT OF MONSOON MOISTURE ON THE BACK SIDE OF
THE SUBTROPICAL RIDGE OVER THE SOUTHERN PLAINS...SO CONFIDENCE WAS
HIGH ENOUGH TO RAISE POPS INTO THE CHANCE CATEGORY FOR A FEW AREAS
DURING THAT TIME FRAME. THE GFS SUGGESTS PERSISTENT LEE TROUGHING
OVER THE PLAINS WILL KEEP LLVL MOISTURE INTACT OVER THE PANHANDLE
WITH DEW POINTS IN THE MID 50S. CAPES AROUND 500 TO 1000 J/KG EACH
AFTERNOON COULD AID IN STRONG STORMS...BUT SHEAR WILL GENERALLY BE
TOO WEAK BENEATH LARGER SCALE RIDGING TO SUPPORT ANYTHING MORE THAN
THE PULSE VARIETY. AFOREMENTIONED SHORTWAVE MOVES ACROSS THE NORTHERN
PLAINS OVER THE WEEKEND...PUSHING THE SFC TROUGH EAST OF THE CWA AND
USHERING IN SUFFICIENTLY DRY AIR TO REDUCE PCPN CHANCES. TEMPS THRU
THE PERIOD WILL BE SEASONAL BENEATH QUASI-ZONAL FLOW ALOFT OR MODEST
RIDGING. EXPECT LITTLE CHANGE IN HIGHS FROM DAY TO DAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY MORNING)
ISSUED AT 1138 AM MDT SUN AUG 10 2014
LOOK FOR SCT-TO-BKN COVERAGE OF CUMULUS ACROSS THE AREA AFTER 18Z
WITH ISOLATED SHOWERS AND THUNDERSTORMS OVER THE HIGHER TERRAIN.
THE HRRR MODEL SHOWS ISOLATED AFTERNOON CONVECTION ALONG AND WEST
OF THE LARAMIE RANGE...SO INTRODUCED VCTS INTO THE RWL AND LAR TAFS.
LINGERING MOISTURE COULD ALSO GIVE WAY TO A SHOWER OR STORM IN THE
NORTHERN PANHANDLE AFTER 20Z. BRIEF MVFR CONDITIONS OR ERRATIC WINDS
COULD OCCUR IF STORMS AFFECT ANY OF THE TERMINALS.
&&
.FIRE WEATHER...
ISSUED AT 241 PM MDT SUN AUG 10 2014
GENERALLY DRY CONDITIONS WILL PREVAIL THROUGH TUESDAY...EXCEPT FOR
ISOLATED AFTERNOON SHOWERS AND THUNDERSTORMS OVER AND NEAR THE
MOUNTAINS. MINIMUM RELATIVE HUMIDITIES WILL DROP TO NEAR CRITICAL
VALUES OVER NORTH AND WEST CARBON COUNTY MONDAY AND TUESDAY
AFTERNOONS. WINDS FOR THE MOST PART WILL AVERAGE 10 MPH OR LESS...
EXCEPT VARIABLE AND GUSTY IN THE VICINITY OF SHOWERS AND THUNDERSTORMS.
INCREASING MONSOONAL MOISTURE AND A FEW UPPER LEVEL DISTURBANCES
WILL RESULT IN SCATTERED SHOWERS AND THUNDERSTORMS WEDNESDAY AND
THURSDAY. SHOWER COVERAGE DECREASES LATE IN THE WEEK AS THE UPPER
RIDGE BUILDS OVER THE DISTRICTS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...JAMSKI
LONG TERM...HAMMER
AVIATION...HAMMER
FIRE WEATHER...JAMSKI
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
330 PM MDT SUN AUG 10 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 330 PM MDT SUN AUG 10 2014
THE AFTERNOON WATER VAPOR LOOP DEPICTED THE SHORTWAVE TROUGH THAT
BROUGHT YESTERDAY/S CONVECTION MOVING THROUGH THE UPPER MIDWEST. A
FAIRLY INTENSE CLOSED LOW WAS DRIFTING WEST OFF THE NORTHERN CA
COAST. IN BETWEEN THESE FEATURES WAS A BROAD RIDGE FROM THE GULF
COAST TO THE PACIFIC NORTHWEST. NORTHWEST FLOW AND SUBSIDENCE
ALOFT IN THE WAKE OF THE TROUGH HAS KEPT CONVECTION RATHER ISOLATED
AND CONFINED TO THE SNOWY/SIERRA MADRE RANGES. SOME RESIDUAL
MOISTURE AND INSTABILITY ASSOCIATED WITH A WEAK SOUTHWARD MOVING
BOUNDARY TRIGGERED ISOLATED CONVECTION OVER PORTIONS OF WESTERN
NE. SKIES WERE PARTLY TO MOSTLY SUNNY WITH TEMPERATURES IN THE 60S
AND 70S. PREVAILING WINDS WERE NORTHERLY AROUND 10 MPH...OCCASIONALLY
GUSTING TO 20 MPH IN A FEW LOCALES.
THE 12Z SHORT RANGE MODEL CONSENSUS APPROACH IS PREFERRED. SHORTWAVE
ENERGY DROPPING SOUTH FROM CANADA CARVES OUT A MERIDIONAL TROUGH
OVER THE GREAT LAKES/MIDWEST MONDAY. THE RIDGE AMPLIFIES OVER THE
CONTINENTAL DIVIDE AND SHIFTS EAST TOWARD THE FRONT RANGE TUESDAY
AS THE UPPER LOW DRIFTS INLAND AND OPENS OVER NORTHERN CA.
ISOLATED MOUNTAIN CONVECTION WILL DISSIPATE EARLY THIS EVENING WITH
THE LOSS OF ISOLATION. SKIES WILL BECOME MOSTLY CLEAR LATER THIS
EVENING. MONDAY WILL BE CARBON COPY OF TODAY WITH ISOLATED AFTERNOON
CONVECTION CONFINED TO THE HIGHER TERRAIN. A FEW OF THE SHOWERS OR
TSTORMS COULD DRIFT EAST TO THE I-25 CORRIDOR LATE IN THE AFTERNOON
BEFORE ENDING EARLY EVENING. WITH THE RIDGE AXIS NEAR THE FRONT RANGE
TUESDAY... SOME MONSOONAL MOISTURE WILL BEGIN TO WORK ITS WAY
NORTHWARD FROM WESTERN CO INTO SOUTH CENTRAL WY. THIS WILL RESULT
IN SLIGHTLY BETTER COVERAGE OF AFTERNOON AND EVENING CONVECTION ALONG
AND WEST OF THE LARAMIE RANGE. WITH A RELATIVELY WEAK SURFACE
PRESSURE GRADIENT...WIND SPEEDS WILL AVERAGE LESS THAN 15 MPH.
700MB TEMPERATURES MONDAY AFTERNOON WILL RANGE FROM 10 TO 13C YIELDING
HIGHS IN THE 80S TO NEAR 90 LOWER ELEVATIONS WITH 60S AND 70S MOUNTAINS.
TUESDAY/S HIGHS WILL BE ABOUT 5 DEGREES WARMER THAN MONDAY AS 700MB
TEMPERATURES CLIMB TO 12 TO 15C. LOWS IN THE 40S AND 50S TONIGHT AND
MONDAY NIGHT WILL WARM TO THE 50S TO LOWER 60S TUESDAY NIGHT.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 206 PM MDT SUN AUG 10 2014
MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT WITH THE OVERALL PATTERN
THROUGH THE PERIOD. BOTH THE ECMWF AND GFS SHOW STRONG UPPER-LEVEL
RIDGING OVER THE CENTRAL ROCKIES AND HIGH PLAINS ON WED IN ADVANCE
OF A VIGOROUS SHORTWAVE OVER THE PACIFIC NW. WHILE THIS WAVE SHOULD
PASS TO OUR NORTH LATER IN THE WEEK...SEVERAL ASSOCIATED PIECES OF
ENERGY WILL LIFT NORTHEAST ACROSS CO/WY ON WED AND THU. THIS OCCURS
IN LINE WITH ANOTHER SHOT OF MONSOON MOISTURE ON THE BACK SIDE OF
THE SUBTROPICAL RIDGE OVER THE SOUTHERN PLAINS...SO CONFIDENCE WAS
HIGH ENOUGH TO RAISE POPS INTO THE CHANCE CATEGORY FOR A FEW AREAS
DURING THAT TIME FRAME. THE GFS SUGGESTS PERSISTENT LEE TROUGHING
OVER THE PLAINS WILL KEEP LLVL MOISTURE INTACT OVER THE PANHANDLE
WITH DEW POINTS IN THE MID 50S. CAPES AROUND 500 TO 1000 J/KG EACH
AFTERNOON COULD AID IN STRONG STORMS...BUT SHEAR WILL GENERALLY BE
TOO WEAK BENEATH LARGER SCALE RIDGING TO SUPPORT ANYTHING MORE THAN
THE PULSE VARIETY. AFOREMENTIONED SHORTWAVE MOVES ACROSS THE NORTHERN
PLAINS OVER THE WEEKEND...PUSHING THE SFC TROUGH EAST OF THE CWA AND
USHERING IN SUFFICIENTLY DRY AIR TO REDUCE PCPN CHANCES. TEMPS THRU
THE PERIOD WILL BE SEASONAL BENEATH QUASI-ZONAL FLOW ALOFT OR MODEST
RIDGING. EXPECT LITTLE CHANGE IN HIGHS FROM DAY TO DAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY MORNING)
ISSUED AT 1138 AM MDT SUN AUG 10 2014
LOOK FOR SCT-TO-BKN COVERAGE OF CUMULUS ACROSS THE AREA AFTER 18Z
WITH ISOLATED SHOWERS AND THUNDERSTORMS OVER THE HIGHER TERRAIN.
THE HRRR MODEL SHOWS ISOLATED AFTERNOON CONVECTION ALONG AND WEST
OF THE LARAMIE RANGE...SO INTRODUCED VCTS INTO THE RWL AND LAR TAFS.
LINGERING MOISTURE COULD ALSO GIVE WAY TO A SHOWER OR STORM IN THE
NORTHERN PANHANDLE AFTER 20Z. BRIEF MVFR CONDITIONS OR ERRATIC WINDS
COULD OCCUR IF STORMS AFFECT ANY OF THE TERMINALS.
&&
.FIRE WEATHER...
ISSUED AT 241 PM MDT SUN AUG 10 2014
GENERALLY DRY CONDITIONS WILL PREVAIL THROUGH TUESDAY...EXCEPT FOR
ISOLATED AFTERNOON SHOWERS AND THUNDERSTORMS OVER AND NEAR THE
MOUNTAINS. MINIMUM RELATIVE HUMIDITIES WILL DROP TO NEAR CRITICAL
VALUES OVER NORTH AND WEST CARBON COUNTY MONDAY AND TUESDAY
AFTERNOONS. WINDS FOR THE MOST PART WILL AVERAGE 10 MPH OR LESS...
EXCEPT VARIABLE AND GUSTY IN THE VICINITY OF SHOWERS AND THUNDERSTORMS.
INCREASING MONSOONAL MOISTURE AND A FEW UPPER LEVEL DISTURBANCES
WILL RESULT IN SCATTERED SHOWERS AND THUNDERSTORMS WEDNESDAY AND
THURSDAY. SHOWER COVERAGE DECREASES LATE IN THE WEEK AS THE UPPER
RIDGE BUILDS OVER THE DISTRICTS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...JAMSKI
LONG TERM...HAMMER
AVIATION...HAMMER
FIRE WEATHER...JAMSKI
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1138 AM MDT SUN AUG 10 2014
.UPDATE...
ISSUED AT 1122 AM MDT SUN AUG 10 2014
MID LEVEL SUBSIDENCE IN WAKE OF EXITING SHORTWAVE OVER EAST CENTRAL
NE RESULTED IN MOSTLY CLEAR SKIES ACROSS MUCH OF SOUTHEAST WY THIS
MORNING. A WEAK SURFACE FRONT WAS MOVING ACROSS NORTHERN NE MARKED
BY EXTENSIVE LOW AND MID CLOUDS. 14Z HRRR COMPOSITE REFLECTIVITY
DEPICTS WIDELY SCT SHOWER/TSTORM COVERAGE INVOF SOUTHEAST WY MTNS
AND ISOLATED COVERAGE MAINLY ALONG AND EAST OF A CHADRON TO SIDNEY
NE LINE THIS AFTERNOON. ADJUSTED POPS AND CLOUD COVERAGE BASED ON
THESE TRENDS. GOING MAX TEMP FCST IS IN GOOD SHAPE.
&&
.SHORT TERM...(TODAY THROUGH MONDAY AFTERNOON)
ISSUED AT 258 AM MDT SUN AUG 10 2014
SHOWERS AND THUNDERSTORMS HAVE PUSHED OUT OF THE NEBRASKA
PANHANDLE THIS MORNING AS SUBSIDENCE SETS IN BEHIND THE SHORTWAVE
NOW OVER CENTRAL NEBRASKA. A FEW SHOWERS AND THUNDERSTORMS WILL
REDEVELOP THIS AFTERNOON...BUT MOST SHOULD BE CONFINED TO THE
MOUNTAINS AND NEARBY LOCATIONS. MODELS DO SHOW A CAP IN PLACE OVER
THE NEBRASKA PANHANDLE...AND OVER MUCH OF SOUTHEAST WYOMING EAST
OF THE LARAMIE RANGE. THE CAP IS NOT ALL THAT STRONG SO NOT 100
PERCENT RULING OUT A STORM IN THE EAST BUT THE POTENTIAL IS LOW
ENOUGH TO KEEP MUCH OF THE FORECAST AREA DRY. NOT EVEN SURE THERE
IS ENOUGH INSTABILITY FOR MUCH THUNDERSTORM ACTIVITY. CONSIDERED
ONLY MENTIONING SHOWERS GIVEN MINIMAL INSTABILITY AND RISING
HEIGHTS THIS AFTERNOON...BUT THINKING THERE WILL AT LEAST BE A FEW
LIGHTING STRIKES SO WENT WITH THUNDERSTORMS.
MONDAY WILL BE VERY SIMILAR TO TODAY BUT A BIT WARMER WITH THE
UPPER LEVEL RIDGE SHIFTING INTO THE ROCKIES. MONSOON MOISTURE WILL
BE SOUTH OF THE AREA SO THAT THE CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL BE MINIMAL AT MOST. AGAIN MAINLY LOOKING FOR
ISOLATED THUNDERSTORMS IN THE MOUNTAINS. SOME STORMS MAY SPREAD
INTO LOWER ELEVATIONS BUT UPPER LEVEL SUBSIDENCE AND LACK OF
DEEPER MOISTURE THE ODDS ARE LOW. DO NOT EXPECTED SEVERE
THUNDERSTORMS EITHER TODAY OR MONDAY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 258 AM MDT SUN AUG 10 2014
MONDAY NIGHT...HIGH AMPLITUDE RIDGING ALOFT PREVAILS...LIMITING
CONVECTIVE POTENTIAL...THOUGH WITH WEAK LOW LEVEL EASTERLY UPSLOPE
AND ADEQUATE LOW AND MID LEVEL MOISTURE...WILL SEE ISOLATED EARLY
EVENING THUNDERSTORMS NEAR THE SOUTHERN LARAMIE RANGE.
TUESDAY...DESPITE PRONOUNCED RIDGING ALOFT...WE WILL SEE AN INFLUX
OF MONSOONAL MOISTURE TO OUR WESTERN COUNTIES AND WITH WEAK LOW
LEVEL SOUTH AND SOUTHEAST UPSLOPE...AND DIFFERENTIAL HEATING OVER
THE HIGHER TERRAIN...WE EXPECT ISOLATED TO SCATTERED LATE DAY
THUNDERSTORMS ALONG AND WEST OF INTERSTATE 25.
WEDNESDAY...MONSOONAL MOISTURE FEED CONTINUES WITH AN INCREASE IN
MID LEVEL MOISTURE ALONG WITH WEAK SHORTWAVE TROUGHS ALOFT
TRAVERSING OUR COUNTIES...SPARKING SCATTERED LATE DAY THUNDERSTORMS
ALONG AND WEST OF INTERSTATE 25 WITH ISOLATED THUNDERSTORMS FURTHER
EAST.
THURSDAY...ISOLATED TO SCATTERED LATE DAY THUNDERSTORMS ON TAP
BENEATH THE LARGE SCALE RIDGE ALOFT WITH ADEQUATE LOW AND MID LEVEL
MOISTURE AND WEAK LOW LEVEL EAST UPSLOPE WINDS.
FRIDAY...NEXT MORE ENERGETIC SHORTWAVE TROUGH ALOFT MOVES OVER
WESTERN MONTANA WITH ASSOCIATED SURFACE LOW PRESSURE DEVELOPING OVER
EASTERN MONTANA...AND ITS SURFACE TROUGH EXTENDING SOUTHWARD OVER
OUR COUNTIES...SPARKING ISOLATED LATE DAY THUNDERSTORMS OVER MOST OF
OUR COUNTIES.
SATURDAY...DRIER DAY ON TAP WITH SHORTWAVE TROUGH MOVING INTO THE
WESTERN DAKOTAS...AND DRIER LOW LEVEL NORTHWEST WINDS AT THE SURFACE
OVER OUR COUNTIES...PRODUCING A DRY DAY FOR MOST LOCALES WITH
PERHAPS AN ISOLATED THUNDERSTORM IN THE AFTERNOON EAST OF A DOUGLAS
TO KIMBALL LINE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY MORNING)
ISSUED AT 1138 AM MDT SUN AUG 10 2014
VFR CONDITIONS EXPECTED TODAY AS CIGS CONTINUE TO IMPROVE AT CDR
AND AIA LATE THIS MORNING. LOOK FOR SCT-TO-BKN COVERAGE OF CUMULUS
ACROSS THE AREA AFTER 18Z WITH ISOLATED SHOWERS AND THUNDERSTORMS
OVER THE HIGHER TERRAIN. THE HRRR MODEL SHOWS CONVECTION ALONG AND
WEST OF THE LARAMIE RANGE IN A FEW HOURS...SO INTRODUCED VCTS INTO
THE RWL AND LAR TAFS. LINGERING MOISTURE COULD ALSO GIVE WAY TO A
SHOWER OR STORM IN THE NORTHERN PANHANDLE AFTER 20Z. BRIEF MVFR
CONDITIONS OR ERRATIC WINDS COULD OCCUR IF STORMS AFFECT ANY OF
THE TERMINALS.
&&
.FIRE WEATHER...
ISSUED AT 258 AM MDT SUN AUG 10 2014
LIGHT WINDS AND MILD TEMPERATURES THE NEXT SEVERAL DAYS. HUMIDITY
VALUES MAY DROP INTO THE TEENS IN THE AFTERNOON WEST OF THE
LARAMIE RANGE TODAY AND INTO EARLY THIS WEEK BUT WITH THE LIGHT
WINDS DO NOT SEE A CRITICAL FIRE WEATHER THREAT. INCREASED CHANCES
FOR SHOWERS AND THUNDERSTORMS THURSDAY AND FRIDAY AS MONSOON
MOISTURE RETURNS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...JAMSKI
SHORT TERM...LIEBL
LONG TERM...RUBIN
AVIATION...HAMMER
FIRE WEATHER...LIEBL
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1132 AM MDT SUN AUG 10 2014
.UPDATE...
ISSUED AT 1122 AM MDT SUN AUG 10 2014
MID LEVEL SUBSIDENCE IN WAKE OF EXITING SHORTWAVE OVER EAST CENTRAL
NE RESULTED IN MOSTLY CLEAR SKIES ACROSS MUCH OF SOUTHEAST WY THIS
MORNING. A WEAK SURFACE FRONT WAS MOVING ACROSS NORTHERN NE MARKED
BY EXTENSIVE LOW AND MID CLOUDS. 14Z HRRR COMPOSITE REFLECTIVITY
DEPICTS WIDELY SCT SHOWER/TSTORM COVERAGE INVOF SOUTHEAST WY MTNS
AND ISOLATED COVERAGE MAINLY ALONG AND EAST OF A CHADRON TO SIDNEY
NE LINE THIS AFTERNOON. ADJUSTED POPS AND CLOUD COVERAGE BASED ON
THESE TRENDS. GOING MAX TEMP FCST IS IN GOOD SHAPE.
&&
.SHORT TERM...(TODAY THROUGH MONDAY AFTERNOON)
ISSUED AT 258 AM MDT SUN AUG 10 2014
SHOWERS AND THUNDERSTORMS HAVE PUSHED OUT OF THE NEBRASKA
PANHANDLE THIS MORNING AS SUBSIDENCE SETS IN BEHIND THE SHORTWAVE
NOW OVER CENTRAL NEBRASKA. A FEW SHOWERS AND THUNDERSTORMS WILL
REDEVELOP THIS AFTERNOON...BUT MOST SHOULD BE CONFINED TO THE
MOUNTAINS AND NEARBY LOCATIONS. MODELS DO SHOW A CAP IN PLACE OVER
THE NEBRASKA PANHANDLE...AND OVER MUCH OF SOUTHEAST WYOMING EAST
OF THE LARAMIE RANGE. THE CAP IS NOT ALL THAT STRONG SO NOT 100
PERCENT RULING OUT A STORM IN THE EAST BUT THE POTENTIAL IS LOW
ENOUGH TO KEEP MUCH OF THE FORECAST AREA DRY. NOT EVEN SURE THERE
IS ENOUGH INSTABILITY FOR MUCH THUNDERSTORM ACTIVITY. CONSIDERED
ONLY MENTIONING SHOWERS GIVEN MINIMAL INSTABILITY AND RISING
HEIGHTS THIS AFTERNOON...BUT THINKING THERE WILL AT LEAST BE A FEW
LIGHTING STRIKES SO WENT WITH THUNDERSTORMS.
MONDAY WILL BE VERY SIMILAR TO TODAY BUT A BIT WARMER WITH THE
UPPER LEVEL RIDGE SHIFTING INTO THE ROCKIES. MONSOON MOISTURE WILL
BE SOUTH OF THE AREA SO THAT THE CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL BE MINIMAL AT MOST. AGAIN MAINLY LOOKING FOR
ISOLATED THUNDERSTORMS IN THE MOUNTAINS. SOME STORMS MAY SPREAD
INTO LOWER ELEVATIONS BUT UPPER LEVEL SUBSIDENCE AND LACK OF
DEEPER MOISTURE THE ODDS ARE LOW. DO NOT EXPECTED SEVERE
THUNDERSTORMS EITHER TODAY OR MONDAY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 258 AM MDT SUN AUG 10 2014
MONDAY NIGHT...HIGH AMPLITUDE RIDGING ALOFT PREVAILS...LIMITING
CONVECTIVE POTENTIAL...THOUGH WITH WEAK LOW LEVEL EASTERLY UPSLOPE
AND ADEQUATE LOW AND MID LEVEL MOISTURE...WILL SEE ISOLATED EARLY
EVENING THUNDERSTORMS NEAR THE SOUTHERN LARAMIE RANGE.
TUESDAY...DESPITE PRONOUNCED RIDGING ALOFT...WE WILL SEE AN INFLUX
OF MONSOONAL MOISTURE TO OUR WESTERN COUNTIES AND WITH WEAK LOW
LEVEL SOUTH AND SOUTHEAST UPSLOPE...AND DIFFERENTIAL HEATING OVER
THE HIGHER TERRAIN...WE EXPECT ISOLATED TO SCATTERED LATE DAY
THUNDERSTORMS ALONG AND WEST OF INTERSTATE 25.
WEDNESDAY...MONSOONAL MOISTURE FEED CONTINUES WITH AN INCREASE IN
MID LEVEL MOISTURE ALONG WITH WEAK SHORTWAVE TROUGHS ALOFT
TRAVERSING OUR COUNTIES...SPARKING SCATTERED LATE DAY THUNDERSTORMS
ALONG AND WEST OF INTERSTATE 25 WITH ISOLATED THUNDERSTORMS FURTHER
EAST.
THURSDAY...ISOLATED TO SCATTERED LATE DAY THUNDERSTORMS ON TAP
BENEATH THE LARGE SCALE RIDGE ALOFT WITH ADEQUATE LOW AND MID LEVEL
MOISTURE AND WEAK LOW LEVEL EAST UPSLOPE WINDS.
FRIDAY...NEXT MORE ENERGETIC SHORTWAVE TROUGH ALOFT MOVES OVER
WESTERN MONTANA WITH ASSOCIATED SURFACE LOW PRESSURE DEVELOPING OVER
EASTERN MONTANA...AND ITS SURFACE TROUGH EXTENDING SOUTHWARD OVER
OUR COUNTIES...SPARKING ISOLATED LATE DAY THUNDERSTORMS OVER MOST OF
OUR COUNTIES.
SATURDAY...DRIER DAY ON TAP WITH SHORTWAVE TROUGH MOVING INTO THE
WESTERN DAKOTAS...AND DRIER LOW LEVEL NORTHWEST WINDS AT THE SURFACE
OVER OUR COUNTIES...PRODUCING A DRY DAY FOR MOST LOCALES WITH
PERHAPS AN ISOLATED THUNDERSTORM IN THE AFTERNOON EAST OF A DOUGLAS
TO KIMBALL LINE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 258 AM MDT SUN AUG 10 2014
MAINLY VFR ACROSS THE FORECAST AREA TODAY AND TONIGHT. COULD BE
SOME PATCHY FOG EARLY THIS MORNING IN THE PLAINS WITH LIGHT WINDS
IN PLACE. THE SAME GOES FOR EARLY MONDAY MORNING AND NOT EXPECTING
WIDESPREAD FOG AT THIS TIME. A FEW THUNDERSTORMS POSSIBLE IN AND
AROUND THE MOUNTAINS OF SOUTHEAST WYOMING THIS AFTERNOON. GUSTY
WINDS POSSIBLE NEAR THUNDERSTORMS BUT GIVEN THE ISOLATED NATURE OF
STORMS TODAY AVIATION CONCERNS ARE MINIMAL.
&&
.FIRE WEATHER...
ISSUED AT 258 AM MDT SUN AUG 10 2014
LIGHT WINDS AND MILD TEMPERATURES THE NEXT SEVERAL DAYS. HUMIDITY
VALUES MAY DROP INTO THE TEENS IN THE AFTERNOON WEST OF THE
LARAMIE RANGE TODAY AND INTO EARLY THIS WEEK BUT WITH THE LIGHT
WINDS DO NOT SEE A CRITICAL FIRE WEATHER THREAT. INCREASED CHANCES
FOR SHOWERS AND THUNDERSTORMS THURSDAY AND FRIDAY AS MONSOON
MOISTURE RETURNS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...JAMSKI
SHORT TERM...LIEBL
LONG TERM...RUBIN
AVIATION...LIEBL
FIRE WEATHER...LIEBL
AREA FORECAST DISCUSSION
NWS TUCSON AZ
250 AM MST TUE AUG 12 2014
.SYNOPSIS...A STRONG INCREASE IN SHOWERS AND THUNDERSTORMS IS
EXPECTED TODAY AND TONIGHT AS MOISTURE DEEPENS AND A PASSING
DISTURBANCE HELPS TO ORGANIZE STORMS. SOME STORMS ARE EXPECTED TO
GENERATE HEAVY RAIN AND STRONG WINDS. THERE WILL BE ENOUGH MOISTURE
TO KEEP A CHANCE OF THUNDERSTORMS IN THE FORECAST THROUGH THURSDAY
BEFORE A DOWNTURN IN ACTIVITY IS EXPECTED FRIDAY AND SATURDAY.
&&
.DISCUSSION...COMPLEX FROM NORTHWEST SONORA NOW PUSHING THROUGH FAR
WESTERN PIMA AND INTO EASTERN YUMA COUNTY. ANOTHER COMPLEX SOUTH OF
NOGALES STILL HAS AN ACTIVE SOUTHERN FLANK WITH DEBRIS AND WEAK
OUTFLOW PUSHING NORTH ON THE NORTHERN FLANK.
CONSIDERABLE MOISTURE WITH PRECIPITABLE WATER VALUES FROM 1.6 INCHES
NEAR THE NEW MEXICO BORDER TO 1.8 INCHES NEAR WESTERN PIMA
COUNTY...PROBABLY EVEN A LITTLE HIGHER BY THIS AFTERNOON. A DECENT
IMPULSE EMBEDDED IN SOUTHEASTERLY FLOW WILL ENHANCE THUNDERSTORM
COVERAGE AND ORGANIZATION AS WELL AS POTENTIAL RAINFALL EFFICIENCY
THIS AFTERNOON AND TONIGHT. ELEVATED HEAVY RAIN THREAT COMBINED WITH
RECENT LOCALLY HEAVY RAINFALL IN SEVERAL AREAS FOR A FLASH FLOOD
WATCH FROM NOON TODAY THROUGH 1AM TONIGHT. GENERAL SHORT AND MEDIUM
RANGE MODEL AGREEMENT WITH LATEST HRRR DEVELOPING TRENDS THAT
DEVELOP MORE WIDESPREAD SHOWER AND THUNDERSTORM COVERAGE ALONG WITH
WELL ABOVE AVERAGE QPF VALUES. HOPEFULLY NOT A CASE WHERE WE HAVE
MORE MOISTURE THAN WE CAN USE...BUT THE AFOREMENTIONED IMPULSE
SHOULD HELP WITH THAT.
MAIN IMPULSE SHIFTS INTO NORTHERN ARIZONA LATE TONIGHT INTO
WEDNESDAY ALONG WITH STRONGEST THUNDERSTORM THREAT. WE WILL PROBABLY
BE A LITTLE WORKED OVER WEDNESDAY FOR LESS COVERAGE...BUT ANY STORMS
WE GET WILL BE PRETTY WET.
STILL LOOKS MORE AND MORE LIKE INCREASING POTENTIAL FOR A SECONDARY
HIGH CENTER RECONSOLIDATION REORIENTING THE RIDGE INTO A PARTIAL
BLOCKING POSITION FRIDAY AND SATURDAY. A COUPLE OF DOWN DAYS TO END
THE WEEK. WE SHOULD BOUNCE BACK TOWARD AN AVERAGE DAY BY SUNDAY OR
MONDAY AS THE RIDGE AMPLIFIES NORTH OF US.
&&
.AVIATION...VALID THRU 13/09Z.
ISOLD -SHRA/TS THIS MORNING. INCREASING SHOWERS AND THUNDERSTORMS
THIS AFTERNOON...BECOMING WIDESPREAD AND LIKELY AT ALL TAF LOCATIONS
BY 12/21Z. LCL MVFR VSBY CONDS AND STRONG GUSTY WINDS TO 45 KTS NEAR
TSTMS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...DAILY SCATTERED AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS ARE EXPECTED THIS WEEK...WITH A PEAK IN ACTIVITY TODAY
AND TONIGHT. STRONG...GUSTY AND ERRATIC WINDS BETWEEN 35 AND 45 MPH
ARE POSSIBLE WITH STRONGER THUNDERSTORMS. OTHERWISE...WINDS WILL
SHOW NORMAL DIURNAL TRENDS AND LESS THAN 15 MPH.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...FLASH FLOOD WATCH FOR ALL OF
SOUTHEAST ARIZONA INCLUDING AZZ501>515 FROM NOON TODAY
UNTIL 1 AM MST WEDNESDAY.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
MEYER/RASMUSSEN
AREA FORECAST DISCUSSION
NWS MIAMI FL
148 AM EDT TUE AUG 12 2014
.AVIATION...
VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE BULK OF THE TAF
PERIOD AS HIGH PRESSURE REMAINS IN CONTROL. WINDS WILL REMAIN CALM
THROUGH MID-MORNING HOURS BEFORE TURNING ONSHORE AND INCREASING
INTO THE 5-10 KT RANGE ALONG BOTH COASTS AS THE SEA BREEZES
DEVELOP AND PUSH INLAND THROUGH THE AFTERNOON HOURS. THE BEST
CHANCE FOR AFTERNOON SHOWERS WILL REMAIN INLAND AND POSSIBLY
AROUND PBI LATE IN THE DAY (WILL INCLUDE VCTS AT PBI AFTER 21Z).
/AG
&&
.PREV DISCUSSION... /ISSUED 843 PM EDT MON AUG 11 2014/
UPDATE...
CONVECTION HAS HELD ON A LITTLE LONGER THAN PREVIOUS THINKING.
HOWEVER, IT IS BEGINNING TO DIMINISH IN MANY ARES. BUT, DEVELOP IN
PORTIONS OF PALM BEACH COUNTY. THE HRRR IS NOT DOING TO WELL ON PICKING
UP ON THE CONTINUING CONVECTION. SO HAVE ANTICIPATED, BASED ON THE
CURRENT TRENDS, THAT IT WILL CONTINUE TO MOVE SLOWLY EAST AND
CONTINUE TO SHRINK IN COVERAGE OVER THE NEXT COUPLE OF HOURS,
ESPECIALLY IN PALM BEACH AS OBS DO NOT SHOW ANY SIGNIFICANT
EASTERLY FLOW TO KEEP THEM TO THE WEST OF THE COAST FROM WEST PALM
BEACH NORTH, WHERE PRECIPITATION IS ALREADY ENCROACHING ON THE
AREA. SOUTH OF THERE, CONVECTION IS FURTHER WEST, AND SHOWING
SIGNS OF WEAKENING.
PREV DISCUSSION... /ISSUED 719 PM EDT MON AUG 11 2014/
AVIATION...
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST WITH LIGHT
SURFACE WINDS. EXPECT L/V WIND THROUGH EARLY TUESDAY WITH SEA
BREEZES DEVELOPING ALONG BOTH COASTS AFT 14-16Z. THESE BOUNDARIES
WILL GENERATE SCATTERED SHRA/TSRA WITH VERY LITTLE STORM MOTION.
DUE TO THE SLOW MOVEMENT, THE PROBABILITY OF A CELL MOVING ACROSS
A TERMINAL IS VERY SMALL AND WILL NOT MENTION IN THE TAFS AT THIS
TIME.
KOB
PREV DISCUSSION... /ISSUED 258 PM EDT MON AUG 11 2014/
SHORT TERM...(TODAY-WEDNESDAY)...
BASED ON THIS MORNING`S SOUNDING AND OTHER DATA...A SAHARAN AIR
LAYER IS PRESENT TODAY ESPECIALLY WHEN LOOKING AT THE H85-H7
PORTION OF THE SOUNDING...AND SHOULD HELP LIMIT COVERAGE TODAY.
HOWEVER A FEW SLOW MOVING CELLS WERE PERSISTING ALONG THE SEA
BREEZE THROUGH CENTRAL DADE AND SOUTHEAST BROWARD. WITH WEAK FLOW
THESE STORMS WILL BE SLOW MOVING AND COULD PRODUCE VERY HEAVY
RAINFALL LEADING TO WATER PROBLEMS ALONG TYPICAL FLOOD PRONE
STREETS. MORE DEVELOPMENT IS STILL EXPECTED THROUGH THE INTERIOR
AND CAN`T RULE OUT ADDITIONAL DEVELOPMENT NEAR THE CITIES OR THE
COASTS LATE THIS AFTERNOON OR THIS EVENING. THE DEEP LAYER RIDGE
WILL REMAIN IN PLACE TOMORROW...BUT WILL WEAKEN EVENTUALLY INTO
WEDNESDAY AS ANOTHER UPPER TROUGH DIVES ACROSS THE GREAT LAKES AND
INTO THE MIDDLE ATLANTIC. IN ADDITION...A FEW WEAK DISTURBANCES
NOW MOVING ACROSS CUBA WILL BE PULLED BACK NORTH IN RESPONSE TO A
TROUGH ENTERING THE SOUTHEAST COAST. THIS COULD LEAD TO MORE
DEVELOPMENT IN COMPARISON TO WHAT IS EXPERIENCED FOR THE REST OF
TODAY AND TUESDAY. PWATS ARE ALSO FORECAST TO RISE CLOSER TO 2"
AGAIN ON WEDNESDAY PER MODEL SOUNDINGS. A GENERALLY SOUTHERN WIND
DIRECTION WILL CONTINUE THROUGH THE SHORT TERM...AND THE BEST
CHANCE FOR SHOWERS AND THUNDERSTORMS WILL REMAIN THROUGH THE
INTERIOR SECTIONS INTO WEDNESDAY.
LONG TERM...(THURSDAY-SUNDAY)...
THE LATEST EXTENDED GUIDANCE REMAINS IN DECENT AGREEMENT AND
GENERALLY INDICATES THE DEEP LAYER RIDGE REMAINING IN CONTROL ACROSS
THE REGION THROUGH THURSDAY. THIS COMBINED WITH PLENTY OF MID/UPPER
DRY AIR SHOULD KEEP THE RAIN CHANCES BELOW NORMAL WITH MAINLY
SCATTERED AFTERNOON SHOWERS ACROSS THE INTERIOR/LAKE REGION EACH
AFTERNOON. THE DEEP LAYER RIDGE IS PROGGED TO SLIGHTLY WEAKEN FRIDAY
INTO THE UPCOMING WEEKEND AS AN UPPER TROUGH DEEPENS ONCE AGAIN
ACROSS THE EASTERN STATES AND A WEAKENING FRONTAL BOUNDARY
ASSOCIATED WITH A SHORTWAVE TROUGH PUSHES SOUTH ACROSS THE REGION.
THIS COULD TRANSLATE TO SW LOW LEVEL FLOW AND INCREASING MOISTURE
AND RAIN CHANCES EACH DAY THROUGH THE WEEKEND ACROSS THE LOCAL AREA.
AVIATION...
SHOWERS ARE JUST STARTING TO POP UP TO THE WEST OF TERMINALS KFLL
AND KOPF AND KMIA. THEREFORE EAST COAST TERMINALS EITHER ASSIGNED
VCTS AT 18Z OR 19Z ESPECIALLY AS THE EAST COAST SEA BREEZE
CONTINUES TO PUSH FURTHER INLAND. THE SEA BREEZE NEAR KPBI HAS
NOT FORMED WITH A WEAK WESTERLY WIND AT TAF ISSUANCE WITH A WEAK
SEA BREEZE ASSIGNED AT 19Z. WITH ON-SET OF WEST COAST SEA BREEZE
ALREADY UNDERWAY...CONVECTION IS EXPECTED MAINLY INLAND OF
TERMINAL KAPF. WHILE CONVECTION IS EXPECTED TO BE MAINLY INLAND
AND WEST OF THE EASTERN TERMINALS...THERE COULD BE BRIEF PERIODS
OF SUB- VFR CONDITIONS WITH OCCURRENCE OF SHOWERS/THUNDERSTORMS.
MARINE...
HIGH PRESSURE WILL REMAIN IN CONTROL ACROSS THE MARINE AREAS THROUGH
MUCH OF THE WEEK WITH GENERALLY SOUTH WINDS 5-10 KTS EXPECTED.
MINOR STREET FLOODING OR STANDING WATER OVER THE TYPICAL MIAMI BEACH
AREAS ALONG THE BAY SIDE WILL REMAIN POSSIBLE THROUGH TUESDAY
MORNING`S HIGH TIDE DUE TO THE LUNAR PERIGEE. REPORTS FROM SUNDAY
EVENING`S HIGH TIDE INDICATED A SMALL AMOUNT OF WATER ON THE
STREETS...HOWEVER...NOT ENOUGH TO CLOSE ROADS OR FOR A COASTAL FLOOD
STATEMENT. THE UPCOMING HIGH TIDES WILL BE AT OR AROUND: 940 AM
TODAY AND 1009 PM THIS EVENING...WHICH ARE PREDICTED TO BE
SLIGHTLY HIGHER THAN SUNDAY`S HIGH TIDE CYCLES.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 90 79 90 79 / 20 10 30 10
FORT LAUDERDALE 92 82 91 82 / 20 10 30 10
MIAMI 92 81 91 80 / 20 10 40 10
NAPLES 94 77 92 77 / 20 10 30 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...60/BD
LONG TERM....21/KM
AVIATION...60/BD
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
229 AM CDT TUE AUG 12 2014
.DISCUSSION...
257 PM CDT
NEAR TERM FORECAST FOCUS DEALS SHOWER/THUNDERSTORM COVERAGE THROUGH
THIS EVENING...AND ADDITIONAL SHOWER CHANCES THROUGH AT LEAST
TUESDAY MORNING ESPECIALLY OVER EASTERN PARTS OF THE FORECAST AREA.
EARLY AFTERNOON SURFACE ANALYSIS DEPICTS TWO SEPARATE AREAS OF LOW
PRESSURE...ONE OVER CENTRAL WISCONSIN AND THE OTHER ACROSS WESTERN
OHIO. BOTH OF THESE SURFACE LOWS WERE ASSOCIATED WITH FAIRLY STOUT
MID-LEVEL SHORT WAVES WHICH WERE ALSO RESPONSIBLE FOR A LARGE AREA
OF SHOWERS AND THUNDERSTORMS FROM NORTHERN WI ACROSS LAKE MICHIGAN
TO THE SOUTHERN GREAT LAKES/OHIO VALLEY REGION THIS AFTERNOON. FOR
OUR LOCAL AREA...THE STRONG SHORT WAVE TROUGH SEEN IN GOES VAPOR
IMAGERY OVER MINNESOTA WILL BE THE MAIN DRIVER IN OUR WEATHER AND
PRECIP TRENDS OVER THE NEXT 18 HOURS OR SO...AS IT CONTINUES TO DIG
SOUTHEAST ACROSS NORTHERN IL THROUGH TUESDAY MORNING. ALONG WITH ITS
SURFACE REFLECTION OVER WI...A COLD FRONT EXTENDING ALONG THE
MISSISSIPPI RIVER WILL PUSH SOUTHEAST THROUGH THIS EVENING...AND
WILL BE THE FOCUS FOR SHOWERS AND A FEW THUNDERSTORMS. WHILE SURFACE
WINDS WERE ALREADY WEST-NORTHWEST AHEAD OF THE FRONT ITSELF...THUS
REDUCING CONVERGENCE ALONG THE BOUNDARY...STEEP LOW LEVEL LAPSE
RATES AND RAP MESOANALYSIS MLCAPES OF 500-1000 J/KG SHOULD BE ENOUGH
TO SUSTAIN SHOWERS/THUNDERSTORMS AHEAD OF THE FRONT THROUGH EARLY
EVENING. IN ADDITION...A FEW SHOWERS HAD DEVELOPED ALONG THE LAKE
BREEZE FROM SOUTHEAST WI INTO NORTHEAST IL...AND THESE SHOWERS AND
ISOLATED THUNDERSTORMS MAY ALSO FESTER A BIT AHEAD OF THE FRONT. ANY
OF THE STRONGER STORMS MAY PRODUCE BRIEF HEAVY DOWNPOURS...AND
PERHAPS SOME BRIEF GUSTY WINDS WITH STORMS ALONG THE FRONT DUE TO
THE STEEP LOW LEVEL LAPSE RATES.
THE STRONG MINNESOTA SHORT WAVE WILL AMPLIFY/DEEPEN AN UPPER TROUGH
OVER THE WESTERN LAKES TONIGHT...WITH THE SURFACE LOWS CONSOLIDATING
AND DEEPENING OVER LOWER MICHIGAN. A FEW SHOWERS MAY LINGER OVER
NORTHEASTERN PARTS OF THE CWA AND SOUTHERN LAKE MICHIGAN TUESDAY
MORNING AS THE MAIN VORT MOVES THROUGH...BEFORE SUBSIDENCE INDICATED
BY 40 METER H5 HEIGHT RISES SPREADS IN DURING THE AFTERNOON. NORTH
WINDS STRENGTHENING BEHIND THE DEEPENING LOW WILL EVENTUALLY PULL
COOLER AND DRIER AIR INTO THE REGION TUESDAY AFTERNOON/NIGHT. AFTER
TEMPS REACHING THE LOW 80S TODAY (WHERE CLOUDS DID NOT PREVENT
IT)... COOLER 70S EXPECTED FOR HIGHS TUESDAY...AND SOME LOW 50S FOR
LOWS TUESDAY NIGHT!
GUIDANCE INDICATES ANOTHER WEAKER SHORT-WAVE DROPPING SOUTHEAST
ACROSS THE WESTERN LAKES WEDNESDAY...WITH A WEAK SURFACE WAVE AND
TROUGH PUSHING SOUTH ACROSS THE REGION DURING THE AFTERNOON. SOME
MODELS ARE TRYING TO SQUEEZE OUT A LITTLE PATCHY LIGHT QPF HINTING
AT SOME SHOWERS ALONG/AHEAD OF THE TROUGH DURING THE AFTERNOON...
THOUGH MOST OF THIS IS ACROSS WI/NORTHEAST IA AND HAVE LOW ENOUGH
CONFIDENCE IN IT IMPACTING THE FORECAST AREA TO LEAVE IT OUT OF THE
FORECAST AT THIS TIME. SIMILAR POTENTIAL FOR THURSDAY AFTERNOON
FARTHER SOUTH DEPENDING UPON WHERE THE TROUGH IS BY THEN. OTHERWISE
HIGH PRESSURE BUILDS INTO THE REGION WEDNESDAY NIGHT AND THURSDAY
WITH LIGHTER WINDS AND A MODERATION IN TEMPS BACK TO THE 75-80
DEGREE RANGE THURSDAY AND AROUND 80 FRIDAY WITH ATTENDANT LAKE
BREEZES. THE HIGH THEN DRIFTS OFF TO THE EAST FRIDAY NIGHT AND
SATURDAY...WITH AN EVENTUAL RETURN OF WARM/MOIST ADVECTION FLOW INTO
THE WEEKEND AND EARLY NEXT WEEK. IN THE EXTENDED RANGE...GEM...GFS
AND ECMWF ALL BRING SOME PRECIP POTENTIAL BACK TO THE AREA BY FRIDAY
NIGHT...THOUGH THERE ARE SOME TIMING DIFFERENCES BETWEEN THE GLOBAL
GUIDANCE BY DAYS 6-7. THUS HAVE MAINTAINED BLENDED GUIDANCE APPROACH
WITH GENERALLY LOW-CHANCE POPS AND TEMPS WARMING BACK INTO THE
LOW-MID 80S THROUGH THE WEEKEND.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* PATCHY IFR CIGS DEVELOPING EARLY THIS MORNING...SHUD IMPROVE TO
LOW END MVFR BY 12Z.
* NW WINDS TURNING N WITH A FEW GUSTS TO 20KT BEFORE 12Z...THEN
FREQUENT GUSTS AFT 14Z UP TO 24KT.
* PATCHY LGT SHRA THRU 10Z.
BEACHLER
//DISCUSSION...UPDATED 06Z...
LOW PRESSURE HAS PUSHED EAST INTO SOUTHEAST MICHIGAN EARLY THIS
MORNING...WITH WINDS GENERALLY FROM 300-330 DEG ACROSS THE TAF
SITES AND ALL OTHER NORTHERN IL/NORTHWEST IN AIRFIELDS. CIGS HAVE
BEEN STEADILY DIMINISHING INTO LOW END MVFR CONDS...WITH PSBL CIGS
DIPPING TO ARND 1KFT AGL JUST BEFORE DAYBREAK. IR IMAGERY SHOWS
THE WRAP AROUND MOISTURE AND CLOUDS PIVOTING EAST ACROSS NORTHERN
IL INTO NORTHWEST IN THIS MORNING...WITH MUCH DRIER AIR ACROSS
NORTHWEST WISC SLOWLY SLIDING SOUTHEAST TOWARDS THE TAF SITES. IT
DOES APPEAR THAT AFT THE BRIEF PERIOD OF LGT SHRA CIGS WILL ONLY
REBOUND FOR MUCH OF THE DAY INTO LOW END MVFR CONDS...OR ARND
2100-2900FT AGL. THEN LATE THIS AFTN ENOUGH DRY AIR SHUD PUSH INTO
THE TAF SITES TO SCT CIGS AND PUSH THEM BACK TO VFR CONDS.
WINDS WILL BE TURNING NORTHERLY AND WITH BETTER MIXING EXPECT
SPEEDS TO INCREASE SHORTLY AFT DAYBREAK TO ARND 10-14KT. GUSTS
WILL ALSO DEVELOP AND GUIDANCE IS INDICATING GUSTS TO TOP OUT ARND
22-24KT BY 14Z THRU 02Z WED OR SHORTLY AFT SUNSET WINDS WILL
DIMINISH.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN LGT SHRA ONLY LASTING FOR A FEW HOURS THIS
MORNING.
* HIGH CONFIDENCE IN WIND DIR/SPEED AND GUSTS LATER TODAY.
* MEDIUM/HIGH CONFIDENCE IN CIGS HOVERING ARND LOW END MVFR
CONDS...LOW CONFIDENCE IN CIGS DIPPING TO IFR.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...VFR. WX NIL. NORTHWEST WINDS WITH POSSIBLE SHIFT TO
NORTHEAST WITH LAKE BREEZE.
THURSDAY...VFR. WX NIL. NORTHEAST WINDS UP TO 10KT.
FRIDAY...VFR. LIGHT SOUTH WINDS TURN SOUTHEAST WITH LAKE BREEZE IN
THE AFTERNOON. SLIGHT CHANCE TSRA OVERNIGHT.
SATURDAY AND SUNDAY...SOUTH WINDS TO 10 KT. SLIGHT CHANCE TSRA
OVERNIGHT.
KREIN
&&
.MARINE...
217 AM CDT
MAIN ISSUES FOR TODAY WILL BE ON POTENTIAL GALES FOR THE NORTHERN
HALF OF THE LAKE...AND DEVELOPING SMALL CRAFT CONDITIONS FOR THE
ILLINOIS AND NORTHWEST INDIANA NEARSHORE WATERS.
WINDS LATE LAST NIGHT BEGAN TO INCREASE ACROSS THE NORTHERN HALF
OF THE LAKE...WITH A COUPLE SITES TOUCHING GALE CONDITIONS. THOSE
SITES HAVE SINCE DIMINISHED TO GUSTS BETWEEN 28-30KT. THERE IS
SOME COOLER AIR FLOWING ACROSS THE LAKE AND THE GRADIENT HAS BEEN
A LITTLE TIGHTER...WHICH COULD STILL SUPPORT SOME DEGREE OF
FREQUENT GALES. THE LOW WILL CONTINUE TO LIFT NORTHEAST THROUGHOUT
THE DAY...ALLOWING BROAD SFC RIDGE TO PUSH IN FROM THE WEST. THIS
WILL ALLOW WINDS TO STEADILY DIMINISH LATER THIS
AFTN/EVE...HOWEVER WAVES WILL REMAIN HAZARDOUS TO SMALL CRAFT IN
THE SOUTHERN TIP OF THE LAKE. THIS WILL ESPECIALLY BE TRUE FOR THE
INDIANA NEARSHORE WATERS. THEN HIGH PRESSURE ARRIVES WED AND
LINGERS THRU FRI...THEN HIGH PRESSURE DRIFTS EAST WITH FLOW
TURNING SOUTHERLY TO SOUTHWESTERLY FOR THE WEEKEND.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014...9 AM TUESDAY TO 4 AM
WEDNESDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...9 AM TUESDAY TO 10 AM
WEDNESDAY.
LM...GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...7 AM
TUESDAY TO 3 PM TUESDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...9 AM TUESDAY TO 4
AM WEDNESDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...9 AM TUESDAY TO 10
AM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1252 AM CDT TUE AUG 12 2014
.DISCUSSION...
257 PM CDT
NEAR TERM FORECAST FOCUS DEALS SHOWER/THUNDERSTORM COVERAGE THROUGH
THIS EVENING...AND ADDITIONAL SHOWER CHANCES THROUGH AT LEAST
TUESDAY MORNING ESPECIALLY OVER EASTERN PARTS OF THE FORECAST AREA.
EARLY AFTERNOON SURFACE ANALYSIS DEPICTS TWO SEPARATE AREAS OF LOW
PRESSURE...ONE OVER CENTRAL WISCONSIN AND THE OTHER ACROSS WESTERN
OHIO. BOTH OF THESE SURFACE LOWS WERE ASSOCIATED WITH FAIRLY STOUT
MID-LEVEL SHORT WAVES WHICH WERE ALSO RESPONSIBLE FOR A LARGE AREA
OF SHOWERS AND THUNDERSTORMS FROM NORTHERN WI ACROSS LAKE MICHIGAN
TO THE SOUTHERN GREAT LAKES/OHIO VALLEY REGION THIS AFTERNOON. FOR
OUR LOCAL AREA...THE STRONG SHORT WAVE TROUGH SEEN IN GOES VAPOR
IMAGERY OVER MINNESOTA WILL BE THE MAIN DRIVER IN OUR WEATHER AND
PRECIP TRENDS OVER THE NEXT 18 HOURS OR SO...AS IT CONTINUES TO DIG
SOUTHEAST ACROSS NORTHERN IL THROUGH TUESDAY MORNING. ALONG WITH ITS
SURFACE REFLECTION OVER WI...A COLD FRONT EXTENDING ALONG THE
MISSISSIPPI RIVER WILL PUSH SOUTHEAST THROUGH THIS EVENING...AND
WILL BE THE FOCUS FOR SHOWERS AND A FEW THUNDERSTORMS. WHILE SURFACE
WINDS WERE ALREADY WEST-NORTHWEST AHEAD OF THE FRONT ITSELF...THUS
REDUCING CONVERGENCE ALONG THE BOUNDARY...STEEP LOW LEVEL LAPSE
RATES AND RAP MESOANALYSIS MLCAPES OF 500-1000 J/KG SHOULD BE ENOUGH
TO SUSTAIN SHOWERS/THUNDERSTORMS AHEAD OF THE FRONT THROUGH EARLY
EVENING. IN ADDITION...A FEW SHOWERS HAD DEVELOPED ALONG THE LAKE
BREEZE FROM SOUTHEAST WI INTO NORTHEAST IL...AND THESE SHOWERS AND
ISOLATED THUNDERSTORMS MAY ALSO FESTER A BIT AHEAD OF THE FRONT. ANY
OF THE STRONGER STORMS MAY PRODUCE BRIEF HEAVY DOWNPOURS...AND
PERHAPS SOME BRIEF GUSTY WINDS WITH STORMS ALONG THE FRONT DUE TO
THE STEEP LOW LEVEL LAPSE RATES.
THE STRONG MINNESOTA SHORT WAVE WILL AMPLIFY/DEEPEN AN UPPER TROUGH
OVER THE WESTERN LAKES TONIGHT...WITH THE SURFACE LOWS CONSOLIDATING
AND DEEPENING OVER LOWER MICHIGAN. A FEW SHOWERS MAY LINGER OVER
NORTHEASTERN PARTS OF THE CWA AND SOUTHERN LAKE MICHIGAN TUESDAY
MORNING AS THE MAIN VORT MOVES THROUGH...BEFORE SUBSIDENCE INDICATED
BY 40 METER H5 HEIGHT RISES SPREADS IN DURING THE AFTERNOON. NORTH
WINDS STRENGTHENING BEHIND THE DEEPENING LOW WILL EVENTUALLY PULL
COOLER AND DRIER AIR INTO THE REGION TUESDAY AFTERNOON/NIGHT. AFTER
TEMPS REACHING THE LOW 80S TODAY (WHERE CLOUDS DID NOT PREVENT
IT)... COOLER 70S EXPECTED FOR HIGHS TUESDAY...AND SOME LOW 50S FOR
LOWS TUESDAY NIGHT!
GUIDANCE INDICATES ANOTHER WEAKER SHORT-WAVE DROPPING SOUTHEAST
ACROSS THE WESTERN LAKES WEDNESDAY...WITH A WEAK SURFACE WAVE AND
TROUGH PUSHING SOUTH ACROSS THE REGION DURING THE AFTERNOON. SOME
MODELS ARE TRYING TO SQUEEZE OUT A LITTLE PATCHY LIGHT QPF HINTING
AT SOME SHOWERS ALONG/AHEAD OF THE TROUGH DURING THE AFTERNOON...
THOUGH MOST OF THIS IS ACROSS WI/NORTHEAST IA AND HAVE LOW ENOUGH
CONFIDENCE IN IT IMPACTING THE FORECAST AREA TO LEAVE IT OUT OF THE
FORECAST AT THIS TIME. SIMILAR POTENTIAL FOR THURSDAY AFTERNOON
FARTHER SOUTH DEPENDING UPON WHERE THE TROUGH IS BY THEN. OTHERWISE
HIGH PRESSURE BUILDS INTO THE REGION WEDNESDAY NIGHT AND THURSDAY
WITH LIGHTER WINDS AND A MODERATION IN TEMPS BACK TO THE 75-80
DEGREE RANGE THURSDAY AND AROUND 80 FRIDAY WITH ATTENDANT LAKE
BREEZES. THE HIGH THEN DRIFTS OFF TO THE EAST FRIDAY NIGHT AND
SATURDAY...WITH AN EVENTUAL RETURN OF WARM/MOIST ADVECTION FLOW INTO
THE WEEKEND AND EARLY NEXT WEEK. IN THE EXTENDED RANGE...GEM...GFS
AND ECMWF ALL BRING SOME PRECIP POTENTIAL BACK TO THE AREA BY FRIDAY
NIGHT...THOUGH THERE ARE SOME TIMING DIFFERENCES BETWEEN THE GLOBAL
GUIDANCE BY DAYS 6-7. THUS HAVE MAINTAINED BLENDED GUIDANCE APPROACH
WITH GENERALLY LOW-CHANCE POPS AND TEMPS WARMING BACK INTO THE
LOW-MID 80S THROUGH THE WEEKEND.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* PATCHY IFR CIGS DEVELOPING EARLY THIS MORNING...SHUD IMPROVE TO
LOW END MVFR BY 12Z.
* NW WINDS TURNING N WITH A FEW GUSTS TO 20KT BEFORE 12Z...THEN
FREQUENT GUSTS AFT 14Z UP TO 24KT.
* PATCHY LGT SHRA THRU 10Z.
BEACHLER
//DISCUSSION...UPDATED 06Z...
LOW PRESSURE HAS PUSHED EAST INTO SOUTHEAST MICHIGAN EARLY THIS
MORNING...WITH WINDS GENERALLY FROM 300-330 DEG ACROSS THE TAF
SITES AND ALL OTHER NORTHERN IL/NORTHWEST IN AIRFIELDS. CIGS HAVE
BEEN STEADILY DIMINISHING INTO LOW END MVFR CONDS...WITH PSBL CIGS
DIPPING TO ARND 1KFT AGL JUST BEFORE DAYBREAK. IR IMAGERY SHOWS
THE WRAP AROUND MOISTURE AND CLOUDS PIVOTING EAST ACROSS NORTHERN
IL INTO NORTHWEST IN THIS MORNING...WITH MUCH DRIER AIR ACROSS
NORTHWEST WISC SLOWLY SLIDING SOUTHEAST TOWARDS THE TAF SITES. IT
DOES APPEAR THAT AFT THE BRIEF PERIOD OF LGT SHRA CIGS WILL ONLY
REBOUND FOR MUCH OF THE DAY INTO LOW END MVFR CONDS...OR ARND
2100-2900FT AGL. THEN LATE THIS AFTN ENOUGH DRY AIR SHUD PUSH INTO
THE TAF SITES TO SCT CIGS AND PUSH THEM BACK TO VFR CONDS.
WINDS WILL BE TURNING NORTHERLY AND WITH BETTER MIXING EXPECT
SPEEDS TO INCREASE SHORTLY AFT DAYBREAK TO ARND 10-14KT. GUSTS
WILL ALSO DEVELOP AND GUIDANCE IS INDICATING GUSTS TO TOP OUT ARND
22-24KT BY 14Z THRU 02Z WED OR SHORTLY AFT SUNSET WINDS WILL
DIMINISH.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN LGT SHRA ONLY LASTING FOR A FEW HOURS THIS
MORNING.
* HIGH CONFIDENCE IN WIND DIR/SPEED AND GUSTS LATER TODAY.
* MEDIUM/HIGH CONFIDENCE IN CIGS HOVERING ARND LOW END MVFR
CONDS...LOW CONFIDENCE IN CIGS DIPPING TO IFR.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...VFR. WX NIL. NORTHWEST WINDS WITH POSSIBLE SHIFT TO
NORTHEAST WITH LAKE BREEZE.
THURSDAY...VFR. WX NIL. NORTHEAST WINDS UP TO 10KT.
FRIDAY...VFR. LIGHT SOUTH WINDS TURN SOUTHEAST WITH LAKE BREEZE IN
THE AFTERNOON. SLIGHT CHANCE TSRA OVERNIGHT.
SATURDAY AND SUNDAY...SOUTH WINDS TO 10 KT. SLIGHT CHANCE TSRA
OVERNIGHT.
KREIN
&&
.MARINE...
403 PM CDT
THE HIGHER WINDS AND WAVES FROM EARLIER THIS MORNING HAVE SINCE
DIMINISHED/SUBSIDED TODAY AS A WEAKER SURFACE GRADIENT HAS SETTLED
IN...BETWEEN WEAKENING LOW PRESSURE WEST OF THE LAKE AND A
NORTHWARD MOVING LOW PRESSURE OVER THE OHIO VALLEY. THE GENERALLY
LIGHTER WINDS CURRENTLY OVER THE LAKE WILL OBSERVE AN INCREASING
TREND THIS EVENING INTO TONIGHT AS THE OHIO VALLEY LOW DEEPENS
WHILE LIFTING THROUGH THE EASTERN GREAT LAKES...WITH NORTHERLY TO
30 KT WINDS LIKELY BY LATE TONIGHT AND EARLY TUESDAY MORNING.
LATEST TRENDS HAVE SHOWN THAT NORTHERLY GALES WILL BE POSSIBLE
TUESDAY MORNING INTO TUESDAY AFTERNOON MAINLY FOR THE NORTHERN
HALF OF THE LAKE...INSTEAD OF THE PREVIOUSLY MENTIONED OCCASIONAL
GALE FORCE GUSTS. WITH THIS POSSIBILITY...HAVE ISSUED A GALE WATCH
FOR THE NORTH HALF THIS AFTERNOON FOR THIS PERIOD. WILL NEED TO
CONTINUE TO MONITOR LATER TRENDS FOR THIS INCREASED POSSIBILITY OF
GALES. THESE NORTHERLY WINDS WILL ALLOW WAVES TO BUILD DOWN THE
LENGTH OF THE LAKE...WITH WINDS AND WAVES HAZARDOUS FOR SMALL
CRAFT LIKELY TUESDAY INTO TUESDAY NIGHT AND WEDNESDAY MORNING.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014...9 AM TUESDAY TO 4 AM
WEDNESDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...9 AM TUESDAY TO 10 AM
WEDNESDAY.
LM...GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...7 AM
TUESDAY TO 3 PM TUESDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...9 AM TUESDAY TO 4
AM WEDNESDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...9 AM TUESDAY TO 10
AM 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
NWS GOODLAND KS
237 AM MDT TUE AUG 12 2014
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 235 AM MDT TUE AUG 12 2014
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW HIGHLY AMPLIFIED
RIDGE CENTERED OVER THE CENTRAL ROCKIES EXTENDING WELL INTO THE
CANADIAN ROCKIES. THE EASTERN EXTENT OF THIS RIDGE HAS SHIFTED OVER
OUR CWA...WITH THE MAIN STORM TRACK NOW WELL EAST. MONSOONAL PLUME
IS ALSO ORIENTATED MORE OVER THE GREAT BASIN THAT CENTRAL ROCKIES
WITH LITTLE IN THE WAY OF UPSTREAM ACTIVITY OVER THE NORTHERN PLAINS.
AT THE SURFACE HIGH PRESSURE REMAINS IN PLACE THE CENTRAL AND HIGH
PLAINS.
WITH H5 RIDGE NOW HOLDING MUCH MORE INFLUENCE ON WX OVER OUR
CWA...DRY CONDITIONS SHOULD CONTINUE THROUGH AT LEAST WEDNESDAY
AFTERNOON. GUIDANCE HAS SHIFTED TRACK OF A WEAK SHORTWAVE WEDNESDAY
NIGHT TOWARDS THE NORTHERN PLAINS...WITH EVEN THE SOUTHERNMOST
REFLECTION OF THIS BARELY INFLUENCING SW NEBRASKA. WITH THE PRECIP
SIGNAL SHIFTED NORTH AND A VERY DRY AIR MASS IN PLACE (ON ALL
AVAILABLE GUIDANCE) I REMOVED THUNDERSTORM MENTION FROM WEDNESDAY
NIGHT. BY THURSDAY A STRONGER SHORTWAVE WILL BEGIN TO BREAKDOWN THE
WESTERN PART OF THE RIDGE ALLOWING BETTER FORCING TO MOVE TOWARDS
THE PLAINS...AND WITH AT LEAST MODERATE INSTABILITY AND SHEER IN
PLACE WE COULD START TO SEE THUNDERSTORM INITIATION BY THURSDAY
AFTERNOON IN THE WEST. THE BEST CHANCES WILL HOLD OFF UNTIL THURSDAY
NIGHT WHEN BETTER FORCING WILL BE IN PLACE.
TEMPERATURES SHOULD RETURN TO SEASONAL VALUES IN THE UPPER 80S
TODAY...WITH CONTINUED WARMING THROUGH THURSDAY. THE WARMEST DAY
THIS WEEK WILL LIKELY BE ON THURSDAY WHEN GOOD SOUTHERLY FLOW WILL
SUPPORT TEMPERATURES AT LEAST IN THE MIDDLE 90S. GUIDANCE IS SHOWING
H85 TEMPS AROUND 30C WHICH WITH GOOD MIXING (LITTLE CLOUD COVER) MAY
SUPPORT TEMPS IN THE UPPER 90S/NEAR 100F.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 235 AM MDT TUE AUG 12 2014
NO SIGNIFICANT CHANGES WERE NEEDED IN THE EXTENDED. THE BIGGEST
CHALLENGE WILL CONTINUE TO BE TIMING OF BEST PRECIPITATION CHANCES.
MEDIUM RANGE GUIDANCE SHOWS A WEST/NORTHWESTERLY UPPER FLOW REGIME
WITH PERIODIC SHORTWAVE TROUGHS PASSING THROUGH. ONE WAVE WILL MOVE
EASTWARD THROUGH THE CENTRAL HIGH PLAINS ON FRIDAY BRINGING
SLIGHT/LOW CHANCE POPS TO THE ENTIRE FORECAST AREA. BEYOND
FRIDAY...GFS IS MORE PROGRESSIVE THAN ECMWF AND GFS ENSEMBLE SPREAD
GROWS. GIVEN DIFFERENCES IN THE MODELS TYPICAL OF THIS TYPE PATTERN
WITH TRANSIENT WEAK SHORTWAVES DID NOT TRY TO SEPARATE OUT BEST
CHANCES AND ACCEPTED THE MEDIUM RANGE CONSENSUS BLEND FOR POPS THIS
WEEKEND INTO EARLY NEXT WEEK. TEMPERATURES SHOULD BE SLIGHTLY ABOVE
NORMAL THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 951 PM MDT MON AUG 11 2014
VFR CONDITIONS WITH LIGHT WINDS ARE TO CONTINUE FOR THE NEXT 24
HOURS. LEE TROUGH DEVELOPMENT OVER COLORADO WILL LEAD TO A WIND
SHIFT OVERNIGHT AT KMCK. WINDS HAVE ALREADY SHIFTED AROUND AT
KGLD. A FEW DAYTIME CUMULUS ARE POSSIBLE BUT FORECAST SOUNDINGS
INDICATE A DRIER AIR MASS IN PLACE COMPARED TO RECENT DAYS SO OPTED
TO LEAVE OUT A CUMULUS MENTION. NO FOG/STRATUS IS ANTICIPATED THIS
MORNING AS THE BOUNDARY LAYER IS DRIER THAN RECENT MORNINGS AND
TEMPERATURES SHOULD NOT COOL AS MUCH WITH WINDS REMAINING AROUND
6-8 KTS OVERNIGHT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BRB
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
103 AM EDT Tue Aug 12 2014
...Updated Aviation Discussion...
...Forecast Update...
Issued at 945 PM EDT Mon Aug 11 2014
Have one more significant cell in the middle of the forecast area,
which developed along a theta-e ridge and just ahead of weak PV
anomaly. May yet see a few more spots develop east of the I-65
corridor the next couple of hours, but coverage will be limited by
loss of heating. Latest RUC bumps ahead the timing of some showers
moving in for daybreak tomorrow so have added this into the forecast
as well as put in patchy fog, given weak surface flow and the rains
that fell today.
Issued at 730 PM EDT Mon Aug 11 2014
Cold front is right along the Ohio River this hour and forecast to
continue sagging slowly south. Still expect a secondary front to
move through the region Tuesday, so cannot rule out additional
showers toward daybreak over the north. Till then, we still have
banded precipitation to deal with, torrential at times. Most cells
have been progressive today, but over the last hour some training of
storms has occurred over parts of the Bluegrass. With the loss of
heating, expect our convection to weaken significantly. Updated the
forecast to bring grids closer to current observations.
.SHORT TERM (Now through Tuesday Night)...
Issued at 257 PM EDT Mon Aug 11 2014
We will have one more day of unsettled weather before drier and
cooler conditions prevail for the second half of the week. For
tonight through tomorrow an upper level trough will continue to dig
into the Great Lakes and Ohio Valley region. This trough will then
start to shift off to the east Tuesday night. A vortmax is moving
across the region now and another will swing through tomorrow
afternoon. At the surface low pressure currently across northern
IN/OH will drag a weak cold front through tonight.
Scattered to numerous showers and thunderstorms will continue across
the forecast area this afternoon and early evening. With PWAT values
hovering near 2" these storms will be very heavy rain producers.
Training of storms will potentially cause ponding of water or
localized flooding. In addition, a few strong wind gusts could be
realized from the strongest storms.
Storms will decrease tonight near sunset and much of the area should
go dry overnight as the front moves through. A few showers could
linger in the east, however. For tomorrow, scattered showers and
storms will again develop as the reinforcing vortmax swings through.
Moisture will not be as high tomorrow, so rainfall intensity should
not be as high as today.
Highs tomorrow look to be a bit cooler than today in the upper 70s
to lower 80s. Lows tonight will be in the mid to upper 60s. As drier
air filters in tomorrow night, lows will drop much lower, bottoming
out in the upper 50s to lower 60s.
.LONG TERM (Wednesday through Monday)...
Issued at 250 PM EDT Mon Aug 11 2014
We`ll begin the long term period with a dry, relatively cool period
as an upper level trough sits over the region with high pressure at
the surface. Expect partly to mostly sunny skies Wed-Sat with high
temps in the upper 70s to mid 80s. Wed looks to be the coolest day
in the long term period with highs in the upper 70s to around 80
across the area. We will start to see some weak ridging work in
from the west by Sat allowing temps to warm into the mid 80s over
most locations. Low temps will be in the upper 50s to lower 60s.
In addition to unseasonably cool temps, humidity levels will be much
lower than the beginning of the week as dewpts drop back into the
50s.
As we head into the beginning of next week, a shortwave upper level
trough will approach the region. Ahead of the trough southerly flow
will usher in moist, unstable air and eventually rain chances.
Models have slowed down on the 12Z runs today delaying rain until at
least Sun night or Mon. Thus, will eliminate POPs for Sun and stick
to low POPs (20-30%) for Sun night-Mon. Temps will climb back into
the upper 80s and possibly approaching 90 by the beginning of next
week.
&&
.AVIATION (06Z TAF Update)...
Issued at 100 AM EDT Tue Aug 12 2014
Main challenge in this TAF set is the overnight fog potential.
Plenty of low-level moisture in place due to recent rains,
especially at BWG and LEX. Main factor weighing against fog
formation will be winds staying up out of the W-SW around 5-6 kt.
LEX has already seen a low stratus ceiling develop, and while there
may be just enough wind to keep this up as stratus, still expect IFR
for much of the night, be it ceiling or vis. Will include a TEMPO
for vis restrictions toward morning, but most likely keep the LIFR
ceilings anyway unless changes are evident by issuance time. BWG
should roll MVFR most of the night, but given its propensity for
fog, at least a TEMPO for IFR vis seems prudent. SDF should stay
above fuel-alternate thresholds.
Fog/stratus should mix out fairly well as WNW winds pick up, but it
could take most of the morning for this process to occur. Expect to
go VFR around midday, with LEX being the last to improve. Cold pool
aloft will support a decent cu field, and even a ceiling at SDF/LEX.
Can`t rule out an isolated shower or T-storm, but chances are too
low to include. Westerly wind gusts in the afternoon will push 20
kt, then winds diminish and skies clear after sunset.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........RJS
Short Term.....EER
Long Term......AMS
Aviation.......RAS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
438 AM EDT TUE AUG 12 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 410 PM EDT MON AUG 11 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE OVER
THE ROCKIES AND A TROUGH FROM HUDSON BAY INTO THE UPPER MS VALLEY.
AT THE SFC...A FRONT EXTENDED FROM SE LAKE SUPERIOR INTO NE WI. A
DEEPENING TROUGH WITH AN 85 KNOT 250 MB JET MOVING THROUGH WRN
WI...AND 800-600 MB FGEN SUPPORTED A LARGE ARA OF PCPN THROUGH WRN
UPPER MI. ANOTHER AREA OF SHOWERS INTO SE AND ERN UPPER MI WAS
ASSOCIATED WITH A WEAK SHRTWV TROUGH INTO NRN LAKE MI.
TONIGHT...EXPECT SHRA COVERAGE TO GRADUALLY INCREASE OVER CNTRL
UPPER MI AS THE WEAKENING FGEN FORCING SHIFTS TO THE EAST. WITH
MINIMAL/SKINNY MUCAPE AOB 400 J/KG AND NO TSRA OBSERVED TODAY...ONLY
SLIGHT CHANCE TSRA WAS RETAINED THROUGH THIS EVENING. AS THE TROUGH
CONTINUED TO DEEPEN AND LOW PRES OVER WRN LOWER MI LIFTS TO LAKE
HURON...NRLY FLOW WILL STRENGTHEN ACROSS UPPER MI. THE COMBINATION OF
THE MID LEVEL FORCING AND INCREASED ONSHORE/UPSLOPE FLOW WILL ALSO
BRING AN INCREASE IN LIGHT RAIN OR DRIZZLE INTO N CNTRL UPPER MI
OVERNIGHT.
TUE...AREAS OF LIGHT RAIN OR DRIZZLE MAY CONTINUE IN THE MORNING
THROUGH N CNTRL UPPER AND E UPPER MI AND GRADUALLY DIMINISH INTO THE
AFTERNOON AS THE DEEP MOISTURE FINALLY SLIDES TO THE EAST...PER NAM
850-700 MB RH FCST. OTHERWISE...COOLER CONDITIONS ARE EXPECTED WITH
BRISK NRLY WINDS KEEPING TEMPS IN THE 60S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 438 AM EDT TUE AUG 12 2014
WITH THE 500MB TROUGH /OR AT TIMES CUT OFF LOW/ SET UP OVER THE E
THIRD OF ONTARIO AND THROUGH THE LOWER GREAT LAKES...UPPER MI WILL
BE STUCK IN NW FLOW.
WHILE THE MAIN SFC LOW EXITS ALONG THE ONTARIO/QUEBEC BORDER BY 12Z
WEDNESDAY...IT WILL STILL INFLUENCE UPPER MI BY ROTATING A SECONDARY
COLD FRONT/TROUGH OVER THE CWA WEDNESDAY MORNING. WHILE THE BOUNDARY
IS EXPECTED TO BE DRY...WINDS SHOULD SHIFT BACK TO THE N AND BECOME
BREEZY AGAIN THANKS TO THE LARGE CANADIAN HIGH RAPIDLY SINKING INTO
THE AREA. EXPECT THE SFC HIGH TO PUSH ACROSS W AND CENTRAL UPPER MI
WEDNESDAY EVENING. PW VALUES WILL QUICKLY FALL TO AROUND 40 PERCENT
OF NORMAL BY THE END OF THE DAY WEDNESDAY...AND REMAIN NEAR THE SAME
VALUES THROUGH AT LEAST DAYBREAK THURSDAY. COOLED OFF WEDNESDAY
NIGHT/THURSDAY MORNING INTO THE LOW 40S OVER THE INTERIOR W HALF.
THE COOLEST GUIDANCE VALUES ARE SUGGESTION BELOW FREEZING VALUES
OVER THE TYPICAL COOL SPOTS.
LOOK FOR THE 500MB LOW TO SHIFT INTO S QUEBEC THURSDAY
MORNING...WHERE IT WILL REMAIN THROUGH FRIDAY NIGHT. NO QUICK
WARMUPS ARE IN STORE...WITH SLOWLY MODERATING HIGH TEMPERATURES
RISING TO NEAR NORMAL VALUES BY FRIDAY.
BOTH THE ECMWF AND GFS ARE INDICATING A DECENT SHORTWAVE AND SFC LOW
TO SINK IN FROM THE NW CORNER OF ONTARIO FRIDAY NIGHT INTO SATURDAY.
DID NOT MAKE TOO MANY LARGE SCALE CHANGES TO THE ONGOING POPS FOR
FRIDAY /MAINLY AFTERNOON/ THROUGH SATURDAY..ASSISTED BY A SFC LOW
DIPPING ACROSS THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY EVENING)
ISSUED AT 130 AM EDT TUE AUG 12 2014
MVFR CONDITIONS WILL CONTINUE AT IWD AND CMX OVERNIGHT BEFORE DRIER
AIR MOVES IN FOR TUE MORNING AND LEADS TO VFR CONDITIONS THROUGH THE
REST OF THE PERIOD.
RAIN ALONG WITH MOIST NORTHERLY FLOW WILL KEEP LIFR CIGS AT SAW
OVERNIGHT. CYCLONIC UPSLOPE FLOW INTO THE NORTH CENTRAL U.P. WILL
KEEP LOW CIGS AT KSAW INTO TUESDAY AFTERNOON BEFORE DRIER AIR AND
VFR CONDITIONS ARRIVE LATE TUE AFTERNOON.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 447 AM EDT MON AUG 11 2014
A COLD FRONT WILL MOVE ACROSS THE LAKE TODAY. BEHIND THE COLD
FRONT...NORTH WINDS WILL INCREASE MON AND GUST TO MORE THAN 20 KT
MON NIGHT INTO TUE...PRODUCING WAVES UP TO 7 FT OVER THE CENTRAL AND
EASTERN LAKE. HIGH PRESSURE BUILDING INTO THE AREA BY WED NIGHT WILL
ALLOW WINDS TO ONCE AGAIN SUBSIDE TO BELOW 15 KT BY MID WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
BEACH HAZARDS STATEMENT FROM 8 AM EDT THIS MORNING THROUGH THIS
EVENING FOR MIZ005-006.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...MZ
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
305 AM EDT TUE AUG 12 2014
.SHORT TERM...TODAY AND TONIGHT
HIGH AMPLITUDE MID LEVEL TROUGH NOW SHIFTING ACROSS THE UPPER
MISSISSIPPI VALLEY WILL STEADILY DEEPEN AND EVENTUALLY CLOSE OFF
HEADING INTO TODAY AS IT PIVOTS ACROSS THE LOWER PENINSULA. LEAD
SPOKE OF VORTICITY ANCHORING THE EDGE OF THE MAIN HEIGHT FALL CENTER
CURRENTLY EJECTING ACROSS THE CHICAGO AREA...AND WILL PROVIDE THE
INITIAL WING OF FORCING AS IT TRANSLATES ACROSS MAINLY THE SOUTHERN
HALF OF THE FORECAST AREA EARLY IN THE DAY. THIS MAY PROVE
SUFFICIENT TOWARD SPARKING A FEW SHOWERS...LATEST HI RES GUIDANCE
AND RUC ANALYSIS IN SUPPORT OF A LOW POP MENTION EARLY ON. GREATEST
PROSPECTS FOR PRECIPITATION DEVELOPMENT WILL FOCUS INTO THE
AFTERNOON/EARLY EVENING AS LAPSE RATES STEEPEN CONSIDERABLY THROUGH
BOTH DAYTIME HEATING AND THE PASSAGE OF THE ATTENDANT COLD POOL
/-13C AT 500 MB/. A PERIOD OF GREATER CVA ACCOMPANYING THE MAIN
TROUGH PASSAGE WILL PROVIDE THE BACKGROUND FORCING TO SUPPORT A
SCATTERED COVERAGE OF SHOWERS AND THUNDERSTORMS GIVEN THE
THERMODYNAMIC PROFILE. THE OVERALL TEMPERATURE RECOVERY WILL BE
HINDERED BY LESS FAVORABLE INSOLATION POTENTIAL WITH CLOUD COVER
PROBLEMATIC. HIGHS IN THE LOW AND MIDDLE 70S.
LOW LEVEL COLD AIR ADVECTION TONIGHT AS DEEPER NORTHWEST FLOW
EMERGES ON THE BACKSIDE OF THE EXITING TROUGH. THE BETTER LOW LEVEL
DRYING WILL TAKE MORE TIME TO DEVELOP...NOTING THE SUBSTANTIAL LOW
CLOUD STILL EMANATING ACROSS THE MISSISSIPPI VALLEY THIS MORNING.
THIS POINTS TOWARD SOME LINGERING LOWER STRATUS FOR MUCH OF THE
OVERNIGHT PERIOD...A MORE GRADUALLY CLEARING TREND CLOSER TO
DAYBREAK. LOWS IN THE 50S.
&&
.LONG TERM...
TODAY`S SYSTEM WILL PHASE WITH ENERGY DIVING INTO ONTARIO THIS
MORNING TO PRODUCE A LARGE CLOSED LOW CENTERED OVER WESTERN QUEBEC
BY EARLY THURSDAY. AS A RESULT, DRY NORTHWEST FLOW IS FORECAST TO
DOMINATE OVER THE CENTRAL GREAT LAKES FOR THE REMAINDER OF THE WEEK.
WHILE EMBEDDED IMPULSES WITHIN PREVAILING CYCLONIC FLOW ALOFT WILL
PROPAGATE ACROSS THE AREA BOTH WED AND THURS, DEEP MOISTURE WILL
REMAIN WRAPPED AROUND THE OCCLUDING SURFACE LOW. THIS WILL ELIMINATE
CONCERNS FOR PRECIPITATION AND WILL SHIFT THE FOCUS TOWARD CLOUD
COVER EACH DAY. THE LARGEST CHANGE TO THE INHERITED FORECAST WAS TO
BUMP UP AFTN CLOUD COVER BOTH WED AND THURS GIVEN THE PROGGED
FAVORABLE TIMING OF UPPER WAVES WITH PEAK HEATING AND HIGHER
EXPECTATIONS FOR RESIDENT BOUNDARY LAYER MOISTURE GIVEN THE
COMBINATION OF YESTERDAY`S AND TODAY`S RAINFALL.
H85 TEMPS AROUND 10C COMBINED WITH CLOUDS WILL SUPPORT HIGHS IN MOST
PLACES NO BETTER THAN THE MID 70S ON WEDNESDAY. THE AFOREMENTIONED
PASSING UPPER WAVE WILL ORGANIZE A WEAK BAROCLINIC ZONE THAT WILL
PUSH SOUTH THROUGH THE CWA WEDNESDAY NIGHT. WITH H85 TEMPS TAKING
ANOTHER DIVE TO AROUND 6C THURSDAY, HIGHS WILL TOP OUT IN THE LOW
70S, PERHAPS ONLY REACHING THE UPPER 60S THE EASTERN THUMB AND ALONG
THE GLACIAL RIDGE.
EASTWARD PROGRESSION OF THE UPSTREAM UPPER RIDGE WILL FORCE SURFACE
HIGH PRESSURE TO TRANSLATE EASTWARD AND ULTIMATELY SETTLE JUST SOUTH
OF THE AREA ON THURSDAY NIGHT. EASING OF THE LOCAL PRESSURE GRADIENT
WILL RESULT MORE FAVORABLE RADIATING CONDITIONS. AS A RESULT,
DROPPED FORECAST HIGHS SEVERAL DEGREES INTO THE MID 40S OUTSIDE OF
THE METRO AREA. SUSPECT THAT THERE WILL STILL BE ENOUGH BOUNDARY
LAYER MOISTURE HANGING AROUND TO MAKE FOG A CONSIDERATION FOR
THURSDAY NIGHT, BUT WILL REFRAIN FROM INTRODUCING IT INTO THE
FORECAST AT SUCH AN EARLY STAGE. HIGHS WILL REBOUND INTO THE MID 70S
ON FRIDAY IN RESPONSE TO THE DEPARTURE OF THE THERMAL TROUGH.
&&
.MARINE...
A FRESH NORTHWEST BREEZE WILL GUST TO NEAR GALES ACROSS THE NORTHERN
HALF OF LAKE HURON LATE THIS AFTERNOON THROUGH THE FIRST HALF OF
TONIGHT AS COLDER AIR FILTERS INTO THE REGION. MARGINAL SMALL CRAFT
ADVISORY CONDITIONS WILL THEREFORE BE POSSIBLE LATE TONIGHT INTO
EARLY WEDNESDAY FOR THE EXPOSED NEARSHORE WATERS OF THE THUMB.
SURFACE HIGH PRESSURE WILL REMAIN UPSTREAM OF THE AREA WHICH WILL
PROMOTE A STEADY STATE MODERATE NORTHWEST FLOW THROUGH THURSDAY
NIGHT. GUSTS IN EXCESS OF 20 KNOTS WILL REMAIN COMMON OVER LAKE
HURON DURING THIS TIME. WINDS WILL EASE A BIT ON FRIDAY AS THE
CENTER OF HIGH PRESSURE SETTLES CLOSER TO THE REGION.
&&
.AVIATION...ISSUED 1202 AM EDT TUE AUG 12 2014
//DISCUSSION...
HEAVY RAIN HAS EXITED THE TAF SITES. HOWEVER RESIDUAL LOW LEVEL
MOISTURE HAS LED TO THE FORMATION OF LOW CEILINGS AND RESTRICTIONS
TO VISIBILITY. WIDESPREAD IFR CONDITIONS ARE EXPECTED
OVERNIGHT...WITH POCKETS OF LIFR POSSIBLE. INCREASING SOUTHWEST TO
WESTERLY GRADIENT TUESDAY MORNING AND THE COMMENCEMENT OF THE
DAYLIGHT SHOULD ALLOW CLOUD BASES TO RISE BACK INTO THE MVFR
CATEGORY. WRAP AROUND MOISTURE FROM A DEPARTING LOW PRESSURE SYSTEM
WILL BRING MORE RAIN TO THE TAF SITES LATE TUESDAY MORNING INTO THE
AFTERNOON HOURS...WITH THE BEST CHANCES NORTH OF THE METRO AIRPORTS.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILINGS BELOW 5000 FEET THROUGH TUESDAY.
* LOW CONFIDENCE IN CEILINGS/VSBYS FALLING BELOW 200FT/1/2SM
OVERNIGHT WITH FOG.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...MR
LONG TERM....JVC
MARINE.......JVC
AVIATION.....KURIMSKI
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
130 AM EDT TUE AUG 12 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 410 PM EDT MON AUG 11 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE OVER
THE ROCKIES AND A TROUGH FROM HUDSON BAY INTO THE UPPER MS VALLEY.
AT THE SFC...A FRONT EXTENDED FROM SE LAKE SUPERIOR INTO NE WI. A
DEEPENING TROUGH WITH AN 85 KNOT 250 MB JET MOVING THROUGH WRN
WI...AND 800-600 MB FGEN SUPPORTED A LARGE ARA OF PCPN THROUGH WRN
UPPER MI. ANOTHER AREA OF SHOWERS INTO SE AND ERN UPPER MI WAS
ASSOCIATED WITH A WEAK SHRTWV TROUGH INTO NRN LAKE MI.
TONIGHT...EXPECT SHRA COVERAGE TO GRADUALLY INCREASE OVER CNTRL
UPPER MI AS THE WEAKENING FGEN FORCING SHIFTS TO THE EAST. WITH
MINIMAL/SKINNY MUCAPE AOB 400 J/KG AND NO TSRA OBSERVED TODAY...ONLY
SLIGHT CHANCE TSRA WAS RETAINED THROUGH THIS EVENING. AS THE TROUGH
CONTINUED TO DEEPEN AND LOW PRES OVER WRN LOWER MI LIFTS TO LAKE
HURON...NRLY FLOW WILL STRENGTHEN ACROSS UPPER MI. THE COMBINATION OF
THE MID LEVEL FORCING AND INCREASED ONSHORE/UPSLOPE FLOW WILL ALSO
BRING AN INCREASE IN LIGHT RAIN OR DRIZZLE INTO N CNTRL UPPER MI
OVERNIGHT.
TUE...AREAS OF LIGHT RAIN OR DRIZZLE MAY CONTINUE IN THE MORNING
THROUGH N CNTRL UPPER AND E UPPER MI AND GRADUALLY DIMINISH INTO THE
AFTERNOON AS THE DEEP MOISTURE FINALLY SLIDES TO THE EAST...PER NAM
850-700 MB RH FCST. OTHERWISE...COOLER CONDITIONS ARE EXPECTED WITH
BRISK NRLY WINDS KEEPING TEMPS IN THE 60S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 358 PM EDT MON AUG 11 2014
A 500MB LOW PRESSURE TROUGH OVER THE GREAT LAKES TUESDAY EVENING
WILL DEVELOP INTO A CUT OFF LOW OVER THE LOWER LAKES THURSDAY
MORNING...THEN LIFT INTO QUEBEC BY FRIDAY EVENING. AT THE
SURFACE...LOW PRESSURE OVER LAKE HURON WILL LIFT NORTHEASTWARD INTO
QUEBEC THROUGH WEDNESDAY EVENING. AS A RESULT...ONLY HAVE LINGERING
POPS FAR EAST CLOSEST TO THE LOW THROUGH WEDNESDAY EVENING. SOME OF
THE MODELS GENERATE PRECIPITATION WITH A SHORTWAVE THAT SWINGS
AROUND THE LOW ON WEDNESDAY AFTERNOON AND EVENING...BUT THINK THIS
MAY BE OVERDOING IT AS DRY AIR WILL START TO CREEP INTO THE AREA.
KEPT WEATHER ON WEDNESDAY DRY FOR NOW...BUT BUMPED UP SKY COVER WEST
AND ALONG THE WI BORDER AS WELL. WITH A STRONGER PRESSURE GRADIENT
ACROSS THE EASTERN PORTION OF LK SUPERIOR...HAVE ONSHORE/NORTHWEST
WINDS GUSTING 10 TO 20 MPH AND WAVE HEIGHTS AROUND 3 TO 4 FEET IN
ALGER COUNTY AND MAINLY FAR EASTERN MARQUETTE COUNTY NEAR LAKE
SUPERIOR. EXPECT A MODERATE SWIM RISK FOR DANGEROUS CURRENTS AND
WAVES IN THESE AREAS.
SURFACE HIGH PRESSURE MOVES FROM THE CANADIAN PRAIRIES/NORTHERN
PLAINS INTO THE GREAT LAKES BY THURSDAY AFTERNOON...SO HAVE KEPT A
SEASONABLY COOL BUT DRY FORECAST THROUGH THEN. AS THE CLOSED LOW
ALOFT MOVES FROM ONTARIO INTO QUEBEC ON FRIDAY UPPER LEVEL FLOW
BECOMES MORE ZONAL OVER UPPER MICHIGAN. THE SURFACE HIGH DRIFTS
SOUTHEASTWARD INTO THE OHIO VALLEY...MAKING WAY FOR A WEAK SURFACE
TROUGH TO DROP ACROSS NORTHERN LAKE SUPERIOR. WITH WEAK FORCING
ACROSS THE AREA...WOULDNT BE SURPRISED TO SEE ISOLATED
SHOWERS/TSTORMS ACROSS THE WESTERN AND NORTH CENTRAL PARTS OF THE
CWA. HAVE ADDED THEM IN ACCORDINGLY. THIS WEAK SURFACE TROUGH WILL
DRIVE ACROSS THE GREAT LAKES FRIDAY NIGHT INTO SATURDAY...SO HAVE
KEPT SLIGHT CHANCE POPS FOR THE WHOLE AREA.
A MORE POTENT 500MB SHORTWAVE ARRIVES SUNDAY NIGHT INTO
MONDAY...WITH THE ASSOCIATED SURFACE LOW PRESSURE CENTERED OVER
NORTHERN MN/NORTHWESTERN ONTARIO. ANOTHER SURFACE LOW DEVELOPS OVER
WI/IOWA AROUND THE SAME TIME AND MERGES WITH THE OTHER LOW OVER LAKE
SUPERIOR BY MONDAY EVENING. MODELS ARE IN SOMEWHAT OF A DISAGREEMENT
OVER THIS...AS USUAL WITH MERGING SYSTEMS/SHORTWAVES. HAVE KEPT
CONSENSUS CHANCE/SLIGHT CHANCE POPS FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY EVENING)
ISSUED AT 130 AM EDT TUE AUG 12 2014
MVFR CONDITIONS WILL CONTINUE AT IWD AND CMX OVERNIGHT BEFORE DRIER
AIR MOVES IN FOR TUE MORNING AND LEADS TO VFR CONDITIONS THROUGH THE
REST OF THE PERIOD.
RAIN ALONG WITH MOIST NORTHERLY FLOW WILL KEEP LIFR CIGS AT SAW
OVERNIGHT. CYCLONIC UPSLOPE FLOW INTO THE NORTH CENTRAL U.P. WILL
KEEP LOW CIGS AT KSAW INTO TUESDAY AFTERNOON BEFORE DRIER AIR AND
VFR CONDITIONS ARRIVE LATE TUE AFTERNOON.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 447 AM EDT MON AUG 11 2014
A COLD FRONT WILL MOVE ACROSS THE LAKE TODAY. BEHIND THE COLD
FRONT...NORTH WINDS WILL INCREASE MON AND GUST TO MORE THAN 20 KT
MON NIGHT INTO TUE...PRODUCING WAVES UP TO 7 FT OVER THE CENTRAL AND
EASTERN LAKE. HIGH PRESSURE BUILDING INTO THE AREA BY WED NIGHT WILL
ALLOW WINDS TO ONCE AGAIN SUBSIDE TO BELOW 15 KT BY MID WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MCD
AVIATION...07
MARINE...MZ
AREA FORECAST DISCUSSION
NWS RALEIGH NC
330 AM EDT TUE AUG 12 2014
.SYNOPSIS...A WARM FRONT WILL LIFT NORTH THROUGH THE AREA THIS
MORNING. A COLD FRONT WILL CROSS THE AREA TONIGHT AND EARLY
WEDNESDAY MORNING...FOLLOWED BY HIGH PRESSURE AND DRIER WEATHER FOR
THE BALANCE OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM TUESDAY...
A FEW PATCHES OF LIGHT RAIN ARE CURRENTLY MOVING NORTHEAST THROUGH
THE PIEDMONT...THOUGH THE COVERAGE HAS DECREASED SIGNIFICANTLY SINCE
MIDNIGHT. HIGH PRESSURE OFF THE NEW ENGLAND COAST CONTINUES TO LOSE
ITS INFLUENCE...THOUGH A WEAK LOW OFF THE WILMINGTON COAST IS
HELPING TO MAINTAIN A MORE EASTERLY FLOW OVER CENTRAL NC. RAP
ISENTROPIC ANALYSIS SHOWS THE DEEPER ISENTROPIC LIFT MOVING NORTH
INTO VA...WITH SHALLOW SOUTHEASTERLY FLOW AND UPSLOPE FLOW DRIVING
THE SHOWERS OVER WESTERN NC. RAP VORT FIELDS AND WATER VAPOR
IMAGERY SUGGEST THERE MAY BE A WEAK DISTURBANCE OVER NORTHERN
GEORGIA/UPSTATE SC THAT MAY BE AIDING THESE SHOWERS. THE BULK OF
THIS PRECIP SHOULD STAY JUST TO THE WEST OF THE YADKIN RIVER THROUGH
SUNRISE...BUT SOME LIGHT RAIN WILL LIKELY KEEP THE LINGERING CAD
AIRMASS IN PLACE DESPITE THE LACK OF A STRONG STABLE LAYER OVER THE
WESTERN PIEDMONT...PER 00Z KGSO AND RAP SOUNDINGS.
MEANWHILE...THE FRONTAL ZONE WILL MOVE NORTH THROUGH THE AREA THIS
MORNING....ESPECIALLY AS MIXING INCREASES AND SOME PARTIAL BREAKS IN
CLOUD COVER DEVELOP OVER THE COASTAL PLAIN. AS TEMPS RISE INTO THE
MID TO UPPER 80S...DEWPOINTS IN THE LOWER 70S AND PW AROUND 2 INCHES
WILL LEAD TO MLCAPE OF AT LEAST 1000-1500 J/KG EAST OF THE TRIAD.
THE DEGREE OF DESTABILIZATION IF A LITTLE MORE UNCERTAIN OVER THE
NORTHWEST PIEDMONT...BUT EVEN HIGHER RES GUIDANCE SHOWS THE TRIAD
MIXING OUT BY AROUND NOON. DEEP LAYER SHEAR ISNT OVERLY IMPRESSIVE
WELL OUT AHEAD OF THE UPPER TROUGH AND ASSOCIATED COLD FRONT...WITH
AROUND 25-30KT OVER WESTERN NC...WHICH MAY BE DISPLACED FROM THE
STRONGEST INSTABILITY. THUS...WITH MAINLY CONFLUENT PRE-FRONTAL
FLOW AS THE FORCING THIS AFTERNOON ...THE COVERAGE OF STRONGER
STORMS IS STILL A LITTLE UNCERTAIN. HEAVY RAIN...EXACERBATED BY
RECENT RAINFALL OF 3-5 INCHES IN SOME AREAS...AND STRONG WIND GUSTS
WILL BE THE MAIN THREAT FROM ANY STRONGER CLUSTERS OF STORMS.
AFTERNOON HIGHS SHOULD RANGE FROM THE LOWER 80S NORTHWEST TO UPPER
80S SOUTHEAST.
THE UPPER TROUGH AND ASSOCIATED MODEST HEIGHT FALLS (FOR AUGUST) AND
DCVA WILL ENCROACH ON THE AREA LATE THIS EVENING AND
OVERNIGHT...WITH HE ATTENDANT COLD FRONT PROGGED TO CROSS THE AREA
AFTER MIDNIGHT. FORECAST SOUNDINGS SHOW SOME INSTABILITY OVERNIGHT
AHEAD OF THE FRONT...AND GIVEN THE UPPER FORCING...IT IS PLAUSIBLE
THAT THERE COULD BE ANOTHER BAND OF SHOWERS AND ISOLATED THUNDER
STORMS WITH THE COLD FRONT. DUE TO THE DRYING ALOFT...NOT QUITE
CONFIDENT ENOUGH FOR A CHANCE POP OVERNIGHT...BUT WILL SHOW A
SECONDARY SLIGHT CHANCE AREA WITH THE COLD FRONT. OVERNIGHT LOWS
WILL STILL BE MUGGY IN THE UPPER 60S TO LOWER 70S.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 325 AM TUESDAY...
THE COLD FRONT WILL MOVE TOWARD THE COAST WEDNESDAY MORNING...AS
MUCH DRIER AIR OVERSPREADS THE AREA AND PW DROPS BELOW ONE INCH.
FORECAST SOUNDINGS SHOWS A STRENGTHENING SUBSIDENCE INVERSION ALL THE
WAY EAST TO KRWI AND KFAY...SO ANY ADDITIONAL SHOWERS IN THE
VICINITY OF THE FRONT WILL BE CONFINED TO THE COAST. HIGHS WILL
STILL BE IN THE 83-89 RANGE...BUT THE BIGGER CHANGE WILL BE IN
DEWPOINTS AND THEY FALL INTO THE 50S FROM NORTHWEST TO SOUTHEAST
DURING THE AFTERNOON. THIS WILL ALSO LEAD TO COOLER LOWS...60-
65...AS THICKNESSES DIP BELOW 1390M BY THURSDAY MORNING.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 315 AM TUESDAY...
LITTLE CHANGE IN OVERALL FORECAST RATIONALE FROM THE PAST COUPLE OF
DAYS. THROUGH DAY 5...DETERMINISTIC AND ENSEMBLE MEAN MEDIUM RANGE
GUIDANCE SOLUTIONS ARE IN RELATIVELY GOOD AGREEMENT AND ARE
CHARACTERIZED BY A RELATIVELY HIGH AMPLITUDE RIDGE OVER INTERIOR
WESTERN NOAM...FLANKED BY A COUPLE OF SLOWLY ENE-MIGRATING AND
FILLING UPPER LOWS ACROSS THE NW AND NE CORNERS OF THE CONUS. THE
ASSOCIATED ANOMALOUSLY LOW HEIGHTS ALOFT FROM SOUTHEASTERN CANADA TO
THE CAROLINAS WILL RELAX AND PROMOTE GRADUALLY WARMING CONDITIONS
FRI INTO THE WEEKEND. MODEL SPREAD INCREASES FOR DAYS 6-7...MOST
NOTABLY WITH THE HANDLING OF A SHORTWAVE TROUGH FORECAST TO SETTLE
INTO THE MID-UPPER MS VALLEY EARLY NEXT WEEK. DIFFERENCES WITH THE
HANDLING OF THIS FEATURE ARISE SEEMINGLY IN PART DUE TO THE DEGREE
OF DOWNSTREAM RE-DEVELOPMENT OF A NEGATIVE HEIGHT ANOMALY OVER THE
NE CONUS (IF ANY) - WHICH WOULD EFFECTIVELY SLOW THE PROGRESSION OF
THE FLOW AND EMBEDDED SHORTWAVES UPSTREAM. THE 12Z/11TH EC ENSEMBLE
MEAN PROVIDES A REASONABLE COMPROMISE SOLUTION BETWEEN THE 00Z/12TH
DETERMINISTIC ECMWF (OUTLIER) THAT IS MOST AGGRESSIVE WITH THE RE-
DEVELOPMENT OF THE VORTEX OVER THE NE...VERSUS THE PAST COUPLE OF
RUNS OF THE GFS THAT DEPICT NO RE-DEVELOPMENT WHATSOEVER.
THU THROUGH SUN: A LEAD CANADIAN HIGH WILL BUILD SOUTH INTO THE MID
MS VALLEY THU...AND AWAIT UPSTREAM REINFORCEMENT FROM A REINFORCING
COLD FRONT/CANADIAN HIGH FORECAST TO SETTLE SOUTH ACROSS THE OH AND
TN VALLEYS THROUGH FRI. THOUGH MASKED BY WEAK LEESIDE SFC TROUGHING
IN THE LEE OF THE APPALACHIANS...BENEATH CYCLONIC FLOW ALOFT AND
ASSOCIATED LOW-MID LEVEL WESTERLY (DOWNSLOPE) FLOW...THE CENTER OF
THE CANADIAN HIGH WILL BUILD INTO AND ACROSS THE CENTRAL
APPALACHIANS THROUGH SAT. MOISTURE...AT THE SFC AND THROUGH A DEEP
LAYER...WILL CONSEQUENTLY BE LIMITED. IN FACT...THE RELATIVE DRYNESS
WILL BE HIGHLIGHTED BY SFC DEWPOINTS IN THE 50S AND PRECIPITABLE
WATER VALUES AOB ONE INCH ON THU...BOTH OF WHICH ONLY SLOWLY
INCREASE AND RESULT IN PRIMARILY SEA BREEZE AND MOUNTAIN-INDUCED
CONVECTION...THROUGH THE WEEKEND. WILL INTRODUCE A SLIGHT CHANCE OF
A DIURNALLY-DRIVEN AFTERNOON STORM OVER THE SOUTHERN COASTAL PLAIN
TO ACCOUNT FOR SOME SEA-BREEZE CONVECTION/OUTFLOW PROPAGATING AWAY
FROM COASTAL AREAS.
OTHERWISE...H85 TEMPS INITIALLY IN THE 14-16C RANGE...SHOULD SUPPORT
TEMPERATURES PERHAPS NEAR TO SLIGHTLY BELOW NORMAL THROUGH
FRI...WITH WARMING TO AROUND OR SLIGHTLY ABOVE NORMAL VALUES THROUGH
EARLY NEXT WEEK. THE EVOLUTION OF THE AFOREMENTIONED SHORTWAVE
TROUGH SETTLING ACROSS THE MS VALLEY EARLY NEXT WEEK WOULD FOCUS
ABOVE NORMAL PRECIPITATION CHANCES WEST OF THE APPALACHIANS/OVER THE
OH VALLEY THROUGH DAY 7.
&&
.AVIATION /06Z MONDAY THROUGH SATURDAY/...
AS OF 130 AM TUESDAY...
A FEW AREAS OF RAIN CONTINUE TO MOVE SLOWLY NORTHEAST ACROSS THE
PIEDMONT...THOUGH GENERALLY CLEAR OF THE TAF SITES. MAY SEE ANOTHER
ROUND OF LIGHT TO MODERATE RAIN AT KRDU BY 08Z.
MEANWHILE...CEILINGS ARE ALREADY AT LIFR/IFR LEVELS AT
KINT/KGSO...AND WILL CONTINUE TO LOWER AT KRDU/KFAY/KRWI BY 09Z.
CONFIDENCE IN IFR CONDITIONS IS LOWEST AT KRWI HOWEVER...SO WILL
JUST KEEP A TEMPO FOR NOW. SCATTERING OF LOW CLOUDS WILL OCCUR
DURING THE MID-MORNING HOURS AS A WARM FRONT LIFTS THROUGH THE
AREA...FIRST AT KFAY AND KRWI. STRATUS WILL LIKELY HAND AROUND
LONGER AT KGSO/KINT...POSSIBLY UNTIL AROUND 16Z. WITH AT LEAST
PARTIAL CLEARING...HEATING AND DESTABILIZATION WILL SUPPORT SCATTERED
SHOWERS AND STORMS DURING THE AFTERNOON. CONFIDENCE IN TIMING OF
IMPACT AT TERMINALS IS TOO LOW FOR MENTION OF THUNDER IN TAFS...BUT
PROBABILITIES ARE GREATER AT KRDU/KFAY/KRWI. EXPECT AT LEAST MFR
CEILINGS IN THE TRIAD...IF NOT EVENTUALLY VFR EVERYWHERE DURING THE
AFTERNOON.
A COLD FRONT WILL APPROACH FROM THE WEST DURING THE
EVENING...NEARING KGSO AND KINT BY THE END OF THE CURRENT TAF
PERIOD. ADDITIONAL SHOWERS/STORMS MAY BE POSSIBLE WITH THE FRONT
AFTER 06Z.
OUTLOOK...ONCE THE COLD FRONT CLEARS THE AREA WEDNESDAY
MORNING...VFR CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...BLS
SHORT TERM...BLS
LONG TERM...MWS
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
320 AM EDT TUE AUG 12 2014
.SYNOPSIS...A WARM FRONT WILL LIFT NORTH THROUGH THE AREA THIS
MORNING. A COLD FRONT WILL CROSS THE AREA TONIGHT AND EARLY
WEDNESDAY MORNING...FOLLOWED BY HIGH PRESSURE AND DRIER WEATHER FOR
THE BALANCE OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM MONDAY...
A FEW PATCHES OF LIGHT RAIN ARE CURRENTLY MOVING NORTHEAST THROUGH
THE PIEDMONT...THOUGH THE COVERAGE HAS DECREASED SIGNIFICANTLY SINCE
MIDNIGHT. HIGH PRESSURE OFF THE NEW ENGLAND COAST CONTINUES TO LOSE
ITS INFLUENCE...THOUGH A WEAK LOW OFF THE WILMINGTON COAST IS
HELPING TO MAINTAIN A MORE EASTERLY FLOW OVER CENTRAL NC. RAP
ISENTROPIC ANALYSIS SHOWS THE DEEPER ISENTROPIC LIFT MOVING NORTH
INTO VA...WITH SHALLOW SOUTHEASTERLY FLOW AND UPSLOPE FLOW DRIVING
THE SHOWERS OVER WESTERN NC. RAP VORT FIELDS AND WATER VAPOR
IMAGERY SUGGEST THERE MAY BE A WEAK DISTURBANCE OVER NORTHERN
GEORGIA/UPSTATE SC THAT MAY BE AIDING THESE SHOWERS. THE BULK OF
THIS PRECIP SHOULD STAY JUST TO THE WEST OF THE YADKIN RIVER THROUGH
SUNRISE...BUT SOME LIGHT RAIN WILL LIKELY KEEP THE LINGERING CAD
AIRMASS IN PLACE DESPITE THE LACK OF A STRONG STABLE LAYER OVER THE
WESTERN PIEDMONT...PER 00Z KGSO AND RAP SOUNDINGS.
MEANWHILE...THE FRONTAL ZONE WILL MOVE NORTH THROUGH THE AREA THIS
MORNING....ESPECIALLY AS MIXING INCREASES AND SOME PARTIAL BREAKS IN
CLOUD COVER DEVELOP OVER THE COASTAL PLAIN. AS TEMPS RISE INTO THE
MID TO UPPER 80S...DEWPOINTS IN THE LOWER 70S AND PW AROUND 2 INCHES
WILL LEAD TO MLCAPE OF AT LEAST 1000-1500 J/KG EAST OF THE TRIAD.
THE DEGREE OF DESTABILIZATION IF A LITTLE MORE UNCERTAIN OVER THE
NORTHWEST PIEDMONT...BUT EVEN HIGHER RES GUIDANCE SHOWS THE TRIAD
MIXING OUT BY AROUND NOON. DEEP LAYER SHEAR ISNT OVERLY IMPRESSIVE
WELL OUT AHEAD OF THE UPPER TROUGH AND ASSOCIATED COLD FRONT...WITH
AROUND 25-30KT OVER WESTERN NC...WHICH MAY BE DISPLACED FROM THE
STRONGEST INSTABILITY. THUS...WITH MAINLY CONFLUENT PRE-FRONTAL
FLOW AS THE FORCING THIS AFTERNOON ...THE COVERAGE OF STRONGER
STORMS IS STILL A LITTLE UNCERTAIN. HEAVY RAIN...EXACERBATED BY
RECENT RAINFALL OF 3-5 INCHES IN SOME AREAS...AND STRONG WIND GUSTS
WILL BE THE MAIN THREAT FROM ANY STRONGER CLUSTERS OF STORMS.
AFTERNOON HIGHS SHOULD RANGE FROM THE LOWER 80S NORTHWEST TO UPPER
80S SOUTHEAST.
THE UPPER TROUGH AND ASSOCIATED MODEST HEIGHT FALLS (FOR AUGUST) AND
DCVA WILL ENCROACH ON THE AREA LATE THIS EVENING AND
OVERNIGHT...WITH HE ATTENDANT COLD FRONT PROGGED TO CROSS THE AREA
AFTER MIDNIGHT. FORECAST SOUNDINGS SHOW SOME INSTABILITY OVERNIGHT
AHEAD OF THE FRONT...AND GIVEN THE UPPER FORCING...IT IS PLAUSIBLE
THAT THERE COULD BE ANOTHER BAND OF SHOWERS AND ISOLATED THUNDER
STORMS WITH THE COLD FRONT. DUE TO THE DRYING ALOFT...NOT QUITE
CONFIDENT ENOUGH FOR A CHANCE POP OVERNIGHT...BUT WILL SHOW A
SECONDARY SLIGHT CHANCE AREA WITH THE COLD FRONT. OVERNIGHT LOWS
WILL STILL BE MUGGY IN THE UPPER 60S TO LOWER 70S.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 300 PM MONDAY...
UPDATED SHORTLY...
&&
.LONG TERM THURSDAY THROUGH MONDAY/...
AS OF 315 AM TUESDAY...
LITTLE CHANGE IN OVERALL FORECAST RATIONALE FROM THE PAST COUPLE OF
DAYS. THROUGH DAY 5...DETERMINISTIC AND ENSEMBLE MEAN MEDIUM RANGE
GUIDANCE SOLUTIONS ARE IN RELATIVELY GOOD AGREEMENT AND ARE
CHARACTERIZED BY A RELATIVELY HIGH AMPLITUDE RIDGE OVER INTERIOR
WESTERN NOAM...FLANKED BY A COUPLE OF SLOWLY ENE-MIGRATING AND
FILLING UPPER LOWS ACROSS THE NW AND NE CORNERS OF THE CONUS. THE
ASSOCIATED ANOMALOUSLY LOW HEIGHTS ALOFT FROM SOUTHEASTERN CANADA TO
THE CAROLINAS WILL RELAX AND PROMOTE GRADUALLY WARMING CONDITIONS
FRI INTO THE WEEKEND. MODEL SPREAD INCREASES FOR DAYS 6-7...MOST
NOTABLY WITH THE HANDLING OF A SHORTWAVE TROUGH FORECAST TO SETTLE
INTO THE MID-UPPER MS VALLEY EARLY NEXT WEEK. DIFFERENCES WITH THE
HANDLING OF THIS FEATURE ARISE SEEMINGLY IN PART DUE TO THE DEGREE
OF DOWNSTREAM RE-DEVELOPMENT OF A NEGATIVE HEIGHT ANOMALY OVER THE
NE CONUS (IF ANY) - WHICH WOULD EFFECTIVELY SLOW THE PROGRESSION OF
THE FLOW AND EMBEDDED SHORTWAVES UPSTREAM. THE 12Z/11TH EC ENSEMBLE
MEAN PROVIDES A REASONABLE COMPROMISE SOLUTION BETWEEN THE 00Z/12TH
DETERMINISTIC ECMWF (OUTLIER) THAT IS MOST AGGRESSIVE WITH THE RE-
DEVELOPMENT OF THE VORTEX OVER THE NE...VERSUS THE PAST COUPLE OF
RUNS OF THE GFS THAT DEPICT NO RE-DEVELOPMENT WHATSOEVER.
THU THROUGH SUN: A LEAD CANADIAN HIGH WILL BUILD SOUTH INTO THE MID
MS VALLEY THU...AND AWAIT UPSTREAM REINFORCEMENT FROM A REINFORCING
COLD FRONT/CANADIAN HIGH FORECAST TO SETTLE SOUTH ACROSS THE OH AND
TN VALLEYS THROUGH FRI. THOUGH MASKED BY WEAK LEESIDE SFC TROUGHING
IN THE LEE OF THE APPALACHIANS...BENEATH CYCLONIC FLOW ALOFT AND
ASSOCIATED LOW-MID LEVEL WESTERLY (DOWNSLOPE) FLOW...THE CENTER OF
THE CANADIAN HIGH WILL BUILD INTO AND ACROSS THE CENTRAL
APPALACHIANS THROUGH SAT. MOISTURE...AT THE SFC AND THROUGH A DEEP
LAYER...WILL CONSEQUENTLY BE LIMITED. IN FACT...THE RELATIVE DRYNESS
WILL BE HIGHLIGHTED BY SFC DEWPOINTS IN THE 50S AND PRECIPITABLE
WATER VALUES AOB ONE INCH ON THU...BOTH OF WHICH ONLY SLOWLY
INCREASE AND RESULT IN PRIMARILY SEA BREEZE AND MOUNTAIN-INDUCED
CONVECTION...THROUGH THE WEEKEND. WILL INTRODUCE A SLIGHT CHANCE OF
A DIURNALLY-DRIVEN AFTERNOON STORM OVER THE SOUTHERN COASTAL PLAIN
TO ACCOUNT FOR SOME SEA-BREEZE CONVECTION/OUTFLOW PROPAGATING AWAY
FROM COASTAL AREAS.
OTHERWISE...H85 TEMPS INITIALLY IN THE 14-16C RANGE...SHOULD SUPPORT
TEMPERATURES PERHAPS NEAR TO SLIGHTLY BELOW NORMAL THROUGH
FRI...WITH WARMING TO AROUND OR SLIGHTLY ABOVE NORMAL VALUES THROUGH
EARLY NEXT WEEK. THE EVOLUTION OF THE AFOREMENTIONED SHORTWAVE
TROUGH SETTLING ACROSS THE MS VALLEY EARLY NEXT WEEK WOULD FOCUS
ABOVE NORMAL PRECIPITATION CHANCES WEST OF THE APPALACHIANS/OVER THE
OH VALLEY THROUGH DAY 7.
&&
.AVIATION /06Z MONDAY THROUGH SATURDAY/...
AS OF 130 AM TUESDAY...
A FEW AREAS OF RAIN CONTINUE TO MOVE SLOWLY NORTHEAST ACROSS THE
PIEDMONT...THOUGH GENERALLY CLEAR OF THE TAF SITES. MAY SEE ANOTHER
ROUND OF LIGHT TO MODERATE RAIN AT KRDU BY 08Z.
MEANWHILE...CEILINGS ARE ALREADY AT LIFR/IFR LEVELS AT
KINT/KGSO...AND WILL CONTINUE TO LOWER AT KRDU/KFAY/KRWI BY 09Z.
CONFIDENCE IN IFR CONDITIONS IS LOWEST AT KRWI HOWEVER...SO WILL
JUST KEEP A TEMPO FOR NOW. SCATTERING OF LOW CLOUDS WILL OCCUR
DURING THE MID-MORNING HOURS AS A WARM FRONT LIFTS THROUGH THE
AREA...FIRST AT KFAY AND KRWI. STRATUS WILL LIKELY HAND AROUND
LONGER AT KGSO/KINT...POSSIBLY UNTIL AROUND 16Z. WITH AT LEAST
PARTIAL CLEARING...HEATING AND DESTABILIZATION WILL SUPPORT SCATTERED
SHOWERS AND STORMS DURING THE AFTERNOON. CONFIDENCE IN TIMING OF
IMPACT AT TERMINALS IS TOO LOW FOR MENTION OF THUNDER IN TAFS...BUT
PROBABILITIES ARE GREATER AT KRDU/KFAY/KRWI. EXPECT AT LEAST MFR
CEILINGS IN THE TRIAD...IF NOT EVENTUALLY VFR EVERYWHERE DURING THE
AFTERNOON.
A COLD FRONT WILL APPROACH FROM THE WEST DURING THE
EVENING...NEARING KGSO AND KINT BY THE END OF THE CURRENT TAF
PERIOD. ADDITIONAL SHOWERS/STORMS MAY BE POSSIBLE WITH THE FRONT
AFTER 06Z.
OUTLOOK...ONCE THE COLD FRONT CLEARS THE AREA WEDNESDAY
MORNING...VFR CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...BLS
SHORT TERM...DJF
LONG TERM...MWS
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
315 AM EDT TUE AUG 12 2014
.SYNOPSIS...A WARM FRONT WILL LIFT NORTH THROUGH THE AREA THIS
MORNING. A COLD FRONT WILL CROSS THE AREA TONIGHT AND EARLY
WEDNESDAY MORNING...FOLLOWED BY HIGH PRESSURE AND DRIER WEATHER FOR
THE BALANCE OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM MONDAY...
A FEW PATCHES OF LIGHT RAIN ARE CURRENTLY MOVING NORTHEAST THROUGH
THE PIEDMONT...THOUGH THE COVERAGE HAS DECREASED SIGNIFICANTLY SINCE
MIDNIGHT. HIGH PRESSURE OFF THE NEW ENGLAND COAST CONTINUES TO LOSE
ITS INFLUENCE...THOUGH A WEAK LOW OFF THE WILMINGTON COAST IS
HELPING TO MAINTAIN A MORE EASTERLY FLOW OVER CENTRAL NC. RAP
ISENTROPIC ANALYSIS SHOWS THE DEEPER ISENTROPIC LIFT MOVING NORTH
INTO VA...WITH SHALLOW SOUTHEASTERLY FLOW AND UPSLOPE FLOW DRIVING
THE SHOWERS OVER WESTERN NC. RAP VORT FIELDS AND WATER VAPOR
IMAGERY SUGGEST THERE MAY BE A WEAK DISTURBANCE OVER NORTHERN
GEORGIA/UPSTATE SC THAT MAY BE AIDING THESE SHOWERS. THE BULK OF
THIS PRECIP SHOULD STAY JUST TO THE WEST OF THE YADKIN RIVER THROUGH
SUNRISE...BUT SOME LIGHT RAIN WILL LIKELY KEEP THE LINGERING CAD
AIRMASS IN PLACE DESPITE THE LACK OF A STRONG STABLE LAYER OVER THE
WESTERN PIEDMONT...PER 00Z KGSO AND RAP SOUNDINGS.
MEANWHILE...THE FRONTAL ZONE WILL MOVE NORTH THROUGH THE AREA THIS
MORNING....ESPECIALLY AS MIXING INCREASES AND SOME PARTIAL BREAKS IN
CLOUD COVER DEVELOP OVER THE COASTAL PLAIN. AS TEMPS RISE INTO THE
MID TO UPPER 80S...DEWPOINTS IN THE LOWER 70S AND PW AROUND 2 INCHES
WILL LEAD TO MLCAPE OF AT LEAST 1000-1500 J/KG EAST OF THE TRIAD.
THE DEGREE OF DESTABILIZATION IF A LITTLE MORE UNCERTAIN OVER THE
NORTHWEST PIEDMONT...BUT EVEN HIGHER RES GUIDANCE SHOWS THE TRIAD
MIXING OUT BY AROUND NOON. DEEP LAYER SHEAR ISNT OVERLY IMPRESSIVE
WELL OUT AHEAD OF THE UPPER TROUGH AND ASSOCIATED COLD FRONT...WITH
AROUND 25-30KT OVER WESTERN NC...WHICH MAY BE DISPLACED FROM THE
STRONGEST INSTABILITY. THUS...WITH MAINLY CONFLUENT PRE-FRONTAL
FLOW AS THE FORCING THIS AFTERNOON ...THE COVERAGE OF STRONGER
STORMS IS STILL A LITTLE UNCERTAIN. HEAVY RAIN...EXACERBATED BY
RECENT RAINFALL OF 3-5 INCHES IN SOME AREAS...AND STRONG WIND GUSTS
WILL BE THE MAIN THREAT FROM ANY STRONGER CLUSTERS OF STORMS.
AFTERNOON HIGHS SHOULD RANGE FROM THE LOWER 80S NORTHWEST TO UPPER
80S SOUTHEAST.
THE UPPER TROUGH AND ASSOCIATED MODEST HEIGHT FALLS (FOR AUGUST) AND
DCVA WILL ENCROACH ON THE AREA LATE THIS EVENING AND
OVERNIGHT...WITH HE ATTENDANT COLD FRONT PROGGED TO CROSS THE AREA
AFTER MIDNIGHT. FORECAST SOUNDINGS SHOW SOME INSTABILITY OVERNIGHT
AHEAD OF THE FRONT...AND GIVEN THE UPPER FORCING...IT IS PLAUSIBLE
THAT THERE COULD BE ANOTHER BAND OF SHOWERS AND ISOLATED THUNDER
STORMS WITH THE COLD FRONT. DUE TO THE DRYING ALOFT...NOT QUITE
CONFIDENT ENOUGH FOR A CHANCE POP OVERNIGHT...BUT WILL SHOW A
SECONDARY SLIGHT CHANCE AREA WITH THE COLD FRONT. OVERNIGHT LOWS
WILL STILL BE MUGGY IN THE UPPER 60S TO LOWER 70S.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 300 PM MONDAY...
UPDATED SHORTLY...
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...
A TRANQUIL WEATHER PATTERN EXPECTED IN THE LONG TERM. TEMPERATURES
WILL REMAIN NEAR OR BELOW NORMAL.
A L/W TROUGH ANCHORED BY AN UPPER LEVEL LOW OVER ONTARIO/QUEBEC WILL
EXTEND SOUTHWARD INTO THE CAROLINAS THROUGH FRIDAY. THE LEAD COLD
FRONT ASSOCIATED WITH THE TROUGH WILL EXIT OUR COASTAL PLAIN
COUNTIES WEDNESDAY MORNING. MODEL TREND HAS LEANED TOWARD A SLIGHTLY
FASTER EAST PROGRESSION. THUS HAVE TRIMMED THE BACKSIDE OF THE
SLIGHT POPS...KEEPING THE 20 PERCENT POPS CONFINED TO LOCATIONS
ALONG AND EAST OF I-95 AT 6 AM...WITH NEGLIGIBLE POPS BY 10 AM.
WESTERLY LOW LEVEL FLOW IN THE WAKE OF THE FRONT WILL AID TO
DIMINISH/DISSIPATE CLOUD COVERAGE IN THE MORNING...LEADING TO MOSTLY
SUNNY SKIES AREAWIDE BY EARLY AFTERNOON. IT SHOULD BE NOTICEABLY
LESS HUMID ACROSS MICH OF THE PIEDMONT BY EARLY-MID AFTERNOON...AND
INTO THE SANDHILLS AND COASTAL PLAIN LATE IN THE DAY. INITIAL SURGE
OF LOW LEVEL CAA WILL BE NEGATED SOMEWHAT BY DOWNSLOPE COMPONENT OF
LOW LEVEL FLOW AND MID-AUGUST SUN. MAX TEMPS IN THE MID 80S NW TO
UPPER 80S/AROUND 90 SE.
SOME DOUBT AS TO WHETHER NEAR SURFACE WINDS WILL BE ABLE TO DECOUPLE
AS A SECONDARY SFC FRONT WILL APPROACH FROM THE W-NW LATE WEDNESDAY
NIGHT-EARLY THURSDAY. IF ATMOSPHERE REMAINS WELL MIXED...MOST PLACES
SHOULD SEE MIN TEMPS NO LOWER THAN 60-65 DEGREES (NW-SE). IF WINDS
DECOUPLE...NORMALLY COLDER LOCATIONS MY DIP BELOW 60.
A CANADIAN HIGH PRESSURE SYSTEM AT THE SURFACE WILL BE CENTERED OVER
THE LOWER OH VALLEY AND TN VALLEY THURSDAY AND FRIDAY. THIS WEATHER
SYSTEM WILL MAINTAIN DRY CONDITIONS WITH TEMPS GENERALLY A FEW
DEGREES SHY OF NORMAL. THICKNESSES SUPPORT MAX TEMPS IN THE LOW-MID
80S THURSDAY...AND SOLIDLY IN THE MID 80S FRIDAY. BETTER CHANCE FOR
THE NEAR SURFACE WINDS TO DECOUPLE THURSDAY NIGHT. IF SKIES REMAIN
CLEAR...SHOULD SEE MIN TEMPS IN THE UPPER 50S-LOWER 60S. AIR MASS
MODIFICATION FRIDAY NIGHT SUGGEST MIN TEMPS IN THE LOW-MID 60S.
SURFACE HIGH PRESSURE WILL SETTLE OVERHEAD SATURDAY THEN SLOWLY
WEAKEN AS L/W TROUGH WEAKENS AND LIFTS NWD. THIS WILL ALLOW A WEAK
RETURN OF LOW LEVEL MOISTURE BY LATE SATURDAY AND MORE SO SUNDAY
INTO MONDAY. THIS WILL LEAD TO MIXTURE OF SUN/CLOUDS BUT ANY
CONVECTIVE ACTIVITY WILL BE ISOLATED AND CONFINED TO NEAR THE
SEABREEZE...AND EXITING OFF THE HIGHER TERRAIN OF WESTERN NC.
THREAT APPEARS TOO LOW TO MENTION A SLIGHT CHANCE POP ON SUNDAY BUT
ENOUGH MOISTURE/DESTABILIZATION SHOULD EXISTS BY MONDAY FOR SLIGHT
CHANCE IN VICINITY OF THE OUR SOUTHERN AND WESTERN COUNTIES.
AIR MASS WILL CONTINUE TO MODIFY WITH TEMPS RETURNING TO NEAR NORMAL
LEVELS SATURDAY THROUGH MONDAY.
&&
.AVIATION /06Z MONDAY THROUGH SATURDAY/...
AS OF 130 AM TUESDAY...
A FEW AREAS OF RAIN CONTINUE TO MOVE SLOWLY NORTHEAST ACROSS THE
PIEDMONT...THOUGH GENERALLY CLEAR OF THE TAF SITES. MAY SEE ANOTHER
ROUND OF LIGHT TO MODERATE RAIN AT KRDU BY 08Z.
MEANWHILE...CEILINGS ARE ALREADY AT LIFR/IFR LEVELS AT
KINT/KGSO...AND WILL CONTINUE TO LOWER AT KRDU/KFAY/KRWI BY 09Z.
CONFIDENCE IN IFR CONDITIONS IS LOWEST AT KRWI HOWEVER...SO WILL
JUST KEEP A TEMPO FOR NOW. SCATTERING OF LOW CLOUDS WILL OCCUR
DURING THE MID-MORNING HOURS AS A WARM FRONT LIFTS THROUGH THE
AREA...FIRST AT KFAY AND KRWI. STRATUS WILL LIKELY HAND AROUND
LONGER AT KGSO/KINT...POSSIBLY UNTIL AROUND 16Z. WITH AT LEAST
PARTIAL CLEARING...HEATING AND DESTABILIZATION WILL SUPPORT SCATTERED
SHOWERS AND STORMS DURING THE AFTERNOON. CONFIDENCE IN TIMING OF
IMPACT AT TERMINALS IS TOO LOW FOR MENTION OF THUNDER IN TAFS...BUT
PROBABILITIES ARE GREATER AT KRDU/KFAY/KRWI. EXPECT AT LEAST MFR
CEILINGS IN THE TRIAD...IF NOT EVENTUALLY VFR EVERYWHERE DURING THE
AFTERNOON.
A COLD FRONT WILL APPROACH FROM THE WEST DURING THE
EVENING...NEARING KGSO AND KINT BY THE END OF THE CURRENT TAF
PERIOD. ADDITIONAL SHOWERS/STORMS MAY BE POSSIBLE WITH THE FRONT
AFTER 06Z.
OUTLOOK...ONCE THE COLD FRONT CLEARS THE AREA WEDNESDAY
MORNING...VFR CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...BLS
SHORT TERM...DJF
LONG TERM...WSS
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
337 AM EDT TUE AUG 12 2014
.SYNOPSIS...
LOW PRESSURE WILL MOVE NORTHEAST THROUGH THE CENTRAL GREAT LAKES
TODAY AND FORCE A COLD FRONT EAST ACROSS THE REGION. A TROUGH OF LOW
PRESSURE WILL EXTEND BACK SOUTHWEST FROM THE LOW PRESSURE ACROSS THE
LOCAL AREA BY WEDNESDAY EVENING. HIGH PRESSURE WILL MOVE EAST AND BE
OVER OHIO BY FRIDAY MORNING AND TO THE MID ATLANTIC COAST BY
SATURDAY MORNING.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER LEVEL TROUGH WILL CONTINUE TO DIG SOUTH INTO THE FORECAST AREA
TODAY. THE SURFACE LOW PRESSURE WILL MOVE NORTH SLIGHTLY ALLOWING A
COLD FRONT TO SLIDE EAST ACROSS THE FORECAST AREA. DEEP MOISTURE WE
EXPERIENCED OVER THE LAST 24 HOURS HAS SINCE MOVED EAST OF THE
REGION. AS COLD FRONT MOVES EAST INTO THE AREA...SOME SHOWER AND
THUNDERSTORM ACTIVITY WILL LIKELY DEVELOP WITH THE FRONT. STILL
EXPECTING SOME SUN AHEAD OF THE FRONTAL BOUNDARY AND THIS WILL HELP
DESTABILIZE THE ATMOSPHERE...ESPECIALLY IN THE EAST. SPC HAS A
SLIGHT RISK FOR SEVERE THUNDERSTORMS IN THE EAST AT THIS TIME.
TEMPERATURES WILL ONCE AGAIN BE TRICKY DO TO TIMING OF THE COLD
FRONT. RIGHT NOW...MODELS ARE IN FAIRLY GOOD AGREEMENT WITH COLD
FRONT PUSHING INTO TOLEDO AND FINDLAY AROUND NOON AND THEN THROUGH
ERIE BY 8 PM THIS EVENING. THE MORE SUN WE GET THE HIGHER THE
TEMPERATURES. AS MENTIONED...BATTLING THE TIMING OF THE FRONT AS
WELL. BUMPED UP MAX TEMPERATURES A FEW DEGREES FOR TODAY TO ACCOUNT
FOR THE SUN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
UPPER LEVEL TROUGH STALLS OVER THE NORTHEASTERN UNITED STATES WHILE
IT EVENTUALLY MORPHS INTO A LARGE UPPER LEVEL LOW PRESSURE SYSTEM BY
THURSDAY NIGHT. THIS IS IN RESPONSE TO A PIECE OF ENERGY PLOWING
INTO THE WESTERN UNITED STATES. AN UPPER LEVEL RIDGE OVER THE WEST
CENTRAL UNITED STATES WILL DEAMPLIFY WITH TIME AND WASH OUT BY
FRIDAY NIGHT.
SURFACE LOW PRESSURE WILL CONTINUE TO PULL OUT TO THE NORTHEAST WITH
TIME AND DRAG THE COLD FRONT EAST AND WELL OUT OF THE REGION TONIGHT
AND WEDNESDAY. A TROUGH OF LOW PRESSURE WILL SETTLE IN OVER THE
REGION WEDNESDAY NIGHT AND THEN LIFT OUT AS WELL.
LARGE AREA OF HIGH PRESSURE IS PROGGED TO BUILD EAST SOUTHEAST INTO
THE FORECAST AREA AND BRING A RETURN BACK TO FAIR WEATHER INTO THE
WEEKEND. THE HIGH EVENTUALLY SHIFTS TO THE MID ATLANTIC COAST
BRINGING A RETURN SOUTHERLY FLOW BACK TO THE REGION.
COLD AIR ADVECTION IN THE WAKE OF THE COLD FRONT WILL TAKE PLACE AND
THEN WE SHOULD SEE A GRADUAL WARM UP BY THE LATTER PORTION OF THE
FORECAST PERIOD.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
THE FORECAST IS BEGINNING TO CHANGE WITH BOTH THE GFS AND ECMWF
BRINGING IN A LOW AND FRONT FOR THE WEEKEND. INTRODUCED 20 POPS FOR
SATURDAY NIGHT AND 30 POPS ON SUNDAY AND THEN ANOTHER WEATHER SYSTEM
WILL BE MOVING IN FOR EARLY NEXT WEEK. TEMPERATURES WILL GO BACK
ABOVE NORMAL EARLY NEXT WEEK.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
A BATCH OF SHOWERS AND THUNDERSTORMS WILL BE EAST OF THE FORECAST
AREA BY 4 AM. SKIES ARE CLEARING FROM THE WEST. WITH PLENTY OF
RAIN EXPECTING FOG AND STRATUS TO DEVELOP. A COLD FRONT WILL BE
MOVING THROUGH DURING THE AFTERNOON. GOING WITH THE HRRR FOR THE
DEVELOPMENT OF THE SQUALL LINE WITH THE FRONT AND SOME SHOWERS
BEHIND IT WITH A TROF. CONDITIONS WILL BEGIN TO IMPROVE FROM THE
WEST AFTER DARK.
OUTLOOK...NON VFR CEILINGS AND VISIBILITY IN PRECIPITATION LINGERING
LATE TUESDAY NIGHT/WEDNESDAY ACROSS NE OH/NW PA.
&&
.MARINE...
CONTINUING THE SMALL CRAFT ADVISORY ON THE EAST END OF THE LAKE
THROUGH 10 AM BECAUSE OF 15 TO 25 KNOT WINDS FROM THE SOUTH. A COLD
FRONT WILL BE CROSSING THE LAKE TODAY. SOME OF THE THUNDERSTORMS MAY
PROMPT THE NEED FOR A SPECIAL MARINE WARNING...ESPECIALLY LATER
TODAY AND ESPECIALLY ON THE EAST END. THE WINDS WILL SLOWLY PICK UP
TONIGHT THROUGH THURSDAY IN THE COLD ADVECTION. A SMALL CRAFT
ADVISORY MAY BE NEEDED. THIS IS NOT A REAL COLD OUTBREAK AND THE
AIRMASS DRIES OUT QUICKLY. BECAUSE OF THAT WILL NOT MENTION
WATERSPOUTS ON WEDNESDAY...BUT THIS WILL HAVE TO BE WATCHED.
HIGH PRESSURE WILL BEGIN BUILDING IN ON THURSDAY AND WILL MOVE EAST
OF THE LAKE ON SATURDAY AS ANOTHER WEATHER SYSTEM APPROACHES. NOT
EXCEPTING CONDITIONS TO MEET SMALL CRAFT ADVISORY CRITERIA FRIDAY
THROUGH SATURDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR LEZ148-
149.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
153 AM EDT TUE AUG 12 2014
.SYNOPSIS...
LOW PRESSURE ACROSS NORTHWEST OHIO WILL DRIFT NORTHWARD REACHING
LAKE HURON BY TUESDAY MORNING...AND IT WILL TAKE A COLD FRONT
ACROSS THE AREA DURING THE DAY TUESDAY. A TROUGH WILL HANG BACK
ACROSS THE EASTERN LAKES INTO WEDNESDAY WHILE HIGH PRESSURE ACROSS
THE UPPER MIDWEST AND THE GREAT LAKES SHIFTS EASTWARD TO END THE
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LINE OF SHOWERS AND THUNDERSTORMS WILL CONTINUE TO MOVE EAST
ACROSS THE CENTRAL PORTIONS OF THE FORECAST AREA INTO THE EAST.
THIS IS THE BACK EDGE OF THE PRECIPITATION UNTIL THE COLD FRONT
MOVES EAST ACROSS THE FORECAST AREA LATER TODAY. SO MADE SOME
ADJUSTMENTS TO GRIDS AND FORECAST TO ACCOUNT FOR THE CHANGES AND
TIMING.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
EASTERN HALF OF THE AREA WITHIN SPC SLIGHT RISK FOR SEVERE
THUNDERSTORMS FOR TUESDAY. AS UPPER TROUGH AMPLIFIES/MID LEVEL
FLOW INCREASES...INSTABILITY/CONVECTION FUELED BY JUST ENOUGH
DAYTIME HEATING COULD BE ENOUGH TO ALLOW SOME OF THE STORMS TO GET
ON THE STRONG SIDE. COLD FRONT CROSSES THE AREA BY EVENING. A FEW
SHOWERS MAY FOLLOW TUESDAY EVENING/NIGHT AS THE UPPER TROUGH AXIS
HAS YET TO CROSS. IT WILL BE FAIRLY CLOUDY TUESDAY...AND HIGHS
WILL TOP OUT IN THE UPPER 70S.
SO LARGE TROUGH ENCOMPASSES THE GREAT LAKES TO NEW ENGLAND AND
AREA WILL REMAIN BELOW NORMAL. A FEW SHOWERS MAY REMAIN ON
WEDNESDAY AS ANOTHER MINOR PIECE OF ENERGY MOVES THROUGH THE
TROUGH. BY THURSDAY THOUGH...MORE DRYING AND HIGH PRESSURE MOVES
ACROSS THE AREA. TEMPERATURES WILL STILL BE HELD TO THE 70S FOR
HIGHS AND 50S AND NIGHT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGH PRESSURE WILL BUILD OVER THE REGION DURING THE PERIOD. THE
LONG RANGE GUIDANCE IS SIMILAR SO CONFIDENCE IS FAIRLY HIGH TODAY.
THE SURFACE RIDGE WILL MOVE EAST OF THE LOCAL ARE BY NEXT MONDAY.
THIS WILL ALLOW TEMPS AND SURFACE DEW POINTS TO SLOWLY BUILD DURING
THE PERIOD. AFTER STARTING OUT BELOW NORMAL FRIDAY...MONDAY WILL BE
RATHER WARM AND MUGGY. WILL GO MID 80S FOR HIGHS FOR MONDAY BUT
SUSPECT THAT WE WILL EVENTUALLY NEED TO GO WARMER.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
A BATCH OF SHOWERS AND THUNDERSTORMS WILL BE EAST OF THE FORECAST
AREA BY 4 AM. SKIES ARE CLEARING FROM THE WEST. WITH PLENTY OF
RAIN EXPECTING FOG AND STRATUS TO DEVELOP. A COLD FRONT WILL BE
MOVING THROUGH DURING THE AFTERNOON. GOING WITH THE HRRR FOR THE
DEVELOPMENT OF THE SQUALL LINE WITH THE FRONT AND SOME SHOWERS
BEHIND IT WITH A TROF. CONDITIONS WILL BEGIN TO IMPROVE FROM THE
WEST AFTER DARK.
OUTLOOK...NON VFR CEILINGS AND VISIBILITY IN PRECIPITATION LINGERING
LATE TUESDAY NIGHT/WEDNESDAY ACROSS NE OH/NW PA.
&&
.MARINE...
LOW PRESSURE WILL PASS WELL TO THE NORTH OF LAKE ERIE ON TUESDAY. A
WARM FRONT FROM THE LOW WILL LIFT NORTH OF THE LAKE TONIGHT CAUSING
THE EASTERLY FLOW TO BECOME SOUTH TO SOUTHWEST. A COLD FRONT WILL
CROSS THE LAKE ON TUESDAY. WINDS WILL BECOME WEST AS THIS OCCURS
BUT SPEEDS SHOULD NOT GET STRONG ENOUGH FOR SMALL CRAFT CONDITIONS.
LOT`S OF THUNDER IS EXPECTED THE NEXT 24 HOURS OR SO. PRECIP WILL
LINGER IN THE EAST INTO WEDNESDAY WITH HIGH PRESSURE THEN BUILDING
IN FROM THE WEST THE REMAINDER OF THE PERIOD. WEST TO SOUTHWEST
WINDS UNDER 15 KNOTS ARE EXPECTED FROM WEDNESDAY THROUGH SUNDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR LEZ148-
149.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...LOMBARDY
SHORT TERM...OUDEMAN
LONG TERM...KUBINA
AVIATION...KIELTYKA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
416 AM EDT TUE AUG 12 2014
.SYNOPSIS...
A STRONG FRONTAL SYSTEM WILL CROSS THE AREA TODAY AND TONIGHT.
GENERALLY DRIER AND COOLER CONDITIONS CAN BE EXPECTED FOR THE
SECOND HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN ACTIVE DAY IS IN STORE AS A STRONG UPPER TROUGH AND
ACCOMPANYING FRONTAL SYSTEM ENTERS THE REGION. BIGGEST ISSUES
TODAY WILL BE THE POTENTIAL FOR LOCALLY HEAVY RAINS AND
POSSIBILITY OF SEVERE THUNDERSTORMS.
ONCE AGAIN THIS SUMMER WE ARE DEALING WITH A WEATHER SYSTEM
BRINGING UNSEASONABLY STRONG DYNAMICS TO THE FORECAST AREA.
ENSEMBLES AND OPERATIONAL GUIDANCE ALL SHOW A 40-55KT...4-6 STD
DEV...LOW LEVEL SOUTH-SOUTHEASTERLY JET SURGING INTO THE REGION.
THIS HELPS PUSH PWATS IN THE 1.5-2.0 INCH RANGE OVER THE ENTIRE
FCST AREA DURING THE DAY.
THE SETUP SEEMS IS PRIMED FOR A WIDESPREAD MODERATE TO HEAVY RAIN
OVER THE NEXT 12-18 HOURS. HAVE DISCUSSED A POSSIBLE FLOOD WATCH
WITH NEIGHBORING OFFICES AND CONSENSUS IS TO LEAN AWAY FOR THE
TIME BEING GIVEN THE EXPECTED QPF AVERAGING 1-2" AND RECENT
PERIOD OF DRY WEATHER. THE BEST CHANCE FOR DEVELOPING FLOODING
ISSUES SEEMS TO BE ALONG SOME OF THE SMALLER CREEKS AND STREAMS
AND WILL BE HANDLED WITH SHORT TERM ADVISORY/FLOOD PRODUCTS. THE
BEST CHANCE OF THIS WOULD SEEM TO BE OVER ABOUT THE EASTERN HALF
OF MY FCST AREA.
ANOTHER CONCERN IS THAT WHEN THE OCCLUSION/WARM FRONT ENTERS THE
AREA...MARGINAL INSTABILITY AND STRONG SHEAR COULD RESULT IN
SOME LOCALLY SEVERE THUNDERSTORMS WITH AN ISOLATED TORNADO NOT OUT
OF THE QUESTION. RAP AND GFS SHOW A BULLSEYE OF STRONG LOW LEVEL
HELICITY OVER SOUTH CENTRAL PA...IN THE VICINITY OF THE WARM
FRONT THAT WILL BE SLOWLY MOVING NORTH THROUGH EARLY AFTERNOON.
HEATING WILL BE HARD TO COME BY GIVEN THE EXPECTED CLOUD
COVER...BUT IF THE DRY SLOT CAN MANAGE TO INTRODUCE SOME BREAKS IN
THE CLOUDS...MODEL PROJECTIONS OF CAPES IN THE 1000-1500J RANGE
COULD BE REALIZED...HELPING DEVELOP SOME STRONGER UPDRAFTS
INCREASING THE POTENTIAL FOR SEVERE WEATHER. AN EXPECTED LOW LCL
IN THE VERY MOIST ENVIRONMENT WOULD NOT BE A HINDERING FACTOR TO
TORNADO FORMATION SHOULD WE MANAGE TO DEVELOP SOME SUPERCELLS.
SHORT RANGE OPERATIONAL MODELS AGREE IN FORMING A WAVE OR WAVES
ALONG THE FRONT AS IT ENTERS THE MID ATLANTIC STATES...KEEPING
THE RAINFALL GOING OVER EASTERN PA INTO THE EVENING
HOURS. THE RAIN SHOULD TAPER OFF TO SCATTERED SHOWERS OVER MY
EASTERN ZONES AFTER MIDNIGHT.
HIGHS GENERALLY IN THE 70S TODAY WILL BE SOME 5-10 DEG BELOW
NORMAL...WHILE THE OVERNIGHT LOWS WILL BE RELATIVELY MILD FOR
MID AUGUST IN THE MID 50S TO MID 60S.
&&
.SHORT TERM /WEDNESDAY/...
THE SURFACE LOW AND FRONTAL SYSTEM WILL BE MOVING AWAY FROM THE
REGION WEDNESDAY...BUT WITH THE LAGGING UPPER TROUGH AND COLD AIR
ALOFT WE WILL SEE AT LEAST SOME SCATTERED SHOWERS...AND EVEN THE
POSSIBILITY OF A RUMBLE OF THUNDER. MID LEVEL LAPSE RATES ARE NOT
PROGGED TO BE PARTICULARLY IMPRESSIVE SO THE THUNDER CHANCES WILL
NOT BE ESPECIALLY HIGH.
IT WILL BE ANOTHER COOLER THAN NORMAL DAY RANGING FROM THE UPPER
60S TO UPPER 70S NW-SE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MUCH OF THE EXTENDED PERIOD WILL BE DOMINATED BY COOL CYCLONIC
FLOW ALOFT AROUND THE UNSEASONABLY STRONG UPPER LOW/TROUGH THAT
WILL ONLY SLOWLY LIFT THROUGH THE NERN US. THIS SHOULD MEAN A
FAIR AMOUNT OF STRATOCU COOKING UP WITH DAYTIME HEATING AND
PERHAPS A FEW SHOWERS STICKING AROUND INTO THURSDAY.
ENSEMBLES AND THE GFS/ECMWF ALL SHOW UPPER HEIGHTS BEGINNING TO
REBOUND BY THE END OF THE WEEK WITH DRY CONDITIONS FOR FRIDAY AND
SATURDAY. THE DIFFERENCES BEGIN TO ARISE AFTER SATURDAY WITH THE
ECMWF SHOWING A SHARP SHORTWAVE DROPPING DOWN INTO PA FROM NORTH
OF THE LAKES WHILE THE GFS/GEFS INTRODUCE WET WEATHER UNDER A
FLATTER UPPER FLOW IMPLYING WE BECOME VULNERABLE TO CONVECTION
FORMING OVER THE UPPER MIDWEST THAT GETS FUNNELED EAST UNDER THE
MUCH FLATTER UPPER FLOW. GIVEN THE UNCERTAINTY I OPTED FOR A
PRETTY BLAND SMALL MENTION OF SHOWERS THROUGH MONDAY.
FOR THE VERY EXTENDED THE ECMWF SHOWS A RARE...FOR THIS
SUMMER...SURGE IN THE WESTERN ATLANTIC SUBTROPICAL RIDGE WITH 500
MB HEIGHTS EXCEEDING 5900M ALL THE WAY INTO SOUTHERN NEW ENGLAND.
GIVEN THE TENDENCY FOR A TROUGH TO DOMINATE OUR WEATHER MUCH OF
THIS SUMMER...THIS SOLUTION HAS TO BE VIEWED DUBIOUSLY AT THIS
TIME...BUT MAY GIVE HOPE TO REAL SUMMER LOVERS THAT WE COULD HAVE
AT LEAST ONE TRUE HEAT WAVE IN STORE FOR US.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
A SLOW-MOVING WARM FRONT WILL APPROACH PENNSYLVANIA FROM THE OHIO
VALLEY OVERNIGHT...SPREADING LOWERING CIGS AND SHRA INTO THE
REGION. THE REGION OF MOST CONCERN WILL BE THE CENTRAL
MTNS...INCLUDING KJST/KAOO/KUNV/KBFD...WHERE SE FLOW ASCENDING THE
HIGHER TERRAIN HAS RESULTED IN IFR CIGS. CIGS HAVE FALLEN TO
800FT OR LOWER AT KJST...BFD AND KAOO. UNV REMAINS OVERCAST AT
1500FT. MODELS STILL SUGGEST UNV COULD DROP TO IFR...BETWEEN 09Z
TO 15Z. IPT IS RECEIVING HEAVIER RAIN...YET IFR FOR THEM SEEMS
LESS LIKELY THOUGH POSSIBLE. MDL SOUNDINGS SUGGEST THE LOWER
ELEVATION AIRFIELDS OF KMDT AND KLNS WILL LIKELY GO NO LOWER THAN
MVFR LATE TONIGHT.
A BAND OF STRONG SOUTHERLY WINDS ALOFT WILL MOVE THROUGH THE
REGION LATE TONIGHT THROUGH TUESDAY...ACCOMPANIED BY NUMEROUS
SHRA AND TSRA. WARM FRONT IS EXPECTED TO LIFT INTO THE AREA BY TUE
AFTN...CAUSING CIGS TO RISE A BIT. HOWEVER...TROUGH OF LOW PRES
APPROACHING FROM THE WEST WILL PRODUCE NUMEROUS SHRA/TSRA...WHICH
COULD PRODUCE BRIEF IFR VSBYS AND GUSTY WINDS DURING THE PM HOURS.
AN EXAMINATION OF LATEST MDL SOUNDINGS SUGGESTS WE WILL FALL JUST
SHORT OF LLWS CRITERIA LATE TONIGHT AND EARLY TUE...AS BAND OF
STRONG WINDS ALOFT PASSES OVR PA. HOWEVER...LOCALLY GUSTY SFC
WINDS ARE EXPECTED LATER TONIGHT AND EARLY TUESDAY. BUFKIT
SOUNDINGS SUPPORT OCNL GUSTS BTWN 20-25KTS OVR THE CENTRAL
MTNS AND PERHAPS UP TO 30KTS TUE AM AT KIPT...WHERE TOPOGRAPHY
EFFECTS ENHANCE THE GUST POTENTIAL. ACROSS SE PA...THE WINDS ARE
LIKELY TO BE LIGHTER AT KMDT AND KLNS.
OUTLOOK...
TUE NIGHT...SHRA/TSRA. LOW CIGS/VSBYS POSSIBLE.
WED...AM SHRA/LOW CIGS POSSIBLE.
THU-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
134 AM EDT TUE AUG 12 2014
.SYNOPSIS/...
A STRONG FRONTAL SYSTEM WILL CROSS THE AREA TODAY AND TONIGHT.
GENERALLY DRIER AND COOLER CONDITIONS CAN BE EXPECTED FOR THE
SECOND HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
RADAR SHOWS A LARGE AREA OF SHOWERS WITH EVEN SOME EMBEDDED
THUNDERSTORMS EVIDENT OVER WESTERN PARTS OF THE AREA. REGIONAL
RADAR SHOWS CONVECTION FIRING UPSTREAM ALL THE WAY BACK TO
SOUTHERN OHIO AND WEST VIRGINIA...SUPPORTING THE SHORT RANGE HIGH
RES MODEL IDEAS OF FREQUENTS SHOWERS AND THUNDERSTORMS RIGHT
THROUGH THE MORNING INTO THE AFTERNOON.
A BLEND OF HPC AND MODEL ENSEMBLE QPF SUPPORTS A WIDESPREAD
SOAKING RAIN OF 1 TO 2 INCHES...WITH SOME LOCALIZED HIGHER AMOUNTS
LIKELY OVER EASTERN AREAS.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/...
THE SFC BASED STABILITY LOOKS TO REMAIN HIGH THROUGHOUT MOST OF
THE UPCOMING EVENT. SOUNDINGS DO LOOK MOIST ADIABATIC SO THUNDER
WILL PROBABLY BE ISOLATED TO POCKETS WHERE BEST FORCING APPEAR.
THE DEEPEST MOISTURE AND AXIS OF STRONGEST WINDS WILL BE BISECT
THE STATE TUESDAY...SO A VERY WET TUESDAY IS IN STORE FOR THE
CENTRAL AREAS IN THE MORNING AND EASTERN LOCATIONS ALL DAY
LONG...AND THROUGH THE NIGHT. SOME LLVL INSTABILITY COULD ENHANCE
THE RAIN RATES IN THE SE HALF OF THE AREA. GIVEN EXTENSIVE CLOUD
COVER AND PRECIPITATION...MOST AREAS WILL REMAIN IN THE U60S AND
L/M70S TUESDAY AFTERNOON.
SPC HAS PLACED MUCH OF THE AREA INTO THE SLIGHT RISK AREA FOR
TUESDAY...BUT WE WILL HAVE TO POKE SOME BIG HOLES IN THE CLOUDS
WHICH LOOK LIKE A FORMIDABLE TASK. THE EXCEPTION TO THIS MAY BE
OVER THE W/SW WHERE DRY AIR MAY SHOVE IN FROM THE WEST IN THE
AFTN. HAVE ONLY MENTIONED SLIGHT CHC THUNDER FOR NOW. THE
SOUNDINGS/CROSS SECTIONS LOOK VERY MOIST THRU MOST OF THE AREA.
UNSETTLED AND WET WEATHER WILL CONTINUE INTO TUESDAY NIGHT AS THE
FRONT PASSES THROUGH MOST OF THE AREA...BEFORE THE UPPER LOW
PUSHES ACROSS NY STATE ON WED/THU. THE FRONT WILL LIKELY HANG UP
AS THE WAVE DEVELOPING ALONG THE COAST MOVES UP TO OUR LATITUDE.
POTENTIAL HEAVIER RAINS WILL BE OVER EASTERN SECTIONS OF CWA
TUESDAY NIGHT.
WITHOUT AN SPECIFIC INTENSE PERIOD OF RAIN/CONVECTION...AND LITTLE
OR NO RAIN IN THE LAST 6-7 DAYS...NO FLOOD WATCH AT THIS POINT.
BUT WILL LEAVE MENTIONS OF HEAVY RAIN POTENTIAL IN THE HWO.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
SOME MODEL SPREAD...CLOUDS COULD REMAIN STUBBORN ACROSS THE MTNS
ON WED...AS COLD POOL ASSOCIATED WITH UPPER LOW REMAINS OVERHEAD.
THE WAVE ALONG THE EAST COAST APPEARS TO SLOW THINGS UP. THUS SOME
SHOWERS AND STORMS STILL LIKELY...AT LEAST EARLY ON. DID NOT MAKE
A LOT OF CHANGES TO THE POPS. STILL A LOT OF MODEL SPREAD ON THE
DETAILS. THIS BEEN THE PATTERN FOR MUCH OF THE SUMMER SO FAR.
STILL A CHC OF A SHOWER ON THU ACROSS THE NORTH WITH THE UPPER
LVL LOW.
AFTER THIS...WENT WITH A DRY FOR FCST INTO NEXT MONDAY. A RATHER
DEEP UPPER LVL LOW WILL SLOWLY LIFT OUT...LEAVING US IN A NW
FLOW OF COOLER AND DRIER AIR.
TEMPS REMAIN BELOW AVERAGE LATE WEEK...WITH A MODERATING TREND
FOR THE WEEKEND AS RIDGE AXIS SLIDES THROUGH OHIO VALLEY. THIS
WILL COINCIDE WITH AN EXTENDED PERIOD OF DRY WEATHER.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
A SLOW-MOVING WARM FRONT WILL APPROACH PENNSYLVANIA FROM THE OHIO
VALLEY TONIGHT...SPREADING LOWERING CIGS AND SHRA INTO THE REGION.
THE REGION OF MOST CONCERN WILL BE THE CENTRAL MTNS...INCLUDING
KJST/KAOO/KUNV/KBFD...WHERE SE FLOW ASCENDING THE HIGHER TERRAIN
IS LIKELY TO RESULT IN IFR CIGS. CIGS HAVE FALLEN TO 900FT AT KJST
AND KAOO AT 03Z AND RAP SOUNDINGS SUGGEST KUNV AND KBFD WILL
FOLLOW SUIT BY ARND 06Z. MDL SOUNDINGS SUGGEST THE LOWER ELEVATION
AIRFIELDS OF KMDT AND KLNS WILL LIKELY GO NO LOWER THAN MVFR LATE
TONIGHT.
A BAND OF STRONG SOUTHERLY WINDS ALOFT WILL MOVE THROUGH THE
REGION LATE TONIGHT AND TUESDAY...ACCOMPANIED BY NUMEROUS SHRA
AND TSRA. WARM FRONT IS EXPECTED TO LIFT INTO THE AREA BY TUE
AFTN...CAUSING CIGS TO RISE A BIT. HOWEVER...TROUGH OF LOW PRES
APPROACHING FROM THE WEST WILL PRODUCE NUMEROUS SHRA/TSRA...WHICH
COULD PRODUCE BRIEF IFR VSBYS AND GUSTY WINDS DURING THE PM HOURS.
AN EXAMINATION OF LATEST MDL SOUNDINGS SUGGESTS WE WILL FALL JUST
SHORT OF LLWS CRITERIA LATE TONIGHT AND EARLY TUE...AS BAND OF
STRONG WINDS ALOFT PASSES OVR PA. HOWEVER...LOCALLY GUSTY SFC
WINDS ARE EXPECTED LATER TONIGHT AND EARLY TUESDAY. BUFKIT
SOUNDINGS SUPPORT OCNL GUSTS BTWN 20-25KTS OVR THE CENTRAL
MTNS AND PERHAPS UP TO 30KTS TUE AM AT KIPT...WHERE TOPOGRAPHY
EFFECTS ENHANCE THE GUST POTENTIAL. ACROSS SE PA...THE WINDS ARE
LIKELY TO BE LIGHTER AT KMDT AND KLNS.
OUTLOOK...
TUE NIGHT...SHRA/TSRA. LOW CIGS/VSBYS POSSIBLE.
WED...AM SHRA/LOW CIGS POSSIBLE.
THU-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
440 AM EDT TUE AUG 12 2014
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL ENHANCE CHANCES FOR SHOWERS AND
THUNDERSTORMS BEFORE IT PASSES THROUGH THE AREA TONIGHT. DRY HIGH
PRESSURE WILL THEN SETTLE OVER THE REGION AND REMAIN THROUGH THE
END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
430 AM UPDATE...WITH MOST OF THE PRECIP ACTIVITY ACRS THE CWFA
WANING AS INSTABILITY IS EXHAUSTED...ADJUSTED POPS GENERALLY
DOWNWARD THRU THE EARLY MRNG. NEWEST AVBL HRRR SUGGESTS NO
MEASURABLE PRECIP DEVELOPMENT UNTIL AFTER DIURNAL HEATING BEGINS AND
THIS SEEMS REASONABLE.
AS OF 300 AM EDT...HEIGHTS FALL STEADILY TODAY AND TONIGHT AS UPPER
TROUGH DIGS INTO THE MID-ATLANTIC AND CAROLINAS. A SFC LOW WILL LIFT
NWD ACROSS LAKE HURON AND THE TRAILING COLD FRONT WILL SLOWLY
PROGRESS ACRS THE SRN APPALACHIAN REGION LATE AFTERNOON AND
OVERNIGHT. THE WEDGE WHICH REMAINED OVER MUCH OF THE AREA SUN-MON
APPEARS TO HAVE ALREADY RETREATED INTO CENTRAL NC/VA WITH SOUTHERLY
FLOW PREVAILING INTO THE FA. LLVL WINDS WILL CONTINUE TO VEER
GRADUALLY TO SW THIS MORNING. THE WEDGE WILL RETREAT FURTHER AND
THERMAL GRADIENT WILL WEAKEN ACRS THE AREA TODAY...AND DIURNALLY
DRIVEN CONVECTION WILL BE THE PRIMARY DRIVER FOR PRECIP. NAM/GFS
INDICATE THE DEVELOPMENT OF A PREFRONTAL TROUGH OVER THE SE HALF OF
THE FA THIS AFTN WHICH IS EXPECTED TO PROVIDE A FOCUSING MECHANISM.
MODEL GUIDANCE SUGGESTS IT WILL BE STRONGER THAN THE UPSLOPE FORCING
PROVIDED BY THE VEERED FLOW...SO GREATEST POPS ARE FCST EAST OF THE
BLUE RIDGE. MOSTLY CLOUDY SKIES AND STILL RELATIVELY LOW THICKNESSES
WILL KEEP HIGHS A CATEGORY OR SO BELOW CLIMO OVER MOST OF THE AREA.
SBCAPE VALUES PROGGED BY NAM/GFS ARE STRONGER THAN WHAT WE/VE DEALT
WITH THE PAST FEW DAYS...1000-1500 J/KG. THIS VALUE SUPPORTED BY SREF
PROBS.H5 FLOW INCREASES STEADILY THRU THE DAY AS THE BASE OF THE
TROUGH APPROACHES...WITH UPPER DRYING ALSO OCCURRING THEREIN. 0-6KM
SHEAR WITH UNIDIRECTIONAL PROFILE IS 25-30 KT OVER THE AREA BY SUNSET
WHICH IS SUFFICIENT TO EXPECT AT LEAST LOOSE LINEAR ORGANIZATION TO
CONVECTIVE ACTIVITY. THE DRYING ALOFT SUGGESTS HIGHER DCAPES AND A
MARGINAL STRONG/SEVERE WIND THREAT. SPC HAS MOST OF OUR AREA WITHIN
THE 5 PERCENT CONTOURS FOR WIND/HAIL ON THE NEW DAY 1 OTLK. THE WIND
THREAT SEEMS LIKE A BETTER BET BUT FREEZING LEVELS ARE NOT ESPECIALLY
HIGH SO AT LEAST NEAR-SEVERE HAIL IS A POSSIBILITY. PWATS REMAIN
ELEVATED BUT WILL DROP AS THE DRIER AIR WORKS IN ALOFT...STILL
SUPPORTING WIND AS THE PRIMARY CONCERN.
THE SFC FRONT PUSHES INTO THE MTNS THIS EVENING AND IS TIMED TO EXIT
THE CWFA BEFORE DAYBREAK. DOWNSLOPING NW FLOW EAST OF THE MTNS SHOULD
LEAD TO CLEARING SKIES THERE AFTER MIDNIGHT...BUT SUFFICIENT LLVL
MOISTURE IS PRESENT TO KEEP LINGERING CLOUDS/POPS ALONG THE TENN
BORDER LATER INTO THE NIGHT. MIN TEMPS WILL BE SLIGHTLY BELOW CLIMO
IN THE DRIER CONTINENTAL AIRMASS AND WITH PARTIAL CLEARING.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 250 AM TUESDAY...VERY QUIET AND UNSEASONABLY PLEASANT WEATHER
IS EXPECTED DURING THE SHORT TERM...BY WHICH TIME A CONTINENTAL AIR
MASS WILL BE WELL-ESTABLISHED ACROSS THE SOUTHEAST AND MID-ATLANTIC
BENEATH AN UPPER LONG WAVE TROUGH. WHILE DAYTIME TEMPERATURES WILL
BE AS MUCH AS 5 DEGREES BELOW CLIMO...THE MOST NOTICEABLE DIFFERENCE
FROM TYPICAL AUGUST WEATHER WILL BE THE LOW DEWPOINTS...WHICH WILL
LIKELY MIX OUT INTO THE 50S IN MOST AREAS WED AND THU AFTERNOONS.
THE DRY AIR WILL ALSO SUSTAIN MIN TEMPS AT LEAST 5 DEGREES BELOW
NORMAL. NEEDLESS TO SAY...PRECIP CHANCES ARE VIRTUALLY NIL THROUGH
THE PERIOD.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 3 AM TUESDAY...THERE IS ACTUALLY A RATHER SIGNIFICANT CHANGE
IN THE GLOBAL MODELS RE: THE SYNOPTIC PATTERN OVER THE CONUS FOR THE
WEEKEND AND EARLY NEXT WEEK. WHEREAS YESTERDAY/S RUNS WERE
ATTEMPTING TO NOSE THE SUBTROPICAL RIDGE INTO THE SOUTHEAST BY
SATURDAY OR SO...BOTH THE GFS AND THE ECMWF HAVE PICKED UP ON A
SHORT WAVE TROUGH IN THE FOUR CORNERS REGION ROUNDING THE STRONG
WESTERN HIGH AND ESSENTIALLY BREAKING DOWN THE RIDGE. THIS WOULD
TEND TO MAINTAIN ANOMALOUSLY LOW HEIGHTS ACROSS THE EASTERN CONUS
THROUGH THE PERIOD. IN FACT...THE AFOREMENTIONED SHORT WAVE COULD
MANAGE TO REINFORCE THE TROUGH TO SOME EXTENT BY EARLY NEXT
WEEK...BUT EXACTLY HOW THAT WILL EVOLVE IS VERY UNCERTAIN ATTM.
IN THE INTERIM...A SHORT WAVE ROUNDING THE BASE OF THE UPPER LOW
ACROSS SOUTHEAST CANADA IS EXPECTED TO SEND A REINFORCING COOL FRONT
TOWARD THE AREA LATE THIS WEEK. HOWEVER...IT APPEARS THE ATMOSPHERE
MAY BE TOO DRY/STABLE TO SUPPORT MUCH IN THE WAY OF CONVECTION. SOME
TOKEN SLIGHT CHANCES WILL NEVERTHELESS BE CARRIED FRIDAY...MAINLY
ACROSS THE HIGH TERRAIN. DEPENDING UPON THE EVOLUTION OF THE /RIDGE
BUSTING/ SHORT WAVE...MOISTURE MAY BEGIN TO INCREASE BY THE END OF
THE PERIOD... AND CONVERGENCE TOWARD MORE CLIMO-APPROPRIATE POPS
SEEMS REASONABLE BY DAY 7. TEMPS ARE GENERALLY EXPECTED TO REMAIN
SLIGHTLY BELOW NORMAL THROUGH THE PERIOD.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
AT KCLT...IFR HAS CREPT BACK IN ON MOIST SELY FLOW. EVEN AS AN
APPROACHING TROUGH VEERS THE LLVL FLOW BETWEEN NOW AND DAWN...ENOUGH
UPGLIDE SHOULD STILL BE PRESENT TO MAINTAIN THE CIGS. THE LIGHT
WINDS ARE EXPECTED TO KEEP THINGS MIXED ENOUGH TO PRECLUDE ANY LIFR.
THOUGH SOME SPRINKLES OR VERY LIGHT SHOWERS COULD OCCUR THIS
MRNG...SCT DIURNAL SHRA/TSRA THIS AFTN WILL PROVIDE THE BEST CHANCE
OF PRECIP IN THE PERIOD. COLD FRONT WILL APPROACH THIS EVENING...BUT
WINDS STAY SWLY THRU 06Z.
ELSEWHERE...LLVL FLOW HAS ALREADY VEERED TO SOUTHERLY ACRS THE AREA.
LINGERING ELEVATED INSTABILITY WILL DRIVE SOME SHRA AND A FEW TSRA
THRU THE EARLY MRNG...MAINLY ALONG AND JUST S/E OF THE BLUE RIDGE
WHERE UPSLOPE AND WARM UPGLIDE ARE WORKING TOGETHER. IFR WILL SLOWLY
EXPAND ACRS ALL THE SITES IF NOT ALREADY. THE CIGS SHOULD LIFT BY
MID-LATE MRNG IN TIME TO ALLOW SUFFICIENT TIME TO DESTABILIZE FOR
SCT TSRA. CHANCES ARE GENERALLY IN PROB30 RANGE. COLD FRONT WILL
SWEEP THROUGH TONIGHT...BUT THE WIND SHIFT IS NOT EXPECTED TO OCCUR
UNTIL AFTER 06Z EXCEPT AT KAVL.
OUTLOOK...DRIER VFR CONDITIONS WILL ARRIVE WED IN THE WAKE OF A COLD
FRONT AND CONTINUE THROUGH LATE WEEK.
CONFIDENCE TABLE...
08-14Z 14-20Z 20-02Z 02-08Z
KCLT HIGH 80% MED 70% LOW 57% HIGH 83%
KGSP HIGH 83% HIGH 88% HIGH 100% HIGH 100%
KAVL HIGH 81% MED 77% HIGH 100% HIGH 84%
KHKY HIGH 84% MED 73% HIGH 100% HIGH 80%
KGMU MED 75% HIGH 88% HIGH 100% HIGH 100%
KAND MED 77% HIGH 82% 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...WIMBERLEY
NEAR TERM...WIMBERLEY
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
350 AM CDT TUE AUG 12 2014
.SHORT TERM...
A FEW LINGERING SHOWERS SHOULD PUSH OUT OF THE FCST AREA BY FCST
VALID TIME AS MODEST UPPER LEVEL JET STREAKS EXITS TO THE EAST FROM
SRN OKLAHOMA. MODELS CONTINUE TO PROG DRIER LOW TO MID LEVEL AIR
ADVECTING INTO THE REGION...AND LOOKING AT WATER VAPOR IMAGERY AND
SFC OBS CANNOT REALLY DISPUTE THAT ATTM. LAST PLACE TO GET THE DRIER
AIR TODAY WILL BE THE SWRN CORNER OF THE FCST AREA WITH THE WRF-NAM
IN PARTICULAR. COULD SEE SOME ISOLATED SHOWERS DEVELOP THIS AFTN AS
THE AIR MASS THERE DESTABILIZES AS THE WRF-NAM AND HRRR SUGGEST.
CONFIDENCE IS LOW AND COVERAGE EXPECTED TO BE LIMITED ATTM SO WILL
KEEP POPS BELOW MENTION BUT WILL BE SOMETHING TO WATCH THROUGH THE
DAY. OTHERWISE TEMPS NOT TOO DIFFERENT THAN SEEN YESTERDAY AND IN
LINE OR JUST A DEGREE OR TWO BELOW MOS LOOKING FINE.
&&
.LONG TERM...
MODELS ARE IN GOOD AGREEMENT THROUGH THE END OF THE WEEK INTO THE
BEGINNING OF THE WEEKEND...PERSISTENT UPPER LEVEL RIDGE OVER THE
ROCKIES SLOWLY MIGRATES EASTWARD THROUGH THE WEEK RESULTING IN HIGH
PRESSURE ACROSS WEST TEXAS...BY SATURDAY A NUMBER OF UPPER LEVEL
DISTURBANCES BEGIN TO BREAK THE RIDGE DOWN DUE TO A NUMBER OF
SHORTWAVES EJECTING EASTWARD AND MONSOONAL FLOW OUT OF THE PACIFIC
WEST...GFS/ECMWF BEGIN TO DIVERGE SOMEWHAT ON SATURDAY AT
120HRS...GFS WORKS THE UPPER LEVEL INSTABILITY EASTWARD QUICKER THAN
THE ECMWF WHICH DEVELOPS A CLOSED LOW OVER THE CENTRAL PLAINS
RESULTING IN COLD FRONT EXTENDING FROM CENTRAL KANSAS THROUGH WEST
TEXAS SATURDAY NIGHT INTO SUNDAY WHICH WAS HINTED AT IN PREVIOUS
RUNS...THUS INCREASED POPS SLIGHTLY TOWARD THE END OF THE WEEKEND
MAINTAINING SIMILAR TREND OF PREVIOUS FORECAST...KEPT TEMPS IN NEAR
SEASONAL TO SLIGHTLY COOLER...IF WE STAY DRY TEMPS MAY APPROACH THE
100S OFF THE CAPROCK BY THE END OF THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 61 90 64 90 64 / 10 10 0 0 10
TULIA 62 91 65 92 66 / 0 0 0 0 10
PLAINVIEW 62 91 65 91 66 / 0 0 0 0 10
LEVELLAND 64 91 66 92 66 / 0 0 0 0 10
LUBBOCK 65 93 69 93 67 / 0 0 0 0 10
DENVER CITY 64 92 66 92 66 / 10 0 0 0 10
BROWNFIELD 65 92 67 93 66 / 0 0 0 0 10
CHILDRESS 67 95 70 97 71 / 0 0 0 0 10
SPUR 65 94 68 95 70 / 0 0 0 0 10
ASPERMONT 67 96 70 96 71 / 0 0 0 0 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07/55
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
605 AM MST TUE AUG 12 2014
.UPDATE...UPDATED AVIATION DISCUSSION.
&&
...POTENTIAL FOR FLASH FLOODING TODAY AND TONIGHT ACROSS MUCH OF THE
AREA...
.SYNOPSIS...
MOISTURE LEVELS WILL CONTINUE TO INCREASE TODAY AHEAD OF AN
APPROACHING LOW PRESSURE SYSTEM. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TODAY AND TONIGHT ACROSS MUCH OF THE AREA. SOME STORMS WILL
BE CAPABLE OF PRODUCING VERY HEAVY RAIN AND AREAS OF FLOODING. WITH
THE MOIST CONDITIONS...TEMPERATURES WILL REMAIN BELOW NORMAL THE
NEXT FEW DAYS. A DRYING AND WARMING TREND IS EXPECTED LATE IN THE
WEEK AS HIGH PRESSURE BECOMES REESTABLISHED TO THE SOUTH.
&&
.DISCUSSION...
LATEST RAP STREAMLINE ANALYSIS SHOWS THE MID-TROPOSPHERIC HIGH
POSITIONED NEAR THE FOUR CORNERS. FURTHER SOUTH...A WELL-DEFINED
INVERTED TROUGH IS APPARENT ACROSS SONORA WHILE THUNDERSTORMS
ASSOCIATED WITH AN MCS PERSIST EARLY THIS MORNING. BETWEEN THE TWO
SYSTEMS...THE STEERING FLOW IS GENERALLY SOUTHEASTERLY AROUND 15 KT.
ACROSS THE FORECAST AREA...SCATTERED SHOWERS HAVE REDEVELOPED ACROSS
THE LOWER DESERTS...INCLUDING PORTIONS OF THE PHOENIX METRO AREA.
ALTHOUGH CAPE IS GENERALLY LACKING AT THIS HOUR...WEAK VORTICITY AND
JET-FORCED ASCENT ALONG WITH REMNANT OUTFLOW BOUNDARIES ARE
CONTRIBUTING TO THE NOCTURNAL CONVECTION.
CLASSIC SETUP FOR ACTIVE WEATHER IS IN PLACE AND ALL SIGNS POINT TO
FAVORABLE CONDITIONS FOR ADDITIONAL STORM DEVELOPMENT AS EARLY AS
THIS MORNING ACROSS THE REGION. LATEST GPS-IPW AT TEMPE REGISTERED
AS HIGH AS 1.85 INCHES. MODELS INDICATE THAT THE ATMOSPHERE WILL
CONTINUE TO SATURATE AND ALONG WITH INCREASING DEEP LAYER
FLOW...STRONGER INSTABILITY AND SYNOPTIC ASCENT AHEAD OF THE
APPROACHING VORT MAX...SHOWERS AND THUNDERSTORMS WILL LIKELY BECOME
WIDESPREAD DURING THE AFTERNOON AND EVENING. GIVEN THE ANOMALOUSLY
(150-200% OF NORMAL) MOIST PROFILE...FLASH FLOODING WILL BE THE
PRIMARY THREAT AND A FLASH FLOOD WATCH HAS BEEN ISSUED FOR A LARGE
PORTION OF THE AREA. POPS WERE ALSO INCREASED TO AROUND 70 PERCENT
FOR THE PHOENIX AREA AND AS HIGH AS 80 PERCENT ACROSS THE HIGHER
TERRAIN OF SOUTHERN GILA COUNTY. GLOBAL AND CONVECTIVE ALLOWING
MODELS ARE STILL SOMEWHAT UNCERTAIN WITH REGARD TO THE EXACT SPEED
OF THE TROUGH AS IT LIFTS NORTHWARD THROUGH THE FORECAST AREA.
CONSEQUENTLY...THE POTENTIAL FOR HEAVY RAIN WILL OCCUR OVER A
RELATIVELY LONG TIME WINDOW...PERHAPS EVEN CONTINUING INTO WEDNESDAY
MORNING MAINLY FROM PHOENIX NORTHWARD. SOME LOCATIONS MAY SEE STORM
TOTALS IN EXCESS OF 1.0-1.5 INCHES.
AFOREMENTIONED VORT MAX WILL ACCELERATE SOMEWHAT WEDNESDAY AS IT
LIFTS NORTHEASTWARD INTO NORTHERN ARIZONA. BELOW NORMAL TEMPERATURES
ARE A GOOD BET GIVEN THE DEEP MOISTURE AND RESIDUAL RAIN-COOLED AIR.
HIGH TEMPERATURES WERE LOWERED INTO THE MID 90S FOR THE PHOENIX
AREA. BEST CHANCE FOR PRECIPITATION APPEARS TO BE ACROSS THE HIGHER
TERRAIN NORTH AND EAST OF PHOENIX. HOWEVER...A MOIST SOUTHWESTERLY
FLOW SUGGESTS THE POSSIBILITY OF BACK-BUILDING CELLS INTO THE LOWER
DESERTS AND POPS WERE INCREASED TO 50 PERCENT IN THESE AREAS.
A DRIER SOUTHWESTERLY FLOW WILL DEVELOP IN THE WAKE OF THE LOW
PRESSURE SYSTEM BY THURSDAY...WHICH WILL CONFINE THUNDERSTORMS
MAINLY TO THE HIGHER TERRAIN OF NORTHERN AND EASTERN AZ. A WARMING
AND DRYING TREND IS ALSO EXPECTED LATE IN THE WEEK AND INTO EARLY
NEXT WEEK AS THE MONSOON HIGH DRIFTS SOUTHWARD...GIVING WAY TO MORE
OF A WESTERLY FLOW.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
A MUCH WETTER PATTERN FOR THE NEXT 24 HOURS OR SO...WITH SCATTERED
TO WIDESPREAD SHOWERS AND THUNDERSTORMS ACROSS THE REGION...TOPS
GENERALLY 38-42KFT. EXPECT SCT-BKN CLOUD DECKS AOA 8000 FT...LOCAL
CIGS AS LOW AS 6000 FT AND VISIBILITY DOWN TO 4SM IN HEAVY RAIN WITH
STRONGER STORMS. ANTICIPATE STORM ACTIVITY TO PEAK DURING AFTERNOON
HOURS AND PERSIST THROUGH 05Z WEDNESDAY AS UPPER LEVEL DISTURBANCE
MOVES THROUGH THE AREA.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
DRIER AIR WILL FILTER INTO THE DISTRICT BEGINNING THURSDAY...WITH
MORE PREVALENT CLEAR SKIES AND LOWER HUMIDITIES OVER THE WEEKEND.
THE BEST CHANCES FOR RAINFALL THURSDAY AND FRIDAY WILL BE OVER GILA
COUNTY AS SOME RESIDUAL MOISTURE LINGERS OVER HIGHER TERRAIN. WITH
NEAR AVERAGE TEMPERATURES...AFTERNOON RELATIVE HUMIDITY VALUES
FALLING INTO A 25-40 PERCENT RANGE THURSDAY WILL DRY TOWARDS A 10-25
PERCENT RANGE BY THE WEEKEND. OVERNIGHT RECOVERY WILL BE GOOD TO
EXCELLENT. OUTSIDE OF ANY GUSTY THUNDERSTORM WINDS
THURSDAY...TYPICAL LIGHT SUMMER WINDS WILL PREVAIL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FLASH FLOOD WATCH FROM NOON MST TODAY THROUGH WEDNESDAY MORNING
AZZ020>028.
CA...FLASH FLOOD WATCH FROM NOON PDT TODAY THROUGH WEDNESDAY MORNING
CAZ031>033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION....MEYERS
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
310 AM MST TUE AUG 12 2014
...POTENTIAL FOR FLASH FLOODING TODAY AND TONIGHT ACROSS MUCH OF THE
AREA...
.SYNOPSIS...
MOISTURE LEVELS WILL CONTINUE TO INCREASE TODAY AHEAD OF AN
APPROACHING LOW PRESSURE SYSTEM. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TODAY AND TONIGHT ACROSS MUCH OF THE AREA. SOME STORMS WILL
BE CAPABLE OF PRODUCING VERY HEAVY RAIN AND AREAS OF FLOODING. WITH
THE MOIST CONDITIONS...TEMPERATURES WILL REMAIN BELOW NORMAL THE
NEXT FEW DAYS. A DRYING AND WARMING TREND IS EXPECTED LATE IN THE
WEEK AS HIGH PRESSURE BECOMES REESTABLISHED TO THE SOUTH.
&&
.DISCUSSION...
LATEST RAP STREAMLINE ANALYSIS SHOWS THE MID-TROPOSPHERIC HIGH
POSITIONED NEAR THE FOUR CORNERS. FURTHER SOUTH...A WELL-DEFINED
INVERTED TROUGH IS APPARENT ACROSS SONORA WHILE THUNDERSTORMS
ASSOCIATED WITH AN MCS PERSIST EARLY THIS MORNING. BETWEEN THE TWO
SYSTEMS...THE STEERING FLOW IS GENERALLY SOUTHEASTERLY AROUND 15 KT.
ACROSS THE FORECAST AREA...SCATTERED SHOWERS HAVE REDEVELOPED ACROSS
THE LOWER DESERTS...INCLUDING PORTIONS OF THE PHOENIX METRO AREA.
ALTHOUGH CAPE IS GENERALLY LACKING AT THIS HOUR...WEAK VORTICITY AND
JET-FORCED ASCENT ALONG WITH REMNANT OUTFLOW BOUNDARIES ARE
CONTRIBUTING TO THE NOCTURNAL CONVECTION.
CLASSIC SETUP FOR ACTIVE WEATHER IS IN PLACE AND ALL SIGNS POINT TO
FAVORABLE CONDITIONS FOR ADDITIONAL STORM DEVELOPMENT AS EARLY AS
THIS MORNING ACROSS THE REGION. LATEST GPS-IPW AT TEMPE REGISTERED
AS HIGH AS 1.85 INCHES. MODELS INDICATE THAT THE ATMOSPHERE WILL
CONTINUE TO SATURATE AND ALONG WITH INCREASING DEEP LAYER
FLOW...STRONGER INSTABILITY AND SYNOPTIC ASCENT AHEAD OF THE
APPROACHING VORT MAX...SHOWERS AND THUNDERSTORMS WILL LIKELY BECOME
WIDESPREAD DURING THE AFTERNOON AND EVENING. GIVEN THE ANOMALOUSLY
(150-200% OF NORMAL) MOIST PROFILE...FLASH FLOODING WILL BE THE
PRIMARY THREAT AND A FLASH FLOOD WATCH HAS BEEN ISSUED FOR A LARGE
PORTION OF THE AREA. POPS WERE ALSO INCREASED TO AROUND 70 PERCENT
FOR THE PHOENIX AREA AND AS HIGH AS 80 PERCENT ACROSS THE HIGHER
TERRAIN OF SOUTHERN GILA COUNTY. GLOBAL AND CONVECTIVE ALLOWING
MODELS ARE STILL SOMEWHAT UNCERTAIN WITH REGARD TO THE EXACT SPEED
OF THE TROUGH AS IT LIFTS NORTHWARD THROUGH THE FORECAST AREA.
CONSEQUENTLY...THE POTENTIAL FOR HEAVY RAIN WILL OCCUR OVER A
RELATIVELY LONG TIME WINDOW...PERHAPS EVEN CONTINUING INTO WEDNESDAY
MORNING MAINLY FROM PHOENIX NORTHWARD. SOME LOCATIONS MAY SEE STORM
TOTALS IN EXCESS OF 1.0-1.5 INCHES.
AFOREMENTIONED VORT MAX WILL ACCELERATE SOMEWHAT WEDNESDAY AS IT LIFTS
NORTHEASTWARD INTO NORTHERN ARIZONA. BELOW NORMAL TEMPERATURES ARE A
GOOD BET GIVEN THE DEEP MOISTURE AND RESIDUAL RAIN-COOLED AIR. HIGH
TEMPERATURES WERE LOWERED INTO THE MID 90S FOR THE PHOENIX AREA.
BEST CHANCE FOR PRECIPITATION APPEARS TO BE ACROSS THE HIGHER
TERRAIN NORTH AND EAST OF PHOENIX. HOWEVER...A MOIST SOUTHWESTERLY
FLOW SUGGESTS THE POSSIBILITY OF BACK-BUILDING CELLS INTO THE LOWER
DESERTS AND POPS WERE INCREASED TO 50 PERCENT IN THESE AREAS.
A DRIER SOUTHWESTERLY FLOW WILL DEVELOP IN THE WAKE OF THE LOW
PRESSURE SYSTEM BY THURSDAY...WHICH WILL CONFINE THUNDERSTORMS
MAINLY TO THE HIGHER TERRAIN OF NORTHERN AND EASTERN AZ. A WARMING
AND DRYING TREND IS ALSO EXPECTED LATE IN THE WEEK AND INTO EARLY
NEXT WEEK AS THE MONSOON HIGH DRIFTS SOUTHWARD...GIVING WAY TO MORE
OF A WESTERLY FLOW.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
THUNDERSTORMS HAVE MOSTLY ENDED OVER THE SOUTH CENTRAL DESERTS...AND
SINCE THE BOUNDARY LAYER HAS BECOME STABILIZED...THREAT FOR STORMS
WILL REMAIN LOW FOR THE REST OF THE EVENING. AS SUCH NO MENTION OF
THUNDER WILL MADE IN THE AREA TAFS TONIGHT. THERE STILL EXISTS THE
POSSIBILITY OF ENHANCED OUTFLOW WINDS MOVING THRU THE TERMINALS
THROUGH 10-11 PM OR SO AS THERE ARE STILL STORMS FIRING ON THE
FRINGES OF THE PHOENIX METRO AREA. AGAIN...CANNOT RULE OUT A STORM
AFFECTING THE DESERTS OVERNIGHT BUT CHANCES WILL BE MOSTLY 20
PERCENT OR LESS...AND CONFIDENCE WAY TOO LOW TO MENTION IN THE TAFS.
FOR THE REST OF TONIGHT EXPECT CONSIDERABLE MID/UPPER LEVEL CLOUD
DECKS...MUCH OF IT DEBRIS CLOUD FROM NEARBY CONVECTION. MOST BASES
WILL BE AOA 10K FEET. WINDS TO FAVOR AN EASTERLY COMPONENT WITH
OCCASIONAL GUSTS TO 20KT OR SO...MAYBE A BIT HIGHER.
AS MOISTURE INCREASES TONIGHT INTO THE DAY TUESDAY...AND AN UPPER
DISTURBANCE APPROACHES FROM THE SOUTH...EXPECT A WETTER...CLOUDIER
AND MORE UNSETTLED PERIOD WITH A GOOD CHANCE FOR SHOWERS OR EMBEDDED
THUNDERSTORMS. MAY SEE CIGS LOWER TO 6K FEET OR BELOW DURING THE
DAY...ESPECIALLY SHOULD A STRONGER STORM OR HEAVY SHOWER MOVE ACROSS
ONE OF THE TERMINALS. OF COURSE...GUSTY VARIABLE WINDS AND
RESTRICTED VIS DUE TO BLOWING DUST OR HEAVY RAIN IS A POSSIBILITY
TUESDAY. FOR NOW WILL SIMPLY MENTION VCSH IN THE TERMINALS STARTING
AT ABOUT 18Z BUT A THUNDERSTORM COULD CERTAINLY OCCUR.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
INCREASING CLOUDS AND CHANCES FOR TSRA/SHRA OVERNIGHT TONIGHT INTO
THE DAY TUESDAY AS MOISTURE INCREASES FROM THE SOUTHEAST. DUE TO
LOWER CONFIDENCE WILL NOT MENTION THUNDER IN THE TAFS TONIGHT...AND
WILL OPT TO GO WITH VCSH STARTING MID MORNING TUESDAY. SHOULD STORMS
DEVELOP...TAFS WILL NEED TO BE UPDATED FOR APPROPRIATE SKY/VIS AND
WIND CONDITIONS. WINDS SHOULD FAVOR THE SOUTH OR SOUTHEAST AT KIPL
AND KBLH NEXT 18-24 HOURS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
DRIER AIR WILL FILTER INTO THE DISTRICT BEGINNING THURSDAY...WITH
MORE PREVALENT CLEAR SKIES AND LOWER HUMIDITIES OVER THE WEEKEND. THE
BEST CHANCES FOR RAINFALL THURSDAY AND FRIDAY WILL BE OVER GILA
COUNTY AS SOME RESIDUAL MOISTURE LINGERS OVER HIGHER TERRAIN. WITH
NEAR AVERAGE TEMPERATURES...AFTERNOON RELATIVE HUMIDITY VALUES
FALLING INTO A 25-40 PERCENT RANGE THURSDAY WILL DRY TOWARDS A
10-25 PERCENT RANGE BY THE WEEKEND. OVERNIGHT RECOVERY WILL BE GOOD
TO EXCELLENT. OUTSIDE OF ANY GUSTY THUNDERSTORM WINDS
THURSDAY...TYPICAL LIGHT SUMMER WINDS WILL PREVAIL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FLASH FLOOD WATCH FROM NOON MST TODAY THROUGH WEDNESDAY MORNING
AZZ020>028.
CA...FLASH FLOOD WATCH FROM NOON PDT TODAY THROUGH WEDNESDAY MORNING
CAZ031>033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION....CB
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
310 AM MST MON AUG 11 2014
...POTENTIAL FOR FLASH FLOODING TODAY AND TONIGHT ACROSS MUCH OF THE
AREA...
.SYNOPSIS...
MOISTURE LEVELS WILL CONTINUE TO INCREASE TODAY AHEAD OF AN
APPROACHING LOW PRESSURE SYSTEM. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TODAY AND TONIGHT ACROSS MUCH OF THE AREA. SOME STORMS WILL
BE CAPABLE OF PRODUCING VERY HEAVY RAIN AND AREAS OF FLOODING. WITH
THE MOIST CONDITIONS...TEMPERATURES WILL REMAIN BELOW NORMAL THE
NEXT FEW DAYS. A DRYING AND WARMING TREND IS EXPECTED LATE IN THE
WEEK AS HIGH PRESSURE BECOMES REESTABLISHED TO THE SOUTH.
&&
.DISCUSSION...
LATEST RAP STREAMLINE ANALYSIS SHOWS THE MID-TROPOSPHERIC HIGH
POSITIONED NEAR THE FOUR CORNERS. FURTHER SOUTH...A WELL-DEFINED
INVERTED TROUGH IS APPARENT ACROSS SONORA WHILE THUNDERSTORMS
ASSOCIATED WITH AN MCS PERSIST EARLY THIS MORNING. BETWEEN THE TWO
SYSTEMS...THE STEERING FLOW IS GENERALLY SOUTHEASTERLY AROUND 15 KT.
ACROSS THE FORECAST AREA...SCATTERED SHOWERS HAVE REDEVELOPED ACROSS
THE LOWER DESERTS...INCLUDING PORTIONS OF THE PHOENIX METRO AREA.
ALTHOUGH CAPE IS GENERALLY LACKING AT THIS HOUR...WEAK VORTICITY AND
JET-FORCED ASCENT ALONG WITH REMNANT OUTFLOW BOUNDARIES ARE
CONTRIBUTING TO THE NOCTURNAL CONVECTION.
CLASSIC SETUP FOR ACTIVE WEATHER IS IN PLACE AND ALL SIGNS POINT TO
FAVORABLE CONDITIONS FOR ADDITIONAL STORM DEVELOPMENT AS EARLY AS
THIS MORNING ACROSS THE REGION. LATEST GPS-IPW AT TEMPE REGISTERED
AS HIGH AS 1.85 INCHES. MODELS INDICATE THAT THE ATMOSPHERE WILL
CONTINUE TO SATURATE AND ALONG WITH INCREASING DEEP LAYER
FLOW...STRONGER INSTABILITY AND SYNOPTIC ASCENT AHEAD OF THE
APPROACHING VORT MAX...SHOWERS AND THUNDERSTORMS WILL LIKELY BECOME
WIDESPREAD DURING THE AFTERNOON AND EVENING. GIVEN THE ANOMALOUSLY
(150-200% OF NORMAL) MOIST PROFILE...FLASH FLOODING WILL BE THE
PRIMARY THREAT AND A FLASH FLOOD WATCH HAS BEEN ISSUED FOR A LARGE
PORTION OF THE AREA. POPS WERE ALSO INCREASED TO AROUND 70 PERCENT
FOR THE PHOENIX AREA AND AS HIGH AS 80 PERCENT ACROSS THE HIGHER
TERRAIN OF SOUTHERN GILA COUNTY. GLOBAL AND CONVECTIVE ALLOWING
MODELS ARE STILL SOMEWHAT UNCERTAIN WITH REGARD TO THE EXACT SPEED
OF THE TROUGH AS IT LIFTS NORTHWARD THROUGH THE FORECAST AREA.
CONSEQUENTLY...THE POTENTIAL FOR HEAVY RAIN WILL OCCUR OVER A
RELATIVELY LONG TIME WINDOW...PERHAPS EVEN CONTINUING INTO WEDNESDAY
MORNING MAINLY FROM PHOENIX NORTHWARD. SOME LOCATIONS MAY SEE STORM
TOTALS IN EXCESS OF 1.0-1.5 INCHES.
AFOREMENTIONED VORT MAX WILL ACCELERATE SOMEWHAT WEDNESDAY AS IT LIFTS
NORTHEASTWARD INTO NORTHERN ARIZONA. BELOW NORMAL TEMPERATURES ARE A
GOOD BET GIVEN THE DEEP MOISTURE AND RESIDUAL RAIN-COOLED AIR. HIGH
TEMPERATURES WERE LOWERED INTO THE MID 90S FOR THE PHOENIX AREA.
BEST CHANCE FOR PRECIPITATION APPEARS TO BE ACROSS THE HIGHER
TERRAIN NORTH AND EAST OF PHOENIX. HOWEVER...A MOIST SOUTHWESTERLY
FLOW SUGGESTS THE POSSIBILITY OF BACK-BUILDING CELLS INTO THE LOWER
DESERTS AND POPS WERE INCREASED TO 50 PERCENT IN THESE AREAS.
A DRIER SOUTHWESTERLY FLOW WILL DEVELOP IN THE WAKE OF THE LOW
PRESSURE SYSTEM BY THURSDAY...WHICH WILL CONFINE THUNDERSTORMS
MAINLY TO THE HIGHER TERRAIN OF NORTHERN AND EASTERN AZ. A WARMING
AND DRYING TREND IS ALSO EXPECTED LATE IN THE WEEK AND INTO EARLY
NEXT WEEK AS THE MONSOON HIGH DRIFTS SOUTHWARD...GIVING WAY TO MORE
OF A WESTERLY FLOW.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
THUNDERSTORMS HAVE MOSTLY ENDED OVER THE SOUTH CENTRAL DESERTS...AND
SINCE THE BOUNDARY LAYER HAS BECOME STABILIZED...THREAT FOR STORMS
WILL REMAIN LOW FOR THE REST OF THE EVENING. AS SUCH NO MENTION OF
THUNDER WILL MADE IN THE AREA TAFS TONIGHT. THERE STILL EXISTS THE
POSSIBILITY OF ENHANCED OUTFLOW WINDS MOVING THRU THE TERMINALS
THROUGH 10-11 PM OR SO AS THERE ARE STILL STORMS FIRING ON THE
FRINGES OF THE PHOENIX METRO AREA. AGAIN...CANNOT RULE OUT A STORM
AFFECTING THE DESERTS OVERNIGHT BUT CHANCES WILL BE MOSTLY 20
PERCENT OR LESS...AND CONFIDENCE WAY TOO LOW TO MENTION IN THE TAFS.
FOR THE REST OF TONIGHT EXPECT CONSIDERABLE MID/UPPER LEVEL CLOUD
DECKS...MUCH OF IT DEBRIS CLOUD FROM NEARBY CONVECTION. MOST BASES
WILL BE AOA 10K FEET. WINDS TO FAVOR AN EASTERLY COMPONENT WITH
OCCASIONAL GUSTS TO 20KT OR SO...MAYBE A BIT HIGHER.
AS MOISTURE INCREASES TONIGHT INTO THE DAY TUESDAY...AND AN UPPER
DISTURBANCE APPROACHES FROM THE SOUTH...EXPECT A WETTER...CLOUDIER
AND MORE UNSETTLED PERIOD WITH A GOOD CHANCE FOR SHOWERS OR EMBEDDED
THUNDERSTORMS. MAY SEE CIGS LOWER TO 6K FEET OR BELOW DURING THE
DAY...ESPECIALLY SHOULD A STRONGER STORM OR HEAVY SHOWER MOVE ACROSS
ONE OF THE TERMINALS. OF COURSE...GUSTY VARIABLE WINDS AND
RESTRICTED VIS DUE TO BLOWING DUST OR HEAVY RAIN IS A POSSIBILITY
TUESDAY. FOR NOW WILL SIMPLY MENTION VCSH IN THE TERMINALS STARTING
AT ABOUT 18Z BUT A THUNDERSTORM COULD CERTAINLY OCCUR.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
INCREASING CLOUDS AND CHANCES FOR TSRA/SHRA OVERNIGHT TONIGHT INTO
THE DAY TUESDAY AS MOISTURE INCREASES FROM THE SOUTHEAST. DUE TO
LOWER CONFIDENCE WILL NOT MENTION THUNDER IN THE TAFS TONIGHT...AND
WILL OPT TO GO WITH VCSH STARTING MID MORNING TUESDAY. SHOULD STORMS
DEVELOP...TAFS WILL NEED TO BE UPDATED FOR APPROPRIATE SKY/VIS AND
WIND CONDITIONS. WINDS SHOULD FAVOR THE SOUTH OR SOUTHEAST AT KIPL
AND KBLH NEXT 18-24 HOURS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
DRIER AIR WILL FILTER INTO THE DISTRICT BEGINNING THURSDAY...WITH
MORE PREVALENT CLEAR SKIES AND LOWER HUMIDITIES OVER THE WEEKEND. THE
BEST CHANCES FOR RAINFALL THURSDAY AND FRIDAY WILL BE OVER GILA
COUNTY AS SOME RESIDUAL MOISTURE LINGERS OVER HIGHER TERRAIN. WITH
NEAR AVERAGE TEMPERATURES...AFTERNOON RELATIVE HUMIDITY VALUES
FALLING INTO A 25-40 PERCENT RANGE THURSDAY WILL DRY TOWARDS A
10-25 PERCENT RANGE BY THE WEEKEND. OVERNIGHT RECOVERY WILL BE GOOD
TO EXCELLENT. OUTSIDE OF ANY GUSTY THUNDERSTORM WINDS
THURSDAY...TYPICAL LIGHT SUMMER WINDS WILL PREVAIL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FLASH FLOOD WATCH FROM NOON MST TODAY THROUGH WEDNESDAY MORNING
AZZ020>028.
CA...FLASH FLOOD WATCH FROM NOON PDT TODAY THROUGH WEDNESDAY MORNING
CAZ031>033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION....CB
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
958 AM EDT TUE AUG 12 2014
.SYNOPSIS...
LOW PRESSURE OVER LAKE HURON EDGES NORTH TO NEAR JAMES BAY CANADA AS
NEW LOW PRESSURE FORMS ALONG THE COLD FRONT PUSHING THROUGH NEW
JERSEY EARLY WEDNESDAY. THEREAFTER...LOW PRESSURE IN QUEBEC
DOMINATES THROUGH THURSDAY WITH MIDWEST HIGH PRESSURE EVENTUALLY
MOVING TO THE MID ATLANTIC COAST FRIDAY. ANOTHER COLD FRONTAL
PASSAGE IS POSSIBLE LATE SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE SURFACE WARM FRONT IS STILL DRAPED ACROSS CENTRAL NORTH
CAROLINA WITH THE OCCLUSION SLOWLY MOVING INTO WESTERN
PENNSYLVANIA. THE WARM FRONT HAS BEEN SLOW TO MOVE NORTHWARD AS
THE INITIAL SHOT OF RAIN THIS MORNING AND THE SOUTHEAST FLOW AHEAD
OF THE FRONT HAS INCREASED EARLY PREVENTING A QUICKER MOVEMENT.
THE WARM FRONT TIMING PLAYS A HUGE FACTOR IN HOW QUICKLY THE
STRONGER OVER-RUNNING AND POSSIBLE CONVECTIVE ACTIVITY RE-ENTERS
THE REGION.
OF THE HI-RES MODELS, THE HRRR SEEMS TO HAVE THE BEST HANDLE ON
THE PRECIPITATION SHIELD THIS MORNING. IT SHOWS A DECENT AMOUNT OF
DRYING ACROSS THE CENTRAL AND SOUTHERN PORTIONS OF THE CWA BEFORE
FILLING BACK IN FROM THE SOUTH-SOUTHWEST...WARM FRONT/THETA-E
UPGLIDE INDUCED. THAT BEING SAID, DID SCALE BACK POPS FOR THE NEXT
FEW HOURS ACROSS A THE SOUTHEASTERN HALF OF THE CWA BEFORE RAMPING
THEM UP AGAIN LATER THIS AFTERNOON.
OTHERWISE, THE STRETCH OF NICE WEATHER HAS COME TO AN END TODAY
AS OUR REGION BECOMES MORE AND MORE UNDER THE INFLUENCE OF AN
AMPLIFYING UPPER-LEVEL TROUGH TO THE WEST THAT CLOSES OFF. THIS
FEATURE WILL DRIVE DOWNSTREAM WAA AND THETA-E ADVECTION THROUGH
THE DAY, WHICH WILL BE AIDED BY AN UPTICK IN THE WIND FIELD. THE
FORECAST CHALLENGE REVOLVES AROUND THE TIMING OF THE SHOWERS WITH
AN EASTWARD EXTENT AS THE MID LEVEL RIDGE DEPARTS TO THE EAST, AND
ALSO THE EXTENT OF WINDS AND TEMPERATURES. IT DOES APPEAR HOWEVER
THE STRONGER LIFT ENHANCED BY AN INCREASING LOW-LEVEL JET ARRIVES
LATER IN THE DAY AND THEN TONIGHT.
THE SYNOPTIC SETUP WILL RESULT IN A SOUTHEASTERLY LOW-LEVEL FLOW
DOMINATING OUR REGION TODAY, HOWEVER THIS DOES VEER TO THE SOUTH AND
SOUTHWEST WITH HEIGHT. THIS WILL HELP TO ENHANCE THE WAA, WITH A
WARM FRONT TO OUR SOUTH TRYING TO LIFT INTO THE DELMARVA. THIS WARM
FRONT PROBABLY DOES NOT GET ANY FARTHER THAN PORTIONS OF THE
DELMARVA. THIS WILL MAINTAIN THE FLOW OFF THE OCEAN AND ALSO RESULT
IN DEEPER MOISTURE TRANSPORT AS THE ISENTROPIC LIFT INCREASES SOME
THROUGH THE DAY. THIS WILL RESULT IN SOME SHOWERS MOVING THROUGH
THIS MORNING ESPECIALLY THE WESTERN ZONES, THEN PERHAPS A
BREAK FOR PORTIONS OF THE AREA BEFORE STRONGER LIFT STARTS TO ARRIVE
BY LATE IN THE AFTERNOON. THE FORECAST SOUNDINGS OVERALL SHOW A
MOISTENING ENVIRONMENT WHICH WILL TEND TO HOLD DOWN THE INSTABILITY.
THE ONSHORE FLOW WILL ALSO TEND TO LIMIT THE SURFACE BASED
INSTABILITY OVERALL. THEREFORE, ANY THUNDER SHOULD GENERALLY BE
LIMITED AND PROBABLY NOT OCCUR UNTIL LATER THIS AFTERNOON WHEN THE
SOUNDINGS SHOW MUCH DEEPER MOISTURE WITHIN A HIGHER SHEAR/LOW CAPE
SETUP DEVELOPING. THERE WILL ALSO BE AN UPSLOPE COMPONENT, WHICH CAN
ENHANCE THE RAINFALL TOWARD OUR WEST/NORTHWEST ZONES.
A SPOT TO WATCH THOUGH IS CLOSE TO THE WARM FRONT AS SHEAR WILL BE
ENHANCED HERE WITH THE POTENTIAL FOR SOME INCOMING CONVECTION TO
OVERRUN THIS BOUNDARY. IT DOES APPEAR THAT THE VERTICAL SHEAR COULD
BE SUFFICIENT ENOUGH TO COMPENSATE FOR THE LOWER INSTABILITY AND
ALLOW FOR STORM ORGANIZATION. HOWEVER, THE CONVECTION MAY TEND TO BE
LOW-TOPPED AND LOCALLY GUSTY CONVECTIVE WINDS CANNOT BE RULED OUT
LATER THIS AFTERNOON ESPECIALLY SOUTH. WE WILL HAVE TO SEE IF A DRY
SLOT IS ABLE TO ALLOW FOR MORE BREAKS OF SUNSHINE. ANY STRONGER
CONVECTIVE CELLS SHOULD TEND TO BE IN THE FORM OF LINE SEGMENTS,
ALTHOUGH A LOW-TOPPED CELL WITH SUPERCELL STRUCTURE /BRIEF SPIN-UP/
IS POSSIBLE MAINLY NEAR THE WARM FRONT.
AS FOR HIGH TEMPERATURES, WE USED A NAM/GFS MOS BLEND WITH SOME
DOWNWARD ADJUSTMENTS BASED ON THE IDEA OF CLOUD COVER AND ALSO THE
ONSHORE FLOW KEEPING THE SURFACE TEMPERATURES A BIT COOLER. THE
PRESSURE GRADIENT IS FORECAST TO TIGHTEN SOME THROUGH THE DAY,
RESULTING IN SOME INCREASE OF THE LOW-LEVEL WIND FIELD. WHILE DEEP
MIXING SHOULD NOT OCCUR, THE GRADIENT WIND WITHIN A SOUTHEASTERLY
LOW-LEVEL FETCH SHOULD RESULT IN SOME GUSTINESS AT TIMES MAINLY
THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
A STRONG UPPER-LEVEL TROUGH WILL CONTINUE TO SWING ACROSS THE GREAT
LAKES AND OHIO VALLEY TONIGHT. THIS FEATURE LOOKS TO TAKE ON A
NEGATIVE TILT AS IT APPROACHES THE MID ATLANTIC REGION OVERNIGHT.
OVERALL THOUGH, THE LARGE SCALE LIFT WILL BE STRONGEST TONIGHT AS IT
WORKS IN TANDEM WITH A HIGH PW ENVIRONMENT. THE WARM FRONT MAY NOT
MAKE MUCH NORTHWARD PROGRESS AS THE INCOMING COLD FRONT PROBABLY
OCCLUDES, HOWEVER SOME INCREASE IN THE INSTABILITY MAY OCCUR FOR AT
LEAST LOW-TOPPED CONVECTION WHICH COULD BE STRONG ENOUGH TO RESULT
IN LOCALLY STRONG WIND GUSTS. THE SETUP LOOKS NEARLY LIKE A
LOW-TOPPED CONVECTIVE LINE OR LINE SEGMENTS DEVELOPING AND SHIFTING
EASTWARD ACROSS MUCH OF THE AREA DURING THE NIGHT. THIS MAY DELIVER
THE MORE INTENSE DOWNPOURS AS IT IS DRIVEN BY A STRONGER LOW-LEVEL
JET WITHIN AN AIRMASS CHARACTERIZED BY PW VALUES BETWEEN 2.0 AND 2.4
INCHES. THERE COULD BE SOME ENHANCEMENT TO THE RAINFALL AND
LOW-LEVEL SHEAR WITH A SURFACE LOW DEVELOPING NEAR THE TRIPLE POINT
GENERALLY ACROSS OUR SOUTHERN ZONES.
THE DOWNPOURS THROUGH TONIGHT MAY RESULT IN SOME TIMES OF POOR
DRAINAGE AND/OR PONDING OF WATER ON SOME ROADWAYS, HOWEVER THE FLASH
FLOOD AND HEADWATER GUIDANCE IS RATHER HIGH ACROSS NEARLY THE ENTIRE
AREA. THE MAIN CONCERN IS HIGH RAINFALL RATES ESPECIALLY WITHIN THE
URBAN CORRIDOR AND TERRAIN LOCATIONS. OVERALL THOUGH ANY FLOOD
THREAT SHOULD BE LOCALIZED AND THEREFORE WE WILL HOLD OFF ON ANY
FLASH FLOOD WATCHES ATTM. THIS WILL BE RE-EXAMINED DURING THE DAY
TODAY. WE MAINTAINED CATEGORICAL POPS ACROSS MUCH OF THE AREA, WITH
SOME DECREASE INDICATED FROM SOUTHWEST TO NORTHEAST TOWARD DAYBREAK.
AS FOR TEMPERATURES, WE MAINLY USED AN EVEN NAM/GFS MOS BLEND.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
500MB: THE GENERAL TROUGH OVER THE EASTERN UNITED STATES TO START
THE PERIOD MAY LINGER NEXT WEEKEND AFTER WHICH A RIDGE MAY BUILD
OVER THE EASTERN USA EARLY NEXT WEEK.
TEMPERATURES: NEAR NORMAL DURING THE DAY WEDNESDAY THEN CALENDAR DAY
AVERAGES THURSDAY-SATURDAY 3 TO 6 DEGREES BELOW NORMAL EACH DAY
MAY WARM SEVERAL DEGREES ABOVE NORMAL EARLY NEXT WEEK?
FORECAST BASIS: UNLESS OTHERWISE NOTED THE LONG TERM PERIOD OF THIS
FORECAST IS GENERALLY BASED ON A 50 50 BLEND OF THE 00Z/12 NAM/GFS
MOS FOR THE PERIOD WEDNESDAY - THURSDAY... THE 00Z/12 GFS MOS
THURSDAY NIGHT AND FRIDAY AND THEN THEREAFTER (FRIDAY NIGHT ONWARD) THE
0543Z/12 WPC GRIDDED GUIDANCE. THIS WAS CHECKED AGAINST THE 00Z/12
ECMWF TO SEE IF WE`RE IN THE BALLPARK WITH ECMWF 18Z 2METER
TEMPERATURES. THE PRECIPITATION PROBABILITY GUIDANCE IS CHECKED
AGAINST THE 21Z/11 SREF POPS FOR .01 IN 3 HRS THROUGH 12Z FRIDAY
AND THEREAFTER THE 00Z/12 GEFS 6HR POPS FOR 0.05.
WEDNESDAY...LEFTOVERS DEPART NORTHEASTWARD WITH A CHANCE OF A NARROW
LINE OF LOW TOP CONVECTION DEVELOPING IN THE LEFTOVER HIGH PWAT
AIR ACROSS NJ/DE MIDDAY...THEN DRYING OUT DURING THE AFTN AS WEST
WINDS GUST 20 MPH. BLENDED 00Z/12 GFS/NAM GUIDANCE. COOLER AT NIGHT.
THURSDAY...THERE IS A SMALL CHC OF A SHOWER OR SPRINKLE IN THE
HILLS OF NW NJ AND AND E PA MIDDAY BEFORE DRYING DISSIPATES ANY
BRIEF AND ESSENTIALLY INCONSEQUENTIAL SHOWERS. OTHERWISE NICE.
WEST WIND GUSTS 15 T0 20 MPH.
FRIDAY/SATURDAY...CLEAR TO PC...MOST OF THE CLOUDS DIURNALLY
DRIVEN. LIGHT WIND AND COOL NIGHTS AS THE GENERALLY COOLER THAN
NORMAL START TO AUGUST CONTINUES.
SUNDAY...WARM AIR ADVECTION CLOUDS AND MAYBE A PERIOD OF SHOWERS
AND THUNDERSTORMS AHEAD OF ANOTHER POSSIBLE COLD FRONT. CONFIDENCE
FOR THIS POSSIBLE NEXT COLD FRONT IS BELOW AVERAGE SINCE THE 00Z/12
GEFS TEMPERATURE CONFIDENCE IMAGERY FOR WARMER THAN OUR PHI FCST
TEMPS IS A BIT ABOVE AVERAGE. IN OTHER WORDS...MODEL SOLUTIONS ARE
NOT IN AGREEMENT FOR SUNDAY. THE ECMWF SECONDARY SHORT WAVE
PASSAGE THIS WEEKEND MAY BE TOO ROBUST. A WEAKER ECMWF SOLUTION
PERMITS A DRY NICE SUMMER WEEKEND.
MONDAY...P.C. AND MAYBE BEGINNING A WARMER MORE SUMMERY WEEK?
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TODAY...VFR CEILINGS LOWERING TO MVFR. THERE COULD BE TIMES THOUGH
LATE THIS MORNING AND EARLY THIS AFTERNOON WHERE ANY MVFR CEILINGS
RISE BACK TO VFR. SHOWERS WILL OVERSPREAD THE AREA THROUGH THE DAY,
WITH THE HEAVIER INTENSITY PROBABLY NOT OCCURRING UNTIL THIS
AFTERNOON. THIS WILL RESULT IN MVFR/IFR VISIBILITIES AT TIMES. ANY
IFR CEILINGS LATER IN THE DAY SHOULD BE LOCAL/BRIEF. SOUTHEASTERLY
WINDS INCREASING TO 10-15 KNOTS, WITH SOME GUSTS TO AROUND 20 KNOTS
MAINLY THIS AFTERNOON. THE GUSTINESS MAY BE MORE NOTED AT KILG AND
KACY.
TONIGHT...MVFR /POSSIBLE IFR CEILINGS FOR A TIME/ WITH SHOWERS AND
SOME THUNDERSTORMS. THERE WILL BE MODERATE TO HEAVY RAIN AT TIMES,
RESULTING IN GREATLY REDUCED VISIBILITIES. SOME THUNDERSTORMS COULD
BE IN THE FORM OF A LINE, WITH THE POTENTIAL FOR GUSTY WINDS.
SOUTHEASTERLY WINDS GENERALLY AROUND 10 KNOTS, HOWEVER THERE COULD
BE SOME LOCAL GUSTINESS ESPECIALLY CLOSER TO THE COAST IF ENOUGH
MIXING CAN BE MAINTAINED.
OUTLOOK...
WEDNESDAY...ANY LEFTOVER MVFR OR IFR CIGS SHOULD QUICKLY BECOME VFR
CIGS WITH A CHANCE OF BRIEF MVFR CONDITION SHOWERS AND THUNDERSTORMS...
ESPECIALLY 12Z-17Z. GRADIENT WEST WIND GUST 20 KT.
THURSDAY THROUGH SATURDAY...MAINLY VFR. SMALL CHANCE OF A LIGHT
SHOWER IN E PA OR NW NJ MIDDAY THURSDAY. GRADIENT WEST WIND GUST
20 KT THURSDAY AND 15 KT FRIDAY WITH EVEN LESS WESTERLY WIND
SATURDAY WHEN AFTERNOON COASTAL OCEAN AND BAY BREEZES PROBABLY
OCCUR.
&&
.MARINE...
THE PRESSURE GRADIENT WILL TIGHTEN TODAY INTO TONIGHT AHEAD OF AN
AMPLIFYING UPPER-LEVEL TROUGH. THIS WILL ALLOW FOR THE SURFACE WINDS
TO INCREASE WITH SOME ENHANCEMENT POSSIBLE PARTICULARLY UP DELAWARE
BAY. THE SOUNDINGS IN GENERAL INDICATE 25-30 KNOTS IN GUSTS AT THE
SURFACE AT TIMES, PROVIDED ENOUGH MIXING OCCURS. THE GUSTINESS IS
EXPECTED TO START DIMINISHING LATER THIS EVENING AS THE LOW-LEVEL
JET STARTS TO SHIFT EAST AHEAD OF AN ARRIVING COLD FRONT. THEREFORE,
WE WILL MAINTAIN THE END TIME OF THE SMALL CRAFT ADVISORY FOR
DELAWARE BAY AS IS /03Z THIS EVENING/. THE OCEAN ADVISORY RUNS RIGHT
THROUGH TONIGHT. THE STRENGTHENING FLOW WILL ALSO BUILD THE SEAS
ESPECIALLY ON THE COASTAL WATERS, AND WE WENT WITHIN A FOOT OF THE
WAVEWATCH GUIDANCE. IT APPEARS THAT SOME GUIDANCE THAT INDICATES
SOME NEAR GALE FORCE GUSTS TONIGHT IS PROBABLY OVERDONE WITH TO DEEP
OF A MIXING LAYER. THERE WILL BE THE CHC OF SOME THUNDERSTORMS
MAINLY LATE THIS AFTERNOON AND TONIGHT, WHICH COULD PRODUCE LOCALLY
ENHANCED WIND GUSTS.
OUTLOOK...
WEDNESDAY...WAVE HEIGHTS ARE ANTICIPATED TO REMAIN AROUND OR JUST
ABOVE 5 FEET. WIND SPEEDS MAY AGAIN INCREASE IN THE WEST NORTHWEST
FLOW ON WEDNESDAY AFTERNOON. THEREFORE, WE CONTINUE THE SMALL CRAFT
ADVISORY ON OUR OCEAN WATERS UNTIL 600 PM WEDNESDAY. IT MAY NEED
TO BE EXTENDED, IN TIME.
WEDNESDAY NIGHT...SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE.
THURSDAY THROUGH SATURDAY...NO MARINE HEADLINES ARE ANTICIPATED.
&&
.TIDES/COASTAL FLOODING...
A CONTINUED EAST TO SOUTHEAST SURFACE FLOW SHOULD MAINTAIN THE
POTENTIAL FOR AT LEAST SOME LOCALIZED MINOR TIDAL FLOODING AROUND
TONIGHTS HIGH TIDE. THERE IS SOME UNCERTAINTY WHETHER OR NOT THE
DEPARTURES BECOME HIGH ENOUGH TO ALLOW THE WATER LEVELS TO REACH
OUR ADVISORY CRITERIA. AS A RESULT, WE OPTED TO HOLD OFF ON
ISSUING AN ADVISORY ATTM AND THE DEPARTURES WILL BE MONITORED
THROUGH THE DAY.
&&
.RIP CURRENTS...
DESPITE A DECREASED WAVE PERIOD TODAY, AN EAST TO SOUTHEAST WIND
WILL INCREASE TO 15-25 MPH AND SEAS IN THE SURF ZONE WILL BE 3-5
FEET. AS A RESULT, THERE IS A MODERATE RISK OF DANGEROUS RIP
CURRENTS THROUGH TONIGHT FOR BOTH THE NEW JERSEY AND DELAWARE
BEACHES.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR ANZ452>455.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 6 PM EDT
WEDNESDAY FOR ANZ450-451.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ430-
431.
&&
$$
SYNOPSIS...DRAG
NEAR TERM...GORSE/HEAVENER
SHORT TERM...GORSE
LONG TERM...DRAG
AVIATION...DRAG/GORSE/HEAVENER
MARINE...DRAG/GORSE
TIDES/COASTAL FLOODING...
RIP CURRENTS...
AREA FORECAST DISCUSSION...UPDATED
NWS COLUMBIA SC
1117 AM EDT TUE AUG 12 2014
.SYNOPSIS...
A PRESSURE TROUGH WILL LINGER IN THE FORECAST AREA TODAY AHEAD OF
AN APPROACHING COLD FRONT. THE FRONT WILL MOVE INTO THE AREA LATE
TONIGHT AND EXTEND ALONG THE COAST WEDNESDAY. SHOWERS AND
THUNDERSTORMS EXPECTED THIS AFTERNOON AND EVENING...THEN DRIER
WEATHER SHOULD FOLLOW THE FRONT FOR THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MORNING STRATUS AND FOG ACROSS THE AREA HAS LIFTED WITH
TEMPERATURES ALREADY PUSHING INTO MID 80S WITH DEWPOINTS IN THE
MID 70S. VISIBLE SATELLITE IMAGERY SHOWING SOME CUMULUS CLOUDS
BEGINNING TO FORM AS CONVECTIVE TEMPERATURES ARE BEING REACHED.
MESOANALYSIS INDICATES PRECIPITABLE WATER VALUES STILL AROUND 2
INCHES THIS MORNING WHICH ALONG WITH DEWPOINTS IN THE 70S AND
SURFACE HEATING SHOULD LEAD TO AFTERNOON SHOWERS AND THUNDERSTORMS
AS AN UPPER TROUGH MOVES CLOSER TO THE REGION. WATER VAPOR IMAGERY
ALSO SHOWING DRIER AIR WILL WORK INTO THE REGION FROM THE WEST
LATE AFTERNOON AND EVENING WHICH COULD SUPPORT THE THREAT FOR
ISOLATED STRONG TO POSSIBLE SEVERE STORMS WITH DAMAGING WIND GUSTS
WITHIN MULTICELL SEGMENTS. HI-RES MODELS AND HRRR SHOWING STORMS
DEVELOPING OVER THE AREA MID AFTERNOON AND SHIFTING EASTWARD
ACROSS THE FORECAST AREA INTO EARLY EVENING AND WILL CONTINUE THE
LOW END LIKELY POPS FOR MUCH OF THE FORECAST AREA. MAX
TEMPERATURES EXPECTED IN THE LOWER 90S WITH HEAT INDICES CLOSE TO
100 DEGREES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
THE MODELS DISPLAY THE WEAKENING COLD FRONT IN THE COASTAL PLAIN
WEDNESDAY AND ALONG THE COAST WEDNESDAY NIGHT. ANY CONVERGENCE
ASSOCIATED WITH THE FRONT NEAR THE EAST PART OF THE FORECAST AREA
SHOULD BE WEAK WITH H85 WESTERLY FLOW. THE MODELS ARE CONSISTENT
WITH JUST SHALLOW MOISTURE. ALL THE NAM AND GFS MOS HAVE POPS
LESS THAN 20 PERCENT. SUNSHINE AND DOWNSLOPE FLOW WILL RESULT IN
WARM TEMPERATURES WEDNESDAY BUT RELATIVE HUMIDITIES WILL BE LOWER
THAN WHAT WE HAVE EXPERIENCED LATELY. THE TEMPERATURE GUIDANCE WAS
CLOSE WITH HIGHS MAINLY IN THE LOWER 90S. USED THE GUIDANCE
CONSENSUS FOR THE LOWS WEDNESDAY NIGHT. EXPECT TEMPERATURES WILL
FALL INTO THE MIDDLE AND UPPER 60S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
THE GFS AND ECMWF SHOW THE REMNANTS OF THE COLD FRONT NEAR THE
FORECAST AREA THURSDAY AND FRIDAY WITH WEAK TROUGHING.
HOWEVER...DEEP MOISTURE REMAINS SUPPRESSED EAST OF THE AREA AHEAD
OF THE EAST COAST UPPER TROUGH. THE GFS...ECMWF...AND EKD MOS HAVE
POPS LESS THAN 20 PERCENT. MOISTURE MAY INCREASE BEGINNING
SATURDAY BUT SHOULD REMAIN LIMITED BECAUSE BOTH THE GFS AND ECMWF
DISPLAY SURFACE RIDGING EXTENDING FROM THE ATLANTIC WESTWARD ALONG
THE GULF COAST. THE GFS...ECWMF...AND EKD MOS HAVE POPS 20 TO 30
PERCENT SATURDAY THROUGH MONDAY WITH THE HIGHER POPS MAINLY
MONDAY. THE GUIDANCE HAS TEMPERATURES NEAR CLIMATOLOGY THROUGH THE
MEDIUM-RANGE PERIOD.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
MORNING FOG/STRATUS HAS LIFTED AND CONDITIONS AT ALL TERMINALS
HAVE RETURNED TO VFR. SCATTERED CONVECTION WILL DEVELOP BY LATE
AFTERNOON AHEAD OF AN APPROACHING COLD FRONT. WILL USE VCSH FOR
ALL TAF SITES FROM AROUND 20Z TO AROUND 03Z THIS EVENING...BUT
HAVE SOME LOW CONFIDENCE WITH TIMING AND EXTENT OF THUNDER. SOME
MVFR FOG POSSIBLE BEFORE DAWN WEDNESDAY MORNING...BUT NOT ENOUGH
CONFIDENCE TO MENTION AT THIS TIME.
EXTENDED AVIATION OUTLOOK...POSSIBLE MVFR RESTRICTIONS EARLY
WEDNESDAY MORNING. OTHERWISE NO SIGNIFICANT RESTRICTIONS EXPECTED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
521 AM MDT TUE AUG 12 2014
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 235 AM MDT TUE AUG 12 2014
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW HIGHLY AMPLIFIED
RIDGE CENTERED OVER THE CENTRAL ROCKIES EXTENDING WELL INTO THE
CANADIAN ROCKIES. THE EASTERN EXTENT OF THIS RIDGE HAS SHIFTED OVER
OUR CWA...WITH THE MAIN STORM TRACK NOW WELL EAST. MONSOONAL PLUME
IS ALSO ORIENTATED MORE OVER THE GREAT BASIN THAT CENTRAL ROCKIES
WITH LITTLE IN THE WAY OF UPSTREAM ACTIVITY OVER THE NORTHERN PLAINS.
AT THE SURFACE HIGH PRESSURE REMAINS IN PLACE THE CENTRAL AND HIGH
PLAINS.
WITH H5 RIDGE NOW HOLDING MUCH MORE INFLUENCE ON WX OVER OUR
CWA...DRY CONDITIONS SHOULD CONTINUE THROUGH AT LEAST WEDNESDAY
AFTERNOON. GUIDANCE HAS SHIFTED TRACK OF A WEAK SHORTWAVE WEDNESDAY
NIGHT TOWARDS THE NORTHERN PLAINS...WITH EVEN THE SOUTHERNMOST
REFLECTION OF THIS BARELY INFLUENCING SW NEBRASKA. WITH THE PRECIP
SIGNAL SHIFTED NORTH AND A VERY DRY AIR MASS IN PLACE (ON ALL
AVAILABLE GUIDANCE) I REMOVED THUNDERSTORM MENTION FROM WEDNESDAY
NIGHT. BY THURSDAY A STRONGER SHORTWAVE WILL BEGIN TO BREAKDOWN THE
WESTERN PART OF THE RIDGE ALLOWING BETTER FORCING TO MOVE TOWARDS
THE PLAINS...AND WITH AT LEAST MODERATE INSTABILITY AND SHEER IN
PLACE WE COULD START TO SEE THUNDERSTORM INITIATION BY THURSDAY
AFTERNOON IN THE WEST. THE BEST CHANCES WILL HOLD OFF UNTIL THURSDAY
NIGHT WHEN BETTER FORCING WILL BE IN PLACE.
TEMPERATURES SHOULD RETURN TO SEASONAL VALUES IN THE UPPER 80S
TODAY...WITH CONTINUED WARMING THROUGH THURSDAY. THE WARMEST DAY
THIS WEEK WILL LIKELY BE ON THURSDAY WHEN GOOD SOUTHERLY FLOW WILL
SUPPORT TEMPERATURES AT LEAST IN THE MIDDLE 90S. GUIDANCE IS SHOWING
H85 TEMPS AROUND 30C WHICH WITH GOOD MIXING (LITTLE CLOUD COVER) MAY
SUPPORT TEMPS IN THE UPPER 90S/NEAR 100F.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 235 AM MDT TUE AUG 12 2014
NO SIGNIFICANT CHANGES WERE NEEDED IN THE EXTENDED. THE BIGGEST
CHALLENGE WILL CONTINUE TO BE TIMING OF BEST PRECIPITATION CHANCES.
MEDIUM RANGE GUIDANCE SHOWS A WEST/NORTHWESTERLY UPPER FLOW REGIME
WITH PERIODIC SHORTWAVE TROUGHS PASSING THROUGH. ONE WAVE WILL MOVE
EASTWARD THROUGH THE CENTRAL HIGH PLAINS ON FRIDAY BRINGING
SLIGHT/LOW CHANCE POPS TO THE ENTIRE FORECAST AREA. BEYOND
FRIDAY...GFS IS MORE PROGRESSIVE THAN ECMWF AND GFS ENSEMBLE SPREAD
GROWS. GIVEN DIFFERENCES IN THE MODELS TYPICAL OF THIS TYPE PATTERN
WITH TRANSIENT WEAK SHORTWAVES DID NOT TRY TO SEPARATE OUT BEST
CHANCES AND ACCEPTED THE MEDIUM RANGE CONSENSUS BLEND FOR POPS THIS
WEEKEND INTO EARLY NEXT WEEK. TEMPERATURES SHOULD BE SLIGHTLY ABOVE
NORMAL THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 518 AM MDT TUE AUG 12 2014
HIGH PRESSURE AT THE SURFACE AND ALOFT WILL RESULT IN PREVAILING VFR
CONDITIONS AND LIGHT SOUTHEAST WINDS 11 KT OR LESS THROUGH THE TAF
PERIOD AT BOTH KGLD AND KMCK TERMINALS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BRB
AVIATION...DR
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
827 AM EDT TUE AUG 12 2014
.UPDATE...
PLENTY OF LOW LEVEL MOISTURE LEFTOVER ACROSS SOUTHEAST MICHIGAN AS
SURFACE DEW POINTS HOVER IN THE LOW TO MID 60S...AND UPPER LEVEL
TROUGH/COLD POOL (500 MB TEMPS OF -13 TO -14 C) AND SECONDARY
SURFACE COLD FRONT SWINGING THROUGH TODAY WILL BE SUFFICIENT TO
GENERATE NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS...AS THERE
IS ALSO SOLID INSTABILITY WITH SBCAPES IN THE 1000-1500 J/KG
RANGE. 0-6 KM SHEAR REACHES AROUND 20 KNOTS TOWARD THE CANADIAN
BORDER...OTHERWISE SHEAR IS WEAK...AND THUS SEVERE WEATHER IS NOT
EXPECTED. COULD SEE SMALL HAIL AND BRIEF HEAVY RAIN.
&&
.AVIATION...ISSUED 651 AM EDT TUE AUG 12 2014
//DISCUSSION...
A LOWER STRATUS DECK WILL REMAIN PREVALENT THIS MORNING AS ABUNDANT
LOW LEVEL MOISTURE WORKS IN BEHIND A DEPARTING LOW PRESSURE SYSTEM.
THE EXISTING IFR CEILING HEIGHTS ACROSS THE SOUTHERN TAF SITES WILL
LIFT WITH TIME AS DAYTIME HEATING TAKES A STRONGER HOLD. THE
PASSAGE OF A MID LEVEL TROUGH WILL RESULT IN SCATTERED SHOWER AND
THUNDERSTORM DEVELOPMENT DURING THE AFTERNOON AND EARLY EVENING.
CONFIDENCE REMAINS LOW ENOUGH ON POTENTIAL TIMING...COVERAGE AND
DURATION OF THUNDERSTORMS TO PRECLUDE A SPECIFIC MENTION WITH THE
12Z TAF CYCLE. LINGERING MOISTURE WILL FAVOR ADDITIONAL MVFR
STRATUS DEVELOPMENT THROUGH TONIGHT.
FOR DTW...THE MOIST NEAR SURFACE CONDITIONS WILL TAKE SOME TIME TO
MIX OUT...LEAVING IFR CONDITIONS OVER THE AIRSPACE FOR MUCH OF THE
MORNING PERIOD. MVFR/VFR CEILING INTO THE AFTERNOON AS MIXING TAKES
A BETTER HOLD. SCATTERED SHOWERS TODAY...LOW CONFIDENCE IN POSSIBLE
THUNDERSTORM ACTIVITY.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILINGS BELOW 5000 FEET THROUGH TONIGHT.
* LOW CONFIDENCE IN THUNDERSTORM POTENTIAL TODAY.
&&
.PREV DISCUSSION...ISSUED 305 AM EDT TUE AUG 12 2014
SHORT TERM...TODAY AND TONIGHT
HIGH AMPLITUDE MID LEVEL TROUGH NOW SHIFTING ACROSS THE UPPER
MISSISSIPPI VALLEY WILL STEADILY DEEPEN AND EVENTUALLY CLOSE OFF
HEADING INTO TODAY AS IT PIVOTS ACROSS THE LOWER PENINSULA. LEAD
SPOKE OF VORTICITY ANCHORING THE EDGE OF THE MAIN HEIGHT FALL CENTER
CURRENTLY EJECTING ACROSS THE CHICAGO AREA...AND WILL PROVIDE THE
INITIAL WING OF FORCING AS IT TRANSLATES ACROSS MAINLY THE SOUTHERN
HALF OF THE FORECAST AREA EARLY IN THE DAY. THIS MAY PROVE
SUFFICIENT TOWARD SPARKING A FEW SHOWERS...LATEST HI RES GUIDANCE
AND RUC ANALYSIS IN SUPPORT OF A LOW POP MENTION EARLY ON. GREATEST
PROSPECTS FOR PRECIPITATION DEVELOPMENT WILL FOCUS INTO THE
AFTERNOON/EARLY EVENING AS LAPSE RATES STEEPEN CONSIDERABLY THROUGH
BOTH DAYTIME HEATING AND THE PASSAGE OF THE ATTENDANT COLD POOL
/-13C AT 500 MB/. A PERIOD OF GREATER CVA ACCOMPANYING THE MAIN
TROUGH PASSAGE WILL PROVIDE THE BACKGROUND FORCING TO SUPPORT A
SCATTERED COVERAGE OF SHOWERS AND THUNDERSTORMS GIVEN THE
THERMODYNAMIC PROFILE. THE OVERALL TEMPERATURE RECOVERY WILL BE
HINDERED BY LESS FAVORABLE INSOLATION POTENTIAL WITH CLOUD COVER
PROBLEMATIC. HIGHS IN THE LOW AND MIDDLE 70S.
LOW LEVEL COLD AIR ADVECTION TONIGHT AS DEEPER NORTHWEST FLOW
EMERGES ON THE BACKSIDE OF THE EXITING TROUGH. THE BETTER LOW LEVEL
DRYING WILL TAKE MORE TIME TO DEVELOP...NOTING THE SUBSTANTIAL LOW
CLOUD STILL EMANATING ACROSS THE MISSISSIPPI VALLEY THIS MORNING.
THIS POINTS TOWARD SOME LINGERING LOWER STRATUS FOR MUCH OF THE
OVERNIGHT PERIOD...A MORE GRADUALLY CLEARING TREND CLOSER TO
DAYBREAK. LOWS IN THE 50S.
LONG TERM...
TODAY`S SYSTEM WILL PHASE WITH ENERGY DIVING INTO ONTARIO THIS
MORNING TO PRODUCE A LARGE CLOSED LOW CENTERED OVER WESTERN QUEBEC
BY EARLY THURSDAY. AS A RESULT, DRY NORTHWEST FLOW IS FORECAST TO
DOMINATE OVER THE CENTRAL GREAT LAKES FOR THE REMAINDER OF THE WEEK.
WHILE EMBEDDED IMPULSES WITHIN PREVAILING CYCLONIC FLOW ALOFT WILL
PROPAGATE ACROSS THE AREA BOTH WED AND THURS, DEEP MOISTURE WILL
REMAIN WRAPPED AROUND THE OCCLUDING SURFACE LOW. THIS WILL ELIMINATE
CONCERNS FOR PRECIPITATION AND WILL SHIFT THE FOCUS TOWARD CLOUD
COVER EACH DAY. THE LARGEST CHANGE TO THE INHERITED FORECAST WAS TO
BUMP UP AFTN CLOUD COVER BOTH WED AND THURS GIVEN THE PROGGED
FAVORABLE TIMING OF UPPER WAVES WITH PEAK HEATING AND HIGHER
EXPECTATIONS FOR RESIDENT BOUNDARY LAYER MOISTURE GIVEN THE
COMBINATION OF YESTERDAY`S AND TODAY`S RAINFALL.
H85 TEMPS AROUND 10C COMBINED WITH CLOUDS WILL SUPPORT HIGHS IN MOST
PLACES NO BETTER THAN THE MID 70S ON WEDNESDAY. THE AFOREMENTIONED
PASSING UPPER WAVE WILL ORGANIZE A WEAK BAROCLINIC ZONE THAT WILL
PUSH SOUTH THROUGH THE CWA WEDNESDAY NIGHT. WITH H85 TEMPS TAKING
ANOTHER DIVE TO AROUND 6C THURSDAY, HIGHS WILL TOP OUT IN THE LOW
70S, PERHAPS ONLY REACHING THE UPPER 60S THE EASTERN THUMB AND ALONG
THE GLACIAL RIDGE.
EASTWARD PROGRESSION OF THE UPSTREAM UPPER RIDGE WILL FORCE SURFACE
HIGH PRESSURE TO TRANSLATE EASTWARD AND ULTIMATELY SETTLE JUST SOUTH
OF THE AREA ON THURSDAY NIGHT. EASING OF THE LOCAL PRESSURE GRADIENT
WILL RESULT MORE FAVORABLE RADIATING CONDITIONS. AS A RESULT,
DROPPED FORECAST HIGHS SEVERAL DEGREES INTO THE MID 40S OUTSIDE OF
THE METRO AREA. SUSPECT THAT THERE WILL STILL BE ENOUGH BOUNDARY
LAYER MOISTURE HANGING AROUND TO MAKE FOG A CONSIDERATION FOR
THURSDAY NIGHT, BUT WILL REFRAIN FROM INTRODUCING IT INTO THE
FORECAST AT SUCH AN EARLY STAGE. HIGHS WILL REBOUND INTO THE MID 70S
ON FRIDAY IN RESPONSE TO THE DEPARTURE OF THE THERMAL TROUGH.
MARINE...
A FRESH NORTHWEST BREEZE WILL GUST TO NEAR GALES ACROSS THE NORTHERN
HALF OF LAKE HURON LATE THIS AFTERNOON THROUGH THE FIRST HALF OF
TONIGHT AS COLDER AIR FILTERS INTO THE REGION. MARGINAL SMALL CRAFT
ADVISORY CONDITIONS WILL THEREFORE BE POSSIBLE LATE TONIGHT INTO
EARLY WEDNESDAY FOR THE EXPOSED NEARSHORE WATERS OF THE THUMB.
SURFACE HIGH PRESSURE WILL REMAIN UPSTREAM OF THE AREA WHICH WILL
PROMOTE A STEADY STATE MODERATE NORTHWEST FLOW THROUGH THURSDAY
NIGHT. GUSTS IN EXCESS OF 20 KNOTS WILL REMAIN COMMON OVER LAKE
HURON DURING THIS TIME. WINDS WILL EASE A BIT ON FRIDAY AS THE
CENTER OF HIGH PRESSURE SETTLES CLOSER TO THE REGION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......SF
AVIATION.....MR
SHORT TERM...MR
LONG TERM....JVC
MARINE.......JVC
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
651 AM EDT TUE AUG 12 2014
.AVIATION...
//DISCUSSION...
A LOWER STRATUS DECK WILL REMAIN PREVALENT THIS MORNING AS ABUNDANT
LOW LEVEL MOISTURE WORKS IN BEHIND A DEPARTING LOW PRESSURE SYSTEM.
THE EXISTING IFR CEILING HEIGHTS ACROSS THE SOUTHERN TAF SITES WILL
LIFT WITH TIME AS DAYTIME HEATING TAKES A STRONGER HOLD. THE
PASSAGE OF A MID LEVEL TROUGH WILL RESULT IN SCATTERED SHOWER AND
THUNDERSTORM DEVELOPMENT DURING THE AFTERNOON AND EARLY EVENING.
CONFIDENCE REMAINS LOW ENOUGH ON POTENTIAL TIMING...COVERAGE AND
DURATION OF THUNDERSTORMS TO PRECLUDE A SPECIFIC MENTION WITH THE
12Z TAF CYCLE. LINGERING MOISTURE WILL FAVOR ADDITIONAL MVFR
STRATUS DEVELOPMENT THROUGH TONIGHT.
FOR DTW...THE MOIST NEAR SURFACE CONDITIONS WILL TAKE SOME TIME TO
MIX OUT...LEAVING IFR CONDITIONS OVER THE AIRSPACE FOR MUCH OF THE
MORNING PERIOD. MVFR/VFR CEILING INTO THE AFTERNOON AS MIXING TAKES
A BETTER HOLD. SCATTERED SHOWERS TODAY...LOW CONFIDENCE IN POSSIBLE
THUNDERSTORM ACTIVITY.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILINGS BELOW 5000 FEET THROUGH TONIGHT.
* LOW CONFIDENCE IN THUNDERSTORM POTENTIAL TODAY.
&&
.PREV DISCUSSION...ISSUED 305 AM EDT TUE AUG 12 2014
SHORT TERM...TODAY AND TONIGHT
HIGH AMPLITUDE MID LEVEL TROUGH NOW SHIFTING ACROSS THE UPPER
MISSISSIPPI VALLEY WILL STEADILY DEEPEN AND EVENTUALLY CLOSE OFF
HEADING INTO TODAY AS IT PIVOTS ACROSS THE LOWER PENINSULA. LEAD
SPOKE OF VORTICITY ANCHORING THE EDGE OF THE MAIN HEIGHT FALL CENTER
CURRENTLY EJECTING ACROSS THE CHICAGO AREA...AND WILL PROVIDE THE
INITIAL WING OF FORCING AS IT TRANSLATES ACROSS MAINLY THE SOUTHERN
HALF OF THE FORECAST AREA EARLY IN THE DAY. THIS MAY PROVE
SUFFICIENT TOWARD SPARKING A FEW SHOWERS...LATEST HI RES GUIDANCE
AND RUC ANALYSIS IN SUPPORT OF A LOW POP MENTION EARLY ON. GREATEST
PROSPECTS FOR PRECIPITATION DEVELOPMENT WILL FOCUS INTO THE
AFTERNOON/EARLY EVENING AS LAPSE RATES STEEPEN CONSIDERABLY THROUGH
BOTH DAYTIME HEATING AND THE PASSAGE OF THE ATTENDANT COLD POOL
/-13C AT 500 MB/. A PERIOD OF GREATER CVA ACCOMPANYING THE MAIN
TROUGH PASSAGE WILL PROVIDE THE BACKGROUND FORCING TO SUPPORT A
SCATTERED COVERAGE OF SHOWERS AND THUNDERSTORMS GIVEN THE
THERMODYNAMIC PROFILE. THE OVERALL TEMPERATURE RECOVERY WILL BE
HINDERED BY LESS FAVORABLE INSOLATION POTENTIAL WITH CLOUD COVER
PROBLEMATIC. HIGHS IN THE LOW AND MIDDLE 70S.
LOW LEVEL COLD AIR ADVECTION TONIGHT AS DEEPER NORTHWEST FLOW
EMERGES ON THE BACKSIDE OF THE EXITING TROUGH. THE BETTER LOW LEVEL
DRYING WILL TAKE MORE TIME TO DEVELOP...NOTING THE SUBSTANTIAL LOW
CLOUD STILL EMANATING ACROSS THE MISSISSIPPI VALLEY THIS MORNING.
THIS POINTS TOWARD SOME LINGERING LOWER STRATUS FOR MUCH OF THE
OVERNIGHT PERIOD...A MORE GRADUALLY CLEARING TREND CLOSER TO
DAYBREAK. LOWS IN THE 50S.
LONG TERM...
TODAY`S SYSTEM WILL PHASE WITH ENERGY DIVING INTO ONTARIO THIS
MORNING TO PRODUCE A LARGE CLOSED LOW CENTERED OVER WESTERN QUEBEC
BY EARLY THURSDAY. AS A RESULT, DRY NORTHWEST FLOW IS FORECAST TO
DOMINATE OVER THE CENTRAL GREAT LAKES FOR THE REMAINDER OF THE WEEK.
WHILE EMBEDDED IMPULSES WITHIN PREVAILING CYCLONIC FLOW ALOFT WILL
PROPAGATE ACROSS THE AREA BOTH WED AND THURS, DEEP MOISTURE WILL
REMAIN WRAPPED AROUND THE OCCLUDING SURFACE LOW. THIS WILL ELIMINATE
CONCERNS FOR PRECIPITATION AND WILL SHIFT THE FOCUS TOWARD CLOUD
COVER EACH DAY. THE LARGEST CHANGE TO THE INHERITED FORECAST WAS TO
BUMP UP AFTN CLOUD COVER BOTH WED AND THURS GIVEN THE PROGGED
FAVORABLE TIMING OF UPPER WAVES WITH PEAK HEATING AND HIGHER
EXPECTATIONS FOR RESIDENT BOUNDARY LAYER MOISTURE GIVEN THE
COMBINATION OF YESTERDAY`S AND TODAY`S RAINFALL.
H85 TEMPS AROUND 10C COMBINED WITH CLOUDS WILL SUPPORT HIGHS IN MOST
PLACES NO BETTER THAN THE MID 70S ON WEDNESDAY. THE AFOREMENTIONED
PASSING UPPER WAVE WILL ORGANIZE A WEAK BAROCLINIC ZONE THAT WILL
PUSH SOUTH THROUGH THE CWA WEDNESDAY NIGHT. WITH H85 TEMPS TAKING
ANOTHER DIVE TO AROUND 6C THURSDAY, HIGHS WILL TOP OUT IN THE LOW
70S, PERHAPS ONLY REACHING THE UPPER 60S THE EASTERN THUMB AND ALONG
THE GLACIAL RIDGE.
EASTWARD PROGRESSION OF THE UPSTREAM UPPER RIDGE WILL FORCE SURFACE
HIGH PRESSURE TO TRANSLATE EASTWARD AND ULTIMATELY SETTLE JUST SOUTH
OF THE AREA ON THURSDAY NIGHT. EASING OF THE LOCAL PRESSURE GRADIENT
WILL RESULT MORE FAVORABLE RADIATING CONDITIONS. AS A RESULT,
DROPPED FORECAST HIGHS SEVERAL DEGREES INTO THE MID 40S OUTSIDE OF
THE METRO AREA. SUSPECT THAT THERE WILL STILL BE ENOUGH BOUNDARY
LAYER MOISTURE HANGING AROUND TO MAKE FOG A CONSIDERATION FOR
THURSDAY NIGHT, BUT WILL REFRAIN FROM INTRODUCING IT INTO THE
FORECAST AT SUCH AN EARLY STAGE. HIGHS WILL REBOUND INTO THE MID 70S
ON FRIDAY IN RESPONSE TO THE DEPARTURE OF THE THERMAL TROUGH.
MARINE...
A FRESH NORTHWEST BREEZE WILL GUST TO NEAR GALES ACROSS THE NORTHERN
HALF OF LAKE HURON LATE THIS AFTERNOON THROUGH THE FIRST HALF OF
TONIGHT AS COLDER AIR FILTERS INTO THE REGION. MARGINAL SMALL CRAFT
ADVISORY CONDITIONS WILL THEREFORE BE POSSIBLE LATE TONIGHT INTO
EARLY WEDNESDAY FOR THE EXPOSED NEARSHORE WATERS OF THE THUMB.
SURFACE HIGH PRESSURE WILL REMAIN UPSTREAM OF THE AREA WHICH WILL
PROMOTE A STEADY STATE MODERATE NORTHWEST FLOW THROUGH THURSDAY
NIGHT. GUSTS IN EXCESS OF 20 KNOTS WILL REMAIN COMMON OVER LAKE
HURON DURING THIS TIME. WINDS WILL EASE A BIT ON FRIDAY AS THE
CENTER OF HIGH PRESSURE SETTLES CLOSER TO THE REGION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....MR
SHORT TERM...MR
LONG TERM....JVC
MARINE.......JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1049 AM EDT TUE AUG 12 2014
.SYNOPSIS...
A DEEPENING AREA OF LOW PRESSURE WILL MOVE FROM SOUTHERN LAKE HURON
NORTH ACROSS ONTARIO AND DRAG SEVERAL FRONTAL BOUNDARIES ACROSS
WESTERN AND CENTRAL NEW YORK WHICH WILL PRODUCE SEVERAL ROUNDS OF
SHOWERS AND SCATTERED THUNDERSTORMS. BEHIND THIS SYSTEM...EXPECT A
COUPLE OF DAYS OF UNSETTLED AND COOL WEATHER.
&&
.NEAR TERM /THROUGH TONIGHT/...
RADAR IMAGERY LATE THIS MORNING SHOWING THE STEADIER SHOWERS
SHIFTING INTO CENTRAL NY WITHIN A REGION OF STRONGER LOW LEVEL
CONVERGENCE ALONG A SLOW MOVING WARM FRONTAL BOUNDARY SUPPORTED BY A
40+ KNOT LOW LEVEL JET. BEHIND THESE STEADIER SHOWERS A FEW MORE
WIDELY SCATTERED SHOWERS ARE STILL FOUND ACROSS THE INTERIOR
SOUTHERN TIER AND WESTERN FINGER LAKES. EXPECT THE STEADIER SHOWERS
TO CONTINUE ACROSS CENTRAL NY AND THE NORTH COUNTRY INTO MID
AFTERNOON. ACROSS WESTERN NY...THE BREAK IN THE RAIN ON THE LAKE
PLAINS SHOULD LAST THROUGH EARLY TO MID AFTERNOON BEFORE CONVECTION
BEGINS TO BREAK OUT NEAR PEAK HEATING.
SATELLITE IMAGERY SHOWING A FEW BINOVC DEVELOPING OVER LAKE ERIE AND
THE NIAGARA FRONTIER. THESE BREAKS SHOULD ALLOW FOR JUST ENOUGH
SURFACE HEATING TO YIELD SBCAPE OF 1000-1500J/KG BY MID TO LATE
AFTERNOON WITH CONTRIBUTION TO DESTABILIZATION FROM MID LEVEL HEIGHT
FALLS AND COOLING WITH THE APPROACH OF A STRONG MID LEVEL TROUGH.
INCREASING ASCENT IN THE DPVA REGION AHEAD OF THIS TROUGH COMBINED
WITH LOW LEVEL CONVERGENCE ALONG A SURFACE COLD FRONT AND
DIFFERENTIAL HEATING BOUNDARIES SHOULD SUPPORT A BROKEN BAND OF
CONVECTION BY LATE AFTERNOON ACROSS FAR WESTERN NY...WITH SUPPORT OF
THIS FROM MESOSCALE MODEL GUIDANCE SUCH AS THE HRRR AND THE SSEO.
DEEP LAYER 0-6KM SHEAR OF AROUND 40 KNOTS COMBINED WITH MODEST BUT
SUFFICIENT INSTABILITY AND GOOD SYNOPTIC SUPPORT MAY ALLOW
CONVECTION TO GROW UPSCALE INTO ORGANIZED CLUSTERS AND BOWING
SEGMENTS...WITH SOME RISK OF ISOLATED DAMAGING WINDS. SOME OF THE
STRONGER CORES MAY ALSO PRODUCE MARGINAL SEVERE HAIL AND LOCALLY
HEAVY RAINFALL. GREATEST RISK OF SEVERE WILL BE FROM MID AFTERNOON
THROUGH MID EVENING FROM THE GENESEE VALLEY WESTWARD.
THE COLD FRONT CROSSES THE REGION OVERNIGHT JUST REACHING THE
EASTERN BORDER OF THE CWA TOWARD MORNING. THIS COMBINED WITH THE
APPROACH OF THE MID LEVEL TROUGH AXIS AND ASSOCIATED LARGE SCALE
ASCENT WILL KEEP SHOWERS AND A FEW THUNDERSTORMS GOING OVERNIGHT
WITH THE FOCUS FOR MORE ORGANIZED RAIN SHIFTING TO CENTRAL NY.
RAINFALL WISE...MOST AREAS CAN EXPECT TO SEE TOTALS OF ONE TO ONE
AND A HALF INCHES WITH THE GREATEST BASIN AVERAGE AMOUNTS EXPECTED
EAST OF LAKE ONTARIO. GIVEN THE RECENT DRY SPELL THESE AMOUNTS
SHOULD NOT POSE ANY BIG HYDRO CONCERNS. LOCALIZED HEAVIER
THUNDERSTORM RAINS COULD HOWEVER PRODUCE SOME LOCALIZED POOR
DRAINAGE ISSUES.
WINDS WILL INCREASE ACROSS THE EASTERN SECTIONS OF THE CWA LATER
TODAY/TONIGHT. BLACK RIVER VALLEY MAY SEE GUSTS APPROACHING 40 MPH.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
A DEEPENING UPPER LOW WILL MOVE FROM ITS CURRENT POSITION OVER THE
CENTRAL GREAT LAKES TO QUEBEC BY THURSDAY. THE ASSOCIATED SURFACE
COLD FRONT WILL LIKELY BE JUST EAST OF THE FORECAST AREA AS WE OPEN
THE DAY WEDNESDAY...NONETHELESS WITH SUCH STRONG UPPER LEVEL
TROUGHING MOVING OVERHEAD THE REGION...EXPECT SCATTERED SHOWERS TO
LINGER ACROSS THE AREA...PARTICULARLY ACROSS THE NORTH COUTNRY WHERE
A PRONOUNCED UPSLOPE WESTERLY FLOW WILL AID IN ENHANCING SHOWER
CHANCES. THE COMBINATION OF INCREASINGLY COOL AIR ARRIVING ACROSS
THE REGION AND CLOUDINESS ASSOCIATED WITH THE UPPER LEVEL TROUGH
WILL KEEP TEMPERATURES WELL BELOW NORMAL WEDNESDAY WITH HIGHS
RANGING FROM THE MID-60S TO THE LOWER 70S.
SHOWER CHANCES WILL DIMINISH WEDNESDAY NIGHT BETWEEN THE LOSS OF
DIURNAL HEATING AND THE ADVECTION OF DRIER AIR OUT OF THE CANADIAN
ARCTIC ACROSS THE REGION. THAT SAID...WITH SUCH A STRONG TROUGH
HANGING AROUND...CANNOT RULE OUT A STRAY SHOWER OR
TWO...PARTICULARLY ACROSS THE NORTH COUTNRY WHERE WESTERLY UPSLOPE
FLOW. LOOK FOR LOWS IN THE 50S WEDNESDAY NIGHT.
THURSDAY AND THURSDAY NIGHT WILL BE THE COOLEST PARTS OF THE WEEK AS
THE AFOREMENTIONED COLD ADVECTION REACHES ITS PEAK WITH 850MB TEMPS
DROPPING AS LOW AS +5 TO +7C. THIS WILL ONLY SUPPORT HIGHS IN THE
60S ACROSS THE FORECAST AREA WITH LOW TO MID 50S THURSDAY
NIGHT...WHILE PORTIONS OF THE SOUTHERN TIER WILL LIKELY FALL INTO
THE UPPER 40S. THE MITIGATING FACTOR IN KEEPING TEMPERATURES FROM
PLUNGING LOWER THURSDAY NIGHT WILL BE THE PERSISTENT WESTERLY FLOW
AND RESULTING LAKE EFFECT CLOUD COVER. SPEAKING OF LAKE
EFFECT...WITH TEMPERATURES ALOFT COOLING TO +5C...WE MAY SEE MORE
LAKE ENHANCED/UPSLOPE SHOWER ACTIVITY EAST OF LAKE ONTARIO THURSDAY
AND THURSDAY NIGHT WHILE PERSISTENT DRY AIR ALOFT WILL KEEP SHOWERS
LIMITED TO JUST A SLIGHT CHANCE ELSEWHERE.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE UPPER LEVEL LOW WILL DRIFT ACROSS QUEBEC FRIDAY BEFORE
EVENTUALLY LIFTING NORTHEAST INTO LABRADOR THIS WEEKEND. WITHT HE
DEPARTURE OF THE LOW AND ASSOCIATED TROUGHING...TEMPERATURES WILL
RECOVER NICELY BACK INTO THE 70S BY THE WEEKEND AS HIGH PRESSURE
SLIDES BY TO OUR SOUTH.
WHILE FRIDAY NIGHT AND SATURDAY LOOK TO BE DRY FOR MUCH OF THE
FORECAST AREA...CONDITIONS MAY BECOME MORE UNSETTLED FOR THE SECOND
HALF OF THE WEEKEND AND POSSIBLY INTO MONDAY AS ANOTHER SHORTWAVE IS
PROGGED TO DROP ACROSS THE GREAT LAKES. MODEL AGREEMENT ON THE
POSITION/TIMING OF THIS FEATURE IS SHAKY AT BEST AT THIS TIME
HOWEVER...PARTICULARLY AS SOME SOLUTIONS HAVE THIS FEATURE
INTERACTING WITH A CUTOFF LOW DRIFTING OUT OF THE CENTRAL PLAINS
STATES. GIVEN ALL OF THIS UNCERTAINTY...AM KEEPING POPS IN THE
SLIGHT CHANCE RANGE FOR NOW WITH TEMPERATURES TRENDING TOWARDS
CLIMATOLOGY WITH HIGHS IN THE UPPER 70S AND LOWS IN THE UPPER
50S/LOWER 60S.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
A MIX OF VFR AND MVFR CONDITIONS WILL PREVAIL ACROSS THE LOWER
ELEVATIONS FOR MUCH OF THE DAY AS LOW PRESSURE DEEPENS OVER LAKE
HURON AND LIFTS NORTH ACROSS ONTARIO. LINES OF CONVECTION ARE
ANTICIPATED ACROSS THE WEST THIS AFTERNOON IN ADVANCE OF AN
APPROACHING COLD FRONT. SOME OF THE RAIN/THUNDERSTORMS MAY BE HEAVY
WITH CONDITIONS BRIEFLY LOWERING TO IFR. ACROSS THE HIGHER TERRAIN
OF THE SOUTHERN TIER AND FINGER LAKES AREAS OF IFR CIGS WILL
CONTINUE THROUGH MIDDAY BEFORE SLOWLY IMPROVING TO MVFR THIS
AFTERNOON.
OUTLOOK...
WEDNESDAY...VFR WITH A CHANCE OF MVFR IN SHOWERS AND THUNDERSTORMS.
THURSDAY AND FRIDAY...VFR WITH A CHANCE OF MVFR IN SHOWERS.
SATURDAY...VFR.
&&
.MARINE...
UNSETTLED WEATHER WILL MOVE INTO THE LOWER GREAT LAKES REGION AS A
DEEPENING LOW MOVES FROM SOUTHERN LAKE HURON ACROSS ONTARIO AND ONTO
QUEBEC. S-SW WINDS WILL CREATE SMALL CRAFT ADVISORY CONDITIONS ON
ALL NEARSHORE WATERS TODAY. CHOPPY CONDITIONS ARE EXPECTED TO LAST
THROUGH WEDNESDAY. CURRENT SMALL CRAFT ADVISORIES WILL EXPIRE THIS
AFTERNOON. ADDITIONAL SCA MAY BE NEEDED POST COLD-FRONTAL LATER
TONIGHT/WEDNESDAY. COOLER TEMPERATURES ALOFT WILL BE MARGINALLY
FAVORABLE FOR FOR WATERSPOUT FORMATION WEDNESDAY THROUGH THE END OF
THE WEEK.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LEZ020-
040-041.
SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR
LOZ042-043.
SMALL CRAFT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR
LOZ044-045.
&&
$$
SYNOPSIS...HITCHCOCK/LEVAN
NEAR TERM...HITCHCOCK/LEVAN
SHORT TERM...WOOD
LONG TERM...WOOD
AVIATION...LEVAN
MARINE...HITCHCOCK/LEVAN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1040 AM EDT TUE AUG 12 2014
.SYNOPSIS...
LINGERING TROPICAL MOISTURE ACROSS THE CAROLINAS WILL TRIGGER
SCATTERED TORRENTIAL SHOWERS AND THUNDERSTORMS THROUGH EARLY
WEDNESDAY. A COLD FRONT WILL CROSS THE COAST EARLY ON THURSDAY...
BRINGING A DRYING TREND ALONG WITH COOLER OVERNIGHT TEMPERATURES.
SEASONABLE WEATHER FOR MIDDLE AUGUST IS EXPECTED EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM TUESDAY...THIS MORNING`S FORECAST UPDATE FEATURES NO
SIGNIFICANT CHANGES FROM THE PREVIOUS FORECAST. THE STATIONARY FRONT
THAT HAD BEEN STALLED ACROSS SOUTH CAROLINA FOR THE PAST COUPLE OF
DAYS HAS LIFTED NORTHWARD INTO NORTHERN NORTH CAROLINA...ACCOMPANIED
BY A WEAK AREA OF LOW PRESSURE. THIS WILL REMOVE SOME OF THE
LOW-LEVEL FORCING THAT FAVORED WIDESPREAD THUNDERSTORM ACTIVITY OVER
THE PAST FEW DAYS. MORNING LOW STRATUS AND FOG IS BURNING OFF AND
SHOULD HAVE ITS MOISTURE INCORPORATED INTO AN ACTIVE CUMULUS FIELD
THIS AFTERNOON.
THE ATMOSPHERE IS VERY MOIST AND CONDITIONALLY UNSTABLE.
PRECIPITABLE WATER VALUES WERE 2.1 TO 2.2 INCHES ON THE 12Z MHX AND
CHS SOUNDINGS. ASSUMING HIGH TEMPERATURES REACH THE UPPER 80S TO
AROUND 90 LOOK FOR SURFACE-BASED CAPE TO RISE TO NEAR 2000 J/KG WITH
NO CAPPING AND LIFTED INDICES AROUND -5. STEERING FLOW AND SURFACE
WINDS ARE CURRENTLY VERY LIGHT...BUT AS THE DAY PROGRESSES AN
APPROACHING UPPER LEVEL TROUGH AND SURFACE COLD FRONT (NOW ACROSS
THE OHIO VALLEY INTO TENNESSEE) WILL CAUSE AN ACCELERATION OF WINDS
THROUGHOUT THE TROPOSPHERE. THIS WILL NOT APPRECIABLY AFFECT STORM
ORGANIZATION BUT WILL INCREASE STORM MOTION TO 15-20 MPH BY LATE IN
THE DAY. HIGH PRECIPITABLE WATER VALUES PLUS A VERY DEEP WARM CLOUD
LAYER FOR EFFICIENT COALESCENCE-DOMINATED PRECIPITATION PROCESSES TO
OCCUR BOTH ARGUE FOR INCLUSION OF HEAVY RAIN MENTION IN THE FORECAST
AGAIN THIS AFTERNOON INTO EARLY THIS EVENING. THE FREEZING LEVEL IS
FORECAST TO REACH 16KFT THIS AFTERNOON.
RECENT HRRR MODEL RUNS ARE FOCUSED ON TWO AREAS FOR CONVECTIVE
INITIATION LATER TODAY: THE SEABREEZE BOUNDARY ALONG THE COAST...AND
THE SC MIDLANDS/PEE DEE REGION. I HAVE INCREASED POPS TO NEAR 60
PERCENT FOR THE FLORENCE AREA LATE THIS AFTERNOON INTO EARLY THIS
EVENING AS THE BULK OF RECENT MODEL DATA PAINTS THE BEST POTENTIAL
FOR THUNDERSTORMS HERE. FEWER CHANGES WERE NEEDED ELSEWHERE.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 330 AM TUESDAY...THE UPPER LONGWAVE PATTERN THRU THIS PERIOD
WILL EXHIBIT A WELL AMPLIFIED TROF AFFECTING THE UNITED STATES
EAST OF THE MISSISSIPPI RIVER. THIS HAS BEEN PLAYED OUT FOR MUCH
OF THIS SUMMER SEASON. AT THE SFC...THE FA WILL HAVE TO DEAL WITH
A COLD FRONTAL PASSAGE DURING WEDNESDAY...ALTHOUGH MODELS HAVE
BEEN TRENDING WITH SLOWER CFP DURING THE PAST FEW RUNS. AS A
RESULT...HAVE INCLUDED CHANCE POPS UP THRU SUNSET WEDNESDAY. THE
DAYS INSOLATION WILL ADD INSTABILITY TO THE LOCAL ATM. A MID-LEVEL
VORT MAX IS PROGGED TO ROUND THE BASE OF THE UPPER LONGWAVE TROF
DURING WED AFTN AND ACROSS THE FA...FURTHER ADDING DYNAMICS AND
UVVS TO THE MIX. SOME OF THESE STORMS COULD END UP BEING STRONG TO
POSSIBLY SEVERE AS DRIER AIR ALOFT AND INCREASING WIND SPEED SHEAR
THRU THE ATM PROFILE. AGAIN NOT LOOKING AT WIDESPREAD
PCPN...SHOULD BE SCATTERED AT BEST. VARIOUS MODEL MOS GUIDANCE
SIMILAR WITH MAX TEMPS WED...RUNNING ATLEAST A CAT ABOVE CLIMO
NORMS.
FOR WED NIGHT THRU THU NIGHT...THE MEAN UPPER LONGWAVE N-S TROF AXIS
TO RESIDE OVERHEAD OR JUST WEST OF THE ILM CWA. THIS POSITIONING
WILL BE IMPORTANT WITH REGARD TO HOW FAR SOUTH AND EAST THE COLD
FRONT PROGRESSES BEFORE STALLING AS IT BECOMES ORIENTED PARALLEL TO
THE UPPER FLOW. FOR NOW...WILL MAINTAIN ITS FINAL POSITIONING WELL
SOUTH AND EAST OF THE ILM CWA DURING THIS PERIOD. AS A
RESULT...DRIER AIR WILL INFILTRATE THE FA. NOT NECESSARILY
COOLER...DUE TO THE ATM HAVING BEEN UNDER OVERCAST SKIES AND OFF AND
ON PCPN FOR THE PAST 3-4 DAYS. WILL ILLUSTRATE NO POPS FOR WED NITE
THRU THU NITE GIVEN THE SUBSIDENCE PREVAILING ACROSS THE FA. STILL
ENOUGH MOISTURE IN THE LOW LEVELS FOR DIURNALLY DRIVEN CU FOR
DAYLIGHT THU. MAX/MIN TEMPS TO RUN ONE TO 2 CAT BELOW NORMAL.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 330 AM TUESDAY...THE START OF THIS PERIOD...MODELS CONTINUE
WITH A WELL AMPLIFIED LONGWAVE UPPER TROF AFFECTING THE EASTERN
1/3RD OF THE U.S...WHICH INCLUDES THE ILM CWA. THE MEAN N-S UPPER
TROF AXIS TO LIE NEARLY OVERHEAD. THIS IS IMPORTANT BECAUSE THE
STALLED/STATIONARY SFC FRONT WILL REMAIN JUST FAR ENOUGH EAST AND
SOUTH OF THE FA...AND SO DOES THE PCPN ASSOCIATED WITH IT. FOR
FRI...JUST ENOUGH INSTABILITY AND LOW LEVEL MOISTURE AVBL FOR A
LOW CHANCE POP ALONG THE COASTAL COUNTIES FOR ANY SEA BREEZE
INDUCED SHOWERS OR THUNDERSTORMS.
DURING THE UPCOMING WEEKEND...MODEL CONSENSUS IS FOR THIS LONGWAVE
UPPER TROF TO DE-AMPLIFY AND FLATTEN-SOME. LOOK FOR A BETTER CHANCE
FOR DIURNALLY DRIVEN CONVECTION BY SUNDAY AND ESPECIALLY INTO NEXT
WEEK AS THE MOISTURE AND INSTABILITY RETURN. THE SFC PIEDMONT TROF
TO RETURN AND THE DAILY SEA BREEZE WILL PROVIDE THE FORCING TO AID
THE DIURNALLY DRIVEN CONVECTION. HAVE LEANED TOWARD THE GFS SOLUTION
WITH BERMUDA RIDGING TO POSSIBLY AFFECT THE FA AT THE END OF THE
LONG TERM PERIOD.
MAX/MIN TEMPS TO START OUT SLIGHTLY BELOW CLIMO NORMS FRI...THEN
MODERATE TO NEAR OR SLIGHTLY ABOVE NORMAL DURING THE REMAINDER OF
THE LONG TERM PERIOD.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 12Z...DENSE FOG WILL LINGER INLAND WITH PATCHES OF LIFR
STRATUS ALONG THE COAST. LOW PRESSURE WILL REMAIN OVER THE REGION
THROUGH THE AFTERNOON HOURS WITH TROPICAL MOISTURE IN PLACE. SHOULD
SEE A DECENT COVERAGE OF CONVECTION THIS AFTERNOON AS TEMPS RISE
INTO THE MID AND UPPER 80S...WITH THE RESULTANT BOUNDARY A FOCUS FOR
SHOWERS. WILL TWEAK THE TIMING AND COVERAGE OF THE CONVECTION WITH
LATE MORNING UPDATES. WINDS WILL BE MAINLY EASTERLY EARLY...BECOMING
SOUTHERLY IN THE AFTERNOON.
EXTENDED OUTLOOK...ISOLATED TO SCATTERED SHRA/TSRA ALONG WITH TEMPO
MVFR CONDITIONS THROUGH TUESDAY NIGHT. IMPROVING CONDITIONS WED AS A
FRONT MOVES OFFSHORE. VFR THURS THROUGH SAT.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM TUESDAY...WEAK LOW PRESSURE ALONG A FRONT THAT HAD
BEEN STALLED ACROSS SOUTH CAROLINA FOR THE PAST COUPLE OF DAYS IS ON
THE MOVE. ACCORDING TO LATEST WIND DATA THE FRONT ALREADY HAS PUSHED
AS FAR NORTH AS HATTERAS ISLAND. THIS LEAVES A LIGHT SOUTHWESTERLY
WIND ACROSS OUR PORTION OF THE CAROLINAS. INCREASING WIND SPEEDS ARE
EXPECTED THIS AFTERNOON NEARSHORE AS A WEAK TO MODERATE SEABREEZE
CIRCULATION DEVELOPS. WINDS AT THE BEACHES SHOULD INCREASE TO NEAR
12 KNOTS.
A COLD FRONT WILL APPROACH FROM THE WEST LATE TONIGHT. ACCELERATING
WINDS AHEAD OF THIS FEATURE SHOULD PUSH WIND SPEEDS CLOSER TO 15
KNOTS OVERNIGHT...ESPECIALLY AWAY FROM SHORE. SEAS CURRENTLY 2-3
FEET WILL BUILD TO 3-4 FT OVERNIGHT...ESPECIALLY AWAY FROM SHORE.
RADAR AND SATELLITE SHOW CLEAR CONDITIONS ACROSS THE WATERS
CURRENTLY. SCATTERED THUNDERSTORMS SHOULD DEVELOP THIS AFTERNOON
ALONG THE SEABREEZE BOUNDARY JUST INLAND FROM THE COAST. ATMOSPHERIC
STEERING FLOW IS FROM THE WEST WHICH WILL TRY TO PUSH THESE STORMS
ACROSS THE SEABREEZE FRONT INTO THE OCEAN. BETTER CHANCES MAY
DEVELOP THIS EVENING AS A LARGE CLUSTER OF STORMS EXPECTED TO
DEVELOP ACROSS SOUTH CAROLINA THIS AFTERNOON RUNS EAST TOWARD THE
COAST.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM TUESDAY...AHEAD OF THE COLD FRONT DURING
WEDNESDAY...LOOK FOR A TIGHTENED SFC PG AND A PATTERN THAT YIELDS
SW TO WSW WINDS AROUND 15 KT...OCCASIONALLY UP TO 20 KT. THE CFP
IS SLATED FOR WED AFTN AND EVENING. WILL BE LOOKING AT WINDS
VEERING TO THE NW-NE WED NITE THRU THU WITH SPEEDS AROUND 15 KT
THEN DIMINISHING THU AFTN AND NIGHT AS THE COLD FRONT STALLS TO
THE SOUTH AND THE SFC PG RELAXES. MODELS INDICATE RATHER BROAD
HIGH PRESSURE TO RIDGE IN FROM THE NW WITH WIND DIRECTIONS
BECOMING SOMEWHAT VARIABLE IN DIRECTION BY THU NIGHT. SIGNIFICANT
SEAS WILL PEAK IN THE 3 TO POSSIBLY 5 FOOT RANGE DURING WEDNESDAY
INTO WED EVENING AND MAINLY BE A FUNCTION OF LOCALLY PRODUCED 4 TO
6 SECOND PERIOD WIND DRIVEN WAVES. AFTER THE NE-E SURGE WED NITE
INTO THU...PREDOMINATE WIND DRIVEN SIGNIFICANT SEAS WILL BE ON THE
DECLINE. EVENTUALLY... THE ESE 1-2 FOOT GROUND SWELL WILL BECOME
THE DOMINANT SIG. SEAS DRIVER BY LATE THU NIGHT.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 330 AM TUESDAY...A SOMEWHAT RELAXED SFC PG AND A
DISORGANIZED PRESSURE PATTERN VIA LATEST MODEL RUNS INDICATE THAT
MESOSCALE PROCESSES WILL LIKELY CONTROL WINDS FRI INTO SAT. LOOK
FOR AN ACTIVE SEA BREEZE CIRCULATION BOTH DAYS. OVERALL...WINDS
WILL RUN SE-SSW AROUND 10 KT...10-15 KT NEARSHORE DURING THE DAILY
SEA BREEZE. SIGNIFICANT SEAS VIA WAVEWATCH3 AND LOCALLY PRODUCED
SWAN WILL HOVER AROUND 2 FT AND MAINLY BE A FUNCTION OF AN ESE-SE
1-2 FOOT GROUND SWELL. SIG. SEAS COULD POSSIBLY REACH 3 FT
NEARSHORE DUE TO AN INFLUX OF SHORT PERIOD WIND DRIVEN WAVES
DURING THE HEIGHT OF THE AFTN/EARLY EVNG SEA BREEZE CIRCULATION.
&&
.TIDES/COASTAL FLOODING...
AS OF 6 AM TUESDAY...STRONG ASTRONOMICAL TIDES WITH THIS WANING
FULL MOON CYCLE WILL REQUIRE ANOTHER COASTAL FLOOD ADVISORY WITH
TONIGHTS HIGH TIDE FOR THE LOWER CAPE FEAR RIVER SIMILAR TO THE
LAST 3 EVENINGS...BUT LIKELY A FEW INCHES LOWER ON THE PEAK WATER
LEVELS. ELEVATED LEVELS WILL BE OBSERVED ALONG THE BANKS OF THE
ICW AS WELL DURING HIGH TIDE LATE TONIGHT. THE LOWER CAPE FEAR
RIVER WILL EXPERIENCE MINOR COASTAL FLOODING INCLUDING LOCALIZED
AREAS OF DOWNTOWN WILMINGTON. NO COASTAL FLOOD ADVISORIES FOR THE
BEACHES EXPECTED AS ASTRONOMICAL PULLS HAVE ABATED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY FROM 11 PM THIS EVENING TO 2 AM EDT
WEDNESDAY FOR NCZ107.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...DCH
LONG TERM...DCH
AVIATION...DL
TIDES/COASTAL FLOODING...8
AREA FORECAST DISCUSSION
NWS RALEIGH NC
725 AM EDT TUE AUG 12 2014
.SYNOPSIS...A WARM FRONT WILL LIFT NORTH THROUGH THE AREA THIS
MORNING. A COLD FRONT WILL CROSS THE AREA TONIGHT AND EARLY
WEDNESDAY MORNING...FOLLOWED BY HIGH PRESSURE AND DRIER WEATHER FOR
THE BALANCE OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM TUESDAY...
A FEW PATCHES OF LIGHT RAIN ARE CURRENTLY MOVING NORTHEAST THROUGH
THE PIEDMONT...THOUGH THE COVERAGE HAS DECREASED SIGNIFICANTLY SINCE
MIDNIGHT. HIGH PRESSURE OFF THE NEW ENGLAND COAST CONTINUES TO LOSE
ITS INFLUENCE...THOUGH A WEAK LOW OFF THE WILMINGTON COAST IS
HELPING TO MAINTAIN A MORE EASTERLY FLOW OVER CENTRAL NC. RAP
ISENTROPIC ANALYSIS SHOWS THE DEEPER ISENTROPIC LIFT MOVING NORTH
INTO VA...WITH SHALLOW SOUTHEASTERLY FLOW AND UPSLOPE FLOW DRIVING
THE SHOWERS OVER WESTERN NC. RAP VORT FIELDS AND WATER VAPOR
IMAGERY SUGGEST THERE MAY BE A WEAK DISTURBANCE OVER NORTHERN
GEORGIA/UPSTATE SC THAT MAY BE AIDING THESE SHOWERS. THE BULK OF
THIS PRECIP SHOULD STAY JUST TO THE WEST OF THE YADKIN RIVER THROUGH
SUNRISE...BUT SOME LIGHT RAIN WILL LIKELY KEEP THE LINGERING CAD
AIRMASS IN PLACE DESPITE THE LACK OF A STRONG STABLE LAYER OVER THE
WESTERN PIEDMONT...PER 00Z KGSO AND RAP SOUNDINGS.
MEANWHILE...THE FRONTAL ZONE WILL MOVE NORTH THROUGH THE AREA THIS
MORNING....ESPECIALLY AS MIXING INCREASES AND SOME PARTIAL BREAKS IN
CLOUD COVER DEVELOP OVER THE COASTAL PLAIN. AS TEMPS RISE INTO THE
MID TO UPPER 80S...DEWPOINTS IN THE LOWER 70S AND PW AROUND 2 INCHES
WILL LEAD TO MLCAPE OF AT LEAST 1000-1500 J/KG EAST OF THE TRIAD.
THE DEGREE OF DESTABILIZATION IF A LITTLE MORE UNCERTAIN OVER THE
NORTHWEST PIEDMONT...BUT EVEN HIGHER RES GUIDANCE SHOWS THE TRIAD
MIXING OUT BY AROUND NOON. DEEP LAYER SHEAR ISNT OVERLY IMPRESSIVE
WELL OUT AHEAD OF THE UPPER TROUGH AND ASSOCIATED COLD FRONT...WITH
AROUND 25-30KT OVER WESTERN NC...WHICH MAY BE DISPLACED FROM THE
STRONGEST INSTABILITY. THUS...WITH MAINLY CONFLUENT PRE-FRONTAL
FLOW AS THE FORCING THIS AFTERNOON ...THE COVERAGE OF STRONGER
STORMS IS STILL A LITTLE UNCERTAIN. HEAVY RAIN...EXACERBATED BY
RECENT RAINFALL OF 3-5 INCHES IN SOME AREAS...AND STRONG WIND GUSTS
WILL BE THE MAIN THREAT FROM ANY STRONGER CLUSTERS OF STORMS.
AFTERNOON HIGHS SHOULD RANGE FROM THE LOWER 80S NORTHWEST TO UPPER
80S SOUTHEAST.
THE UPPER TROUGH AND ASSOCIATED MODEST HEIGHT FALLS (FOR AUGUST) AND
DCVA WILL ENCROACH ON THE AREA LATE THIS EVENING AND
OVERNIGHT...WITH HE ATTENDANT COLD FRONT PROGGED TO CROSS THE AREA
AFTER MIDNIGHT. FORECAST SOUNDINGS SHOW SOME INSTABILITY OVERNIGHT
AHEAD OF THE FRONT...AND GIVEN THE UPPER FORCING...IT IS PLAUSIBLE
THAT THERE COULD BE ANOTHER BAND OF SHOWERS AND ISOLATED THUNDER
STORMS WITH THE COLD FRONT. DUE TO THE DRYING ALOFT...NOT QUITE
CONFIDENT ENOUGH FOR A CHANCE POP OVERNIGHT...BUT WILL SHOW A
SECONDARY SLIGHT CHANCE AREA WITH THE COLD FRONT. OVERNIGHT LOWS
WILL STILL BE MUGGY IN THE UPPER 60S TO LOWER 70S.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 325 AM TUESDAY...
THE COLD FRONT WILL MOVE TOWARD THE COAST WEDNESDAY MORNING...AS
MUCH DRIER AIR OVERSPREADS THE AREA AND PW DROPS BELOW ONE INCH.
FORECAST SOUNDINGS SHOWS A STRENGTHENING SUBSIDENCE INVERSION ALL THE
WAY EAST TO KRWI AND KFAY...SO ANY ADDITIONAL SHOWERS IN THE
VICINITY OF THE FRONT WILL BE CONFINED TO THE COAST. HIGHS WILL
STILL BE IN THE 83-89 RANGE...BUT THE BIGGER CHANGE WILL BE IN
DEWPOINTS AND THEY FALL INTO THE 50S FROM NORTHWEST TO SOUTHEAST
DURING THE AFTERNOON. THIS WILL ALSO LEAD TO COOLER LOWS...60-
65...AS THICKNESSES DIP BELOW 1390M BY THURSDAY MORNING.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 315 AM TUESDAY...
LITTLE CHANGE IN OVERALL FORECAST RATIONALE FROM THE PAST COUPLE OF
DAYS. THROUGH DAY 5...DETERMINISTIC AND ENSEMBLE MEAN MEDIUM RANGE
GUIDANCE SOLUTIONS ARE IN RELATIVELY GOOD AGREEMENT AND ARE
CHARACTERIZED BY A RELATIVELY HIGH AMPLITUDE RIDGE OVER INTERIOR
WESTERN NOAM...FLANKED BY A COUPLE OF SLOWLY ENE-MIGRATING AND
FILLING UPPER LOWS ACROSS THE NW AND NE CORNERS OF THE CONUS. THE
ASSOCIATED ANOMALOUSLY LOW HEIGHTS ALOFT FROM SOUTHEASTERN CANADA TO
THE CAROLINAS WILL RELAX AND PROMOTE GRADUALLY WARMING CONDITIONS
FRI INTO THE WEEKEND. MODEL SPREAD INCREASES FOR DAYS 6-7...MOST
NOTABLY WITH THE HANDLING OF A SHORTWAVE TROUGH FORECAST TO SETTLE
INTO THE MID-UPPER MS VALLEY EARLY NEXT WEEK. DIFFERENCES WITH THE
HANDLING OF THIS FEATURE ARISE SEEMINGLY IN PART DUE TO THE DEGREE
OF DOWNSTREAM RE-DEVELOPMENT OF A NEGATIVE HEIGHT ANOMALY OVER THE
NE CONUS (IF ANY) - WHICH WOULD EFFECTIVELY SLOW THE PROGRESSION OF
THE FLOW AND EMBEDDED SHORTWAVES UPSTREAM. THE 12Z/11TH EC ENSEMBLE
MEAN PROVIDES A REASONABLE COMPROMISE SOLUTION BETWEEN THE 00Z/12TH
DETERMINISTIC ECMWF (OUTLIER) THAT IS MOST AGGRESSIVE WITH THE RE-
DEVELOPMENT OF THE VORTEX OVER THE NE...VERSUS THE PAST COUPLE OF
RUNS OF THE GFS THAT DEPICT NO RE-DEVELOPMENT WHATSOEVER.
THU THROUGH SUN: A LEAD CANADIAN HIGH WILL BUILD SOUTH INTO THE MID
MS VALLEY THU...AND AWAIT UPSTREAM REINFORCEMENT FROM A REINFORCING
COLD FRONT/CANADIAN HIGH FORECAST TO SETTLE SOUTH ACROSS THE OH AND
TN VALLEYS THROUGH FRI. THOUGH MASKED BY WEAK LEESIDE SFC TROUGHING
IN THE LEE OF THE APPALACHIANS...BENEATH CYCLONIC FLOW ALOFT AND
ASSOCIATED LOW-MID LEVEL WESTERLY (DOWNSLOPE) FLOW...THE CENTER OF
THE CANADIAN HIGH WILL BUILD INTO AND ACROSS THE CENTRAL
APPALACHIANS THROUGH SAT. MOISTURE...AT THE SFC AND THROUGH A DEEP
LAYER...WILL CONSEQUENTLY BE LIMITED. IN FACT...THE RELATIVE DRYNESS
WILL BE HIGHLIGHTED BY SFC DEWPOINTS IN THE 50S AND PRECIPITABLE
WATER VALUES AOB ONE INCH ON THU...BOTH OF WHICH ONLY SLOWLY
INCREASE AND RESULT IN PRIMARILY SEA BREEZE AND MOUNTAIN-INDUCED
CONVECTION...THROUGH THE WEEKEND. WILL INTRODUCE A SLIGHT CHANCE OF
A DIURNALLY-DRIVEN AFTERNOON STORM OVER THE SOUTHERN COASTAL PLAIN
TO ACCOUNT FOR SOME SEA-BREEZE CONVECTION/OUTFLOW PROPAGATING AWAY
FROM COASTAL AREAS.
OTHERWISE...H85 TEMPS INITIALLY IN THE 14-16C RANGE...SHOULD SUPPORT
TEMPERATURES PERHAPS NEAR TO SLIGHTLY BELOW NORMAL THROUGH
FRI...WITH WARMING TO AROUND OR SLIGHTLY ABOVE NORMAL VALUES THROUGH
EARLY NEXT WEEK. THE EVOLUTION OF THE AFOREMENTIONED SHORTWAVE
TROUGH SETTLING ACROSS THE MS VALLEY EARLY NEXT WEEK WOULD FOCUS
ABOVE NORMAL PRECIPITATION CHANCES WEST OF THE APPALACHIANS/OVER THE
OH VALLEY THROUGH DAY 7.
&&
.AVIATION /12Z MONDAY THROUGH SATURDAY/...
AS OF 725 AM TUESDAY...
LIFR/IFR STRATUS IS CURRENTLY OBSERVED ACROSS NEARLY ALL OF CENTRAL
NC...EXCEPT FOR THE NORTHERN COASTAL PLAIN...WHERE KRWI REMAINS VFR.
SCATTERING OF THE LOW CLOUDS WILL OCCUR DURING THE MID-MORNING HOURS
AS A WARM FRONT LIFTS THROUGH THE AREA...FIRST AT KFAY AND KRWI BY
14-15Z. STRATUS WILL LIKELY HAND AROUND LONGER AT
KGSO/KINT...POSSIBLY UNTIL AROUND 16-17Z. WITH AT LEAST PARTIAL
CLEARING...HEATING AND DESTABILIZATION WILL SUPPORT SCATTERED
SHOWERS AND STORMS DURING THE AFTERNOON. CONFIDENCE IN TIMING OF
IMPACT AT TERMINALS IS TOO LOW FOR MENTION OF THUNDER IN TAFS...BUT
PROBABILITIES ARE GREATER AT KRDU/KFAY/KRWI. EXPECT AT LEAST MFR
CEILINGS IN THE TRIAD...IF NOT EVENTUALLY VFR EVERYWHERE DURING THE
AFTERNOON.
A COLD FRONT WILL APPROACH FROM THE WEST DURING THE
EVENING...NEARING KGSO AND KINT BY AROUND MIDNIGHT. A FEW
SHOWERS MAY BE POSSIBLE WITH THE FRONT BETWEEN 06Z AND 12Z.
OUTLOOK...ONCE THE COLD FRONT CLEARS THE AREA WEDNESDAY
MORNING...VFR CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...BLS
SHORT TERM...BLS
LONG TERM...MWS
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
926 AM EDT TUE AUG 12 2014
.SYNOPSIS...
A COLD FRONT AND UPPER LEVEL TROUGH WILL CROSS THE REGION TODAY.
HIGH PRESSURE WILL BUILD IN THE UPPER MIDWEST ON WEDNESDAY AND THEN
SETTLE OVER THE OHIO VALLEY THURSDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COLD FRONT IS PUSHING EAST ACROSS WESTERN OHIO THIS MORNING AND A
NARROW LINE OF SHOWERS AND THUNDERSTORMS HAS DEVELOPED JUST AHEAD
OF IT ACROSS CENTRAL OHIO. AS WE PROGRESS INTO THIS AFTERNOON...THE
BETTER INSTABILITY AND SHEAR WILL BE JUST OFF TO OUR EAST. THE
LATEST HRRR SEEMS TO HAVE A GOOD HANDLE ON THE CURRENT SITUATION...WITH
THE CURRENT LINE OF STORMS INTENSIFYING AS IT PUSHES EAST OF OUR
AREA INTO THE MORE FAVORABLE AIRMASS LATER THIS MORNING INTO
EARLY AFTERNOON. MEANWHILE...EXPECT SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS TO SPREAD BACK IN FROM THE NORTHWEST
THROUGH THE AFTERNOON HOURS AS THE UPPER LEVEL TROUGH AXIS PIVOTS
INTO THE AREA. THIS WILL LIKELY BE DIURNALLY ENHANCED SO EXPECT
HIGHEST POPS WITH THIS ACROSS OUR NORTHWEST...DECREASING OFF TO
THE SOUTHEAST THROUGH LATE AFTERNOON/EARLY EVENING AS WE START TO
LOSE THE DAYTIME HEATING. EXPECT HIGHS TODAY RANGING FROM THE LOW
TO MID 70S ACROSS THE NORTHWEST TO THE UPPER 70S/NEAR 80 IN THE
FAR SOUTHEAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
ANY SEMBLANCE OF SHOWERS SHOULD BE WELL EAST OF THE CWA BY
NIGHTFALL. WNW WINDS AT THE SURFACE WITH HIGH PRESSURE BUILDING IN
THE MIDWEST WILL HELP DRIER AIR TO BE PULLED INTO THE OHIO VALLEY.
NAM AND CANADIAN MODEL ARE SHOWING A POSSIBILITY OF A SPRINKLE
OVER THE REGION IN THE PREDAWN HOURS WED MORNING. IF THIS WERE TO
OCCUR...IT IS PURELY FROM THE COLD POOL OF AIR ALOFT. ATTM...I DO
NOT SEE ENOUGH MOISTURE TO ALLOW THE COLD POOL TO WRING OUT A
SHOWER AND HAVE LEFT THE FORECAST DRY.
ON WEDNESDAY...NORTHWEST WINDS WILL KEEP THE COLD AIR OVER THE
REGION WITH HIGHS STAYING IN THE LOW TO MID 70S. A WEAK BOUNDARY
WILL LINGER NORTH OF KY AND THE REAL COLD PUSH ON NORTHERLY WINDS
WILL POSSIBLY SQUEEZE OUT A SHOWER WNW TO ESE OF METRO CINCY ON
THURSDAY AFTERNOON...SLOWLY PUSHING SOUTH INTO KY BY EVENING. THE
CENTER OF THE HIGH WILL SETTLE OVER THE CWA BY FRIDAY MORNING AND
LOWS THURSDAY NIGHT WILL DROP DOWN INTO THE LOWER 50S ACROSS THE
AREA.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
NORTHWEST FLOW ALOFT AT THE BEGINNING OF THE PERIOD WILL FLATTEN AND
BECOME MORE ZONAL OVER THE WEEKEND. 12Z MODELS ARE IN REASONABLE
AGREEMENT THAT A SHORT WAVE WILL PUSH INTO THE REGION ON MONDAY. AT
THE SURFACE HIGH PRESSURE WILL DOMINATE LATE IN THE WEEK BEFORE
SLIDING OFF TO THE SOUTHEAST DURING THE WEEKEND. CANNOT COMPLETELY
RULE OUT SOME STORMS ACROSS THE NORTHERN COUNTIES OVER THE WEEKEND
ON THE SOUTHERN FRINGE OF A MORE ACTIVE CONVECTIVE CORRIDOR ACROSS
THE GREAT LAKES. BUT BETTER CHANCE OF SHOWERS AND THUNDERSTORMS ARE
EXPECTED ON MONDAY. TEMPERATURES EARLY IN THE PERIOD WILL BE BELOW
NORMAL BUT THEN WARM TO ABOVE NORMAL EARLY NEXT WEEK.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
IFR STRATUS DEVELOPED ACROSS THE ERN TAFS THIS MORNING...ALONG
WITH MVFR FOG AT MOST LOCATIONS. NOW A SFC TROF THAT SHIFTS THE
WINDS TO THE W IS PUSHING THRU INDIANA. AHEAD OF THIS TROF...AN AREA
OF AC IS DEVELOPING...BUT THEN ADDITIONAL MVFR STRATUS HAS DEVELOP
ACROSS INDIANA.
MEANWHILE A VIGOROUS H5 S/W WILL DIG INTO THE REGION THIS
AFTN...PROVIDING LIFT FOR CONVECTION. EXPECT THE STRATUS TO AFFECT
THE REGION THRU 14-15Z...THEN THE AIRMASS WILL
DESTABILIZE....ESPECIALLY OVER THE ERN TAFS. CONVECTION ALLOWING
MODELS DEVELOP PCPN ACROSS THE ERN TAFS LATE THIS MORNING...BUT
LEAVE THE W DRY. FOLLOWED THIS SCENARIO BY PUTTING VCTS IN THE
ERN TAFS FROM 15-18Z. AS THE UPPER TROF APPROACHES THIS AFTN A FEW
SHRA COULD AFFECT THE WRN TAFS IN THE AFTN.
THE H5 TROF S/W WILL WORK E AFT 00Z. THIS SHOULD BRING AN END TO
THE SHOWER/THUNDERSTORM THREAT. MVFR STRATUS COULD REDEVELOP AFT
06Z TONIGHT.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...JGL
SHORT TERM...FRANKS
LONG TERM...
AVIATION...SITES
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
619 AM EDT TUE AUG 12 2014
.SYNOPSIS...
LOW PRESSURE WILL MOVE NORTHEAST THROUGH THE CENTRAL GREAT LAKES
TODAY AND FORCE A COLD FRONT EAST ACROSS THE REGION. A TROUGH OF LOW
PRESSURE WILL EXTEND BACK SOUTHWEST FROM THE LOW PRESSURE ACROSS THE
LOCAL AREA BY WEDNESDAY EVENING. HIGH PRESSURE WILL MOVE EAST AND BE
OVER OHIO BY FRIDAY MORNING AND TO THE MID ATLANTIC COAST BY
SATURDAY MORNING.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
OCCLUDED FRONT WAS OVER EASTERN OHIO WITH THE POINT OF OCCLUSION
OVER SOUTHEAST OHIO. BACK TO THE WEST...COLD FRONT WAS OVER
EASTERN INDIANA FOLLOWED BY A SURFACE TROUGH OVER SOUTHERN LAKE MICHIGAN.
SHOWERS CONTINUE TO PUSH EAST AHEAD OF THE OCCLUDED FRONT AT THIS
TIME AND WILL BE OUT OF THE AREA SOON. ANOTHER SMALL LINE OF
SHOWERS CONTINUES TO DEVELOP ALONG THE COLD FRONT TO THE WEST AND
WILL SPREAD EAST INTO THE FORECAST AREA TODAY.
GRIDS LOOK REASONABLE AND WILL ONLY ADJUST HOURLY DATA FOR TEMPERATURES.
PREVIOUS DISCUSSION...
UPPER LEVEL TROUGH WILL CONTINUE TO DIG SOUTH
INTO THE FORECAST AREA TODAY. THE SURFACE LOW PRESSURE WILL MOVE
NORTH SLIGHTLY ALLOWING A COLD FRONT TO SLIDE EAST ACROSS THE
FORECAST AREA. DEEP MOISTURE WE EXPERIENCED OVER THE LAST 24 HOURS
HAS SINCE MOVED EAST OF THE REGION. AS COLD FRONT MOVES EAST INTO
THE AREA...SOME SHOWER AND THUNDERSTORM ACTIVITY WILL LIKELY
DEVELOP WITH THE FRONT. STILL EXPECTING SOME SUN AHEAD OF THE
FRONTAL BOUNDARY AND THIS WILL HELP DESTABILIZE THE
ATMOSPHERE...ESPECIALLY IN THE EAST. SPC HAS A SLIGHT RISK FOR
SEVERE THUNDERSTORMS IN THE EAST AT THIS TIME.
TEMPERATURES WILL ONCE AGAIN BE TRICKY DO TO TIMING OF THE COLD
FRONT. RIGHT NOW...MODELS ARE IN FAIRLY GOOD AGREEMENT WITH COLD
FRONT PUSHING INTO TOLEDO AND FINDLAY AROUND NOON AND THEN THROUGH
ERIE BY 8 PM THIS EVENING. THE MORE SUN WE GET THE HIGHER THE
TEMPERATURES. AS MENTIONED...BATTLING THE TIMING OF THE FRONT AS
WELL. BUMPED UP MAX TEMPERATURES A FEW DEGREES FOR TODAY TO ACCOUNT
FOR THE SUN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
UPPER LEVEL TROUGH STALLS OVER THE NORTHEASTERN UNITED STATES WHILE
IT EVENTUALLY MORPHS INTO A LARGE UPPER LEVEL LOW PRESSURE SYSTEM BY
THURSDAY NIGHT. THIS IS IN RESPONSE TO A PIECE OF ENERGY PLOWING
INTO THE WESTERN UNITED STATES. AN UPPER LEVEL RIDGE OVER THE WEST
CENTRAL UNITED STATES WILL DEAMPLIFY WITH TIME AND WASH OUT BY
FRIDAY NIGHT.
SURFACE LOW PRESSURE WILL CONTINUE TO PULL OUT TO THE NORTHEAST WITH
TIME AND DRAG THE COLD FRONT EAST AND WELL OUT OF THE REGION TONIGHT
AND WEDNESDAY. A TROUGH OF LOW PRESSURE WILL SETTLE IN OVER THE
REGION WEDNESDAY NIGHT AND THEN LIFT OUT AS WELL.
LARGE AREA OF HIGH PRESSURE IS PROGGED TO BUILD EAST SOUTHEAST INTO
THE FORECAST AREA AND BRING A RETURN BACK TO FAIR WEATHER INTO THE
WEEKEND. THE HIGH EVENTUALLY SHIFTS TO THE MID ATLANTIC COAST
BRINGING A RETURN SOUTHERLY FLOW BACK TO THE REGION.
COLD AIR ADVECTION IN THE WAKE OF THE COLD FRONT WILL TAKE PLACE AND
THEN WE SHOULD SEE A GRADUAL WARM UP BY THE LATTER PORTION OF THE
FORECAST PERIOD.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
THE FORECAST IS BEGINNING TO CHANGE WITH BOTH THE GFS AND ECMWF
BRINGING IN A LOW AND FRONT FOR THE WEEKEND. INTRODUCED 20 POPS FOR
SATURDAY NIGHT AND 30 POPS ON SUNDAY AND THEN ANOTHER WEATHER SYSTEM
WILL BE MOVING IN FOR EARLY NEXT WEEK. TEMPERATURES WILL GO BACK
ABOVE NORMAL EARLY NEXT WEEK.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
A BATCH OF SHOWERS AND THUNDERSTORMS WILL BE EAST OF THE FORECAST
AREA BY 4 AM. SKIES ARE CLEARING FROM THE WEST. WITH PLENTY OF
RAIN EXPECTING FOG AND STRATUS TO DEVELOP. A COLD FRONT WILL BE
MOVING THROUGH DURING THE AFTERNOON. GOING WITH THE HRRR FOR THE
DEVELOPMENT OF THE SQUALL LINE WITH THE FRONT AND SOME SHOWERS
BEHIND IT WITH A TROF. CONDITIONS WILL BEGIN TO IMPROVE FROM THE
WEST AFTER DARK.
OUTLOOK...NON VFR CEILINGS AND VISIBILITY IN PRECIPITATION LINGERING
LATE TUESDAY NIGHT/WEDNESDAY ACROSS NE OH/NW PA.
&&
.MARINE...
CONTINUING THE SMALL CRAFT ADVISORY ON THE EAST END OF THE LAKE
THROUGH 10 AM BECAUSE OF 15 TO 25 KNOT WINDS FROM THE SOUTH. A COLD
FRONT WILL BE CROSSING THE LAKE TODAY. SOME OF THE THUNDERSTORMS MAY
PROMPT THE NEED FOR A SPECIAL MARINE WARNING...ESPECIALLY LATER
TODAY AND ESPECIALLY ON THE EAST END. THE WINDS WILL SLOWLY PICK UP
TONIGHT THROUGH THURSDAY IN THE COLD ADVECTION. A SMALL CRAFT
ADVISORY MAY BE NEEDED. THIS IS NOT A REAL COLD OUTBREAK AND THE
AIR MASS DRIES OUT QUICKLY. BECAUSE OF THAT WILL NOT MENTION
WATERSPOUTS ON WEDNESDAY...BUT THIS WILL HAVE TO BE WATCHED.
HIGH PRESSURE WILL BEGIN BUILDING IN ON THURSDAY AND WILL MOVE EAST
OF THE LAKE ON SATURDAY AS ANOTHER WEATHER SYSTEM APPROACHES. NOT
EXCEPTING CONDITIONS TO MEET SMALL CRAFT ADVISORY CRITERIA FRIDAY
THROUGH SATURDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR LEZ148-
149.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1050 AM EDT TUE AUG 12 2014
.SYNOPSIS...
A STRONG FRONTAL SYSTEM WILL CROSS THE AREA TODAY AND TONIGHT.
GENERALLY DRIER AND COOLER CONDITIONS CAN BE EXPECTED FOR THE
SECOND HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030AM UPDATE...
RAIN FLYING ALONG TO THE EAST/NORTH. A LTG STRIKE OR TWO BUT
ALMOST NONE AT ALL. RAIN RATES BRIEFLY INTENSE...BUT SPEED OF
MOVEMENT AND SIZE OF SHOWERS LIMITING THE ACCUMS. STRIPE OF 2 INCH
RAIN IN CLEARFIELD CO...BUT ELSEWHERE RAIN LESS THAN A HALF OF AN
INCH. LOW OVER VA/NC IS SLIDING NORTH SLIGHTLY AND WILL MOST
LIKELY SLOW THE PROGRESS OF THE MAIN AREA OF SHOWERS THIS AFTN AS
IT TRIES TO GET OUT OF THE CWA. THUS...MOD RAIN STILL EXPECTED
THERE THROUGH THE REST OF THE DAY AND FOR MOST OF THE NIGHT. A BIG
BREAK IN PRECIP WITH ONLY WIDELY SCT SHRA SHOULD OCCUR OVER THE
WESTERN HALF OF THE AREA UNTIL...
MAIN CONCERN SHIFTS TO THE WEST WITH DIURNAL AND FRONTALLY-FORCED
CONVECTION MOVES IN FROM OH/WRN PA. LINE OF STRONG STORMS OVER
CENTRAL OH IS TIMED INTO OUR WRN COS AROUND 19Z. HOLES IN THE
CLOUDS AND THE FRONTAL LIFT MAKING IT EASY TO HAVE THOSE START UP
TO OUR WEST...BUT CLOUDS SHOULD STAY FAIRLY THICK IN THE CENTRAL
AND EASTERN ZONES. SPC SLIGHT RISK CONTINUES FOR ALL OF THE AREA.
WRN PA STORMS MAY PRODUCE WIND DAMAGE. SRN PA COULD ALSO HAVE
SOME SPINNING STORMS DUE TO THE BOUNDARY ALONG OUR SRN COS OR
BORDER. THIS WILL LEAD TO MORE SHEAR AND THE LCL HEIGHTS SHOULD BE
FAIRLY BUT NOT OVERLY LOW. WILL JUST ADD MENTION OF GUSTY WINDS TO
THE THUNDER IN THE WEST LATE THIS AFTN/EVENING.
PREV...
AN ACTIVE DAY IS IN STORE AS A STRONG UPPER TROUGH AND
ACCOMPANYING FRONTAL SYSTEM ENTERS THE REGION. BIGGEST ISSUES
TODAY WILL BE THE POTENTIAL FOR LOCALLY HEAVY RAINS AND
POSSIBILITY OF SEVERE THUNDERSTORMS.
ONCE AGAIN THIS SUMMER WE ARE DEALING WITH A WEATHER SYSTEM
BRINGING UNSEASONABLY STRONG DYNAMICS TO THE FORECAST AREA.
ENSEMBLES AND OPERATIONAL GUIDANCE ALL SHOW A 40-55KT...4-6 STD
DEV...LOW LEVEL SOUTH-SOUTHEASTERLY JET SURGING INTO THE REGION.
THIS HELPS PUSH PWATS IN THE 1.5-2.0 INCH RANGE OVER THE ENTIRE
FCST AREA DURING THE DAY.
THE SETUP SEEMS IS PRIMED FOR A WIDESPREAD MODERATE TO HEAVY RAIN
OVER THE NEXT 12-18 HOURS. HAVE DISCUSSED A POSSIBLE FLOOD WATCH
WITH NEIGHBORING OFFICES AND CONSENSUS IS TO LEAN AWAY FOR THE
TIME BEING GIVEN THE EXPECTED QPF AVERAGING 1-2" AND RECENT
PERIOD OF DRY WEATHER. THE BEST CHANCE FOR DEVELOPING FLOODING
ISSUES SEEMS TO BE ALONG SOME OF THE SMALLER CREEKS AND STREAMS
AND WILL BE HANDLED WITH SHORT TERM ADVISORY/FLOOD PRODUCTS. THE
BEST CHANCE OF THIS WOULD SEEM TO BE OVER ABOUT THE EASTERN HALF
OF MY FCST AREA.
ANOTHER CONCERN IS THAT WHEN THE OCCLUSION/WARM FRONT ENTERS THE
AREA...MARGINAL INSTABILITY AND STRONG SHEAR COULD RESULT IN
SOME LOCALLY SEVERE THUNDERSTORMS WITH AN ISOLATED TORNADO NOT OUT
OF THE QUESTION. RAP AND GFS SHOW A BULLSEYE OF STRONG LOW LEVEL
HELICITY OVER SOUTH CENTRAL PA...IN THE VICINITY OF THE WARM
FRONT THAT WILL BE SLOWLY MOVING NORTH THROUGH EARLY AFTERNOON.
HEATING WILL BE HARD TO COME BY GIVEN THE EXPECTED CLOUD
COVER...BUT IF THE DRY SLOT CAN MANAGE TO INTRODUCE SOME BREAKS IN
THE CLOUDS...MODEL PROJECTIONS OF CAPES IN THE 1000-1500J RANGE
COULD BE REALIZED...HELPING DEVELOP SOME STRONGER UPDRAFTS
INCREASING THE POTENTIAL FOR SEVERE WEATHER. AN EXPECTED LOW LCL
IN THE VERY MOIST ENVIRONMENT WOULD NOT BE A HINDERING FACTOR TO
TORNADO FORMATION SHOULD WE MANAGE TO DEVELOP SOME SUPERCELLS.
SHORT RANGE OPERATIONAL MODELS AGREE IN FORMING A WAVE OR WAVES
ALONG THE FRONT AS IT ENTERS THE MID ATLANTIC STATES...KEEPING
THE RAINFALL GOING OVER EASTERN PA INTO THE EVENING
HOURS. THE RAIN SHOULD TAPER OFF TO SCATTERED SHOWERS OVER MY
EASTERN ZONES AFTER MIDNIGHT.
HIGHS GENERALLY IN THE 70S TODAY WILL BE SOME 5-10 DEG BELOW
NORMAL...WHILE THE OVERNIGHT LOWS WILL BE RELATIVELY MILD FOR
MID AUGUST IN THE MID 50S TO MID 60S.
&&
.SHORT TERM /WEDNESDAY/...
THE SURFACE LOW AND FRONTAL SYSTEM WILL BE MOVING AWAY FROM THE
REGION WEDNESDAY...BUT WITH THE LAGGING UPPER TROUGH AND COLD AIR
ALOFT WE WILL SEE AT LEAST SOME SCATTERED SHOWERS...AND EVEN THE
POSSIBILITY OF A RUMBLE OF THUNDER. MID LEVEL LAPSE RATES ARE NOT
PROGGED TO BE PARTICULARLY IMPRESSIVE SO THE THUNDER CHANCES WILL
NOT BE ESPECIALLY HIGH.
IT WILL BE ANOTHER COOLER THAN NORMAL DAY RANGING FROM THE UPPER
60S TO UPPER 70S NW-SE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MUCH OF THE EXTENDED PERIOD WILL BE DOMINATED BY COOL CYCLONIC
FLOW ALOFT AROUND THE UNSEASONABLY STRONG UPPER LOW/TROUGH THAT
WILL ONLY SLOWLY LIFT THROUGH THE NERN US. THIS SHOULD MEAN A
FAIR AMOUNT OF STRATOCU COOKING UP WITH DAYTIME HEATING AND
PERHAPS A FEW SHOWERS STICKING AROUND INTO THURSDAY.
ENSEMBLES AND THE GFS/ECMWF ALL SHOW UPPER HEIGHTS BEGINNING TO
REBOUND BY THE END OF THE WEEK WITH DRY CONDITIONS FOR FRIDAY AND
SATURDAY. THE DIFFERENCES BEGIN TO ARISE AFTER SATURDAY WITH THE
ECMWF SHOWING A SHARP SHORTWAVE DROPPING DOWN INTO PA FROM NORTH
OF THE LAKES WHILE THE GFS/GEFS INTRODUCE WET WEATHER UNDER A
FLATTER UPPER FLOW IMPLYING WE BECOME VULNERABLE TO CONVECTION
FORMING OVER THE UPPER MIDWEST THAT GETS FUNNELED EAST UNDER THE
MUCH FLATTER UPPER FLOW. GIVEN THE UNCERTAINTY I OPTED FOR A
PRETTY BLAND SMALL MENTION OF SHOWERS THROUGH MONDAY.
FOR THE VERY EXTENDED THE ECMWF SHOWS A RARE...FOR THIS
SUMMER...SURGE IN THE WESTERN ATLANTIC SUBTROPICAL RIDGE WITH 500
MB HEIGHTS EXCEEDING 5900M ALL THE WAY INTO SOUTHERN NEW ENGLAND.
GIVEN THE TENDENCY FOR A TROUGH TO DOMINATE OUR WEATHER MUCH OF
THIS SUMMER...THIS SOLUTION HAS TO BE VIEWED DUBIOUSLY AT THIS
TIME...BUT MAY GIVE HOPE TO REAL SUMMER LOVERS THAT WE COULD HAVE
AT LEAST ONE TRUE HEAT WAVE IN STORE FOR US.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
SHOWERS EXITING THE WESTERN HALF OF THE AREA...ZIPPING ALONG...BUT
THESE SHOULD ALSO SLOW DOWN AND LINE UP MORE S-N AS A LOW PRESSURE
WAVE IN THE LOWER CHESAPEAKE SLIDES NORTHWARD. CIG AND VISBY
BOUNCING ALL OVER THE PLACE AS THE FAST-MOVING SHOWERS GO OVER THE
TERMINALS. THE FRONT/TROUGH APPROACHING FROM THE WEST WILL PRODUCE
NUMEROUS SHRA/TSRA TO OUR WEST AND MOVE THEM INTO THE AREA LATER
THIS AFTN AND EVENING. COVERAGE MAY BE BKN...SO HAVE OPTED TO HOLD
OFF ON MENTIONING T JUST YET. BUT GUSTY WINDS WOULD BE POSS IN
THESE STORMS. THE FRONT PUSHES THROUGH AND WINDS GO WESTERLY AS
THE FRONT MOVES TO THE EAST LATE TONIGHT. RESIDUAL MOISTURE AND
CYCLONIC FLOW SHOULD KEEP LOW MVFR/IFR CIGS OVER MUCH OF THE AREA
TONIGHT.
OUTLOOK...
WED...AM SHRA/LOW CIGS POSSIBLE. OTHERWISE VFR.
THU...AFTN SHRA NW. OTHERWISE VFR.
FRI-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LA CORTE
NEAR TERM...DANGELO/LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...DANGELO/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
705 AM EDT TUE AUG 12 2014
.SYNOPSIS...
A STRONG FRONTAL SYSTEM WILL CROSS THE AREA TODAY AND TONIGHT.
GENERALLY DRIER AND COOLER CONDITIONS CAN BE EXPECTED FOR THE
SECOND HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN ACTIVE DAY IS IN STORE AS A STRONG UPPER TROUGH AND
ACCOMPANYING FRONTAL SYSTEM ENTERS THE REGION. BIGGEST ISSUES
TODAY WILL BE THE POTENTIAL FOR LOCALLY HEAVY RAINS AND
POSSIBILITY OF SEVERE THUNDERSTORMS.
ONCE AGAIN THIS SUMMER WE ARE DEALING WITH A WEATHER SYSTEM
BRINGING UNSEASONABLY STRONG DYNAMICS TO THE FORECAST AREA.
ENSEMBLES AND OPERATIONAL GUIDANCE ALL SHOW A 40-55KT...4-6 STD
DEV...LOW LEVEL SOUTH-SOUTHEASTERLY JET SURGING INTO THE REGION.
THIS HELPS PUSH PWATS IN THE 1.5-2.0 INCH RANGE OVER THE ENTIRE
FCST AREA DURING THE DAY.
THE SETUP SEEMS IS PRIMED FOR A WIDESPREAD MODERATE TO HEAVY RAIN
OVER THE NEXT 12-18 HOURS. HAVE DISCUSSED A POSSIBLE FLOOD WATCH
WITH NEIGHBORING OFFICES AND CONSENSUS IS TO LEAN AWAY FOR THE
TIME BEING GIVEN THE EXPECTED QPF AVERAGING 1-2" AND RECENT
PERIOD OF DRY WEATHER. THE BEST CHANCE FOR DEVELOPING FLOODING
ISSUES SEEMS TO BE ALONG SOME OF THE SMALLER CREEKS AND STREAMS
AND WILL BE HANDLED WITH SHORT TERM ADVISORY/FLOOD PRODUCTS. THE
BEST CHANCE OF THIS WOULD SEEM TO BE OVER ABOUT THE EASTERN HALF
OF MY FCST AREA.
ANOTHER CONCERN IS THAT WHEN THE OCCLUSION/WARM FRONT ENTERS THE
AREA...MARGINAL INSTABILITY AND STRONG SHEAR COULD RESULT IN
SOME LOCALLY SEVERE THUNDERSTORMS WITH AN ISOLATED TORNADO NOT OUT
OF THE QUESTION. RAP AND GFS SHOW A BULLSEYE OF STRONG LOW LEVEL
HELICITY OVER SOUTH CENTRAL PA...IN THE VICINITY OF THE WARM
FRONT THAT WILL BE SLOWLY MOVING NORTH THROUGH EARLY AFTERNOON.
HEATING WILL BE HARD TO COME BY GIVEN THE EXPECTED CLOUD
COVER...BUT IF THE DRY SLOT CAN MANAGE TO INTRODUCE SOME BREAKS IN
THE CLOUDS...MODEL PROJECTIONS OF CAPES IN THE 1000-1500J RANGE
COULD BE REALIZED...HELPING DEVELOP SOME STRONGER UPDRAFTS
INCREASING THE POTENTIAL FOR SEVERE WEATHER. AN EXPECTED LOW LCL
IN THE VERY MOIST ENVIRONMENT WOULD NOT BE A HINDERING FACTOR TO
TORNADO FORMATION SHOULD WE MANAGE TO DEVELOP SOME SUPERCELLS.
SHORT RANGE OPERATIONAL MODELS AGREE IN FORMING A WAVE OR WAVES
ALONG THE FRONT AS IT ENTERS THE MID ATLANTIC STATES...KEEPING
THE RAINFALL GOING OVER EASTERN PA INTO THE EVENING
HOURS. THE RAIN SHOULD TAPER OFF TO SCATTERED SHOWERS OVER MY
EASTERN ZONES AFTER MIDNIGHT.
HIGHS GENERALLY IN THE 70S TODAY WILL BE SOME 5-10 DEG BELOW
NORMAL...WHILE THE OVERNIGHT LOWS WILL BE RELATIVELY MILD FOR
MID AUGUST IN THE MID 50S TO MID 60S.
&&
.SHORT TERM /WEDNESDAY/...
THE SURFACE LOW AND FRONTAL SYSTEM WILL BE MOVING AWAY FROM THE
REGION WEDNESDAY...BUT WITH THE LAGGING UPPER TROUGH AND COLD AIR
ALOFT WE WILL SEE AT LEAST SOME SCATTERED SHOWERS...AND EVEN THE
POSSIBILITY OF A RUMBLE OF THUNDER. MID LEVEL LAPSE RATES ARE NOT
PROGGED TO BE PARTICULARLY IMPRESSIVE SO THE THUNDER CHANCES WILL
NOT BE ESPECIALLY HIGH.
IT WILL BE ANOTHER COOLER THAN NORMAL DAY RANGING FROM THE UPPER
60S TO UPPER 70S NW-SE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MUCH OF THE EXTENDED PERIOD WILL BE DOMINATED BY COOL CYCLONIC
FLOW ALOFT AROUND THE UNSEASONABLY STRONG UPPER LOW/TROUGH THAT
WILL ONLY SLOWLY LIFT THROUGH THE NERN US. THIS SHOULD MEAN A
FAIR AMOUNT OF STRATOCU COOKING UP WITH DAYTIME HEATING AND
PERHAPS A FEW SHOWERS STICKING AROUND INTO THURSDAY.
ENSEMBLES AND THE GFS/ECMWF ALL SHOW UPPER HEIGHTS BEGINNING TO
REBOUND BY THE END OF THE WEEK WITH DRY CONDITIONS FOR FRIDAY AND
SATURDAY. THE DIFFERENCES BEGIN TO ARISE AFTER SATURDAY WITH THE
ECMWF SHOWING A SHARP SHORTWAVE DROPPING DOWN INTO PA FROM NORTH
OF THE LAKES WHILE THE GFS/GEFS INTRODUCE WET WEATHER UNDER A
FLATTER UPPER FLOW IMPLYING WE BECOME VULNERABLE TO CONVECTION
FORMING OVER THE UPPER MIDWEST THAT GETS FUNNELED EAST UNDER THE
MUCH FLATTER UPPER FLOW. GIVEN THE UNCERTAINTY I OPTED FOR A
PRETTY BLAND SMALL MENTION OF SHOWERS THROUGH MONDAY.
FOR THE VERY EXTENDED THE ECMWF SHOWS A RARE...FOR THIS
SUMMER...SURGE IN THE WESTERN ATLANTIC SUBTROPICAL RIDGE WITH 500
MB HEIGHTS EXCEEDING 5900M ALL THE WAY INTO SOUTHERN NEW ENGLAND.
GIVEN THE TENDENCY FOR A TROUGH TO DOMINATE OUR WEATHER MUCH OF
THIS SUMMER...THIS SOLUTION HAS TO BE VIEWED DUBIOUSLY AT THIS
TIME...BUT MAY GIVE HOPE TO REAL SUMMER LOVERS THAT WE COULD HAVE
AT LEAST ONE TRUE HEAT WAVE IN STORE FOR US.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
SHOWERS CONTINUE TO STREAM THROUGH CENTRAL PA THIS MORNING. THESE
SHOWERS...HEAVY AT TIMES. WILL CONTINUE TO ALLOW FOR IFR CIGS AT
BFD...JST...AOO AND AT TIMES...UNV. THESE SHOWERS ARE DUE TO A
SLOW MOVING WARM FRONT TREKKING THROUGH PENNSYLVANIA TODAY.
BFD..JST AND AOO DUE TO UPSLOPE FLOW REMAINS IFR. THESE CONDITIONS
WILL PERSIST THROUGH MID MORNING...BEFORE IMPROVING SLIGHTLY TO
MVFR BY THE EARLY AFTERNOON HOURS AFTER THE WARM FRONT LIFTS
THROUGH THE AREA. A TROUGH OF LOW PRESSURE APPROACHING FROM THE
WEST WILL PRODUCE NUMEROUS SHRA/TSRA...WHICH COULD PRODUCE BRIEF
IFR VSBYS AND GUSTY WINDS DURING THE AFTERNOON AND EARLY EVENING
HOURS.
CIGS AND VSBYS ELSEWHERE SHOULD BE MVFR AT TIMES WITH POSSIBLE IFR
IN SHRA/TSRA THIS EVENING ACROSS THE EASTERN TAF SITES.
OUTLOOK...
TUE NIGHT...SHRA/TSRA. LOW CIGS/VSBYS POSSIBLE.
WED...AM SHRA/LOW CIGS POSSIBLE.
THU-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
559 AM CDT TUE AUG 12 2014
.AVIATION...
LIGHT WINDS AND VFR CONDITIONS ARE EXPECTED TODAY AND TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 350 AM CDT TUE AUG 12 2014/
SHORT TERM...
A FEW LINGERING SHOWERS SHOULD PUSH OUT OF THE FCST AREA BY FCST
VALID TIME AS MODEST UPPER LEVEL JET STREAKS EXITS TO THE EAST FROM
SRN OKLAHOMA. MODELS CONTINUE TO PROG DRIER LOW TO MID LEVEL AIR
ADVECTING INTO THE REGION...AND LOOKING AT WATER VAPOR IMAGERY AND
SFC OBS CANNOT REALLY DISPUTE THAT ATTM. LAST PLACE TO GET THE DRIER
AIR TODAY WILL BE THE SWRN CORNER OF THE FCST AREA WITH THE WRF-NAM
IN PARTICULAR. COULD SEE SOME ISOLATED SHOWERS DEVELOP THIS AFTN AS
THE AIR MASS THERE DESTABILIZES AS THE WRF-NAM AND HRRR SUGGEST.
CONFIDENCE IS LOW AND COVERAGE EXPECTED TO BE LIMITED ATTM SO WILL
KEEP POPS BELOW MENTION BUT WILL BE SOMETHING TO WATCH THROUGH THE
DAY. OTHERWISE TEMPS NOT TOO DIFFERENT THAN SEEN YESTERDAY AND IN
LINE OR JUST A DEGREE OR TWO BELOW MOS LOOKING FINE.
LONG TERM...
MODELS ARE IN GOOD AGREEMENT THROUGH THE END OF THE WEEK INTO THE
BEGINNING OF THE WEEKEND...PERSISTENT UPPER LEVEL RIDGE OVER THE
ROCKIES SLOWLY MIGRATES EASTWARD THROUGH THE WEEK RESULTING IN HIGH
PRESSURE ACROSS WEST TEXAS...BY SATURDAY A NUMBER OF UPPER LEVEL
DISTURBANCES BEGIN TO BREAK THE RIDGE DOWN DUE TO A NUMBER OF
SHORTWAVES EJECTING EASTWARD AND MONSOONAL FLOW OUT OF THE PACIFIC
WEST...GFS/ECMWF BEGIN TO DIVERGE SOMEWHAT ON SATURDAY AT
120HRS...GFS WORKS THE UPPER LEVEL INSTABILITY EASTWARD QUICKER THAN
THE ECMWF WHICH DEVELOPS A CLOSED LOW OVER THE CENTRAL PLAINS
RESULTING IN COLD FRONT EXTENDING FROM CENTRAL KANSAS THROUGH WEST
TEXAS SATURDAY NIGHT INTO SUNDAY WHICH WAS HINTED AT IN PREVIOUS
RUNS...THUS INCREASED POPS SLIGHTLY TOWARD THE END OF THE WEEKEND
MAINTAINING SIMILAR TREND OF PREVIOUS FORECAST...KEPT TEMPS IN NEAR
SEASONAL TO SLIGHTLY COOLER...IF WE STAY DRY TEMPS MAY APPROACH THE
100S OFF THE CAPROCK BY THE END OF THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 87 61 90 64 90 / 10 10 10 0 0
TULIA 89 62 91 65 92 / 0 0 0 0 0
PLAINVIEW 87 62 91 65 91 / 0 0 0 0 0
LEVELLAND 88 64 91 66 92 / 10 0 0 0 0
LUBBOCK 90 65 93 69 93 / 10 0 0 0 0
DENVER CITY 87 64 92 66 92 / 10 10 0 0 0
BROWNFIELD 89 65 92 67 93 / 10 0 0 0 0
CHILDRESS 92 67 95 70 97 / 0 0 0 0 0
SPUR 91 65 94 68 95 / 10 0 0 0 0
ASPERMONT 94 67 96 70 96 / 10 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07/55/07
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
636 AM CDT TUE AUG 12 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM CDT TUE AUG 12 2014
MAIN FORECAST CONCERNS...VALLEY FOG LATE TONIGHT...TEMPERATURES.
DATA ANALYSIS AT 06Z HAD A 1003MB LOW OVER EASTERN LOW MI AND HIGH
PRESSURE OVER THE CENTRAL/NORTHERN PLAINS. CLOUDS MAINLY CONFINED TO
THE EAST HALF OF WI/NORTH-EAST IL...WITH SHRA PERSISTING OVER
NORTHEAST WI AHEAD OF THE MID LEVEL THROUGH/SHORTWAVE. DECREASING
CLOUDS/CLEAR SKIES ELSEWHERE ACROSS THE UPPER MIDWEST AS THE PLAINS
HIGH SLOWLY MOVED EAST. MODEST PRESSURE GRADIENT BETWEEN THE
LOW/HIGH ACROSS MUCH OF MN/IA/WI EARLY THIS MORNING WITH NORTHWEST
WINDS OF 5-15 MPH COMMON...KEEPING THE BOUNDARY LAYER STIRRED...
LIMITING THE TEMP DROP AND FOG FORMATION.
12.00Z MODELS INITIALIZED WELL AND OFFER QUITE SIMILAR SOLUTIONS FOR
TODAY/TONIGHT AS THE STRONG MID LEVEL TROUGH EXITS EAST AND HGTS
SLOWLY RISE ACROSS THE WESTERN GREAT LAKES REGION. TREND FAVORS A
COMPROMISE OF THE EARLIER RUNS WITH FCST CONFIDENCE ON THE GOOD SIDE
FOR TODAY/TONIGHT...AS QUIET/COOL/DRIER CANADIAN HIGH PRESSURE
BUILDS IN.
IN THE SHORT TERM...A GENERALLY QUIET PERIOD TODAY/TONIGHT AS THE
HIGH IN THE PLAINS SLOWLY MOVES EAST INTO THE REGION. MODEST
PRESSURE GRADIENT REMAINS OVER THE AREA TODAY. MODEL SOUNDINGS SHOW
DIURNAL WARMING/MIXING TO AROUND 825MB WITH 20-25KTS OF WIND IN THE
UPPER THIRD OF THIS MIXED LAYER. ADDED A BIT MORE WIND/WIND GUSTS TO
THE FCST GRIDS FOR THE LATE MORNING/AFTERNOON HOURS TODAY. MODELS DO
DIFFER ON AMOUNT OF MOISTURE IN THE MIXED LAYER...IMPACTING EXTENT
OF DIURNAL CUMULUS. SOME WOULD SAY TOO DRY FOR DIURNAL CUMULUS WHILE
OTHERS WOULD DEVELOP A SCT LCL BKN CUMULUS DECK. BASED ON THE 12.00Z
KINL/KMPX RAOBS AND UPSTREAM SFC DEW POINTS DROPPING INTO THE LOWER
50S...SIDED WITH THE DRIER MODELS AND A FEW CUMULUS AT MOST TODAY.
COOLEST OF THE 850MB AIR SLIDES ACROSS THE AREA TODAY. MIXED 850MB
TEMPS AND PLENTY OF SUNSHINE SUPPORT HIGHS IN THE MID-UPPER 70S.
GRADIENT RELAXES TONIGHT AS THE HIGH MOVES INTO MO/IA...ENOUGH FOR
SOME DECOUPLING IN THE RIVER VALLEYS/LOW LAYING AREAS LATER TONIGHT.
MODEL SOUNDINGS HAVE TRENDED MORE TOWARD 10-15KTS OF NORTHWEST WIND
JUST ABOVE THE BOUNDARY LAYER LATER TONIGHT...LESS FAVORABLE FOR
VALLEY FOG FORMATION IN THE MS RIVER VALLEY. WITH A DEEP DRY AIRMASS
OVER THE REGION AND SUBSIDENCE THRU THE MID/UPPER LEVELS...FAVORABLE
FOR STRONGER RADIATIONAL COOLING...WILL LEAVE THE PATCHY TO AREAS OF
VALLEY FOG LATER TONIGHT IN THE GRIDS FOR NOW. GIVEN THE STRONGER
RADIATIONAL COOLING POTENTIAL...TRENDED TOWARD COOLER OF GUIDANCE
LOWS TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 339 AM CDT TUE AUG 12 2014
MAIN FORECAST CONCERNS FOR WED THROUGH THU NIGHT...SMALL SHRA/TSRA
CHANCES WED AFTERNOON...TEMPERATURES.
MODELS REMAIN IN RATHER GOOD AGREEMENT WED THRU THU NIGHT AS A MID
LEVEL LOW DEVELOPS OVER WESTERN QUEBEC AND ANOTHER MID LEVEL LOW
MOVES INTO OR/WA...WITH RIDGING IN BETWEEN ACROSS CENTRAL NOAM. SOME
DETAIL DIFFERENCES WITH SHORTWAVES COMING OUT OF THE OR/WA TROUGHING
BY THU/THU NIGHT. HOWEVER THE UPPER MIDWEST REMAINS EAST OF THE
RIDGE AXIS AND UNDER MAINLY QUIET NORTHWEST FLOW ALOFT THRU THU
NIGHT. FCST CONFIDENCE IN THE WED THRU THU NIGHT PERIOD IS GOOD.
RATHER CONSISTENT MODEL SIGNAL FOR SHORTWAVE ENERGY DROPPING ACROSS
LK SUPERIOR ON WED TO SEND A /BACKDOOR/ COLD FRONT SOUTHWARD THRU
THE AREA. TROUGH AT 925-850MB AS WELL. PW VALUES PROGGED TO INCREASE
TO AROUND 1 INCH WITH MODEST SFC-850MB FN CONVERGENCE TO ACCOMPANY
THIS FEATURE. SOME 850-700MB FN CONVERGENCE AS WELL. MODEL PROGS
SHOWING AS MUCH AS 250-1000 J/KG OF MUCAPE ACROSS THE AREA WED
AFTERNOON. HOWEVER MODEL SOUNDINGS INDICATE MUCH LESS CAPE...MORE IN
THE 50-200 J/KG RANGE...WITH POTENTIAL CAPPING AROUND 700MB. BULK OF
MODELS INCLUDING HI-RES WRF MODELS CONTINUE TO PRODUCE SOME VERY
LIGHT QPF ACROSS THE AREA WITH THIS BOUNDARY/TROUGH WED AFTERNOON.
GIVEN THIS...WILL LEAVE THE SPRINKLE MENTION IN THE GRIDS FOR NOW.
MAY YET NEED TO SHIFT ANY SMALL -SHRA CHANCE WED AFTERNOON FURTHER
SOUTH/WEST ACROSS THE FCST AREA DEPENDING ON WHERE THE BOUNDARY IS
DURING PEAK HEATING.
WED NIGHT THRU THU NIGHT TREND DRY/QUIET. THIS WITH THE AREA
REMAINING EAST OF THE MID LEVEL RIDGE AXIS AND STRONGER PIECES OF
ENERGY EJECTING OUT OF THE NORTHWEST CONUS TROUGH ONLY INTO THE
CENTRAL/NORTHERN PLAINS BY 12Z FRI. BOUNDARY FROM WED SAGS SOUTH OF
THE AREA/DISSIPATES WED NIGHT WITH HIGH PRESSURE AGAIN BUILDING OVER
THE WESTERN GREAT LAKES FOR WED NIGHT THRU THU NIGHT. WITH HIGH
PRESSURE CENTERED OVER WI BY 12Z THU FOR LIGHT/CALM WINDS AND
CLEAR/MOSTLY CLEAR SKIES...ADDED A PATCHY VALLEY FOG MENTION TO
GRIDS FOR LATE WED NIGHT/EARLY THU MORNING. LOWER LEVEL THERMAL
RIDGE AND MAIN AXIS OF MOISTURE/MOISTURE TRANSPORT/INSTABILITY REMAIN
WEST OF THE AREA THRU THU NIGHT. REMOVED THE SMALL SHRA/TSRA CHANCES
FROM THU NIGHT. BLEND OF THE NUMERICAL TEMPERATURE GUIDANCE FOR WED
THRU THU NIGHT LOOKS TO HAVE HIGHS/LOWS WELL TRENDED.
FOR FRIDAY THROUGH MONDAY.../DAYS 4 TO 7/...
MAIN FORECAST CONCERNS...SHRA/TSRA CHANCES THRU MUCH OF THE
PERIOD...TEMPERATURES.
12.00Z MEDIUM RANGE MODEL CONSENSUS SHOWS A BREAK-DOWN OF THE
CENTRAL NOAM RIDGING IN THE FRI-SUN PERIOD. FIRST AS SHORTWAVE
ENERGY EJECTING OUT OF THE NORTHWEST CONUS TROUGH COMES THRU IT
FRI/SAT THEN AS THE NORTHWEST CONUS TROUGH/REMNANTS MOVE EAST
SUN/MON. PLENTY OF DETAIL DIFFERENCES BY FRI/SAT...WHICH WOULD HAVE
IMPACTS ON THE SENSIBLE WEATHER ACROSS MN/IA/WI. DIFFERENCES
CONTINUE SUN/MON. OVERALL DAY-TO-DAY FCST CONFIDENCE IN THE FRI-MON
PERIOD IS BELOW AVERAGE...FOR WHAT LOOKS TO BE A MORE ACTIVE/
UNSETTLED PERIOD.
LEAD SHORTWAVE/S/ COMING THRU THE RIDGING PUSH THE MOISTURE AXIS/
INSTABILITY EASTWARD INTO THE REGION FRI. PW VALUES INCREASE INTO
THE 1.5 INCH RANGE FRI WITH MUCAPE IN THE 500-1500 J/KG RANGE FOR
THE AFTERNOON. CONCERN IS LACK OF TRIGGER/FOCUS MECHANISM FOR
CONVECTION. LEFT MOST OF THE AREA DRY FRI. MOISTURE CONTINUES TO
SLOWLY INCREASE FOR SAT THRU MON...WITH CONTINUED APPROACH OF PIECES
OF SHORTWAVE ENERGY AND GRADUALLY FALLING HGTS. SHRA/TSRA CHANCES
LOOK TO SLOWLY INCREASE FOR SAT THRU MON AND THIS WELL TRENDED BY
THE MODEL/ENSEMBLE CONSENSUS. AGAIN...PLENTY OF DETAIL DIFFERENCES
WITH SHORTWAVES AND TIMING THRU THIS PERIOD...AND NOT EVERY FRI
NIGHT THRU MON PERIOD WILL END UP WITH SHRA/TSRA CHANCES ONCE
THESE DIFFERENCES SORT THEMSELVES OUT. WITH A RETURN TO MORE
SOUTHERLY FLOW/LOW LEVEL WARMING...MODEL CONSENSUS HIGHS/LOWS NEAR
TO ABOVE NORMAL FOR FRI-MON APPEAR WELL TRENDED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 625 AM CDT TUE AUG 12 2014
LOW STRATUS/PATCHY ADVECTION FOG ACROSS NORTHWEST WI IS OOZING
SOUTHWARD ALONG THE ST. CROIX RIVER VALLEY AND INTO SOUTHEAST
MN IMPACTING KRST. 12.10Z RAP SUGGESTS THESE CLOUDS/FOG SHOULD
QUICKLY DISSIPATE BY 14Z AND WILL ADJUST TAF TO ACCOUNT FOR THESE
TRENDS. FARTHER EAST AT KLSE...NOT EXPECTING WIDESPREAD LOWER
CEILINGS WITH SCATTERED CLOUD BASES AROUND 1200 FT AGL.
FOR THE REST OF THE FORECAST PERIOD...EXPECT SOME AFTERNOON
THERMAL CUMULUS IN THE 3000 TO 4000 FT AGL LAYER. NORTHWEST WIND
WILL BE BREEZY WITH OCCASIONAL GUSTS TO 25 KTS. WINDS WILL BECOME
LIGHT AND VARIABLE AFTER SUNSET WITH THE POTENTIAL FOR VALLEY FOG
DEVELOPMENT AT KLSE AFTER 13.08Z DUE TO NEAR SURFACE SATURATION...
STEEP NOCTURNAL THERMAL INVERSION AND LIGHT WIND.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...ROGERS
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
1108 AM MST TUE AUG 12 2014
...POTENTIAL FOR LOCALIZED FLASH FLOODING TODAY AND TONIGHT ACROSS
MUCH OF THE AREA...
.SYNOPSIS...
MOISTURE LEVELS WILL CONTINUE TO INCREASE TODAY AHEAD OF AN
APPROACHING LOW PRESSURE SYSTEM. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TODAY AND TONIGHT ACROSS MUCH OF THE AREA. SOME STORMS WILL
BE CAPABLE OF PRODUCING VERY HEAVY RAIN AND AREAS OF FLOODING. WITH
THE MOIST CONDITIONS...TEMPERATURES WILL REMAIN BELOW NORMAL THE
NEXT FEW DAYS. A DRYING AND WARMING TREND IS EXPECTED LATE IN THE
WEEK AS HIGH PRESSURE BECOMES REESTABLISHED TO THE SOUTH.
&&
.DISCUSSION...
CONVECTIVELY ACTIVE DAY HAS STARTED TO RAMP UP SOMEWHAT THIS MORNING
AS FAVORABLE ATMOSPHERIC DYNAMICS COMBINE WITH A VERY MOIST
ENVIRONMENT. THE PRIMARY INVERTED TROUGH/VORTICITY CENTER WAS
PROPAGATING NORTH NEARING THE INTERNATIONAL BORDER SOUTHWEST OF
TUCSON...WHILE A LEADING CONVECTIVELY GENERATED VORTICITY MAX WAS
SUPPORTING DEVELOPING CONVECTION NEAR THE YUMA AREA. 12Z KPSR AND
KTWC SOUNDINGS DEPICTED DEEP SELY MOIST FLOW THROUGH THE LOWER AND
MIDDLE TROPOSPHERE CHARACTERIZED BY PWATS 1.75 INCHES AND LOW LEVEL
MIXING RATION 11-12 G/KG (NEAR 2 STANDARD DEVIATIONS ABOVE AVERAGE).
OBJECTIVE ANALYSIS SUGGESTS PWATS IN EXCESS OF 2 INCHES ADVECTING
NORTH TOWARDS THE CWA...WHILE DIFLUENCE ALOFT AND FORCED ASCENT
INCREASE ACROSS THE REGION.
AT 9AM...SFC TEMPERATURES HAVE RISEN INTO THE MID 80S TO MID 90S
(OUTSIDE OF THUNDERSTORMS THAT HAVE CONTINUED SINCE EARLIER IN THE
DAY) DESPITE THE THIN VEIL OF CIRRUS FROM EARLIER SONORAN COMPLEX.
BASED ON 12Z SOUNDING DATA AND FORECAST NAM-WRF BUFR
SOUNDINGS...ONCE TEMPERATURES REACH 98-100 DEGREES THE ENVIRONMENT
WILL BECOME CONVECTIVELY UNSTABLE (MLCAPES NEARING 1000 J/KG) WITH
LITTLE TO NO INHIBITION. WHILE LAPSE RATES ARE NOT PARTICULARLY
STEEP...TALL SKINNY CAPE PROFILES WITH THICK MOISTURE SUPPORT
LOCALLY HEAVY RAIN PRODUCING CELLS (AND POTENTIALLY A COUPLE
MOISTURE LOADED UPDRAFT/DOWNBURST CELLS). WILL CONTINUE FLASH FLOOD
WATCH BASED MOSTLY ON PRECIP RATE EXPECTATION OVER POPULATION
CENTERS AS CELL PROPAGATION MAY PRECLUDE A WIDESPREAD FLOOD THREAT
(UNLESS LOCAL TRAINING ECHOES SET UP). OTHERWISE...MADE MINOR
ADJUSTMENTS TO TEMPS AND POPS FOR THE REMAINDER OF THE MORNING BASED
ON CURRENT TRENDS.
&&
.PREVIOUS DISCUSSION...
/605 AM MST TUE AUG 12 2014/
LATEST RAP STREAMLINE ANALYSIS SHOWS THE MID-TROPOSPHERIC HIGH
POSITIONED NEAR THE FOUR CORNERS. FURTHER SOUTH...A WELL-DEFINED
INVERTED TROUGH IS APPARENT ACROSS SONORA WHILE THUNDERSTORMS
ASSOCIATED WITH AN MCS PERSIST EARLY THIS MORNING. BETWEEN THE TWO
SYSTEMS...THE STEERING FLOW IS GENERALLY SOUTHEASTERLY AROUND 15 KT.
ACROSS THE FORECAST AREA...SCATTERED SHOWERS HAVE REDEVELOPED ACROSS
THE LOWER DESERTS...INCLUDING PORTIONS OF THE PHOENIX METRO AREA.
ALTHOUGH CAPE IS GENERALLY LACKING AT THIS HOUR...WEAK VORTICITY AND
JET-FORCED ASCENT ALONG WITH REMNANT OUTFLOW BOUNDARIES ARE
CONTRIBUTING TO THE NOCTURNAL CONVECTION.
CLASSIC SETUP FOR ACTIVE WEATHER IS IN PLACE AND ALL SIGNS POINT TO
FAVORABLE CONDITIONS FOR ADDITIONAL STORM DEVELOPMENT AS EARLY AS
THIS MORNING ACROSS THE REGION. LATEST GPS-IPW AT TEMPE REGISTERED
AS HIGH AS 1.85 INCHES. MODELS INDICATE THAT THE ATMOSPHERE WILL
CONTINUE TO SATURATE AND ALONG WITH INCREASING DEEP LAYER
FLOW...STRONGER INSTABILITY AND SYNOPTIC ASCENT AHEAD OF THE
APPROACHING VORT MAX...SHOWERS AND THUNDERSTORMS WILL LIKELY BECOME
WIDESPREAD DURING THE AFTERNOON AND EVENING. GIVEN THE ANOMALOUSLY
(150-200% OF NORMAL) MOIST PROFILE...FLASH FLOODING WILL BE THE
PRIMARY THREAT AND A FLASH FLOOD WATCH HAS BEEN ISSUED FOR A LARGE
PORTION OF THE AREA. POPS WERE ALSO INCREASED TO AROUND 70 PERCENT
FOR THE PHOENIX AREA AND AS HIGH AS 80 PERCENT ACROSS THE HIGHER
TERRAIN OF SOUTHERN GILA COUNTY. GLOBAL AND CONVECTIVE ALLOWING
MODELS ARE STILL SOMEWHAT UNCERTAIN WITH REGARD TO THE EXACT SPEED
OF THE TROUGH AS IT LIFTS NORTHWARD THROUGH THE FORECAST AREA.
CONSEQUENTLY...THE POTENTIAL FOR HEAVY RAIN WILL OCCUR OVER A
RELATIVELY LONG TIME WINDOW...PERHAPS EVEN CONTINUING INTO WEDNESDAY
MORNING MAINLY FROM PHOENIX NORTHWARD. SOME LOCATIONS MAY SEE STORM
TOTALS IN EXCESS OF 1.0-1.5 INCHES.
AFOREMENTIONED VORT MAX WILL ACCELERATE SOMEWHAT WEDNESDAY AS IT
LIFTS NORTHEASTWARD INTO NORTHERN ARIZONA. BELOW NORMAL TEMPERATURES
ARE A GOOD BET GIVEN THE DEEP MOISTURE AND RESIDUAL RAIN-COOLED AIR.
HIGH TEMPERATURES WERE LOWERED INTO THE MID 90S FOR THE PHOENIX
AREA. BEST CHANCE FOR PRECIPITATION APPEARS TO BE ACROSS THE HIGHER
TERRAIN NORTH AND EAST OF PHOENIX. HOWEVER...A MOIST SOUTHWESTERLY
FLOW SUGGESTS THE POSSIBILITY OF BACK-BUILDING CELLS INTO THE LOWER
DESERTS AND POPS WERE INCREASED TO 50 PERCENT IN THESE AREAS.
A DRIER SOUTHWESTERLY FLOW WILL DEVELOP IN THE WAKE OF THE LOW
PRESSURE SYSTEM BY THURSDAY...WHICH WILL CONFINE THUNDERSTORMS
MAINLY TO THE HIGHER TERRAIN OF NORTHERN AND EASTERN AZ. A WARMING
AND DRYING TREND IS ALSO EXPECTED LATE IN THE WEEK AND INTO EARLY
NEXT WEEK AS THE MONSOON HIGH DRIFTS SOUTHWARD...GIVING WAY TO MORE
OF A WESTERLY FLOW.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS SE ARIZONA
THROUGH NOON AND THEN MOVE INTO THE PHOENIX AREA AFFECTING TERMINALS
SOMETIME FROM EARLY AFTERNOON THROUGH EARLY EVENING. WILL LIKELY ADD
IN A TEMPO OR PREDOMINANT GROUP FOR THUNDERSTORMS ONCE WE HAVE A
BETTER TIMEFRAME OF STORMS MOVING THROUGH THE AREA. HAVE FAIRLY HIGH
CONFIDENCE IN AT LEAST BRIEF TIME...LESS THAN AN HOUR MOST
LIKELY...OF MVFR CIGS/VSBYS DUE TO SHOWERS AND STORMS MOVING THROUGH
THE METRO AREA. EXPECTING A BREAK IN THE RAIN FROM AROUND MID
EVENING THROUGH MUCH OF THE OVERNIGHT...BUT CIGS AROUND 6-8K FEET
SHOULD PERSIST. ANOTHER ROUND OF SHOWERS AND POSSIBLY A THUNDERSTORM
OR TWO IS EXPECTED AGAIN DURING THE DAYTIME WEDNESDAY.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS AFTERNOON WITH
A FAIRLY GOOD CHANCE OF AFFECTING BOTH KIPL AND KBLH AT LEAST FOR A
BRIEF TIME. CHANCES FOR STORMS WILL DIMINISH BY EARLY EVENING WITH
LINGERING CIGS AROUND 8K LIKELY LASTING JUST PAST MIDNIGHT. GRADUAL
CLEARING IS EXPECTED BY SUNRISE WEDNESDAY MORNING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
DRIER AIR WILL FILTER INTO THE DISTRICT BEGINNING THURSDAY...WITH
MORE PREVALENT CLEAR SKIES AND LOWER HUMIDITIES OVER THE WEEKEND.
THE BEST CHANCES FOR RAINFALL THURSDAY AND FRIDAY WILL BE OVER GILA
COUNTY AS SOME RESIDUAL MOISTURE LINGERS OVER HIGHER TERRAIN. WITH
NEAR AVERAGE TEMPERATURES...AFTERNOON RELATIVE HUMIDITY VALUES
FALLING INTO A 25-40 PERCENT RANGE THURSDAY WILL DRY TOWARDS A 10-25
PERCENT RANGE BY THE WEEKEND. OVERNIGHT RECOVERY WILL BE GOOD TO
EXCELLENT. OUTSIDE OF ANY GUSTY THUNDERSTORM WINDS
THURSDAY...TYPICAL LIGHT SUMMER WINDS WILL PREVAIL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FLASH FLOOD WATCH FROM NOON MST TODAY THROUGH WEDNESDAY MORNING
AZZ020>028.
CA...FLASH FLOOD WATCH FROM NOON PDT TODAY THROUGH WEDNESDAY MORNING
CAZ031>033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...MO/HIRSCH
AVIATION....KUHLMAN
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
915 AM MST TUE AUG 12 2014
...POTENTIAL FOR LOCALIZED FLASH FLOODING TODAY AND TONIGHT ACROSS
MUCH OF THE AREA...
.SYNOPSIS...
MOISTURE LEVELS WILL CONTINUE TO INCREASE TODAY AHEAD OF AN
APPROACHING LOW PRESSURE SYSTEM. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TODAY AND TONIGHT ACROSS MUCH OF THE AREA. SOME STORMS WILL
BE CAPABLE OF PRODUCING VERY HEAVY RAIN AND AREAS OF FLOODING. WITH
THE MOIST CONDITIONS...TEMPERATURES WILL REMAIN BELOW NORMAL THE
NEXT FEW DAYS. A DRYING AND WARMING TREND IS EXPECTED LATE IN THE
WEEK AS HIGH PRESSURE BECOMES REESTABLISHED TO THE SOUTH.
&&
.DISCUSSION...
CONVECTIVELY ACTIVE DAY HAS STARTED TO RAMP UP SOMEWHAT THIS MORNING
AS FAVORABLE ATMOSPHERIC DYNAMICS COMBINE WITH A VERY MOIST
ENVIRONMENT. THE PRIMARY INVERTED TROUGH/VORTICITY CENTER WAS
PROPAGATING NORTH NEARING THE INTERNATIONAL BORDER SOUTHWEST OF
TUCSON...WHILE A LEADING CONVECTIVELY GENERATED VORTICITY MAX WAS
SUPPORTING DEVELOPING CONVECTION NEAR THE YUMA AREA. 12Z KPSR AND
KTWC SOUNDINGS DEPICTED DEEP SELY MOIST FLOW THROUGH THE LOWER AND
MIDDLE TROPOSPHERE CHARACTERIZED BY PWATS 1.75 INCHES AND LOW LEVEL
MIXING RATION 11-12 G/KG (NEAR 2 STANDARD DEVIATIONS ABOVE AVERAGE).
OBJECTIVE ANALYSIS SUGGESTS PWATS IN EXCESS OF 2 INCHES ADVECTING
NORTH TOWARDS THE CWA...WHILE DIFLUENCE ALOFT AND FORCED ASCENT
INCREASE ACROSS THE REGION.
AT 9AM...SFC TEMPERATURES HAVE RISEN INTO THE MID 80S TO MID 90S
(OUTSIDE OF THUNDERSTORMS THAT HAVE CONTINUED SINCE EARLIER IN THE
DAY) DESPITE THE THIN VEIL OF CIRRUS FROM EARLIER SONORAN COMPLEX.
BASED ON 12Z SOUNDING DATA AND FORECAST NAM-WRF BUFR
SOUNDINGS...ONCE TEMPERATURES REACH 98-100 DEGREES THE ENVIRONMENT
WILL BECOME CONVECTIVELY UNSTABLE (MLCAPES NEARING 1000 J/KG) WITH
LITTLE TO NO INHIBITION. WHILE LAPSE RATES ARE NOT PARTICULARLY
STEEP...TALL SKINNY CAPE PROFILES WITH THICK MOISTURE SUPPORT
LOCALLY HEAVY RAIN PRODUCING CELLS (AND POTENTIALLY A COUPLE
MOISTURE LOADED UPDRAFT/DOWNBURST CELLS). WILL CONTINUE FLASH FLOOD
WATCH BASED MOSTLY ON PRECIP RATE EXPECTATION OVER POPULATION
CENTERS AS CELL PROPAGATION MAY PRECLUDE A WIDESPREAD FLOOD THREAT
(UNLESS LOCAL TRAINING ECHOES SET UP). OTHERWISE...MADE MINOR
ADJUSTMENTS TO TEMPS AND POPS FOR THE REMAINDER OF THE MORNING BASED
ON CURRENT TRENDS.
&&
.PREVIOUS DISCUSSION...
/605 AM MST TUE AUG 12 2014/
LATEST RAP STREAMLINE ANALYSIS SHOWS THE MID-TROPOSPHERIC HIGH
POSITIONED NEAR THE FOUR CORNERS. FURTHER SOUTH...A WELL-DEFINED
INVERTED TROUGH IS APPARENT ACROSS SONORA WHILE THUNDERSTORMS
ASSOCIATED WITH AN MCS PERSIST EARLY THIS MORNING. BETWEEN THE TWO
SYSTEMS...THE STEERING FLOW IS GENERALLY SOUTHEASTERLY AROUND 15 KT.
ACROSS THE FORECAST AREA...SCATTERED SHOWERS HAVE REDEVELOPED ACROSS
THE LOWER DESERTS...INCLUDING PORTIONS OF THE PHOENIX METRO AREA.
ALTHOUGH CAPE IS GENERALLY LACKING AT THIS HOUR...WEAK VORTICITY AND
JET-FORCED ASCENT ALONG WITH REMNANT OUTFLOW BOUNDARIES ARE
CONTRIBUTING TO THE NOCTURNAL CONVECTION.
CLASSIC SETUP FOR ACTIVE WEATHER IS IN PLACE AND ALL SIGNS POINT TO
FAVORABLE CONDITIONS FOR ADDITIONAL STORM DEVELOPMENT AS EARLY AS
THIS MORNING ACROSS THE REGION. LATEST GPS-IPW AT TEMPE REGISTERED
AS HIGH AS 1.85 INCHES. MODELS INDICATE THAT THE ATMOSPHERE WILL
CONTINUE TO SATURATE AND ALONG WITH INCREASING DEEP LAYER
FLOW...STRONGER INSTABILITY AND SYNOPTIC ASCENT AHEAD OF THE
APPROACHING VORT MAX...SHOWERS AND THUNDERSTORMS WILL LIKELY BECOME
WIDESPREAD DURING THE AFTERNOON AND EVENING. GIVEN THE ANOMALOUSLY
(150-200% OF NORMAL) MOIST PROFILE...FLASH FLOODING WILL BE THE
PRIMARY THREAT AND A FLASH FLOOD WATCH HAS BEEN ISSUED FOR A LARGE
PORTION OF THE AREA. POPS WERE ALSO INCREASED TO AROUND 70 PERCENT
FOR THE PHOENIX AREA AND AS HIGH AS 80 PERCENT ACROSS THE HIGHER
TERRAIN OF SOUTHERN GILA COUNTY. GLOBAL AND CONVECTIVE ALLOWING
MODELS ARE STILL SOMEWHAT UNCERTAIN WITH REGARD TO THE EXACT SPEED
OF THE TROUGH AS IT LIFTS NORTHWARD THROUGH THE FORECAST AREA.
CONSEQUENTLY...THE POTENTIAL FOR HEAVY RAIN WILL OCCUR OVER A
RELATIVELY LONG TIME WINDOW...PERHAPS EVEN CONTINUING INTO WEDNESDAY
MORNING MAINLY FROM PHOENIX NORTHWARD. SOME LOCATIONS MAY SEE STORM
TOTALS IN EXCESS OF 1.0-1.5 INCHES.
AFOREMENTIONED VORT MAX WILL ACCELERATE SOMEWHAT WEDNESDAY AS IT
LIFTS NORTHEASTWARD INTO NORTHERN ARIZONA. BELOW NORMAL TEMPERATURES
ARE A GOOD BET GIVEN THE DEEP MOISTURE AND RESIDUAL RAIN-COOLED AIR.
HIGH TEMPERATURES WERE LOWERED INTO THE MID 90S FOR THE PHOENIX
AREA. BEST CHANCE FOR PRECIPITATION APPEARS TO BE ACROSS THE HIGHER
TERRAIN NORTH AND EAST OF PHOENIX. HOWEVER...A MOIST SOUTHWESTERLY
FLOW SUGGESTS THE POSSIBILITY OF BACK-BUILDING CELLS INTO THE LOWER
DESERTS AND POPS WERE INCREASED TO 50 PERCENT IN THESE AREAS.
A DRIER SOUTHWESTERLY FLOW WILL DEVELOP IN THE WAKE OF THE LOW
PRESSURE SYSTEM BY THURSDAY...WHICH WILL CONFINE THUNDERSTORMS
MAINLY TO THE HIGHER TERRAIN OF NORTHERN AND EASTERN AZ. A WARMING
AND DRYING TREND IS ALSO EXPECTED LATE IN THE WEEK AND INTO EARLY
NEXT WEEK AS THE MONSOON HIGH DRIFTS SOUTHWARD...GIVING WAY TO MORE
OF A WESTERLY FLOW.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
A MUCH WETTER PATTERN FOR THE NEXT 24 HOURS OR SO...WITH SCATTERED
TO WIDESPREAD SHOWERS AND THUNDERSTORMS ACROSS THE REGION...TOPS
GENERALLY 38-42KFT. EXPECT SCT-BKN CLOUD DECKS AOA 8000 FT...LOCAL
CIGS AS LOW AS 6000 FT AND VISIBILITY DOWN TO 4SM IN HEAVY RAIN WITH
STRONGER STORMS. ANTICIPATE STORM ACTIVITY TO PEAK DURING AFTERNOON
HOURS AND PERSIST THROUGH 05Z WEDNESDAY AS UPPER LEVEL DISTURBANCE
MOVES THROUGH THE AREA.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
DRIER AIR WILL FILTER INTO THE DISTRICT BEGINNING THURSDAY...WITH
MORE PREVALENT CLEAR SKIES AND LOWER HUMIDITIES OVER THE WEEKEND.
THE BEST CHANCES FOR RAINFALL THURSDAY AND FRIDAY WILL BE OVER GILA
COUNTY AS SOME RESIDUAL MOISTURE LINGERS OVER HIGHER TERRAIN. WITH
NEAR AVERAGE TEMPERATURES...AFTERNOON RELATIVE HUMIDITY VALUES
FALLING INTO A 25-40 PERCENT RANGE THURSDAY WILL DRY TOWARDS A 10-25
PERCENT RANGE BY THE WEEKEND. OVERNIGHT RECOVERY WILL BE GOOD TO
EXCELLENT. OUTSIDE OF ANY GUSTY THUNDERSTORM WINDS
THURSDAY...TYPICAL LIGHT SUMMER WINDS WILL PREVAIL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FLASH FLOOD WATCH FROM NOON MST TODAY THROUGH WEDNESDAY MORNING
AZZ020>028.
CA...FLASH FLOOD WATCH FROM NOON PDT TODAY THROUGH WEDNESDAY MORNING
CAZ031>033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...MO/HIRSCH
AVIATION....MEYERS
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS TUCSON AZ
910 AM MST TUE AUG 12 2014
.SYNOPSIS...ABUNDANT MOISTURE IN COMBINATION WITH AN UPPER LEVEL
DISTURBANCE WILL PROVIDE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS INTO TONIGHT. SOME STORMS WILL PRODUCE HEAVY RAIN AND
PERHAPS STRONG WINDS. EXPECT SCATTERED THUNDERSTORMS WEDNESDAY
THROUGH THURSDAY FOLLOWED BY A DOWNTURN IN ACTIVITY FRIDAY AND
SATURDAY.
&&
.DISCUSSION...SCATTERED TO NUMEROUS SHOWERS/TSTMS WERE ACROSS
WRN/CENTRAL PIMA COUNTY AND SOUTH CENTRAL PINAL COUNTY AT THIS TIME.
OTHER ISOLATED SHOWERS WERE ACROSS SRN GRAHAM/NRN COCHISE COUNTIES.
ABUNDANT MOISTURE ACROSS SE AZ THIS MORNING WITH DEWPOINTS VALID 16Z
MOSTLY IN THE 60S F. 12/12Z KTWC SOUNDING TOTAL PRECIP WATER WAS
1.76 INCHES...AND THIS VALUE WAS ALMOST TWO STANDARD DEVIATIONS
ABOVE NORMAL.
1453Z BLENDED TOTAL PRECIP WATER IMAGERY INDICATED VALUES RANGING
FROM AROUND 0.75 INCHES ACROSS THE WHITE MOUNTAINS TO NEARLY 2.10
INCHES ACROSS FAR WRN PIMA COUNTY. 12/12Z UPPER AIR PLOTS DEPICTED
593 DM HIGH PRESSURE CENTERED NEAR THE FOUR CORNERS REGION WITH DEEP
TROUGHS OFF THE PACIFIC NW COAST AND OVER THE GREAT LAKES REGION.
LIGHT TO MODERATE SELY FLOW PREVAILED IN THE SURFACE-300 MB LAYER.
VISIBLE SATELLITE IMAGERY DEPICTED A CYCLONIC CIRCULATION SYSTEM
CENTERED JUST NORTH OF HERMOSILLO SONORA MOVING NWWD ACROSS NWRN
SONORA MEXICO. THE FAVORED AREA FOR SHOWERS/TSTMS TO OCCUR THIS
MORNING WILL BE AHEAD OF THIS SYSTEM WEST OF TUCSON. HAVE NOTED THAT
THE 12/14Z RUC HRRR THEN DECREASES COVERAGE OF SHOWERS/TSTMS WEST OF
TUCSON EARLY THIS AFTERNOON. HOWEVER...SCATTERED TO NUMEROUS
SHOWERS/TSTMS ARE THEN PROGGED TO OCCUR FROM THE TUCSON METRO AREA
EWD TO THE NEW MEXICO BORDER BY MID AFTERNOON AND CONTINUING INTO
THIS EVENING.
HOWEVER...THE 12/12Z UNIV OF AZ WRF-NAM WAS SOMEWHAT DIFFERENT
VERSUS THE RUC HRRR. FOR INSTANCE...THE 12/12Z UNIV OF AZ WRF-NAM
DEPICTED WIDESPREAD COVERAGE OF SHOWERS/TSTMS EARLY THIS
AFTERNOON...THEN FAVORED THE AREA FOR SHOWERS/TSTMS GENERALLY FROM
TUCSON WWD/NWWD LATE THIS AFTERNOON AND EARLY THIS EVENING.
AT ANY RATE...THE INHERITED OFFICIAL FORECAST DEPICTS SCATTERED TO
NUMEROUS SHOWERS/TSTMS THIS AFTERNOON/EVENING FOLLOWED BY SCATTERED
SHOWERS AND ISOLATED TSTMS LATE TONIGHT. A FLASH FLOOD WATCH WILL BE
IN EFFECT FROM NOON MST TODAY UNTIL 1 AM MST WED. THE MAIN IMPACT
WILL BE HEAVY RAIN WITH THE POTENTIAL FOR FLASH FLOODING TO OCCUR.
THE STRONGER TSTMS WILL ALSO BE CAPABLE OF PRODUCING STRONG GUSTY
WINDS. HIGH TEMPS TODAY WILL GENERALLY AVERAGE ABOUT 2-5 DEGS F
BELOW NORMAL.
THERE ARE NO UPDATES PLANNED AT THIS TIME. PLEASE REFER TO THE
ADDITIONAL SECTIONS FOR FURTHER DETAIL.
&&
.AVIATION...VALID THRU 13/18Z.
SCATTERED TO NUMEROUS -TSRA/-SHRA MOSTLY WEST OF KTUS THIS MORNING...
THEN SCATTERED TO NUMEROUS TSRA/SHRA AREA-WIDE THIS AFTERNOON AND
THIS EVENING. MVFR VISIBILITIES AND WIND GUSTS TO NEAR 45 KTS WILL
OCCUR WITH THE STRONGER TSRA. SCATTERED -SHRA AND ISOLD -TSRA WILL
THEN PREVAIL LATE TONIGHT INTO WEDNESDAY MORNING. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...DAILY SCATTERED AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS ARE EXPECTED THIS WEEK...WITH A PEAK IN ACTIVITY TODAY
AND TONIGHT. STRONG...GUSTY AND ERRATIC WINDS BETWEEN 35 AND 45 MPH
ARE POSSIBLE WITH STRONGER THUNDERSTORMS. OTHERWISE...WINDS WILL
SHOW NORMAL DIURNAL TRENDS AND LESS THAN 15 MPH.
&&
.PREV DISCUSSION...MAIN IMPULSE SHIFTS INTO NORTHERN ARIZONA LATE
TONIGHT INTO WEDNESDAY ALONG WITH STRONGEST THUNDERSTORM THREAT. WE
WILL PROBABLY BE A LITTLE WORKED OVER WEDNESDAY FOR LESS
COVERAGE...BUT ANY STORMS WE GET WILL BE PRETTY WET. STILL LOOKS
MORE AND MORE LIKE INCREASING POTENTIAL FOR A SECONDARY HIGH CENTER
RECONSOLIDATION REORIENTING THE RIDGE INTO A PARTIAL BLOCKING
POSITION FRIDAY AND SATURDAY. A COUPLE OF DOWN DAYS TO END THE WEEK.
WE SHOULD BOUNCE BACK TOWARD AN AVERAGE DAY BY SUNDAY OR MONDAY AS
THE RIDGE AMPLIFIES NORTH OF US.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM NOON MST TODAY UNTIL 1 AM MST WEDNESDAY
FOR AZZ501>515.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
DISCUSSION...FRANCIS
AVIATION/FIRE WEATHER...HUMPHREYS
PREVIOUS DISCUSSION...MEYER
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
330 PM MDT TUE AUG 12 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 330 PM MDT TUE AUG 12 2014
FOR TONIGHT...OVERALL THE AIRMASS WILL REMAIN DRY AND SUBSIDENT
WITH THE UPPER LEVEL RIDGE OVERHEAD. THERE WILL BE ENOUGH MOISTURE
IN THE MOUNTAINS FOR A FEW EVENING THUNDERSTORMS...BUT COVERAGE
WILL BE LIMITED AND THE DURATION SHORT LIVED. THE HRRR SHOWS VERY
LIMITED DEVELOPMENT IN AND AROUND SUMMIT AND PARK COUNTIES BUT
DRY ELSEWHERE. ON WEDNESDAY...THE RIDGE IS PROGGED TO SHIFT TO THE
EAST WITH THE FLOW ALOFT BECOMING SOUTHWESTERLY. SUBTROPICAL
MOISTURE WILL INCREASE OVER WESTERN COLORADO AHEAD OF AN
APPROACHING UPPER LEVEL DISTURBANCE FM THE DESERT SOUTHWEST. THE
COVERAGE OF TSTMS WILL INCREASE IN THE MOUNTAINS AND PRECIPITABLE
WATER VALUES ARE PROGGED TO INCREASE AS WELL. BY LATE AFTN...SOME
OF TSTMS WILL START TO SPREAD INTO THE URBAN CORRIDOR. STORM
MOTIONS IN THE HIGH COUNTRY WEDNESDAY AFTN WILL BE SSW AROUND 15
KTS. ACROSS THE URBAN CORRIDOR AND ADJACENT PLAINS...SELY WINDS
WILL INCREASE IN THE AFTN...STG ENOUGH TO INDUCE A WEAK DENVER
CYCLONE. AS A RESULT...WL GO WITH A SLGT CHC OF TSTMS IN THE
AFTERNOON. CAPES AT KDEN IN THE 350-450MB RANGE BY 00Z THURSDAY
WITH PW VALUES CLOSE TO ONE INCH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 PM MDT TUE AUG 12 2014
THE NEXT WEEK WILL SEE CONTINUED RIDGING OVER THE SOUTHWESTERN
U.S. BUT WITH A SIGNIFICANT SURGE OF MONSOONAL MOISTURE ACROSS
COLORADO FOR THE LATTER HALF OF THIS WEEK. MOUNTAIN AREAS ARE
GOING TO SEE MOST OF THE PRECIPITATION FROM THE MONSOONAL
MOISTURE...BUT THE PLAINS WILL NOT BE IMMUNE TO THE RAINFALL. THE
WESTERN SLOPE SHOULD SEE THE ARRIVAL OF THE DEEPER MOISTURE BY
WEDNESDAY AFTERNOON...BUT COMPUTER MODELS ARE SHOWING A SHORT WAVE
TROUGH MOVING THROUGH THE UPPER RIDGE ON THURSDAY WHICH IS GOING
TO ORGANIZE AND SUSTAIN MOUNTAINS CONVECTION THROUGH THE DAY AND
ONTO THE PLAINS THURSDAY EVENING. ANOTHER ROUND OF AFTERNOON
SHOWERS IS EXPECTED ON FRIDAY AS ABUNDANT MONSOONAL MOISTURE
REMAINS OVER THE STATE AND UPPER LEVEL HEIGHTS BEGIN RISING. THE
REST OF THE WEEKEND WILL CONTINUE WITH MODERATE RIDGING ALOFT AND
A CONTINUED INTRUSION OF MONSOONAL MOISTURE UNDER THE RIDGE. FLOW
ALOFT WILL BE LIGHT TO MODERATE AND OUT OF THE WEST...MAKING IT
POSSIBLE FOR STORMS TO BE SLOW-MOVING AND CAPABLE OF PRODUCING
LOCALLY HEAVY RAINS. NO CHANGE IN THE UPPER LEVEL FLOW PATTERN
EXPECTED BEFORE THE MIDDLE OF NEXT WEEK. IN FACT...THE ECMWF IS
SHOWING ANOTHER MONSOONAL SURGE ARRIVING NEXT TUESDAY. UNTIL THEN
TEMPERATURES WILL BE AROUND SEASONAL NORMALS WITH A CHANCE OF
AFTERNOON SHOWERS EACH DAY.
&&
.AVIATION...(FOR THE TAFS THROUGH 00Z WEDNESDAY LATE AFTERNOON)
ISSUED AT 330 PM MDT TUE AUG 12 2014
NO CIG/VSBY RESTRICTIONS ANTICIPATED THROUGH 00Z THURSDAY. AMS TOO
DRY AND SUBSIDENT IN THE MID LEVELS FOR TSTMS THIS AFTN AND
EVENING. DIURNAL WIND PATTERN WITH TYPICAL DRAINAGE WINDS THROUGH
18Z WEDNESDAY. AFT 18Z WEDNESDAY...SELY WINDS WILL INCREASE IN
THE AFTN SO SHOULD BE SUFFICIENT ENOUGH TO PRODUCE A WEAK DENVER
CYCLONE. ENOUGH MOISTURE AND INSTABILITY IN THE AFTN TO MENTION
VCTSIN WEDNESDAY AFTN...PROBABLY AFTER 21-22Z. COULD SEE BKN
CIGS AOA 080FT AGL BY LATE THU AFTN/EVNG...AS MID LEVEL MOISTURE
INCREASES FM THE SOUTHWEST.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COOPER
LONG TERM...DANKERS
AVIATION...COOPER
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
320 PM EDT Tue Aug 12 2014
.Near Term [Through Tonight]...
A cold front continues to trek across the southeastern CONUS
today, with a convective boundary just east of AAF to FZG. This
is bringing scattered showers and thunderstorms to the area once
again. The HRRR is handling our atmospheric conditions pretty well
so far today, so adjusted PoPs toward recent runs. Coverage will
be highest in southeast Alabama, southwest Georgia, and over the
coastal waters. Some of these storms will last into the early
overnight hours, particularly near the AL-FL border. Showers over
our eastern coastal waters will likely generate once again in the
early hours of Wednesday morning. Highs today will be in the low-
mid 90s, around 90 along the coast, and lows tonight will be in
the low to mid 70s, with temperatures cooling the most in
southeast Alabama.
.Short Term [Wednesday Through Thursday Night]...
A surface cold front will slowly push southeast by tomorrow,
likely reaching the northern and northwest parts of our forecast
area. The front will not represent a significant transition in
surface temperatures as it stalls in the northern part of our area
in the next 24-36 hours, but there will be a fairly substantial
precipitable water and low-level dewpoint gradient across the
boundary. Behind the front, PWATs should fall to around 1.5 inches
by Thursday afternoon which is below the 20th percentile for
August at TLH. Ahead of the front, PWATs should remain above 2
inches which is slightly above normal. This configuration should
limit rain chances in the northern and northwest parts of our
forecast area both Wednesday and Thursday. However, showers and
storms will be likely in the southeastern part of our area,
especially closer to the Suwannee River. Both high-resolution and
global models suggest a continuation of the recent convective
timing: thunderstorms quickly develop and expand in coverage
offshore in the 06-12Z timeframe, and then affect the coastal
areas and the Florida Big Bend in the morning hours, with more
scattered development in the afternoon elsewhere. We followed this
trend in our forecast. Highs may be limited in the coastal areas
and the Florida Big Bend where early cloud cover and rain is more
likely. Elsewhere mid-90s seem likely inland.
There will be the potential for locally heavy rainfall and
isolated flooding during the period - mainly in the Florida Big
Bend and especially in the Taylor, Dixie, and Lafayette County
area. KTLH radar has already indicated 2-4" of rain in much of
those counties since Monday morning, with convection-allowing
models indicating isolated additional rainfall of upwards of 5"
will be possible by Wednesday evening. More on this in the
hydrology section.
.Long Term [Friday Through Tuesday]...
A drier air mass should continue to advect into the area for
Friday and Saturday, which should reduce rain chances over much of
our forecast area except for perhaps the far southeast corner.
PWAT values are then forecast to increase again from Sunday into
early next week to more normal levels as deeper southwest flow
sets up. Temperatures should be relatively close to normal.
&&
.Aviation...
[Through 18Z Wednesday] Scattered to numerous convection is
expected to develop once again this afternoon and coverage is
more than sufficient to warrant an explicit mention in the TAFs.
VFR will prevail for the most part, with the exception of drops to
MVFR for storms near the terminals.
&&
.Marine...
Showers and thunderstorms should be fairly widespread across the
coastal waters for the next several mornings ahead of a stalling
cold front just to the north. Winds and seas may be higher near
storms. Through Wednesday evening, winds of 10-15 knots should
create widespread 2-3 foot seas. Weaker winds thereafter will
promote seas of 2 feet or less.
&&
.Fire Weather...
Despite a drier airmass moving into the region this week, relative
humidity values will remain above critical thresholds. Red flag
criteria will not be met.
&&
.Hydrology...
There will be a chance for some isolated flooding in the Florida
Big Bend in the next couple days - particularly in Dixie, Taylor,
and Lafayette Counties. Radar estimates indicate that 2-4 inches
of rain has fallen across much of those counties since Monday
morning. While average rain totals through Thursday should be on
the order of 2-3 inches, isolated amounts at least double that
could contribute to localized areas of flooding. Elsewhere, slow-
moving storms and a moist atmosphere mean that flooding can`t be
ruled out in the remainder of the Florida Panhandle and Big Bend,
as well as extreme southern Georgia. However, localized flooding
is less likely in those areas.
Any flooding would likely be confined to urban areas, low-lying
spots, or smaller basins and streams (if it occurs).
&&
.Preliminary Point Temps/PoPs...
Tallahassee 74 93 74 95 73 / 30 60 20 40 20
Panama City 79 91 77 91 76 / 30 40 20 30 20
Dothan 72 94 71 94 71 / 30 30 20 20 10
Albany 73 94 71 94 70 / 30 30 20 20 10
Valdosta 73 95 72 95 72 / 30 60 20 40 20
Cross City 75 91 74 91 73 / 40 60 20 60 30
Apalachicola 78 90 77 90 76 / 30 60 20 40 20
&&
.TAE Watches/Warnings/Advisories...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...MOORE
SHORT TERM...LAMERS
LONG TERM...LAMERS
AVIATION...MOORE
MARINE...LAMERS
FIRE WEATHER...MOORE
HYDROLOGY...LAMERS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
227 PM MDT TUE AUG 12 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 152 PM MDT TUE AUG 12 2014
A RIDGE WILL BE OVER THE ROCKIES TONIGHT AND A SURFACE TROUGH OVER
EASTERN COLORADO. SOME SCATTERED CUMULUS HAVE DEVELOPED OVER
EASTERN COLORADO. CURRENT RADAR WITH NO RETURNS. THE HRRR AND NAM
BOTH DO NOT INDICATE STORMS FOR THIS EVENING AND THAT SEEMS
REASONABLE BASED ON VERY DRY FORECAST SOUNDINGS OVER THE AREA.
ALSO WATER VAPOR IMAGERY SHOWING STRONG SUBSIDENCE EAST OF THE
CENTRAL ROCKIES. POPS WILL BE NIL TONIGHT AND AGAIN ON WEDNESDAY
AS SUBSIDENCE CONTINUES. LOW TEMPERATURES TONIGHT WILL BE IN THE
LOWER 60S AND MAX TEMPERATURES WEDNESDAY AROUND 90.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 152 PM MDT TUE AUG 12 2014
A DRY FORECAST CONTINUES THROUGH WEDNESDAY NIGHT AND EARLY THURSDAY
AS THE RIDGE AND SUBSIDENCE CONTINUES OVER THE HIGH PLAINS. BY
THURSDAY AFTERNOON THE RIDGE BREAKS DOWN SOME AS A SHORTWAVES
MOVES INTO THE AREA. THIS SHORTWAVE WILL CONTINUE MOVING ACROSS
THE FA THURSDAY NIGHT INTO FRIDAY MORNING. STORMS SHOULD INITIATE
ON A SURFACE TROUGH IN EASTERN COLORADO THURSDAY AFTERNOON AND
THEN SPREAD EAST ACROSS THE REST OF THE FA THURSDAY NIGHT. CHANCE
POPS LOOK GOOD FOR THIS EVENT. STORMS WILL LIKELY LINGER IN THE
EASTERN FA EARLY FRIDAY MORNING WITH SUBSIDENCE MOVING INTO THE FA
FROM WEST TO EAST. CONFIDENCE IS NOT HIGH FOR STORMS FRIDAY
AFTERNOON BUT CANNOT RULE OUT AT LEAST AN ISOLATED STORM OR TWO SO
WILL LOWER POPS TO SLIGHT CHANCE.
IN THE EXTENDED...FROM FRIDAY NIGHT THROUGH TUESDAY...A BROAD
RIDGE WILL BE OVER THE WESTERN CONUS EXTENDING INTO THE HIGH
PLAINS. NUMEROUS WEAK DISTURBANCES WILL MOVE THROUGH THE RIDGE
INTO THE HIGH PLAINS. THIS WILL PROVIDE POTENTIAL FOR STORMS EACH
AFTERNOON AND EVENING ACROSS THE FA THROUGH TUESDAY. CONSEQUENTLY, PLAN
TO HAVE AT LEAST A SLIGHT CHANCE OF STORMS EACH DAY. MAX
TEMPERATURES WILL REACH THE LOWER 90S EACH DAY. MIN TEMPERATURES
WILL BE IN THE LOWER TO MID 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1046 AM MDT TUE AUG 12 2014
VFR CONDITIONS WILL CONTINUE AT KGLD AND KMCK FOR THE NEXT 24
HOURS. A WEAK SHORTWAVE PROGGED TO MOVE ACROSS THE AREA OVERNIGHT
WILL HAVE SOME MID LEVEL CLOUDS ASSOCIATED WITH IT BUT NO
PRECIPITATION. WINDS WILL BE LIGHT FROM THE SOUTHEAST IN RESPONSE
TO RETREATING HIGH PRESSURE AND A SURFACE TROUGH IN EASTERN COLORADO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...FS
LONG TERM...FS
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1055 AM MDT TUE AUG 12 2014
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 235 AM MDT TUE AUG 12 2014
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW HIGHLY AMPLIFIED
RIDGE CENTERED OVER THE CENTRAL ROCKIES EXTENDING WELL INTO THE
CANADIAN ROCKIES. THE EASTERN EXTENT OF THIS RIDGE HAS SHIFTED OVER
OUR CWA...WITH THE MAIN STORM TRACK NOW WELL EAST. MONSOONAL PLUME
IS ALSO ORIENTATED MORE OVER THE GREAT BASIN THAT CENTRAL ROCKIES
WITH LITTLE IN THE WAY OF UPSTREAM ACTIVITY OVER THE NORTHERN PLAINS.
AT THE SURFACE HIGH PRESSURE REMAINS IN PLACE THE CENTRAL AND HIGH
PLAINS.
WITH H5 RIDGE NOW HOLDING MUCH MORE INFLUENCE ON WX OVER OUR
CWA...DRY CONDITIONS SHOULD CONTINUE THROUGH AT LEAST WEDNESDAY
AFTERNOON. GUIDANCE HAS SHIFTED TRACK OF A WEAK SHORTWAVE WEDNESDAY
NIGHT TOWARDS THE NORTHERN PLAINS...WITH EVEN THE SOUTHERNMOST
REFLECTION OF THIS BARELY INFLUENCING SW NEBRASKA. WITH THE PRECIP
SIGNAL SHIFTED NORTH AND A VERY DRY AIR MASS IN PLACE (ON ALL
AVAILABLE GUIDANCE) I REMOVED THUNDERSTORM MENTION FROM WEDNESDAY
NIGHT. BY THURSDAY A STRONGER SHORTWAVE WILL BEGIN TO BREAKDOWN THE
WESTERN PART OF THE RIDGE ALLOWING BETTER FORCING TO MOVE TOWARDS
THE PLAINS...AND WITH AT LEAST MODERATE INSTABILITY AND SHEER IN
PLACE WE COULD START TO SEE THUNDERSTORM INITIATION BY THURSDAY
AFTERNOON IN THE WEST. THE BEST CHANCES WILL HOLD OFF UNTIL THURSDAY
NIGHT WHEN BETTER FORCING WILL BE IN PLACE.
TEMPERATURES SHOULD RETURN TO SEASONAL VALUES IN THE UPPER 80S
TODAY...WITH CONTINUED WARMING THROUGH THURSDAY. THE WARMEST DAY
THIS WEEK WILL LIKELY BE ON THURSDAY WHEN GOOD SOUTHERLY FLOW WILL
SUPPORT TEMPERATURES AT LEAST IN THE MIDDLE 90S. GUIDANCE IS SHOWING
H85 TEMPS AROUND 30C WHICH WITH GOOD MIXING (LITTLE CLOUD COVER) MAY
SUPPORT TEMPS IN THE UPPER 90S/NEAR 100F.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 235 AM MDT TUE AUG 12 2014
NO SIGNIFICANT CHANGES WERE NEEDED IN THE EXTENDED. THE BIGGEST
CHALLENGE WILL CONTINUE TO BE TIMING OF BEST PRECIPITATION CHANCES.
MEDIUM RANGE GUIDANCE SHOWS A WEST/NORTHWESTERLY UPPER FLOW REGIME
WITH PERIODIC SHORTWAVE TROUGHS PASSING THROUGH. ONE WAVE WILL MOVE
EASTWARD THROUGH THE CENTRAL HIGH PLAINS ON FRIDAY BRINGING
SLIGHT/LOW CHANCE POPS TO THE ENTIRE FORECAST AREA. BEYOND
FRIDAY...GFS IS MORE PROGRESSIVE THAN ECMWF AND GFS ENSEMBLE SPREAD
GROWS. GIVEN DIFFERENCES IN THE MODELS TYPICAL OF THIS TYPE PATTERN
WITH TRANSIENT WEAK SHORTWAVES DID NOT TRY TO SEPARATE OUT BEST
CHANCES AND ACCEPTED THE MEDIUM RANGE CONSENSUS BLEND FOR POPS THIS
WEEKEND INTO EARLY NEXT WEEK. TEMPERATURES SHOULD BE SLIGHTLY ABOVE
NORMAL THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1046 AM MDT TUE AUG 12 2014
VFR CONDIITONS WILL CONTINUE AT KGLD AND KMCK FOR THE NEXT 24
HOURS. A WEAK SHORTWAVE PROGGED TO MOVE ACROSS THE AREA OVERNIGHT
WILL HAVE SOME MID LEVEL CLOUDS ASSOCIATED WITH IT BUT NO
PRECIPITATION. WINDS WILL BE LIGHT FROM THE SOUTHEAST IN RESPONSE
TO RETREATING HIGH PRESSURE AND A SURFACE TROUGH IN EASTERN COLORADO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BRB
AVIATION...FS
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1245 PM CDT TUE AUG 12 2014
.AVIATION...
FOR THE 12/18Z TAFS...VFR CONDITIONS TO DOMINATE THE TAF PERIOD
WITH SOMEWHAT COOLER AND DRIER AIR MASS COMPARED TO PREVIOUS DAYS.
FRONT RESPONSIBLE FOR THIS CHANGE HAS SLIPPED JUST SOUTH OF OUR
REGION BUT STILL MAY HELP GENERATE SOME SPOTTY CONVECTION NEAR OR
JUST SOUTH OF THE LFK TERMINAL THIS AFTERNOON...HAVE NOT INCLUDED
VCTS AT LFK FOR THIS ISSUANCE DUE TO LOW CONFIDENCE ANYTHING WILL
DEVELOP THAT FAR NORTH. OTHERWISE...EXPECT LIGHT NLY WINDS TO
PREVAIL THIS AFTERNOON AND BECOMING NEAR CALM OVERNIGHT WITH SOME
PATCHY FOG POSSIBLE AT ELD/MLU. CU FIELD WILL REDEVELOP LATE IN
THE TAF PERIOD SIMILAR TO THIS AFTERNOON WITH HEIGHTS BETWEEN
4-5KFT. WINDS WILL SHIFT MORE E/NE BY 13/15Z INCREASE TO 5-10 KTS.
/19/
&&
.PREV DISCUSSION... /ISSUED 1115 AM CDT TUE AUG 12 2014/
DISCUSSION...
THE 15Z SFC ANALYSIS INDICATES THAT THE WEAK COOL FRONT IS A
LITTLE ILL-DEFINED LATE THIS MORNING...AND EXTENDS FROM DEEP E TX
INTO NCNTRL LA AND CNTRL MS. HOWEVER...THE DRIER AIR DOES LAG THE
FRONT FARTHER N ACROSS EXTREME NE TX/SW AR...BUT SHOULD GRADUALLY
SEEP S ACROSS THE REMAINDER OF THE AREA THIS AFTERNOON. HAVE
ALREADY SEEN MID AND UPPER LEVEL DRY AIR INFILTRATE S ACROSS AT
LEAST THE NRN HALF OF THE AREA...EVIDENCED FROM THE 12Z KSHV
RAOB...WITH PW/S STILL NEAR OR IN EXCESS OF 2 INCHES FARTHER S
WITHIN THE MOIST SECTOR /PER THE 12Z KLCH RAOB/. ALREADY SEEING
MODERATE MLCAPES DEVELOPING NOW NEAR AND S OF I-20 ACROSS E TX/N
LA ALONG/JUST AHEAD OF THE DRIER SFC AIR...WITH EVEN A FEW
TOWERING CU ON VISIBLE SATELLITE OVER PORTIONS OF ECNTRL TX WHERE
TEMPS ARE NEARING 90 DEGREES ATTM. GIVEN THE AVAILABLE MOISTURE
STILL AVAILABLE THIS AFTERNOON...AND STRONG HEATING...CAN/T RULE
OUT ISOLATED CONVECTION DEVELOPING BY EARLY AFTERNOON OVER DEEP E
TX/NCNTRL LA S OF I-20 AS INDICATED FROM THE LATEST HRRR RUN AND
THE 12Z WRF.
HAVE ADDED SLIGHT CHANCE POPS FARTHER W ACROSS THE REMAINDER OF
NCNTRL LA/DEEP E TX IN THE ZONE UPDATE...WITH ANY CONVECTION
DIMINISHING OVER THE AREAS BY LATE AFTERNOON AS THE DRIER AIR
CONTINUES TO FILTER S. THE 12Z WRF REMAINS CONSISTENT AND BEST IN
HANDLING THE CURRENT DEWPOINTS/DRY AIR ADVECTION...WITH THE ERN
MOST ZONES A LITTLE LATER WITH THE DRY AIR ARRIVING GIVEN THE
WEAKER PRESSURE GRADIENT. TEMPS ALONG/S OF THE I-20 CORRIDOR HAVE
WARMED QUICKLY THIS MORNING...WITH 16Z TEMPS NOW NEARING 90
DEGREES. HAVE BUMPED UP MAX TEMPS A COUPLE DEGREES THIS AFTERNOON
AS READINGS SHOULD LEVEL OFF WITH THE ARRIVAL OF THE DRIER AIR.
OTHERWISE...THE REMAINDER OF THE FORECAST IS ON TRACK.
ZONE UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 92 67 90 67 91 / 10 0 10 10 10
MLU 91 66 88 64 89 / 10 0 10 10 10
DEQ 88 61 88 62 88 / 0 0 10 10 10
TXK 89 64 86 64 88 / 0 0 10 10 10
ELD 89 63 88 62 88 / 0 0 10 10 10
TYR 95 65 89 67 91 / 10 0 10 10 10
GGG 93 65 89 65 91 / 10 0 10 10 10
LFK 95 68 93 69 95 / 20 10 10 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
19
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1115 AM CDT TUE AUG 12 2014
.DISCUSSION...
THE 15Z SFC ANALYSIS INDICATES THAT THE WEAK COOL FRONT IS A
LITTLE ILL-DEFINED LATE THIS MORNING...AND EXTENDS FROM DEEP E TX
INTO NCNTRL LA AND CNTRL MS. HOWEVER...THE DRIER AIR DOES LAG THE
FRONT FARTHER N ACROSS EXTREME NE TX/SW AR...BUT SHOULD GRADUALLY
SEEP S ACROSS THE REMAINDER OF THE AREA THIS AFTERNOON. HAVE
ALREADY SEEN MID AND UPPER LEVEL DRY AIR INFILTRATE S ACROSS AT
LEAST THE NRN HALF OF THE AREA...EVIDENCED FROM THE 12Z KSHV
RAOB...WITH PW/S STILL NEAR OR IN EXCESS OF 2 INCHES FARTHER S
WITHIN THE MOIST SECTOR /PER THE 12Z KLCH RAOB/. ALREADY SEEING
MODERATE MLCAPES DEVELOPING NOW NEAR AND S OF I-20 ACROSS E TX/N
LA ALONG/JUST AHEAD OF THE DRIER SFC AIR...WITH EVEN A FEW
TOWERING CU ON VISIBLE SATELLITE OVER PORTIONS OF ECNTRL TX WHERE
TEMPS ARE NEARING 90 DEGREES ATTM. GIVEN THE AVAILABLE MOISTURE
STILL AVAILABLE THIS AFTERNOON...AND STRONG HEATING...CAN/T RULE
OUT ISOLATED CONVECTION DEVELOPING BY EARLY AFTERNOON OVER DEEP E
TX/NCNTRL LA S OF I-20 AS INDICATED FROM THE LATEST HRRR RUN AND
THE 12Z WRF.
HAVE ADDED SLIGHT CHANCE POPS FARTHER W ACROSS THE REMAINDER OF
NCNTRL LA/DEEP E TX IN THE ZONE UPDATE...WITH ANY CONVECTION
DIMINISHING OVER THE AREAS BY LATE AFTERNOON AS THE DRIER AIR
CONTINUES TO FILTER S. THE 12Z WRF REMAINS CONSISTENT AND BEST IN
HANDLING THE CURRENT DEWPOINTS/DRY AIR ADVECTION...WITH THE ERN
MOST ZONES A LITTLE LATER WITH THE DRY AIR ARRIVING GIVEN THE
WEAKER PRESSURE GRADIENT. TEMPS ALONG/S OF THE I-20 CORRIDOR HAVE
WARMED QUICKLY THIS MORNING...WITH 16Z TEMPS NOW NEARING 90
DEGREES. HAVE BUMPED UP MAX TEMPS A COUPLE DEGREES THIS AFTERNOON
AS READINGS SHOULD LEVEL OFF WITH THE ARRIVAL OF THE DRIER AIR.
OTHERWISE...THE REMAINDER OF THE FORECAST IS ON TRACK.
ZONE UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 92 67 90 67 91 / 10 0 10 10 10
MLU 91 66 88 64 89 / 10 0 10 10 10
DEQ 88 61 88 62 88 / 0 0 10 10 10
TXK 89 64 86 64 88 / 0 0 10 10 10
ELD 89 63 88 62 88 / 0 0 10 10 10
TYR 95 65 89 67 91 / 10 0 10 10 10
GGG 93 65 89 65 91 / 10 0 10 10 10
LFK 95 68 93 69 95 / 20 10 10 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
15
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
403 PM EDT TUE AUG 12 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT TUE AUG 12 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW JUST
EAST OF THE SAULT RESULTING IN NNW FLOW FROM NW ONTARIO THROUGH THE
WRN GREAT LAKES. THE BACK EDGE OF THE CLOUDS ASSOCIATED WITH THE LOW
HAD MOVED TO NEAR SAW-IMT LEAVING CLEAR SKIES OVER THE WEST AND
THICK CLOUDS WITH A FEW SPRINKLES OVER THE ERN CWA. AN UPSTREAM
CLIPPER SHORTWAVE TROUGH AND COLD FRONT THAT SUPPORTED A FEW LIGHT
SHOWERS OR SPRINKLES WAS MOVING THROUGH NW ONTARIO.
TONIGHT...EXPECT THAT SOME LIGHT SHOWERS OR SPRINKLES ASSOCIATED
WITH THE NW ONTARIO SHRTWV MAY MOVE INTO WRN LAKE SUPERIOR AND
POSSIBLY WRN UPPER MI. HOWEVER...SINCE FORCING WITH THE SHRTWV IS
WEAK AND LITTLE MOISTURE/INSTABILITY IS AVAILABLE DURING THE
OVERNIGHT...NO PCPN MENTION WAS ADDED TO THE FCST.
WED...BEHIND THE COLD FRONT...NNW WINDS WILL AGAIN INCREASE WHICH
COULD SUPPORT AN INCREASE IN UPSLOPE CLOUDS OVER N CNTRL UPPER MI.
TEMPS WILL REMAIN BELOW NORMAL WITH HIGHS FROM THE MID 60S NORTH TO
THE LOWER 70S SOUTH. SWIM RISK WILL AGAIN BE HIGH AS 3 TO 5 FOOT
WAVES ARE EXPECTED INTO MARQUETTE AND ALGER COUNTIES BY AFTERNOON.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 328 PM EDT TUE AUG 12 2014
MAIN FCST CONCERNS IN THE MEDIUM/LONGER RANGE WL FOCUS ON EXPECTED
BLO NORMAL TEMPS FOR WED THRU THU...WHEN DRY CNDN HI PRES IS FCST TO
DOMINATE UNDER A CONFLUENT NNW FLOW ALF. FOCUS FOR FRI/SAT WL SHIFT
TO PCPN CHCS ASSOCIATED WITH THE INTERACTION BTWN RETURNING MSTR IN
THE LLVL SW FLOW ARND THE DEPARTING HI TO THE SE AND SHRTWVS
TRACKING THRU THE GREAT LKS WITHIN THE NW FLOW FARTHER ALF. ALTHOUGH
ABV NORMAL TEMPS MAY RETURN FOR FRI INTO SAT...NO SUMMER-LIKE WARMTH
IS EXPECTED DURING THE NEXT WEEK.
WED NGT/THU...HI PRES AND DRY AIRMASS WITH PWAT BTWN 0.25-0.50 INCH
/AS LITTLE AS ABOUT 25 PCT OF NORMAL/ WL PASS OVER UPR MI UNDER NNW
FLOW ALF TO THE W OF SLOW MOVING CLOSED LO NEAR THE ONTARIO/QUEBEC
BORDER. UNDER MOCLR SKIES...EXPECT THE LOWEST MIN TEMPS ON WED NGT
OVER THE INTERIOR W...WHERE WINDS WL BE LIGHTEST FOR A LONGER TIME
AND WHERE THE RDG AXIS IS FCST TO BE AT 12Z THU. NOT OUT OF THE
QUESTION THERE COULD BE SOME 30S AT THE COLDER LOCATIONS IN THIS
AREA. WITH H85 TEMPS FCST TO PEAK BTWN 8C OVER THE E AND 12C OVER
THE W AT 00Z FRI...EXPECT HI TEMPS TO REACH THE 70S OVER THE
INTERIOR W/SCENTRAL BUT HOLD IN THE 60S OVER MUCH OF THE E WITH A
STEADY NNW SFC-H925 FLOW OFF LK SUP.
THU NGT...SFC HI PRES IS FCST TO SINK OVER INDIANA BY 12Z FRI...
WITH SFC RDG AXIS EXTENDING N THRU ERN UPR MI. THE LOWEST TEMPS WL
BE OVER THE INTERIOR E...WHERE PWAT UNDER 0.5 INCH/MOCLR SKIES/
LIGHTER WINDS UNDER THE RDG AXIS WL LINGER THRU THE NGT. SOME CLDS
ASSOCIATED WITH PWAT RISING AOA 1 INCH AT IWD BY 12Z FRI IN SW
RETURN FLOW ARND THE SFC HI WL LIMIT THE DIURNAL TEMP FALL IN THAT
AREA.
FRI THRU SAT...UPR MI IS FCST TO REMAIN UNDER NW FLOW ALF BTWN DEEP
UPR TROF OVER QUEBEC AND RDG EXTENDING THRU THE PLAINS. THE
INTERACTION BTWN SHRTWVS DIGGING SEWD THRU THIS UPR FLOW AND MORE
MSTR ADVECTED INTO THE AREA IN LLVL WSW FLOW TO THE NW OF SFC HI
FCST TO SINK INTO THE SRN MID ATLANTIC STATES WL BE THE MAIN FCST
CONCERN DURING THIS PERIOD. A GOOD NUMBER OF THE MEDIUM RANGE MODELS
GENERATE PCPN AS EARLY AS FRI...WHEN THE HIER PWAT ARND 1.5 INCHES
IS FCST TO RETURN. CONSIDERING THE RATHER DRAMATIC INCRS IN PWAT/
SOME ISENTROPIC ASCENT...ADDED CHC POPS FOR THE FRI FCST DESPITE AN
ABSENCE OF SGNFT DEEP LYR QVECTOR CNVGC WELL SE OF STRONGER SHRTWV
SLIDING THRU NW ONTARIO. A BETTER CHC OF SHOWERS/A FEW TS WL ARRIVE
ON FRI NGT AND SAT...WHEN MODEL CONSENSUS IS TRENDING TOWARD THE
PASSAGE OF THE DIGGING ONTARIO SHRTWV/ATTENDANT SFC COLD FNT AND AN
AREA OF SHARPER DEEP LYR QVECTOR CNVGC. ALTHOUGH THE GREATER CLD
COVER WL TEND TO LIMIT THE DIURNAL DIURNAL VARIATION DURING THIS
TIME...EXPECT TEMPS TO RISE ABV NORMAL DURING THIS PERIOD AS THE WSW
FLOW BRINGS A RETURN OF H85 TEMPS AS HI AS 16-17C BY SAT.
SUN THRU TUE...MOST OF THE LONGER RANGE MODELS INDICATE SFC HI PRES
WL BLD INTO THE UPR LKS ON SUN FOLLOWING SHRTWV/COLD FROPA PASSAGE
BY LATE SAT...SO CONSENSUS FCST WL SHOW A DRYING TREND AND A RETURN
OF A BIT COOLER AIR. PCPN CHCS WL RETURN EARLY NEXT WEEK AS THE UPR
FLOW IS FCST TO BECOME MORE ZONAL AND ALLOW THE PASSAGE OF ANOTHER
SHRTWV.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 134 PM EDT TUE AUG 12 2014
HIGH PRESSURE AND DRY AIR MOVING INTO THE WESTERN U.P. WILL BRING
VFR CONDITIONS TO BOTH KIWD THROUGH THE FCST PERIOD. MVFR CONDITIONS
IN COOL MOIST UPSLOPE FLOW OFF OF LAKE SUPERIOR WILL GIVE WAY TO VFR
CIGS BY LATE AFTERNOON AS DRY AIR SLOWLY EDGES INTO CNTRL UPPER MI.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 402 PM EDT TUE AUG 12 2014
NORTH WINDS GUSTING TO MORE THAN 25 KTS ACROSS THE EASTERN PART OF
THE LAKE WILL DIMINISH THIS EVENING AS THE PRES GRADIENT WEAKENS. A
REINFORCING COLD FRONT WILL PUSH ACROSS THE LAKE ON WEDNESDAY
ALLOWING NORTHWESTERLY WIND GUSTS OF UP TO 25 KTS WEDNESDAY
AFTERNOON. WINDS SHOULD DIMINISH BY LATE WEDNESDAY AND THEN REMAIN
BELOW 15 KTS INTO THE UPCOMING WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
BEACH HAZARDS STATEMENT UNTIL 10 PM EDT THIS EVENING FOR MIZ005-
006.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1251 PM EDT TUE AUG 12 2014
.AVIATION...
//DISCUSSION...
BLOSSOMING AREA OF SHOWERS AND EMBEDDED THUNDERSTORMS AS WE ENTER
PEAK HEATING OF THE DAY AND UPPER LEVEL TROUGH AXIS MOVES OVERHEAD.
MAJORITY OF ACTIVITY SHOULD BE EXITING/DIMINISHING AROUND 00Z.
SURFACE NORTHWEST WINDS AROUND 10 KNOTS WILL ATTEMPT TO USHER IN
DRIER AIR...BUT IT WILL TAKE MOST/ALL OF THE NIGHT-TIME HOURS TO
SCOUR OUT THE LOW CLOUDS (HIGH IFR/LOW MVFR). ANY RESIDUAL LOW
CLOUDS WEDNESDAY MORNING SHOULD MIX OUT AND LIFT.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILINGS BELOW 5000 FEET THROUGH TONIGHT.
* MEDIUM CONFIDENCE IN THUNDERSTORM THIS AFTERNOON.
&&
.PREV DISCUSSION...ISSUED 827 AM EDT TUE AUG 12 2014
UPDATE...
PLENTY OF LOW LEVEL MOISTURE LEFTOVER ACROSS SOUTHEAST MICHIGAN AS
SURFACE DEW POINTS HOVER IN THE LOW TO MID 60S...AND UPPER LEVEL
TROUGH/COLD POOL (500 MB TEMPS OF -13 TO -14 C) AND SECONDARY
SURFACE COLD FRONT SWINGING THROUGH TODAY WILL BE SUFFICIENT TO
GENERATE NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS...AS THERE
IS ALSO SOLID INSTABILITY WITH SBCAPES IN THE 1000-1500 J/KG
RANGE. 0-6 KM SHEAR REACHES AROUND 20 KNOTS TOWARD THE CANADIAN
BORDER...OTHERWISE SHEAR IS WEAK...AND THUS SEVERE WEATHER IS NOT
EXPECTED. COULD SEE SMALL HAIL AND BRIEF HEAVY RAIN.
PREV DISCUSSION...ISSUED 305 AM EDT TUE AUG 12 2014
SHORT TERM...TODAY AND TONIGHT
HIGH AMPLITUDE MID LEVEL TROUGH NOW SHIFTING ACROSS THE UPPER
MISSISSIPPI VALLEY WILL STEADILY DEEPEN AND EVENTUALLY CLOSE OFF
HEADING INTO TODAY AS IT PIVOTS ACROSS THE LOWER PENINSULA. LEAD
SPOKE OF VORTICITY ANCHORING THE EDGE OF THE MAIN HEIGHT FALL CENTER
CURRENTLY EJECTING ACROSS THE CHICAGO AREA...AND WILL PROVIDE THE
INITIAL WING OF FORCING AS IT TRANSLATES ACROSS MAINLY THE SOUTHERN
HALF OF THE FORECAST AREA EARLY IN THE DAY. THIS MAY PROVE
SUFFICIENT TOWARD SPARKING A FEW SHOWERS...LATEST HI RES GUIDANCE
AND RUC ANALYSIS IN SUPPORT OF A LOW POP MENTION EARLY ON. GREATEST
PROSPECTS FOR PRECIPITATION DEVELOPMENT WILL FOCUS INTO THE
AFTERNOON/EARLY EVENING AS LAPSE RATES STEEPEN CONSIDERABLY THROUGH
BOTH DAYTIME HEATING AND THE PASSAGE OF THE ATTENDANT COLD POOL
/-13C AT 500 MB/. A PERIOD OF GREATER CVA ACCOMPANYING THE MAIN
TROUGH PASSAGE WILL PROVIDE THE BACKGROUND FORCING TO SUPPORT A
SCATTERED COVERAGE OF SHOWERS AND THUNDERSTORMS GIVEN THE
THERMODYNAMIC PROFILE. THE OVERALL TEMPERATURE RECOVERY WILL BE
HINDERED BY LESS FAVORABLE INSOLATION POTENTIAL WITH CLOUD COVER
PROBLEMATIC. HIGHS IN THE LOW AND MIDDLE 70S.
LOW LEVEL COLD AIR ADVECTION TONIGHT AS DEEPER NORTHWEST FLOW
EMERGES ON THE BACKSIDE OF THE EXITING TROUGH. THE BETTER LOW LEVEL
DRYING WILL TAKE MORE TIME TO DEVELOP...NOTING THE SUBSTANTIAL LOW
CLOUD STILL EMANATING ACROSS THE MISSISSIPPI VALLEY THIS MORNING.
THIS POINTS TOWARD SOME LINGERING LOWER STRATUS FOR MUCH OF THE
OVERNIGHT PERIOD...A MORE GRADUALLY CLEARING TREND CLOSER TO
DAYBREAK. LOWS IN THE 50S.
LONG TERM...
TODAY`S SYSTEM WILL PHASE WITH ENERGY DIVING INTO ONTARIO THIS
MORNING TO PRODUCE A LARGE CLOSED LOW CENTERED OVER WESTERN QUEBEC
BY EARLY THURSDAY. AS A RESULT, DRY NORTHWEST FLOW IS FORECAST TO
DOMINATE OVER THE CENTRAL GREAT LAKES FOR THE REMAINDER OF THE WEEK.
WHILE EMBEDDED IMPULSES WITHIN PREVAILING CYCLONIC FLOW ALOFT WILL
PROPAGATE ACROSS THE AREA BOTH WED AND THURS, DEEP MOISTURE WILL
REMAIN WRAPPED AROUND THE OCCLUDING SURFACE LOW. THIS WILL ELIMINATE
CONCERNS FOR PRECIPITATION AND WILL SHIFT THE FOCUS TOWARD CLOUD
COVER EACH DAY. THE LARGEST CHANGE TO THE INHERITED FORECAST WAS TO
BUMP UP AFTN CLOUD COVER BOTH WED AND THURS GIVEN THE PROGGED
FAVORABLE TIMING OF UPPER WAVES WITH PEAK HEATING AND HIGHER
EXPECTATIONS FOR RESIDENT BOUNDARY LAYER MOISTURE GIVEN THE
COMBINATION OF YESTERDAY`S AND TODAY`S RAINFALL.
H85 TEMPS AROUND 10C COMBINED WITH CLOUDS WILL SUPPORT HIGHS IN MOST
PLACES NO BETTER THAN THE MID 70S ON WEDNESDAY. THE AFOREMENTIONED
PASSING UPPER WAVE WILL ORGANIZE A WEAK BAROCLINIC ZONE THAT WILL
PUSH SOUTH THROUGH THE CWA WEDNESDAY NIGHT. WITH H85 TEMPS TAKING
ANOTHER DIVE TO AROUND 6C THURSDAY, HIGHS WILL TOP OUT IN THE LOW
70S, PERHAPS ONLY REACHING THE UPPER 60S THE EASTERN THUMB AND ALONG
THE GLACIAL RIDGE.
EASTWARD PROGRESSION OF THE UPSTREAM UPPER RIDGE WILL FORCE SURFACE
HIGH PRESSURE TO TRANSLATE EASTWARD AND ULTIMATELY SETTLE JUST SOUTH
OF THE AREA ON THURSDAY NIGHT. EASING OF THE LOCAL PRESSURE GRADIENT
WILL RESULT MORE FAVORABLE RADIATING CONDITIONS. AS A RESULT,
DROPPED FORECAST HIGHS SEVERAL DEGREES INTO THE MID 40S OUTSIDE OF
THE METRO AREA. SUSPECT THAT THERE WILL STILL BE ENOUGH BOUNDARY
LAYER MOISTURE HANGING AROUND TO MAKE FOG A CONSIDERATION FOR
THURSDAY NIGHT, BUT WILL REFRAIN FROM INTRODUCING IT INTO THE
FORECAST AT SUCH AN EARLY STAGE. HIGHS WILL REBOUND INTO THE MID 70S
ON FRIDAY IN RESPONSE TO THE DEPARTURE OF THE THERMAL TROUGH.
MARINE...
A FRESH NORTHWEST BREEZE WILL GUST TO NEAR GALES ACROSS THE NORTHERN
HALF OF LAKE HURON LATE THIS AFTERNOON THROUGH THE FIRST HALF OF
TONIGHT AS COLDER AIR FILTERS INTO THE REGION. MARGINAL SMALL CRAFT
ADVISORY CONDITIONS WILL THEREFORE BE POSSIBLE LATE TONIGHT INTO
EARLY WEDNESDAY FOR THE EXPOSED NEARSHORE WATERS OF THE THUMB.
SURFACE HIGH PRESSURE WILL REMAIN UPSTREAM OF THE AREA WHICH WILL
PROMOTE A STEADY STATE MODERATE NORTHWEST FLOW THROUGH THURSDAY
NIGHT. GUSTS IN EXCESS OF 20 KNOTS WILL REMAIN COMMON OVER LAKE
HURON DURING THIS TIME. WINDS WILL EASE A BIT ON FRIDAY AS THE
CENTER OF HIGH PRESSURE SETTLES CLOSER TO THE REGION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....SF
UPDATE.......SF
SHORT TERM...MR
LONG TERM....JVC
MARINE.......JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS BUFFALO NY
206 PM EDT TUE AUG 12 2014
.SYNOPSIS...
A DEEPENING AREA OF LOW PRESSURE WILL MOVE FROM SOUTHERN LAKE HURON
NORTH ACROSS ONTARIO AND DRAG SEVERAL FRONTAL BOUNDARIES ACROSS
WESTERN AND CENTRAL NEW YORK WHICH WILL PRODUCE SEVERAL ROUNDS OF
SHOWERS AND SCATTERED THUNDERSTORMS. BEHIND THIS SYSTEM...EXPECT A
COUPLE OF DAYS OF UNSETTLED AND COOL WEATHER.
&&
.NEAR TERM /THROUGH TONIGHT/...
RADAR IMAGERY THIS AFTERNOON SHOWING OCCASIONAL SHOWERS CROSSING THE
EASTERN LAKE ONTARIO REGION. THIS IS NOT PARTICULARLY ORGANIZED...
BUT MOST LOCATIONS WILL STILL SEE SOME OCCASIONAL LIGHT RAIN.
FARTHER WEST JUST A FEW SCATTERED SHOWERS ARE LINGERING FROM THE
GENESEE VALLEY INTO THE WESTERN FINGER LAKES. THIS SHOULD REMAIN
LIGHT AND WIDELY SCATTERED. A BAND OF CONVECTION IS SLOWLY
INCREASING OVER CENTRAL LAKE ERIE AND EASTERN OHIO...WHICH WILL MOVE
EAST INTO WESTERN NY BY LATE AFTERNOON.
SATELLITE IMAGERY SHOWING A FEW BINOVC DEVELOPING OVER LAKE ERIE AND
THE NIAGARA FRONTIER. THESE BREAKS SHOULD ALLOW FOR JUST ENOUGH
SURFACE HEATING TO YIELD SBCAPE OF 1000-1500J/KG BY MID TO LATE
AFTERNOON WITH CONTRIBUTION TO DESTABILIZATION FROM MID LEVEL HEIGHT
FALLS AND COOLING WITH THE APPROACH OF A STRONG MID LEVEL TROUGH.
INCREASING ASCENT IN THE DPVA REGION AHEAD OF THIS TROUGH COMBINED
WITH LOW LEVEL CONVERGENCE ALONG A SURFACE COLD FRONT AND
DIFFERENTIAL HEATING BOUNDARIES SHOULD SUPPORT A BROKEN BAND OF
CONVECTION BY LATE AFTERNOON ACROSS FAR WESTERN NY...WITH SUPPORT OF
THIS FROM MESOSCALE MODEL GUIDANCE SUCH AS THE HRRR AND THE SSEO.
DEEP LAYER 0-6KM SHEAR OF AROUND 40 KNOTS COMBINED WITH MODEST BUT
SUFFICIENT INSTABILITY AND GOOD SYNOPTIC SUPPORT MAY ALLOW
CONVECTION TO GROW UPSCALE INTO ORGANIZED CLUSTERS AND BOWING
SEGMENTS...WITH SOME RISK OF ISOLATED DAMAGING WINDS. SOME OF THE
STRONGER CORES MAY ALSO PRODUCE MARGINAL SEVERE HAIL AND LOCALLY
HEAVY RAINFALL. GREATEST RISK OF SEVERE WILL BE FROM MID AFTERNOON
THROUGH MID EVENING FROM THE GENESEE VALLEY WESTWARD.
THE COLD FRONT CROSSES THE REGION OVERNIGHT JUST REACHING THE
EASTERN BORDER OF THE CWA TOWARD MORNING. THIS COMBINED WITH THE
APPROACH OF THE MID LEVEL TROUGH AXIS AND ASSOCIATED LARGE SCALE
ASCENT WILL KEEP SHOWERS AND A FEW THUNDERSTORMS GOING OVERNIGHT
WITH THE FOCUS FOR MORE ORGANIZED RAIN SHIFTING TO CENTRAL NY.
RAINFALL WISE...MOST AREAS CAN EXPECT TO SEE TOTALS OF ONE TO ONE
AND A HALF INCHES WITH THE GREATEST BASIN AVERAGE AMOUNTS EXPECTED
EAST OF LAKE ONTARIO. GIVEN THE RECENT DRY SPELL THESE AMOUNTS
SHOULD NOT POSE ANY BIG HYDRO CONCERNS. LOCALIZED HEAVIER
THUNDERSTORM RAINS COULD HOWEVER PRODUCE SOME LOCALIZED POOR
DRAINAGE ISSUES.
WINDS WILL INCREASE ACROSS THE EASTERN SECTIONS OF THE CWA LATER
TODAY/TONIGHT. BLACK RIVER VALLEY MAY SEE GUSTS APPROACHING 40 MPH.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
A DEEPENING UPPER LOW WILL MOVE FROM ITS CURRENT POSITION OVER THE
CENTRAL GREAT LAKES TO QUEBEC BY THURSDAY. THE ASSOCIATED SURFACE
COLD FRONT WILL LIKELY BE JUST EAST OF THE FORECAST AREA AS WE OPEN
THE DAY WEDNESDAY...NONETHELESS WITH SUCH STRONG UPPER LEVEL
TROUGHING MOVING OVERHEAD THE REGION...EXPECT SCATTERED SHOWERS TO
LINGER ACROSS THE AREA...PARTICULARLY ACROSS THE NORTH COUTNRY WHERE
A PRONOUNCED UPSLOPE WESTERLY FLOW WILL AID IN ENHANCING SHOWER
CHANCES. THE COMBINATION OF INCREASINGLY COOL AIR ARRIVING ACROSS
THE REGION AND CLOUDINESS ASSOCIATED WITH THE UPPER LEVEL TROUGH
WILL KEEP TEMPERATURES WELL BELOW NORMAL WEDNESDAY WITH HIGHS
RANGING FROM THE MID-60S TO THE LOWER 70S.
SHOWER CHANCES WILL DIMINISH WEDNESDAY NIGHT BETWEEN THE LOSS OF
DIURNAL HEATING AND THE ADVECTION OF DRIER AIR OUT OF THE CANADIAN
ARCTIC ACROSS THE REGION. THAT SAID...WITH SUCH A STRONG TROUGH
HANGING AROUND...CANNOT RULE OUT A STRAY SHOWER OR
TWO...PARTICULARLY ACROSS THE NORTH COUTNRY WHERE WESTERLY UPSLOPE
FLOW. LOOK FOR LOWS IN THE 50S WEDNESDAY NIGHT.
THURSDAY AND THURSDAY NIGHT WILL BE THE COOLEST PARTS OF THE WEEK AS
THE AFOREMENTIONED COLD ADVECTION REACHES ITS PEAK WITH 850MB TEMPS
DROPPING AS LOW AS +5 TO +7C. THIS WILL ONLY SUPPORT HIGHS IN THE
60S ACROSS THE FORECAST AREA WITH LOW TO MID 50S THURSDAY
NIGHT...WHILE PORTIONS OF THE SOUTHERN TIER WILL LIKELY FALL INTO
THE UPPER 40S. THE MITIGATING FACTOR IN KEEPING TEMPERATURES FROM
PLUNGING LOWER THURSDAY NIGHT WILL BE THE PERSISTENT WESTERLY FLOW
AND RESULTING LAKE EFFECT CLOUD COVER. SPEAKING OF LAKE
EFFECT...WITH TEMPERATURES ALOFT COOLING TO +5C...WE MAY SEE MORE
LAKE ENHANCED/UPSLOPE SHOWER ACTIVITY EAST OF LAKE ONTARIO THURSDAY
AND THURSDAY NIGHT WHILE PERSISTENT DRY AIR ALOFT WILL KEEP SHOWERS
LIMITED TO JUST A SLIGHT CHANCE ELSEWHERE.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE UPPER LEVEL LOW WILL DRIFT ACROSS QUEBEC FRIDAY BEFORE
EVENTUALLY LIFTING NORTHEAST INTO LABRADOR THIS WEEKEND. WITHT HE
DEPARTURE OF THE LOW AND ASSOCIATED TROUGHING...TEMPERATURES WILL
RECOVER NICELY BACK INTO THE 70S BY THE WEEKEND AS HIGH PRESSURE
SLIDES BY TO OUR SOUTH.
WHILE FRIDAY NIGHT AND SATURDAY LOOK TO BE DRY FOR MUCH OF THE
FORECAST AREA...CONDITIONS MAY BECOME MORE UNSETTLED FOR THE SECOND
HALF OF THE WEEKEND AND POSSIBLY INTO MONDAY AS ANOTHER SHORTWAVE IS
PROGGED TO DROP ACROSS THE GREAT LAKES. MODEL AGREEMENT ON THE
POSITION/TIMING OF THIS FEATURE IS SHAKY AT BEST AT THIS TIME
HOWEVER...PARTICULARLY AS SOME SOLUTIONS HAVE THIS FEATURE
INTERACTING WITH A CUTOFF LOW DRIFTING OUT OF THE CENTRAL PLAINS
STATES. GIVEN ALL OF THIS UNCERTAINTY...AM KEEPING POPS IN THE
SLIGHT CHANCE RANGE FOR NOW WITH TEMPERATURES TRENDING TOWARDS
CLIMATOLOGY WITH HIGHS IN THE UPPER 70S AND LOWS IN THE UPPER
50S/LOWER 60S.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
THE LOWER ELEVATIONS HAVE IMPROVED MAINLY TO VFR THIS AFTERNOON WITH
SOME MVFR/IFR CIGS LINGERING ACROSS HIGHER TERRAIN. THIS WILL
CONTINUE FOR SEVERAL MORE HOURS. OCCASIONAL RAIN SHOWERS WILL
CONTINUE THROUGH MID TO LATE AFTERNOON ACROSS THE EASTERN LAKE
ONTARIO REGION...BUT CIGS/VSBY WILL BE VFR MUCH OF THE TIME IN THIS
ACTIVITY. FARTHER WEST...A BAND OF CONVECTION IS EXPECTED TO MOVE
INTO WESTERN NY BY 20-21Z WITH A 1-3 HOUR PERIOD OF TSRA AND BRIEF
REDUCTIONS TO MVFR/IFR CONDITIONS INCLUDING KBUF-KIAG-KJHW. THIS
WILL MOVE EAST AND CROSS THE GENESEE VALLEY INCLUDING KROC DURING
THE 22Z-01Z TIME FRAME...THEN SLOWLY WEAKEN AND BROADEN INTO A
LARGER AREA OF RAIN WITH A FEW EMBEDDED THUNDERSTORMS OVERNIGHT EAST
OF LAKE ONTARIO. THIS WILL CONTINUE TO PRODUCE AREAS OF MVFR/IFR IN
THAT AREA INCLUDING KART.
BEHIND THE AREA OF CONVECTION...A PERIOD OF IFR CIGS APPEARS LIKELY
AGAIN OVERNIGHT ACROSS THE HIGHER TERRAIN OF THE SOUTHERN TIER AND
FINGER LAKES WITH MOIST LOW LEVEL UPSLOPE FLOW. BOUNDARY LAYER
MIXING AND CLOUD COVER SHOULD PREVENT MUCH IN THE WAY OF
FOG...ALTHOUGH A FEW HILLTOPS MAY GET INTO LOCAL FOG IF THE STRATUS
LAYER INTERSECTS THE TERRAIN.
ON WEDNESDAY THE LOW CIGS ACROSS THE HIGHER TERRAIN WILL IMPROVE TO
MVFR BY LATE MORNING WITH FURTHER IMPROVEMENT TO VFR BY AFTERNOON.
STEADIER RAIN EAST OF LAKE ONTARIO EARLY WITH LOCAL MVFR/IFR WILL
TAPER OFF. ANOTHER BROKEN BAND OF SHOWERS WILL MOVE INTO WESTERN NY
VERY EARLY WEDNESDAY MORNING THEN PROGRESS EAST ACROSS THE AREA
DURING THE DAY WITH A BRIEF PERIOD OF MVFR. SCATTERED SHOWERS AND
ISOLATED THUNDER WILL DEVELOP DURING THE AFTERNOON INLAND FROM THE
LAKES BUT COVERAGE SHOULD REMAIN RATHER SPARSE WITH VFR PREVAILING
IN MOST PLACES DURING THE AFTERNOON.
OUTLOOK...
THURSDAY AND FRIDAY...VFR WITH A CHANCE OF MVFR IN SHOWERS
ESPECIALLY EAST OF THE LAKES.
SATURDAY...VFR.
SATURDAY NIGHT AND SUNDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.
&&
.MARINE...
UNSETTLED WEATHER WILL MOVE INTO THE LOWER GREAT LAKES REGION AS A
DEEPENING LOW MOVES FROM SOUTHERN LAKE HURON ACROSS ONTARIO AND ONTO
QUEBEC. S WINDS WILL CONTINUE TO PRODUCE SMALL CRAFT ADVISORY
CONDITIONS AT THE EAST END OF LAKE ONTARIO THIS AFTERNOON.
ADDITIONAL SCA MAY BE NEEDED POST COLD-FRONTAL LATER
TONIGHT/WEDNESDAY. COOLER TEMPERATURES ALOFT WILL BE MARGINALLY
FAVORABLE FOR FOR WATERSPOUT FORMATION WEDNESDAY THROUGH THE END
OF THE WEEK.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR LOZ044-
045.
&&
$$
SYNOPSIS...HITCHCOCK/LEVAN
NEAR TERM...HITCHCOCK/LEVAN
SHORT TERM...WOOD
LONG TERM...WOOD
AVIATION...HITCHCOCK
MARINE...HITCHCOCK/LEVAN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
330 PM EDT TUE AUG 12 2014
.SYNOPSIS...
LINGERING TROPICAL MOISTURE ACROSS THE CAROLINAS WILL TRIGGER
SCATTERED SHOWERS AND THUNDERSTORMS THROUGH EARLY WEDNESDAY. A
COLD FRONT WILL CROSS THE COAST OVERNIGHT WEDNESDAY...BRINGING A
DRYING TREND ALONG WITH COOLER OVERNIGHT TEMPERATURES. SEASONABLE
WEATHER FOR MID-AUGUST IS EXPECTED EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 330 PM TUESDAY...VISIBLE SATELLITE IMAGERY SHOWS A WELL-
DEFINED COLD FRONT FROM THE GREAT LAKES EXTENDING SOUTH INTO
TENNESSEE AND NORTHERN ALABAMA. AHEAD OF THIS FRONT A MARITIME
TROPICAL AIRMASS WITH PRECIPITABLE WATER VALUES OF AS HIGH AS 2.2
INCHES IS YIELDING SCATTERED SHOWERS & T-STORMS...MAINLY ACROSS
SOUTH CAROLINA BUT ALSO EXPANDING IN COVERAGE ACROSS WESTERN AND
CENTRAL NC. SURFACE-BASED CAPE IS AS HIGH AS 2500 J/KG AND SHOULD
PROVIDE PLENTY OF FUEL FOR THESE STORMS THROUGH THE LATE AFTERNOON
AND EVENING HOURS.
A RELATIVELY DEEP UPPER TROUGH FROM THE WESTERN GREAT LAKES EXTENDS
DOWN THROUGH THE MISSISSIPPI RIVER VALLEY. ACCELERATING MID-LEVEL
FLOW AHEAD OF THIS TROUGH WILL LEAD TO FASTER STORM MOTION THAN WE
HAVE SEEN OVER THE PAST SEVERAL DAYS...15-20 MPH AND POTENTIALLY
INCREASING FURTHER IF A WELL-DEFINED COLD POOL CAN DEVELOP AND PUSH
STORMS OUTWARD DUE TO THERMAL/DENSITY-DRIVEN EFFECTS.
I HAVE HELD FORECAST POPS TONIGHT IN THE 40-50 PERCENT RANGE WITH
THE EXCEPTION OF THE 60-70 POPS OVER THE NEXT FEW HOURS ACROSS
WILLIAMSBURG AND SOUTHERN FLORENCE COUNTIES. THE REASON I DON`T FEEL
COMFORTABLE GOING HIGHER IS THE LACK OF UPPER LEVEL SUPPORT FOR
STORMS. A 250 MB JET STREAK IS FAVORABLY VENTILATING THE STORMS
ACROSS THE NC/VA FOOTHILLS BUT IS SHOWN ON 12Z MODELS TO REMAIN TOO
FAR WEST TO DIRECTLY IMPACT OUR STORMS ACROSS THE EASTERN CAROLINAS.
AT 500 MB A STRUNG-OUT VORT MAX AHEAD OF THE UPPER TROUGH IS
BECOMING CHANNELED ALONG WITH THE GEOSTROPHIC FLOW AND MAY NOT BE
ABLE TO ENHANCE UPWARD MOTION AS IT APPROACHES THE AREA OVERNIGHT.
UTILIZING MOS BIASES OBSERVED OVER THE PAST FEW DAYS MY FORECAST
LOWS ARE A BIT ABOVE GUIDANCE TONIGHT...74-77 AT THE COAST AND 71-74
INLAND.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 330 PM TUESDAY...A COLD FRONT WILL BE DRAPED ACROSS OUR CWA
WED MORNING...LIKELY BISECTING OUR INLAND AND COASTAL ZONES AT THE
START OF THE PERIOD. AHEAD OF THE FRONT...FORECAST SOUNDINGS
DEPICT ENOUGH MOISTURE TO WARRANT MAINTAINING SLIGHT CHC POPS
MAINLY ALONG THE COAST BEFORE 18Z WED. AS THE UPPER TROUGH AXIS
MOVES OFFSHORE WED AFTN...DRIER AIR WILL QUICKLY FILTER INTO THE
AREA WITH SUBSIDENCE ALOFT EFFECTIVELY BRINGING AN END TO OUR RAIN
CHANCES. THE COLD FRONT WILL FINALLY PUSH THROUGH LATE WED/EARLY
THU...AS PWATS CONTINUE TO FALL TO BELOW 1.0 INCH BY 12Z THU.
AFTER NEARLY A WEEK OF CLOUDY AND RAINY WEATHER...THU WILL BE A
WELCOMED RELIEF AS MOSTLY SUNNY AND DRY CONDITIONS PREVAIL ACROSS
THE EASTERN CAROLINAS.
EXPECT NEAR SEASONABLE HIGHS ON WED WITH SLIGHT COOLER DAYTIME TEMPS
ON THU...MID TO UPPER 80S...IN THE WAKE OF THE COLD FRONT. OVERNIGHT
LOWS WILL RUN SEVERAL DEGREES BELOW NORMAL BOTH NIGHTS...GENERALLY
MID TO UPPER 60S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 330 PM TUESDAY...A RETURN TO SUMMER-LIKE WEATHER WILL
FINALLY OCCUR AS FLOW FLATTENS ALOFT AND OFFSHORE HIGH PRESSURE
BECOMES THE DOMINANT SYNOPTIC FEATURE.
LARGE UPPER TROUGH WILL PERSIST ACROSS THE EASTERN CONUS INTO
SATURDAY...BUT FORTUNATELY IN A WEAKENING STATE. TROUGH AXIS
OVERHEAD FRIDAY KEEPS DRY WESTERLY FLOW ALOFT...AND THUS PWATS
REMAIN LESS THAN 1.5 INCHES WHICH COMBINED WITH BELOW NORMAL TEMPS
SUGGESTS LIMITED TO NO CONVECTIVE POTENTIAL FRIDAY. CANNOT RULE OUT
AN ISOLATED SHOWER OR STORM ALONG THE SEA BREEZE FRIDAY...BUT WILL
KEEP ONLY LESS THAN 20 POP ALONG THE COAST. UPPER TROUGH REMAINS IN
PLACE ON SATURDAY...WHICH WHEN COMBINED WITH SLOWLY INCREASING TEMPS
AND ENHANCED MOIST RETURN FLOW...WILL SUPPORT SLIGHTLY GREATER
CHANCES FOR AFTN CONVECTION ON SATURDAY.
MORE TYPICAL AUGUST WEATHER DEVELOPS SUNDAY AND PERSISTS INTO NEXT
WEEK AS HIGH PRESSURE OFFSHORE BECOMES THE PRIMARY SENSIBLE-WEATHER
MAKER...AND THE UPPER TROUGH FLATTENS ALLOWING FOR BROAD RIDGING TO
DEVELOP ACROSS THE SOUTHERN TIER. WHILE THIS WILL CREATE A SLOW
WARMING TREND...WITH TEMPS RISING TO SLIGHTLY ABOVE CLIMO NEXT
WEEK...IT WILL ALSO SUPPORT INCREASING CONVECTIVE CHANCES AS PWATS
RISE BACK TOWARDS 2 INCHES AND THE PIEDMONT TROUGH BECOMES ACTIVE.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...THE HRRR MODEL CONTINUES TO TREND THE CONVECTION LATER
IN THE AFTERNOON AND INTO EVENING HOURS. THERE SHOULD ALSO BE SOME
CONVECTION ALONG THE RESULTANT BOUNDARY A BIT EARLIER...HOWEVER MOST
OF THE ACTIVITY WILL BE INLAND FROM THE COASTAL TERMINALS. BRIEF
HEAVY RAIN IS EXPECTED WITH PWATS OVER TWO INCHES NEAR THE COAST.
TONIGHT...CONVECTION WILL FINALLY WIND DOWN AROUND 02-03Z...WITH
PATCHY FOG EXPECTED...MAINLY IN THE AREAS WHERE IT RAINED. WINDS
WILL SHIFT TO THE WEST WEDNESDAY AS A FRONT PUSHES THROUGH THE
REGION. THERE IS A SLIGHT CHANCE FOR SHOWERS IMMEDIATELY ALONG THE
FRONT TOMORROW...CONFIDENCE LOW.
EXTENDED OUTLOOK...VFR THURS THROUGH SAT. CHANCE FOR SHOWERS SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 PM TUESDAY...ALL EYES ARE FOCUSED ON A COLD FRONT
EXTENDING SOUTH FROM THE GREAT LAKES INTO EASTERN TENNESSEE AND
NORTHERN ALABAMA. THIS FRONT WILL MOVE INTO THE COASTAL PLAIN LATE
TONIGHT. AHEAD OF THE FRONT SOUTHWEST WINDS WILL INCREASE TO 10-15
KNOTS WITH SEAS BUILDING FROM THE CURRENT 2 FT TO AS HIGH AS 3-4
FT AWAY FROM SHORE OVERNIGHT. SCATTERED SHOWERS AND T-STORMS HAVE
DEVELOPED INLAND WITH SOME ISOLATED CELLS FIRING UP ALONG THE
SEABREEZE BOUNDARY VERY CLOSE TO THE BEACHES. ISOLATED CONVECTION
THIS AFTERNOON WILL TEND TO BECOME A LITTLE MORE WIDESPREAD THIS
EVENING...PERHAPS CONTINUING OVERNIGHT AS WARM AND HUMID SOUTHWEST
WINDS CONTINUE. BESIDES LIGHTNING...THE BIGGEST RISK WITH THESE
STORMS MAY BE SUDDEN VISIBILITY RESTRICTIONS IN HEAVY RAINFALL.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 330 PM TUESDAY...SOUTHWEST FLOW 10-15 KT AHEAD OF AN
APPROACHING COLD FRONT WILL PRODUCE 3-4 FT SEAS DURING THE DAY
WED. THIS FRONT WILL FINALLY PUSH OFFSHORE OVERNIGHT WED...WITH
WINDS BECOMING NORTHWEST AOB 10 KTS EARLY THU MORNING. WEAK
PRESSURE GRADIENT DURING THE DAY THU WILL RESULT IN LIGHT
NORTHEAST WINDS... BECOMING VRBL INTO THU NIGHT. SEAS ON THU WILL
GRADUALLY SUBSIDE TO 2-3 FT DURING THE DAY AND EVENTUALLY 2 FT BY
THE END OF THE PERIOD.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 330 PM TUESDAY...AFTER A BRIEF PERIOD OF VARIABLE WINDS
EARLY FRIDAY...HIGH PRESSURE OFFSHORE WILL BECOME THE CONTROLLING
SYNOPTIC FEATURE...AND WINDS WILL BE PRIMARILY S/SW THROUGH THE
PERIOD. ALTHOUGH THE PRESSURE GRADIENT WILL REMAIN RELAXED FRI AND
SAT...BY SUNDAY IT WILL BEGIN TO TIGHTEN...AND THUS WINDS WILL
RISE FROM 5-10 KTS FRI/SAT...TO 10-15 KTS SUNDAY...WITH A MORE
VEERED DIRECTION TO SW. SEAS OF AROUND 2 FT WILL BE COMMON
FRI/SAT...RISING TO 2-4 FT ON SUNDAY THANKS TO THE STRONGER WINDS
AND A SLOWLY AMPLIFYING SE SWELL.
&&
.TIDES/COASTAL FLOODING...
AS OF 330 PM TUESDAY...STRONG ASTRONOMICAL TIDES WITH THIS WANING
FULL MOON CYCLE WILL REQUIRE ANOTHER COASTAL FLOOD ADVISORY WITH
TONIGHTS HIGH TIDE FOR THE LOWER CAPE FEAR RIVER SIMILAR TO THE
LAST 3 EVENINGS...BUT LIKELY A FEW INCHES LOWER ON THE PEAK WATER
LEVELS. ELEVATED LEVELS WILL BE OBSERVED ALONG THE BANKS OF THE
ICW AS WELL DURING HIGH TIDE LATE TONIGHT. THE LOWER CAPE FEAR
RIVER WILL EXPERIENCE MINOR COASTAL FLOODING INCLUDING LOCALIZED
AREAS OF DOWNTOWN WILMINGTON. NO COASTAL FLOOD ADVISORIES FOR THE
BEACHES EXPECTED AS ASTRONOMICAL PULLS HAVE ABATED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY FROM 11 PM THIS EVENING TO 2 AM EDT
WEDNESDAY FOR NCZ107.
MARINE...NONE.
&&
$$
SYNOPSIS...BJR
NEAR TERM...TRA
SHORT TERM...BJR
LONG TERM...JDW
AVIATION...DL
MARINE...TRA/JDW/BJR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1246 PM EDT TUE AUG 12 2014
.SYNOPSIS...
LINGERING TROPICAL MOISTURE ACROSS THE CAROLINAS WILL TRIGGER
SCATTERED TORRENTIAL SHOWERS AND THUNDERSTORMS THROUGH EARLY
WEDNESDAY. A COLD FRONT WILL CROSS THE COAST EARLY ON THURSDAY...
BRINGING A DRYING TREND ALONG WITH COOLER OVERNIGHT TEMPERATURES.
SEASONABLE WEATHER FOR MIDDLE AUGUST IS EXPECTED EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM TUESDAY...RADAR SHOWS THE FIRST SHOWERS OF THE DAY HAVE
DEVELOPED ACROSS WILLIAMSBURG COUNTY SC. SATELLITE SHOWS THE CUMULUS
FIELD IS MOST "AGITATED" FROM THERE EASTWARD TO GEORGETOWN. A PEEK
OUTSIDE THE WEATHER OFFICE SHOWS THE CUMULUS OVER WILMINGTON HAVE
ONLY MINOR VERTICAL GROWTH SO FAR. NO SIGNIFICANT CHANGES ARE BEING
MADE TO THE FORECAST AT THIS TIME. PREVIOUS DISCUSSION FROM 1030 AM
FOLLOWS...
THIS MORNING`S FORECAST UPDATE FEATURES NO SIGNIFICANT CHANGES FROM
THE PREVIOUS FORECAST. THE STATIONARY FRONT THAT HAD BEEN STALLED
ACROSS SOUTH CAROLINA FOR THE PAST COUPLE OF DAYS HAS LIFTED
NORTHWARD INTO NORTHERN NORTH CAROLINA...ACCOMPANIED BY A WEAK AREA
OF LOW PRESSURE. THIS WILL REMOVE SOME OF THE LOW-LEVEL FORCING THAT
FAVORED WIDESPREAD THUNDERSTORM ACTIVITY OVER THE PAST FEW DAYS.
MORNING LOW STRATUS AND FOG IS BURNING OFF AND SHOULD HAVE ITS
MOISTURE INCORPORATED INTO AN ACTIVE CUMULUS FIELD THIS AFTERNOON.
THE ATMOSPHERE IS VERY MOIST AND CONDITIONALLY UNSTABLE.
PRECIPITABLE WATER VALUES WERE 2.1 TO 2.2 INCHES ON THE 12Z MHX AND
CHS SOUNDINGS. ASSUMING HIGH TEMPERATURES REACH THE UPPER 80S TO
AROUND 90 LOOK FOR SURFACE-BASED CAPE TO RISE TO NEAR 2000 J/KG WITH
NO CAPPING AND LIFTED INDICES AROUND -5. STEERING FLOW AND SURFACE
WINDS ARE CURRENTLY VERY LIGHT...BUT AS THE DAY PROGRESSES AN
APPROACHING UPPER LEVEL TROUGH AND SURFACE COLD FRONT (NOW ACROSS
THE OHIO VALLEY INTO TENNESSEE) WILL CAUSE AN ACCELERATION OF WINDS
THROUGHOUT THE TROPOSPHERE. THIS WILL NOT APPRECIABLY AFFECT STORM
ORGANIZATION BUT WILL INCREASE STORM MOTION TO 15-20 MPH BY LATE IN
THE DAY. HIGH PRECIPITABLE WATER VALUES PLUS A VERY DEEP WARM CLOUD
LAYER FOR EFFICIENT COALESCENCE-DOMINATED PRECIPITATION PROCESSES TO
OCCUR BOTH ARGUE FOR INCLUSION OF HEAVY RAIN MENTION IN THE FORECAST
AGAIN THIS AFTERNOON INTO EARLY THIS EVENING. THE FREEZING LEVEL IS
FORECAST TO REACH 16KFT THIS AFTERNOON.
RECENT HRRR MODEL RUNS ARE FOCUSED ON TWO AREAS FOR CONVECTIVE
INITIATION LATER TODAY: THE SEABREEZE BOUNDARY ALONG THE COAST...AND
THE SC MIDLANDS/PEE DEE REGION. I HAVE INCREASED POPS TO NEAR 60
PERCENT FOR THE FLORENCE AREA LATE THIS AFTERNOON INTO EARLY THIS
EVENING AS THE BULK OF RECENT MODEL DATA PAINTS THE BEST POTENTIAL
FOR THUNDERSTORMS HERE. FEWER CHANGES WERE NEEDED ELSEWHERE.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 330 AM TUESDAY...THE UPPER LONGWAVE PATTERN THRU THIS PERIOD
WILL EXHIBIT A WELL AMPLIFIED TROF AFFECTING THE UNITED STATES
EAST OF THE MISSISSIPPI RIVER. THIS HAS BEEN PLAYED OUT FOR MUCH
OF THIS SUMMER SEASON. AT THE SFC...THE FA WILL HAVE TO DEAL WITH
A COLD FRONTAL PASSAGE DURING WEDNESDAY...ALTHOUGH MODELS HAVE
BEEN TRENDING WITH SLOWER CFP DURING THE PAST FEW RUNS. AS A
RESULT...HAVE INCLUDED CHANCE POPS UP THRU SUNSET WEDNESDAY. THE
DAYS INSOLATION WILL ADD INSTABILITY TO THE LOCAL ATM. A MID-LEVEL
VORT MAX IS PROGGED TO ROUND THE BASE OF THE UPPER LONGWAVE TROF
DURING WED AFTN AND ACROSS THE FA...FURTHER ADDING DYNAMICS AND
UVVS TO THE MIX. SOME OF THESE STORMS COULD END UP BEING STRONG TO
POSSIBLY SEVERE AS DRIER AIR ALOFT AND INCREASING WIND SPEED SHEAR
THRU THE ATM PROFILE. AGAIN NOT LOOKING AT WIDESPREAD
PCPN...SHOULD BE SCATTERED AT BEST. VARIOUS MODEL MOS GUIDANCE
SIMILAR WITH MAX TEMPS WED...RUNNING ATLEAST A CAT ABOVE CLIMO
NORMS.
FOR WED NIGHT THRU THU NIGHT...THE MEAN UPPER LONGWAVE N-S TROF AXIS
TO RESIDE OVERHEAD OR JUST WEST OF THE ILM CWA. THIS POSITIONING
WILL BE IMPORTANT WITH REGARD TO HOW FAR SOUTH AND EAST THE COLD
FRONT PROGRESSES BEFORE STALLING AS IT BECOMES ORIENTED PARALLEL TO
THE UPPER FLOW. FOR NOW...WILL MAINTAIN ITS FINAL POSITIONING WELL
SOUTH AND EAST OF THE ILM CWA DURING THIS PERIOD. AS A
RESULT...DRIER AIR WILL INFILTRATE THE FA. NOT NECESSARILY
COOLER...DUE TO THE ATM HAVING BEEN UNDER OVERCAST SKIES AND OFF AND
ON PCPN FOR THE PAST 3-4 DAYS. WILL ILLUSTRATE NO POPS FOR WED NITE
THRU THU NITE GIVEN THE SUBSIDENCE PREVAILING ACROSS THE FA. STILL
ENOUGH MOISTURE IN THE LOW LEVELS FOR DIURNALLY DRIVEN CU FOR
DAYLIGHT THU. MAX/MIN TEMPS TO RUN ONE TO 2 CAT BELOW NORMAL.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 330 AM TUESDAY...THE START OF THIS PERIOD...MODELS CONTINUE
WITH A WELL AMPLIFIED LONGWAVE UPPER TROF AFFECTING THE EASTERN
1/3RD OF THE U.S...WHICH INCLUDES THE ILM CWA. THE MEAN N-S UPPER
TROF AXIS TO LIE NEARLY OVERHEAD. THIS IS IMPORTANT BECAUSE THE
STALLED/STATIONARY SFC FRONT WILL REMAIN JUST FAR ENOUGH EAST AND
SOUTH OF THE FA...AND SO DOES THE PCPN ASSOCIATED WITH IT. FOR
FRI...JUST ENOUGH INSTABILITY AND LOW LEVEL MOISTURE AVBL FOR A
LOW CHANCE POP ALONG THE COASTAL COUNTIES FOR ANY SEA BREEZE
INDUCED SHOWERS OR THUNDERSTORMS.
DURING THE UPCOMING WEEKEND...MODEL CONSENSUS IS FOR THIS LONGWAVE
UPPER TROF TO DE-AMPLIFY AND FLATTEN-SOME. LOOK FOR A BETTER CHANCE
FOR DIURNALLY DRIVEN CONVECTION BY SUNDAY AND ESPECIALLY INTO NEXT
WEEK AS THE MOISTURE AND INSTABILITY RETURN. THE SFC PIEDMONT TROF
TO RETURN AND THE DAILY SEA BREEZE WILL PROVIDE THE FORCING TO AID
THE DIURNALLY DRIVEN CONVECTION. HAVE LEANED TOWARD THE GFS SOLUTION
WITH BERMUDA RIDGING TO POSSIBLY AFFECT THE FA AT THE END OF THE
LONG TERM PERIOD.
MAX/MIN TEMPS TO START OUT SLIGHTLY BELOW CLIMO NORMS FRI...THEN
MODERATE TO NEAR OR SLIGHTLY ABOVE NORMAL DURING THE REMAINDER OF
THE LONG TERM PERIOD.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...THE HRRR MODEL CONTINUES TO TREND THE CONVECTION LATER
IN THE AFTERNOON AND INTO EVENING HOURS. THERE SHOULD ALSO BE SOME
CONVECTION ALONG THE RESULTANT BOUNDARY A BIT EARLIER...HOWEVER MOST
OF THE ACTIVITY WILL BE INLAND FROM THE COASTAL TERMINALS. BRIEF
HEAVY RAIN IS EXPECTED WITH PWATS OVER TWO INCHES NEAR THE COAST.
TONIGHT...CONVECTION WILL FINALLY WIND DOWN AROUND 02-03Z...WITH
PATCHY FOG EXPECTED...MAINLY IN THE AREAS WHERE IT RAINED. WINDS
WILL SHIFT TO THE WEST WEDNESDAY AS A FRONT PUSHES THROUGH THE
REGION. THERE IS A SLIGHT CHANCE FOR SHOWERS IMMEDIATELY ALONG THE
FRONT TOMORROW...CONFIDENCE LOW.
EXTENDED OUTLOOK...VFR THURS THROUGH SAT. CHANCE FOR SHOWERS SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM TUESDAY...THE SEABREEZE HAS FORMED AT THE BEACHES WHERE
VIRTUALLY ALL OBSERVATIONS NOW SHOW A SOUTH WIND. SHOWERS ARE
BEGINNING TO DEVELOP ACROSS SOUTH CAROLINA 10-50 MILES INLAND FROM
THE COAST. UNLESS ONE OR TWO SNEAK ACROSS THE SEABREEZE BOUNDARY IT
APPEARS DRY WEATHER SHOULD PERSIST UNTIL LATE AFTERNOON. PREVIOUS
DISCUSSION FROM 1030 AM FOLLOWS...
WEAK LOW PRESSURE ALONG A FRONT THAT HAD BEEN STALLED ACROSS SOUTH
CAROLINA FOR THE PAST COUPLE OF DAYS IS ON THE MOVE. ACCORDING TO
LATEST WIND DATA THE FRONT ALREADY HAS PUSHED AS FAR NORTH AS
HATTERAS ISLAND. THIS LEAVES A LIGHT SOUTHWESTERLY WIND ACROSS OUR
PORTION OF THE CAROLINAS. INCREASING WIND SPEEDS ARE EXPECTED THIS
AFTERNOON NEARSHORE AS A WEAK TO MODERATE SEABREEZE CIRCULATION
DEVELOPS. WINDS AT THE BEACHES SHOULD INCREASE TO NEAR 12 KNOTS.
A COLD FRONT WILL APPROACH FROM THE WEST LATE TONIGHT. ACCELERATING
WINDS AHEAD OF THIS FEATURE SHOULD PUSH WIND SPEEDS CLOSER TO 15
KNOTS OVERNIGHT...ESPECIALLY AWAY FROM SHORE. SEAS CURRENTLY 2-3
FEET WILL BUILD TO 3-4 FT OVERNIGHT...ESPECIALLY AWAY FROM SHORE.
RADAR AND SATELLITE SHOW CLEAR CONDITIONS ACROSS THE WATERS
CURRENTLY. SCATTERED THUNDERSTORMS SHOULD DEVELOP THIS AFTERNOON
ALONG THE SEABREEZE BOUNDARY JUST INLAND FROM THE COAST. ATMOSPHERIC
STEERING FLOW IS FROM THE WEST WHICH WILL TRY TO PUSH THESE STORMS
ACROSS THE SEABREEZE FRONT INTO THE OCEAN. BETTER CHANCES MAY
DEVELOP THIS EVENING AS A LARGE CLUSTER OF STORMS EXPECTED TO
DEVELOP ACROSS SOUTH CAROLINA THIS AFTERNOON RUNS EAST TOWARD THE
COAST.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM TUESDAY...AHEAD OF THE COLD FRONT DURING
WEDNESDAY...LOOK FOR A TIGHTENED SFC PG AND A PATTERN THAT YIELDS
SW TO WSW WINDS AROUND 15 KT...OCCASIONALLY UP TO 20 KT. THE CFP
IS SLATED FOR WED AFTN AND EVENING. WILL BE LOOKING AT WINDS
VEERING TO THE NW-NE WED NITE THRU THU WITH SPEEDS AROUND 15 KT
THEN DIMINISHING THU AFTN AND NIGHT AS THE COLD FRONT STALLS TO
THE SOUTH AND THE SFC PG RELAXES. MODELS INDICATE RATHER BROAD
HIGH PRESSURE TO RIDGE IN FROM THE NW WITH WIND DIRECTIONS
BECOMING SOMEWHAT VARIABLE IN DIRECTION BY THU NIGHT. SIGNIFICANT
SEAS WILL PEAK IN THE 3 TO POSSIBLY 5 FOOT RANGE DURING WEDNESDAY
INTO WED EVENING AND MAINLY BE A FUNCTION OF LOCALLY PRODUCED 4 TO
6 SECOND PERIOD WIND DRIVEN WAVES. AFTER THE NE-E SURGE WED NITE
INTO THU...PREDOMINATE WIND DRIVEN SIGNIFICANT SEAS WILL BE ON THE
DECLINE. EVENTUALLY... THE ESE 1-2 FOOT GROUND SWELL WILL BECOME
THE DOMINANT SIG. SEAS DRIVER BY LATE THU NIGHT.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 330 AM TUESDAY...A SOMEWHAT RELAXED SFC PG AND A
DISORGANIZED PRESSURE PATTERN VIA LATEST MODEL RUNS INDICATE THAT
MESOSCALE PROCESSES WILL LIKELY CONTROL WINDS FRI INTO SAT. LOOK
FOR AN ACTIVE SEA BREEZE CIRCULATION BOTH DAYS. OVERALL...WINDS
WILL RUN SE-SSW AROUND 10 KT...10-15 KT NEARSHORE DURING THE DAILY
SEA BREEZE. SIGNIFICANT SEAS VIA WAVEWATCH3 AND LOCALLY PRODUCED
SWAN WILL HOVER AROUND 2 FT AND MAINLY BE A FUNCTION OF AN ESE-SE
1-2 FOOT GROUND SWELL. SIG. SEAS COULD POSSIBLY REACH 3 FT
NEARSHORE DUE TO AN INFLUX OF SHORT PERIOD WIND DRIVEN WAVES
DURING THE HEIGHT OF THE AFTN/EARLY EVNG SEA BREEZE CIRCULATION.
&&
.TIDES/COASTAL FLOODING...
AS OF 6 AM TUESDAY...STRONG ASTRONOMICAL TIDES WITH THIS WANING
FULL MOON CYCLE WILL REQUIRE ANOTHER COASTAL FLOOD ADVISORY WITH
TONIGHTS HIGH TIDE FOR THE LOWER CAPE FEAR RIVER SIMILAR TO THE
LAST 3 EVENINGS...BUT LIKELY A FEW INCHES LOWER ON THE PEAK WATER
LEVELS. ELEVATED LEVELS WILL BE OBSERVED ALONG THE BANKS OF THE
ICW AS WELL DURING HIGH TIDE LATE TONIGHT. THE LOWER CAPE FEAR
RIVER WILL EXPERIENCE MINOR COASTAL FLOODING INCLUDING LOCALIZED
AREAS OF DOWNTOWN WILMINGTON. NO COASTAL FLOOD ADVISORIES FOR THE
BEACHES EXPECTED AS ASTRONOMICAL PULLS HAVE ABATED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY FROM 11 PM THIS EVENING TO 2 AM EDT
WEDNESDAY FOR NCZ107.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...DCH
LONG TERM...DCH
AVIATION...DL
TIDES/COASTAL FLOODING...8
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
156 PM EDT TUE AUG 12 2014
.SYNOPSIS...
A COLD FRONT AND UPPER LEVEL TROUGH WILL CROSS THE REGION TODAY.
HIGH PRESSURE WILL BUILD IN THE UPPER MIDWEST ON WEDNESDAY AND THEN
SETTLE OVER THE OHIO VALLEY THURSDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COLD FRONT IS PUSHING EAST ACROSS WESTERN OHIO THIS MORNING AND A
NARROW LINE OF SHOWERS AND THUNDERSTORMS HAS DEVELOPED JUST AHEAD
OF IT ACROSS CENTRAL OHIO. AS WE PROGRESS INTO THIS AFTERNOON...THE
BETTER INSTABILITY AND SHEAR WILL BE JUST OFF TO OUR EAST. THE
LATEST HRRR SEEMS TO HAVE A GOOD HANDLE ON THE CURRENT SITUATION...WITH
THE CURRENT LINE OF STORMS INTENSIFYING AS IT PUSHES EAST OF OUR
AREA INTO THE MORE FAVORABLE AIRMASS LATER THIS MORNING INTO
EARLY AFTERNOON. MEANWHILE...EXPECT SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS TO SPREAD BACK IN FROM THE NORTHWEST
THROUGH THE AFTERNOON HOURS AS THE UPPER LEVEL TROUGH AXIS PIVOTS
INTO THE AREA. THIS WILL LIKELY BE DIURNALLY ENHANCED SO EXPECT
HIGHEST POPS WITH THIS ACROSS OUR NORTHWEST...DECREASING OFF TO
THE SOUTHEAST THROUGH LATE AFTERNOON/EARLY EVENING AS WE START TO
LOSE THE DAYTIME HEATING. EXPECT HIGHS TODAY RANGING FROM THE LOW
TO MID 70S ACROSS THE NORTHWEST TO THE UPPER 70S/NEAR 80 IN THE
FAR SOUTHEAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
ANY SEMBLANCE OF SHOWERS SHOULD BE WELL EAST OF THE CWA BY
NIGHTFALL. WNW WINDS AT THE SURFACE WITH HIGH PRESSURE BUILDING IN
THE MIDWEST WILL HELP DRIER AIR TO BE PULLED INTO THE OHIO VALLEY.
NAM AND CANADIAN MODEL ARE SHOWING A POSSIBILITY OF A SPRINKLE
OVER THE REGION IN THE PREDAWN HOURS WED MORNING. IF THIS WERE TO
OCCUR...IT IS PURELY FROM THE COLD POOL OF AIR ALOFT. ATTM...I DO
NOT SEE ENOUGH MOISTURE TO ALLOW THE COLD POOL TO WRING OUT A
SHOWER AND HAVE LEFT THE FORECAST DRY.
ON WEDNESDAY...NORTHWEST WINDS WILL KEEP THE COLD AIR OVER THE
REGION WITH HIGHS STAYING IN THE LOW TO MID 70S. A WEAK BOUNDARY
WILL LINGER NORTH OF KY AND THE REAL COLD PUSH ON NORTHERLY WINDS
WILL POSSIBLY SQUEEZE OUT A SHOWER WNW TO ESE OF METRO CINCY ON
THURSDAY AFTERNOON...SLOWLY PUSHING SOUTH INTO KY BY EVENING. THE
CENTER OF THE HIGH WILL SETTLE OVER THE CWA BY FRIDAY MORNING AND
LOWS THURSDAY NIGHT WILL DROP DOWN INTO THE LOWER 50S ACROSS THE
AREA.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
NORTHWEST FLOW ALOFT AT THE BEGINNING OF THE PERIOD WILL FLATTEN AND
BECOME MORE ZONAL OVER THE WEEKEND. 12Z MODELS ARE IN REASONABLE
AGREEMENT THAT A SHORT WAVE WILL PUSH INTO THE REGION ON MONDAY. AT
THE SURFACE HIGH PRESSURE WILL DOMINATE LATE IN THE WEEK BEFORE
SLIDING OFF TO THE SOUTHEAST DURING THE WEEKEND. CANNOT COMPLETELY
RULE OUT SOME STORMS ACROSS THE NORTHERN COUNTIES OVER THE WEEKEND
ON THE SOUTHERN FRINGE OF A MORE ACTIVE CONVECTIVE CORRIDOR ACROSS
THE GREAT LAKES. BUT BETTER CHANCE OF SHOWERS AND THUNDERSTORMS ARE
EXPECTED ON MONDAY. TEMPERATURES EARLY IN THE PERIOD WILL BE BELOW
NORMAL BUT THEN WARM TO ABOVE NORMAL EARLY NEXT WEEK.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
COLD FRONT AND ITS ASSOCIATED LINE OF THUNDERSTORMS HAS PUSHED
EAST OF THE EASTERN TAF SITES WITH DRY SLOT NOW WORKING ACROSS
MUCH OF THE AREA. MVFR CLOUDS JUST OFF TO OUR NORTHWEST SHOULD
PIVOT BACK IN ACROSS THE AREA THROUGH THE REMAINDER OF THE
AFTERNOON AS THE UPPER LEVEL TROUGH AXIS APPROACHES. THIS COULD
ALSO LEAD TO SOME SCATTERED SHOWER ACTIVITY ON INTO EARLY EVENING
AND WILL COVER WITH A VCSH. MODELS ARE HANGING ON TO A GOOD DEAL OF
LOW LEVEL MOISTURE THROUGH THE OVERNIGHT SO EXPECT IFR CIGS LATER
TONIGHT ALONG WITH SOME MVFR TO IFR VSBY RESTRICTIONS. LOW CIGS
WILL THEN LINGER INTO THE MORNING HOURS BEFORE GRADUALLY LIFTING
TOWARD THE END OF THE TAF PERIOD.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...JGL
SHORT TERM...FRANKS
LONG TERM...
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
326 PM EDT TUE AUG 12 2014
.SYNOPSIS...
A STRONG FRONTAL SYSTEM WILL CROSS THE AREA TONIGHT. GENERALLY
DRIER AND COOLER CONDITIONS CAN BE EXPECTED FOR THE SECOND HALF OF
THE WEEK. A WARMING TREND WILL SET IN FOR EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
RADAR LIT UP ALL AROUND US...BUT MAINLY SCT SHRA WITH THE HIGHEST
CONCENTRATION IN THE EASTERN HALF OF THE AREA. CIRCULATION EVIDENT
IN THE DC AREA IS CERTAINLY HELPING THE TORRENTIAL RAINFALL THERE.
SO FAR ONLY AN INCH OF RAIN TOTAL HAS FALLEN INTO THE BUCKETS
THERE. THE ENHANCED RAINFALL LOOKS TO BE MOVING TO THE NORTHEAST
AND IT WILL JUST NIP THE SERN COS...SO NO FLOOD WATCH PLANNED AT
THIS TIME PER COORDINATION WITH PHI WOULD PREFER TO HANDLE ANY
LOCAL PROBLEMS WITH STATEMENTS AND ANY APPROPRIATE WARNINGS WHICH
SHOULD BE A LOW PROB EVENT.
THE STORMS FROM THE WEST ARE GETTING VERY CLOSE AND WARNINGS IN OH
ARE OF CONCERN. SPC MESO DISC ISSUED A WHILE AGO CONCERNING GUSTY
WINDS AND LOWER THREAT FOR ROTATION/TORNADOES. BUT THE TEMPS ARE
JUST STARTING TO RISE IN THE FAR WESTERN COS WHERE IT HAS BROKEN
OUT. HIGH STABILITY IN THE EASTERN TWO-THIRDS OF THE AREA WILL
LIKELY SIGNIFICANTLY WEAKEN THIS CONVECTION AS IT MOVES IN.
STILL...THE SHEAR IS HIGHEST IN THE MORE-STABLE PLACES. THE
CONVECTIVE LINE IN WV ON THE EASTERN FRINGE OF THE SUNNIER AREAS
IS PROGGED NICELY BY THE HRRR AND THE EVOLUTION OF THE CURRENT RUN
OF THIS MESO MODEL IS THOUGHT HIGHLY OF. WILL TREND THE NEAR TERM
POPS/PLACEMENT OF CONVECTION TOWARD IT.
ALL GUIDANCE PROGS THE LAST OF THE HEAVIER SHOWERS/STORMS TO BE
PUSHING OFF TO THE E/NE OF THE CWA BY 06Z. SOME WRAP
AROUND/UPSLOPE SHOWERS WILL COME BACK INTO THE NWRN THIRD OF THE
CWA LATER TONIGHT AND LINGER INTO THE MORNING. BUT DRIER AIR AND
GOOD WESTERLY FLOW WILL HELP TO DRY THINGS UP WELL.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
THE MAIN COLD FRONT WILL BE EAST OF THE AREA BY SUNRISE...WITH
THE TRIPLE POINT.
STILL SOME SHOWERS AND STORMS POSSIBLE UNTIL EARLY AFT...UNTIL
THE SECONDARY FRONT MOVES EAST OF THE AREA.
MUCH OF THE AFTERNOON SHOULD BE DRY AND NOT REAL COLD.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
NOT A LOT OF CHANGE FROM YESTERDAY.
THE DEEP UPPER LVL LOW WILL LIKELY BE SLOW TO MOVE OUT BASED
ON 00Z EC LAST NIGHT...TREND THIS SUMMER...AND EXPERIENCE
JET MAX ROTATION AROUND THE UPPER LVL LOW WILL RESULT IN
A CHC OF SHOWERS FOR THU. STILL A CHC FOR FRIDAY...BUT LESS
OF A CHC.
DID KEEP SOME CHC POPS IN FOR SUNDAY...AS 00Z EC SHOWS UPPER
LVL TROUGH DEEPENING MORE. GFS IS FLATTER AND WETTER. ALSO
DECENT WARM ADVECTION.
DID GO DRY SUNDAY NIGHT INTO MONDAY.
SOME CHC OF SHOWERS AND STORMS ON TUE...AS WARM ADVECTION
SETS IN.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
LOW PRESSURE WAVE IN THE MID-ATLANTIC IS ROLLING NORTH AND FRONT
OVER THE OHIO BORDER IS MARCHING STEADILY INTO THE WESTERN
COUNTIES. CIG AND VISBY BOUNCING ALL OVER THE PLACE AS THE
WIDESPREAD SHOWERS GO OVER THE TERMINALS. CURRENTLY A LACK OF VFR
AS IFR IS ALMOST THE RULE. BREAKS IN THE CLOUDS NEAR JST AND BFD
SHOULD GET BIGGER AND ALLOW THE STORMS FROM THE WEST TO MAKE
INROADS TO AT LEAST THOSE TWO SITES. HOWEVER...THE VERY STABLE
LAYER JUST TO THE EAST OF THOSE TERMINALS WILL REDUCE THE CHC OF
TS FOR THE REST OF THE TAF SITES. GUSTY WINDS WOULD BE POSS IN
THESE STORMS. IPT/MDT WILL KEEP THE E/SE WIND THRU ABOUT
06Z WHEN THE FRONT PASSES. RESIDUAL MOISTURE AND CYCLONIC FLOW
SHOULD KEEP IFR CIGS OVER MUCH OF THE AREA TONIGHT. ALSO KEPT A
MENTION OF SHRA/DZ IN THE WEST. DOWNSLOPE SHOULD HELP EAT UP THE
CLOUDS IN THE SERN HALF TO TWO-THIRDS WED MORNING. BUT JST/BFD
WILL STILL HAVE SCT SHRA FOR MOST OF THE TAF CYCLE.
OUTLOOK...
THU...AFTN SHRA NW. OTHERWISE VFR.
FRI-SUN...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LA CORTE/MARTIN
NEAR TERM...DANGELO
SHORT TERM...MARTIN
LONG TERM...MARTIN
AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
256 PM EDT TUE AUG 12 2014
.SYNOPSIS...
A STRONG FRONTAL SYSTEM WILL CROSS THE AREA TONIGHT. GENERALLY
DRIER AND COOLER CONDITIONS CAN BE EXPECTED FOR THE SECOND HALF OF
THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
RADAR LIT UP ALL AROUND US...BUT MAINLY SCT SHRA WITH THE HIGHEST
CONCENTRATION IN THE EASTERN HALF OF THE AREA. CIRCULATION EVIDENT
IN THE DC AREA IS CERTAINLY HELPING THE TORRENTIAL RAINFALL THERE.
SO FAR ONLY AN INCH OF RAIN TOTAL HAS FALLEN INTO THE BUCKETS
THERE. THE ENHANCED RAINFALL LOOKS TO BE MOVING TO THE NORTHEAST
AND IT WILL JUST NIP THE SERN COS...SO NO FLOOD WATCH PLANNED AT
THIS TIME PER COORDINATION WITH PHI WOULD PREFER TO HANDLE ANY
LOCAL PROBLEMS WITH STATEMENTS AND ANY APPROPRIATE WARNINGS WHICH
SHOULD BE A LOW PROB EVENT.
THE STORMS FROM THE WEST ARE GETTING VERY CLOSE AND WARNINGS IN OH
ARE OF CONCERN. SPC MESO DISC ISSUED A WHILE AGO CONCERNING GUSTY
WINDS AND LOWER THREAT FOR ROTATION/TORNADOES. BUT THE TEMPS ARE
JUST STARTING TO RISE IN THE FAR WESTERN COS WHERE IT HAS BROKEN
OUT. HIGH STABILITY IN THE EASTERN TWO-THIRDS OF THE AREA WILL
LIKELY SIGNIFICANTLY WEAKEN THIS CONVECTION AS IT MOVES IN.
STILL...THE SHEAR IS HIGHEST IN THE MORE-STABLE PLACES. THE
CONVECTIVE LINE IN WV ON THE EASTERN FRINGE OF THE SUNNIER AREAS
IS PROGGED NICELY BY THE HRRR AND THE EVOLUTION OF THE CURRENT RUN
OF THIS MESO MODEL IS THOUGHT HIGHLY OF. WILL TREND THE NEAR TERM
POPS/PLACEMENT OF CONVECTION TOWARD IT.
ALL GUIDANCE PROGS THE LAST OF THE HEAVIER SHOWERS/STORMS TO BE
PUSHING OFF TO THE E/NE OF THE CWA BY 06Z. SOME WRAP
AROUND/UPSLOPE SHOWERS WILL COME BACK INTO THE NWRN THIRD OF THE
CWA LATER TONIGHT AND LINGER INTO THE MORNING. BUT DRIER AIR AND
GOOD WESTERLY FLOW WILL HELP TO DRY THINGS UP WELL.
&&
.SHORT TERM /WEDNESDAY/...
THE SURFACE LOW AND FRONTAL SYSTEM WILL BE MOVING AWAY FROM THE
REGION WEDNESDAY...BUT WITH THE LAGGING UPPER TROUGH AND COLD AIR
ALOFT WE WILL SEE AT LEAST SOME SCATTERED SHOWERS...AND EVEN THE
POSSIBILITY OF A RUMBLE OF THUNDER. MID LEVEL LAPSE RATES ARE NOT
PROGGED TO BE PARTICULARLY IMPRESSIVE SO THE THUNDER CHANCES WILL
NOT BE ESPECIALLY HIGH.
IT WILL BE ANOTHER COOLER THAN NORMAL DAY RANGING FROM THE UPPER
60S TO UPPER 70S NW-SE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
MUCH OF THE EXTENDED PERIOD WILL BE DOMINATED BY COOL CYCLONIC
FLOW ALOFT AROUND THE UNSEASONABLY STRONG UPPER LOW/TROUGH THAT
WILL ONLY SLOWLY LIFT THROUGH THE NERN US. THIS SHOULD MEAN A
FAIR AMOUNT OF STRATOCU COOKING UP WITH DAYTIME HEATING AND
PERHAPS A FEW SHOWERS STICKING AROUND INTO THURSDAY.
ENSEMBLES AND THE GFS/ECMWF ALL SHOW UPPER HEIGHTS BEGINNING TO
REBOUND BY THE END OF THE WEEK WITH DRY CONDITIONS FOR FRIDAY AND
SATURDAY. THE DIFFERENCES BEGIN TO ARISE AFTER SATURDAY WITH THE
ECMWF SHOWING A SHARP SHORTWAVE DROPPING DOWN INTO PA FROM NORTH
OF THE LAKES WHILE THE GFS/GEFS INTRODUCE WET WEATHER UNDER A
FLATTER UPPER FLOW IMPLYING WE BECOME VULNERABLE TO CONVECTION
FORMING OVER THE UPPER MIDWEST THAT GETS FUNNELED EAST UNDER THE
MUCH FLATTER UPPER FLOW. GIVEN THE UNCERTAINTY I OPTED FOR A
PRETTY BLAND SMALL MENTION OF SHOWERS THROUGH MONDAY.
FOR THE VERY EXTENDED THE ECMWF SHOWS A RARE...FOR THIS
SUMMER...SURGE IN THE WESTERN ATLANTIC SUBTROPICAL RIDGE WITH 500
MB HEIGHTS EXCEEDING 5900M ALL THE WAY INTO SOUTHERN NEW ENGLAND.
GIVEN THE TENDENCY FOR A TROUGH TO DOMINATE OUR WEATHER MUCH OF
THIS SUMMER...THIS SOLUTION HAS TO BE VIEWED DUBIOUSLY AT THIS
TIME...BUT MAY GIVE HOPE TO REAL SUMMER LOVERS THAT WE COULD HAVE
AT LEAST ONE TRUE HEAT WAVE IN STORE FOR US.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
LOW PRESSURE WAVE IN THE MID-ATLANTIC IS ROLLING NORTH AND FRONT
OVER THE OHIO BORDER IS MARCHING STEADILY INTO THE WESTERN
COUNTIES. CIG AND VISBY BOUNCING ALL OVER THE PLACE AS THE
WIDESPREAD SHOWERS GO OVER THE TERMINALS. CURRENTLY A LACK OF VFR
AS IFR IS ALMOST THE RULE. BREAKS IN THE CLOUDS NEAR JST AND BFD
SHOULD GET BIGGER AND ALLOW THE STORMS FROM THE WEST TO MAKE
INROADS TO AT LEAST THOSE TWO SITES. HOWEVER...THE VERY STABLE
LAYER JUST TO THE EAST OF THOSE TERMINALS WILL REDUCE THE CHC OF
TS FOR THE REST OF THE TAF SITES. GUSTY WINDS WOULD BE POSS IN
THESE STORMS. IPT/MDT WILL KEEP THE E/SE WIND THRU ABOUT
06Z WHEN THE FRONT PASSES. RESIDUAL MOISTURE AND CYCLONIC FLOW
SHOULD KEEP IFR CIGS OVER MUCH OF THE AREA TONIGHT. ALSO KEPT A
MENTION OF SHRA/DZ IN THE WEST. DOWNSLOPE SHOULD HELP EAT UP THE
CLOUDS IN THE SERN HALF TO TWO-THIRDS WED MORNING. BUT JST/BFD
WILL STILL HAVE SCT SHRA FOR MOST OF THE TAF CYCLE.
OUTLOOK...
THU...AFTN SHRA NW. OTHERWISE VFR.
FRI-SUN...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LA CORTE
NEAR TERM...DANGELO
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1249 PM CDT TUE AUG 12 2014
.AVIATION...
LIGHT WINDS AND VFR CONDITIONS WILL CONTINUE THROUGH THE TAF
PERIOD. ISOLATED RW/TRW WILL PRIMARILY REMAIN WEST OF THE KLBB
TERMINAL AS UPPER HIGH BUILDS ACROSS THE REGION.
&&
.PREV DISCUSSION... /ISSUED 350 AM CDT TUE AUG 12 2014/
SHORT TERM...
A FEW LINGERING SHOWERS SHOULD PUSH OUT OF THE FCST AREA BY FCST
VALID TIME AS MODEST UPPER LEVEL JET STREAKS EXITS TO THE EAST FROM
SRN OKLAHOMA. MODELS CONTINUE TO PROG DRIER LOW TO MID LEVEL AIR
ADVECTING INTO THE REGION...AND LOOKING AT WATER VAPOR IMAGERY AND
SFC OBS CANNOT REALLY DISPUTE THAT ATTM. LAST PLACE TO GET THE DRIER
AIR TODAY WILL BE THE SWRN CORNER OF THE FCST AREA WITH THE WRF-NAM
IN PARTICULAR. COULD SEE SOME ISOLATED SHOWERS DEVELOP THIS AFTN AS
THE AIR MASS THERE DESTABILIZES AS THE WRF-NAM AND HRRR SUGGEST.
CONFIDENCE IS LOW AND COVERAGE EXPECTED TO BE LIMITED ATTM SO WILL
KEEP POPS BELOW MENTION BUT WILL BE SOMETHING TO WATCH THROUGH THE
DAY. OTHERWISE TEMPS NOT TOO DIFFERENT THAN SEEN YESTERDAY AND IN
LINE OR JUST A DEGREE OR TWO BELOW MOS LOOKING FINE.
LONG TERM...
MODELS ARE IN GOOD AGREEMENT THROUGH THE END OF THE WEEK INTO THE
BEGINNING OF THE WEEKEND...PERSISTENT UPPER LEVEL RIDGE OVER THE
ROCKIES SLOWLY MIGRATES EASTWARD THROUGH THE WEEK RESULTING IN HIGH
PRESSURE ACROSS WEST TEXAS...BY SATURDAY A NUMBER OF UPPER LEVEL
DISTURBANCES BEGIN TO BREAK THE RIDGE DOWN DUE TO A NUMBER OF
SHORTWAVES EJECTING EASTWARD AND MONSOONAL FLOW OUT OF THE PACIFIC
WEST...GFS/ECMWF BEGIN TO DIVERGE SOMEWHAT ON SATURDAY AT
120HRS...GFS WORKS THE UPPER LEVEL INSTABILITY EASTWARD QUICKER THAN
THE ECMWF WHICH DEVELOPS A CLOSED LOW OVER THE CENTRAL PLAINS
RESULTING IN COLD FRONT EXTENDING FROM CENTRAL KANSAS THROUGH WEST
TEXAS SATURDAY NIGHT INTO SUNDAY WHICH WAS HINTED AT IN PREVIOUS
RUNS...THUS INCREASED POPS SLIGHTLY TOWARD THE END OF THE WEEKEND
MAINTAINING SIMILAR TREND OF PREVIOUS FORECAST...KEPT TEMPS IN NEAR
SEASONAL TO SLIGHTLY COOLER...IF WE STAY DRY TEMPS MAY APPROACH THE
100S OFF THE CAPROCK BY THE END OF THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 61 90 64 90 64 / 10 10 0 0 10
TULIA 62 91 65 92 66 / 0 0 0 0 10
PLAINVIEW 62 91 65 91 66 / 0 0 0 0 10
LEVELLAND 64 91 66 92 66 / 0 0 0 0 10
LUBBOCK 65 93 69 93 67 / 0 0 0 0 10
DENVER CITY 64 92 66 92 66 / 10 0 0 0 10
BROWNFIELD 65 92 67 93 66 / 0 0 0 0 10
CHILDRESS 67 95 70 97 71 / 0 0 0 0 10
SPUR 65 94 68 95 70 / 0 0 0 0 10
ASPERMONT 67 96 70 96 71 / 0 0 0 0 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
06/99/99