Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/02/15
AREA FORECAST DISCUSSION
NWS TUCSON AZ
905 PM MST SUN AUG 30 2015
.SYNOPSIS...ANOTHER GOOD CHANCE OF SHOWERS AND THUNDERSTORMS ON
MONDAY. A SLOW DRYING TREND WILL THEN LIMIT THUNDERSTORMS TO EAST OF
TUCSON THE SECOND HALF OF THE WEEK. HOTTER THAN AVERAGE TEMPERATURES
WILL FALL TO NEAR AVERAGE AROUND THE MIDDLE OF THE WEEK.
&&
.DISCUSSION...WIDELY SCATTERED SHOWERS AND THUNDERSTORMS THIS
AFTERNOON INTO THE EARLY EVENING HOURS. OUTFLOW FROM STORMS IN
CENTRAL PIMA COUNTY SENT NW-N INTO MARICOPA COUNTY ALONG COMBINED
WITH WEAK UPPER LEVEL DYNAMICS TO GENERATE NEW THUNDERSTORMS IN
MARICOPA COUNTY WITHIN IN PAST 1-2 HRS. MOST OF THIS ACTIVITY IS
SLOWLY MOVING TO THE EAST. NEW 00Z RUN OF THE UOFA WRF NAM ALONG
WITH 02Z HRRR RUN MOVES THIS AREA OF SHOWERS/STORMS ACROSS SE PINAL
COUNTY AND THE NORTHERN PARTS OF THE TUCSON METRO AREA BEFORE
DIMINISHING AFTER MIDNIGHT. RAN OUT A QUICK UPDATE TO THE FORECAST
LAST HOUR TO ACCOUNT FOR THIS THINKING. OTHERWISE MOST OF THE
FORECAST AREA WILL REMAIN DRY DURING THE OVERNIGHT HOURS.
EASTERN HALF OF THE FORECAST AREA WILL BE THE FOCUS OF STORMS MONDAY
AFTERNOON AND EVENING.
&&
.AVIATION...VALID THRU 01/00Z.
WDLY SCTD -SHRA/ISOLD TS N-NW OF KTUS THRU 31/10Z...OTRW DECREASING
DEBRIS CLOUDS THRU 31/16Z. AFT 31/18Z SCTD SHRA/TSRA DVLPG. BRIEF
MVFR CONDS AND GUSTY WINDS TO 45 KTS WILL BE PSBL IN AND AROUND THE
STRONGER STORMS. OUTSIDE OF THUNDERSTORM INFLUENCE SURFACE WINDS
WILL GENERALLY BE UNDER 10 KTS. AVIATION DISCUSSION NOT UPDATED FOR
TAF AMENDMENTS.
&&
.FIRE WEATHER...ISOLATED SHOWERS MAINLY NW OF TUCSON INTO EARLY
MONDAY MORNING. ON MONDAY THUNDERSTORMS WILL TEND TO BE MORE FOCUSED
OVER EASTERN ZONES...WITH DIMINISHED THUNDERSTORM ACTIVITY FROM
WEDNESDAY ON. THUNDERSTORMS ARE EXPECTED TO BE WET AND AS IS TYPICAL
MAY PRODUCE STRONG...GUSTY AND ERRATIC WINDS WITH THE STRONGER
THUNDERSTORMS. OUTSIDE OF THUNDERSTORMS GENERALLY LIGHT TERRAIN
DRIVEN WINDS ARE EXPECTED. BEGINNING MONDAY A WEST TO SOUTHWEST FLOW
WILL DEVELOP ACROSS ARIZONA. THE STRONGEST WINDS WILL BE ACROSS ZONE
150...PEAKING IN THE 15-20 MPH RANGE.
&&
.CLIMATE...RECORD SETTING DAY FOR TUCSON AIRPORT AS IT RECORDED THE
82ND CONSECUTIVE DAY IN WHICH THE LOW TEMPERATURE WAS 70 DEGREES OR
WARMER. THE PREVIOUS RECORD WAS 81 DAYS WHICH OCCURRED JUST TWO
YEARS AGO. UNLESS THE AIRPORT GETS HIT WITH A STRONG THUNDERSTORM
THIS RECORD WILL LIKELY CONTINUE TO ADD UP DAYS INTO NEXT WEEKEND.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
852 PM EDT TUE SEP 1 2015
.Near Term [Through Tonight]...
The remnants of Erika continue to bring rain to mainly the Big
Bend area. Based on radar trends, have cut back slightly on PoPs
across some of the marine zones but will have to expand the
mention of activity into some of the western portions of the CWA.
Besides some tweaks to PoPs, temperatures are on track.
&&
.Aviation...
[Through 00Z Thursday]...
Convective activity has been diminishing across the TAF sites this
evening and thus have left the mention out of SHRA/TSRA for the
remainder of the night at most sites. Will need to watch TLH and VAD
though.This activity should increase again on Wendesday in the late
morning into the afternoon across the eastern half of the TAF sites.
While overall VFR conditions are forecast, except for a brief
decrease in VSBY possible in convective activity, MVFR fog and LIFR
cigs are forecast for VLD for the morning.
&&
.Prev Discussion [345 PM EDT]...
.Short Term [Wednesday Through Thursday Night]...
Above-average rain chances will persist through Wednesday, at least
across the FL Big Bend, south-central GA, and north FL, as the
remnants of Erika translate slowly northward. PoPs will range from
20% around Dothan and Panama City, where the airmass remains
considerably drier, to 70% around Valdosta, Madison, and Perry.
Scattered mainly afternoon and evening thunderstorms are expected
Thursday region-wide. Our PoP is 40% for much of the area, which is
only slightly above climo. This number may trend up a bit in
subsequent forecasts as there may be some additional Q-G forcing mid-
upper layer trough approaches from the west. Temperatures will be
seasonably warm this period, with highs in the lower 90s and lows in
the 70s.
.Long Term [Friday Through Tuesday]...
The 12z GFS and ECMWF are in better agreement than 24 hours ago, as
they forecast a broad area of lower 500 mb heights over our region
for much of this period. PoPs will be slightly above-average (40-
50%) through the weekend, then tail off a bit next week as slightly
drier air in the boundary layer advects into the region on the
western flank of a weak low pressure system off the Southeast coast.
Temperatures will remain near average, with lows in the 70s and
highs near 90.
.Marine...
We were fortunate enough to get a 1630 UTC ASCAT pass over our
marine area to augment our sparse observation network. The data
showed that the remnants of Erika, though weak in terms of pressure,
had a closed circulation with wind speeds at advisory levels across
portions of the northeast Gulf of Mexico. The 15 UTC HRRR appeared
to have the best handle on this system (based on its
initialization), so we weighted it more in our forecast for
overnight. Convection aside, we expect "exercise caution" winds in
Apalachee Bay tonight, then winds weakening Wednesday morning as the
center of the low moves inland. Afterwards, winds and seas will be
quite low.
.Fire Weather...
Relative humidity values will remain in the upper 40s or higher
through Thursday. In addition, winds are forecast to remain less
than 10MPH and thus hazardous fire weather conditions are not
expected through Thursday.
.Hydrology...
The heaviest and most organized rain is expected across portions of
the FL Big Bend from this evening through Wednesday. Rain amounts
will be around an inch east and south of Tallahassee, and less than
a quarter of an inch elsewhere. Isolated rain amounts up to 4 inches
are possible, which could cause localized flooding if it occurs in
the wrong place (i.e. urban areas, small streams, etc.). Our rivers
were all below their local action stages, and the latest hydrologic
ensembles forecast this to continue for the next several days.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 74 91 74 93 75 / 50 60 30 40 30
Panama City 76 88 77 88 76 / 10 30 10 40 30
Dothan 73 93 73 92 73 / 0 20 10 40 30
Albany 74 92 74 93 74 / 10 40 10 40 20
Valdosta 74 90 73 92 74 / 40 70 30 40 30
Cross City 75 90 74 91 75 / 60 50 30 40 30
Apalachicola 75 89 77 90 77 / 30 40 20 40 30
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK until Midnight EDT tonight FOR Coastal
Franklin.
GA...NONE.
AL...NONE.
GM...NONE.
&&
$$
NEAR TERM...FIEUX
SHORT TERM...FOURNIER
LONG TERM...FOURNIER
AVIATION...FIEUX
MARINE...FOURNIER
FIRE WEATHER...FIEUX
HYDROLOGY...FOURNIER
AREA FORECAST DISCUSSION
NWS MIAMI FL
800 PM EDT TUE SEP 1 2015
.UPDATE...
SHOWERS AND THUNDERSTORMS CONTINUE TO DECREASE IN COVERAGE ACROSS
THE AREA EARLY THIS EVENING WITH HEATING LOSS. LATEST HRRR KEEPS
ONLY ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ACROSS MAINLY
THE ATLANTIC AND GULF WATERS THROUGH THE OVERNIGHT HOURS. UPDATED
FORECAST TO ADJUST FOR THESE TRENDS.
&&
.PREV DISCUSSION... /ISSUED 743 PM EDT TUE SEP 1 2015/
AVIATION...
VFR OVERNIGHT. OUTFLOW BOUNDARY WHICH MOVED DUE EAST LATE THIS
AFTERNOON GENERATED A FEW WIND GUSTS AND SOME BRIEF MVFR CIGS
WHICH WILL DISSIPATE THIS EVENING. REGIME IS SIMILAR TOMORROW,
WITH SEABREEZES ON BOTH COASTS AND STORMS FOCUSED OVER THE
INTERIOR. EAST COAST TERMINALS, POSSIBLY WITH THE EXCEPTION OF TMB
AND PBI, MAY STAY DRY AGAIN. WITH THE GULF BREEZE FADING, STORMS
JUST EAST OF APF MAY CROSS THAT TERMINAL IN THE NEAR TERM TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 78 92 78 92 / 10 20 20 30
FORT LAUDERDALE 80 91 79 92 / 10 30 20 20
MIAMI 80 92 78 92 / 10 40 20 20
NAPLES 77 91 77 90 / 10 40 40 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
UPDATE...10/CD
AVIATION...21/KM
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
901 AM EDT MON AUG 31 2015
.DISCUSSION...
...FLOOD WATCH CONTINUES AREAWIDE THROUGH EARLY THIS EVENING...
CURRENT-TONIGHT...MORNING 915MHZ CAPE PROFILES SHOW DEEP SSE/S FLOW
FROM THE SURFACE THROUGH 10.0KFT. KXMR SOUNDING PROFILE SHOWS MID-
LEVEL TEMPERATURES (700/500MB, +9.0C/-7.8C) RESPECTIVELY WITH A
PRECIPITABLE WATER VALUE OF 2.07 INCHES.
AN INVERTED SURFACE TROUGH IS STILL DEPICTED IN THE EASTERN GULF AND
IS FORECAST TO PUSH VERY SLOWLY WESTWARD AWAY FROM THE FLORIDA
PENINSULA OVER THE NEXT 24 HOURS. THIS WILL ALLOW THE ATLANTIC RIDGE
TO GRADUALLY BUILD EASTWARD TOWARD ECFL. THE GFS POOLS DEEPER
PRECIPITABLE WATER VALUES ACROSS NORTH/NORTH CENTRAL FLORIDA UP TO
2.40 INCHES. MOISTURE VALUES TAPER DOWN THROUGH THE TREASURE COAST.
THE EAST COAST SEA BREEZE BOUNDARY WILL DEVELOP BY EARLY AFTERNOON
AND PUSH SLOWLY INLAND. EXPECT INITIAL SHOWERS/STORMS TO FORM ALONG
THIS BOUNDARY AND JUST INLAND WITH COVERAGE INCREASING THROUGH LATE
DAY AND INCREASING NORTH/WEST FROM THE TREASURE COAST. WILL KEEP 60
TO 70 PERCENT POPS ALONG THE I-4 CORRIDOR AND TAPER DOWN TO AROUND
40 TO 50 PERCENT ALONG THE IMMEDIATE MARTIN COUNTY COAST AND THIS
HERE COULD STILL BE A BIT HIGH. THE LOCAL HRRR MODEL ALSO SUGGESTS
STRONGER STORMS/HIGHER COVERAGE INLAND/NORTH TODAY WITH ADDITIONAL
BOUNDARY MERGERS AND DEEPER MOISTURE HERE.
HEAVY RAINFALL...FREQUENT LIGHTNING AND GUSTY WINDS TO AROUND 45 MPH
WILL CONTINUE AS THREATS. HEAVY RAINFALL COULD LEAD TO PONDING OF
WATER ON ROADWAYS AND NUISANCE FLOODING IN LOW-LYING AREAS AS WELL
AS ANYWHERE ELSE WHERE ABUNDANT RAINFALL HAS OCCURRED OVER RECENT
DAYS. CELL MOVEMENT WILL BE MAINLY FROM THE SOUTH TO THE NORTH AT
AROUND 20 MPH.
&&
.AVIATION...DEEP SOUTHERLY MOIST FLOW WITH NUMEROUS SHOWERS AND
SCATTERED STORMS THIS AFTERNOON/EARLY EVENING. VCTS MAINLY AFT 18Z
WITH ASSOC TEMPO GROUPS. TEMPO IFR/MVFR CIGS/VSBYS IN SCT-NMRS
CONVECTION. SEA BREEZE/MESOSCALE BOUNDARY COLLISIONS WILL AID TO
INCREASE COVERAGE LATE IN THE DAY. DIURNAL ACTIVITY WILL DECREASE IN
COVERAGE/INTENSITY THROUGH THE EVENING WITH MAINLY DRY CONDS
OVERNIGHT.
&&
.MARINE...TODAY-TONIGHT...CAUTIONARY STATEMENTS LIKELY TO BE DROPPED
FOR OFFSHORE ZONES FOR THE 10AM/14Z CWF ISSUANCE AS BOTH WINDS/SEAS
CONTINUE TO DECREASE/SUBSIDE. PERSISTENT LONG PERIOD SWELL CONTINUES
OVER THE WATERS. S/SSE WINDS DECREASING TO 10-15 KTS INTO THE
AFTERNOON AND AROUND 10 KTS OR LESS THROUGH THE EVENING/OVERNIGHT.
SEAS FALLING TO 3-5 FT THRU THE AFTN AND 3-4 FT TONIGHT.
THERE WILL BE A HIGHER COVERAGE OF STORMS NORTH OF THE CAPE WITH
LOWER (POSSIBLY MUCH LOWER) COVERAGE OVER THE TREASURE COAST WATERS.
STORM MOTION WILL BE OUT OF THE SOUTH TO SOUTH-SOUTHWEST SO SOME
STORMS NEAR THE COAST...ALONG THE EAST COAST SEA BREEZE...MAY PUSH
ACROSS INTRACOASTAL/NEAR SHORE ATLC WATERS THIS AFTERNOON/EARLY
EVENING.
&&
.HYDROLOGY...SHINGLE CREEK AT CAMPBELL (SHIF1) REMAINS WITHIN 0.78
FOOT OF FLOOD STAGE. FORTUNATELY LITTLE IF ANY RAINFALL OCCURRED
OVER THE BASIN OVERNIGHT BUT WILL NEED TO WATCH FOR PERSISTENT
RAINFALL OVER THE BASIN THIS AFTERNOON AND EARLY EVENING.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...FLOOD WATCH THROUGH THIS EVENING FOR COASTAL VOLUSIA COUNTY-
INDIAN RIVER-INLAND VOLUSIA COUNTY-MARTIN-NORTHERN BREVARD
COUNTY-NORTHERN LAKE COUNTY-OKEECHOBEE-ORANGE-OSCEOLA-
SEMINOLE-SOUTHERN BREVARD COUNTY-SOUTHERN LAKE COUNTY-ST.
LUCIE.
AM...NONE.
&&
$$
FORECASTS...SEDLOCK
IMPACT WEATHER...VOLKMER/LASCODY
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1253 PM CDT MON AUG 31 2015
.UPDATE...
ISSUED AT 1049 AM CDT MON AUG 31 2015
WEAK REMNANTS OF THE BOUNDARY IN THE REGION FROM YESTERDAY
PROVIDING JUST ENOUGH OF A FOCUS FOR SHOWERS AND THUNDERSTORMS
THIS MORNING. SOME INTENSE PRECIPITATION RATES COMBINED WITH
A LACK OF SIGNIFICANT STORM MOTION HAS RESULTED IN HIGH RAINFALL
TOTALS UNDER THE NEARLY STATIONARY STORMS. HAVE HAD TO SENT OUT
UPDATES FOR PRECIP IN THE SOUTHEAST. ENOUGH GAPS IN THE CLOUD
COVER OVER THE SE THAT NO RUSH TO KNOCK DOWN THE MAX TEMPS FOR
TODAY...BUT WILL KEEP AN EYE ON THE AREA. OTHERWISE, A WARM A
MUGGY DAY FOR CENTRAL ILLINOIS.
&&
.SHORT TERM...(TODAY)
ISSUED AT 317 AM CDT MON AUG 31 2015
08Z/3AM SURFACE ANALYSIS SHOWS DISSIPATING FRONTAL BOUNDARY
EXTENDING FROM NORTHERN INDIANA INTO CENTRAL ILLINOIS...GENERALLY
ALONG A FORT WAYNE TO QUINCY LINE. AS WAS THE CASE LAST
NIGHT...QUITE A BIT OF FOG IS DEVELOPING ALONG/NORTH OF THE BOUNDARY
WHERE WINDS ARE NEARLY CALM AND LOW-LEVEL MOISTURE IS ABUNDANT.
LATEST OBS SHOW LOWEST VISBYS CONCENTRATED ALONG THE SOUTHERN SHORE
OF LAKE MICHIGAN ACROSS NORTHERN INDIANA INTO THE CHICAGO AREA.
HRRR HAS BEEN CONSISTENTLY SPREADING THIS THICKER FOG W/SW ALONG THE
FRONT INTO THE NORTHERN KILX CWA OVER THE NEXT COUPLE HOURS...AND AM
BEGINNING TO SEE THIS UNFOLDING WITH VISBY NOW DOWN TO 1/4SM AS FAR
SW AS KIKK. FOLLOWING THE HRRR TREND...WILL MENTION AREAS OF DENSE
FOG ALONG/NORTHEAST OF A GALESBURG TO BLOOMINGTON-NORMAL LINE EARLY
THIS MORNING...WITH PATCHY/AREAS OF FOG ELSEWHERE AROUND THE AREA.
HIGH-RES MODELS SUCH AS THE HRRR AND RAPID REFRESH ARE SUGGESTING
THAT ISOLATED CONVECTION MAY DEVELOP ACROSS SOUTHEAST ILLINOIS OVER
THE NEXT COUPLE OF HOURS. LATEST RADAR IMAGERY IS CLEAR...HOWEVER
SCATTERED MID-LEVEL CLOUDS ARE BEGINNING TO DEVELOP ON IR SATELLITE
IMAGERY ALONG/SOUTH OF I-70...SO HAVE OPTED TO CARRY SLIGHT CHANCE
POPS HERE EARLY THIS MORNING. LATEST WATER VAPOR IMAGERY SHOWS A
SMALL BUT VIGOROUS SHORT-WAVE DROPPING SOUTHWESTWARD FROM NORTHEAST
INDIANA. THIS FEATURE WILL LIKELY INTERACT WITH THE DECAYING FRONT
TO TRIGGER ISOLATED CONVECTION FURTHER NORTH INTO THE CWA THIS
AFTERNOON. MOST MODELS ARE HINTING AT LEAST SOME QPF ACROSS THE
SOUTHERN TWO-THIRDS OF THE AREA...SO HAVE ADDED SLIGHT CHANCE POPS
ALONG/SOUTH OF A JACKSONVILLE TO BLOOMINGTON-NORMAL LINE FOR THE
AFTERNOON.
.LONG TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 317 AM CDT MON AUG 31 2015
MAIN WEATHER STORY THROUGH THE EXTENDED WILL BE THE VERY WARM AND
HUMID CONDITIONS THAT ARE EXPECTED TO PERSIST THROUGH EARLY NEXT
WEEK. HIGH TEMPERATURES ON TUESDAY WILL REACH THE UPPER 80S TO
AROUND 90 DEGREES...THEN READINGS WILL CLIMB INTO THE LOWER 90S FOR
THE REMAINDER OF THE PERIOD. DRY WEATHER WILL GENERALLY BE THE
RULE...HOWEVER ISOLATED CONVECTION CANNOT BE RULED OUT...ESPECIALLY
TUESDAY AFTERNOON AS A WEAKNESS IN THE MEAN 500MB RIDGE AXIS REMAINS
IN THE VICINITY. MODELS ARE HINTING AT SOME QPF ACROSS THE E/NE CWA
AS THIS FEATURE GRADUALLY SHIFTS INTO THE GREAT LAKES BY WEDNESDAY.
THE NEXT SIGNIFICANT CHANCE FOR RAIN WILL NOT ARRIVE UNTIL EARLY
NEXT WEEK...WHEN A STRONG SHORT-WAVE FLATTENS THE UPPER RIDGE AND
PUSHES A COLD FRONT INTO THE REGION. MODELS ARE IN DISAGREEMENT
CONCERNING THE SPEED OF THIS PROCESS...WITH THE GFS BEING ABOUT 24
HOURS FASTER THAN THE ECMWF/GEM. THE 00Z AUG 31 GFS SHOWS THE COLD
FRONT PASSING THROUGH CENTRAL ILLINOIS LATE SUNDAY NIGHT INTO
MONDAY...WHILE THE ECMWF/GEM HAVE DELAYED FROPA UNTIL LATE MONDAY
NIGHT INTO TUESDAY. GIVEN PERSISTENT AND HIGHLY AMPLIFIED RIDGE
POSITIONED ACROSS THE MIDWEST...THINK A SLOWER BREAK DOWN TO THE
PATTERN IS PRUDENT. HAVE THEREFORE TRENDED THE FORECAST TOWARD THE
SLOWER ECMWF/GEM CONSENSUS. AS A RESULT...AM EXPECTING DRY
CONDITIONS THROUGH SUNDAY NIGHT...WITH HIGHER RAIN CHANCES ARRIVING
BY LATE MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1235 PM CDT MON AUG 31 2015
CU FIELD AND SOME CIRRUS TODAY WITH THE CIGS LINGERING AT THE
MVFR/VFR BREAK. PIA MORE LIKELY TO BE IN THE SCT TERRITORY, AND A
COLD POOL FROM THIS MORNINGS CONVECTION IN THE SOUTHEAST HAS
SCOURED OUT THE VERTICAL GROWTH FOR CMI. LIGHT SOUTHERLY WINDS
OVERNIGHT, VEERING TO MORE SOUTHWESTERLY BY MORNING. BIGGER ISSUE
FOR THE OVERNIGHT WILL BE THE POTENTIAL FOR FOG DEVELOPMENT.
ALTHOUGH LAST NIGHT WAS MORE SCATTERED, DEWPOINTS ARE IN THE LOWER
70S, SEVERAL DEGREES ABOVE THIS TIME YESTERDAY IN MANY LOCATIONS.
HAVE DROPPED TEMPO TO 1SM FOR NOW KEEPING IT TO IFR PREDAWN.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...HJS
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1100 AM CDT MON AUG 31 2015
.UPDATE...
ISSUED AT 1049 AM CDT MON AUG 31 2015
WEAK REMNANTS OF THE BOUNDARY IN THE REGION FROM YESTERDAY
PROVIDING JUST ENOUGH OF A FOCUS FOR SHOWERS AND THUNDERSTORMS
THIS MORNING. SOME INTENSE PRECIPITATION RATES COMBINED WITH
A LACK OF SIGNIFICANT STORM MOTION HAS RESULTED IN HIGH RAINFALL
TOTALS UNDER THE NEARLY STATIONARY STORMS. HAVE HAD TO SENT OUT
UPDATES FOR PRECIP IN THE SOUTHEAST. ENOUGH GAPS IN THE CLOUD
COVER OVER THE SE THAT NO RUSH TO KNOCK DOWN THE MAX TEMPS FOR
TODAY...BUT WILL KEEP AN EYE ON THE AREA. OTHERWISE, A WARM A
MUGGY DAY FOR CENTRAL ILLINOIS.
&&
.SHORT TERM...(TODAY)
ISSUED AT 317 AM CDT MON AUG 31 2015
08Z/3AM SURFACE ANALYSIS SHOWS DISSIPATING FRONTAL BOUNDARY
EXTENDING FROM NORTHERN INDIANA INTO CENTRAL ILLINOIS...GENERALLY
ALONG A FORT WAYNE TO QUINCY LINE. AS WAS THE CASE LAST
NIGHT...QUITE A BIT OF FOG IS DEVELOPING ALONG/NORTH OF THE BOUNDARY
WHERE WINDS ARE NEARLY CALM AND LOW-LEVEL MOISTURE IS ABUNDANT.
LATEST OBS SHOW LOWEST VISBYS CONCENTRATED ALONG THE SOUTHERN SHORE
OF LAKE MICHIGAN ACROSS NORTHERN INDIANA INTO THE CHICAGO AREA.
HRRR HAS BEEN CONSISTENTLY SPREADING THIS THICKER FOG W/SW ALONG THE
FRONT INTO THE NORTHERN KILX CWA OVER THE NEXT COUPLE HOURS...AND AM
BEGINNING TO SEE THIS UNFOLDING WITH VISBY NOW DOWN TO 1/4SM AS FAR
SW AS KIKK. FOLLOWING THE HRRR TREND...WILL MENTION AREAS OF DENSE
FOG ALONG/NORTHEAST OF A GALESBURG TO BLOOMINGTON-NORMAL LINE EARLY
THIS MORNING...WITH PATCHY/AREAS OF FOG ELSEWHERE AROUND THE AREA.
HIGH-RES MODELS SUCH AS THE HRRR AND RAPID REFRESH ARE SUGGESTING
THAT ISOLATED CONVECTION MAY DEVELOP ACROSS SOUTHEAST ILLINOIS OVER
THE NEXT COUPLE OF HOURS. LATEST RADAR IMAGERY IS CLEAR...HOWEVER
SCATTERED MID-LEVEL CLOUDS ARE BEGINNING TO DEVELOP ON IR SATELLITE
IMAGERY ALONG/SOUTH OF I-70...SO HAVE OPTED TO CARRY SLIGHT CHANCE
POPS HERE EARLY THIS MORNING. LATEST WATER VAPOR IMAGERY SHOWS A
SMALL BUT VIGOROUS SHORT-WAVE DROPPING SOUTHWESTWARD FROM NORTHEAST
INDIANA. THIS FEATURE WILL LIKELY INTERACT WITH THE DECAYING FRONT
TO TRIGGER ISOLATED CONVECTION FURTHER NORTH INTO THE CWA THIS
AFTERNOON. MOST MODELS ARE HINTING AT LEAST SOME QPF ACROSS THE
SOUTHERN TWO-THIRDS OF THE AREA...SO HAVE ADDED SLIGHT CHANCE POPS
ALONG/SOUTH OF A JACKSONVILLE TO BLOOMINGTON-NORMAL LINE FOR THE
AFTERNOON.
.LONG TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 317 AM CDT MON AUG 31 2015
MAIN WEATHER STORY THROUGH THE EXTENDED WILL BE THE VERY WARM AND
HUMID CONDITIONS THAT ARE EXPECTED TO PERSIST THROUGH EARLY NEXT
WEEK. HIGH TEMPERATURES ON TUESDAY WILL REACH THE UPPER 80S TO
AROUND 90 DEGREES...THEN READINGS WILL CLIMB INTO THE LOWER 90S FOR
THE REMAINDER OF THE PERIOD. DRY WEATHER WILL GENERALLY BE THE
RULE...HOWEVER ISOLATED CONVECTION CANNOT BE RULED OUT...ESPECIALLY
TUESDAY AFTERNOON AS A WEAKNESS IN THE MEAN 500MB RIDGE AXIS REMAINS
IN THE VICINITY. MODELS ARE HINTING AT SOME QPF ACROSS THE E/NE CWA
AS THIS FEATURE GRADUALLY SHIFTS INTO THE GREAT LAKES BY WEDNESDAY.
THE NEXT SIGNIFICANT CHANCE FOR RAIN WILL NOT ARRIVE UNTIL EARLY
NEXT WEEK...WHEN A STRONG SHORT-WAVE FLATTENS THE UPPER RIDGE AND
PUSHES A COLD FRONT INTO THE REGION. MODELS ARE IN DISAGREEMENT
CONCERNING THE SPEED OF THIS PROCESS...WITH THE GFS BEING ABOUT 24
HOURS FASTER THAN THE ECMWF/GEM. THE 00Z AUG 31 GFS SHOWS THE COLD
FRONT PASSING THROUGH CENTRAL ILLINOIS LATE SUNDAY NIGHT INTO
MONDAY...WHILE THE ECMWF/GEM HAVE DELAYED FROPA UNTIL LATE MONDAY
NIGHT INTO TUESDAY. GIVEN PERSISTENT AND HIGHLY AMPLIFIED RIDGE
POSITIONED ACROSS THE MIDWEST...THINK A SLOWER BREAK DOWN TO THE
PATTERN IS PRUDENT. HAVE THEREFORE TRENDED THE FORECAST TOWARD THE
SLOWER ECMWF/GEM CONSENSUS. AS A RESULT...AM EXPECTING DRY
CONDITIONS THROUGH SUNDAY NIGHT...WITH HIGHER RAIN CHANCES ARRIVING
BY LATE MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 653 AM CDT MON AUG 31 2015
ASIDE FROM SOME EARLY MORNING IFR/MVFR FOG TODAY AND AGAIN LATE
TONIGHT, PREDOMINANTLY VFR CONDITIONS EXPECTED ACROSS THE CENTRAL
ILLINOIS TERMINALS THROUGH THE 12Z TAF VALID TIME. DIURNALLY
DRIVEN CU WILL POP THIS MORNING, WITH ISOLATED SHOWER/STORMS
POSSIBLY DEVELOPING. HOWEVER, SHOWER/STORM COVERAGE IS EXPECTED TO
BE TOO LOW TO MENTION AT THIS TIME. WINDS SHOULD CONTINUE TO BE
LIGHT OVERALL.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HJS
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS LINCOLN IL
659 AM CDT MON AUG 31 2015
.SHORT TERM...(TODAY)
ISSUED AT 317 AM CDT MON AUG 31 2015
08Z/3AM SURFACE ANALYSIS SHOWS DISSIPATING FRONTAL BOUNDARY
EXTENDING FROM NORTHERN INDIANA INTO CENTRAL ILLINOIS...GENERALLY
ALONG A FORT WAYNE TO QUINCY LINE. AS WAS THE CASE LAST
NIGHT...QUITE A BIT OF FOG IS DEVELOPING ALONG/NORTH OF THE BOUNDARY
WHERE WINDS ARE NEARLY CALM AND LOW-LEVEL MOISTURE IS ABUNDANT.
LATEST OBS SHOW LOWEST VISBYS CONCENTRATED ALONG THE SOUTHERN SHORE
OF LAKE MICHIGAN ACROSS NORTHERN INDIANA INTO THE CHICAGO AREA.
HRRR HAS BEEN CONSISTENTLY SPREADING THIS THICKER FOG W/SW ALONG THE
FRONT INTO THE NORTHERN KILX CWA OVER THE NEXT COUPLE HOURS...AND AM
BEGINNING TO SEE THIS UNFOLDING WITH VISBY NOW DOWN TO 1/4SM AS FAR
SW AS KIKK. FOLLOWING THE HRRR TREND...WILL MENTION AREAS OF DENSE
FOG ALONG/NORTHEAST OF A GALESBURG TO BLOOMINGTON-NORMAL LINE EARLY
THIS MORNING...WITH PATCHY/AREAS OF FOG ELSEWHERE AROUND THE AREA.
HIGH-RES MODELS SUCH AS THE HRRR AND RAPID REFRESH ARE SUGGESTING
THAT ISOLATED CONVECTION MAY DEVELOP ACROSS SOUTHEAST ILLINOIS OVER
THE NEXT COUPLE OF HOURS. LATEST RADAR IMAGERY IS CLEAR...HOWEVER
SCATTERED MID-LEVEL CLOUDS ARE BEGINNING TO DEVELOP ON IR SATELLITE
IMAGERY ALONG/SOUTH OF I-70...SO HAVE OPTED TO CARRY SLIGHT CHANCE
POPS HERE EARLY THIS MORNING. LATEST WATER VAPOR IMAGERY SHOWS A
SMALL BUT VIGOROUS SHORT-WAVE DROPPING SOUTHWESTWARD FROM NORTHEAST
INDIANA. THIS FEATURE WILL LIKELY INTERACT WITH THE DECAYING FRONT
TO TRIGGER ISOLATED CONVECTION FURTHER NORTH INTO THE CWA THIS
AFTERNOON. MOST MODELS ARE HINTING AT LEAST SOME QPF ACROSS THE
SOUTHERN TWO-THIRDS OF THE AREA...SO HAVE ADDED SLIGHT CHANCE POPS
ALONG/SOUTH OF A JACKSONVILLE TO BLOOMINGTON-NORMAL LINE FOR THE
AFTERNOON.
.LONG TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 317 AM CDT MON AUG 31 2015
MAIN WEATHER STORY THROUGH THE EXTENDED WILL BE THE VERY WARM AND
HUMID CONDITIONS THAT ARE EXPECTED TO PERSIST THROUGH EARLY NEXT
WEEK. HIGH TEMPERATURES ON TUESDAY WILL REACH THE UPPER 80S TO
AROUND 90 DEGREES...THEN READINGS WILL CLIMB INTO THE LOWER 90S FOR
THE REMAINDER OF THE PERIOD. DRY WEATHER WILL GENERALLY BE THE
RULE...HOWEVER ISOLATED CONVECTION CANNOT BE RULED OUT...ESPECIALLY
TUESDAY AFTERNOON AS A WEAKNESS IN THE MEAN 500MB RIDGE AXIS REMAINS
IN THE VICINITY. MODELS ARE HINTING AT SOME QPF ACROSS THE E/NE CWA
AS THIS FEATURE GRADUALLY SHIFTS INTO THE GREAT LAKES BY WEDNESDAY.
THE NEXT SIGNIFICANT CHANCE FOR RAIN WILL NOT ARRIVE UNTIL EARLY
NEXT WEEK...WHEN A STRONG SHORT-WAVE FLATTENS THE UPPER RIDGE AND
PUSHES A COLD FRONT INTO THE REGION. MODELS ARE IN DISAGREEMENT
CONCERNING THE SPEED OF THIS PROCESS...WITH THE GFS BEING ABOUT 24
HOURS FASTER THAN THE ECMWF/GEM. THE 00Z AUG 31 GFS SHOWS THE COLD
FRONT PASSING THROUGH CENTRAL ILLINOIS LATE SUNDAY NIGHT INTO
MONDAY...WHILE THE ECMWF/GEM HAVE DELAYED FROPA UNTIL LATE MONDAY
NIGHT INTO TUESDAY. GIVEN PERSISTENT AND HIGHLY AMPLIFIED RIDGE
POSITIONED ACROSS THE MIDWEST...THINK A SLOWER BREAK DOWN TO THE
PATTERN IS PRUDENT. HAVE THEREFORE TRENDED THE FORECAST TOWARD THE
SLOWER ECMWF/GEM CONSENSUS. AS A RESULT...AM EXPECTING DRY
CONDITIONS THROUGH SUNDAY NIGHT...WITH HIGHER RAIN CHANCES ARRIVING
BY LATE MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 653 AM CDT MON AUG 31 2015
ASIDE FROM SOME EARLY MORNING IFR/MVFR FOG TODAY AND AGAIN LATE
TONIGHT, PREDOMINANTLY VFR CONDITIONS EXPECTED ACROSS THE CENTRAL
ILLINOIS TERMINALS THROUGH THE 12Z TAF VALID TIME. DIURNALLY
DRIVEN CU WILL POP THIS MORNING, WITH ISOLATED SHOWER/STORMS
POSSIBLY DEVELOPING. HOWEVER, SHOWER/STORM COVERAGE IS EXPECTED TO
BE TOO LOW TO MENTION AT THIS TIME. WINDS SHOULD CONTINUE TO BE
LIGHT OVERALL.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS LINCOLN IL
317 AM CDT MON AUG 31 2015
.SHORT TERM...(TODAY)
ISSUED AT 317 AM CDT MON AUG 31 2015
08Z/3AM SURFACE ANALYSIS SHOWS DISSIPATING FRONTAL BOUNDARY
EXTENDING FROM NORTHERN INDIANA INTO CENTRAL ILLINOIS...GENERALLY
ALONG A FORT WAYNE TO QUINCY LINE. AS WAS THE CASE LAST
NIGHT...QUITE A BIT OF FOG IS DEVELOPING ALONG/NORTH OF THE BOUNDARY
WHERE WINDS ARE NEARLY CALM AND LOW-LEVEL MOISTURE IS ABUNDANT.
LATEST OBS SHOW LOWEST VISBYS CONCENTRATED ALONG THE SOUTHERN SHORE
OF LAKE MICHIGAN ACROSS NORTHERN INDIANA INTO THE CHICAGO AREA.
HRRR HAS BEEN CONSISTENTLY SPREADING THIS THICKER FOG W/SW ALONG THE
FRONT INTO THE NORTHERN KILX CWA OVER THE NEXT COUPLE HOURS...AND AM
BEGINNING TO SEE THIS UNFOLDING WITH VISBY NOW DOWN TO 1/4SM AS FAR
SW AS KIKK. FOLLOWING THE HRRR TREND...WILL MENTION AREAS OF DENSE
FOG ALONG/NORTHEAST OF A GALESBURG TO BLOOMINGTON-NORMAL LINE EARLY
THIS MORNING...WITH PATCHY/AREAS OF FOG ELSEWHERE AROUND THE AREA.
HIGH-RES MODELS SUCH AS THE HRRR AND RAPID REFRESH ARE SUGGESTING
THAT ISOLATED CONVECTION MAY DEVELOP ACROSS SOUTHEAST ILLINOIS OVER
THE NEXT COUPLE OF HOURS. LATEST RADAR IMAGERY IS CLEAR...HOWEVER
SCATTERED MID-LEVEL CLOUDS ARE BEGINNING TO DEVELOP ON IR SATELLITE
IMAGERY ALONG/SOUTH OF I-70...SO HAVE OPTED TO CARRY SLIGHT CHANCE
POPS HERE EARLY THIS MORNING. LATEST WATER VAPOR IMAGERY SHOWS A
SMALL BUT VIGOROUS SHORT-WAVE DROPPING SOUTHWESTWARD FROM NORTHEAST
INDIANA. THIS FEATURE WILL LIKELY INTERACT WITH THE DECAYING FRONT
TO TRIGGER ISOLATED CONVECTION FURTHER NORTH INTO THE CWA THIS
AFTERNOON. MOST MODELS ARE HINTING AT LEAST SOME QPF ACROSS THE
SOUTHERN TWO-THIRDS OF THE AREA...SO HAVE ADDED SLIGHT CHANCE POPS
ALONG/SOUTH OF A JACKSONVILLE TO BLOOMINGTON-NORMAL LINE FOR THE
AFTERNOON.
&&
.LONG TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 317 AM CDT MON AUG 31 2015
MAIN WEATHER STORY THROUGH THE EXTENDED WILL BE THE VERY WARM AND
HUMID CONDITIONS THAT ARE EXPECTED TO PERSIST THROUGH EARLY NEXT
WEEK. HIGH TEMPERATURES ON TUESDAY WILL REACH THE UPPER 80S TO
AROUND 90 DEGREES...THEN READINGS WILL CLIMB INTO THE LOWER 90S FOR
THE REMAINDER OF THE PERIOD. DRY WEATHER WILL GENERALLY BE THE
RULE...HOWEVER ISOLATED CONVECTION CANNOT BE RULED OUT...ESPECIALLY
TUESDAY AFTERNOON AS A WEAKNESS IN THE MEAN 500MB RIDGE AXIS REMAINS
IN THE VICINITY. MODELS ARE HINTING AT SOME QPF ACROSS THE E/NE CWA
AS THIS FEATURE GRADUALLY SHIFTS INTO THE GREAT LAKES BY WEDNESDAY.
THE NEXT SIGNIFICANT CHANCE FOR RAIN WILL NOT ARRIVE UNTIL EARLY
NEXT WEEK...WHEN A STRONG SHORT-WAVE FLATTENS THE UPPER RIDGE AND
PUSHES A COLD FRONT INTO THE REGION. MODELS ARE IN DISAGREEMENT
CONCERNING THE SPEED OF THIS PROCESS...WITH THE GFS BEING ABOUT 24
HOURS FASTER THAN THE ECMWF/GEM. THE 00Z AUG 31 GFS SHOWS THE COLD
FRONT PASSING THROUGH CENTRAL ILLINOIS LATE SUNDAY NIGHT INTO
MONDAY...WHILE THE ECMWF/GEM HAVE DELAYED FROPA UNTIL LATE MONDAY
NIGHT INTO TUESDAY. GIVEN PERSISTENT AND HIGHLY AMPLIFIED RIDGE
POSITIONED ACROSS THE MIDWEST...THINK A SLOWER BREAK DOWN TO THE
PATTERN IS PRUDENT. HAVE THEREFORE TRENDED THE FORECAST TOWARD THE
SLOWER ECMWF/GEM CONSENSUS. AS A RESULT...AM EXPECTING DRY
CONDITIONS THROUGH SUNDAY NIGHT...WITH HIGHER RAIN CHANCES ARRIVING
BY LATE MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1153 PM CDT SUN AUG 30 2015
FOG AND LOW CLOUD FORMATION LATER TONIGHT REMAIN THE PRIMARY
CONCERNS. THE STALLED OUT FRONTAL BOUNDARY ACROSS CENTRAL IL IS
BEGINNING TO WASH OUT, BUT RESIDUAL MOISTURE IN THE BOUNDARY LAYER
HAS ALLOWED DEWPOINTS TO LINGER IN THE UPPER 60S TO LOW 70S
THROUGH THE EVENING. THE POTENTIAL FOR MVFR FOG IS HIGH IN A
MAJORITY OF THE AREA OVERNIGHT. HRRR/RAP OUTPUT ARE POINTING
TOWARD THE POTENTIAL OF LOCALIZED VLIFR FOG NEAR PIA AND BMI, AND
TO SOME EXTENT SPI AND DEC. THE NAM FORECAST SOUNDINGS SHOW AT
LEAST AN MVFR CLOUD LAYER WILL DEVELOP LATER TONIGHT AT MOST TAF
LOCATIONS. HAVE INCLUDED LIFR FOG AT PIA AND BMI WITH VLIFR CIGS
AT BMI. WILL CONTINUE WITH ONLY IFR FOG LATER TONIGHT FOR SPI, DEC
AND CMI, FOR NOW.
FOG SHOULD DISSIPATE BY MID MORNING, WITH MVFR CLOUDS POSSIBLY
LINGERING TO AROUND 17-18Z. VFR CONDITIONS SHOULD DEVELOP AT ALL
TAF SITES FOR THE AFTERNOON AND THROUGH THE EVENING.
WINDS WILL REMAIN LIGHT AND VARIABLE THE REST OF THE NIGHT, WITH
A PREVAILING S-SW WIND DEVELOPING AFTER SUNRISE TOMORROW. WIND
SPEEDS DURING PEAK MIXING TOMORROW SHOULD REMAIN 10KT OR LESS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
741 PM EDT TUE SEP 1 2015
.SYNOPSIS...
ISSUED AT 345 PM EDT TUE SEP 1 2015
SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE THROUGH THE
EVENING AND OVERNIGHT AS AN UPPER LEVEL DISTURBANCE MOVES THROUGH
THE AREA. ISOLATED AFTERNOON SHOWERS AND THUNDERSTORMS WILL THEN
BE POSSIBLE THROUGH THE END OF THE WEEK WITH HOT AND HUMID
CONDITIONS IN PLACE. HIGHS WILL BE MID TO UPPER 80S WITH LOWS IN
THE MID TO UPPER 60S.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 345 PM EDT TUE SEP 1 2015
PESKY COMPACT MIDLEVEL VORT MAX CONTINUES TO SWIRL ACROSS CENTRAL
INDIANA THIS AFTERNOON WITH LITTLE FORWARD MOMENTUM. DEWPOINTS IN
THE LOW 70S SUPPORTING SOME DECENT SBCAPE PER SPC/RAP MESOANALYSIS
DESPITE VERY POOR LAPSE RATES ALOFT. DPVA IN THE PRESENCE OF THIS
INSTABILITY IS GENERATING SOME SCT CONVECTION...WITH THE HIGHEST
COVERAGE IN OUR SOUTH CLOSER TO THE HEIGHT ANOMALY AND ALONG REMNANT
OUTFLOW FROM MORNING CONVECTION. EXPECT THIS ACTIVITY TO CONTINUE
THROUGH THE EVENING BUT SHOULD WANE WITH THE LOSS OF DAYTIME
HEATING.
MAIN LINE OF CONVECTION TO OUR W/SW THIS MORNING WAS ACTUALLY BEING
DRIVEN BY FOCUSED 305K ISENTROPIC UPGLIDE ON THE BACKSIDE OF
MIDLEVEL CIRCULATION. SOME OF THE LATEST MODELS (BOTH HI-RES AND
OTHERWISE) SHOW THIS AREA OF ENHANCED ASCENT AND MOISTURE
CONVERGENCE WITH 20-25 KT LLJ SETTING UP AGAIN OVER AT LEAST OUR
SOUTHEAST COUNTIES LATER TONIGHT...PROMPTING CONTINUED LOW CHANCE
POPS IN OUR EAST THROUGH TOMORROW. COVERAGE HIGHLY QUESTIONABLE
GIVEN WEAK FORCING AND INSTABILITY SO WILL MAINTAIN JUST SLIGHT
CHANCE POPS FOR NOW. NO SEVERE WEATHER EXPECTED WITH ANY OF THIS
ACTIVITY GIVEN LIMITED UPDRAFT POTENTIAL AND VIRTUALLY NO FLOW
ALOFT. COROLLARY TO THIS IS THAT ANY CONVECTION THAT DOES MANAGE TO
DEVELOP AND PERSIST WILL MOVE VERY SLOW AND COULD LEAD TO LOCALLY
HEAVY RAINFALL.
OTHER MAIN STORY WILL BE THE HEAT AND HUMIDITY. HIGHS TOMORROW
EXPECTED TO BE A FEW DEGREES WARMER THAN TODAY...APPROACHING 90F.
WITH DEWPOINTS IN THE LOW 70S ONCE AGAIN...HEAT INDICES WILL LIKELY
APPROACH THE MID 90S.
&&
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 345 PM EDT TUE SEP 1 2015
HOT AND HUMID CONDITIONS TO DOMINATE THE REGION THROUGH THE UPCOMING
HOLIDAY WEEKEND AND BEYOND WITH ONLY MINIMAL CHANCES FOR NEEDED
RAINFALL.
UPPER LEVEL RIDGING WILL CONTINUE TO INFLUENCE THE REGION INTO
FRIDAY WITH A SERIES OF WEAK DISTURBANCES RIDING ITS PERIPHERY. ONE
OF THESE IS POISED TO MOVE NE OUT OF PLAINS AND THEN DROP SE INTO
THE WESTERN GREAT LAKES THURSDAY AND LINGERING INTO FRIDAY. NAM/GFS
SOUNDINGS SUGGEST WE SHOULD BE UNCAPPED WITH AT LEAST LOW TO
MODERATE INSTABILITY AROUND. WILD CARD WILL BE AMOUNT OF SURFACE
CONVERGENCE ASSOCIATED WITH THIS FEATURE AND ITS ABILITY TO SPARK
ISOL TO MAYBE SCT CONVECTION. WILL BE KEEPING POPS SUBDUED FOR THE
TIME BEING IN THE SLGT CHC TO LOW CHC CATEGORY DURING THE
AFTERNOON/EVENING HOURS.
BY SATURDAY...MED RANGE MODELS ALL AGREE ON 588 DM OR HIGHER UPPER
LEVEL HEIGHTS NUDGING INTO THE REGION AND HOLDING TIGHT INTO MONDAY.
THIS WILL RESULT IN HIGHS WELL INTO THE 80S AND POSSIBLY AROUND 90
WITH HEAT INDICIES INTO THE 90S. DEEP LOW PRESSURE WILL MOVE INTO
THE WESTERN STATES SATURDAY AND MAKE AN ATTEMPT TO BREAK DOWN THE
RIDGE FOR THE START OF NEXT WEEK. ECMWF DOES SUGGEST A WEAK
DISTURBANCE WELL SOUTH OF THE MAIN UPPER LOW THAT COULD BRING AN
OUTSIDE CHANCE OF A AFTERNOON/EVENING SHOWER OR STORM TO THE AREA
TUESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 735 PM EDT TUE SEP 1 2015
ISOLATED THUNDERSTORMS HAVE AVOIDED BOTH TERMINALS THIS EVENING
AND THAT TREND APPEARS TO CONTINUE OVERNIGHT. DEWPOINTS IN THE LOW
70S LENDS SOME CONCERN FOR FOG POTENTIAL OVERNIGHT...BUT IT
APPEARS SW WINDS WILL BE JUST STRONG ENOUGH TO KEEP FOG
DEVELOPMENT AT BAY. THIS IS SUPPORTED BY LATEST RAP AND HRRR WHICH
KEEP VISIBILITIES P6SM ALL NIGHT. DECIDED TO KEEP TEMPO 4SM BR
MENTION IN THE TAF GIVEN THE AFOREMENTIONED MOIST LOW LEVEL
DEWPOINTS. OTHERWISE...A FEW SHOWERS AND THUNDERSTORMS ARE
POSSIBLE LATER TONIGHT ACROSS CENTRAL INDIANA AS THE LOW LEVEL JET
STRENGTHENS...BUT THESE SHOULD STAY SOUTH OF KFWA. SHOWERS AND
THUNDERSTORMS ON WEDNESDAY WILL LIKELY BE EVEN MORE WIDESPREAD
THAN TODAY...SO HAVE NOT INCLUDED ANY MENTION IN THIS TAF
ISSUANCE.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...FISHER
AVIATION...BENTLEY
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
1243 PM CDT MON AUG 31 2015
.UPDATE...
ISSUED AT 1243 PM CDT MON AUG 31 2015
MINOR UPDATE...KEEP SLIGHTLY MORE CLOUD COVER OVER THE WEST THOUGH
AREA SHOULD MIX OUT TO SCT BY MID TO LATE AFTERNOON. ALSO RAISED
TMAX ABOUT 2 DEGREES OVER THE WEST/CENTRAL/SOUTHEAST AS
TEMPERATURES CONTINUE TO CLIMB NOW THAT THE LOWER CLOUDS HAVE
DEPARTED./REV
UPDATE ISSUED AT 646 AM CDT MON AUG 31 2015
VISIBILITIES NEVER DETERIORATED AS EXPECTED OVER MUCH OF SOUTHERN
AND EAST CENTRAL IOWA...ONLY DOWN TO A FEW MILES AT WORST...SO THE
PREVIOUS ADVISORY HAS BEEN CANCELLED. LOW VISIBILITIES DO CONTINUE
IN AREAS OVER THE NORTHERN HALF OF IOWA HOWEVER...BUT THEY ARE
EXPECTED TO IMPROVE SHORTLY.
&&
.SHORT TERM /TODAY/...
ISSUED AT 320 AM CDT MON AUG 31 2015
MUCH LIKE YESTERDAY...THE MAIN CONCERNS ARE TEMP AND VISIBILITY
TRENDS. STRATUS COVERAGE IS LESS THAN LAST NIGHT WITH ONLY SOME
TOKEN CIRRUS NW. THIS WOULD SUGGEST A MORE UNIFORM RADIATION FOG
DEVELOPMENT BUT THAT HAS NOT BEEN THE CASE WITH VISIBILITIES
SOMEWHAT VARIABLE. EVEN THOUGH SRN IA WAS HIT HARDEST WITH DENSE FOG
LAST NIGHT AND CONDITIONS ARE SIMILAR...VISIBILITIES HAVE NOT REALLY
DROPPED MUCH IN THE ADVISORY AREA. RAP 1000-950MB RH IS ACTUALLY
RELATIVELY LOWER IN THIS AREA SO ADVISORY CONFIDENCE IS NOT GREAT.
HOWEVER CONFIDENCE IS EQUALLY NOT GREAT THAT CONDITIONS WILL NOT
TANK IN THE NEXT SEVERAL HOURS EITHER SO WILL LEAVE HEADLINE AS IS
AND EVALUATE HOURLY FOR NEEDED CHANGES. LOWEST VISIBILITIES ARE
ACTUALLY NORTH SO WILL GO WITH KEEPING HEADLINE AND SPS OTHER AREAS
FOR NOW.
TEMPS WILL BE PROBLEMATIC ONCE AGAIN. MODEL SOUNDINGS ARE SOMEWHAT
MORE AGGRESSIVE WITH MIXING POTENTIAL...WHICH MAKES SOME SENSE WITH
WINDS A TAD HIGHER AND LESS STRATUS AROUND. HOWEVER IS HAS BEEN
DIFFICULT WARMING TOO MUCH OVER THE PAST FEW WEEKS...ESPECIALLY TO
GFS EXPECTATIONS WHICH HAS SHOWN AND WARM BIAS. COOLER NAM MOS HAS
BEEN BETTER RECENTLY AND WILL CONTINUE TO FOLLOW THAT LEAD. THIS
RESULTS IN TRIMMING PREVIOUS FORECAST SEVERAL DEGREES.
.LONG TERM /TONIGHT THROUGH SUNDAY/...
ISSUED AT 320 AM CDT MON AUG 31 2015
THE FORECAST FOR THIS WEEK REMAINS WARM AND MOSTLY DRY. A DEEP
LAYER RIDGE BLANKETING THE SOUTHERN U.S. WILL GRADUALLY PIVOT
AROUND OVER THE EASTERN U.S. AS A LONGWAVE TROUGH STEADILY DIGS
DOWN THE WEST COAST. THIS WILL PLACE IOWA BENEATH THE PROVERBIAL
RING OF FIRE FOR SEVERAL DAYS THIS WEEK...HOWEVER...THE SUBTLE
SHORTWAVES MOVING THROUGH THE STEERING FLOW ALOFT WILL BE FAIRLY
WEAK AND DIFFICULT TO PIN DOWN IN TERMS OF TIMING. WILL MAINTAIN
LOW 20 TO 30 POPS AT TIMES DURING THE WORK WEEK...MAINLY ACROSS
THE NORTHWEST HALF OF THE FORECAST AREA...BUT ANY STORMS SHOULD BE
OF LITTLE IMPACT. MEANWHILE TEMPERATURES WILL CLIMB WELL INTO THE
80S EACH DAY GIVEN THE WARM TEMPERATURES ALOFT...MODEST SOUTH TO
SOUTHWEST LOW LEVEL FLOW...AND MOSTLY SUNNY SKIES FORECAST.
LATER IN THE WEEK...FROM ABOUT THURSDAY THROUGH SATURDAY...THE
DEEPENING WESTERN TROUGH WILL SHUNT THE LARGE SOUTHERN RIDGE OVER
TOWARD THE APPALACHIANS AND RESULT IN ANY SUBTLE SHORTWAVES
EJECTING OUT OF THE TROUGH MOVING MORE NORTHEASTWARD ACROSS THE
HIGH PLAINS AND MINNESOTA. THIS RESULTS IN A PERIOD OF LOWER POPS
BUT SLIGHTLY HIGHER TEMPERATURES AS ANY STORMS THAT FORM SHOULD
RANGE FROM NEBRASKA UP ACROSS THE DAKOTAS AND THE WARM AIRMASS TO
OUR SOUTHEAST WILL ENCROACH A BIT MORE INTO IOWA BY THE END OF THE
WEEK. THE WEST COAST TROUGH WILL EVENTUALLY KICK OUT ACROSS THE
CENTRAL U.S. AND PUSH A COLD FRONT ACROSS OUR REGION...GENERATING
MORE WIDESPREAD SHOWERS AND THUNDERSTORMS FOLLOWED BY COOLER
WEATHER. HOWEVER...THERE CONTINUES TO BE A CONSIDERABLE AMOUNT OF
SPREAD AMONG THE LONG RANGE MODELS IN THEIR SOLUTIONS FOR THIS
EVOLUTION AND PARTICULARLY THE TIMING OF RAIN AND FRONTAL PASSAGE
FOR IOWA. HAVE THUS STUCK CLOSE TO MODEL CONSENSUS WITH RAIN
CHANCES MOSTLY IN THE SUNDAY/SUNDAY NIGHT TIME FRAMES AND COOLER
WEATHER LIKELY BY NEXT MONDAY. THESE DETAILS WILL GRADUALLY COME
INTO FOCUS LATER THIS WEEK.
&&
.AVIATION...31/18Z
ISSUED AT 1243 PM CDT MON AUG 31 2015
SIMILAR CONCERNS OF PAST FEW NIGHTS...ABUNDANT LOW LEVEL MOISTURE
WITH LIGHT WINDS OVERNIGHT. AS UPPER LEVEL TROUGH AND SFC
REFLECTION BOTH REMAIN NORTHWEST OF THE AREA TONIGHT/TUE
MORNING...WILL EXPECT TO SEE BR/POSSIBLE FG AGAIN DEVELOP AFT 06Z.
HAVE NOT HIT TERMINALS AS HARD WITH VSBY AS AIRMASS CONTINUES TO
WARM WHICH SHOULD OFFSET POTENTIAL FOR WIDESPREAD THICK FOG. NONE
THE LESS...HAVE LOWERED A FEW SPOTS TO 1SM...2SM BY 09-12Z. LIKELY
THE LAYER WILL BE SHALLOWER THAN PAST NIGHTS THOUGH SOME
UNCERTAINTY WITH THAT. 00Z/06Z PACKAGES SHOULD HAVE A BETTER IDEA
OF DETAILS. OTHERWISE...WIND OF LITTLE CONCERN THOUGH SOME MIXING
EXPECTED WEST TODAY/TOMORROW.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...REV
SHORT TERM...SMALL
LONG TERM...LEE
AVIATION...REV
AREA FORECAST DISCUSSION
NWS DES MOINES IA
647 AM CDT MON AUG 31 2015
.UPDATE...
ISSUED AT 646 AM CDT MON AUG 31 2015
VISIBILITIES NEVER DETERIORATED AS EXPECTED OVER MUCH OF SOUTHERN
AND EAST CENTRAL IOWA...ONLY DOWN TO A FEW MILES AT WORST...SO THE
PREVIOUS ADVISORY HAS BEEN CANCELLED. LOW VISIBILITIES DO CONTINUE
IN AREAS OVER THE NORTHERN HALF OF IOWA HOWEVER...BUT THEY ARE
EXPECTED TO IMPROVE SHORTLY.
&&
.SHORT TERM /TODAY/...
ISSUED AT 320 AM CDT MON AUG 31 2015
MUCH LIKE YESTERDAY...THE MAIN CONCERNS ARE TEMP AND VISIBILITY
TRENDS. STRATUS COVERAGE IS LESS THAN LAST NIGHT WITH ONLY SOME
TOKEN CIRRUS NW. THIS WOULD SUGGEST A MORE UNIFORM RADIATION FOG
DEVELOPMENT BUT THAT HAS NOT BEEN THE CASE WITH VISIBILITIES
SOMEWHAT VARIABLE. EVEN THOUGH SRN IA WAS HIT HARDEST WITH DENSE FOG
LAST NIGHT AND CONDITIONS ARE SIMILAR...VISIBILITIES HAVE NOT REALLY
DROPPED MUCH IN THE ADVISORY AREA. RAP 1000-950MB RH IS ACTUALLY
RELATIVELY LOWER IN THIS AREA SO ADVISORY CONFIDENCE IS NOT GREAT.
HOWEVER CONFIDENCE IS EQUALLY NOT GREAT THAT CONDITIONS WILL NOT
TANK IN THE NEXT SEVERAL HOURS EITHER SO WILL LEAVE HEADLINE AS IS
AND EVALUATE HOURLY FOR NEEDED CHANGES. LOWEST VISIBILITIES ARE
ACTUALLY NORTH SO WILL GO WITH KEEPING HEADLINE AND SPS OTHER AREAS
FOR NOW.
TEMPS WILL BE PROBLEMATIC ONCE AGAIN. MODEL SOUNDINGS ARE SOMEWHAT
MORE AGGRESSIVE WITH MIXING POTENTIAL...WHICH MAKES SOME SENSE WITH
WINDS A TAD HIGHER AND LESS STRATUS AROUND. HOWEVER IS HAS BEEN
DIFFICULT WARMING TOO MUCH OVER THE PAST FEW WEEKS...ESPECIALLY TO
GFS EXPECTATIONS WHICH HAS SHOWN AND WARM BIAS. COOLER NAM MOS HAS
BEEN BETTER RECENTLY AND WILL CONTINUE TO FOLLOW THAT LEAD. THIS
RESULTS IN TRIMMING PREVIOUS FORECAST SEVERAL DEGREES.
.LONG TERM /TONIGHT THROUGH SUNDAY/...
ISSUED AT 320 AM CDT MON AUG 31 2015
THE FORECAST FOR THIS WEEK REMAINS WARM AND MOSTLY DRY. A DEEP
LAYER RIDGE BLANKETING THE SOUTHERN U.S. WILL GRADUALLY PIVOT
AROUND OVER THE EASTERN U.S. AS A LONGWAVE TROUGH STEADILY DIGS
DOWN THE WEST COAST. THIS WILL PLACE IOWA BENEATH THE PROVERBIAL
RING OF FIRE FOR SEVERAL DAYS THIS WEEK...HOWEVER...THE SUBTLE
SHORTWAVES MOVING THROUGH THE STEERING FLOW ALOFT WILL BE FAIRLY
WEAK AND DIFFICULT TO PIN DOWN IN TERMS OF TIMING. WILL MAINTAIN
LOW 20 TO 30 POPS AT TIMES DURING THE WORK WEEK...MAINLY ACROSS
THE NORTHWEST HALF OF THE FORECAST AREA...BUT ANY STORMS SHOULD BE
OF LITTLE IMPACT. MEANWHILE TEMPERATURES WILL CLIMB WELL INTO THE
80S EACH DAY GIVEN THE WARM TEMPERATURES ALOFT...MODEST SOUTH TO
SOUTHWEST LOW LEVEL FLOW...AND MOSTLY SUNNY SKIES FORECAST.
LATER IN THE WEEK...FROM ABOUT THURSDAY THROUGH SATURDAY...THE
DEEPENING WESTERN TROUGH WILL SHUNT THE LARGE SOUTHERN RIDGE OVER
TOWARD THE APPALACHIANS AND RESULT IN ANY SUBTLE SHORTWAVES
EJECTING OUT OF THE TROUGH MOVING MORE NORTHEASTWARD ACROSS THE
HIGH PLAINS AND MINNESOTA. THIS RESULTS IN A PERIOD OF LOWER POPS
BUT SLIGHTLY HIGHER TEMPERATURES AS ANY STORMS THAT FORM SHOULD
RANGE FROM NEBRASKA UP ACROSS THE DAKOTAS AND THE WARM AIRMASS TO
OUR SOUTHEAST WILL ENCROACH A BIT MORE INTO IOWA BY THE END OF THE
WEEK. THE WEST COAST TROUGH WILL EVENTUALLY KICK OUT ACROSS THE
CENTRAL U.S. AND PUSH A COLD FRONT ACROSS OUR REGION...GENERATING
MORE WIDESPREAD SHOWERS AND THUNDERSTORMS FOLLOWED BY COOLER
WEATHER. HOWEVER...THERE CONTINUES TO BE A CONSIDERABLE AMOUNT OF
SPREAD AMONG THE LONG RANGE MODELS IN THEIR SOLUTIONS FOR THIS
EVOLUTION AND PARTICULARLY THE TIMING OF RAIN AND FRONTAL PASSAGE
FOR IOWA. HAVE THUS STUCK CLOSE TO MODEL CONSENSUS WITH RAIN
CHANCES MOSTLY IN THE SUNDAY/SUNDAY NIGHT TIME FRAMES AND COOLER
WEATHER LIKELY BY NEXT MONDAY. THESE DETAILS WILL GRADUALLY COME
INTO FOCUS LATER THIS WEEK.
&&
.AVIATION...31/12Z
ISSUED AT 646 AM CDT MON AUG 31 2015
FOG TRENDS REMAIN THE PRIMARY CONCERN EARLY THIS MORNING.
CONDITIONS VARY WIDELY AT TAF SITES FROM LIFR /KMCW/ TO VFR /KDSM/
BUT ALL SITES SHOULD CONTINUE TO IMPROVE THROUGH 15Z. ALTHOUGH
SOME SCT/BKN CU MAY DEVELOP DURING PEAK HEATING OF THE DAY...THEY
SHOULD BE ABOVE 3K FT WITH VFR ANTICIPATED THROUGH THE AFTERNOON
AND EVENING. SOME PATCHY MVFR RADIATION FOG MAY DEVELOP AGAIN INTO
EARLY TUE MORNING...BUT NOT TO THE EXTENT SEEN THE PAST FEW
MORNINGS.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...SMALL
SHORT TERM...SMALL
LONG TERM...LEE
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
320 AM CDT MON AUG 31 2015
.SHORT TERM /TODAY/...
ISSUED AT 320 AM CDT MON AUG 31 2015
MUCH LIKE YESTERDAY...THE MAIN CONCERNS ARE TEMP AND VISIBILITY
TRENDS. STRATUS COVERAGE IS LESS THAN LAST NIGHT WITH ONLY SOME
TOKEN CIRRUS NW. THIS WOULD SUGGEST A MORE UNIFORM RADIATION FOG
DEVELOPMENT BUT THAT HAS NOT BEEN THE CASE WITH VISIBILITIES
SOMEWHAT VARIABLE. EVEN THOUGH SRN IA WAS HIT HARDEST WITH DENSE FOG
LAST NIGHT AND CONDITIONS ARE SIMILAR...VISIBILITIES HAVE NOT REALLY
DROPPED MUCH IN THE ADVISORY AREA. RAP 1000-950MB RH IS ACTUALLY
RELATIVELY LOWER IN THIS AREA SO ADVISORY CONFIDENCE IS NOT GREAT.
HOWEVER CONFIDENCE IS EQUALLY NOT GREAT THAT CONDITIONS WILL NOT
TANK IN THE NEXT SEVERAL HOURS EITHER SO WILL LEAVE HEADLINE AS IS
AND EVALUATE HOURLY FOR NEEDED CHANGES. LOWEST VISIBILITIES ARE
ACTUALLY NORTH SO WILL GO WITH KEEPING HEADLINE AND SPS OTHER AREAS
FOR NOW.
TEMPS WILL BE PROBLEMATIC ONCE AGAIN. MODEL SOUNDINGS ARE SOMEWHAT
MORE AGGRESSIVE WITH MIXING POTENTIAL...WHICH MAKES SOME SENSE WITH
WINDS A TAD HIGHER AND LESS STRATUS AROUND. HOWEVER IS HAS BEEN
DIFFICULT WARMING TOO MUCH OVER THE PAST FEW WEEKS...ESPECIALLY TO
GFS EXPECTATIONS WHICH HAS SHOWN AND WARM BIAS. COOLER NAM MOS HAS
BEEN BETTER RECENTLY AND WILL CONTINUE TO FOLLOW THAT LEAD. THIS
RESULTS IN TRIMMING PREVIOUS FORECAST SEVERAL DEGREES.
.LONG TERM /TONIGHT THROUGH SUNDAY/...
ISSUED AT 320 AM CDT MON AUG 31 2015
THE FORECAST FOR THIS WEEK REMAINS WARM AND MOSTLY DRY. A DEEP
LAYER RIDGE BLANKETING THE SOUTHERN U.S. WILL GRADUALLY PIVOT
AROUND OVER THE EASTERN U.S. AS A LONGWAVE TROUGH STEADILY DIGS
DOWN THE WEST COAST. THIS WILL PLACE IOWA BENEATH THE PROVERBIAL
RING OF FIRE FOR SEVERAL DAYS THIS WEEK...HOWEVER...THE SUBTLE
SHORTWAVES MOVING THROUGH THE STEERING FLOW ALOFT WILL BE FAIRLY
WEAK AND DIFFICULT TO PIN DOWN IN TERMS OF TIMING. WILL MAINTAIN
LOW 20 TO 30 POPS AT TIMES DURING THE WORK WEEK...MAINLY ACROSS
THE NORTHWEST HALF OF THE FORECAST AREA...BUT ANY STORMS SHOULD BE
OF LITTLE IMPACT. MEANWHILE TEMPERATURES WILL CLIMB WELL INTO THE
80S EACH DAY GIVEN THE WARM TEMPERATURES ALOFT...MODEST SOUTH TO
SOUTHWEST LOW LEVEL FLOW...AND MOSTLY SUNNY SKIES FORECAST.
LATER IN THE WEEK...FROM ABOUT THURSDAY THROUGH SATURDAY...THE
DEEPENING WESTERN TROUGH WILL SHUNT THE LARGE SOUTHERN RIDGE OVER
TOWARD THE APPALACHIANS AND RESULT IN ANY SUBTLE SHORTWAVES
EJECTING OUT OF THE TROUGH MOVING MORE NORTHEASTWARD ACROSS THE
HIGH PLAINS AND MINNESOTA. THIS RESULTS IN A PERIOD OF LOWER POPS
BUT SLIGHTLY HIGHER TEMPERATURES AS ANY STORMS THAT FORM SHOULD
RANGE FROM NEBRASKA UP ACROSS THE DAKOTAS AND THE WARM AIRMASS TO
OUR SOUTHEAST WILL ENCROACH A BIT MORE INTO IOWA BY THE END OF THE
WEEK. THE WEST COAST TROUGH WILL EVENTUALLY KICK OUT ACROSS THE
CENTRAL U.S. AND PUSH A COLD FRONT ACROSS OUR REGION...GENERATING
MORE WIDESPREAD SHOWERS AND THUNDERSTORMS FOLLOWED BY COOLER
WEATHER. HOWEVER...THERE CONTINUES TO BE A CONSIDERABLE AMOUNT OF
SPREAD AMONG THE LONG RANGE MODELS IN THEIR SOLUTIONS FOR THIS
EVOLUTION AND PARTICULARLY THE TIMING OF RAIN AND FRONTAL PASSAGE
FOR IOWA. HAVE THUS STUCK CLOSE TO MODEL CONSENSUS WITH RAIN
CHANCES MOSTLY IN THE SUNDAY/SUNDAY NIGHT TIME FRAMES AND COOLER
WEATHER LIKELY BY NEXT MONDAY. THESE DETAILS WILL GRADUALLY COME
INTO FOCUS LATER THIS WEEK.
&&
.AVIATION...31/06Z
ISSUED AT 1144 PM CDT SUN AUG 30 2015
MAIN CONCERN WILL BE FOG AND STRATUS POTENTIAL. EXPECT AT LEAST MVFR
CONDITIONS OVERNIGHT...WITH MANY LOCATIONS IFR OR LOWER. KFOD AND
KMCW WILL SEE THE LOWER VSBYS INITIALLY...WITH LOWER VSBYS MIGRATING
SOUTHEASTWARD TOWARD THE KOTM AND POSSIBLY KDSM TERMINALS. CLOUDS
MOVING IN FROM THE WEST MAY MITIGATE THE LOWER VSBYS ACROSS WESTERN
IA. DURING THE DAY ON MONDAY...VFR FLIGHT RULES EXPECTED.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 8 AM CDT THIS MORNING FOR APPANOOSE-
CLARKE-DAVIS-DECATUR-JASPER-LUCAS-MAHASKA-MARION-MONROE-
POWESHIEK-TAMA-WAPELLO-WARREN-WAYNE.
&&
$$
SHORT TERM...SMALL
LONG TERM...LEE
AVIATION...ZOGG
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1150 PM CDT SUN AUG 30 2015
.UPDATE...
ISSUED AT 720 PM CDT SUN AUG 30 2015
HAVE GONE OUT WITH A DENSE FOG ADVISORY FOR MOST OF EASTERN IA AND
ADJACENT IL COUNTIES ALONG I-80 FOR LATE TONIGHT THROUGH EARLY
MORNING MONDAY. CONDITIONS ARE SIMILAR TO LAST NIGHT...WITH THE
SAME AIRMASS IN PLACE AND NEARLY CALM WINDS UNDER THE W-E SURFACE
RIDGE OVERHEAD. SURFACE DEWPOINTS ARE HIGHER IN MANY PLACES THAN
LAST NIGHT AT THIS TIME. CROSSOVER TECHNIQUE...USING DEWPOINTS AT
PEAK HEATING AND CURRENT FORECAST LOWS SUPPORTS WIDESPREAD FOG.
THE FOG COULD BE A LITTLE LATER TO DEVELOP DUE TO THE HIGHER
TEMPERATURES AND TEMP/DEWPOINT DEPARTURES AT THIS TIME TONIGHT VS
THIS TIME LAST NIGHT.
&&
.SYNOPSIS...
ISSUED AT 333 PM CDT SUN AUG 30 2015
SURFACE RIDGE AXIS EXTENDS FROM THE GREAT LAKES THROUGH THE CWA
AND INTO THE SOUTH CENTRAL PLAINS AT MID AFTN. THE FAIRLY
WIDESPREAD DENSE FOG BURNED OFF BY MID TO LATE AM LEAVING BEHIND
FAIRLY EXTENSIVE STRATUS WHICH HAS BEEN STEADILY ERODING FROM THE
SOUTH AND EVOLVING INTO SCATTERED STRATOCU DECK. THE INCREASING
PEAKS OF SUNSHINE HAS HELPED TO BUMP TEMPS UP TO NEAR LATE
AUGUST NORMALS WITH MANY AREAS IN THE UPPER 70S TO LOWER 80S.
THE EXCEPTION BEING MAINLY PORTIONS OF NORTHEAST IA WHERE STRATUS
SILL LINGERS AND AIDING IN HOLDING TEMPS DOWN IN THE LOWER 70S
ATTIM... BUT WITH MORE LATE DAY SUNSHINE SHOULD SEE TEMPS IN THESE
AREAS SURGE LATE. PATTERN ALOFT FEATURES AN AMPLIFIED RIDGE /HEAT DOME/
THROUGH THE PLAINS IN ADVANCE OF A PACIFIC NORTHWEST TROUGH. THE NEXT
24 HOURS WILL SEE THIS RIDGE AND WARMER AIR BUILD INTO THE MID-
MISSISSIPPI VLY AS THE PACIFIC NORTHWEST TROUGH SHIFTS ACROSS THE
NORTHERN ROCKIES. THIS WILL RESULT IN CONTINUATION OF DRY CONDITIONS
WITH WARMER TEMPS ON MONDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 333 PM CDT SUN AUG 30 2015
MAIN CHALLENGE REMAINS LOW CLOUDS AND FOG POTENTIAL WITH IMPACT ON
TEMPS.
FOLLOWING TRENDS PER SATL AND OBS FROM LATE AFTN WITH DECREASING STRATUS
NORTHWEST CWA EVOLVING INTO SCATTERED STRATOCUMULUS THEN MOSTLY
CLEAR FOR A TIME THIS EVENING. LATE EVENING AND OVERNIGHT WITH
CONTINUED WEAK WINDS AND ABUNDANT LOW LEVEL MOISTURE EXPECT
REDEVELOPMENT OF FOG DENSE IN SOME AREAS... WITH ALSO SOME STRATUS
POSSIBLE ALTHOUGH UNCERTAIN ON EXTENT OF ANY STRATUS FORMATION WITH
LATEST RAP AND NAM MODELS SHOWING AROUND 15+ KTS OF WIND JUST ABOVE
MOIST LAYER WHICH MAY BE SUFFICIENT MIXING TO OFFSET WIDESPREAD STRATUS
FORMATION AND WITH JUST DIURNAL CUMULUS ACROSS MO DON/T EXPECT ANY
ADVECTION OF LOW DECK. MIN TEMPS WILL BE CHALLENGING AND DEPENDENT ON
FOG AND STRATUS TRENDS. AS WE SAW THIS AM... POTENTIAL FOR AREAS THAT
STAY CLEAR LONGER TO RADIATE DOWN INTO THE 50S WITH NEAR CALM WINDS.
OTHERWISE... WITH TEMPS A BIT WARMER TODAY FOR MANY AND WITH MID AFTN
DEWPTS IN MID/UPPER 60S I HAVE KEPT LOWS MAINLY IN RANGE OF 60-67 DEGS.
ON MONDAY...ANY FOG SHOULD BURN OFF A BIT EARLIER TOMORROW BY MID AM
WITH A BIT STRONGER SOUTHERLY WIND DEVELOPING OF 5-10 KTS. ANY
STRATUS SHOULD LIFT TO FAIR WX CUMULUS DURING AFTERNOON AND GENERALLY
MOSTLY SUNNY SKIES. THIS WILL ALLOW TEMPS TO CLIMB WELL INTO THE 80S
WITH WIDESPREAD MID TO A FEW UPPER 80S. THESE TEMPS COUPLED WITH
DEWPTS WELL IN THE 60S TO NEAR 70 DEGS WILL MAKE FOR VERY WARM FEEL
WITH HEAT INDICES AROUND 90/L90S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 333 PM CDT SUN AUG 30 2015
OVERVIEW...BUILDING AND PERSISTENT UPPER-LEVEL RIDGE OVER THE
CENTRAL U.S. WILL LEAD TO ABOVE AVERAGE TEMPERATURES AND HUMID
CONDITIONS THROUGH THE EXTENDED PERIOD. OVERALL CHANCES FOR RAIN
ARE VERY LOW.
TUESDAY AND WEDNESDAY...1000-500MB THICKNESS VALUES ARE FORECAST TO
BE NEAR 576-579 DAM WITH 850MB TEMPS IN THE UPPER TEENS/NEAR 20 C.
FORECAST HIGHS ARE IN THE UPPER 80S TO NEAR 90 F...WITH HEAT INDICES
IN THE LOWER TO MIDDLE 90S.
A SHORTWAVE TROUGH FROM REMNANT MONSOONAL CONVECTION MAY TRAVERSE
THE MIDWEST ON WEDNESDAY BUT MODELS TRACK IT NW OF E IOWA/W
ILLINOIS. CONSEQUENTLY KEPT THE FORECAST DRY.
THURSDAY THROUGH SATURDAY...RAW MODELS STILL APPEAR TO HAVE A WARM
BIAS AND ARE PROJECTING LOWER TO MIDDLE 90S. HUMID
CONDITIONS...850MB TEMPS IN THE UPPER TEENS TO POSSIBLY LOWER 20S
CELSIUS...AND A LOWER SEPTEMBER SUN ANGLE BACK A TEMP FORECAST
SLIGHTLY BELOW THE HIGHER RAW MODEL DATA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1150 PM CDT SUN AUG 30 2015
PATCHY FOG WILL BECOME MORE WIDESPREAD AND DENSE DUE TO LIGHT
WINDS AND LINGERING LOW LEVEL MOISTURE IN A WEAK FLOW REGIME OVER
THE REGION. FORECASTS ARE TRENDED WITH A HIGH CONFIDENCE
TRANSITION TO IFR BY 08Z WITH A POTENTIAL FOR LIFR TO VLIFR DUE TO
BOTH REDUCED VISIBILITIES AND DEVELOPING LOW CIGS AND VERTICAL
VISIBILITIES FROM 08Z THROUGH ROUGHLY 13Z. AN IMPROVEMENT TREND
FOLLOWS THROUGH ROUGHLY 15Z...WITH HIGH CONFIDENCE THAT ALL SITES
SHOULD BE AT LEAST MVFR BY NOON AND THEN VFR BY AFTERNOON AS FOG
DISSIPATES AND CIGS LIFT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...DENSE FOG ADVISORY UNTIL 8 AM CDT MONDAY FOR BENTON-CEDAR-
CLINTON-DES MOINES-HENRY IA-IOWA-JACKSON-JEFFERSON-JOHNSON-
JONES-KEOKUK-LEE-LINN-LOUISA-MUSCATINE-SCOTT-VAN BUREN-
WASHINGTON.
IL...DENSE FOG ADVISORY UNTIL 8 AM CDT MONDAY FOR HENDERSON-HENRY IL-
MERCER-ROCK ISLAND-WHITESIDE.
MO...NONE.
&&
$$
UPDATE...SHEETS
SYNOPSIS...MCCLURE
SHORT TERM...MCCLURE
LONG TERM...UTTECH
AVIATION...SHEETS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
648 PM CDT TUE SEP 1 2015
...Update to aviation forecast discussion...
.SHORT TERM...(THIS EVENING THROUGH Wednesday)
ISSUED AT 339 PM CDT TUE SEP 1 2015
The upper levels show a broad upper ridge over the eastern CONUS
with a longwave trough just making its way into the Pacific
Northwest. Currently, most Radar sites across the Central Plains
remain quiet with only some rain showers over southeastern South
Dakota. Cloud tops have progressively cooled throughout the day
indicating that storms have been dissipating. This area of showers
appears to be in advance of a mid to upper level low amplitude
shortwave that is showing signs of weakening with decreasing
vorticity as it lifts further to the northeast from the lee trough
region of the Rockies.
Daytime mixing has allowed for some gusty winds at the surface today
as we are still under plenty of sunshine over northeastern KS. This
is expected to continue until tonight as winds calm as we begin to
lose insolation and the source of heating at the surface. Still
expecting that the previously mentioned shortwave will have at least
minor impacts tonight over north central and northeastern KS
tonight into the early morning hours Wednesday. Most short-term
high resolution guidance, such as the HRRR and RAP, suggest that
weak isentropic lift at around 310K level and a little extra
enhancement from the LLJ around 850mb will help create some small
areas of precip. With at least some midlevel instability due to
the remnants of the shortwave, there could be some elevated
thunderstorms. It is possible with drier low-levels per NAM and
RAP soundings that there could be some areas of stronger winds
with the more enhanced areas of thunderstorms and precip.
Expecting that tomorrow will be similar to today. As the clouds
from over night clear, expect mixing to occur once again with
highs climbing into the low 90s. Depending on how many clouds
remain, temps may need to be revised up a bit. As for lows
tonight, do expect temps to reach lower 70s which is up a bit due
to the expected cloud cover overnight.
.LONG TERM...(Wednesday NIGHT THROUGH Tuesday)
ISSUED AT 339 PM CDT TUE SEP 1 2015
Wednesday night through Friday afternoon...More of the same sensible
weather with highs in the 90s and lows in the 70s. Plume of
moisture continues to move into the four corners and southern and
Central Rockies as the western trof absorbs tropical energy from
near Baja. Weak wave may generate some isolated overnight showers
or a storm northwest late Wednesday night into early Thursday
morning, otherwise the ridge noses northward and keeps most of the
area dry and warm for the mid term period.
Friday night through Tuesday...Friday night and Saturday look to
be dry, before chances for precipitation start to increase Sunday
through Tuesday. An upper level system moving over the NW CONUS
Saturday will progress east along with an associated cold front.
With southerly winds advecting ample moisture into the region and
an advancing cold front, expect showers and storms to develop in
NE Kansas mainly early Monday morning through Tuesday. Models also
seem to be in better agreement with this timing. Cooler
temperatures are expected as that front passes, with lows in the
mid 60s Monday night and highs topping out in the low 80s on
Tuesday.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z Wednesday EVENING)
ISSUED AT 647 PM CDT TUE SEP 1 2015
For the 00z TAFs, VFR conditions are expected through the period.
There is the potential for some isolated to scattered showers and
thunderstorms to clip the TAF sites late overnight into Wednesday
morning, however confidence in the location of any of these isolated
showers is not high enough to warrant a mention in the TAFs at this
time, but will continue to monitor this potential. With the low-
level jet axis centered over central KS tonight, there is the
potential for some brief low-level wind shear concerns, especially
near KMHK as it is located closer to this increasing low-level jet.
Cannot rule out the potential for some borderline low-level wind
shear concerns near KTOP/KFOE so will continue to monitor this
potential as well. Otherwise, expect increasing southerly winds by
Wednesday afternoon.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Drake
LONG TERM...67/Heller
AVIATION...Hennecke
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
102 PM EDT MON AUG 31 2015
...UPDATED AVIATION DISCUSSION...
...FORECAST UPDATE...
ISSUED AT 1155 AM EDT MON AUG 31 2015
GOES SOUNDER DATA INDICATE PRECIPITABLE WATER LEVELS ARE AROUND 1.3
INCHES...QUITE A BIT LESS THAN THIS TIME YESTERDAY. AMDAR SOUNDINGS
SHOW A PRETTY GOOD CAP AT 500 MB. LATEST RUC SOUNDINGS SHOW MORE PW
THAN WHAT THE GOES SOUNDER HAS. WITH THE DRYING OUT...MULTIPLE
MODELS SHOW LITTLE IN THE WAY OF PRECIP. DECIDED TO BACK OFF ON POPS
FOR ALL BUT OUR NORTHERN STRIPE OF COUNTIES IN INDIANA. REST OF THE
FORECAST LOOKS GOOD WITH LOUISVILLE METRO GETTING TO THE UPPER 80S
AND THE REST OF THE AREA IN THE MID 80S.
.SHORT TERM (NOW THROUGH TUESDAY)...
ISSUED AT 315 AM EDT MON AUG 31 2015
EARLY THIS MORNING SOME PATCHY FOG HAS DEVELOPED IN SPOTS. THINK WE
MAY SEE MORE DEVELOP ESPECIALLY IN AREAS THAT RECEIVED RAINFALL
YESTERDAY, SO WILL CONTINUE EARLY MORNING PATCHY FOG MENTION BUT
DON`T THINK FOG SHOULD BECOME DENSE OR WIDESPREAD. FOG SHOULD
DIMINISH SHORTLY AFTER SUNRISE.
FOR THE REST OF THE DAY, EXPECT PARTLY CLOUDY SKIES WITH ISOLATED
AFTERNOON/EVENING SHOWERS/STORMS DEVELOPING AGAIN. RIDGING WILL BE
ON THE INCREASE TODAY AND INHIBIT CONVECTION COVERAGE A LITTLE MORE
THAN YESTERDAY. THE MOST LIKELY LOCATIONS TO SEE AN ISLD SHOWER OR
STORM LOOK TO BE SOUTHERN INDIANA OR NORTH CENTRAL KY WHERE CAPPING
MAY BE WEAKER. EXPECT HIGH TEMPS TO BE SIMILAR TO YESTERDAY IN THE
MIDDLE 80S.
TONIGHT IS EXPECTED TO BE MAINLY DRY WITH ANY CONVECTION ENDING
DURING THE EVENING HOURS. RIDGING WILL CONTINUE TO INCREASE OVER
THE REGION WITH A GOOD MID LEVEL CAP NOTED IN SOUNDINGS FOR TUESDAY.
THEREFORE WILL KEEP TUES DRY. LOWS TONIGHT SHOULD RANGE FROM THE
MID 60S TO AROUND 70. HIGHS ON TUES WILL WARM INTO THE UPPER 80S TO
AROUND 90.
.LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...
ISSUED AT 258 AM EDT MON AUG 31 2015
THE MAIN STORY FOR THE LONG TERM PERIOD IS THE LIKELY HOT AND DRY
CONDITIONS AS WE HEAD INTO THE FIRST FULL WEEK OF SEPTEMBER AND THE
UPCOMING HOLIDAY WEEKEND.
THE 31.00Z GUIDANCE TRENDED TOWARD SIMILAR SOLUTIONS WITH REGARD TO
THE UPPER LEVEL PATTERN...SHOWING BUILDING HEIGHTS AND RIDGING
WEDNESDAY THROUGH THIS UPCOMING WEEKEND. AT THE SURFACE...THE REGION
WILL BE MOSTLY UNDER THE INFLUENCE OF HIGH PRESSURE.
SENSIBLE WEATHER INCLUDES SEASONABLY WARM TO HOT CONDITIONS AS
READINGS TOP OUT IN THE UPPER 80S TO LOW 90S EACH AFTERNOON. LOOKING
AT SOME OF THE EXTENDED ENSEMBLE MOS DATA...THURSDAY THROUGH
SATURDAY LOOK TO BE THE WARMEST...AND A FEW MID 90 READINGS ARE
POSSIBLE IN THE TYPICAL WARM SPOTS AND URBAN CORES THOSE DAYS. PLAN
ON MILD TO MUGGY MORNINGS WITH READINGS IN THE UPPER 60S TO LOW 70S.
A WEAK CAP AND SUBSIDENCE ALOFT SHOULD PRECLUDE THE DEVELOPMENT OF
AFTERNOON/EVENING SHOWERS FOR THE MAJORITY OF FOLKS MOST
DAYS...HOWEVER GIVEN THE WARM TEMPERATURES AND MODEST DEWPOINTS
/MID 60S/...COULDN`T RULE OUT A STRAY SHOWER OR STORM. FOR
CONTINUITY...KEPT A VERY SLIGHT CHANCE IN THE FORECAST FOR SOUTHERN
INDIANA AND NORTHERN KENTUCKY WEDNESDAY. BY THIS WEEKEND...A MODEL
CONSENSUS SHOWS SLIGHT CHANCES OF SHOWER/STORMS...THOUGH WITH NO
REAL FORCING MECHANISM OR STRONG MOISTURE TRANSPORT THIS MAY BE
OVERDONE. A CONTINUATION OF DRY WEATHER COULD CONTINUE THROUGH
SUNDAY.
&&
.AVIATION (18Z TAF UPDATE)...
ISSUED AT 100 PM EDT MON AUG 31 2015
QUITE WEATHER EXPECTED AT THE TERMINALS THIS PERIOD. ONLY EXCEPTION
MAY BE SOME BRIEF REDUCTIONS IN VSBY AT KBWG/KLEX. ONLY HAVE ENOUGH
CONFIDENCE TO PUT IN A TEMPO GROUP AT KBWG. WILL WAIT AND SEE HOW
DRY THE AFTERNOON GETS AT KLEX BEFORE DEALING WITH THAT POTENTIAL
LATER.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
UPDATE.........RJS
SHORT TERM.....AMS
LONG TERM......ZBT
AVIATION.......RJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1159 AM EDT MON AUG 31 2015
...FORECAST UPDATE...
ISSUED AT 1155 AM EDT MON AUG 31 2015
GOES SOUNDER DATA INDICATE PRECIPITABLE WATER LEVELS ARE AROUND 1.3
INCHES...QUITE A BIT LESS THAN THIS TIME YESTERDAY. AMDAR SOUNDINGS
SHOW A PRETTY GOOD CAP AT 500 MB. LATEST RUC SOUNDINGS SHOW MORE PW
THAN WHAT THE GOES SOUNDER HAS. WITH THE DRYING OUT...MULTIPLE
MODELS SHOW LITTLE IN THE WAY OF PRECIP. DECIDED TO BACK OFF ON POPS
FOR ALL BUT OUR NORTHERN STRIPE OF COUNTIES IN INDIANA. REST OF THE
FORECAST LOOKS GOOD WITH LOUISVILLE METRO GETTING TO THE UPPER 80S
AND THE REST OF THE AREA IN THE MID 80S.
.SHORT TERM (NOW THROUGH TUESDAY)...
ISSUED AT 315 AM EDT MON AUG 31 2015
EARLY THIS MORNING SOME PATCHY FOG HAS DEVELOPED IN SPOTS. THINK WE
MAY SEE MORE DEVELOP ESPECIALLY IN AREAS THAT RECEIVED RAINFALL
YESTERDAY, SO WILL CONTINUE EARLY MORNING PATCHY FOG MENTION BUT
DON`T THINK FOG SHOULD BECOME DENSE OR WIDESPREAD. FOG SHOULD
DIMINISH SHORTLY AFTER SUNRISE.
FOR THE REST OF THE DAY, EXPECT PARTLY CLOUDY SKIES WITH ISOLATED
AFTERNOON/EVENING SHOWERS/STORMS DEVELOPING AGAIN. RIDGING WILL BE
ON THE INCREASE TODAY AND INHIBIT CONVECTION COVERAGE A LITTLE MORE
THAN YESTERDAY. THE MOST LIKELY LOCATIONS TO SEE AN ISLD SHOWER OR
STORM LOOK TO BE SOUTHERN INDIANA OR NORTH CENTRAL KY WHERE CAPPING
MAY BE WEAKER. EXPECT HIGH TEMPS TO BE SIMILAR TO YESTERDAY IN THE
MIDDLE 80S.
TONIGHT IS EXPECTED TO BE MAINLY DRY WITH ANY CONVECTION ENDING
DURING THE EVENING HOURS. RIDGING WILL CONTINUE TO INCREASE OVER
THE REGION WITH A GOOD MID LEVEL CAP NOTED IN SOUNDINGS FOR TUESDAY.
THEREFORE WILL KEEP TUES DRY. LOWS TONIGHT SHOULD RANGE FROM THE
MID 60S TO AROUND 70. HIGHS ON TUES WILL WARM INTO THE UPPER 80S TO
AROUND 90.
.LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...
ISSUED AT 258 AM EDT MON AUG 31 2015
THE MAIN STORY FOR THE LONG TERM PERIOD IS THE LIKELY HOT AND DRY
CONDITIONS AS WE HEAD INTO THE FIRST FULL WEEK OF SEPTEMBER AND THE
UPCOMING HOLIDAY WEEKEND.
THE 31.00Z GUIDANCE TRENDED TOWARD SIMILAR SOLUTIONS WITH REGARD TO
THE UPPER LEVEL PATTERN...SHOWING BUILDING HEIGHTS AND RIDGING
WEDNESDAY THROUGH THIS UPCOMING WEEKEND. AT THE SURFACE...THE REGION
WILL BE MOSTLY UNDER THE INFLUENCE OF HIGH PRESSURE.
SENSIBLE WEATHER INCLUDES SEASONABLY WARM TO HOT CONDITIONS AS
READINGS TOP OUT IN THE UPPER 80S TO LOW 90S EACH AFTERNOON. LOOKING
AT SOME OF THE EXTENDED ENSEMBLE MOS DATA...THURSDAY THROUGH
SATURDAY LOOK TO BE THE WARMEST...AND A FEW MID 90 READINGS ARE
POSSIBLE IN THE TYPICAL WARM SPOTS AND URBAN CORES THOSE DAYS. PLAN
ON MILD TO MUGGY MORNINGS WITH READINGS IN THE UPPER 60S TO LOW 70S.
A WEAK CAP AND SUBSIDENCE ALOFT SHOULD PRECLUDE THE DEVELOPMENT OF
AFTERNOON/EVENING SHOWERS FOR THE MAJORITY OF FOLKS MOST
DAYS...HOWEVER GIVEN THE WARM TEMPERATURES AND MODEST DEWPOINTS
/MID 60S/...COULDN`T RULE OUT A STRAY SHOWER OR STORM. FOR
CONTINUITY...KEPT A VERY SLIGHT CHANCE IN THE FORECAST FOR SOUTHERN
INDIANA AND NORTHERN KENTUCKY WEDNESDAY. BY THIS WEEKEND...A MODEL
CONSENSUS SHOWS SLIGHT CHANCES OF SHOWER/STORMS...THOUGH WITH NO
REAL FORCING MECHANISM OR STRONG MOISTURE TRANSPORT THIS MAY BE
OVERDONE. A CONTINUATION OF DRY WEATHER COULD CONTINUE THROUGH
SUNDAY.
&&
.AVIATION (12Z TAF UPDATE)...
ISSUED AT 645 AM EDT MON AUG 31 2015
SOME LIGHT BR AT BWG WILL BE THE MAIN TAF CONCERN. WITH LIGHT WINDS
AND DECENT LOW LEVEL MOISTURE BWG HAS DIPPED INTO THE IFR CAT AND
MAY CONTINUE TO DO SO FOR THE NEXT HOUR OR TWO. WINDS WILL BECOME
SWW DURING THE DAYLIGHT HOURS WITH SOME AFTERNOON CU EXPECTED. A
STRAY SHOWER/STORM CANNOT BE RULED OUT THIS AFTERNOON/EVENING BUT
FEEL THAT CHANCES ARE TOO SLIM TO INCLUDE IN THE TAFS. SKIES WILL
BECOME MOSTLY CLEAR FOR TONIGHT WITH LIGHT AND VRB WINDS.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
UPDATE.........RJS
SHORT TERM.....AMS
LONG TERM......ZBT
AVIATION.......AMS
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1137 PM EDT TUE SEP 1 2015
.UPDATE...
ISSUED AT 1106 PM EDT TUE SEP 1 2015
HIGH PRESSURE REMAINS FIXED ACROSS MUCH OF THE EASTERN CONUS WITH
RETURN FLOW OF WARMTH AND MOISTURE (AND INSTABILITY) FROM THE
PLAINS INTO THE WESTERN GREAT LAKES. MEANWHILE...LOW PRESSURE IN
NRN QUEBEC HAS A COLD FRONT STRETCHING DOWN THROUGH ONTARIO AND
BISECTING LAKE SUPERIOR...THEN BACK THROUGH WISCONSIN INTO
MINNESOTA. A COUPLE WAVES ALONG THE FRONT...ONE JUST NORTHEAST OF
LAKE SUPERIOR SPURRING ON LINE OF SHOWERS/STORMS UP THAT WAY.
SECOND WAVE IS PUSHING INTO MINNESOTA AND WILL BE PUSHING THROUGH
NRN MICHIGAN LATER TOMORROW.
REST OF TONIGHT...SHOULD REMAIN QUIET AND FAIRLY MILD (STILL 77 AT
TVC AT 11 PM...SUMMER). WEAK FRONT WILL SLIP DOWN INTO NRN MICHIGAN
BUT IT SEEMS WITH LITTLE FANFARE. GIVEN THE WARM/JUICY AIRMASS
OUT THERE SUPPOSE IT/S NOT IMPOSSIBLE WE COULD SEE SOMETHING
DEVELOP. BUT WILL MAINTAIN THE DRY FORECAST AT THIS POINT.
OTHERWISE...RECENT OBS STARTING TO SHOW SOME VSBY REDUCTIONS...AND
WE SHOULD SEE A FAIR AMOUNT OF FOG DEVELOPMENT THROUGH THE BALANCE
OF THE NIGHT.
UPDATE ISSUED AT 816 PM EDT TUE SEP 1 2015
BUBBLY CU HAS DIMINISHED QUICKLY OVER THE LAST FEW HOURS. WEAK
FRONT CONTINUES TO SLIP EAST ACROSS CENTRAL UPPER MICHIGAN...BUT
ALL PRECIP ALONG THE FRONT HAS PUSHED UP INTO ONTARIO. SO...IT
APPEARS AT LEAST...THAT ANY SHOWER/TSTM CHANCES ARE MINIMAL AT
THIS JUNCTURE. HAVE THUS REMOVED FROM THE FORECAST FOR THE BALANCE
OF THE EVENING.
&&
.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 331 PM EDT TUE SEP 1 2015
WARM AND VERY HUMID OUT THERE THIS AFTERNOON. DEW POINTS SPIKED
INTO THE LOWER 70S IN MOST LOCALES AT MIDDAY...BUT HAVE MIXING OUT
A TOUCH HERE AT MID-AFTERNOON. TEMPS ARE IN THE 80S...SOME 70S IN
MACKINAC AND SE CHIPPEWA COS. CU FIELD IS UNIMPRESSIVE ACROSS
NORTHERN LOWER/EASTERN UPPER MI. MORE VIGOROUS CU IS SEEN IN
EASTERN WI AND THE WEST HALF OF UPPER MI...WHERE DEW POINTS ARE IN
THE LOW AND EVEN MID 70S IN SPOTS. HOWEVER...SHRA/TSRA ARE NOT YET
EVIDENT...OUTSIDE OF SOME WEAKENING SHRA NEAR THE KEWEENAW. THESE
ARE ASSOCIATED WITH A WEAKENING COLD FRONT/WIND SHIFT BOUNDARY
CROSSING WESTERN/CENTRAL SUPERIOR.
THERE IS SOME POTENTIAL FOR SHRA/TSRA TO INCREASE IN THE VICINITY
OF S CENTRAL SUPERIOR BY EARLY EVENING...AS THE INCOMING BOUNDARY
INTERCEPTS THE INSTABILITY PLUME (MLCAPES TO 2K J/KG) POKING INTO
CENTRAL UPPER MI. HI-RES SHORT TERM MODELS ARE OF MIXED OPINIONS
AS TO WHETHER/HOW THIS WILL PLAY OUT. NAM/NSSL-WRF FAVOR BRINGING
CONVECTION INTO EASTERN UPPER MI THIS EVENING. BUT MOST OF THESE
ARE ALREADY BUBBLING OF DEEP CONVECTION NOW...WHICH IS NOT
HAPPENING. SPC HRRR OFFERS PERHAPS THE MOST REALISTIC SOLUTION...
GENERATING CONVECTION NORTH OF MQT AS THE UNSTABLE PLUME LIFTS
OVER THE SUPERIOR COLD DOME...THEN LARGELY KEEPING IT OVER THE BIG
LAKE AS IT MOVES EAST. WAS GIVING SERIOUS THOUGHT EARLIER TO
BOOSTING POPS...BUT LOOKING AT CURRENT CONDITIONS AND MODEL PROGS
HAVE DECIDED THAT CAN/T FAVOR ANYTHING MORE THAN A 20 POP. WILL
MAINTAIN THAT SLIGHT CHANCE IN WESTERN/CENTRAL CHIP/MACK COUNTIES
THRU THIS EVENING.
OTHERWISE...ANOTHER NIGHT WITH AREAS OF FOG. PERHAPS NOT QUITE AS
MUCH AS THIS MORNING (WHICH WAS LESS THAN THE MORNING
BEFORE)...THANKS TO STRONG MIXING AND RESULTING DECREASE IN DEW
POINTS THIS AFTERNOON. STILL AN UNSEASONABLY WARM/STICKY
NIGHT...WITH MINS IN THE MID 60S TO AROUND 70F.
&&
.SHORT TERM...(WEDNESDAY THROUGH FRIDAY)
ISSUED AT 331 PM EDT TUE SEP 1 2015
WEDNESDAY THROUGH FRIDAY....THE LARGE AREA OF HIGH PRESSURE WHICH
HAS BEEN IN PLACE ACROSS THE ERN ONE THIRD OF THE COUNTRY...WILL
REMAIN ANCHORED OVER THE MID ATLANTIC INTO THE UPCOMING WEEKEND. AT
UPPER LVLS...A STRONG 500MB RIDGE ANCHORED OVER THE GULF STATES AND
OHIO VALLEY...WILL CONTINUE TO NUDGE INTO THE GREAT LAKES THROUGH
THE FORECAST PERIOD. MID LVL TEMPS ASSOCIATED WITH THIS UPPER LVL
PATTERN WILL BE WELL ABOVE NORMAL ACRS THE GREAT LAKES INTO THE
UPCOMING WEEKEND...REMAINING AROUND 16C/17C. THIS OVERALL SFC AND
UPPER LVL PATTERN WILL CONTINUE SUMMER LIKE WEATHER...WITH WELL
ABOVE NORMAL TEMPS ACRS NRN MI THROUGH THE END OF THE WORK WEEK.
WILL CONTINUE AT LEAST A PARTLY SUNNY TREND ACROSS THE REGION AS
MODEL SOUNDINGS AND MSTR PROGS SHOW LIMITED MSTR THROUGH THE
COLUMN...WITH 850/500MB RH AROUND 40/60 PCT THROUGH THE FCST PERIOD.
HOWEVER ENOUGH LOW LVL MSTR WILL BE PRESENT TO CONTINUE MUGGY CONDS
ACRS NRN MI...WITH SFC DEW PTS IN THE MID AND UPPER 60S WHILE MID
LVL DEW PTS REMAIN 12C OR GREATER. WILL CONTINUE WITH MAINLY DRY
CONDITIONS ACROSS NRN MI THOUGH A CHANCE OF PCPN EXIST WEDNESDAY
AFTERNOON AND THURSDAY...THE RESULT OF A WEAK RIPPLE IN THE UPPER
FLOW. 850/500MB QVECTORS SHOW SIGNIFICANT ENOUGH CONVERGENCE WITH
APPROACHING 500MB TROUGH WEDNESDAY AND THURSDAY TO GENERATE PCPN
ACRS NRN MI. MODEL SOUNDINGS SHOWING ENOUGH LOW AND MID LVL MSTR
(SFC DW PTS IN THE UPPER 60S) AND INSTABILITY (LI ARND -4C, MU CAPE
BETWEEN 2000 AND 3000 J/KG, 850/500MB LAPSE RATES INCREASING TO 7
C/KM) TO MENTION THUNDERSTORMS WEDNESDAY NIGHT AND THURSDAY IN THE
FORECAST.
&&
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 331 PM EDT TUE SEP 1 2015
HEAT WILL CONTINUE TO BE THE MAIN STORY GOING INTO LABOR DAY...WITH
WELL ABOVE NORMAL TEMPERATURES ACROSS THE FORECAST AREA. A COLD
FRONT ARRIVING EARLY IN THE WEEK WILL FLATTEN OUT THE H5 RIDGING AND
RETURN TEMPERATURES CLOSER TO...THOUGH STILL SLIGHTLY ABOVE...NORMAL
BY THE END OF THE EXTENDED PERIOD. THERE WILL BE A SMALL CHANCE FOR
SOME SCATTERED THUNDERSTORMS THROUGH THE WEEKEND...BUT AS MENTIONED
BY THE PREVIOUS SHIFT...SUBSIDENCE UNDER THE HIGH PRESSURE COULD
HOLD THOSE OFF. THE BETTER CHANCE FOR SHOWERS WILL BE ASSOCIATED
WITH THE EARLY WEEK COLD FRONT...WHICH IS STILL ALL OVER THE PLACE
AS FAR AS TIMING AND PLACEMENT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1137 PM EDT TUE SEP 1 2015
LIGHT WINDS/HIGH SFC DEWPOINTS AND MAINLY CLEAR SKIES WILL LEAD
TO FOG ISSUES OVERNIGHT. JUST A MATTER OF TIMING...BUT MVFR TO
IFR VSBYS ARE ANTICIPATED WITH PLN/MBL THE MOST LIKELY
CANDIDATES FOR IFR CONDITIONS.
WEDNESDAY...MORNING FOG WILL BURN OFF BY 14Z. ANOTHER WARM AND
EVEN MORE HUMID DAY IN STORE FOR NRN LOWER MICHIGAN. THIS WILL
LEAD TO AFTERNOON TSTM POSSIBILITIES AND MOST LIKELY ACROSS NE
LOWER MICHIGAN IMPACTING THE APN TERMINAL SITE. CONVECTION SHOULD
WANE INTO THE EVENING. BUT ADDITIONAL FOG DEVELOPMENT IS POSSIBLE
LATER TOMORROW EVENING AND OVERNIGHT.
&&
.MARINE...
ISSUED AT 331 PM EDT TUE SEP 1 2015
SW WINDS WILL CONTINUE...AROUND HIGH PRESSURE TO OUR SE. WINDS
WILL BE ENOUGH TO KEEP THE NORTH END OF LAKE MI A LITTLE
BUMPY...IN THE 2-4 FT RANGE...BUT SHORT OF ADVISORY CRITERIA.
AREAS OF MARINE FOG/STRATUS WILL ALSO CONTINUE...THANKS TO THE
HUMID AIR IN PLACE.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...ADAM
NEAR TERM...JAZ
SHORT TERM...SWR
LONG TERM...ALM
AVIATION...ADAM
MARINE...JAZ
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1106 PM EDT TUE SEP 1 2015
.UPDATE...
ISSUED AT 1106 PM EDT TUE SEP 1 2015
HIGH PRESSURE REMAINS FIXED ACROSS MUCH OF THE EASTERN CONUS WITH
RETURN FLOW OF WARMTH AND MOISTURE (AND INSTABILITY) FROM THE
PLAINS INTO THE WESTERN GREAT LAKES. MEANWHILE...LOW PRESSURE IN
NRN QUEBEC HAS A COLD FRONT STRETCHING DOWN THROUGH ONTARIO AND
BISECTING LAKE SUPERIOR...THEN BACK THROUGH WISCONSIN INTO
MINNESOTA. A COUPLE WAVES ALONG THE FRONT...ONE JUST NORTHEAST OF
LAKE SUPERIOR SPURRING ON LINE OF SHOWERS/STORMS UP THAT WAY.
SECOND WAVE IS PUSHING INTO MINNESOTA AND WILL BE PUSHING THROUGH
NRN MICHIGAN LATER TOMORROW.
REST OF TONIGHT...SHOULD REMAIN QUIET AND FAIRLY MILD (STILL 77 AT
TVC AT 11 PM...SUMMER). WEAK FRONT WILL SLIP DOWN INTO NRN MICHIGAN
BUT IT SEEMS WITH LITTLE FANFARE. GIVEN THE WARM/JUICY AIRMASS
OUT THERE SUPPOSE IT/S NOT IMPOSSIBLE WE COULD SEE SOMETHING
DEVELOP. BUT WILL MAINTAIN THE DRY FORECAST AT THIS POINT.
OTHERWISE...RECENT OBS STARTING TO SHOW SOME VSBY REDUCTIONS...AND
WE SHOULD SEE A FAIR AMOUNT OF FOG DEVELOPMENT THROUGH THE BALANCE
OF THE NIGHT.
UPDATE ISSUED AT 816 PM EDT TUE SEP 1 2015
BUBBLY CU HAS DIMINISHED QUICKLY OVER THE LAST FEW HOURS. WEAK
FRONT CONTINUES TO SLIP EAST ACROSS CENTRAL UPPER MICHIGAN...BUT
ALL PRECIP ALONG THE FRONT HAS PUSHED UP INTO ONTARIO. SO...IT
APPEARS AT LEAST...THAT ANY SHOWER/TSTM CHANCES ARE MINIMAL AT
THIS JUNCTURE. HAVE THUS REMOVED FROM THE FORECAST FOR THE BALANCE
OF THE EVENING.
&&
.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 331 PM EDT TUE SEP 1 2015
WARM AND VERY HUMID OUT THERE THIS AFTERNOON. DEW POINTS SPIKED
INTO THE LOWER 70S IN MOST LOCALES AT MIDDAY...BUT HAVE MIXING OUT
A TOUCH HERE AT MID-AFTERNOON. TEMPS ARE IN THE 80S...SOME 70S IN
MACKINAC AND SE CHIPPEWA COS. CU FIELD IS UNIMPRESSIVE ACROSS
NORTHERN LOWER/EASTERN UPPER MI. MORE VIGOROUS CU IS SEEN IN
EASTERN WI AND THE WEST HALF OF UPPER MI...WHERE DEW POINTS ARE IN
THE LOW AND EVEN MID 70S IN SPOTS. HOWEVER...SHRA/TSRA ARE NOT YET
EVIDENT...OUTSIDE OF SOME WEAKENING SHRA NEAR THE KEWEENAW. THESE
ARE ASSOCIATED WITH A WEAKENING COLD FRONT/WIND SHIFT BOUNDARY
CROSSING WESTERN/CENTRAL SUPERIOR.
THERE IS SOME POTENTIAL FOR SHRA/TSRA TO INCREASE IN THE VICINITY
OF S CENTRAL SUPERIOR BY EARLY EVENING...AS THE INCOMING BOUNDARY
INTERCEPTS THE INSTABILITY PLUME (MLCAPES TO 2K J/KG) POKING INTO
CENTRAL UPPER MI. HI-RES SHORT TERM MODELS ARE OF MIXED OPINIONS
AS TO WHETHER/HOW THIS WILL PLAY OUT. NAM/NSSL-WRF FAVOR BRINGING
CONVECTION INTO EASTERN UPPER MI THIS EVENING. BUT MOST OF THESE
ARE ALREADY BUBBLING OF DEEP CONVECTION NOW...WHICH IS NOT
HAPPENING. SPC HRRR OFFERS PERHAPS THE MOST REALISTIC SOLUTION...
GENERATING CONVECTION NORTH OF MQT AS THE UNSTABLE PLUME LIFTS
OVER THE SUPERIOR COLD DOME...THEN LARGELY KEEPING IT OVER THE BIG
LAKE AS IT MOVES EAST. WAS GIVING SERIOUS THOUGHT EARLIER TO
BOOSTING POPS...BUT LOOKING AT CURRENT CONDITIONS AND MODEL PROGS
HAVE DECIDED THAT CAN/T FAVOR ANYTHING MORE THAN A 20 POP. WILL
MAINTAIN THAT SLIGHT CHANCE IN WESTERN/CENTRAL CHIP/MACK COUNTIES
THRU THIS EVENING.
OTHERWISE...ANOTHER NIGHT WITH AREAS OF FOG. PERHAPS NOT QUITE AS
MUCH AS THIS MORNING (WHICH WAS LESS THAN THE MORNING
BEFORE)...THANKS TO STRONG MIXING AND RESULTING DECREASE IN DEW
POINTS THIS AFTERNOON. STILL AN UNSEASONABLY WARM/STICKY
NIGHT...WITH MINS IN THE MID 60S TO AROUND 70F.
&&
.SHORT TERM...(WEDNESDAY THROUGH FRIDAY)
ISSUED AT 331 PM EDT TUE SEP 1 2015
WEDNESDAY THROUGH FRIDAY....THE LARGE AREA OF HIGH PRESSURE WHICH
HAS BEEN IN PLACE ACROSS THE ERN ONE THIRD OF THE COUNTRY...WILL
REMAIN ANCHORED OVER THE MID ATLANTIC INTO THE UPCOMING WEEKEND. AT
UPPER LVLS...A STRONG 500MB RIDGE ANCHORED OVER THE GULF STATES AND
OHIO VALLEY...WILL CONTINUE TO NUDGE INTO THE GREAT LAKES THROUGH
THE FORECAST PERIOD. MID LVL TEMPS ASSOCIATED WITH THIS UPPER LVL
PATTERN WILL BE WELL ABOVE NORMAL ACRS THE GREAT LAKES INTO THE
UPCOMING WEEKEND...REMAINING AROUND 16C/17C. THIS OVERALL SFC AND
UPPER LVL PATTERN WILL CONTINUE SUMMER LIKE WEATHER...WITH WELL
ABOVE NORMAL TEMPS ACRS NRN MI THROUGH THE END OF THE WORK WEEK.
WILL CONTINUE AT LEAST A PARTLY SUNNY TREND ACROSS THE REGION AS
MODEL SOUNDINGS AND MSTR PROGS SHOW LIMITED MSTR THROUGH THE
COLUMN...WITH 850/500MB RH AROUND 40/60 PCT THROUGH THE FCST PERIOD.
HOWEVER ENOUGH LOW LVL MSTR WILL BE PRESENT TO CONTINUE MUGGY CONDS
ACRS NRN MI...WITH SFC DEW PTS IN THE MID AND UPPER 60S WHILE MID
LVL DEW PTS REMAIN 12C OR GREATER. WILL CONTINUE WITH MAINLY DRY
CONDITIONS ACROSS NRN MI THOUGH A CHANCE OF PCPN EXIST WEDNESDAY
AFTERNOON AND THURSDAY...THE RESULT OF A WEAK RIPPLE IN THE UPPER
FLOW. 850/500MB QVECTORS SHOW SIGNIFICANT ENOUGH CONVERGENCE WITH
APPROACHING 500MB TROUGH WEDNESDAY AND THURSDAY TO GENERATE PCPN
ACRS NRN MI. MODEL SOUNDINGS SHOWING ENOUGH LOW AND MID LVL MSTR
(SFC DW PTS IN THE UPPER 60S) AND INSTABILITY (LI ARND -4C, MU CAPE
BETWEEN 2000 AND 3000 J/KG, 850/500MB LAPSE RATES INCREASING TO 7
C/KM) TO MENTION THUNDERSTORMS WEDNESDAY NIGHT AND THURSDAY IN THE
FORECAST.
&&
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 331 PM EDT TUE SEP 1 2015
HEAT WILL CONTINUE TO BE THE MAIN STORY GOING INTO LABOR DAY...WITH
WELL ABOVE NORMAL TEMPERATURES ACROSS THE FORECAST AREA. A COLD
FRONT ARRIVING EARLY IN THE WEEK WILL FLATTEN OUT THE H5 RIDGING AND
RETURN TEMPERATURES CLOSER TO...THOUGH STILL SLIGHTLY ABOVE...NORMAL
BY THE END OF THE EXTENDED PERIOD. THERE WILL BE A SMALL CHANCE FOR
SOME SCATTERED THUNDERSTORMS THROUGH THE WEEKEND...BUT AS MENTIONED
BY THE PREVIOUS SHIFT...SUBSIDENCE UNDER THE HIGH PRESSURE COULD
HOLD THOSE OFF. THE BETTER CHANCE FOR SHOWERS WILL BE ASSOCIATED
WITH THE EARLY WEEK COLD FRONT...WHICH IS STILL ALL OVER THE PLACE
AS FAR AS TIMING AND PLACEMENT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 816 PM EDT TUE SEP 1 2015
SOLID VFR CONDITIONS OUT THERE FOR THE TIME BEING. BUT A FAIRLY MOIST
BOUNDARY LAYER (SFC DEWPOINTS UP NEAR 70) WILL LEAD TO FOG ISSUES
LATER ON TONIGHT. THAT SAID...TEMPS ARE STILL UP NEAR 80 IN MANY
LOCATIONS AT IT WILL TAKE A FEW HOURS FOR TEMPS TO FALL ENOUGH TO
START SEEING VSBY REDUCTIONS. SO...HAVE BACKED OFF TIMING OF MVFR
VSBYS BY A FEW HOURS VS PREVIOUS TAF FORECASTS. EVENTUALLY...IFR
VSBYS WILL PROBABLY MATERIALIZE AT SOME OF THE TERMINAL SITES
(PLN/APN/MBL THE MOST LIKELY CANDIDATES).
WEDNESDAY...MORNING FOG WILL BURN OFF BY 14Z. ANOTHER WARM AND
EVEN MORE HUMID DAY IN STORE FOR NRN LOWER MICHIGAN. THIS WILL
LEAD TO AFTERNOON TSTM POSSIBILITIES. MOST LIKELY LOCATION LOOKING
TO BE ACROSS NE LOWER MICHIGAN AND IMPACTING THE APN TERMINAL
SITE. HAVE NOT EXPLICITLY INCLUDED TSTM IN THE FORECAST YET...BUT
PLAN ACCORDINGLY.
&&
.MARINE...
ISSUED AT 331 PM EDT TUE SEP 1 2015
SW WINDS WILL CONTINUE...AROUND HIGH PRESSURE TO OUR SE. WINDS
WILL BE ENOUGH TO KEEP THE NORTH END OF LAKE MI A LITTLE
BUMPY...IN THE 2-4 FT RANGE...BUT SHORT OF ADVISORY CRITERIA.
AREAS OF MARINE FOG/STRATUS WILL ALSO CONTINUE...THANKS TO THE
HUMID AIR IN PLACE.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...ADAM
NEAR TERM...JAZ
SHORT TERM...SWR
LONG TERM...ALM
AVIATION...ADAM
MARINE...JAZ
AREA FORECAST DISCUSSION
NWS GAYLORD MI
817 PM EDT TUE SEP 1 2015
.UPDATE...
ISSUED AT 816 PM EDT TUE SEP 1 2015
BUBBLY CU HAS DIMINISHED QUICKLY OVER THE LAST FEW HOURS. WEAK
FRONT CONTINUES TO SLIP EAST ACROSS CENTRAL UPPER MICHIGAN...BUT
ALL PRECIP ALONG THE FRONT HAS PUSHED UP INTO ONTARIO. SO...IT
APPEARS AT LEAST...THAT ANY SHOWER/TSTM CHANCES ARE MINIMAL AT
THIS JUNCTURE. HAVE THUS REMOVED FROM THE FORECAST FOR THE BALANCE
OF THE EVENING.
&&
.NEAR TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 331 PM EDT TUE SEP 1 2015
WARM AND VERY HUMID OUT THERE THIS AFTERNOON. DEW POINTS SPIKED
INTO THE LOWER 70S IN MOST LOCALES AT MIDDAY...BUT HAVE MIXING OUT
A TOUCH HERE AT MID-AFTERNOON. TEMPS ARE IN THE 80S...SOME 70S IN
MACKINAC AND SE CHIPPEWA COS. CU FIELD IS UNIMPRESSIVE ACROSS
NORTHERN LOWER/EASTERN UPPER MI. MORE VIGOROUS CU IS SEEN IN
EASTERN WI AND THE WEST HALF OF UPPER MI...WHERE DEW POINTS ARE IN
THE LOW AND EVEN MID 70S IN SPOTS. HOWEVER...SHRA/TSRA ARE NOT YET
EVIDENT...OUTSIDE OF SOME WEAKENING SHRA NEAR THE KEWEENAW. THESE
ARE ASSOCIATED WITH A WEAKENING COLD FRONT/WIND SHIFT BOUNDARY
CROSSING WESTERN/CENTRAL SUPERIOR.
THERE IS SOME POTENTIAL FOR SHRA/TSRA TO INCREASE IN THE VICINITY
OF S CENTRAL SUPERIOR BY EARLY EVENING...AS THE INCOMING BOUNDARY
INTERCEPTS THE INSTABILITY PLUME (MLCAPES TO 2K J/KG) POKING INTO
CENTRAL UPPER MI. HI-RES SHORT TERM MODELS ARE OF MIXED OPINIONS
AS TO WHETHER/HOW THIS WILL PLAY OUT. NAM/NSSL-WRF FAVOR BRINGING
CONVECTION INTO EASTERN UPPER MI THIS EVENING. BUT MOST OF THESE
ARE ALREADY BUBBLING OF DEEP CONVECTION NOW...WHICH IS NOT
HAPPENING. SPC HRRR OFFERS PERHAPS THE MOST REALISTIC SOLUTION...
GENERATING CONVECTION NORTH OF MQT AS THE UNSTABLE PLUME LIFTS
OVER THE SUPERIOR COLD DOME...THEN LARGELY KEEPING IT OVER THE BIG
LAKE AS IT MOVES EAST. WAS GIVING SERIOUS THOUGHT EARLIER TO
BOOSTING POPS...BUT LOOKING AT CURRENT CONDITIONS AND MODEL PROGS
HAVE DECIDED THAT CAN/T FAVOR ANYTHING MORE THAN A 20 POP. WILL
MAINTAIN THAT SLIGHT CHANCE IN WESTERN/CENTRAL CHIP/MACK COUNTIES
THRU THIS EVENING.
OTHERWISE...ANOTHER NIGHT WITH AREAS OF FOG. PERHAPS NOT QUITE AS
MUCH AS THIS MORNING (WHICH WAS LESS THAN THE MORNING
BEFORE)...THANKS TO STRONG MIXING AND RESULTING DECREASE IN DEW
POINTS THIS AFTERNOON. STILL AN UNSEASONABLY WARM/STICKY
NIGHT...WITH MINS IN THE MID 60S TO AROUND 70F.
&&
.SHORT TERM...(WEDNESDAY THROUGH FRIDAY)
ISSUED AT 331 PM EDT TUE SEP 1 2015
WEDNESDAY THROUGH FRIDAY....THE LARGE AREA OF HIGH PRESSURE WHICH
HAS BEEN IN PLACE ACROSS THE ERN ONE THIRD OF THE COUNTRY...WILL
REMAIN ANCHORED OVER THE MID ATLANTIC INTO THE UPCOMING WEEKEND. AT
UPPER LVLS...A STRONG 500MB RIDGE ANCHORED OVER THE GULF STATES AND
OHIO VALLEY...WILL CONTINUE TO NUDGE INTO THE GREAT LAKES THROUGH
THE FORECAST PERIOD. MID LVL TEMPS ASSOCIATED WITH THIS UPPER LVL
PATTERN WILL BE WELL ABOVE NORMAL ACRS THE GREAT LAKES INTO THE
UPCOMING WEEKEND...REMAINING AROUND 16C/17C. THIS OVERALL SFC AND
UPPER LVL PATTERN WILL CONTINUE SUMMER LIKE WEATHER...WITH WELL
ABOVE NORMAL TEMPS ACRS NRN MI THROUGH THE END OF THE WORK WEEK.
WILL CONTINUE AT LEAST A PARTLY SUNNY TREND ACROSS THE REGION AS
MODEL SOUNDINGS AND MSTR PROGS SHOW LIMITED MSTR THROUGH THE
COLUMN...WITH 850/500MB RH AROUND 40/60 PCT THROUGH THE FCST PERIOD.
HOWEVER ENOUGH LOW LVL MSTR WILL BE PRESENT TO CONTINUE MUGGY CONDS
ACRS NRN MI...WITH SFC DEW PTS IN THE MID AND UPPER 60S WHILE MID
LVL DEW PTS REMAIN 12C OR GREATER. WILL CONTINUE WITH MAINLY DRY
CONDITIONS ACROSS NRN MI THOUGH A CHANCE OF PCPN EXIST WEDNESDAY
AFTERNOON AND THURSDAY...THE RESULT OF A WEAK RIPPLE IN THE UPPER
FLOW. 850/500MB QVECTORS SHOW SIGNIFICANT ENOUGH CONVERGENCE WITH
APPROACHING 500MB TROUGH WEDNESDAY AND THURSDAY TO GENERATE PCPN
ACRS NRN MI. MODEL SOUNDINGS SHOWING ENOUGH LOW AND MID LVL MSTR
(SFC DW PTS IN THE UPPER 60S) AND INSTABILITY (LI ARND -4C, MU CAPE
BETWEEN 2000 AND 3000 J/KG, 850/500MB LAPSE RATES INCREASING TO 7
C/KM) TO MENTION THUNDERSTORMS WEDNESDAY NIGHT AND THURSDAY IN THE
FORECAST.
&&
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 331 PM EDT TUE SEP 1 2015
HEAT WILL CONTINUE TO BE THE MAIN STORY GOING INTO LABOR DAY...WITH
WELL ABOVE NORMAL TEMPERATURES ACROSS THE FORECAST AREA. A COLD
FRONT ARRIVING EARLY IN THE WEEK WILL FLATTEN OUT THE H5 RIDGING AND
RETURN TEMPERATURES CLOSER TO...THOUGH STILL SLIGHTLY ABOVE...NORMAL
BY THE END OF THE EXTENDED PERIOD. THERE WILL BE A SMALL CHANCE FOR
SOME SCATTERED THUNDERSTORMS THROUGH THE WEEKEND...BUT AS MENTIONED
BY THE PREVIOUS SHIFT...SUBSIDENCE UNDER THE HIGH PRESSURE COULD
HOLD THOSE OFF. THE BETTER CHANCE FOR SHOWERS WILL BE ASSOCIATED
WITH THE EARLY WEEK COLD FRONT...WHICH IS STILL ALL OVER THE PLACE
AS FAR AS TIMING AND PLACEMENT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 816 PM EDT TUE SEP 1 2015
SOLID VFR CONDITIONS OUT THERE FOR THE TIME BEING. BUT A FAIRLY MOIST
BOUNDARY LAYER (SFC DEWPOINTS UP NEAR 70) WILL LEAD TO FOG ISSUES
LATER ON TONIGHT. THAT SAID...TEMPS ARE STILL UP NEAR 80 IN MANY
LOCATIONS AT IT WILL TAKE A FEW HOURS FOR TEMPS TO FALL ENOUGH TO
START SEEING VSBY REDUCTIONS. SO...HAVE BACKED OFF TIMING OF MVFR
VSBYS BY A FEW HOURS VS PREVIOUS TAF FORECASTS. EVENTUALLY...IFR
VSBYS WILL PROBABLY MATERIALIZE AT SOME OF THE TERMINAL SITES
(PLN/APN/MBL THE MOST LIKELY CANDIDATES).
WEDNESDAY...MORNING FOG WILL BURN OFF BY 14Z. ANOTHER WARM AND
EVEN MORE HUMID DAY IN STORE FOR NRN LOWER MICHIGAN. THIS WILL
LEAD TO AFTERNOON TSTM POSSIBILITIES. MOST LIKELY LOCATION LOOKING
TO BE ACROSS NE LOWER MICHIGAN AND IMPACTING THE APN TERMINAL
SITE. HAVE NOT EXPLICITLY INCLUDED TSTM IN THE FORECAST YET...BUT
PLAN ACCORDINGLY.
&&
.MARINE...
ISSUED AT 331 PM EDT TUE SEP 1 2015
SW WINDS WILL CONTINUE...AROUND HIGH PRESSURE TO OUR SE. WINDS
WILL BE ENOUGH TO KEEP THE NORTH END OF LAKE MI A LITTLE
BUMPY...IN THE 2-4 FT RANGE...BUT SHORT OF ADVISORY CRITERIA.
AREAS OF MARINE FOG/STRATUS WILL ALSO CONTINUE...THANKS TO THE
HUMID AIR IN PLACE.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...ADAM
NEAR TERM...JAZ
SHORT TERM...SWR
LONG TERM...ALM
AVIATION...ADAM
MARINE...JAZ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
721 PM EDT TUE SEP 1 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 438 PM EDT TUE SEP 1 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW WSW FLOW INTO THE UPPER
GREAT LAKES. SOME DISTURBANCES ARE NOTED IN THE FLOW...ONE IS IN NE
MN AND THE OTHERS ARE IN SE SD/NE NEBRASKA. DESPITE PRESENCE OF
SHORTWAVE NEARBY AND MLCAPES OF 1500-2500J/KG...NO SHRA OR TSTMS
HAVE DEVELOPED YET THIS AFTN. PER VIS SATELLITE IMAGERY...THERE IS
AN AREA OF WHAT LOOKS LIKE ENHANCED CU DEVELOPMENT FROM MENOMINEE
COUNTY TO ERN MARQUETTE COUNTY AND THEN E TO NRN LUCE COUNTY IN
VCNTY OF LAKE BREEZE OFF LAKE MICHIGAN. TO THE W...SCT
-SHRA/SPRINKLES THAT WERE NEAR/JUST OFFSHORE OF WRN UPPER MI THIS
MORNING HAVE MADE LITTLE EASTWARD PROGRESS AND ARE DIMINISHING IN
COVERAGE. IT`S BEEN ANOTHER UNCOMFORTABLY HOT/HUMID DAY. DWPTS RANGE
FROM THE MID 60S TO LWR 70S WITH TEMPS GENERALLY BTWN 80F AND 90F.
COOLEST CONDITIONS (UPPER 60S/LWR 70S) ARE AT LAKESIDE LOCATIONS
ALONG LAKE MICHIGAN E OF KESC.
WITH THE LACK OF CONVECTION SO FAR THIS AFTN...POTENTIAL FOR
SHRA/TSTM DEVELOPMENT DOESN`T LOOK PROMISING. IF SHRA/TSTMS DO
FORM...IT LOOKS LIKE THE BEST POTENTIAL WILL BE IN THE VCNTY OF THE
LAKE MICHIGAN LAKE BREEZE WHERE CU LOOKS BETTER DEVELOPED ATTM.
RECENT HRRR RUNS POINT TOWARD THAT POSSIBILITY. NOTHING MUCH HIGHER
THAN SCHC POPS WILL UTILIZED INTO THE EARLY EVENING HRS. UPSTREAM
SHORTWAVES OVER SD/NEBRASKA WILL DRIFT NE DURING THE NIGHT...AND
PROBABLY SHOULDN`T POSE A RISK FOR PCPN OVERNIGHT. SOME OF THE DRIER
AIR IN NRN MN WHERE DWPTS HAVE DROPPED OFF AS LOW AS THE UPPER 40S
WILL TRY TO MAKE SOME INROADS INTO UPPER MI DURING THE NIGHT...BUT
GIVEN WEAK LOW-LEVEL WIND FIELDS AND AREAS OF FOG OVER LAKE
SUPERIOR...LITTLE OR NONE OF THIS DRIER AIR SHOULD BE REALIZED HERE.
END RESULT...SHOULD BE ANOTHER NIGHT WITH FOG AND STRATUS
DEVELOPMENT IN MANY AREAS.
IT APPEARS THAT WITH UPSTREAM SHORTWAVES MOVING INTO WI/UPPER MI
WED...THERE SHOULD BE A BETTER POTENTIAL OF SHRA/TSTM DEVELOPMENT.
AS OPPOSED TO THE PCPN POTENTIAL TODAY...MODEL CONSENSUS IS MUCH
BETTER FOR SOME PCPN TO OCCUR ON WED...MAINLY OVER THE INTERIOR W
HALF WHERE INSTABILITY WILL BE GREATER. FOR NOW...OPTED TO RAISE
POPS INTO THE LOW/MID RANGE CHC CATEGORY TOWARD THE WI BORDER. IT
WILL BE A LITTLE COOLER WED...ESPECIALLY NEAR LAKE SUPERIOR WHERE
LAKE BREEZE WILL BE MORE ACTIVE THAN TODAY. DWPTS MIGHT BE A LITTLE
LOWER...BUT CONDITIONS WILL STILL BE UNCOMFORTABLY HUMID.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 351 PM EDT TUE SEP 1 2015
AT 00Z THURSDAY A SHORTWAVE WILL BE SET UP ACROSS UPPER MI AND
WI...RIDING THE N EDGE OF THE LARGER 500MB RIDGE SET UP ACROSS MUCH
OF THE CENTRAL U.S.
AS A RESULT...WILL START OFF WITH SLIGHT CHANCE POPS SLOWLY EXITING
SE WEDNESDAY NIGHT...WITH MAINLY DRY WEATHER THEN FIGURED THURSDAY
THROUGH AT LEAST FRIDAY AS THE 500MB RIDGE BUILDS BACK ACROSS THE
UPPER GREAT LAKES. 80S STILL LOOK ON TRACK FOR TEMPS THROUGH
SATURDAY...IF NOT SUNDAY TOO. THERE WILL BE SLIGHT DIFFERENCES EACH
DAY...BUT MAINLY A BETTER PUSH OF AIR OFF LAKE MI WHERE THEY WILL BE
HELD IN THE 70S.
A LOW EJECTING OUT OF THE PACIFIC NW WILL SWING TO THE S CENTRAL
CANADA AND THE DAKOTAS BY 12Z MONDAY...WITH A BREAKDOWN OF THE UPPER
LEVEL RIDGE OVER THE UPPER GREAT LAKES. BEST CHANCE OF RAIN LOOKS TO
BE LATER SUNDAY NIGHT INTO MONDAY. THE LATEST ECMWF SHOWS ONLY
LIMITED PRECIP REMAINING AS THE SYSTEM MOVES E DURING THE DAY
MONDAY. LOOK FOR TEMPERATURES TO FALL BACK TO NEAR NORMAL FOR HIGHS
MONDAY...AND THEN QUITE A CHANGE FOR TUESDAY WITH HIGHS CURRENTLY
ONLY FCST TO BE IN THE MID TO UPPER 60S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 721 PM EDT TUE SEP 1 2015
VFR CONDITIONS WILL PREVAIL INTO THE EVENING HRS AT KIWD/KCMX/KSAW.
FOG WILL LIKELY BE AN ISSUE AGAIN TONIGHT WITH IFR/VLIFR CONDITIONS
POSSIBLE ESPECIALLY KCMX AND KSAW. IMPROVEMENT TO VFR WILL OCCUR
AROUND MID MORNING ON WED.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 438 PM EDT TUE SEP 1 2015
SUMMER PATTERN WILL DOMINATE THE UPPER GREAT LAKES THRU THE WEEK
WITH WINDS ON LAKE SUPERIOR UNDER 20KT. FOR MUCH OF THE TIME...
WINDS WILL BE UNDER 15KT. AT SOME POINT OVER THE WEEKEND...LIKELY
LATE IN THE WEEKEND...PRES GRADIENT WILL TIGHTEN AHEAD OF AN
APPROACHING COLD FRONT. THIS WILL LEAD TO AN UPTICK IN WINDS WITH A
BETTER POTENTIAL FOR GUSTS TO REACH THE 20-30KT RANGE. FINALLY...FOG
MAY BE AN ISSUE OVER AT LEAST PORTIONS OF THE LAKE FOR THE NEXT
SEVERAL DAYS UNDER WARM/HUMID AIR MASS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR LMZ248-250.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
426 PM EDT MON AUG 31 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 418 PM EDT MON AUG 31 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A PROMINENT MID/UPEPR LEVEL
RIDGE FROM NM INTO THE GREAT LAKES RESULSTING IN SW FLOW FROM THE
CNTRL ROCKIES INTO THE UPPER MS VALLEY. A WELL-DEFINED SHORTWAVE
TROUGH OVER SRN MANITOBA WAS LIFTING TO THE NE. AT THE SFC...SSW
FLOW PREAVILED ACROSS THE UPPER MS VALLEY AND WRN ALKES BETWEEN HIGH
PRES OVER THE CNTRL LAKES AND A COLD FRONT EXTENDING FROM THE SE
CORNER OF MANITOBA INTO ERN SD. MOST OF THE FOG FROM EARLIER TODAY
HAS BURNED OFF EXCEPT OVER THE FAR SE ALONG LAKE MI NEAR KISQ.
OTHERWISE...MOSTLY SUNNY SKIES PREVAILED WITH TEMPS AWAY FROM LAKE
MI INTO THE MID TO UPPER 80S.
TONIGHT...SEVERAL MODELS SUGGEST SOME SHRA/TSRA MAY DEVELOP FROM MN
INTO NW WI OR WRN LAKE SUPEROR AS AN AXIS OF HIGHER MOISTURE AND THE
TAIL OF THE MANITOBA SHRTWV SLIDES TO THE EAST. HOWEVER...THE AMOUNT
OF CAPPING AND ONLY WEAK MID LEVEL QVECTOR CONV...EXPECT ANY
COVERAGE TO BE MINIMAL AND REMAIN TO THE WEST OF THE CWA. ALTHOUGH
BNDRY LAYER WINDS WILL BE HIGHER THAN LAST NIGHT...EXPECT PATCHY/AREAS
TO REDEVELOP OVER MAINLY THE SE HALF.
TUE...PCPN CHANCES WILL INCREASE AS THE MOISTURE AXIS AND WEAK
TROUGH SAG INTO UPPER MICHIGAN. ALTHOUGH SOME PCPN MAY BE POSSIBLE
IN THE MORNING...EXPECT BETTER SHRA/TSRA CHANCES BY AFTERNOON WITH
INCREASED DAYTIME HEATING AND SUPPORT FROM DEVELOPING LAKE BREEZE
BOUNDARIES. TSRA WILL BE POSSIBLE WITH MLCAPE VALUES INTO THE 1K-2K
J/KG RANGE. HOWEVER WITH 0-6KM SHEAR VALUES ONLY AROUND 25-30 KNOTS
AND WITH WBZ HEGHTS NEAR 13K FT...SEVERE TS CHANCES WILL BE MINIMAL.
THE MAIN HAZARDS WILL BE BRIEF HEAVY RAIN AND GUSTY WINDS. EVEN WITH
INCREASED CLOUD COVER...TEMPS SHOULD AGAIN CLIMB INTO THE MID TO
UPPER 80S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 426 PM EDT MON AUG 31 2015
MORE 80S ARE ON THE WAY THROUGH AT LEAST SATURDAY. THE 500MB RIDGE
SET UP FROM W TX-LOWER MI...EXTENDING UP THROUGH HUDSON BAY WILL
FLATTEN OUT ONLY SLIGHTLY...BEFORE REBOUNDING OVER THE UPPER GREAT
LAKES WEDNESDAY NIGHT THROUGH AT LEAST SATURDAY.
WE WILL HAVE A LONG STRETCH OF TEMPERATURES AT OR ABOVE
80F...PROBABLY 8 DAYS IN TOTAL. IT WILL LIKELY END UP THE LONGEST
STRETCH IN 2 YEARS...AND TIED FOR THE LONGEST STRETCH IN 9 YEARS.
THE LAST TIME WE HAD MORE THAN 7 DAYS IN A ROW WAS IN 2006.
ALTHOUGH A NEARING SFC TROUGH TUESDAY NIGHT WILL KEEP LOW POPS OVER
MAINLY E LAKE SUPERIOR...IT WILL WILL HAVE TO OVERCOME PLENTY OF DRY
AIR. PW VALUES DO INCREASE TO 1.7 TO NEAR 2IN E.
ANY WIDESPREAD PRECIP WILL LIKELY HOLD OFF UNTIL SUNDAY OR EVEN
SUNDAY NIGHT UNTIL MONDAY. THE GFS IS A BIT SLOWER THAN THEN ECMWF.
THE APEX OF THE 500MB RIDGE WILL SHIFT W ACROSS THE LOWER GREAT
LAKES AND NEW ENGLAND STATES FOR THE LATTER HALF OF THE
WEEKEND...WITH SW FLOW MOVING INTO OUR AREA. TIMING OF THE NEXT
500MB LOW OR SIGNIFICANT WAVE EJECTING OUT OF THE W TROUGH IS STILL
UNCERTAIN. HOWEVER...INITIAL LOOKS SHOW THAT NEXT TUESDAY OR
WEDNESDAY COULD GIVE US A BETTER CHANCE OF SOME COOLER
AIR...ALTHOUGH IT MAY BE SHORT LIVED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 741 AM EDT MON AUG 31 2015
PATCHY GROUND FOG IS AFFECTING KSAW/KCMX AT THE START OF THE TAF
PERIOD...BUT STRONGER WINDS ALOFT AND DIURNAL HEATING SHOULD
QUICKLY DISSIPATE THE FOG THIS MORNING. OTHERWISE...EXPECT VFR
CONDITIONS TO PREVAIL AT THE SITES THROUGH MUCH OF THE REST OF THE
PERIOD. A WEAK TROUGH WILL NEAR THE WESTERN SITES LATE TONIGHT AND
COULD PRODUCE SOME SPRINKLES...WITH KSAW ONCE AGAIN SEEING THE
POTENTIAL FOR PATCHY GROUND FOG (ALTHOUGH WINDS ABOVE THE SURFACE
WILL BE A TOUCH STRONGER).
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 418 PM EDT MON AUG 31 2015
EXPECT SOUTH-SOUTHWESTERLY WINDS TO CONTINUE OVER LAKE SUPERIOR
THROUGH MUCH OF THE WEEK...AS THE AREA IS ON THE NORTHWESTERN EDGE
OF A HIGH PRESSURE RIDGE CENTERED OVER THE CENTRAL APPALACHIANS.
THERE WILL BE A BRIEF INCREASE IN THE SOUTHWESTERLY WINDS
TONIGHT...UP TO 20KTS...AS A LOW PRESSURE SYSTEM MOVES THROUGH NW
ONTARIO TO SOUTHERN HUDSON BAY BY TUE MORNING. AT THIS TIME...THE
MARINE LAYER SHOULD KEEP THE WINDS IN CHECK...BUT COULD SEE HIGHER
GUSTS TO 25 OR EVEN 30KTS AT A FEW OF THE HIGHER PLATFORMS TOWARDS
ISLE ROYALE. OTHERWISE...EXPECT WINDS TO BE BELOW 20KTS FOR THE REST
OF THE PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...SRF
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
421 PM EDT MON AUG 31 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 418 PM EDT MON AUG 31 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A PROMINENT MID/UPEPR LEVEL
RIDGE FROM NM INTO THE GREAT LAKES RESULSTING IN SW FLOW FROM THE
CNTRL ROCKIES INTO THE UPPER MS VALLEY. A WELL-DEFINED SHORTWAVE
TROUGH OVER SRN MANITOBA WAS LIFTING TO THE NE. AT THE SFC...SSW
FLOW PREAVILED ACROSS THE UPPER MS VALLEY AND WRN ALKES BETWEEN HIGH
PRES OVER THE CNTRL LAKES AND A COLD FRONT EXTENDING FROM THE SE
CORNER OF MANITOBA INTO ERN SD. MOST OF THE FOG FROM EARLIER TODAY
HAS BURNED OFF EXCEPT OVER THE FAR SE ALONG LAKE MI NEAR KISQ.
OTHERWISE...MOSTLY SUNNY SKIES PREVAILED WITH TEMPS AWAY FROM LAKE
MI INTO THE MID TO UPPER 80S.
TONIGHT...SEVERAL MODELS SUGGEST SOME SHRA/TSRA MAY DEVELOP FROM MN
INTO NW WI OR WRN LAKE SUPEROR AS AN AXIS OF HIGHER MOISTURE AND THE
TAIL OF THE MANITOBA SHRTWV SLIDES TO THE EAST. HOWEVER...THE AMOUNT
OF CAPPING AND ONLY WEAK MID LEVEL QVECTOR CONV...EXPECT ANY
COVERAGE TO BE MINIMAL AND REMAIN TO THE WEST OF THE CWA. ALTHOUGH
BNDRY LAYER WINDS WILL BE HIGHER THAN LAST NIGHT...EXPECT PATCHY/AREAS
TO REDEVELOP OVER MAINLY THE SE HALF.
TUE...PCPN CHANCES WILL INCREASE AS THE MOISTURE AXIS AND WEAK
TROUGH SAG INTO UPPER MICHIGAN. ALTHOUGH SOME PCPN MAY BE POSSIBLE
IN THE MORNING...EXPECT BETTER SHRA/TSRA CHANCES BY AFTERNOON WITH
INCREASED DAYTIME HEATING AND SUPPORT FROM DEVELOPING LAKE BREEZE
BOUNDARIES. TSRA WILL BE POSSIBLE WITH MLCAPE VALUES INTO THE 1K-2K
J/KG RANGE. HOWEVER WITH 0-6KM SHEAR VALUES ONLY AROUND 25-30 KNOTS
AND WITH WBZ HEGHTS NEAR 13K FT...SEVERE TS CHANCES WILL BE MINIMAL.
THE MAIN HAZARDS WILL BE BRIEF HEAVY RAIN AND GUSTY WINDS. EVEN WITH
INCREASED CLOUD COVER...TEMPS SHOULD AGAIN CLIMB INTO THE MID TO
UPPER 80S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 428 AM EDT MON AUG 31 2015
NO BIG CHANGES TO THE OVERALL IDEA OF LATE SUMMER RIDGING DOMINATING
INTO NEXT WEEKEND. TROUGHING ALOFT WITH MUCH COOLER CONDITIONS STILL
ON TRACK TO ARRIVE AROUND LABOR DAY.
RIDGE ALOFT FLATTENS OUT SLIGHTLY TUE INTO WED WHICH ALLOWS WEAK
SHORTWAVES TO CROSS THE REGION AND AT LEAST SOME CHANCES OF RAIN.
STRONGEST WAVE BY FAR STAYS OVER NORTHERN ONTARIO WITH ASSOCIATED
SFC LOW...BUT THERE IS STILL HINT FM MODELS THAT TAIL OF THAT
SHORTWAVE OR ADDITIONAL MINOR WAVES LIFTING IN FM THE
SOUTHWEST...AND ASSOCIATED SUBTLE H7-H5 Q-VECTOR CONVERGENCE WILL
COMBINE WITH WEAK SFC TROUGH AND LAKE BREEZES TO DEVELOP A FEW
SHRA/TSRA. WITH HEIGHTS LOWERING ALSO CANNOT DISCOUNT IDEA SHOWN BY
NAM/GEM-REGIONAL THAT ISOLD SHRA COULD WORK IN AS EARLY AS THE
MORNING AS WEAK SHORTWAVES SLIDING THROUGH COMBINE WITH MOISTURE
ADVECTION AT H85. GEM-REGIONAL SHOWS QPF OVER KEWEENAW 12Z-15Z WHICH
IS ALSO SUPPORTED BY LATEST NCAR ENSEMBLES. OVERALL THOUGH...LACKING
DEEPER MOISTURE AS SEEN IN FORECAST SOUNDINGS WILL BE LIMITING
FACTOR FOR MUCH PRECIP. TSRA CHANCES PROBABLY TOP OUT DURING PEAK
HEATING OF DAY...BUT WITH 1-6KM MUCAPE OVER 500J/KG POKING IN OVER
WESTERN CWA IN THE MORNING...CANNOT COMPLETELY RULE OUT. IF A TSRA
COULD FORM...ESPECIALLY DURING PEAK HEATING OF AFTN...COULD SEE AN
ISOLD STRONGER STORM WITH MLCAPES TO AROUND 1000J/KG AND DEEP LAYER
SHEAR 30+ KTS. SMALL DCAPES AND WBZERO HEIGHTS TO 12KFT WOULD SUPPORT
ONLY A MARGINAL HAIL RISK. LIGHTNING AND HEAVY DOWNPOURS WOULD BE
MAIN HAZARDS. STORM MOTION WOULD BE FM WEST TO EAST AT 25-30 KTS.
BASED ON H85 TEMPS AROUND 18C WILL GO FOR HIGHS IN THE MID 80S...DOWN
SOME FM THE LOW 90S FORECAST TODAY.
WEAKNESS IN RIDGE STILL THERE FOR WED AND WED NIGHT SO MAY SEE
ANOTHER OPPORTUNITY FOR SOME SHRA/TSRA. WEAK LARGE SCALE SUPPORT AND
MARGINAL MOISTURE WILL CONTINUE TO LIMIT COVERAGE. BEST CHANCE OF
SHRA/TSRA SHOULD BE DURING PEAK HEATING ON WED AFTN. THEN INTO WED
NIGHT...BASED ON ITS OWN FORECAST SOUDNINGS...LAST COUPLE RUNS OF
GFS SEEM TOO AMBITIOUS SHOWING WIDESPREAD LIGHT QPF IN ARC FM CNTRL
MANITOBA/NORTHWEST ONTARIO TO THE UPPER GREAT LAKES. SOUNDINGS SHOW
A LOT OF DRY AIR BLO H6 AND THE MID LEVEL RH SUGGESTS MAYBE BKN
CLOUDS BUT NOT A LOT OF PRECIP. WILL FOLLOW THE DRIER NAM/GEM-
NH/ECMWF WITH ONLY SCATTERED MID CLOUDS. HEAT CONTINUES WITH
READINGS ON WED REACHING BACK TOWARD 90 DEGREES OVER WEST AND MID-
UPR 80S ELSEWHERE AWAY FM LK MICHIGAN. DEVELOPING SSE WINDS WILL
KEEP IMMEDIATE LAKE SUPERIOR SHORE FM KEWEENAW TO BIG BAY/MARQUETTE
A SHADE COOLER.
SHORTWAVE WORKING ACROSS UPPER GREAT LAKES THURDAY APPEARS TO STAY
SOUTH OF UPR MICHIGAN AT LEAST RIGHT NOW. CHANCES OF SHRA/TSRA WILL
BE LOW...BUT WILL KEEP SLIGHT CHANCES DURING PEAK HEATING ON THU
AFTN. TEMPS ON THU MID 80S TO NEAR 90...SIMILAR TO READINGS ON WED
WITH MINIMAL CHANGE IN H85 TEMPS OF 18-20C. UPPER RIDGE BUILDS BACK
OVER GREAT LAKES ON FRIDAY SO ANY SHORTWAVES WORKING THROUGH BY THAT
TIME SHOULD BE WEAK. WITHOUT MUCH LARGE SCALE SUPPORT...SHRA/TSRA
SHOULD BE TIED TO EDGE OF STRONGEST INSTABILITY EXPANDING FM THE
PLAINS. REMNANTS OF THIS ACTIVITY MAY TRY TO MAKE IT OVER UPPER
GREAT LAKES LATER FRIDAY INTO SATURDAY. TIME FRAME SEEMS LIKE IT
WILL END UP MOSTLY DRY THOUGH. HIGH TEMPS SIMILAR TO WED AND THU.
GFS AND ECMWF/GEM-NH SHOW DIFFERENCES FOR THE UPCOMING WEEKEND.
MAIN ISSUE IS HOW QUICKLY COLD FRONT THAT USHERS IN MUCH COOLER
CONDITIONS WILL ARRIVE. AS THE FRONT DRAWS CLOSER MAY SEE BETTER
CHANCES OF SHRA/TSRA OVER AT LEAST WESTERN CWA ON SATURDAY. HEAT
CONTINUES WITH HIGHS AGAIN UPR 80S TO AROUND 90 DEGREES. GFS HAS
BACKED AWAY FM THE 22-24C H85 TEMPS IT SHOWED YDY...SO PROBABLY
LOOKING AT MAX TEMPS INTO THE LOWER 90S AT THE WARMEST. GFS MUCH
QUICKER SHOWING FRONT MOVING THROUGH ON SUNDAY WHILE ECMWF IS
STRONGER WITH UPPER RIDGE AND DOES NOT BRING THE FRONT THROUGH
UNTIL MONDAY. TYPICALLY THE STRONGER RIDGE WINS OUT. AT THIS POINT
WILL NOT STRAY FM MODEL CONSENSUS WHICH RESULTS IN LOW CHANCE POPS
FOR SUNDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 741 AM EDT MON AUG 31 2015
PATCHY GROUND FOG IS AFFECTING KSAW/KCMX AT THE START OF THE TAF
PERIOD...BUT STRONGER WINDS ALOFT AND DIURNAL HEATING SHOULD
QUICKLY DISSIPATE THE FOG THIS MORNING. OTHERWISE...EXPECT VFR
CONDITIONS TO PREVAIL AT THE SITES THROUGH MUCH OF THE REST OF THE
PERIOD. A WEAK TROUGH WILL NEAR THE WESTERN SITES LATE TONIGHT AND
COULD PRODUCE SOME SPRINKLES...WITH KSAW ONCE AGAIN SEEING THE
POTENTIAL FOR PATCHY GROUND FOG (ALTHOUGH WINDS ABOVE THE SURFACE
WILL BE A TOUCH STRONGER).
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 418 PM EDT MON AUG 31 2015
EXPECT SOUTH-SOUTHWESTERLY WINDS TO CONTINUE OVER LAKE SUPERIOR
THROUGH MUCH OF THE WEEK...AS THE AREA IS ON THE NORTHWESTERN EDGE
OF A HIGH PRESSURE RIDGE CENTERED OVER THE CENTRAL APPALACHIANS.
THERE WILL BE A BRIEF INCREASE IN THE SOUTHWESTERLY WINDS
TONIGHT...UP TO 20KTS...AS A LOW PRESSURE SYSTEM MOVES THROUGH NW
ONTARIO TO SOUTHERN HUDSON BAY BY TUE MORNING. AT THIS TIME...THE
MARINE LAYER SHOULD KEEP THE WINDS IN CHECK...BUT COULD SEE HIGHER
GUSTS TO 25 OR EVEN 30KTS AT A FEW OF THE HIGHER PLATFORMS TOWARDS
ISLE ROYALE. OTHERWISE...EXPECT WINDS TO BE BELOW 20KTS FOR THE REST
OF THE PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...SRF
MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
617 PM CDT TUE SEP 1 2015
.UPDATE...
ISSUED AT 616 PM CDT TUE SEP 1 2015
UPDATED TO INCLUDE 00Z AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 426 PM CDT TUE SEP 1 2015
A COMPACT...POTENT MID LEVEL DISTURBANCE OVER SERN SD/SWRN MN
WILL LIFT NORTHEAST ACROSS SRN/ERN MN TONIGHT AND ACROSS
NRN/CENTRAL WI WEDNESDAY. CONSIDERABLE CLOUDINESS HAS SHROUDED
MOST OF THE CWA THIS AFTERNOON...AND A FEW SHOWERS HAVE DEVELOPED
ON THE LEADING EDGE OF THE MID LEVEL VORT FROM WEST CENTRAL MN TO
SERN SD. ADDITIONAL SHOWERS AND STORMS WILL DEVELOP WITH THIS VORT
TONIGHT AND MOST HI-RES GUIDANCE SEEM TO HAVE A GENERAL CONSENSUS ON
THIS POTENTIAL. RAISED POPS INTO THE LIKELY CATEGORY ACROSS SRN MN
TO EAST CENTRAL MN AS THIS VORT TRACKS THROUGH WITH GOOD
FORCING...IN CONJUNCTION WITH A 30 KT LLJ BY 06Z POINTING INTO
SWRN MN. THEY MAY NEED TO BE RAISED TO CATEGORICAL IF AN
ORGANIZED COMPLEX CAN DEVELOP SIMILAR TO THAT SHOWN ON THE HRRR
AND 15Z HOPWRF MEMBERS LATER THIS EVENING.
DEW POINTS HAVE BEEN HIGHER THAN ANY GUIDANCE HAS INDICATED
TODAY...WITH LOW TO MID 70S ACROSS THE WHOLE CWA. A NOTED
EXCEPTION IS FOUND ACROSS NORTHERN MORRISON...DOUGLAS...AND TODD
COUNTIES WHERE A BOUNDARY EXISTS. NORTH OF THAT...DEW POINTS HAVE
BEEN IN THE 50S AND 60S. THESE HIGHER DEW POINTS HAVE CONTRIBUTED
TO A MODERATELY OR STRONGLY UNSTABLE AIRMASS WITH MLCAPE VALUES
EXCEEDING 3000 J/KG WHERE DEW POINTS ARE IN THE MID 70S FROM NEAR
WILLMAR TO THE TWIN CITIES METRO. THIS WILL ALSO AID IN
SHOWER/THUNDERSTORM DEVELOPMENT THIS EVENING.
WHAT EVER DOES DEVELOP TONIGHT WILL LIKELY BE IN A WEAKENING
PHASE WEDNESDAY MORNING WITH THE LOSS OF THE LLJ AND DIMINISHED
INSTABILITY. BEST PROBABILITY OF PRECIP WILL BE ON THE
SOUTHERN/EASTERN EDGE OF THE VORT ACROSS SERN MN/WRN WI.
REDEVELOPMENT COULD OCCUR AS INSTABILITY BUILDS AGAIN BY AFTERNOON
ACROSS ERN MN AND ESPECIALLY WI.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 426 PM CDT TUE SEP 1 2015
THERE MAY BE SOME LINGERING STORMS OVER WI WEDNESDAY EVENING UNTIL
THE VORT CAN FINALLY EXIT WELL TO THE EAST. MID LEVEL RIDGING WILL
BUILD BACK IN FOR LATE WEEK WITH HEIGHTS RISING TO AROUND 587 DM.
GFS IS MUCH MORE BULLISH WITH THE RIDGE AND IS SHOWING ITS WARM
BIAS ON 2M TEMPS AGAIN...WITH THE OTHER MODELS ADVERTISING A NOTED
WEAKNESS IN THE RIDGE OVER THE GREAT LAKES THANKS TO THE CURRENT
VORT THAT GETS CUT OFF. THE SOUTH/SOUTHEAST SURFACE FLOW FROM THIS
REGION COULD SAVE THE AREA FROM EXCEEDING 90 DEGREES A FEW DAYS
IN A ROW...THOUGH IT IS STILL EXPECTED TO BE VERY WARM AND HUMID.
HEAT INDICES MAY REACH THE MID 90S DEPENDING ON DEW POINTS WHICH
COULD BE A BIT LOW IN THE CURRENT FORECAST BASED ON WHAT HAS BEEN
OCCURRING TODAY. POPS REMAIN LOW THROUGH MOST OF FRIDAY AS THE
DIGGING TROUGH OVER THE WEST COAST SHOULD KEEP FAR ENOUGH WEST NOT
TO INFLUENCE THE LOCAL AREA MUCH UNTIL THEN. THERE COULD BE A FEW
WEAKER DISTURBANCES LIFTING NORTHEAST AROUND THE PERIPHERY OF THE
RIDGE FRIDAY/SATURDAY WHICH MAY BRING SOME CHANCES OF STORMS
ACROSS MAINLY WESTERN AND NORTHERN MINNESOTA.
THE TROUGH WILL BEGIN LIFTING NORTHEAST BY EARLY IN THE WEEKEND.
HEIGHTS WILL FALL DURING THIS TIME WITH THE POTENTIAL FOR QUITE A
POTENT MID LEVEL SYSTEM PUSHING NORTHEAST ACROSS THE NORTHERN
PLAINS SUNDAY. WINDS WILL TURN SOUTH/SOUTHWEST AND THERMAL RIDGING
WILL ADVANCE EASTWARD TO MN FROM THE DAKOTAS. SUNDAY WILL BRING US
OUR BEST SHOT AT 90 JUST AHEAD OF THE APPROACHING COLD FRONT.
SHOWERS AND THUNDERSTORMS WILL DEVELOP ALONG THE FRONT LATE
SUNDAY/SUNDAY EVENING AND SHOULD BECOME WIDESPREAD ALONG IT THANKS
TO GOOD FORCING AND A VERY MOIST ATMOSPHERE. 850 MB DEW POINTS OF
+16 TO +19C AND PWATS OF 2 INCHES WILL BRING POTENTIAL FOR LOCALLY
HEAVY RAINFALL.
COOLER AND DRIER AIR WILL FOLLOW THE FRONT FOR EARLY NEXT WEEK.
REMOVED ANY POPS DURING THIS PERIOD WITH SURFACE HIGH PRESSURE
BUILDING IN.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 616 PM CDT TUE SEP 1 2015
SOME WEAK ELEVATED CONVECTION CAN CURRENTLY BE SEEN ACROSS THE
WESTERN PORTION OF THE AREA... AND COULD CAUSE SOME BRIEF ISSUES
AT KSTC OR KRWF THIS EVENING. OTHERWISE... MAIN CONCERN IS WITH
THE POSSIBILITY OF MORE WIDESPREAD SHRA/TSRA LATER TONIGHT AS A
BETTER UPPER WAVE LIFTS NORTHEAST INTO THE AREA AND IS ABLE TO
WORK WITH INSTABILITY AND MOISTURE CURRENTLY IN PLACE ACROSS THE
AREA. THE HRRR AND HOPWRF HAVE TRENDED TOWARD SHOWING A BIT MORE
IN THE WAY OF PCPN WITH THIS FEATURE OVERNIGHT INTO WEDNESDAY
MORNING... SO INCLUDED A BIT MORE IN THE WAY OF TEMPOS WITH THE
00Z TAFS TO ACCOUNT FOR THAT POSSIBILITY. OTHERWISE... VFR
CONDITIONS SHOULD PREDOMINATE. THERE IS THE POSSIBILITY OF SOME
MVFR FOG AT THE TYPICALLY PRONE AREAS... BUT DIDN/T INCLUDE IT AT
THIS POINT GIVEN EXPECTATIONS FOR QUITE A BIT OF CLOUD COVER
OVERNIGHT.
KMSP...HAVE MODERATE CONFIDENCE IN OVERALL FORECAST... WITH MAIN
UNCERTAINTY BEING THE CONVECTIVE POTENTIAL LATER TONIGHT. COULD
ALSO SEE SOME SCATTERED ACTIVITY LATER IN THE DAY ON WEDNESDAY...
AND INCLUDED PROB30 FOR THAT POSSIBILITY.
/OUTLOOK FOR KMSP/
WEDNESDAY OVERNIGHT...VFR. SOUTH WIND AROUND 5 KT.
THURSDAY...VFR. SOUTH TO SOUTHWEST WIND 5 TO 10 KT.
THURSDAY NIGHT...VFR. SOUTH WIND 5 TO 10 KT.
FRIDAY...VFR. SOUTH WIND 10 TO 20 KT.
FRIDAY NIGHT AND SATURDAY...MVFR POSSIBLE WITH A CHANCE OF
SHRA/TSRA. SOUTH WIND 10 TO 20 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
UPDATE...
SHORT TERM...BORGHOFF
LONG TERM...BORGHOFF
AVIATION...
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1220 PM CDT MON AUG 31 2015
.UPDATE...
ISSUED AT 1203 PM CDT MON AUG 31 2015
THE FOG HAS DISSIPATED EXCEPT ALONG THE NORTH SHORE FROM TACONITE
HARBOR TO GRAND PORTAGE. THE STRATUS IS HANGING ON IN NW WI...BUT
SOME IMPROVEMENT IS OCCURRING. HAZY SUNSHINE ELSEWHERE DUE TO
SMOKE FROM WESTERN U.S. WILDFIRES. COLD FRONT IN NW MN HAS MADE
LITTLE PROGRESS EWD...ALTHOUGH SOME CLOUDS ARE MOVING TOWARD
KOOCHICHING COUNTY. HAVE ADJUSTED FOR THESE TRENDS.
UPDATE ISSUED AT 915 AM CDT MON AUG 31 2015
A COLD FRONT WAS DRAPED OVER EASTERN ND AND THE EXTREME CORNER OF NW
MN AT 14Z. THUNDERSTORMS WERE OCCURRING BEHIND THE FRONT IN NE ND
AND LIFTING NEWD INTO CANADA. SOUTHERLY FLOW OVER THE FORECAST
AREA HAS LED TO A STRATUS DECK OVER NW WI AND ADJACENT MN AND
ALONG THE NORTH SHORE OF LAKE SUPERIOR WITH SOME FOG THAT WAS
SLOWLY LIFTING. EXPECT THE STRATUS AND FOG TO CONTINUE TO ERODE
THIS MORNING AND HAVE ADJUSTED FOR THIS TREND. WITH THE STORMS
MOVING INTO CANADA AND LATEST HRRR INDICATING NO STORMS INTO THE
REGION THROUGH THE AFTERNOON FOR THE LAST FEW RUNS. HAVE REMOVED
THE MENTION OF STORMS TODAY.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 240 AM CDT MON AUG 31 2015
AN UPPER RIDGE WILL MOVE EAST OF THE REGION TODAY WITH SOUTHERLY
SURFACE FLOW KEEPING HIGHER DEWPOINTS IN PLACE. A COLD FRONT WILL
MOVE INTO FAR WESTERN MINNESOTA BY LATE AFTERNOON/EARLY EVENING
AND PROGRESS INTO NORTHEAST MINNESOTA TONIGHT BEFORE WEAKENING
TUESDAY.
STRATUS AND SOME PATCHY FOG HAVE ONCE AGAIN FORMED ACROSS
NORTHERN WISCONSIN AND PORTIONS OF NORTHEAST MINNESOTA THIS
MORNING. THE STRATUS/FOG SHOULD BURN OFF THIS MORNING AND THE RAP
SEEMS TO BE HANDLING THIS DECENTLY. CLOUDS WILL DIMINISH THROUGH
THE MORNING...THEN INCREASE AGAIN OVER WESTERN AREAS THIS
AFTERNOON AHEAD OF THE COLD FRONT. WE KEPT A MENTION OF
SHOWERS/STORMS IN THE WEST LATE TODAY...THEN PROGRESS THE CHANCE
EAST TONIGHT. THE NAM/GFS/ECMWF ALONG WITH THE HIGHER RESOLUTION
CAMS SUGGEST COVERAGE WILL BE LIMITED SO WE ONLY HAVE LOW POPS AT
THIS TIME. WE EXPECT HIGHS ABOVE NORMAL AGAIN TODAY...BUT DID
LOWER A BIT IN SPOTS DUE TO THE STRATUS IN PLACE EARLY. WE HAVE
HIGHS FROM AROUND 80 TO 85 FOR MOST AREAS.
THE FRONT WILL WEAKEN TUESDAY...BUT MAY STILL BE STRONG ENOUGH TO
FORCE A FEW SHOWERS/STORMS OVER PORTIONS OF NORTHWEST WISCONSIN
WHERE WE KEPT SOME POPS INTO THE AFTERNOON AND OVER FAR EASTERN
MINNESOTA IN THE MORNING. THERE MAY AGAIN BE SOME STRATUS/FOG THAT
FORM TONIGHT. HIGHS TUESDAY WILL AGAIN BE FROM 80 TO 85 FOR MOST
AREAS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 240 AM CDT MON AUG 31 2015
WARM AND HUMID THROUGH THE REST OF THE WORK WEEK WITH OCCASIONAL
CHANCES FOR STORMS. THIS WEEKEND A STRONGER UPPER-LEVEL SYSTEM
COMBINED WITH A COLD FRONT MOVING IN FROM THE WEST WILL LEAD TO
BETTER CHANCES FOR WIDESPREAD SHOWERS AND STORMS OVER THE
WEEKEND...WITH MORE SEASONABLE TEMPERATURES BEHIND THE FRONT.
WED/THURS/FRI...FEELING LIKE MID-SUMMER WITH TEMPERATURES ABOVE
NORMAL...DEW POINTS IN THE MID 60S TO NEAR 70...AND CHANCES FOR
STORMS INCREASING TOWARDS THE WEEKEND. THIS PATTERN WILL BE DUE TO A
LONGWAVE TROUGH DEVELOPING IN THE WEST AND A WEAK RIDGE OVER THE
EASTERN THIRD OF THE COUNTRY...A PATTERN WHICH GENERALLY PERSISTS
MID TO LATE WEEK. WITH A WARM FRONT LIFTING NORTH WEDNESDAY WINDS
WILL BE BREEZY WEDNESDAY AND WINDY THURSDAY...GUSTS UP TO 30 MPH
POSSIBLE THURSDAY. WHILE THERE WILL BE A SLIGHT CHANCE FOR ISOLATED
STORMS WED AND THURS...THE BETTER CHANCES FOR STORMS COME FRIDAY
WHEN A MID-LEVEL SHORTWAVE TROUGH LIFTS THROUGH THE CENTRAL/NORTHERN
PLAINS INTO THE UPPER MIDWEST. PLENTY OF ELEVATED INSTABILITY AND
INCREASING UPPER LEVEL WINDS COULD SUSTAIN A FEW STRONG STORMS...BUT
IN GENERAL DO NOT EXPECT SEVERE THUNDERSTORMS. HIGHS IN THE LOW 80S.
SAT/SUN...A MUCH MORE ACTIVE PERIOD WITH A COLD FRONT EVENTUALLY
SWEEPING ACROSS THE UPPER MIDWEST...WITH MUCH COOLER TEMPERATURES
BEHIND THE FRONT ON TAP FOR NEXT WEEK. GFS IS A VERY WET OUTLIER
WITH FRONTAL PASSAGE QUICKER THAN OTHER GUIDANCE...WITH THE GEFS
ENSEMBLE MEMBERS DEPICTING A WIDE RANGE OF TIMING POSSIBILITIES.
THERE IS POTENTIAL FOR SOME STRONG TO SEVERE STORMS GIVEN STRONGER
WINDS ALOFT...BUT WILL CONTINUE TO HOLD OFF MENTIONING THIS
POSSIBILITY IN THE HWO DUE TO LOW CONFIDENCE WITH REGARDS TO IF THE
RIGHT CONDITIONS WILL DEVELOP. HIGH FREEZING LEVELS /12-14 KFT/ MAY
LIMIT POTENTIAL FOR LARGE HAIL...AND FAIRLY SATURATED MODEL
SOUNDINGS INDICATE MORE OF A HEAVY RAIN THREAT. GFS DEPICTS A SWATH
OF 2+ INCH RAINFALL OVER NORTHEAST MINNESOTA FOR SATURDAY AFTERNOON
WHICH SEEMS LIKE AN OUTLIER COMPARED TO THE GEFS ENSEMBLE MEAN OF 3-
4 TENTHS OF AN INCH. GEFS NARR-REFORECAST-CALIBRATED PRECIP
PROBABILITIES FROM ESRL/PSD...A METHOD OF TRYING TO CALIBRATE THE
GEFS FORECASTS TO PAST EVENTS TO PRODUCE A MORE RELIABLE FORECAST
THAN THE RAW GEFS PROBABILITIES...INDICATE ONLY A 10-20 PERCENT
CHANCE FOR 1"+ PRECIP OVER ANY 12-HOUR PERIOD THIS WEEKEND...SO
THERE IS LITTLE SUPPORT FOR THE DETERMINISTIC GFS FROM ITS ENSEMBLE
AND THEREFORE AM TREATING IT MORE AS AN INTERESTING OUTLIER THAN A
LIKELY SCENARIO. TEMPS WILL BE COOLER BEHIND THE FRONT...WHICH WILL
PROBABLY BE ON SUNDAY GIVEN THE ECMWF SLOWER TIMING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1220 PM CDT MON AUG 31 2015
VFR CONDITIONS WILL CONTINUE THROUGH TODAY WITH GUSTY S/SW WINDS
15 TO 25 KTS. A WEAK COLD FRONT WILL SLIDE ACROSS THE REGION THIS
EVENING AND MAINLY ACT TO INCREASE CLOUD COVER...BUT COULD ALSO
INTERACT WITH A WEAKLY UNSTABLE AIR MASS TO TRIGGER A FEW SHOWERS
AND STORMS. PRECIP/STORM PROBABILITIES ARE LOW...BUT NOT LOW
ENOUGH TO NOT MENTION IN THE TAF WITH A VCTS/SH. FRONT CLEARS THE
AREA LATE TONIGHT AND ALLOWS PATCHY FOG TO DEVELOP TUE MORNING.
COULD SEE IFR/MVFR VSBYS/CIGS AT TIMES...BUT NOTHING TOO
WIDESPREAD. VFR CONDITIONS RETURN BY MID MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 81 65 84 63 / 0 30 20 10
INL 85 54 82 56 / 10 30 10 30
BRD 83 63 85 66 / 0 20 10 10
HYR 81 66 84 63 / 0 20 20 10
ASX 83 65 82 61 / 0 20 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SHORT TERM...MELDE
LONG TERM...JJM
AVIATION...TENTINGER
AREA FORECAST DISCUSSION
NWS DULUTH MN
1203 PM CDT MON AUG 31 2015
.UPDATE...
ISSUED AT 1203 PM CDT MON AUG 31 2015
THE FOG HAS DISSIPATED EXCEPT ALONG THE NORTH SHORE FROM TACONITE
HARBOR TO GRAND PORTAGE. THE STRATUS IS HANGING ON IN NW WI...BUT
SOME IMPROVEMENT IS OCCURRING. HAZY SUNSHINE ELSEWHERE DUE TO
SMOKE FROM WESTERN U.S. WILDFIRES. COLD FRONT IN NW MN HAS MADE
LITTLE PROGRESS EWD...ALTHOUGH SOME CLOUDS ARE MOVING TOWARD
KOOCHICHING COUNTY. HAVE ADJUSTED FOR THESE TRENDS.
UPDATE ISSUED AT 915 AM CDT MON AUG 31 2015
A COLD FRONT WAS DRAPED OVER EASTERN ND AND THE EXTREME CORNER OF NW
MN AT 14Z. THUNDERSTORMS WERE OCCURRING BEHIND THE FRONT IN NE ND
AND LIFTING NEWD INTO CANADA. SOUTHERLY FLOW OVER THE FORECAST
AREA HAS LED TO A STRATUS DECK OVER NW WI AND ADJACENT MN AND
ALONG THE NORTH SHORE OF LAKE SUPERIOR WITH SOME FOG THAT WAS
SLOWLY LIFTING. EXPECT THE STRATUS AND FOG TO CONTINUE TO ERODE
THIS MORNING AND HAVE ADJUSTED FOR THIS TREND. WITH THE STORMS
MOVING INTO CANADA AND LATEST HRRR INDICATING NO STORMS INTO THE
REGION THROUGH THE AFTERNOON FOR THE LAST FEW RUNS. HAVE REMOVED
THE MENTION OF STORMS TODAY.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 240 AM CDT MON AUG 31 2015
AN UPPER RIDGE WILL MOVE EAST OF THE REGION TODAY WITH SOUTHERLY
SURFACE FLOW KEEPING HIGHER DEWPOINTS IN PLACE. A COLD FRONT WILL
MOVE INTO FAR WESTERN MINNESOTA BY LATE AFTERNOON/EARLY EVENING
AND PROGRESS INTO NORTHEAST MINNESOTA TONIGHT BEFORE WEAKENING
TUESDAY.
STRATUS AND SOME PATCHY FOG HAVE ONCE AGAIN FORMED ACROSS
NORTHERN WISCONSIN AND PORTIONS OF NORTHEAST MINNESOTA THIS
MORNING. THE STRATUS/FOG SHOULD BURN OFF THIS MORNING AND THE RAP
SEEMS TO BE HANDLING THIS DECENTLY. CLOUDS WILL DIMINISH THROUGH
THE MORNING...THEN INCREASE AGAIN OVER WESTERN AREAS THIS
AFTERNOON AHEAD OF THE COLD FRONT. WE KEPT A MENTION OF
SHOWERS/STORMS IN THE WEST LATE TODAY...THEN PROGRESS THE CHANCE
EAST TONIGHT. THE NAM/GFS/ECMWF ALONG WITH THE HIGHER RESOLUTION
CAMS SUGGEST COVERAGE WILL BE LIMITED SO WE ONLY HAVE LOW POPS AT
THIS TIME. WE EXPECT HIGHS ABOVE NORMAL AGAIN TODAY...BUT DID
LOWER A BIT IN SPOTS DUE TO THE STRATUS IN PLACE EARLY. WE HAVE
HIGHS FROM AROUND 80 TO 85 FOR MOST AREAS.
THE FRONT WILL WEAKEN TUESDAY...BUT MAY STILL BE STRONG ENOUGH TO
FORCE A FEW SHOWERS/STORMS OVER PORTIONS OF NORTHWEST WISCONSIN
WHERE WE KEPT SOME POPS INTO THE AFTERNOON AND OVER FAR EASTERN
MINNESOTA IN THE MORNING. THERE MAY AGAIN BE SOME STRATUS/FOG THAT
FORM TONIGHT. HIGHS TUESDAY WILL AGAIN BE FROM 80 TO 85 FOR MOST
AREAS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 240 AM CDT MON AUG 31 2015
WARM AND HUMID THROUGH THE REST OF THE WORK WEEK WITH OCCASIONAL
CHANCES FOR STORMS. THIS WEEKEND A STRONGER UPPER-LEVEL SYSTEM
COMBINED WITH A COLD FRONT MOVING IN FROM THE WEST WILL LEAD TO
BETTER CHANCES FOR WIDESPREAD SHOWERS AND STORMS OVER THE
WEEKEND...WITH MORE SEASONABLE TEMPERATURES BEHIND THE FRONT.
WED/THURS/FRI...FEELING LIKE MID-SUMMER WITH TEMPERATURES ABOVE
NORMAL...DEW POINTS IN THE MID 60S TO NEAR 70...AND CHANCES FOR
STORMS INCREASING TOWARDS THE WEEKEND. THIS PATTERN WILL BE DUE TO A
LONGWAVE TROUGH DEVELOPING IN THE WEST AND A WEAK RIDGE OVER THE
EASTERN THIRD OF THE COUNTRY...A PATTERN WHICH GENERALLY PERSISTS
MID TO LATE WEEK. WITH A WARM FRONT LIFTING NORTH WEDNESDAY WINDS
WILL BE BREEZY WEDNESDAY AND WINDY THURSDAY...GUSTS UP TO 30 MPH
POSSIBLE THURSDAY. WHILE THERE WILL BE A SLIGHT CHANCE FOR ISOLATED
STORMS WED AND THURS...THE BETTER CHANCES FOR STORMS COME FRIDAY
WHEN A MID-LEVEL SHORTWAVE TROUGH LIFTS THROUGH THE CENTRAL/NORTHERN
PLAINS INTO THE UPPER MIDWEST. PLENTY OF ELEVATED INSTABILITY AND
INCREASING UPPER LEVEL WINDS COULD SUSTAIN A FEW STRONG STORMS...BUT
IN GENERAL DO NOT EXPECT SEVERE THUNDERSTORMS. HIGHS IN THE LOW 80S.
SAT/SUN...A MUCH MORE ACTIVE PERIOD WITH A COLD FRONT EVENTUALLY
SWEEPING ACROSS THE UPPER MIDWEST...WITH MUCH COOLER TEMPERATURES
BEHIND THE FRONT ON TAP FOR NEXT WEEK. GFS IS A VERY WET OUTLIER
WITH FRONTAL PASSAGE QUICKER THAN OTHER GUIDANCE...WITH THE GEFS
ENSEMBLE MEMBERS DEPICTING A WIDE RANGE OF TIMING POSSIBILITIES.
THERE IS POTENTIAL FOR SOME STRONG TO SEVERE STORMS GIVEN STRONGER
WINDS ALOFT...BUT WILL CONTINUE TO HOLD OFF MENTIONING THIS
POSSIBILITY IN THE HWO DUE TO LOW CONFIDENCE WITH REGARDS TO IF THE
RIGHT CONDITIONS WILL DEVELOP. HIGH FREEZING LEVELS /12-14 KFT/ MAY
LIMIT POTENTIAL FOR LARGE HAIL...AND FAIRLY SATURATED MODEL
SOUNDINGS INDICATE MORE OF A HEAVY RAIN THREAT. GFS DEPICTS A SWATH
OF 2+ INCH RAINFALL OVER NORTHEAST MINNESOTA FOR SATURDAY AFTERNOON
WHICH SEEMS LIKE AN OUTLIER COMPARED TO THE GEFS ENSEMBLE MEAN OF 3-
4 TENTHS OF AN INCH. GEFS NARR-REFORECAST-CALIBRATED PRECIP
PROBABILITIES FROM ESRL/PSD...A METHOD OF TRYING TO CALIBRATE THE
GEFS FORECASTS TO PAST EVENTS TO PRODUCE A MORE RELIABLE FORECAST
THAN THE RAW GEFS PROBABILITIES...INDICATE ONLY A 10-20 PERCENT
CHANCE FOR 1"+ PRECIP OVER ANY 12-HOUR PERIOD THIS WEEKEND...SO
THERE IS LITTLE SUPPORT FOR THE DETERMINISTIC GFS FROM ITS ENSEMBLE
AND THEREFORE AM TREATING IT MORE AS AN INTERESTING OUTLIER THAN A
LIKELY SCENARIO. TEMPS WILL BE COOLER BEHIND THE FRONT...WHICH WILL
PROBABLY BE ON SUNDAY GIVEN THE ECMWF SLOWER TIMING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 653 AM CDT MON AUG 31 2015
ANOTHER MORNING WITH LIFR/IFR CEILINGS ACROSS THE
REGION...CONDITIONS WHICH SHOULD IMPROVE BY MID-MORNING. THIS
AFTERNOON WILL BE VFR WITH BREEZY WINDS OUT OF THE SOUTH...WINDS
STRONGEST AT BRD WHERE PEAK GUSTS TO AROUND 30 MPH ARE POSSIBLE.
THIS EVENING A WEAK FRONT WILL MOVE EAST ACROSS NORTHEAST
MINNESOTA WITH THE POTENTIAL FOR ISOLATED SHOWER/STORMS. CHANCES
ARE LOW...AND ONLY FELT CONFIDENT ENOUGH AT HIB TO INTRODUCE A
VCTS GROUP FOR THE EARLY EVENING. TONIGHT ANOTHER ROUND OF AT
LEAST MVFR VISIBILITY/CEILINGS ARE POSSIBLE AT DLH/HIB/HYR...BUT
THIS WILL BE DEPENDENT ON IF PRECIPITATION DEVELOPS AND HOW
WIDESPREAD IT BECOMES. INCLUDING A BEST GUESS IN THE TAFS ASSUMING
CONVECTION WILL BE ISOLATED IN NATURE AT BEST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 81 65 84 63 / 0 30 20 10
INL 85 54 82 56 / 10 30 10 30
BRD 83 63 85 66 / 0 20 10 10
HYR 81 66 84 63 / 0 20 20 10
ASX 83 65 82 61 / 0 20 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SHORT TERM...MELDE
LONG TERM...JJM
AVIATION...JJM
AREA FORECAST DISCUSSION
NWS DULUTH MN
915 AM CDT MON AUG 31 2015
.UPDATE...
ISSUED AT 915 AM CDT MON AUG 31 2015
A COLD FRONT WAS DRAPED OVER EASTERN ND AND THE EXTREME CORNER OF NW
MN AT 14Z. THUNDERSTORMS WERE OCCURRING BEHIND THE FRONT IN NE ND
AND LIFTING NEWD INTO CANADA. SOUTHERLY FLOW OVER THE FORECAST
AREA HAS LED TO A STRATUS DECK OVER NW WI AND ADJACENT MN AND
ALONG THE NORTH SHORE OF LAKE SUPERIOR WITH SOME FOG THAT WAS
SLOWLY LIFTING. EXPECT THE STRATUS AND FOG TO CONTINUE TO ERODE
THIS MORNING AND HAVE ADJUSTED FOR THIS TREND. WITH THE STORMS
MOVING INTO CANADA AND LATEST HRRR INDICATING NO STORMS INTO THE
REGION THROUGH THE AFTERNOON FOR THE LAST FEW RUNS. HAVE REMOVED
THE MENTION OF STORMS TODAY.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 240 AM CDT MON AUG 31 2015
AN UPPER RIDGE WILL MOVE EAST OF THE REGION TODAY WITH SOUTHERLY
SURFACE FLOW KEEPING HIGHER DEWPOINTS IN PLACE. A COLD FRONT WILL
MOVE INTO FAR WESTERN MINNESOTA BY LATE AFTERNOON/EARLY EVENING
AND PROGRESS INTO NORTHEAST MINNESOTA TONIGHT BEFORE WEAKENING
TUESDAY.
STRATUS AND SOME PATCHY FOG HAVE ONCE AGAIN FORMED ACROSS
NORTHERN WISCONSIN AND PORTIONS OF NORTHEAST MINNESOTA THIS
MORNING. THE STRATUS/FOG SHOULD BURN OFF THIS MORNING AND THE RAP
SEEMS TO BE HANDLING THIS DECENTLY. CLOUDS WILL DIMINISH THROUGH
THE MORNING...THEN INCREASE AGAIN OVER WESTERN AREAS THIS
AFTERNOON AHEAD OF THE COLD FRONT. WE KEPT A MENTION OF
SHOWERS/STORMS IN THE WEST LATE TODAY...THEN PROGRESS THE CHANCE
EAST TONIGHT. THE NAM/GFS/ECMWF ALONG WITH THE HIGHER RESOLUTION
CAMS SUGGEST COVERAGE WILL BE LIMITED SO WE ONLY HAVE LOW POPS AT
THIS TIME. WE EXPECT HIGHS ABOVE NORMAL AGAIN TODAY...BUT DID
LOWER A BIT IN SPOTS DUE TO THE STRATUS IN PLACE EARLY. WE HAVE
HIGHS FROM AROUND 80 TO 85 FOR MOST AREAS.
THE FRONT WILL WEAKEN TUESDAY...BUT MAY STILL BE STRONG ENOUGH TO
FORCE A FEW SHOWERS/STORMS OVER PORTIONS OF NORTHWEST WISCONSIN
WHERE WE KEPT SOME POPS INTO THE AFTERNOON AND OVER FAR EASTERN
MINNESOTA IN THE MORNING. THERE MAY AGAIN BE SOME STRATUS/FOG THAT
FORM TONIGHT. HIGHS TUESDAY WILL AGAIN BE FROM 80 TO 85 FOR MOST
AREAS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 240 AM CDT MON AUG 31 2015
WARM AND HUMID THROUGH THE REST OF THE WORK WEEK WITH OCCASIONAL
CHANCES FOR STORMS. THIS WEEKEND A STRONGER UPPER-LEVEL SYSTEM
COMBINED WITH A COLD FRONT MOVING IN FROM THE WEST WILL LEAD TO
BETTER CHANCES FOR WIDESPREAD SHOWERS AND STORMS OVER THE
WEEKEND...WITH MORE SEASONABLE TEMPERATURES BEHIND THE FRONT.
WED/THURS/FRI...FEELING LIKE MID-SUMMER WITH TEMPERATURES ABOVE
NORMAL...DEW POINTS IN THE MID 60S TO NEAR 70...AND CHANCES FOR
STORMS INCREASING TOWARDS THE WEEKEND. THIS PATTERN WILL BE DUE TO A
LONGWAVE TROUGH DEVELOPING IN THE WEST AND A WEAK RIDGE OVER THE
EASTERN THIRD OF THE COUNTRY...A PATTERN WHICH GENERALLY PERSISTS
MID TO LATE WEEK. WITH A WARM FRONT LIFTING NORTH WEDNESDAY WINDS
WILL BE BREEZY WEDNESDAY AND WINDY THURSDAY...GUSTS UP TO 30 MPH
POSSIBLE THURSDAY. WHILE THERE WILL BE A SLIGHT CHANCE FOR ISOLATED
STORMS WED AND THURS...THE BETTER CHANCES FOR STORMS COME FRIDAY
WHEN A MID-LEVEL SHORTWAVE TROUGH LIFTS THROUGH THE CENTRAL/NORTHERN
PLAINS INTO THE UPPER MIDWEST. PLENTY OF ELEVATED INSTABILITY AND
INCREASING UPPER LEVEL WINDS COULD SUSTAIN A FEW STRONG STORMS...BUT
IN GENERAL DO NOT EXPECT SEVERE THUNDERSTORMS. HIGHS IN THE LOW 80S.
SAT/SUN...A MUCH MORE ACTIVE PERIOD WITH A COLD FRONT EVENTUALLY
SWEEPING ACROSS THE UPPER MIDWEST...WITH MUCH COOLER TEMPERATURES
BEHIND THE FRONT ON TAP FOR NEXT WEEK. GFS IS A VERY WET OUTLIER
WITH FRONTAL PASSAGE QUICKER THAN OTHER GUIDANCE...WITH THE GEFS
ENSEMBLE MEMBERS DEPICTING A WIDE RANGE OF TIMING POSSIBILITIES.
THERE IS POTENTIAL FOR SOME STRONG TO SEVERE STORMS GIVEN STRONGER
WINDS ALOFT...BUT WILL CONTINUE TO HOLD OFF MENTIONING THIS
POSSIBILITY IN THE HWO DUE TO LOW CONFIDENCE WITH REGARDS TO IF THE
RIGHT CONDITIONS WILL DEVELOP. HIGH FREEZING LEVELS /12-14 KFT/ MAY
LIMIT POTENTIAL FOR LARGE HAIL...AND FAIRLY SATURATED MODEL
SOUNDINGS INDICATE MORE OF A HEAVY RAIN THREAT. GFS DEPICTS A SWATH
OF 2+ INCH RAINFALL OVER NORTHEAST MINNESOTA FOR SATURDAY AFTERNOON
WHICH SEEMS LIKE AN OUTLIER COMPARED TO THE GEFS ENSEMBLE MEAN OF 3-
4 TENTHS OF AN INCH. GEFS NARR-REFORECAST-CALIBRATED PRECIP
PROBABILITIES FROM ESRL/PSD...A METHOD OF TRYING TO CALIBRATE THE
GEFS FORECASTS TO PAST EVENTS TO PRODUCE A MORE RELIABLE FORECAST
THAN THE RAW GEFS PROBABILITIES...INDICATE ONLY A 10-20 PERCENT
CHANCE FOR 1"+ PRECIP OVER ANY 12-HOUR PERIOD THIS WEEKEND...SO
THERE IS LITTLE SUPPORT FOR THE DETERMINISTIC GFS FROM ITS ENSEMBLE
AND THEREFORE AM TREATING IT MORE AS AN INTERESTING OUTLIER THAN A
LIKELY SCENARIO. TEMPS WILL BE COOLER BEHIND THE FRONT...WHICH WILL
PROBABLY BE ON SUNDAY GIVEN THE ECMWF SLOWER TIMING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 653 AM CDT MON AUG 31 2015
ANOTHER MORNING WITH LIFR/IFR CEILINGS ACROSS THE
REGION...CONDITIONS WHICH SHOULD IMPROVE BY MID-MORNING. THIS
AFTERNOON WILL BE VFR WITH BREEZY WINDS OUT OF THE SOUTH...WINDS
STRONGEST AT BRD WHERE PEAK GUSTS TO AROUND 30 MPH ARE POSSIBLE.
THIS EVENING A WEAK FRONT WILL MOVE EAST ACROSS NORTHEAST
MINNESOTA WITH THE POTENTIAL FOR ISOLATED SHOWER/STORMS. CHANCES
ARE LOW...AND ONLY FELT CONFIDENT ENOUGH AT HIB TO INTRODUCE A
VCTS GROUP FOR THE EARLY EVENING. TONIGHT ANOTHER ROUND OF AT
LEAST MVFR VISIBILITY/CEILINGS ARE POSSIBLE AT DLH/HIB/HYR...BUT
THIS WILL BE DEPENDENT ON IF PRECIPITATION DEVELOPS AND HOW
WIDESPREAD IT BECOMES. INCLUDING A BEST GUESS IN THE TAFS ASSUMING
CONVECTION WILL BE ISOLATED IN NATURE AT BEST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 81 65 84 63 / 0 30 20 10
INL 85 54 82 56 / 10 30 10 30
BRD 83 63 85 66 / 0 20 10 10
HYR 81 66 84 63 / 0 20 20 10
ASX 83 65 82 61 / 0 20 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SHORT TERM...MELDE
LONG TERM...JJM
AVIATION...JJM
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
1204 AM CDT MON AUG 31 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 400 PM CDT SUN AUG 30 2015
WATER VAPOR IMAGERY ALONG WITH RAP H5 HEIGHT ANALYSIS SHOWS UPPER
RIDGING BUILDING IN THIS AFTERNOON. A TROUGH EJECTING ACROSS THE
NRN ROCKIES HAS ALLOWED A BROAD AREA OF SFC LOW PRESSURE TO FORM
ACROSS ERN MT/NRN NODAK/SRN CANADA. IT IS THIS LOW THAT HAS
RESULTED IN AN INCREASING PRESSURE GRADIENT AND THE STRONGER SOUTH
WINDS WE HAVE SEEN TODAY.
IT IS THESE SOUTH WINDS THAT MAKE THE FORECAST FOR TONIGHT TRICKY.
NAM BUFR SOUNDINGS MONDAY MORNING LOOK LIKE CARBON COPIES OF THE MPX
SOUNDING THIS MORNING...WHICH OF COURSE WAS ASSOCIATED WITH ANOTHER
ROUND OF LOW STRATUS. STRATUS IS STILL HANGING TOUGH IN IOWA AND
WITH THE PATTERN TO OUR SOUTHEAST NOT MUCH DIFFERENT FROM WHAT WE
HAVE SEEN THE PAST COUPLE OF NIGHTS...EXPECT STRATUS TO EXPAND AGAIN
TONIGHT...THE QUESTION IS JUST HOW FAR NW DOES IT COME. ONE BIG
DIFFERENCE BETWEEN TODAY AND THE PAST COUPLE OF DAYS IS WE HAVE
STRONGER WINDS AND BETTER BOUNDARY LAYER MIXING TODAY. THE GRADIENT
AND ASSOCIATED WINDS WILL REMAIN IN PLACE THROUGH THE NIGHT...ADDING
A LAYER OF UNCERTAINTY TO THE SKY FORECAST. FOR NOW...DID A SOFT
PLAY FOR THE STRATUS...WITH 40/50% COVERAGE FROM SOUTH CENTRAL MN
INTO EAST CENTRAL MN AND WRN WI LATE TONIGHT/EARLY MONDAY MORNING
AND WILL LET FUTURE SHIFTS UP SKY COVER IF NEED BE WHEN THERE IS A
BETTER HANDLE ON WHERE IT IS GOING.
FOR MONDAY...THE PREVIOUSLY MENTIONED LOW WELL SEND A FRONT ACROSS
THE DAKOTAS...APPROACHING WEST CENTRAL MN BY THE AFTERNOON.
HOWEVER...WE ARE NOT ANTICIPATING ANY ACTIVITY ALONG THE FRONT THIS
FAR SOUTH...SO WE REMOVED WHAT SMALL POPS WERE MENTION MONDAY
AFTERNOON IN OUR NW. BESIDE NONE OF THE HI-RES...DETERMINISTIC...OR
ENSEMBLE MODELS SHOWING ANY PRECIP IN OUR AREA...FORECAST SOUNDINGS
AT AXN AND SURROUNDING SITES SHOW A STRONG WARM NOSE BETWEEN H8 AND
H7 THAT LOOKS TO KEEP A LID ON DEEP MOIST CONVECTION THIS FAR SOUTH.
IN ADDITION...THE WAVE AND ASSOCIATED HEIGHT FALLS DRIVING THIS
FRONT ARE GOING FROM MT TO HUDSON BAY...STAYING WELL NW OF THE
MPX AREA...SO FEEL CONFIDENT IN THE DRY FORECAST FOR MONDAY.
BESIDE DRY...ALL OF THE MODELS SHOW 925-850 TEMPS IN WRN MN DROPPING
A COUPLE OF DEGS C MONDAY AFTERNOON COMPARED TO WHAT WE ARE SEEING
TODAY...SO EXPECT HIGHS TO BE NO WARMER THAN WHAT WE ARE SEEING
TODAY AND LIKELY A COUPLE OF DEGREES COOLER IN WRN MN.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 400 PM CDT SUN AUG 30 2015
NO BIG CHANGES TO THE LONG TERM FORECAST AS THE PATTERN STILL
FAVORS RIDGING IN THE CENTRAL CONUS AND ABOVE NORMAL TEMPERATURES
LASTING INTO LABOR DAY WEEKEND.
THE LONGWAVE RIDGE AXIS WILL CONTINUE TO SHIFT EAST ON
TUESDAY...BUT THE BIGGEST RESERVOIR OF WARMTH WILL LINGER FROM THE
FOUR CORNERS UP THROUGH THE NORTHERN PLAINS. THE NAEFS
STANDARDIZED 850MB TEMPERATURE ANOMALIES ARE COMMONLY BETWEEN TWO
AND THREE SIGMA OVER THE NEXT WEEK IN THESE AREAS. AS THE 500MB
RIDGE AXIS SLIDES EAST ON TUESDAY THE LONGWAVE PATTERN LOSES SOME
OF ITS AMPLITUDE AND THE 850MB TEMPERATURE ADVECTION DECREASES
BEFORE REACHING THE FORECAST AREA. AS A RESULT...THE FORECAST AREA
WILL MAINTAIN MID 80S FOR HIGHS AS WE HEAD TOWARD MID WEEK...BUT
THE TEMPERATES WILL NOT APPROACH THE MID /AND EVEN UPPER/ 90S
THAT ARE CURRENTLY BEING OBSERVED IN THE DAKOTAS THIS AFTERNOON.
WESTERN MN IS ALREADY SEEING DEWPOINTS IN THE UPPER 60S AND
EASTERN MN AND WESTERN WI WILL SOON FOLLOW...THESE DEWPOINTS WILL
LINGER THROUGH THE WEEK AND THE DEWPOINT WILL MOST LIKELY HIT 70
DEGREES IN MANY LOCATIONS THIS WEEK. IN THE WED-THU TIME
FRAME...MUCH OF THE 12Z GUIDANCE HINTS AT THE CHANCE FOR RAIN WITH
MOISTURE TRANSPORT EMBEDDED IN THE LOW LEVEL SOUTHWEST FLOW. THE
FORCING ISNT EXTREMELY...BUT THERE IS ELEVATED INSTABILITY AND
THE CAP ISNT OVERLY STRONG EITHER WITH THE 12-14C AIR AT 700MB
REMAINING WEST OF THE AREA IN THE DAKOTAS. THEREFORE...WE
MAINTAINED THE SMALL POPS IN THE FORECAST...BUT ADMITTEDLY THERE
IS LOW CONFIDENCE ON TIMING/AMOUNTS AND EVEN IF THERE WILL BE MUCH
CONVECTIVE INITIATION LOCALLY.
THE PERSISTENT TROUGH OVER THE GULF OF ALASKA AND PACIFIC
NORTHWEST FINALLY LOOKS TO MAKE SOME EASTERN PROGRESS AS WE HEAD
TOWARD THE BACK HALF OF LABOR DAY WEEKEND. THE OPERATIONAL
GUIDANCE AND ENSEMBLE OUTPUT HAS SLIGHTLY SLOWED THE ARRIVAL OF
THE COLD FRONT...BUT AT THE VERY LEAST WE CAN SAY NEXT WEEKEND
LOOKS MORE UNSETTLED WITH A PATTERN SHIFT LOCALLY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1203 AM CDT MON AUG 31 2015
BEGINNING TO SEE CONDITIONS BECOME FAVORABLE FOR RAPID STRATUS
DEVELOPMENT AT TAF ISSUANCE TIME. VISIBILITIES HAVE FALLEN TO
BETWEEN 5-7SM OVER MUCH OF THE AREA AND A FEW SITES ARE NOW
REPORTING SCT-BKN IFR CIGS ACROSS NWRN IOWA/SWRN MN/ERN SD. KHCD
AND KSTC HAVE ALSO HAD SCT007/SCT010 OBS RESPECTIVELY. SO...IT
MAY TAKE ANOTHER COUPLE HOURS BUT STILL BELIEVE WIDESPREAD IFR
CIGS ARE LIKELY TONIGHT INTO EARLY MONDAY.
KMSP...PUSHED BACK THE TIMING OF THE ARRIVAL OF IFR CIGS A COUPLE
HOURS TO 07Z...WITH THE POTENTIAL FOR PERIODIC EPISODES OF VFR
UNTIL LATE TONIGHT. MORE LIKELY THAN NOT...TONIGHT WILL BE A
REPEAT OF THE LAST COUPLE.
/OUTLOOK FOR KMSP/
TUE-THU...VFR WINDS S 5-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
823 PM MDT TUE SEP 1 2015
.UPDATE...
MADE SOME MINOR TWEAKS TO THE WINDS FOR THE UPDATE. THE CURRENT
LAV AND HRRR GUIDANCE FITS WITH THE TREND OF NORTH TO
NORTHEASTERLY WINDS OVER THE EASTERN ZONES. AS A WEAK SURFACE LOW
DEVELOPED OVER THE BIGHORN BASIN THIS AFTERNOON...THE PRESSURE
GRADIENT SHIFTED A LITTLE MORE QUICKLY THAN PREVIOUS GUIDANCE HAD.
REIMER
&&
.SHORT TERM...VALID FOR WED AND THU...
PREVIOUS FORECAST WAS IN GOOD SHAPE AND HAVE MADE ONLY MINOR
ADJUSTMENTS FOR THE AFTERNOON PACKAGE. UPPER LOW OFF THE BC COAST
ON WATER VAPOR IMAGERY THIS AFTERNOON WILL ROTATE SLOWLY SE
THROUGH THE PERIOD...AS A STRONG JET MOVES AROUND THE BASE OF THE
LOW TO THE E SIDE OF THE SYSTEM. AIRMASS WILL REMAIN DRY IN THIS
SW FLOW ALOFT UNTIL THU WHEN THE FLOW ALOFT BECOMES MORE SOUTHERLY
AND ADVECTS MONSOONAL MOISTURE INTO THE AREA. THUS KEPT A DRY
FORECAST THROUGH THU MORNING...THEN CONTINUED THE LOW POPS OVER
THE FAR W INCLUDING THE MOUNTAINS THU AFTERNOON. JET
DIVERGENCE...SHORTWAVE ENERGY AND MOISTURE WILL BE ON THE INCREASE
THU NIGHT IN A POST-FRONTAL REGIME WHICH WILL BRING MORE
WIDESPREAD...BUT LOW...CHANCES OF PRECIPITATION TO THE REGION.
STEEP LAPSE RATES SUPPORTED KEEPING THUNDER IN THE FORECAST. THE
MODELS WERE NOT IN GOOD AGREEMENT REGARDING HOW MUCH QPF THE
REGION WOULD RECEIVE THU NIGHT.
MEANWHILE...ON WED...MODELS STILL SHOWED HOT AND DRY CONDITIONS
ACROSS THE AREA. KMLS WILL APPROACH THEIR RECORD HIGH OF 100
DEGREES. HUMIDITIES WILL FALL INTO THE TEENS WITH A BIT HIGHER
VALUES IN THE MOUNTAINS. A SURFACE LOW WILL SETTLE OVER CENTRAL TO
E PARTS OF THE AREA IN THE AFTERNOON AHEAD OF A COLD FRONT
DROPPING DOWN FROM THE N. IN GENERAL...MODELS SHOWED A DECENT
PRESSURE GRADIENT OVER THE FAR WESTERN ZONES. LOOKING AT A
COMBINATION OF MODEL TIME-HEIGHTS AND SOUNDINGS...IT APPEARED THE
BEST MIXING WOULD BE OVER THE FAR WESTERN ZONES...THEN MIXING
WOULD DECREASE FROM W TO E...DUE TO THE PROXIMITY OF THE SURFACE
LOW. THE HIGHEST WIND GUSTS TO POSSIBLY 40 MPH OR HIGHER WILL BE
OVER KLVM INTO WHEATLAND COUNTY. EXPECT GUSTY WINDS OVER HIGHER
ELEVATIONS AS WELL. PLACEMENT AND TIMING OF THE RFW LOOKS FINE FOR
NOW.
THE COLD FRONT WILL MOVE THROUGH THE AREA WED NIGHT THROUGH EARLY
THU USHERING IN COOLER CONDITIONS AND CHANCES FOR PRECIPITATION
THU NIGHT AS MENTIONED ABOVE. THE FAR S AND SE ZONES LOOK TO
REMAIN WARM AND DRY ON THU AS THE POST-FRONTAL AIRMASS DOES NOT
REACH THESE AREAS. IT WILL BE BREEZY IN THESE AREAS...BUT NOT
WINDY ENOUGH TO SUPPORT RED FLAG CONDITIONS. ARTHUR
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
STILL MUCH UNCERTAINTY RESIDES IN PASSAGE OF AN UPPER LEVEL LOW
OVER MONTANA. SOME SOLUTIONS REMAIN VERY SLOW AND WOULD KEEP COOL
TEMPERATURES IN THE REGION THROUGHOUT THE WEEKEND...THE
EURO...WHILE OTHERS ARE SLOW INITIALLY BUT THEN KICK OUT THE UPPER
TROUGH VERY QUICKLY...THE GFS/CANADIAN. WITH SO MUCH
UNCERTAINTY...FORECAST SPECIFICS AT THIS TIME ARE NOT CLEAR.
HOWEVER...ALL THE MODELS DO AGREE THAT AT SOME POINT THIS WEEKEND
WE SHOULD SEE ONE OR TWO COOL AND CLOUDY DAYS
THE PERIOD BEGINS WITH A WEAK FRONTAL BOUNDARY IN PLACE OVER THE
REGION. AS UPPER LEVEL ENERGY INCREASES IN THE BACKING
FLOW SURFACE LOW SHOULD BECOME WELL ESTABLISHED OVER THE DAKOTAS.
THIS WILL HELP MOVE THE REST OF THE FRONT THROUGH THE ENTIRE
FORECAST AREA. COOLER NORTHEAST FLOW SHOULD DEVELOP AS A RESULT
OF THE SURFACE TROUGH TO OUR EAST. MOST LOCATIONS WEST OF BILLINGS
WILL SEE GOOD RAIN CHANCES AS BETTER FORCING ALOFT ROTATES
THROUGH THE TROUGH TO THE WEST. SOME MID-LEVEL CAPPING...DUE TO A
DRYSLOT...COULD KEEP CONDITIONS DRIER AND WARMER OVER THE EAST.
FOR SATURDAY THE GFS INDICATES BETTER SHOWER THUNDERSTORM CHANCES
AS IT IS MUCH LESS AGGRESSIVE WITH THE UPPER LEVEL DRY SLOT.
MEANWHILE THE EURO AND CANADIAN KEEP VERY ISOLATED SHOWER/TSTORM
CHANCES OUT EAST AND AREAS WEST OF BILLINGS WETTER. SEEING AS THE
MOST RECENT EURO MOVED CLOSER TO THE CANADIAN WILL NOT BE
AGGRESSIVE WITH POPS. LOCATIONS WEST OF BILLINGS SHOULD BE FAIRLY
COOL WHILE EASTERN LOCATIONS WILL BE SEASONABLE UNDER THE DRY
SLOT.
THE UPPER LEVEL LOW SHOULD BEGIN TO TIGHTEN AND AS IT DEEPENS
THE SURFACE LOW TO OUR EAST...WRAP AROUND MOISTURE AND GOOD
DYNAMICS ALOFT SHOULD BRING HIGHER RAIN CHANCES FOR NEARLY THE
ENTIRE AREA. HOWEVER...WITH A FAIRLY PRONOUNCED DRY SLOT ALOFT
TEMPERATURES AND RAIN CHANCES WILL BE HIGHLY DEPENDENT ON WHERE
THE EVENTUAL UPPER LOW WRAPS UP. AFTER THE SYSTEM MOVES OUT
SOMETIME MONDAY ZONAL FLOW AND SEASONABLE CONDITIONS SHOULD
RETURN. DOBBS
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL OVER THE NEXT 24 HOURS. WINDS WILL
INCREASE TOMORROW BY EARLY AFTERNOON ESPECIALLY AT LIVINGSTON
WHERE WEST WINDS AT 20 KNOTS GUSTING TO 35 KNOTS ARE EXPECTED. THE
STRONGER WINDS WILL EXTEND AS FAR EAST AS BILLINGS. REIMER
&&
.PRELIMINARY POINT TEMP/POPS...
WED THU FRI SAT SUN MON TUE
-----------------------------------------------------------
BIL 061/093 058/078 051/070 049/065 048/062 045/072 046/078
00/U 11/B 22/T 34/T 55/T 31/U 11/U
LVM 053/089 050/077 045/068 043/065 044/059 039/072 040/078
10/N 12/T 34/T 45/T 55/T 31/U 11/U
HDN 057/097 056/083 051/074 050/070 049/066 044/074 045/080
00/B 01/B 22/T 34/T 44/T 31/U 11/U
MLS 059/099 060/086 056/075 053/071 051/071 044/071 045/078
00/U 00/B 22/T 45/T 55/T 42/T 11/U
4BQ 058/099 058/091 056/079 054/073 053/074 048/071 048/078
00/U 01/B 22/T 35/T 55/T 42/T 11/U
BHK 057/098 058/091 056/077 053/071 052/072 044/069 044/075
00/U 00/B 12/T 45/T 55/T 42/T 11/U
SHR 054/096 055/088 050/077 048/073 047/069 041/073 042/079
10/U 01/B 22/T 34/T 44/T 21/U 11/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...RED FLAG WARNING IN EFFECT FROM NOON WEDNESDAY TO MIDNIGHT
MDT WEDNESDAY NIGHT FOR ZONES 28-34-39>41-56-63>68.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
1118 PM MDT SUN AUG 30 2015
.UPDATE...
WE WILL BE MAKING A QUICK UPDATE LATE THIS EVENING TO CANCEL THE
RED FLAG WARNING THAT WAS IN EFFECT UNTIL MIDNIGHT FOR OUR CENTRAL
AND WESTERN AREAS. THE COLD FRONT HAS MOVED THROUGH THIS AREA AND
WINDS HAVE SWITCHED TO THE NORTHWEST AND WERE GUSTY FOR A BRIEF
TIME BUT HAVE SINCE RELAXED INTO THE 10 TO 20 MPH RANGE. IN
ADDITION...HUMIDITIES HAVE RISEN ABOVE 30 PERCENT ACROSS THE
AFFECTED AREA. HOOLEY
&&
.SHORT TERM...VALID FOR MON AND TUE...
A SEASONABLY STRONG COLD FRONT WILL CROSS THE REGION TONIGHT AND
LEAD INTO A PERIOD OF QUIET WEATHER MONDAY AND TUESDAY.
TONIGHT...THE 12 UTC MODELS AND MORE CONTEMPORARY HRRR MODEL RUNS
ARE IN GENERAL AGREEMENT IN SHOWING THE COLD FRONT MOVING THROUGH
THE LIVINGSTON AREA BETWEEN 6 PM AND 9 PM MDT...BILLINGS BETWEEN 7
PM AND 11 MDT...SHERIDAN BETWEEN 11 PM AND 3 AM MDT...AND MILES
CITY AND BAKER AFTER MIDNIGHT. WE EXPECT A SHIFT TO WEST-NORTHWEST
WINDS BEHIND THE FRONT WITH GUSTS TO 45 MPH BASED ON THE DEGREE OF
LOW- AND MID-LEVEL COLD AIR ADVECTION AND THERMAL GRADIENT IN THE
FRONTAL ZONE. THAT/S SUPPORTED BY MOS STATISTICAL OUTPUT /THE MAV
AND MET/ AS WELL. FORECAST SOUNDINGS DO SUGGEST THE BOUNDARY LAYER
MAY BE A BIT TOO DECOUPLED FOR FULL MOMENTUM TRANSFER OF THE 40 KT
WINDS THAT ARE SIMULATED WITHIN 3000 FT AGL OF THE GROUND...BUT WE
BELIEVE THE COLD AIR ADVECTION WILL OVERCOME THAT TENDENCY. A RED
FLAG WARNING CONTINUES THROUGH THE EVENING TO CONVEY THE RISK THIS
COLD FRONTAL PASSAGE WILL PRESENT FOLLOWING LATE-AFTERNOON MIX-OUT
OF GUSTY SOUTHWEST WINDS AND DRYING IN SOUTH CENTRAL MT.
WHERE PRECIPITATION IS CONCERNED...ISOLATED SHOWERS AND STORMS ARE
POSSIBLE WITH THE SHORTWAVE TROUGH PASSAGE DRIVING THE COLD FRONT
EASTWARD...MAINLY THIS EVENING. STRONG MID-LEVEL WINDS SUGGEST A
STRONG STORM IS POSSIBLE...BUT WE FEEL THAT RISK WILL GENERALLY BE
MITIGATED BY A LACK OF STRONGER INSTABILITY.
MONDAY...THE POST-FRONTAL AIR MASS WILL BE COOLER...DRIER...AND
STABLE. HIGHS WILL BE NEAR 80 F WITH AFTERNOON HUMIDITIES AROUND
20 PERCENT PER THE 12 UTC MULTI-MODEL CONSENSUS WE USED TO DERIVE
THE OFFICIAL FORECAST...BUT WIND/S WILL NOT BE ANYTHING TO WRITE
HOME ABOUT.
TUESDAY...DEEPER MIXING TO 700 MB OR MORE AND WARMING TEMPERATURES
ALOFT WITH SOUTHWEST FLOW WILL PROMOTE A WARM-UP INTO THE UPPER
80S AND LOWER 90S F. ATMOSPHERIC MOISTURE CONTENT WON/T CHANGE
TOO MUCH AND THE RESULT WILL BE EVEN LOWER HUMIDITIES WELL DOWN
INTO THE TEENS...THOUGH WINDS AREN/T EXPECTED TO BE STRONG ENOUGH
FOR ANY RED-FLAG-TYPE CONDITIONS. SCHULTZ
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
UPPER TROUGH OVER THE PACIFIC NORTHWEST WILL MOVE INLAND ON
WEDNESDAY AND THIS SETS UP DEEP SOUTHWEST FLOW OVER SOUTHERN
MONTANA AND NORTHERN WYOMING. HIGHS WILL APPROACH 90 DEGREES ON
WEDNESDAY AHEAD OF COLD FRONT. THIS FRONT WILL MOVE THROUGH
WEDNESDAY NIGHT AND BRING COOLER WEATHER FOR THE END OF THE WEEK.
IN FACT...THIS WILL MARK A DRAMATIC PATTERN CHANGE AS THE WESTERN
TROUGH SWINGS OVER THE NORTHERN ROCKIES THIS WEEKEND. THIS WILL
END THE WARM AND DRY REGIME AND PROVIDE COOLER TEMPERATURES AND A
CHANCE OF PRECIPITATION. SOME OF THE MOUNTAIN TOPS COULD EVEN SEE
A LITTLE SNOW SATURDAY AND SUNDAY...ALTHOUGH THE STRONGER FORCING
AND MOST LIKELY PRECIPITATION PLACEMENT...WOULD BE OVER NORTHERN
MONTANA. TWH
&&
.AVIATION...
STRONG SOUTHWEST WINDS WILL CONTINUE AT KLVM THIS AFTERNOON WITH
SOME GUSTS TO 35KTS. WIDELY SCATTERED SHOWERS AND THUNDERSTORMS
WILL DEVELOP THROUGH THIS EVENING AS A COLD FRONT APPROACHES. SOME
OF THE STORMS NORTHWEST OF BILLINGS COULD BE STRONG WITH WIND
GUSTS TO 45KTS. A COLD FRONT WILL MOVE THROUGH CENTRAL LOCATIONS
FROM KBIL TO KLVM FROM 02-04Z...KSHR 03-05Z AND KMLS AND KBHK
05-07Z. NORTHWEST WINDS WILL GUST TO 35KTS BEHIND THE FRONT.
TWH/AAG
&&
.PRELIMINARY POINT TEMP/POPS...
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 054/082 054/089 059/090 055/075 048/069 047/070 045/071
20/U 00/U 01/U 11/B 23/T 33/T 22/T
LVM 045/080 046/086 051/085 048/072 041/067 038/069 039/073
20/K 00/K 01/B 23/T 44/T 44/T 32/T
HDN 054/083 053/092 057/094 056/080 048/075 048/072 046/073
20/U 00/U 11/U 11/B 22/T 22/T 22/T
MLS 057/082 055/092 059/097 059/081 051/077 049/073 047/072
30/U 00/U 00/U 11/B 22/T 22/T 22/T
4BQ 056/080 055/092 059/096 058/082 053/079 051/071 049/070
30/U 00/U 00/U 01/U 12/T 22/T 22/T
BHK 055/079 054/091 057/095 058/081 051/080 049/073 046/070
30/N 00/U 10/U 11/U 12/T 22/T 22/T
SHR 051/083 049/091 054/092 053/082 046/076 044/070 042/071
30/U 00/U 10/U 01/B 12/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
300 PM EDT MON AUG 31 2015
.SYNOPSIS...AN UPPER LEVEL LOW WILL MOVE NORTHEASTWARD AWAY FROM THE
AREA THROUGH THE REST OF TODAY. OTHERWISE... A WEAK SURFACE TROUGH
WILL HOLD OVER EASTERN NORTH CAROLINA... WHILE HIGH PRESSURE
CENTERED OVER KENTUCKY EXTENDS OVER WESTERN NORTH CAROLINA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM MONDAY...
THE SHIELD OF TROPICAL RAIN HAS SHIFTED EAST OF THE FORECAST AREA...
WHILE THE MID LEVEL LOW HAS MOVED WELL TO OUR NE. WHILE A FEW
SHALLOW SHOWERS REMAIN POSSIBLE... THE THREAT OF ADDITIONAL
SIGNIFICANT RAINFALL WILL HOLD JUST TO OUR EAST FOR THE REMAINDER OF
THE DAY. LATEST SURFACE ANALYSIS SHOWS LOW PRESSURE JUST OFF THE CHS
COAST... AND THIS WILL TRACK TO THE NNE ALONG THE SURFACE TROUGH
OVER ERN NC... ACCOMPANIED BY A MID LEVEL WAVE NOTED ON WATER VAPOR
IMAGERY JUST UPSHEAR. EXTRAPOLATION SUGGESTS THAT THE RAIN SHIELD IS
LIKELY TO HOLD JUST TO OUR EAST OR PERHAPS BRUSH ALONG THE FAR ERN
COASTAL PLAIN AS THE LOW TRACKS OVER ERN NC... A SCENARIO NEARLY IN
LINE WITH THE LATEST HRRR RUNS. WILL RETAIN A LOW CHANCE POP OVER
THE CENTRAL/ERN FORECAST AREA INTO EARLY EVENING... THEN EXPECT DRY
WEATHER OVERNIGHT AS THE DRIER AIR NOTED ON WATER VAPOR IMAGERY TO
OUR SW CONTINUES TO OVERSPREAD ALL OF CENTRAL NC. IT`S A DIFFERENT
STORY NEAR THE GROUND HOWEVER... AS HIGHER DEWPOINTS AND LOW LEVEL
MOISTURE HOLDING OVER THE ERN HALF OF NC ALONG WITH A WET GROUND AND
LIGHT OR CALM SURFACE WINDS LEAD TO FAVORABLE CONDITIONS FOR
FOG/STRATUS DEVELOPMENT... PARTICULARLY FROM THE TRIANGLE AND FAY TO
THE EAST/NORTHEAST. EXPECT ABOVE-NORMAL LOWS FROM 67-72. -GIH
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 300 PM MONDAY...
A WEAK SURFACE PATTERN FEATURING A BROAD TROUGH OVER ERN NC AND KY-
CENTERED RIDGE EXTENDING INTO WRN NC WILL REMAIN IN PLACE... WHILE
ALOFT... HEIGHTS RISE OVER NC IN THE WAKE OF THE EXITING WAVE... AND
AHEAD OF THE LOW NOW OVER CENTRAL INDIANA. FORECAST SOUNDINGS DEPICT
FAIRLY DRY AND STABLE AIR THROUGH THE MID AND UPPER LEVELS...
ALTHOUGH A MODERATE AMOUNT OF LINGERING LOW LEVEL MOISTURE
ESPECIALLY IN THE EAST SHOULD RESULT IN SCATTERED TO BROKEN STRATOCU
PARTICULARLY FROM LATE MORNING THROUGH EARLY EVENING. ONCE THE
MORNING FOG LIFTS AND MIXES OVER THE NRN AND ERN CWA... EXPECT
GENERALLY PARTLY CLOUDY SKIES. WILL KEEP A SLIGHT CHANCE OF AN
AFTERNOON SHOWER OR STORM IN THE FAR ERN CWA... WHERE LOW LEVEL
MOISTURE WILL BE BETTER AND WHERE MUCAPE IS FORECAST TO APPROACH OR
EXCEED 1000 J/KG... BUT THE LACK OF A FOCUS FOR ASCENT AND LIMITED
MOISTURE ALOFT SHOULD KEEP COVERAGE LOW. HIGHS 88-92 WITH
THICKNESSES A BIT ABOVE NORMAL. FAIR TO PARTLY CLOUDY TUE NIGHT WITH
LOWS 69-72. -GIH
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...
A FAIRLY LOW CONFIDENCE FORECAST FOR THE EXTENT OF THE LONG TERM AS
THERE IS VERY LITTLE FORCING IN THE UPPER LEVELS WITH NO REAL
DISCERNIBLE JETS OR STRONG SHORTWAVES IN THE VICINITY OF CENTRAL NC.
THEREFORE MUCH OF THE LONG TERM FORECAST WILL BE BUILT AROUND LOWER
LEVEL FEATURES.
WEDNESDAY SHOULD BE FAIRLY UNEVENTFUL WITH VERY WEAK HIGH PRESSURE
OVER THE WESTERN ATLANTIC AND A SURFACE LOW MOVING THROUGH EASTERN
CANADA. THE SURFACE FRONT ASSOCIATED WITH THIS FEATURE WILL BE VERY
WEAK WITH NOT MUCH OF AN AIRMASS CHANCE BUT MAYBE JUST ENOUGH
FORCING FOR A SLIGHT UPTICK IN CONVECTION ON THURSDAY
AFTERNOON/EVENING WITH SHOWERS LINGERING INTO THE EARLY MORNING
HOURS ON FRIDAY.
DURING THE DAY ON FRIDAY HIGH PRESSURE WILL BEGIN TO STRENGTHEN OVER
NEW ENGLAND AND RETROGRADE SOUTHWESTWARD INTO THE MID ATLANTIC
STATES. THIS WILL HELP PUSH A BACK DOOR COLD FRONT THROUGH THE AREA
LATER ON FRIDAY AND GIVING US A COOLER AIRMASS FOR THE WEEKEND AND
INTO MONDAY.
TEMPERATURES WILL MAINLY RUN IN THE UPPER 80S/LOW 90S EARLY IN THE
PERIOD AND THEN DROP INTO THE LOW TO MID 80S FOR THE WEEKEND AND
INTO EARLY NEXT WEEK. LOWS GENERALLY IN THE MID TO UPPER 60S. PRECIP
CHANCES WILL MAINLY BE SLIGHT CHANCE THROUGH THE WORK WEEK WITH
CHANCE POPS FOR THE WEEKEND. -RE
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 125 PM MONDAY...
MVFR CONDITIONS ARE LIKELY TO DOMINATE AT INT/GSO/FAY INTO
TONIGHT... WHILE IFR/LIFR CONDITIONS ARE EXPECTED TO DOMINATE AT
RDU/RWI. A STREAM OF TROPICAL MOISTURE WHICH BROUGHT THIS MORNING`S
RAIN IS BEING PUSHED SLOWLY EASTWARD INTO COASTAL NC... BUT LOWER
CIGS REMAIN WELL BACK INTO CENTRAL NC WITH WEAK SURFACE WINDS AND
PLENTY OF LINGERING LOW LEVEL MOISTURE. THESE TWO FACTORS WILL KEEP
A HIGH CHANCE OF SUB-VFR CIGS THROUGH THIS EVENING AT CENTRAL NC
TERMINALS... ALTHOUGH INT/GSO/FAY MAY BRIEFLY BREAK OUT TO VFR THIS
AFTERNOON. CIGS SHOULD REMAIN IFR AT RDU/RWI... ALTHOUGH THESE SITES
TOO MAY BRIEFLY JUMP UP A CATEGORY TO MVFR TODAY. CLOUDS ARE
EXPECTED TO BECOME SCT AT INT/GSO OVERNIGHT... BUT WITH A THREAT OF
MVFR TO IFR VSBYS IN FOG. AT FAY AND ESPECIALLY AT RDU/RWI... CIGS
ARE EXPECTED TO HOLD AT IFR OR EVEN LIFR OVERNIGHT INTO TUE
MORNING... WITH A RISK OF MVFR TO IFR FOG. LOW CLOUDS SHOULD SLOWLY
LIFT AND MIX OUT TO MVFR THEN VFR TUE MORNING IN THE 14-18Z TIME
FRAME... WITH CIGS AT RWI LAST TO LIFT TO VFR.
LOOKING BEYOND 18Z TUE: VFR CONDITIONS ARE EXPECTED TUE AFTERNOON
INTO TUE NIGHT... BUT MVFR TO IFR FOG IS POSSIBLE LATE TUE NIGHT
INTO WED MORNING. VFR CONDITIONS SHOULD THEN PREVAIL THROUGH SAT.
SCATTERED SUB-VFR SHOWERS/STORMS ARE POSSIBLE EACH AFTERNOON/EVENING
WED THROUGH SAT... ALTHOUGH FORECAST CONFIDENCE IS QUITE LOW WITH
DETAILS OF POSSIBLE TIMING OR COVERAGE. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...KS
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...ELLIS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
125 PM EDT MON AUG 31 2015
.SYNOPSIS...AN UPPER LEVEL LOW WILL MOVE NORTHEASTWARD AWAY FROM THE
AREA THROUGH THE REST OF TODAY. OTHERWISE... A WEAK SURFACE TROUGH
WILL HOLD OVER EASTERN NORTH CAROLINA... WHILE HIGH PRESSURE
CENTERED OVER KENTUCKY EXTENDS OVER WESTERN NORTH CAROLINA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 935 AM MONDAY...
EARLIER UPDATE TARGETED THE CENTRAL/ERN CWA WITH HIGHEST POPS
(LIKELY TO CATEGORICAL) FOR THE ONGOING TROPICAL RAINFALL. THESE HIGH
POPS WILL SHIFT SLOWLY EASTWARD OVER THE NEXT SEVERAL HOURS AS THE
UPPER LEVEL LOW THAT CROSSED THE STATE EARLIER THIS MORNING HEADS
NNE INTO VA. RAIN RATES OF 1-2 INCHES PER HOUR HAVE BEEN COMMON...
ENOUGH TO PRODUCE SOME MINOR URBAN AND STREET FLOODING AND RISING
CREEKS BUT UNDER FLOODING THRESHOLDS... AND THIS RAIN SHOULD
ACTUALLY BE BENEFICIAL FOR MOST. WATER VAPOR IMAGERY SHOWS DRYING
OVER THE WRN CWA... SO WHILE A FEW WRAPAROUND SHOWERS ARE POSSIBLE
IN AREAS NW OF THE TRIANGLE... THESE SHOULD GENERATE LITTLE
ADDITIONAL RAINFALL. EASTERN SECTIONS ESPECIALLY ALONG AND EAST OF I-
95 MAY SEE A SLOWER TAPERING OF THE WIDESPREAD MODERATE RAIN...
GIVEN THAT ANOTHER WAVE NOW APPROACHING SAVANNAH GA WILL BE TRACKING
TO THE N OR NNE... SLOWING THE ARRIVAL OF DRIER AIR... AND THIS
TREND IS NOTED WELL IN THE RECENT RAP RUNS. POPS WILL START OUT
RANGING FROM ISOLATED AT MOST WEST TO CATEGORICAL EAST... TRENDING
DOWNWARD WEST TO EAST THROUGH THE REST OF THE DAY. ANY INSTABILITY
SHOULD BE MARGINAL... WITH MUCAPE MOSTLY HOLDING AT OR BELOW 1000
J/KG... SO WILL KEEP ANY THUNDER MENTION AT ISOLATED TO SCATTERED AT
MOST. TEMPS ARE A TOUGH CALL GIVEN THE GREATLY LIMITED INSOLATION IN
THE EAST... SO EXPECT HIGHS IN THE LOW-MID 80S WEST AND NEAR 80 TO
LOWER 80S EAST... WITH THESE EASTERN HIGHS NOT BEING REACHED UNTIL
VERY LATE IN THE DAY. -GIH
LOWS TONIGHT IN THE UPPER 60S TO LOWER 70S.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 345 AM MONDAY...
A WEAK/NONDESCRIPT SFC PATTERN WILL EXTEND ACROSS THE AREA ON
TUESDAY WITH HEIGHTS ALOFT BUILDING OVER THE SOUTHEAST AS THE
SUBTROPICAL RIDGE OVER THE SOUTHWEST ATLANTIC RETROGRADES WESTWARD.
OTHER THAN DAYTIME HEATING ATOP A SEASONABLY MOIST AIRMASS...
FORCING MECHANISM IS LACKING WITH ISOLATED DIURNAL CONVECTION AT
BEST.
HIGHS IN THE UPPER 80S TO LOWER 90S. LOWS IN THE UPPER 60S TO LOWER
70S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 310 AM MONDAY...
MEDIUM RANGE MODELS ARE IN GENERAL AGREEMENT IN SHOWING A WEAK
DISTURBANCE ALOFT TRACKING FROM THE OHIO VALLEY MIDWEEK TO ACROSS
CENTRAL NC THURSDAY OR THURSDAY NIGHT. HOWEVER... THE LATEST GFS AND
ECMWF CONTINUE TO DISAGREE WRT WHAT HAPPENS TO IT. THE LATEST ECMWF
CONTINUES TO SHOW THE S/W SHIFTING TO THE EAST/SOUTHEAST AND
OFFSHORE BY THURSDAY AFTERNOON... WITH BRIEF S/W RIDGING BUILDING
OVER THE AREA BEFORE A WEAK MID LEVEL LOW LIFTS NORTHEASTWARD OUT OF
THE NORTHWEST GULF OF MEXICO AND INTO THE CAROLINAS BY FRIDAY NIGHT
AND LINGERING THROUGH THE END OF THE FORECAST PERIOD. MEANWHILE...
THE LATEST GFS IS SLOWER MOVING THE INITIAL S/W DISTURBANCE THROUGH
THE AREA ON THURSDAY... LINGERING INTO FRIDAY MORNING. THE S/W IS
THEN EXPECTED TO CLOSE OFF INTO A MID LEVEL LOW AND CONTINUE TO
SLOWLY SINK SOUTHWARD AS A STRONG 595 DECAMETER HIGH BEGINS TO BUILD
SOUTHWARD TOWARDS CENTRAL NC. GIVEN THIS PATTERN... THE LOW IN THE
NORTHWESTERN GULF OF MEXICO ACTUALLY SINKS FURTHER SOUTH AND NOT IN
THE DIRECTION OF CENTRAL. AT THE SURFACE... WE SHOULD SEE SOME TYPE
OF WEAK SURFACE TROUGH TRACK ACROSS THE AREA WITH THE INITIAL S/W
DISTURBANCE... WITH SURFACE HIGH PRESSURE BUILDING/EXTENDING INTO
CENTRAL NC FROM THE NORTH/NORTHEAST DURING THE WEEKEND. THUS... AT
THIS TIME... WILL KEEP POPS GENERALLY LOW... SLIGHT CHANCE TO LOW
END CHANCE DURING THE MEDIUM RANGE... GIVEN THE UNCERTAINTY IN WHAT
WILL GENERALLY BE MEAN RIDING OVER THE EASTERN HALF OF THE COUNTRY
DURING THIS TIME (WITH THE EMBEDDED DISTURBANCES/WEAK CLOSED LOWS).
HIGH TEMPS WILL GENERALLY BE NEAR TO SLIGHTLY ABOVE NORMAL FOR THE
MID TO LATE WEEK TIME FRAME... THEN NEAR NORMAL TO POSSIBLY SLIGHT
BELOW NORMAL FOR THE WEEKEND. LOW TEMPS ARE EXPECTED TO BE NEAR TO
SLIGHTLY ABOVE NORMAL DURING THE PERIOD.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 125 PM MONDAY...
MVFR CONDITIONS ARE LIKELY TO DOMINATE AT INT/GSO/FAY INTO
TONIGHT... WHILE IFR/LIFR CONDITIONS ARE EXPECTED TO DOMINATE AT
RDU/RWI. A STREAM OF TROPICAL MOISTURE WHICH BROUGHT THIS MORNING`S
RAIN IS BEING PUSHED SLOWLY EASTWARD INTO COASTAL NC... BUT LOWER
CIGS REMAIN WELL BACK INTO CENTRAL NC WITH WEAK SURFACE WINDS AND
PLENTY OF LINGERING LOW LEVEL MOISTURE. THESE TWO FACTORS WILL KEEP
A HIGH CHANCE OF SUB-VFR CIGS THROUGH THIS EVENING AT CENTRAL NC
TERMINALS... ALTHOUGH INT/GSO/FAY MAY BRIEFLY BREAK OUT TO VFR THIS
AFTERNOON. CIGS SHOULD REMAIN IFR AT RDU/RWI... ALTHOUGH THESE SITES
TOO MAY BRIEFLY JUMP UP A CATEGORY TO MVFR TODAY. CLOUDS ARE
EXPECTED TO BECOME SCT AT INT/GSO OVERNIGHT... BUT WITH A THREAT OF
MVFR TO IFR VSBYS IN FOG. AT FAY AND ESPECIALLY AT RDU/RWI... CIGS
ARE EXPECTED TO HOLD AT IFR OR EVEN LIFR OVERNIGHT INTO TUE
MORNING... WITH A RISK OF MVFR TO IFR FOG. LOW CLOUDS SHOULD SLOWLY
LIFT AND MIX OUT TO MVFR THEN VFR TUE MORNING IN THE 14-18Z TIME
FRAME... WITH CIGS AT RWI LAST TO LIFT TO VFR.
LOOKING BEYOND 18Z TUE: VFR CONDITIONS ARE EXPECTED TUE AFTERNOON
INTO TUE NIGHT... BUT MVFR TO IFR FOG IS POSSIBLE LATE TUE NIGHT
INTO WED MORNING. VFR CONDITIONS SHOULD THEN PREVAIL THROUGH SAT.
SCATTERED SUB-VFR SHOWERS/STORMS ARE POSSIBLE EACH AFTERNOON/EVENING
WED THROUGH SAT... ALTHOUGH FORECAST CONFIDENCE IS QUITE LOW WITH
DETAILS OF POSSIBLE TIMING OR COVERAGE. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...KS
NEAR TERM...HARTFIELD/CBL
SHORT TERM...CBL
LONG TERM...77
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
935 AM EDT MON AUG 31 2015
.SYNOPSIS...AN UPPER LEVEL LOW WILL MOVE NORTHEASTWARD AWAY FROM THE
AREA LATE THIS MORNING...AS A WEAK SURFACE TROUGH PUSHES TOWARD THE
COAST. ASIDE FROM A WEAK WAVE APPROACHING FROM THE OHIO VALLEY
MIDWEEK...GENERAL HIGH PRESSURE WILL RESIDE OVER THE AREA AS DEEP
MOISTURE IS SHUNTED TO OUR SOUTH.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 935 AM MONDAY...
EARLIER UPDATE TARGETED THE CENTRAL/ERN CWA WITH HIGHEST POPS
(LIKELY TO CATEGORICAL) FOR THE ONGOING TROPICAL RAINFALL. THESE HIGH
POPS WILL SHIFT SLOWLY EASTWARD OVER THE NEXT SEVERAL HOURS AS THE
UPPER LEVEL LOW THAT CROSSED THE STATE EARLIER THIS MORNING HEADS
NNE INTO VA. RAIN RATES OF 1-2 INCHES PER HOUR HAVE BEEN COMMON...
ENOUGH TO PRODUCE SOME MINOR URBAN AND STREET FLOODING AND RISING
CREEKS BUT UNDER FLOODING THRESHOLDS... AND THIS RAIN SHOULD
ACTUALLY BE BENEFICIAL FOR MOST. WATER VAPOR IMAGERY SHOWS DRYING
OVER THE WRN CWA... SO WHILE A FEW WRAPAROUND SHOWERS ARE POSSIBLE
IN AREAS NW OF THE TRIANGLE... THESE SHOULD GENERATE LITTLE
ADDITIONAL RAINFALL. EASTERN SECTIONS ESPECIALLY ALONG AND EAST OF I-
95 MAY SEE A SLOWER TAPERING OF THE WIDESPREAD MODERATE RAIN...
GIVEN THAT ANOTHER WAVE NOW APPROACHING SAVANNAH GA WILL BE TRACKING
TO THE N OR NNE... SLOWING THE ARRIVAL OF DRIER AIR... AND THIS
TREND IS NOTED WELL IN THE RECENT RAP RUNS. POPS WILL START OUT
RANGING FROM ISOLATED AT MOST WEST TO CATEGORICAL EAST... TRENDING
DOWNWARD WEST TO EAST THROUGH THE REST OF THE DAY. ANY INSTABILITY
SHOULD BE MARGINAL... WITH MUCAPE MOSTLY HOLDING AT OR BELOW 1000
J/KG... SO WILL KEEP ANY THUNDER MENTION AT ISOLATED TO SCATTERED AT
MOST. TEMPS ARE A TOUGH CALL GIVEN THE GREATLY LIMITED INSOLATION IN
THE EAST... SO EXPECT HIGHS IN THE LOW-MID 80S WEST AND NEAR 80 TO
LOWER 80S EAST... WITH THESE EASTERN HIGHS NOT BEING REACHED UNTIL
VERY LATE IN THE DAY. -GIH
LOWS TONIGHT IN THE UPPER 60S TO LOWER 70S.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 345 AM MONDAY...
A WEAK/NONDESCRIPT SFC PATTERN WILL EXTEND ACROSS THE AREA ON
TUESDAY WITH HEIGHTS ALOFT BUILDING OVER THE SOUTHEAST AS THE
SUBTROPICAL RIDGE OVER THE SOUTHWEST ATLANTIC RETROGRADES WESTWARD.
OTHER THAN DAYTIME HEATING ATOP A SEASONABLY MOIST AIRMASS...
FORCING MECHANISM IS LACKING WITH ISOLATED DIURNAL CONVECTION AT
BEST.
HIGHS IN THE UPPER 80S TO LOWER 90S. LOWS IN THE UPPER 60S TO LOWER
70S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 310 AM MONDAY...
MEDIUM RANGE MODELS ARE IN GENERAL AGREEMENT IN SHOWING A WEAK
DISTURBANCE ALOFT TRACKING FROM THE OHIO VALLEY MIDWEEK TO ACROSS
CENTRAL NC THURSDAY OR THURSDAY NIGHT. HOWEVER... THE LATEST GFS AND
ECMWF CONTINUE TO DISAGREE WRT WHAT HAPPENS TO IT. THE LATEST ECMWF
CONTINUES TO SHOW THE S/W SHIFTING TO THE EAST/SOUTHEAST AND
OFFSHORE BY THURSDAY AFTERNOON... WITH BRIEF S/W RIDGING BUILDING
OVER THE AREA BEFORE A WEAK MID LEVEL LOW LIFTS NORTHEASTWARD OUT OF
THE NORTHWEST GULF OF MEXICO AND INTO THE CAROLINAS BY FRIDAY NIGHT
AND LINGERING THROUGH THE END OF THE FORECAST PERIOD. MEANWHILE...
THE LATEST GFS IS SLOWER MOVING THE INITIAL S/W DISTURBANCE THROUGH
THE AREA ON THURSDAY... LINGERING INTO FRIDAY MORNING. THE S/W IS
THEN EXPECTED TO CLOSE OFF INTO A MID LEVEL LOW AND CONTINUE TO
SLOWLY SINK SOUTHWARD AS A STRONG 595 DECAMETER HIGH BEGINS TO BUILD
SOUTHWARD TOWARDS CENTRAL NC. GIVEN THIS PATTERN... THE LOW IN THE
NORTHWESTERN GULF OF MEXICO ACTUALLY SINKS FURTHER SOUTH AND NOT IN
THE DIRECTION OF CENTRAL. AT THE SURFACE... WE SHOULD SEE SOME TYPE
OF WEAK SURFACE TROUGH TRACK ACROSS THE AREA WITH THE INITIAL S/W
DISTURBANCE... WITH SURFACE HIGH PRESSURE BUILDING/EXTENDING INTO
CENTRAL NC FROM THE NORTH/NORTHEAST DURING THE WEEKEND. THUS... AT
THIS TIME... WILL KEEP POPS GENERALLY LOW... SLIGHT CHANCE TO LOW
END CHANCE DURING THE MEDIUM RANGE... GIVEN THE UNCERTAINTY IN WHAT
WILL GENERALLY BE MEAN RIDING OVER THE EASTERN HALF OF THE COUNTRY
DURING THIS TIME (WITH THE EMBEDDED DISTURBANCES/WEAK CLOSED LOWS).
HIGH TEMPS WILL GENERALLY BE NEAR TO SLIGHTLY ABOVE NORMAL FOR THE
MID TO LATE WEEK TIME FRAME... THEN NEAR NORMAL TO POSSIBLY SLIGHT
BELOW NORMAL FOR THE WEEKEND. LOW TEMPS ARE EXPECTED TO BE NEAR TO
SLIGHTLY ABOVE NORMAL DURING THE PERIOD.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 657 AM MONDAY...
DAMPENING MID-LEVEL OVER THE WESTERN CAROLINAS WILL MOVE NORTHEASTWARD
ACROSS THE AREA THIS MORNING AND OFF THE MID-ATLANTIC COAST BY THE
AFTERNOON. ASSOCIATED PLUME OF TROPICAL MOISTURE OVER THE AREA WILL
EVENTUALLY SHIFT OFFSHORE BY THE AFTERNOON. EXPECT WIDESPREAD RAIN
TO MOVE STEADILY WEST TO EAST WITH ASSOCIATED IFR TO MVFR
CEILINGS/VISIBILITIES.
AS THE SYSTEM LIFTS AWAY FROM THE AREA AND THE TROPICAL MOISTURE
PLUME SHIFTS OFFSHORE...CONDITIONS SHOULD IMPROVE TO VFR FROM WEST
TO EAST DURING THE EARLY TO MID AFTERNOON. DAYTIME HEATING COULD
ALLOW FOR ISOLATED TO SCATTERED SHOWERS DURING THE
AFTERNOON...ALTHOUGH CONFIDENCE IS TOO LOW TO INCLUDE AT THIS TIME.
EASTERN TERMINALS COULD SEE WIDESPREAD STRATUS/FOG MONDAY
NIGHT/TUESDAY MORNING WITH VFR CONDITIONS RETURNING ON TUESDAY.
OUTSIDE OF ISOLATED TO WIDELY SCATTERED DIURNAL CONVECTION...EXPECT
PREDOMINATELY VFR CONDITIONS TUESDAY NIGHT THROUGH FRIDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...KS
NEAR TERM...HARTFIELD/CBL
SHORT TERM...CBL
LONG TERM...77
AVIATION...CBL
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
951 PM CDT TUE SEP 1 2015
.UPDATE...
ISSUED AT 941 PM CDT TUE SEP 1 2015
THUNDER CHANCES STILL THE CHALLENGE TONIGHT. THE HRRR WHICH WAS
OVERLY AGGRESSIVE IN DEVELOPING STORMS OVER OUR WESTERN FA HAS NOW
BACKED OFF AND FOCUSING DEVELOPMENT OVER SW MN WHERE THE MORE
PROMINENT LOW LEVEL JET IS TAKING SHAPE. A FEW OF THE SHORT RANGE
MODELS CONTINUE WITH SOME MODEST DEVELOPMENT LATER TONIGHT SO WILL
KEEP SLIGHT CHANCES GOING AS NOCTURNAL DEVELOPMENT SOMETIMES
FICKLE. BEST LOW LEVEL MOISTURE FLUX IS OVER THE WESTERN FA SO
HAVE ADDED SOME PATCHY FOG TO THIS AREA AS A START.
UPDATE ISSUED AT 645 PM CDT TUE SEP 1 2015
NO CHANGES NEEDED THIS UPDATE PERIOD.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 325 PM CDT TUE SEP 1 2015
500 MB SHORT WAVE NOTED IN SOUTHEASTERN SOUTH DAKOTA MOVING
NORTHEAST. A BAND OF SHOWERS ARE WITH THIS SYSTEM. FOR TONIGHT
QUESTION IS PRECIP CHANCES OVERNIGHT INTO WED MORNING MAINLY FOR
NE ND INTO NW MN. FOR THE PAST COUPLE OF DAYS MODELS HAVE
INDICATED THREAT FOR SOME CONVECTION TO DEVELOP NR 06Z IN THE MID
RRV AND THE MOVE NORTHEAST THROUGH LAKE OF THE WOODS REGION BY
12Z. 12Z MODELS TODAY SHOW TO SOME DEGREE THE SAME THING...BUT
MORE GFS IN THIS CASE AS MOST SHORT RANGE MODELS SUCH AS THE HRRR
AND RAP DONT SHOW (AT LEAST WITH MIDDAY AND EARLY AFTN RUNS).
THERE IS AN IMPRESSIVE LOW-850 MB MOISTURE RETURN THIS EVENING-
OVERNIGHT. SEEING 70 DEW PTS ALONG THE SD/ND BORDER INTO THE
ALEXANDRIA AREA WHILE MOST OF OUR FCST AREA HAS DEW PTS IN THE
50S. SO WILL SEE A MOISTURE SURGE TONIGHT AND INSTABILITY INCREASE
IN THE 850 MB LAYER 06Z-12Z PERIOD WHEN A FEW HUNDRED 850 MB CAPE
AVAILABLE. PROBLEM IS LOW LEVEL JET IS VERY WEAK 20 KTS MAYBE. BUT
WILL SIDE WITH CONSISTENCY AND KEEP LOW POPS IN BUT HAVE THEM
06Z-12Z....EXTENDING THEM A FEW HOURS PAST 12Z IN LAKE OF THE
WOODS. WEDNESDAY WILL BE MUCH MORE HUMID AND WARM.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 325 PM CDT TUE SEP 1 2015
HOT AND HUMID ON THURSDAY WITH MID 80S EAST TO LOW 90S WEST. WILL
MAINTAIN A LOW THREAT FOR PRECIP LATE THURSDAY NIGHT IN ERN
ND...THEN KEEP CHC POPS ON FRIDAY. UNCERTAIN HOW EVENT WILL PLAY
OUT BUT WILL HAVE SEVERAL SHORT WAVES AND SFC LOWS MOVE NORTHEAST
ALONG A FRONTAL BOUNDARY WHICH WILL BE OVER OR NEAR OUR AREA. EACH
ONE GIVING GOOD CHANCES FOR SHOWERS AND THUNDERSTORMS STARTING
LATE FRIDAY. DAY TO DAY TIMING OF COURSE IS DIFFICULT AT THIS
STAGE.
SATURDAY TO TUESDAY...MODELS IN GOOD AGREEMENT WITH THE GENERAL
500MB SOUTHWEST FLOW ALOFT AND EVOLUTION WITH A CLOSED STRONG SHORT
WAVE MOVING OVER THE NORTHERN PLAINS EARLY NEXT WEEK. AS A RESULT AN
ACTIVE WEATHER PATTERN WITH SEVERAL ROUNDS OF CONVECTIVE ACTIVITY
CAN BE EXPECTED FOR THE REGION OVER THE HOLIDAY WEEKEND.
UNCERTAINTIES EXIST WITH THE TIMING AND PLACEMENT OF THE LEAD WAVE
AND THE STRONGER SHORT WAVE ON MONDAY. CURRENTLY A LEAD WAVE IS
EXPECTED TO BRING A ROUND OF THUNDERSTORMS FRIDAY NIGHT WITH ANOTHER
ROUND SATURDAY NIGHT BEFORE THE THE LIGHTER WRAP AROUND PCPN ON
SUNDAY AFTN AND EARLY MONDAY. GIVEN THE AMPLE MOISTURE IN
PLACE...PWATS APPROACHING 2 INCHES...HEAVY RAIN WILL BE POSSIBLE
WITH ANY STORM. TEMPERATURES WILL BE WARMEST ON SATURDAY WITH LOW
80S IN THE SE HALF OF THE FA AND 70S IN THE NW...HIGHLY INFLUENCED
BY EXPECTED CLOUD COVER. A COOLER...CLOSER TO AVERAGE TEMP REGIME IS
EXPECTED WITH 70S SUNDAY TO TUE BEHIND DEPARTING SHORT WAVE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 645 PM CDT TUE SEP 1 2015
MAIN CHALLENGE THIS PERIOD IS FOG AND T POTENTIAL LATER TONIGHT.
AS DEWPOINTS INCREASE TONIGHT SOME POTENTIAL FOR FOG DEVELOPMENT
ACROSS THE SOUTH. MIXING AND POTENTIAL MID CLOUD DEVELOPMENT MAY
LIMIT ANY FOG AS GUIDANCE NOT SHOWING ANY DEVELOPMENT. ALSO BAND
OF ENHANCED WARM ADVECTION MAY AID IN ISOLATED STORM DEVELOPMENT
WITH WEAK LOW LEVEL JET HOWEVER PLENTY OF CIN TO OVERCOME SO FOR
NOW HAVE LEFT BR AND T MENTION OUT OF TAFS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...VOELKER
SHORT TERM...RIDDLE
LONG TERM...JK/RIDDLE
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
944 PM CDT TUE SEP 1 2015
.UPDATE...
ISSUED AT 939 PM CDT TUE SEP 1 2015
THE 22-01 UTC HRRR ITERATIONS CONTINUE TO EXPAND THE COVERAGE OF
FOG TO MOST LOCATIONS ALONG AND EAST OF US HIGHWAY 85 LATE TONIGHT
INTO WEDNESDAY MORNING AS 60S F DEWPOINTS CONTINUE TO ADVECT
NORTH-NORTHWEST THIS EVENING. CERTAINLY CANNOT RULE OUT A
POTENTIAL DENSE FOG ADVISORY LATER TONIGHT GIVEN THE SIGNAL IN THE
HRRR.
UPDATE ISSUED AT 554 PM CDT TUE SEP 1 2015
DID ADD A MENTION OF FOG TO MUCH OF CENTRAL NORTH DAKOTA TONIGHT
AS 60S F DEWPOINTS CONTINUE TO ADVECT NORTH EARLY THIS
EVENING...WITH LIGHT WINDS AND CLEAR SKIES THROUGH THE OVERNIGHT.
THE 21 UTC HRRR AND 18 UTC NAM NEST SUPPORT THIS POTENTIAL VIA
THEIR REDUCED VISIBILITY FORECASTS ACROSS CENTRAL NORTH DAKOTA
LATE TONIGHT INTO EARLY WEDNESDAY MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 310 PM CDT TUE SEP 1 2015
THIS AFTERNOON...A WEAK SURFACE LOW PRESSURE TROUGH AND
ASSOCIATED WARM FRONT OVER CENTRAL SOUTH DAKOTA WAS A REFLECTION
OF A WEAKENING SHORT WAVE TROUGH ALOFT. THIS FEATURE IS FORECAST
TO MEANDER NORTHEAST WHILE DIMINISHING WITH TIME. SOUTHERLY LOW
LEVEL FLOW OVER THE WARM FRONT WILL TRANSFER MOISTURE NORTH INTO
THE JAMES RIVER VALLEY WHERE SEVERAL HIGH RESOLUTION MODELS AS
WELL AS THE GFS/NAM FORECAST SOME CONVECTION OVERNIGHT. WILL NEED
SOME TIME TO DEVELOP THIS SCENARIO SO DELAYED THE ONSET OF
CONVECTION UNTIL MIDNIGHT. OTHERWISE THIS FORCING WILL END/SHIFT
TO THE EAST ON WEDNESDAY. SKIES WILL BE MOSTLY SUNNY WEDNESDAY.
WITH A BROAD THERMAL RIDGE OVER EASTERN MONTANA AND NORTH DAKOTA
HIGHS WILL WARM WELL INTO THE 90S. HUMIDITY WILL BE LOW WITH
AFTERNOON VALUES REACHING 15 PERCENT WEST. THE MAJOR MISSING
COMPONENT WAS WINDS FOR FIRE WEATHER CONCERNS. WINDS WILL REMAIN
BELOW 15 MPH FOR THE MOST PART WEDNESDAY AFTERNOON.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 310 PM CDT TUE SEP 1 2015
CONTINUED VERY WARM WEDNESDAY INTO THURSDAY...FOLLOWED BY A
SIGNIFICANT PATTERN CHANGE FOR THE UPCOMING HOLIDAY WEEKEND.
STRONG UPPER LEVEL LOW DROPPING INTO THE PACIFIC NORTHWEST
WEDNESDAY WILL BECOME AN OPEN WAVE AND DEEPEN OVER THE WEST COAST
THROUGH SATURDAY. DURING THIS TIME NORTH DAKOTA WILL REMAIN ON THE
WESTERN EDGE OF THE UPSTREAM RIDGE AXIS...KEEPING VERY WARM AND
DRY AIR OVER THE STATE. HIGHS THURSDAY WILL ONCE AGAIN REACH INTO
THE 90S MANY LOCATIONS...WITH 80S NORTHWEST IN THE WAKE OF A SLOW
MOVING FRONTAL BOUNDARY. BY THURSDAY NIGHT EMBEDDED S/WV IMPULSES
WILL APPROACH THE REGION...AND WHEN COUPLED WITH THE BOUNDARY WILL
RESULT IN CHANCES FOR SHOWERS/THUNDERSTORMS WEST TO EAST DURING
THE NIGHT.
FRIDAY-SATURDAY THE WEST COAST UPPER TROUGH BEGINS TO MOVE FARTHER
INLAND AND WILL DIRECT A SERIES OF SHORTWAVE ENERGY IMPULSES ACROSS
THE NORTHERN PLAINS. THE EXPECTED INCREASE IN CLOUD COVER AND CAA
IN THE WAKE OF THE SFC FRONT WILL RESULT IN MUCH COOLER
TEMPERATURES...WITH HIGHS DROPPING INTO THE MID 60S NORTHWEST TO
LOW 80S OVER THE SOUTHERN JAMES RIVER VALLEY BY SATURDAY. SATURDAY
NIGHT INTO SUNDAY THE BASE OF THE TROUGH LIFTS NORTHEASTWARD INTO
THE NORTHERN PLAINS...REACHING SOUTHERN CANADA BY SUNDAY NIGHT.
THIS TIME PERIOD (FRIDAY-SUNDAY) WILL SEE VERY GOOD CHANCES FOR
SHOWERS AND THUNDERSTORMS.
A MORE ZONAL FLOW SETS UP EARLY NEXT WEEK AND SHOULD RESULT IN
MAINLY DRY CONDITIONS AND SOME TEMPERATURE RECOVERY AS WE PROGRESS
INTO THE MIDDLE PORTIONS OF THE WORK WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 939 PM CDT TUE SEP 1 2015
FOG IS FORECAST ACROSS MOST OF WESTERN AND CENTRAL NORTH DAKOTA
LATE TONIGHT INTO WEDNESDAY MORNING. KJMS AND KBIS ARE MOST LIKELY
TO BE IMPACTED...WITH IFR/LIFR VISIBILITY POSSIBLE. KMOT AND KDIK
MAY BE ON THE FRINGE OF THE POTENTIAL FOG BANK. ONCE FOG BURNS OFF
WEDNESDAY MORNING...VFR CONDITIONS ARE EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...WAA
LONG TERM...NH
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
653 PM CDT TUE SEP 1 2015
.UPDATE...
ISSUED AT 645 PM CDT TUE SEP 1 2015
NO CHANGES NEEDED THIS UPDATE PERIOD.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 325 PM CDT TUE SEP 1 2015
500 MB SHORT WAVE NOTED IN SOUTHEASTERN SOUTH DAKOTA MOVING
NORTHEAST. A BAND OF SHOWERS ARE WITH THIS SYSTEM. FOR TONIGHT
QUESTION IS PRECIP CHANCES OVERNIGHT INTO WED MORNING MAINLY FOR
NE ND INTO NW MN. FOR THE PAST COUPLE OF DAYS MODELS HAVE
INDICATED THREAT FOR SOME CONVECTION TO DEVELOP NR 06Z IN THE MID
RRV AND THE MOVE NORTHEAST THROUGH LAKE OF THE WOODS REGION BY
12Z. 12Z MODELS TODAY SHOW TO SOME DEGREE THE SAME THING...BUT
MORE GFS IN THIS CASE AS MOST SHORT RANGE MODELS SUCH AS THE HRRR
AND RAP DONT SHOW (AT LEAST WITH MIDDAY AND EARLY AFTN RUNS).
THERE IS AN IMPRESSIVE LOW-850 MB MOISTURE RETURN THIS EVENING-
OVERNIGHT. SEEING 70 DEW PTS ALONG THE SD/ND BORDER INTO THE
ALEXANDRIA AREA WHILE MOST OF OUR FCST AREA HAS DEW PTS IN THE
50S. SO WILL SEE A MOISTURE SURGE TONIGHT AND INSTABILITY INCREASE
IN THE 850 MB LAYER 06Z-12Z PERIOD WHEN A FEW HUNDRED 850 MB CAPE
AVAILABLE. PROBLEM IS LOW LEVEL JET IS VERY WEAK 20 KTS MAYBE. BUT
WILL SIDE WITH CONSISTENCY AND KEEP LOW POPS IN BUT HAVE THEM
06Z-12Z....EXTENDING THEM A FEW HOURS PAST 12Z IN LAKE OF THE
WOODS. WEDNESDAY WILL BE MUCH MORE HUMID AND WARM.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 325 PM CDT TUE SEP 1 2015
HOT AND HUMID ON THURSDAY WITH MID 80S EAST TO LOW 90S WEST. WILL
MAINTAIN A LOW THREAT FOR PRECIP LATE THURSDAY NIGHT IN ERN
ND...THEN KEEP CHC POPS ON FRIDAY. UNCERTAIN HOW EVENT WILL PLAY
OUT BUT WILL HAVE SEVERAL SHORT WAVES AND SFC LOWS MOVE NORTHEAST
ALONG A FRONTAL BOUNDARY WHICH WILL BE OVER OR NEAR OUR AREA. EACH
ONE GIVING GOOD CHANCES FOR SHOWERS AND THUNDERSTORMS STARTING
LATE FRIDAY. DAY TO DAY TIMING OF COURSE IS DIFFICULT AT THIS
STAGE.
SATURDAY TO TUESDAY...MODELS IN GOOD AGREEMENT WITH THE GENERAL
500MB SOUTHWEST FLOW ALOFT AND EVOLUTION WITH A CLOSED STRONG SHORT
WAVE MOVING OVER THE NORTHERN PLAINS EARLY NEXT WEEK. AS A RESULT AN
ACTIVE WEATHER PATTERN WITH SEVERAL ROUNDS OF CONVECTIVE ACTIVITY
CAN BE EXPECTED FOR THE REGION OVER THE HOLIDAY WEEKEND.
UNCERTAINTIES EXIST WITH THE TIMING AND PLACEMENT OF THE LEAD WAVE
AND THE STRONGER SHORT WAVE ON MONDAY. CURRENTLY A LEAD WAVE IS
EXPECTED TO BRING A ROUND OF THUNDERSTORMS FRIDAY NIGHT WITH ANOTHER
ROUND SATURDAY NIGHT BEFORE THE THE LIGHTER WRAP AROUND PCPN ON
SUNDAY AFTN AND EARLY MONDAY. GIVEN THE AMPLE MOISTURE IN
PLACE...PWATS APPROACHING 2 INCHES...HEAVY RAIN WILL BE POSSIBLE
WITH ANY STORM. TEMPERATURES WILL BE WARMEST ON SATURDAY WITH LOW
80S IN THE SE HALF OF THE FA AND 70S IN THE NW...HIGHLY INFLUENCED
BY EXPECTED CLOUD COVER. A COOLER...CLOSER TO AVERAGE TEMP REGIME IS
EXPECTED WITH 70S SUNDAY TO TUE BEHIND DEPARTING SHORT WAVE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 645 PM CDT TUE SEP 1 2015
MAIN CHALLENGE THIS PERIOD IS FOG AND T POTENTIAL LATER TONIGHT.
AS DEWPOINTS INCREASE TONIGHT SOME POTENTIAL FOR FOG DEVELOPMENT
ACROSS THE SOUTH. MIXING AND POTENTIAL MID CLOUD DEVELOPMENT MAY
LIMIT ANY FOG AS GUIDANCE NOT SHOWING ANY DEVELOPMENT. ALSO BAND
OF ENHANCED WARM ADVECTION MAY AID IN ISOLATED STORM DEVELOPMENT
WITH WEAK LOW LEVEL JET HOWEVER PLENTY OF CIN TO OVERCOME SO FOR
NOW HAVE LEFT BR AND T MENTION OUT OF TAFS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...VOELKER
SHORT TERM...RIDDLE
LONG TERM...JK/RIDDLE
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1237 PM CDT MON AUG 31 2015
.UPDATE...
ISSUED AT 1233 PM CDT MON AUG 31 2015
DROPPED ALL CHANCES FOR PRECIPITATION FOR THE REMAINDER OF TODAY.
ADDED HIGH CLOUDS TO THE SOUTH CENTRAL WHERE SKIES SHOULD BE
PARTLY SUNNY. SUNNY WEST AND NORTH.
UPDATE ISSUED AT 956 AM CDT MON AUG 31 2015
AT 9 PM CDT...A COLD FRONT WAS PROCEEDING THROUGH THE EASTERN
PORTION OF THE STATE. SKIES WERE CLEARING ACROSS THE WEST. BREEZY
CONDITIONS WILL SOON DEVELOP WEST. TRIMMED THE POPS BACK TO FOLLOW
THE FRONTAL BOUNDARY EAST. THE CHANCES FOR PRECIP WILL END BY
NOON. TEMPERATURES LOOK GOOD.
UPDATE ISSUED AT 632 AM CDT MON AUG 31 2015
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO LIFT
NORTHEAST ACROSS NORTHERN AND EASTERN NORTH DAKOTA. CONVECTION HAS
EXITED THE SOUTHWEST QUARTER OF THE STATE. MAIN UPDATE WAS TO POPS
BASED ON LATEST RADAR AND THE TIME LAGGED HRRR OUTPUT THROUGH THIS
MORNING. OTHERWISE NO SIGNIFICANT UPDATES NEEDED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT MON AUG 31 2015
SHOWERS AND THUNDERSTORMS ENDING BY NOON. THEN BREEZY WEST WINDS
BRING A DRIER AND COOLER AIRMASS INTO THE STATE.
A SURFACE COLD FRONT EXTENDED FROM AROUND LAKE WINNIPEG
SOUTHWESTWARD TO THE TURTLE MOUNTAIN AND DEVILS LAKE AREA...TO NEAR
BISMARCK TO THE BLACK HILLS AREA IN WESTERN SOUTH DAKOTA. SCATTERED
SHOWERS AND THUNDERSTORMS CONTINUED TO DEVELOP ALONG AND WEST OF THE
SURFACE FRONT...MOVING NORTHEASTWARD ALONG THE UPPER LEVEL FLOW. AT
UPPER LEVELS...A SERIES OF UPPER LEVEL IMPULSES WERE MOVING
NORTHEASTWARD FROM WYOMING INTO THE CENTRAL AND WESTERN DAKOTAS. A
STRONG UPPER LEVEL SHORTWAVE WAS FARTHER WEST OVER CENTRAL
MONTANA/SOUTHERN SASKATCHEWAN...AND IS FORECAST TO CONTINUE LIFTING
NORTHEASTWARD ACROSS NORTHWESTERN NORTH DAKOTA AND INTO SOUTHERN
MANITOBA.
THE SURFACE COLD FRONT IS FORECAST TO MOVE EAST...REACHING THE RED
RIVER VALLEY AREA AROUND NOON. THE SHOWERS AND THUNDERSTORMS SHOULD
BE ENDING IN THE SOUTHWEST EARLY THIS MORNING...AND ENDING BY EARLY
AFTERNOON IN THE FAR NORTH AND JAMES RIVER VALLEY. THIS SHOULD OCCUR
AS THE LAST OF THE UPPER LEVEL IMPULSES AND STRONG SHORTWAVE MOVE
EAST OUT OF WESTERN AND CENTRAL NORTH DAKOTA.
A SECONDARY SURGE OF COOLER AND DRIER AIR WELL BEHIND THE FRONT
IS PROGGED TO PUSH INTO FAR WESTERN NORTH DAKOTA BEFORE DAYBREAK
THIS MORNING...WITH H850 WINDS OF 25 TO 35 KNOTS AT THE LEADING EDGE
OF THE AIRMASS. THIS IS DRY AIR MOVING ACROSS THE ROCKIES AND INTO
THE FRONT RANGE. CURRENT DEWPOINT TEMPERATURES IN THE WEST WERE IN
THE 50S WITH 60S IN THE EASTERN HALF OF THE STATE. THIS AFTERNOON
THE DEWPOINTS SHOULD BE AS LOW AS THE LOW TO MID 30S IN WESTERN
NORTH DAKOTA...AND IN THE 40S AND 50S EAST. HIGHS IN THE UPPER 70S
WEST WILL RESULT IN AFTERNOON MINIMUM RELATIVE HUMIDITY VALUES
AROUND 20 PERCENT. WEST WINDS OF 20 TO 25 MPH WITH GUSTS TO 30 MPH
CAN BE EXPECTED LATER THIS MORNING...BUT SHOULD DIMINISH SOMEWHAT
THIS AFTERNOON AFTER THE INITIAL PUSH OF DRY AIR. THUS THE STRONGEST
WINDS TODAY SHOULD NOT COINCIDE WITH THE LOWEST RELATIVE HUMIDITY
VALUES...AND RED FLAG CRITERIA ARE NOT EXPECTED TO BE MET.
LOOK FOR BREEZY WEST WINDS TO DEVELOP TODAY WITH DECREASING CLOUDS
FROM SOUTHWEST TO NORTHEAST. HIGHS SHOULD RANGE FROM THE UPPER 70S
NORTH AND WEST TO THE LOW TO MID 80S SOUTH CENTRAL.
DECREASING WINDS THIS EVENING WITH CLEAR SKIES. LOWS SHOULD BE
MAINLY IN THE 50S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 335 AM CDT MON AUG 31 2015
CONTINUED WARM TEMPERATURES AND SLIGHT/PERIODIC THUNDERSTORM CHANCES
WILL HIGHLIGHT THE EXTENDED FORECAST PERIOD THROUGH THE WORK WEEK.
MODEL DIFFERENCES APPEAR BY THE WEEKEND WITH A POSSIBLE PATTERN
CHANGE INTO THE EARLY PORTIONS OF NEXT WEEK.
ON TUESDAY...MAINTAINED A SLIGHT CHANCE OF MAINLY EVENING AND
OVERNIGHT THUNDERSTORMS FOR THE DEVILS LAKE BASIN AND JAMES RIVER
VALLEY WITH MODELS STILL SHOWING INCREASING INSTABILITY WITH DAYTIME
HEATING COUPLED WITH AN INCREASING LOW LEVEL JET ACROSS THE EASTERN
HALF OF THE STATE. CAPPING DURING THE DAY MAY HOLD OFF ON CONVECTION
UNTIL AFTER 00Z.
BEYOND TUESDAY...OUR SOUTHWEST UPPER FLOW WILL CONTINUE THROUGH THE
END OF THE WORK WEEK WITH TROUGHING ACROSS THE PACIFIC NORTHWEST AND
RIDGING OFF TO OUR EAST. A QUASI-STATIONARY SURFACE TROUGH COMBINED
WITH ANY EMBEDDED WAVES ALOFT WILL PROVIDE A FOCUS FOR MAINLY
ISOLATED DAILY SHOWER AND THUNDERSTORM ACTIVITY. BEST CHANCES APPEAR
TO BE TOWARDS THE END OF THE WORK WEEK AND INTO NEXT WEEKEND WHEN A
STRONG UPPER JET APPROACHES THE NORTHERN PLAINS. TEMPERATURES WILL
REMAIN NEAR TO SLIGHTLY ABOVE NORMAL THROUGH THE WORK WEEK.
DISAGREEMENT IN DETERMINISTIC MODELS CROPS UP BY THE WEEKEND
REGARDING THE STRONG UPPER LEVEL TROUGH TO OUR WEST. THE 00 UTC 31
AUG GFS IS NOW MUCH MORE PROGRESSIVE AND WEAKER WITH THIS FEATURE.
THUS COOLER CONDITIONS ENTER THE NORTHERN PLAINS SATURDAY AND SUNDAY
WITH A WARM-UP RETURNING BY THE BEGINNING OF NEXT WEEK. THE ECMWF
IS MUCH SLOWER AND STRONGER...KEEPING IT MILD THROUGH THE FIRST
HALF OF THE WEEKEND...THEN COOLING SUNDAY INTO EARLY NEXT WEEK AND
WITH MUCH COLDER TEMPERATURES OVER THE AREA EARLY NEXT WEEK. THE
GLOBAL GEM WAS ALSO SHOWING A SLOWER SOLUTION THAN THE GFS THROUGH
SUNDAY. THE GFSENSEMBLE SPREAD WAS MUCH GREATER LATE IN THE
WEEKEND COMPARED TO THE ECMWF ENSEMBLE...THUS MAYBE AN INDICATION
THAT THE SLOWER SOLUTION WILL PREVAIL. BUT FOR NOW WILL HOLD
STEADY WITH OUR CURRENT MODEL BLEND SOLUTION WHICH IS STILL
TRENDING COOLER FOR THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1233 PM CDT MON AUG 31 2015
AT NOON CDT A COLD FRONT WAS PROGRESSING THROUGH EASTERN NORTH
DAKOTA WITH HIGH PRESSURE BUILDING INTO MONTANA. VFR EXPECTED
THROUGH TEH 18ZTAF PERIOD,.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...JV
LONG TERM...TWH
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1000 AM CDT MON AUG 31 2015
.UPDATE...
ISSUED AT 956 AM CDT MON AUG 31 2015
AT 9 PM CDT...A COLD FRONT WAS PROCEEDING THROUGH THE EASTERN
PORTION OF THE STATE. SKIES WERE CLEARING ACROSS THE WEST. BREEZY
CONDITIONS WILL SOON DEVELOP WEST. TRIMMED THE POPS BACK TO FOLLOW
THE FRONTAL BOUNDARY EAST. THE CHANCES FOR PRECIP WILL END BY
NOON. TEMPERATURES LOOK GOOD.
UPDATE ISSUED AT 632 AM CDT MON AUG 31 2015
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO LIFT
NORTHEAST ACROSS NORTHERN AND EASTERN NORTH DAKOTA. CONVECTION HAS
EXITED THE SOUTHWEST QUARTER OF THE STATE. MAIN UPDATE WAS TO POPS
BASED ON LATEST RADAR AND THE TIME LAGGED HRRR OUTPUT THROUGH THIS
MORNING. OTHERWISE NO SIGNIFICANT UPDATES NEEDED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT MON AUG 31 2015
SHOWERS AND THUNDERSTORMS ENDING BY NOON. THEN BREEZY WEST WINDS
BRING A DRIER AND COOLER AIRMASS INTO THE STATE.
A SURFACE COLD FRONT EXTENDED FROM AROUND LAKE WINNIPEG
SOUTHWESTWARD TO THE TURTLE MOUNTAIN AND DEVILS LAKE AREA...TO NEAR
BISMARCK TO THE BLACK HILLS AREA IN WESTERN SOUTH DAKOTA. SCATTERED
SHOWERS AND THUNDERSTORMS CONTINUED TO DEVELOP ALONG AND WEST OF THE
SURFACE FRONT...MOVING NORTHEASTWARD ALONG THE UPPER LEVEL FLOW. AT
UPPER LEVELS...A SERIES OF UPPER LEVEL IMPULSES WERE MOVING
NORTHEASTWARD FROM WYOMING INTO THE CENTRAL AND WESTERN DAKOTAS. A
STRONG UPPER LEVEL SHORTWAVE WAS FARTHER WEST OVER CENTRAL
MONTANA/SOUTHERN SASKATCHEWAN...AND IS FORECAST TO CONTINUE LIFTING
NORTHEASTWARD ACROSS NORTHWESTERN NORTH DAKOTA AND INTO SOUTHERN
MANITOBA.
THE SURFACE COLD FRONT IS FORECAST TO MOVE EAST...REACHING THE RED
RIVER VALLEY AREA AROUND NOON. THE SHOWERS AND THUNDERSTORMS SHOULD
BE ENDING IN THE SOUTHWEST EARLY THIS MORNING...AND ENDING BY EARLY
AFTERNOON IN THE FAR NORTH AND JAMES RIVER VALLEY. THIS SHOULD OCCUR
AS THE LAST OF THE UPPER LEVEL IMPULSES AND STRONG SHORTWAVE MOVE
EAST OUT OF WESTERN AND CENTRAL NORTH DAKOTA.
A SECONDARY SURGE OF COOLER AND DRIER AIR WELL BEHIND THE FRONT
IS PROGGED TO PUSH INTO FAR WESTERN NORTH DAKOTA BEFORE DAYBREAK
THIS MORNING...WITH H850 WINDS OF 25 TO 35 KNOTS AT THE LEADING EDGE
OF THE AIRMASS. THIS IS DRY AIR MOVING ACROSS THE ROCKIES AND INTO
THE FRONT RANGE. CURRENT DEWPOINT TEMPERATURES IN THE WEST WERE IN
THE 50S WITH 60S IN THE EASTERN HALF OF THE STATE. THIS AFTERNOON
THE DEWPOINTS SHOULD BE AS LOW AS THE LOW TO MID 30S IN WESTERN
NORTH DAKOTA...AND IN THE 40S AND 50S EAST. HIGHS IN THE UPPER 70S
WEST WILL RESULT IN AFTERNOON MINIMUM RELATIVE HUMIDITY VALUES
AROUND 20 PERCENT. WEST WINDS OF 20 TO 25 MPH WITH GUSTS TO 30 MPH
CAN BE EXPECTED LATER THIS MORNING...BUT SHOULD DIMINISH SOMEWHAT
THIS AFTERNOON AFTER THE INITIAL PUSH OF DRY AIR. THUS THE STRONGEST
WINDS TODAY SHOULD NOT COINCIDE WITH THE LOWEST RELATIVE HUMIDITY
VALUES...AND RED FLAG CRITERIA ARE NOT EXPECTED TO BE MET.
LOOK FOR BREEZY WEST WINDS TO DEVELOP TODAY WITH DECREASING CLOUDS
FROM SOUTHWEST TO NORTHEAST. HIGHS SHOULD RANGE FROM THE UPPER 70S
NORTH AND WEST TO THE LOW TO MID 80S SOUTH CENTRAL.
DECREASING WINDS THIS EVENING WITH CLEAR SKIES. LOWS SHOULD BE
MAINLY IN THE 50S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 335 AM CDT MON AUG 31 2015
CONTINUED WARM TEMPERATURES AND SLIGHT/PERIODIC THUNDERSTORM CHANCES
WILL HIGHLIGHT THE EXTENDED FORECAST PERIOD THROUGH THE WORK WEEK.
MODEL DIFFERENCES APPEAR BY THE WEEKEND WITH A POSSIBLE PATTERN
CHANGE INTO THE EARLY PORTIONS OF NEXT WEEK.
ON TUESDAY...MAINTAINED A SLIGHT CHANCE OF MAINLY EVENING AND
OVERNIGHT THUNDERSTORMS FOR THE DEVILS LAKE BASIN AND JAMES RIVER
VALLEY WITH MODELS STILL SHOWING INCREASING INSTABILITY WITH DAYTIME
HEATING COUPLED WITH AN INCREASING LOW LEVEL JET ACROSS THE EASTERN
HALF OF THE STATE. CAPPING DURING THE DAY MAY HOLD OFF ON CONVECTION
UNTIL AFTER 00Z.
BEYOND TUESDAY...OUR SOUTHWEST UPPER FLOW WILL CONTINUE THROUGH THE
END OF THE WORK WEEK WITH TROUGHING ACROSS THE PACIFIC NORTHWEST AND
RIDGING OFF TO OUR EAST. A QUASI-STATIONARY SURFACE TROUGH COMBINED
WITH ANY EMBEDDED WAVES ALOFT WILL PROVIDE A FOCUS FOR MAINLY
ISOLATED DAILY SHOWER AND THUNDERSTORM ACTIVITY. BEST CHANCES APPEAR
TO BE TOWARDS THE END OF THE WORK WEEK AND INTO NEXT WEEKEND WHEN A
STRONG UPPER JET APPROACHES THE NORTHERN PLAINS. TEMPERATURES WILL
REMAIN NEAR TO SLIGHTLY ABOVE NORMAL THROUGH THE WORK WEEK.
DISAGREEMENT IN DETERMINISTIC MODELS CROPS UP BY THE WEEKEND
REGARDING THE STRONG UPPER LEVEL TROUGH TO OUR WEST. THE 00 UTC 31
AUG GFS IS NOW MUCH MORE PROGRESSIVE AND WEAKER WITH THIS FEATURE.
THUS COOLER CONDITIONS ENTER THE NORTHERN PLAINS SATURDAY AND SUNDAY
WITH A WARM-UP RETURNING BY THE BEGINNING OF NEXT WEEK. THE ECMWF
IS MUCH SLOWER AND STRONGER...KEEPING IT MILD THROUGH THE FIRST
HALF OF THE WEEKEND...THEN COOLING SUNDAY INTO EARLY NEXT WEEK AND
WITH MUCH COLDER TEMPERATURES OVER THE AREA EARLY NEXT WEEK. THE
GLOBAL GEM WAS ALSO SHOWING A SLOWER SOLUTION THAN THE GFS THROUGH
SUNDAY. THE GFSENSEMBLE SPREAD WAS MUCH GREATER LATE IN THE
WEEKEND COMPARED TO THE ECMWF ENSEMBLE...THUS MAYBE AN INDICATION
THAT THE SLOWER SOLUTION WILL PREVAIL. BUT FOR NOW WILL HOLD
STEADY WITH OUR CURRENT MODEL BLEND SOLUTION WHICH IS STILL
TRENDING COOLER FOR THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 632 AM CDT MON AUG 31 2015
SCATTERED THUNDERSTORMS ARE POSSIBLE AT KISN/KMOT/KJMS THIS MORNING.
THOUGH NOT OUT OF THE QUESTION...IT APPEARS THAT THE THUNDERSTORM
THREAT AT KDIK AND KBIS HAS PASSED. A COLD FRONT EXTENDED FROM NEAR
DEVILS LAKE TO NEAR STEELE TO LINTON...TO NEAR MOBRIDGE IN SOUTH
DAKOTA. COOLER AND DRIER AIR WAS PUSHING INTO THE WESTERN PART OF
NORTH DAKOTA. NORTHWEST WINDS HAD JUST BEGUN TO INCREASE AT CROSBY.
INCREASE OF NORTHWEST WINDS SHOULD SPREAD FROM NORTHWEST TO
SOUTHEAST AT TAF SITES...BEGINNING AT KISN SOON AFTER 12Z AND
REACHING KJMS BY AROUND 18Z. DECREASING WINDS AFT 00Z.
SMOKE MAY BECOME MORE WIDESPREAD AND THICKER THROUGH THE
DAY...BUT NOT CONFIDENT REGARDING AFFECTS AT THE SURFACE AT MOST TAF
SITES. MENTIONED VSBY REDUCTION AT KBIS WITH 4SM REPORTED AT 6 AM
CDT BECAUSE OF SMOKE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...JV
LONG TERM...TWH
AVIATION...JV
AREA FORECAST DISCUSSION
NWS BISMARCK ND
637 AM CDT MON AUG 31 2015
.UPDATE...
ISSUED AT 632 AM CDT MON AUG 31 2015
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO LIFT
NORTHEAST ACROSS NORTHERN AND EASTERN NORTH DAKOTA. CONVECTION HAS
EXITED THE SOUTHWEST QUARTER OF THE STATE. MAIN UPDATE WAS TO POPS
BASED ON LATEST RADAR AND THE TIME LAGGED HRRR OUTPUT THROUGH THIS
MORNING. OTHERWISE NO SIGNIFICANT UPDATES NEEDED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT MON AUG 31 2015
SHOWERS AND THUNDERSTORMS ENDING BY NOON. THEN BREEZY WEST WINDS
BRING A DRIER AND COOLER AIRMASS INTO THE STATE.
A SURFACE COLD FRONT EXTENDED FROM AROUND LAKE WINNIPEG
SOUTHWESTWARD TO THE TURTLE MOUNTAIN AND DEVILS LAKE AREA...TO NEAR
BISMARCK TO THE BLACK HILLS AREA IN WESTERN SOUTH DAKOTA. SCATTERED
SHOWERS AND THUNDERSTORMS CONTINUED TO DEVELOP ALONG AND WEST OF THE
SURFACE FRONT...MOVING NORTHEASTWARD ALONG THE UPPER LEVEL FLOW. AT
UPPER LEVELS...A SERIES OF UPPER LEVEL IMPULSES WERE MOVING
NORTHEASTWARD FROM WYOMING INTO THE CENTRAL AND WESTERN DAKOTAS. A
STRONG UPPER LEVEL SHORTWAVE WAS FARTHER WEST OVER CENTRAL
MONTANA/SOUTHERN SASKATCHEWAN...AND IS FORECAST TO CONTINUE LIFTING
NORTHEASTWARD ACROSS NORTHWESTERN NORTH DAKOTA AND INTO SOUTHERN
MANITOBA.
THE SURFACE COLD FRONT IS FORECAST TO MOVE EAST...REACHING THE RED
RIVER VALLEY AREA AROUND NOON. THE SHOWERS AND THUNDERSTORMS SHOULD
BE ENDING IN THE SOUTHWEST EARLY THIS MORNING...AND ENDING BY EARLY
AFTERNOON IN THE FAR NORTH AND JAMES RIVER VALLEY. THIS SHOULD OCCUR
AS THE LAST OF THE UPPER LEVEL IMPULSES AND STRONG SHORTWAVE MOVE
EAST OUT OF WESTERN AND CENTRAL NORTH DAKOTA.
A SECONDARY SURGE OF COOLER AND DRIER AIR WELL BEHIND THE FRONT
IS PROGGED TO PUSH INTO FAR WESTERN NORTH DAKOTA BEFORE DAYBREAK
THIS MORNING...WITH H850 WINDS OF 25 TO 35 KNOTS AT THE LEADING EDGE
OF THE AIRMASS. THIS IS DRY AIR MOVING ACROSS THE ROCKIES AND INTO
THE FRONT RANGE. CURRENT DEWPOINT TEMPERATURES IN THE WEST WERE IN
THE 50S WITH 60S IN THE EASTERN HALF OF THE STATE. THIS AFTERNOON
THE DEWPOINTS SHOULD BE AS LOW AS THE LOW TO MID 30S IN WESTERN
NORTH DAKOTA...AND IN THE 40S AND 50S EAST. HIGHS IN THE UPPER 70S
WEST WILL RESULT IN AFTERNOON MINIMUM RELATIVE HUMIDITY VALUES
AROUND 20 PERCENT. WEST WINDS OF 20 TO 25 MPH WITH GUSTS TO 30 MPH
CAN BE EXPECTED LATER THIS MORNING...BUT SHOULD DIMINISH SOMEWHAT
THIS AFTERNOON AFTER THE INITIAL PUSH OF DRY AIR. THUS THE STRONGEST
WINDS TODAY SHOULD NOT COINCIDE WITH THE LOWEST RELATIVE HUMIDITY
VALUES...AND RED FLAG CRITERIA ARE NOT EXPECTED TO BE MET.
LOOK FOR BREEZY WEST WINDS TO DEVELOP TODAY WITH DECREASING CLOUDS
FROM SOUTHWEST TO NORTHEAST. HIGHS SHOULD RANGE FROM THE UPPER 70S
NORTH AND WEST TO THE LOW TO MID 80S SOUTH CENTRAL.
DECREASING WINDS THIS EVENING WITH CLEAR SKIES. LOWS SHOULD BE
MAINLY IN THE 50S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 335 AM CDT MON AUG 31 2015
CONTINUED WARM TEMPERATURES AND SLIGHT/PERIODIC THUNDERSTORM CHANCES
WILL HIGHLIGHT THE EXTENDED FORECAST PERIOD THROUGH THE WORK WEEK.
MODEL DIFFERENCES APPEAR BY THE WEEKEND WITH A POSSIBLE PATTERN
CHANGE INTO THE EARLY PORTIONS OF NEXT WEEK.
ON TUESDAY...MAINTAINED A SLIGHT CHANCE OF MAINLY EVENING AND
OVERNIGHT THUNDERSTORMS FOR THE DEVILS LAKE BASIN AND JAMES RIVER
VALLEY WITH MODELS STILL SHOWING INCREASING INSTABILITY WITH DAYTIME
HEATING COUPLED WITH AN INCREASING LOW LEVEL JET ACROSS THE EASTERN
HALF OF THE STATE. CAPPING DURING THE DAY MAY HOLD OFF ON CONVECTION
UNTIL AFTER 00Z.
BEYOND TUESDAY...OUR SOUTHWEST UPPER FLOW WILL CONTINUE THROUGH THE
END OF THE WORK WEEK WITH TROUGHING ACROSS THE PACIFIC NORTHWEST AND
RIDGING OFF TO OUR EAST. A QUASI-STATIONARY SURFACE TROUGH COMBINED
WITH ANY EMBEDDED WAVES ALOFT WILL PROVIDE A FOCUS FOR MAINLY
ISOLATED DAILY SHOWER AND THUNDERSTORM ACTIVITY. BEST CHANCES APPEAR
TO BE TOWARDS THE END OF THE WORK WEEK AND INTO NEXT WEEKEND WHEN A
STRONG UPPER JET APPROACHES THE NORTHERN PLAINS. TEMPERATURES WILL
REMAIN NEAR TO SLIGHTLY ABOVE NORMAL THROUGH THE WORK WEEK.
DISAGREEMENT IN DETERMINISTIC MODELS CROPS UP BY THE WEEKEND
REGARDING THE STRONG UPPER LEVEL TROUGH TO OUR WEST. THE 00 UTC 31
AUG GFS IS NOW MUCH MORE PROGRESSIVE AND WEAKER WITH THIS FEATURE.
THUS COOLER CONDITIONS ENTER THE NORTHERN PLAINS SATURDAY AND SUNDAY
WITH A WARM-UP RETURNING BY THE BEGINNING OF NEXT WEEK. THE ECMWF
IS MUCH SLOWER AND STRONGER...KEEPING IT MILD THROUGH THE FIRST
HALF OF THE WEEKEND...THEN COOLING SUNDAY INTO EARLY NEXT WEEK AND
WITH MUCH COLDER TEMPERATURES OVER THE AREA EARLY NEXT WEEK. THE
GLOBAL GEM WAS ALSO SHOWING A SLOWER SOLUTION THAN THE GFS THROUGH
SUNDAY. THE GFSENSEMBLE SPREAD WAS MUCH GREATER LATE IN THE
WEEKEND COMPARED TO THE ECMWF ENSEMBLE...THUS MAYBE AN INDICATION
THAT THE SLOWER SOLUTION WILL PREVAIL. BUT FOR NOW WILL HOLD
STEADY WITH OUR CURRENT MODEL BLEND SOLUTION WHICH IS STILL
TRENDING COOLER FOR THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 632 AM CDT MON AUG 31 2015
SCATTERED THUNDERSTORMS ARE POSSIBLE AT KISN/KMOT/KJMS THIS MORNING.
THOUGH NOT OUT OF THE QUESTION...IT APPEARS THAT THE THUNDERSTORM
THREAT AT KDIK AND KBIS HAS PASSED. A COLD FRONT EXTENDED FROM NEAR
DEVILS LAKE TO NEAR STEELE TO LINTON...TO NEAR MOBRIDGE IN SOUTH
DAKOTA. COOLER AND DRIER AIR WAS PUSHING INTO THE WESTERN PART OF
NORTH DAKOTA. NORTHWEST WINDS HAD JUST BEGUN TO INCREASE AT CROSBY.
INCREASE OF NORTHWEST WINDS SHOULD SPREAD FROM NORTHWEST TO
SOUTHEAST AT TAF SITES...BEGINNING AT KISN SOON AFTER 12Z AND
REACHING KJMS BY AROUND 18Z. DECREASING WINDS AFT 00Z.
SMOKE MAY BECOME MORE WIDESPREAD AND THICKER THROUGH THE
DAY...BUT NOT CONFIDENT REGARDING AFFECTS AT THE SURFACE AT MOST TAF
SITES. MENTIONED VSBY REDUCTION AT KBIS WITH 4SM REPORTED AT 6 AM
CDT BECAUSE OF SMOKE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...JV
LONG TERM...TWH
AVIATION...JV
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1244 AM CDT MON AUG 31 2015
.UPDATE...
ISSUED AT 1244 AM CDT MON AUG 31 2015
CONVECTION HAS DEVELOPED RAPIDLY OVER WESTERN NORTH DAKOTA THE PAST
COUPLE OF HOURS. THE UPPER LEVEL SHORTWAVES MOVING NORTHEAST THROUGH
THE SOUTHWEST FLOW ALOFT WERE FORECAST BY THE SHORT TERM MODELS TO
MOVE INTO WESTERN NORTH DAKOTA BETWEEN 10 PM AND 1 AM CDT. SHOWERS
AND THUNDERSTORMS SHOULD CONTINUE OVERNIGHT ACROSS WESTERN NORTH
DAKOTA AND MOVE INTO THE MINOT/BISMARCK AREA BY 2-3 AM CDT...AND
INTO JAMESTOWN BEFORE SUNRISE. STORMS SHOULD BE SCATTERED IN
NATURE. SOME STORMS WERE ON THE STRONGER SIDE IN EASTERN
MONTANA...BUT AS THEY APPROACH THE MID-LEVEL THERMAL RIDGE AXIS OVER
CENTRAL NORTH DAKOTA...IT APPEARS THE STORMS WEAKEN A BIT.
ALSO...THE MORE NUMEROUS THE STORMS THE MORE SPREAD OUT THE
AVAILABLE ENERGY USE BECOMES...THUS DO NOT EXPECT SEVERE STORMS
THIS MORNING. NO SIGNIFICANT CHANGE IN THE OVERALL FORECAST THIS
UPDATE.
UPDATE ISSUED AT 946 PM CDT SUN AUG 30 2015
NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE...WITH A TIME
LAGGED ENSEMBLE OF THE 23-01 UTC HRRR ITERATIONS AND THE 00 UTC
NAM NEST STILL HANDLING WELL THE ONGOING POST-FRONTAL CONVECTION
ACROSS EASTERN MONTANA AND INTO SOUTHWEST NORTH DAKOTA.
THUS...WILL FOLLOW THEIR SOLUTIONS FOR POPS THE REMAINDER OF THE
NIGHT.
UPDATE ISSUED AT 627 PM CDT SUN AUG 30 2015
AS OF 2330 UTC...A COLD FRONT WAS PROPAGATING ACROSS THE HIGHWAY
83 CORRIDOR...AND WILL CONTINUE ITS EASTWARD PROGRESSION THROUGH
THE EVENING. THEREAFTER...POST-FRONTAL CONVECTION IS EXPECTED TO
ENTER SOUTHWEST NORTH DAKOTA AROUND 05 UTC AND SPREAD NORTHEAST
THROUGH THE NIGHT. THIS IS IN ASSOCIATION WITH MULTIPLE IMPULSES
EMBEDDED IN SOUTHWEST FLOW ALOFT AHEAD OF THE STRONGER NORTHERN
US ROCKIES SHORTWAVE. GIVEN GOOD HANDLING OF ONGOING CONVECTION
THROUGH 23 UTC...USED A BLEND THE 20-22 UTC HRRR TIME LAGGED
ENSEMBLE AND 18 UTC NAM NEST.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 345 PM CDT SUN AUG 30 2015
COLD FRONT ACROSS NORTHWEST NORTH DAKOTA SUNDAY AFTERNOON IS
NEARLY ALIGNED WITH THE FLOW ALOFT AND THUS IS MOVING SLOWLY
EAST. IT APPEARS SOME SMOKE IS POOLING ALONG THE FRONTAL BOUNDARY
AND IMPACTING NORTHWEST NORTH DAKOTA WITH WILLISTON AROUND 2 MILES
IN HAZE/SMOKE SO FAR THIS AFTERNOON. WILL ADD A PERIOD OF SMOKEY
WEATHER FOR NORTHWEST NORTH DAKOTA THROUGH THE MID EVENING.
OTHERWISE WILL NOT MENTION MORE SMOKE TONIGHT. SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS WILL FOLLOW THE FRONT AS IT PROGRESSES
SLOWLY ACROSS THE STATE TONIGHT. KEPT POPS ON THE LOW SIDE WITH
NOT MUCH MORE THAN 30 PERCENT POPS TONIGHT ENDING MONDAY MORNING.
COOLER MONDAY WITH HIGHS IN THE MID 70S TO LOWER 80S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 345 PM CDT SUN AUG 30 2015
CONTINUED WARM TEMPERATURES AND SLIGHT/PERIODIC THUNDERSTORM
CHANCES WILL HIGHLIGHT THE EXTENDED FORECAST PERIOD NEXT WEEK.
A SIGNIFICANT PATTERN CHANGE IS THEN DEPICTED FOR LATE NEXT
WEEKEND INTO THE EARLY PORTIONS OF THE FOLLOWING WORK WEEK.
ON TUESDAY...MAINTAINED A SLIGHT CHANCE OF MAINLY EVENING AND
OVERNIGHT THUNDERSTORMS FOR THE DEVILS LAKE BASIN AND JAMES RIVER
VALLEY WITH MODELS STILL SHOWING INCREASING INSTABILITY WITH
DAYTIME HEATING COUPLED WITH AN INCREASING LOW LEVEL JET ACROSS
THE EASTERN HALF OF THE STATE. CAPPING DURING THE DAY MAY HOLD
OFF ON CONVECTION UNTIL AFTER 00Z.
BEYOND TUESDAY...OUR SOUTHWEST UPPER FLOW WILL CONTINUE THROUGH THE
END OF THE EXTENDED PERIOD WITH TROUGHING ACROSS THE PACIFIC
NORTHWEST AND RIDGING OFF TO OUR EAST. A QUASI-STATIONARY SURFACE
TROUGH COMBINED WITH ANY EMBEDDED WAVES ALOFT WILL PROVIDE A FOCUS
FOR MAINLY ISOLATED DAILY SHOWER AND THUNDERSTORM ACTIVITY. BEST
CHANCES APPEAR TO BE TOWARDS THE END OF THE WORK WEEK AND INTO
NEXT WEEKEND WHEN A STRONG UPPER JET APPROACHES THE NORTHERN
PLAINS. TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY ABOVE NORMAL
THROUGH THE WORK WEEK WITH 80S TO LOW 90S FOR HIGHS THEN COOLING A
BIT INTO THE 70S AND 80S BY NEXT WEEKEND.
BOTH THE 12Z GFS/ECMWF THEN BRING A STRONG COLD FRONT THROUGH THE
REGION LATE NEXT WEEKEND OR EARLY NEXT WEEK. BOTH MODELS INDICATE
THE POTENTIAL FOR A SIGNIFICANT COOL DOWN WITH 850MB TEMPERATURES
3-5C DEGREES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1244 AM CDT MON AUG 31 2015
SCATTERED THUNDERSTORMS ARE EXPECTED TO CONTINUE TO DEVELOP OVER
WESTERN NORTH DAKOTA AND SPREAD EAST/NORTHEAST OVERNIGHT. THE
CONVECTION WAS MAINLY ALONG AND BEHIND THE COLD FRONT...WHICH
EXTENDED FROM NEAR KDVL TO NEAR KBIS...TO THE BORDER OF MT/WY/SD.
THE FRONT IS FORECAST TO MOVE EAST INTO THE JAMES VALLEY BY 12Z AND
REACHING THE RED RIVER VALLEY AROUND 18Z. THUNDERSTORM CHANCES
ENDING AT KISN/KDIK AROUND 12Z...ENDING AT KMOT/KBIS BY AROUND
15Z...AND ENDING AT KJMS BY AROUND 18Z. GUSTY WEST WINDS BEHIND THE
FRONT. SMOKE MAY BECOME MORE WIDESPREAD AND THICKER THROUGH THE DAY
MONDAY...BUT NOT CONFIDENT REGARDING AFFECTS AT THE SURFACE AND LEFT
MENTION OUT OF THE TAFS THIS PACKAGE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...WAA
LONG TERM...NH
AVIATION...JV
AREA FORECAST DISCUSSION
NWS NORMAN OK
326 PM CDT MON AUG 31 2015
.DISCUSSION...
A WEAK UPPER LOW CONTINUES TO SPIN ACROSS SOUTHEAST OKLAHOMA.
ALTHOUGH LATEST RAP & HRRR RUNS KEEP IT INACTIVE THERE, WATER
VAPOR IMAGERY CONTINUES TO SHOW A SLIGHT MIDLEVEL CIRCULATION,
ENOUGH TO MAINTAIN LOW TSRA POPS THERE UNTIL THIS EVENING.
OTHERWISE, AN UPPER RIDGE IS EXPECTED TO BUILD THROUGH MUCH OF THE
WEEK, KEEPING US DRY AND MAINTAINING SEASONABLY NORMAL
TEMPERATURES. HOWEVER, THE ECMWF SOLUTION SUGGEST A SHORT WAVE
DISTURBANCE DIGGING ACROSS FAR NORTHWEST OKLAHOMA FOR THURSDAY
NIGHT. FOR NOW, WILL BE KEEPING ANY POPS OUT OF THERE, MAINLY DUE
TO UNCERTAINTY OF MOISTURE AVAILABILITY.
A MUCH DEEPER TROUGH WILL BE DIGGING ACROSS THE NORTHERN U.S.
DURING THE WEEKEND, WHICH WILL BE PUSHING A COLD FRONT INTO OUR
AREA BEGINNING FOR MONDAY. AT THIS POINT, BOTH LONG RANGE MODELS
HINT A PACIFIC BASED MIDLEVEL MOISTURE PLUME, ORIGINATING FROM THE
GULF OF CALIFORNIA, EXTENDING INTO NORTHWEST OKLAHOMA BEGINNING
SUNDAY. WITH THE COLD FRONT APPROACHING NEAR THE TIME PERIOD, IT
WOULD CERTAINLY NOT RULE OUT LOW TSRA POPS IN OUR NORTHWEST FOR
THE SUNDAY THROUGH MONDAY TIME FRAME.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 71 92 70 92 / 0 0 0 0
HOBART OK 70 95 71 95 / 0 0 0 0
WICHITA FALLS TX 72 95 71 95 / 0 0 0 0
GAGE OK 69 94 70 94 / 0 0 10 0
PONCA CITY OK 71 93 70 92 / 0 0 0 0
DURANT OK 71 94 71 94 / 10 10 10 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
17/67
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
1240 AM CDT MON AUG 31 2015
.DISCUSSION...
31/06Z TAF DISCUSSION BELOW.
&&
.AVIATION...
WILL MENTION MVFR BR AT KPNC THROUGH 15Z WITH SOME DENSE FOG NOT
OUT OF THE REALM OF POSSIBILITIES. OTHERWISE...VFR CONDITIONS
EXPECTED THROUGH PERIOD WITH RETURN TO SOUTHERLY WINDS.
&&
.PREV DISCUSSION... /ISSUED 927 PM CDT SUN AUG 30 2015/
UPDATE...
RAIN HAS ENDED ACROSS THE FA. THE REST OF THE NIGHT IS EXPECTED
TO REMAIN DRY BUT IT IS NOT COMPLETELY OUT OF THE QUESTION THAT A
FEW MORE ISOLATED SHOWERS/STORMS MAY DEVELOP IN SE PARTS OF THE
FA. HOWEVER... WILL KEEP POP/WX FORECAST DRY FOR NOW. CLOUDS IN
THE SE ARE EXPECTED TO GRADUALLY DECREASE OVERNIGHT. SOME PATCHY
FOG IS STILL POSSIBLE TOWARDS MORNING IN NORTHERN PARTS OF THE FA
SO WILL KEEP MENTION IN THE FORECAST. UPDATES OUT SOON.
PREV DISCUSSION... /ISSUED 610 PM CDT SUN AUG 30 2015/
AVIATION...
MAINLY VFR CONDITIONS EXPECTED THROUGH THE FORECAST
PERIOD. THERE IS AN OUTSIDE CHANCE FOR SOME PATCHY FOG ACROSS
NORTHERN OKLAHOMA OVERNIGHT... BUT CHANCES REMAIN TOO LOW TO MENTION
AT THIS POINT. WINDS WILL BECOME SOUTHERLY ON MONDAY WITH SOME GUSTS
APPROACHING 20KTS ACROSS THE WEST BY AFTN.
30
PREV DISCUSSION... /ISSUED 220 PM CDT SUN AUG 30 2015/
DISCUSSION...
MAINLY DRY WEATHER AND NEAR OR SLIGHTLY ABOVE AVERAGE TEMPERATURES
ARE EXPECTED DURING THE NEXT SEVEN DAYS.
THROUGH 10 PM THIS EVENING...A FEW THUNDERSTORMS MAY FORM NEAR A
WEAK SURFACE FRONT OVER SOUTHERN OKLAHOMA...NEAR WAURIKA TO
COALGATE. CAPPING IS RATHER STRONG...HOWEVER A MID LEVEL
WEAKNESS CENTERED OVER EASTERN OKLAHOMA MAY BE ENOUGH FOR TO
ALLOW FOR ISOLATED DEVELOPMENT. THUS...WENT WITH A 20 PERCENT
CHANCE IN THESE LOCATIONS. IF STORMS FORM...THEY WOULD BE SLOW
MOVERS...PRODUCE LOCALIZED DOWNPOURS...AND GUSTY WINDS PERHAPS UP
TO 50 TO 60 MPH. ANY CONVECTION WOULD DIMINISH WITH THE LOSS OF
DAYTIME HEATING.
AFTER 10 PM THIS EVENING INTO MONDAY MORNING...PATCHY FOG MAY FORM
AGAIN ACROSS MAINLY NORTHERN OKLAHOMA. LATEST HRRR RUNS HAVE BEEN
CONSISTENT WITH DEPICTING LOW CLOUDS AND FOG OVER NEAR ALVA...
ENID...AND CHEROKEE. THIS SEEMS REASONABLE AS HIGHER SURFACE
DEWPOINTS ARE FORECAST TO MOVE INTO THESE LOCATIONS LATE TONIGHT.
THUS...ADDED MENTION OF PATCHY FOG. DOUBT FOG WILL BE TOO DENSE
OR WIDESPREAD SINCE NO RAIN WILL OCCUR IN THESE LOCATIONS TODAY.
MONDAY WILL BE MOSTLY SUNNY AND HOTTER WITH INCREASING SOUTH
SURFACE WINDS. CANNOT COMPLETELY RULE OUT A STRAY AFTERNOON OR
EVENING STORM IN SOUTHEAST OF A WAURIKA TO ADA LINE WHERE MID
LEVEL TEMPERATURES WILL BE A BIT COOLER AND CAPPING IS A BIT
WEAKER...BUT WILL NOT MENTION DUE TO LOW CONFIDENCE OF OCCURRENCE.
MONDAY NIGHT THROUGH NEXT SUNDAY...SEASONABLY HOT AND MAINLY DRY
WEATHER WILL CONTINUE WITH A WEAK MID/UPPER RIDGE OVERHEAD. LOW
STORM CHANCES MAY RETURN TO MAINLY NORTHWESTERN OKLAHOMA BY THE
WEEKEND...BUT CONFIDENCE IS LOW.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 70 92 71 92 / 0 0 0 0
HOBART OK 71 96 71 95 / 0 0 0 0
WICHITA FALLS TX 72 97 73 96 / 0 0 0 0
GAGE OK 69 95 70 94 / 0 0 0 0
PONCA CITY OK 70 93 71 92 / 0 0 0 0
DURANT OK 71 94 71 94 / 0 10 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/30
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
613 PM EDT MON AUG 31 2015
.SYNOPSIS...
A MODERATELY HIGH AMOUNT OF MOISTURE STREAMING EAST FROM THE OHIO
VALLEY WILL EXTEND ACROSS PENN THROUGH MUCH OF THIS WEEK. THE
CLOSE PROXIMITY OF A NEARLY EAST- WEST FRONTAL BOUNDARY ACROSS
PENNSYLVANIA WILL LEAD TO ISOLATED SHOWERS TODAY THROUGH THURSDAY.
HIGH PRESSURE OFF THE EAST COAST WILL RIDGE NORTHWEST INTO
PENNSYLVANIA AND LEAD TO TEMPERATURES WELL ABOVE NORMAL THIS
ENTIRE WEEK. IT WILL FEEL MORE LIKE THE MIDDLE OF SUMMER THAN
SEPTEMBER.
&&
.NEAR TERM /UNTIL 11 PM THIS EVENING/...
EVENING CONVECTION DWINDLING RAPIDLY AS MERE REMNANTS OF WHAT
EARLIER WERE LOCALLY HEAVY DOWNPOURS LINGER OVER SOUTHERN
PORTIONS OF THE LAUREL HIGHLANDS AND ARE JUST EXITING SOUTHERN
SCHUYLKILL COUNTY AS WELL. NOT EXPECTING ANY ADDITIONAL
DEVELOPMENT THIS EVENING...AS PER LATEST HRRR WHICH HAD A GOOD
HANDLE ON THE EXPLICIT DISSIPATION OF DIURNAL ACTIVITY THIS
EVENING. DROPPED LATE EVENING POPS AS A RESULT.
&&
.SHORT TERM /11 PM THIS EVENING THROUGH 6 PM TUESDAY/...
FOG IS NOT A SLAM-DUNK TONIGHT...BUT HIGH MOISTURE AND CLEARING
SKY SHOULD ALLOW FOR THE VALLEYS TO FOG UP AS IS USUAL IN SEPT.
YES...SEPT ALREADY. WILL ALSO MENTION SOME PATCHY FOG IN THE SRN
TIER WHERE IT IS RAINING. MINS SHOULD RUN IN THE MUGGY 60S AND
L70S AGAIN. TUESDAY LOOKS LIKE IT SHOULD HOLD FEWER SHOWERS...WITH
LITTLE FORCING AND ONLY WEAK BOUNDARIES RUNNING ABOUT.
THUS...WILL KEEP POPS TO 20S IN THE SW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
ANOMALOUS UPPER LEVEL RIDGE IS FORECAST TO DOMINATE THE EASTERN
THIRD TO HALF OF THE UNITED STATES TROUGH THE LONG TERM PERIOD.
THIS WILL LEAD TO ABOVE- NORMAL TEMPERATURES FOR MUCH OF THE
PERIOD. THE WARMTH AND INCREASING HUMIDITY SHOULD ALLOW FOR AT
LEAST A SLIGHT CHC OF DIURNAL CONVECTION EACH DAY...BUT WARM MID-
LEVELS WILL KEEP THE PROBABILITY OF WIDESPREAD RAINFALL QUITE LOW.
THE HIEST CHANCES FOR PRECIP WILL BE DURING THE MID-LATE WEEK
PERIOD /WED-THU-FRI/ WITH A COUPLE SUBTLE FEATURES. FIRST...A WEAK
UPPER LEVEL WAVE /BEST PROGGED ON THE ECMWF/ SLIPS OVERHEAD ON WED
AS THE BERMUDA HIGH BRIEFLY RECEDES. AT SAME TIME A WEAK BACKDOOR
COLD FRONT SLIPS SOUTHWARD OFF THE EAST COAST. THIS COULD HELP
POOL SOME LOW LEVEL MOISTURE OVER THE MID ATLANTIC AND OHIO VALLEY
AS MID LEVELS COOL JUST A BIT...BRINGING POTENTIAL FOR SCT TSTMS.
RIDGE BUILDS BACK IN FOR FRI...BUT ANOTHER SURFACE BACKDOOR FRONT
TRIES TO SLIP ACROSS THE STATE AS SURFACE HIGH EXPANDS IN FROM THE
NORTH. THIS BOUNDARY SHOULD BRING SCT CONVECTION FOR FRI.
EXTENDED MODELS HINT AT POTENTIAL FOR DAILY CONVECTION CONTINUING
INTO THE WEEKEND ALONG SOUTHER BORDER...BUT OVERALL CONDITIONS
WILL BE MAINLY RAIN-FREE.
TEMPS PEAK MIDWEEK WITH READINGS APPROACHING 90F IN THE SE...AND
EVEN GETTING INTO THE 80S ELSE HERE...EASILY WELL ABOVE NORMAL
FOR THE FIRST WEEK OF SEPT. LOWS WILL ALSO REMAIN QUITE MILD
MID/LATE WEEK AS HIGH HUMIDITY AIR HANGS AROUND. SLIGHTLY COOLER
BUT STILL ABOVE AVERAGE TEMPS WILL CONTINUE THROUGH THE WEEKEND.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
ISOLATED SHOWERS ACROSS SOUTHERN PA SHOULD DISSIPATE AROUND SUNSET
AS THE ATMOSPHERE COOLS/STABILIZES. MAIN FOCUS TONIGHT WILL BE ON
LATE NIGHT FOG...WHICH APPEARS A NEAR CERTAINTY IN THE DEEP VALLEYS
OF NORTH CENTRAL PA. LATEST MDL OUTPUT...COMBINED WITH CONDITIONAL
CLIMATOLOGY...IMPLY AT LEAST A 50 PCT CHC OF A PERIOD OF IFR
CONDS AT KBFD/KIPT/KAOO LATE TONIGHT...ONLY A SLIGHT CHC AT
KUNV/KLNS AND NEARLY NO CHC OF SIG REDUCTIONS AT KJST/KMDT.
ANY AM FOG SHOULD BURN OFF BY BTWN 12Z-14Z. OTHERWISE...HIGH
PRESSURE OFF THE EAST COAST WILL ENSURE WIDESPREAD VFR CONDS AND
LIGHT WINDS ON TUESDAY. THERE IS JUST A SLIGHT CHC OF A PM
SHRA/TSRA IN VICINITY OF KJST.
OUTLOOK...
WED-SAT...PATCHY AM FOG POSS...MAINLY KIPT/KBFD. ISOLD PM TSRA
IMPACTS POSSIBLE...MAINLY W.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DANGELO
LONG TERM...LAMBERT
AVIATION...DANGELO/FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
550 PM EDT MON AUG 31 2015
.SYNOPSIS...
A MODERATELY HIGH AMOUNT OF MOISTURE STREAMING EAST FROM THE OHIO
VALLEY WILL EXTEND ACROSS PENN THROUGH MUCH OF THIS WEEK. THE
CLOSE PROXIMITY OF A NEARLY EAST- WEST FRONTAL BOUNDARY ACROSS
PENNSYLVANIA WILL LEAD TO ISOLATED SHOWERS TODAY THROUGH THURSDAY.
HIGH PRESSURE OFF THE EAST COAST WILL RIDGE NORTHWEST INTO
PENNSYLVANIA AND LEAD TO TEMPERATURES WELL ABOVE NORMAL THIS
ENTIRE WEEK. IT WILL FEEL MORE LIKE THE MIDDLE OF SUMMER THAN
SEPTEMBER.
&&
.NEAR TERM /UNTIL 11 PM THIS EVENING/...
EVENING CONVECTION DWINDLING RAPIDLY AS MERE REMNANTS OF WHAT
EARLIER WERE LOCALLY HEAVY DOWNPOURS LINGER OVER SOUTHERN
PORTIONS OF THE LAUREL HIGHLANDS AND ARE JUST EXITING SOUTHERN
SCHUYLKILL COUNTY AS WELL. NOT EXPECTING ANY ADDITIONAL
DEVELOPMENT THIS EVENING...AS PER LATEST HRRR WHICH HAD A GOOD
HANDLE ON THE EXPLICIT DISSIPATION OF DIURNAL ACTIVITY THIS
EVENING. DROPPED LATE EVENING POPS AS A RESULT.
&&
.SHORT TERM /11 PM THIS EVENING THROUGH 6 PM TUESDAY/...
FOG IS NOT A SLAM-DUNK TONIGHT...BUT HIGH MOISTURE AND CLEARING
SKY SHOULD ALLOW FOR THE VALLEYS TO FOG UP AS IS USUAL IN SEPT.
YES...SEPT ALREADY. WILL ALSO MENTION SOME PATCHY FOG IN THE SRN
TIER WHERE IT IS RAINING. MINS SHOULD RUN IN THE MUGGY 60S AND
L70S AGAIN. TUESDAY LOOKS LIKE IT SHOULD HOLD FEWER SHOWERS...WITH
LITTLE FORCING AND ONLY WEAK BOUNDARIES RUNNING ABOUT.
THUS...WILL KEEP POPS TO 20S IN THE SW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
ANOMALOUS UPPER LEVEL RIDGE IS FORECAST TO DOMINATE THE EASTERN
THIRD TO HALF OF THE UNITED STATES TROUGH THE LONG TERM PERIOD.
THIS WILL LEAD TO ABOVE- NORMAL TEMPERATURES FOR MUCH OF THE
PERIOD. THE WARMTH AND INCREASING HUMIDITY SHOULD ALLOW FOR AT
LEAST A SLIGHT CHC OF DIURNAL CONVECTION EACH DAY...BUT WARM MID-
LEVELS WILL KEEP THE PROBABILITY OF WIDESPREAD RAINFALL QUITE LOW.
THE HIEST CHANCES FOR PRECIP WILL BE DURING THE MID-LATE WEEK
PERIOD /WED-THU-FRI/ WITH A COUPLE SUBTLE FEATURES. FIRST...A WEAK
UPPER LEVEL WAVE /BEST PROGGED ON THE ECMWF/ SLIPS OVERHEAD ON WED
AS THE BERMUDA HIGH BRIEFLY RECEDES. AT SAME TIME A WEAK BACKDOOR
COLD FRONT SLIPS SOUTHWARD OFF THE EAST COAST. THIS COULD HELP
POOL SOME LOW LEVEL MOISTURE OVER THE MID ATLANTIC AND OHIO VALLEY
AS MID LEVELS COOL JUST A BIT...BRINGING POTENTIAL FOR SCT TSTMS.
RIDGE BUILDS BACK IN FOR FRI...BUT ANOTHER SURFACE BACKDOOR FRONT
TRIES TO SLIP ACROSS THE STATE AS SURFACE HIGH EXPANDS IN FROM THE
NORTH. THIS BOUNDARY SHOULD BRING SCT CONVECTION FOR FRI.
EXTENDED MODELS HINT AT POTENTIAL FOR DAILY CONVECTION CONTINUING
INTO THE WEEKEND ALONG SOUTHER BORDER...BUT OVERALL CONDITIONS
WILL BE MAINLY RAIN-FREE.
TEMPS PEAK MIDWEEK WITH READINGS APPROACHING 90F IN THE SE...AND
EVEN GETTING INTO THE 80S ELSE HERE...EASILY WELL ABOVE NORMAL
FOR THE FIRST WEEK OF SEPT. LOWS WILL ALSO REMAIN QUITE MILD
MID/LATE WEEK AS HIGH HUMIDITY AIR HANGS AROUND. SLIGHTLY COOLER
BUT STILL ABOVE AVERAGE TEMPS WILL CONTINUE THROUGH THE WEEKEND.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
SHRA/TSRA OVER THE SC MTNS WILL DIE OFF THIS AFTN/EVENING. MOST
WILL BE GONE BEFORE 22-23Z. FOG IS LIKELY IN THE VALLEYS AND
PERHAPS AOO WHERE IT RAINED TODAY.
HIGH PRESSURE OFF THE EAST COAST WILL REMAIN IN PLACE FOR A FEW
DAYS. RETURN FLOW FROM THE W/SW WILL MAKE IT VERY WARM AND
HUMID...BUT A RIDGE ALOFT WILL SERVE TO SUPPRESS CONVECTION.
THUS...MOST OF THE TIME WILL BE VFR WITH ONLY EARLY AM FOG IN THE
VALLEYS AS IS NORMAL FOR SEPT. AFTN REDUCTIONS IN ISOLD SH/TSRA
ARE POSS THROUGH THE NEXT FEW DAYS...BUT THE MAJORITY OF THE TIME
WILL BE VFR.
OUTLOOK...
WED-SAT...PATCHY AM FOG POSS...MAINLY KIPT/KBFD. ISOLD PM TSRA
IMPACTS POSSIBLE...MAINLY W.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DANGELO
LONG TERM...LAMBERT
AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
359 PM EDT MON AUG 31 2015
.SYNOPSIS...
A MODERATELY HIGH AMOUNT OF MOISTURE STREAMING EAST FROM THE OHIO
VALLEY WILL EXTEND ACROSS PENN THROUGH MUCH OF THIS WEEK. THE
CLOSE PROXIMITY OF A NEARLY EAST-WEST FRONTAL BOUNDARY ACROSS
PENNSYLVANIA WILL LEAD TO ISOLATED SHOWERS TODAY THROUGH
THURSDAY.
HIGH PRESSURE OFF THE EAST COAST WILL RIDGE NORTHWEST INTO
PENNSYLVANIA AND LEAD TO TEMPERATURES WELL ABOVE NORMAL THIS
ENTIRE WEEK. IT WILL FEEL MORE LIKE THE MIDDLE OF SUMMER THAN
SEPTEMBER.
&&
.NEAR TERM /UNTIL 11 PM THIS EVENING/...
SHOWERS AND ISOLD TSRA OVER THE SRN MTNS ARE DRIFTING ESE. A FEW
OTHER CELLS ARE SPRINKLED ABOUT THE CWA. IN GENERAL...THESE ARE
NOT ALL THAT TALL...BUT AS WE SAW YESTERDAY...THE PWATS ARE
INCHING UP AND 1.5 TO 1.75 INCH VALUES ARE NOT UNCOMMON - MAINLY
IN THE SOUTH. THUS...A FEW MAY CONTAIN HEAVY DOWNPOURS. THE RAP
AND HRRR HAVE ALL OF THE CURRENT SHOWERS DYING A QUICK DEATH VERY
EARLY THIS EVENING - PERHAPS BEFORE SUNSET IN THE CENTRAL COS
WHERE INSTABILITY IS NOT SO GREAT AND SUBSIDENCE/DRYING IS QUITE
EVIDENT. WILL KEEP POPS UNDER 20 THERE AND NORTH FOR THE REST OF
THE AFTN/EVENING.
&&
.SHORT TERM /11 PM THIS EVENING THROUGH 6 PM TUESDAY/...
FOG IS NOT A SLAM-DUNK TONIGHT...BUT HIGH MOISTURE AND CLEARING
SKY SHOULD ALLOW FOR THE VALLEYS TO FOG UP AS IS USUAL IN SEPT.
YES...SEPT ALREADY. WILL ALSO MENTION SOME PATCHY FOG IN THE SRN
TIER WHERE IT IS RAINING. MINS SHOULD RUN IN THE MUGGY 60S AND
L70S AGAIN. TUESDAY LOOKS LIKE IT SHOULD HOLD FEWER SHOWERS...WITH
LITTLE FORCING AND ONLY WEAK BOUNDARIES RUNNING ABOUT.
THUS...WILL KEEP POPS TO 20S IN THE SW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
ANOMALOUS UPPER LEVEL RIDGE IS FORECAST TO DOMINATE THE EASTERN
THIRD TO HALF OF THE UNITED STATES TROUGH THE LONG TERM PERIOD.
THIS WILL LEAD TO ABOVE- NORMAL TEMPERATURES FOR MUCH OF THE
PERIOD. THE WARMTH AND INCREASING HUMIDITY SHOULD ALLOW FOR AT
LEAST A SLIGHT CHC OF DIURNAL CONVECTION EACH DAY...BUT WARM MID-
LEVELS WILL KEEP THE PROBABILITY OF WIDESPREAD RAINFALL QUITE LOW.
THE HIEST CHANCES FOR PRECIP WILL BE DURING THE MID-LATE WEEK
PERIOD /WED-THU-FRI/ WITH A COUPLE SUBTLE FEATURES. FIRST...A WEAK
UPPER LEVEL WAVE /BEST PROGGED ON THE ECMWF/ SLIPS OVERHEAD ON WED
AS THE BERMUDA HIGH BRIEFLY RECEDES. AT SAME TIME A WEAK BACKDOOR
COLD FRONT SLIPS SOUTHWARD OFF THE EAST COAST. THIS COULD HELP
POOL SOME LOW LEVEL MOISTURE OVER THE MID ATLANTIC AND OHIO VALLEY
AS MID LEVELS COOL JUST A BIT...BRINGING POTENTIAL FOR SCT TSTMS.
RIDGE BUILDS BACK IN FOR FRI...BUT ANOTHER SURFACE BACKDOOR FRONT
TRIES TO SLIP ACROSS THE STATE AS SURFACE HIGH EXPANDS IN FROM THE
NORTH. THIS BOUNDARY SHOULD BRING SCT CONVECTION FOR FRI.
EXTENDED MODELS HINT AT POTENTIAL FOR DAILY CONVECTION CONTINUING
INTO THE WEEKEND ALONG SOUTHER BORDER...BUT OVERALL CONDITIONS
WILL BE MAINLY RAIN-FREE.
TEMPS PEAK MIDWEEK WITH READINGS APPROACHING 90F IN THE SE...AND
EVEN GETTING INTO THE 80S ELSE HERE...EASILY WELL ABOVE NORMAL
FOR THE FIRST WEEK OF SEPT. LOWS WILL ALSO REMAIN QUITE MILD
MID/LATE WEEK AS HIGH HUMIDITY AIR HANGS AROUND. SLIGHTLY COOLER
BUT STILL ABOVE AVERAGE TEMPS WILL CONTINUE THROUGH THE WEEKEND.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
SHRA/TSRA OVER THE SC MTNS WILL DIE OFF THIS AFTN/EVENING. MOST
WILL BE GONE BEFORE 22-23Z. FOG IS LIKELY IN THE VALLEYS AND
PERHAPS AOO WHERE IT RAINED TODAY.
HIGH PRESSURE OFF THE EAST COAST WILL REMAIN IN PLACE FOR A FEW
DAYS. RETURN FLOW FROM THE W/SW WILL MAKE IT VERY WARM AND
HUMID...BUT A RIDGE ALOFT WILL SERVE TO SUPPRESS CONVECTION.
THUS...MOST OF THE TIME WILL BE VFR WITH ONLY EARLY AM FOG IN THE
VALLEYS AS IS NORMAL FOR SEPT. AFTN REDUCTIONS IN ISOLD SH/TSRA
ARE POSS THROUGH THE NEXT FEW DAYS...BUT THE MAJORITY OF THE TIME
WILL BE VFR.
OUTLOOK...
WED-SAT...PATCHY AM FOG POSS...MAINLY KIPT/KBFD. ISOLD PM TSRA
IMPACTS POSSIBLE...MAINLY W.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...LAMBERT
AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
308 PM EDT MON AUG 31 2015
.SYNOPSIS...
A MODERATELY HIGH AMOUNT OF MOISTURE STREAMING EAST FROM THE OHIO
VALLEY WILL EXTEND ACROSS PENN THROUGH MUCH OF THIS WEEK. THE
CLOSE PROXIMITY OF A NEARLY EAST-WEST FRONTAL BOUNDARY ACROSS
PENNSYLVANIA WILL LEAD TO ISOLATED SHOWERS TODAY THROUGH
THURSDAY.
HIGH PRESSURE OFF THE EAST COAST WILL RIDGE NORTHWEST INTO
PENNSYLVANIA AND LEAD TO TEMPERATURES WELL ABOVE NORMAL THIS
ENTIRE WEEK. IT WILL FEEL MORE LIKE THE MIDDLE OF SUMMER THAN
SEPTEMBER.
&&
.NEAR TERM /UNTIL 11 PM THIS EVENING/...
SHOWERS AND ISOLD TSRA OVER THE SRN MTNS ARE DRIFTING ESE. A FEW
OTHER CELLS ARE SPRINKLED ABOUT THE CWA. IN GENERAL...THESE ARE
NOT ALL THAT TALL...BUT AS WE SAW YESTERDAY...THE PWATS ARE
INCHING UP AND 1.5 TO 1.75 INCH VALUES ARE NOT UNCOMMON - MAINLY
IN THE SOUTH. THUS...A FEW MAY CONTAIN HEAVY DOWNPOURS. THE RAP
AND HRRR HAVE ALL OF THE CURRENT SHOWERS DYING A QUICK DEATH VERY
EARLY THIS EVENING - PERHAPS BEFORE SUNST IN THE CENTRAL COS
WHERE INSTABILITY IS NOT SO GREAT AND SUBSIDENCE/DRYING IS QUITE
EVIDENT. WILL KEEP POPS UNDER 20 THERE AND NORTH FOR THE REST OF
THE AFTN/EVENING.
&&
.SHORT TERM /11 PM THIS EVENING THROUGH 6 PM TUESDAY/...
FOG IS NOT A SLAM-DUNK TONIGHT...BUT HIGH MOISTURE AND CLEARING
SKY SHOULD ALLOW FOR THE VALLEYS TO FOG UP AS IS USUAL IN SEPT.
YES...SEPT ALREADY. WILL ALSO MENTION SOME PATCHY FOG IN THE SRN
TIER WHERE IT IS RAINING. MINS SHOULD RUN IN THE MUGGY 60S AND
L70S AGAIN. TUESDAY LOOKS LIKE IT SHOULD HOLD FEWER SHOWERS...WITH
LITTLE FORCING AND ONLY WEAK BOUNDARIES RUNNING ABOUT.
THUS...WILL KEEP POPS TO 20S IN THE SW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
ANOMALOUS UPPER LEVEL RIDGE WILL DOMINATE THE OHIO VALLEY AND
EASTERN UNITED STATES MUCH OF THE UPCOMING WEEK...WITH LATEST
GUIDANCE REMAINING FIRM FOR AN EXTENDED RUN OF 850HPA TEMPS
PEAKING DAILY AROUND 16-18C. THIS WILL TRANSLATE TO WELL ABOVE-
NORMAL SFC TEMPS. THIS WARMTH AND INCREASING HUMIDITY SHOULD ALLOW
FOR AT LEAST A SLIGHT CHC FOR DIURNAL CONVECTION EACH DAY...BUT
WARM MID-LEVELS WILL KEEP THE PROBABILITY OF WIDESPREAD RAINFALL
QUITE LOW.
BEST CHANCES FOR PRECIP WILL BE DURING THE MID-LATE WEEK PERIOD
/WED-THU-FRI/ WITH A COUPLE SUBTLE FEATURES. FIRST...A WEAK UPPER
LEVEL WAVE /BEST PROGGED ON THE ECMWF/ SLIPS OVERHEAD ON WED AS
BERMUDA HIGH BRIEFLY RECEDES. AT SAME TIME A WEAK BACKDOOR COLD
FRONT SLIPS SOUTHWARD OFF THE EAST COAST. THIS COULD HELP POOL
SOME LOW LEVEL MOISTURE OVER THE MID ATLANTIC AND OHIO VALLEY AS
MID LEVELS COOL JUST A BIT...BRINGING POTENTIAL FOR SCT TSTMS.
RIDGE BUILDS BACK IN FOR FRI...BUT ANOTHER SURFACE BACKDOOR FRONT
TRIES TO SLIP ACROSS THE STATE AS SURFACE HIGH EXPANDS IN FROM THE
NORTH. THIS BOUNDARY SHOULD BRING SCT CONVECTION FOR FRI.
EXTENDED MODELS HINT AT POTENTIAL FOR DAILY CONVECTION CONTINUING
INTO THE WEEKEND ALONG SOUTHER BORDER...BUT OVERALL CONDITIONS
WILL BE MAINLY RAIN-FREE.
TEMPS PEAK MIDWEEK WITH READINGS APPROACHING 90F IN THE SE...AND
EVEN GETTING INTO THE 80S ELSE HERE...EASILY WELL ABOVE NORMAL
FOR THE FIRST WEEK OF SEPT. LOWS WILL ALSO REMAIN QUITE MILD
MID/LATE WEEK AS HIGH HUMIDITY AIR HANGS AROUND. SLIGHTLY COOLER
BUT STILL ABOVE AVERAGE TEMPS WILL CONTINUE THROUGH THE WEEKEND.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
SHRA/TSRA OVER THE SC MTNS WILL DIE OFF THIS AFTN/EVENING. MOST
WILL BE GONE BEFORE 22-23Z. FOG IS LIKELY IN THE VALLEYS AND
PERHAPS AOO WHERE IT RAINED TODAY.
HIGH PRESSURE OFF THE EAST COAST WILL REMAIN IN PLACE FOR A FEW
DAYS. RETURN FLOW FROM THE W/SW WILL MAKE IT VERY WARM AND
HUMID...BUT A RIDGE ALOFT WILL SERVE TO SUPPRESS CONVECTION.
THUS...MOST OF THE TIME WILL BE VFR WITH ONLY EARLY AM FOG IN THE
VALLEYS AS IS NORMAL FOR SEPT. AFTN REDUCTIONS IN ISOLD SH/TSRA
ARE POSS THROUGH THE NEXT FEW DAYS...BUT THE MAJORITY OF THE TIME
WILL BE VFR.
OUTLOOK...
WED-SAT...PATCHY AM FOG POSS...MAINLY KIPT/KBFD. ISOLD PM TSRA
IMPACTS POSSIBLE...MAINLY W.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...LAMBERT/RXR
AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1137 AM EDT MON AUG 31 2015
.SYNOPSIS...
A MODERATELY HIGH AMOUNT OF MOISTURE STREAMING EAST FROM THE OHIO
VALLEY WILL EXTEND ACROSS PENN THROUGH MUCH OF THIS WEEK. THE
CLOSE PROXIMITY OF A NEARLY EAST-WEST FRONTAL BOUNDARY ACROSS
PENNSYLVANIA WILL LEAD TO ISOLATED SHOWERS TODAY THROUGH
THURSDAY.
HIGH PRESSURE OFF THE EAST COAST WILL RIDGE NORTHWEST INTO
PENNSYLVANIA AND LEAD TO TEMPERATURES WELL ABOVE NORMAL THIS
ENTIRE WEEK. IT WILL FEEL MORE LIKE THE MIDDLE OF SUMMER THAN
SEPTEMBER.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
1130 AM UPDATE...
SHOWERS DEVELOPING QUICKLY OVER THE LAURELS. SOME 50+ DBZ RETURNS
IN EACH CELL...BUT SO FAR NO LTG. WILL ASUME THAT THIS IS
INEVITABLE AND KEEP THUNDER IN THE FCST. 40-50 POPS ALONG THE SRN
BORDER WILL DO WELL. AS WITH YESTERDAY...THE CELLS ARE MOVING
ALONG SLOWLY...BUT ONE OR TWO WHICH ANCHOR OR REDEVELOP OVER THE
SAME AREA COULD MAKE ISOLATED SPOTS OF HEAVY RAIN.
730 AM UPDATE...
RADAR RETURNS ACROSS THE SRN TIER ARE VERY LIGHT AND MAY STILL BE
ALOFT. PATCH HEADED FOR KTHV SHOULD TELL THE TALE. BUT IT IS ALSO
THE AREA OF HIGHEST RETURNS AS WELL. THUS...THE 30 POPS ACROSS THE
SRN TIER STILL LOOK STELLAR AND SFC CONVERGENCE AND HEATING UNDER
LESS CLOUDS IN THE NORTH WILL POP A FEW CELLS THIS AFTN.
PREV...
SFC HIGH PRESSURE LOCATED JUST OFF THE SE U.S. COAST WILL SLOWLY
BUILD NORTHWEST...AS AN UPPER RIDGE LOCATED OVER THE UPPER GLAKES
AND MISS VALLEY MOVES EAST TO THE OHIO RIVER VALLEY AND MID
ATLANTIC REGION BY 12Z TUES.
925-850 MB THETA-E RIDGE EXTENDS FROM THE OHIO VALLEY...ENE THROUGH
PENN EARLY TODAY...WITH A WEAK/STALLED-OUT SFC FRONT EXTENDING
FROM DETROIT...SW TO ST LOUIS. THE NORTHERN PART OF THIS FRONT
WILL MOVE STEADILY EAST/SOUTHEAST AND BECOME LOCATED ACROSS
CENTRAL PENN THIS EVENING...AND STAY THERE THROUGH MUCH OF
TUESDAY. A BIT OF DRYING WILL BE SEEN ACROSS THE REGION NEAR AND
TO THE NORTH OF INTERSTATE 80.
03Z SREF PROB OF CAPE EXCEEDING 1000 J/KG CLIMBS TO THE 60-80
PERCENT RANGE THIS AFTERNOON...HOWEVER THE PROB OF 2000 J/KG IS
VERY LOW AT 10 PERCENT OR LESS TODAY THROUGH THURSDAY...THUS THE
LOW DIURNAL POP/CVRG FOR CONVECTION. 07Z HRRR CONFIRMS THIS
THINKING AS IT PLACES GENERALLY ISOLATED- SCATTERED/POPCORN LIKE
COVERAGE BETWEEN 17Z-22Z TODAY.
PLENTY OF BKN-OVC ALTO CU /TOPPED BY SOME CIRRUS/ BLANKETED THE
SE HALF TO TWO-THIRDS OF PENN EARLY TODAY...WHILE MOSTLY CLEAR
SKIES AND THE COOLEST TEMPS IN THE L60S WERE FOUND INVOF KBFD.
ELSEWHERE...TEMPS RANGED FROM THE MID 60S TO MID 70S - A RATHER
MUGGY EARLY MORNING FOR THE FINAL DAY OF METEOROLOGICAL SUMMER.
ASIDE FROM A HIGHLY ISOLATED AND BRIEF LIGHT SHOWER OR TWO ON THE
RADAR SCOPE EARLY TODAY...CONDITIONS ACROSS MUCH OF CENTRAL AND
NORTHERN PENN WILL BE DRY WITH A VERY LIGHT AND VARIABLE WIND
THROUGH THE MID MORNING HOURS.
FARTHER SOUTH...WEAK UPPER LOW OVER THE WESTERN CAROLINAS WILL
LIFT NORTHWARD OVERNIGHT ON THE WESTERN PERIPHERY OF THE SPRAWLING
WESTERN ATLANTIC UPPER HIGH CIRCULATION. THIS WILL MAINTAIN THE
FOCUS FOR POOLING MOISTURE AND FORCING FOR SHOWER ACTIVITY THROUGH
THE PRE DAWN HOURS ACROSS MY FAR SOUTH. AGAIN...AREAS TO THE
NORTH SHOULD BE DRY AFTER 06Z AS DEFORMATION LESSENS AND FORCING
FOCUS SHIFTS TO AREAS ALONG AND SOUTH OF MY SOUTHERN TIER.
SOME FOG HAS FORMED...BUT VSBYS ARE HOLDING UP AOA 1 SM
MINS AROUND SUNRISE TODAY WILL RUN IN THE 60S IN PRACTICALLY ALL
LOCATIONS AS DEWPOINTS SHOULD NOT GO ANY LOWER THAN 60F. A FEW OF
THE NORMALLY COLD SPOTS NEAR...AND THE EAST OF KBFD WILL SEE A LOW
TEMP IN THE MID 50S.
HIGH TEMPS THIS AFTERNOON WILL VARY FROM THE U70S OVER THE HIGHEST
ELEVATIONS OF THE NORTH AND WEST...TO THE MID AND UPPER 80S ACROSS
OUR SE ZONES.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH 6 AM TUESDAY/...
TONIGHT SHOULD BE A NEAR REPEAT OF SUNDAY NIGHT/EARLY MONDAY WITH
VARIABLE AMTS OF MAINLY MID AND HIGH CLOUDS AND PERHAPS JUST A
COUPLE SMALL SHOWERS ROAMING THE STREETS.
CONSALL TEMP BLEND YIELDS LOWS AROUND 60F ACROSS THE NRN
MTNS...AND IN THE MID TO UPPER 60S ELSEWHERE.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
ANOMALOUS UPPER LEVEL RIDGE WILL DOMINATE THE OHIO VALLEY AND
EASTERN UNITED STATES MUCH OF THE UPCOMING WEEK...WITH LATEST
GUIDANCE REMAINING FIRM FOR AN EXTENDED RUN OF 850HPA TEMPS
PEAKING DAILY AROUND 16-18C. THIS WILL TRANSLATE TO WELL ABOVE-
NORMAL SFC TEMPS. THIS WARMTH AND INCREASING HUMIDITY SHOULD ALLOW
FOR AT LEAST A SLIGHT CHC FOR DIURNAL CONVECTION EACH DAY...BUT
WARM MID-LEVELS WILL KEEP THE PROBABILITY OF WIDESPREAD RAINFALL
QUITE LOW.
BEST CHANCES FOR PRECIP WILL BE DURING THE MID-LATE WEEK PERIOD
/WED-THU-FRI/ WITH A COUPLE SUBTLE FEATURES. FIRST...A WEAK UPPER
LEVEL WAVE /BEST PROGGED ON THE ECMWF/ SLIPS OVERHEAD ON WED AS
BERMUDA HIGH BRIEFLY RECEDES. AT SAME TIME A WEAK BACKDOOR COLD
FRONT SLIPS SOUTHWARD OFF THE EAST COAST. THIS COULD HELP POOL
SOME LOW LEVEL MOISTURE OVER THE MID ATLANTIC AND OHIO VALLEY AS
MID LEVELS COOL JUST A BIT...BRINGING POTENTIAL FOR SCT TSTMS.
RIDGE BUILDS BACK IN FOR FRI...BUT ANOTHER SURFACE BACKDOOR FRONT
TRIES TO SLIP ACROSS THE STATE AS SURFACE HIGH EXPANDS IN FROM THE
NORTH. THIS BOUNDARY SHOULD BRING SCT CONVECTION FOR FRI.
EXTENDED MODELS HINT AT POTENTIAL FOR DAILY CONVECTION CONTINUING
INTO THE WEEKEND ALONG SOUTHER BORDER...BUT OVERALL CONDITIONS
WILL BE MAINLY RAIN-FREE.
TEMPS PEAK MIDWEEK WITH READINGS APPROACHING 90F IN THE SE...AND
EVEN GETTING INTO THE 80S ELSE HERE...EASILY WELL ABOVE NORMAL
FOR THE FIRST WEEK OF SEPT. LOWS WILL ALSO REMAIN QUITE MILD
MID/LATE WEEK AS HIGH HUMIDITY AIR HANGS AROUND. SLIGHTLY COOLER
BUT STILL ABOVE AVERAGE TEMPS WILL CONTINUE THROUGH THE WEEKEND.
&&
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
WIDESPREAD VFR CONDS AND LIGHT WIND APPEAR VERY LIKELY WITH ISOLD
TO SCT SHRA/TSRA OVER THE SRN TIER AND NRN MTNS. THE MAY BE A
SHRA OR TWO IN THE CENTRAL MTNS...BUT LESS OF A CHANCE OF ANY
VSBY/CIG REDUCTIONS THERE. HIGH PRESSURE WILL REMAIN OFF THE MID
ATLANTIC COAST.
OUTLOOK...
TUE-FRI...PATCHY AM FOG POSS...MAINLY KBFD. ISOLD PM TSRA IMPACTS
POSSIBLE...MAINLY W.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/RXR
AVIATION...DANGELO/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
754 AM EDT MON AUG 31 2015
.SYNOPSIS...
A MODERATELY HIGH AMOUNT OF MOISTURE STREAMING EAST FROM THE OHIO
VALLEY WILL EXTEND ACROSS PENN THROUGH MUCH OF THIS WEEK. THE
CLOSE PROXIMITY OF A NEARLY EAST-WEST FRONTAL BOUNDARY ACROSS
PENNSYLVANIA WILL LEAD TO ISOLATED MAINLY AFTERNOON AND EARLY
EVENING SHRA/TSRA TODAY THROUGH THURSDAY.
HIGH PRESSURE OFF THE EAST COAST WILL RIDGE NORTHWEST INTO
PENNSYLVANIA AND LEAD TO TEMPERATURES WELL ABOVE NORMAL THIS
ENTIRE WEEK. IT WILL FEEL MORE LIKE THE MIDDLE OF SUMMER THAN
SEPTEMBER.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
730 AM UPDATE...
RADAR RETURNS ACROSS THE SRN TIER ARE VERY LIGHT AND MAY STILL BE
ALOFT. PATCH HEADED FOR KTHV SHOULD TELL THE TALE. BUT IT IS ALSO
THE AREA OF HIGHEST RETURNS AS WELL. THUS...THE 30 POPS ACROSS THE
SRN TIER STILL LOOK STELLAR AND SFC CONVERGENCE AND HEATING UNDER
LESS CLOUDS IN THE NORTH WILL POP A FEW CELLS THIS AFTN.
PREV...
SFC HIGH PRESSURE LOCATED JUST OFF THE SE U.S. COAST WILL SLOWLY
BUILD NORTHWEST...AS AN UPPER RIDGE LOCATED OVER THE UPPER GLAKES
AND MISS VALLEY MOVES EAST TO THE OHIO RIVER VALLEY AND MID
ATLANTIC REGION BY 12Z TUES.
925-850 MB THETA-E RIDGE EXTENDS FROM THE OHIO VALLEY...ENE THROUGH
PENN EARLY TODAY...WITH A WEAK/STALLED-OUT SFC FRONT EXTENDING
FROM DETROIT...SW TO ST LOUIS. THE NORTHERN PART OF THIS FRONT
WILL MOVE STEADILY EAST/SOUTHEAST AND BECOME LOCATED ACROSS
CENTRAL PENN THIS EVENING...AND STAY THERE THROUGH MUCH OF
TUESDAY. A BIT OF DRYING WILL BE SEEN ACROSS THE REGION NEAR AND
TO THE NORTH OF INTERSTATE 80.
03Z SREF PROB OF CAPE EXCEEDING 1000 J/KG CLIMBS TO THE 60-80
PERCENT RANGE THIS AFTERNOON...HOWEVER THE PROB OF 2000 J/KG IS
VERY LOW AT 10 PERCENT OR LESS TODAY THROUGH THURSDAY...THUS THE
LOW DIURNAL POP/CVRG FOR CONVECTION. 07Z HRRR CONFIRMS THIS
THINKING AS IT PLACES GENERALLY ISOLATED- SCATTERED/POPCORN LIKE
COVERAGE BETWEEN 17Z-22Z TODAY.
PLENTY OF BKN-OVC ALTO CU /TOPPED BY SOME CIRRUS/ BLANKETED THE
SE HALF TO TWO-THIRDS OF PENN EARLY TODAY...WHILE MOSTLY CLEAR
SKIES AND THE COOLEST TEMPS IN THE L60S WERE FOUND INVOF KBFD.
ELSEWHERE...TEMPS RANGED FROM THE MID 60S TO MID 70S - A RATHER
MUGGY EARLY MORNING FOR THE FINAL DAY OF METEOROLOGICAL SUMMER.
ASIDE FROM A HIGHLY ISOLATED AND BRIEF LIGHT SHOWER OR TWO ON THE
RADAR SCOPE EARLY TODAY...CONDITIONS ACROSS MUCH OF CENTRAL AND
NORTHERN PENN WILL BE DRY WITH A VERY LIGHT AND VARIABLE WIND
THROUGH THE MID MORNING HOURS.
FARTHER SOUTH...WEAK UPPER LOW OVER THE WESTERN CAROLINAS WILL
LIFT NORTHWARD OVERNIGHT ON THE WESTERN PERIPHERY OF THE SPRAWLING
WESTERN ATLANTIC UPPER HIGH CIRCULATION. THIS WILL MAINTAIN THE
FOCUS FOR POOLING MOISTURE AND FORCING FOR SHOWER ACTIVITY THROUGH
THE PRE DAWN HOURS ACROSS MY FAR SOUTH. AGAIN...AREAS TO THE
NORTH SHOULD BE DRY AFTER 06Z AS DEFORMATION LESSENS AND FORCING
FOCUS SHIFTS TO AREAS ALONG AND SOUTH OF MY SOUTHERN TIER.
SOME FOG HAS FORMED...BUT VSBYS ARE HOLDING UP AOA 1 SM
MINS AROUND SUNRISE TODAY WILL RUN IN THE 60S IN PRACTICALLY ALL
LOCATIONS AS DEWPOINTS SHOULD NOT GO ANY LOWER THAN 60F. A FEW OF
THE NORMALLY COLD SPOTS NEAR...AND THE EAST OF KBFD WILL SEE A LOW
TEMP IN THE MID 50S.
HIGH TEMPS THIS AFTERNOON WILL VARY FROM THE U70S OVER THE HIGHEST
ELEVATIONS OF THE NORTH AND WEST...TO THE MID AND UPPER 80S ACROSS
OUR SE ZONES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
TONIGHT SHOULD BE A NEAR REPEAT OF SUNDAY NIGHT/EARLY MONDAY WITH
VARIABLE AMTS OF MAINLY MID AND HIGH CLOUDS AND PERHAPS JUST A
COUPLE SMALL SHOWERS ROAMING THE STREETS.
CONSALL TEMP BLEND YIELDS LOWS AROUND 60F ACROSS THE NRN
MTNS...AND IN THE MID TO UPPER 60S ELSEWHERE.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
ANOMALOUS UPPER LEVEL RIDGE WILL DOMINATE THE OHIO VALLEY AND
EASTERN UNITED STATES MUCH OF THE UPCOMING WEEK...WITH LATEST
GUIDANCE REMAINING FIRM FOR AN EXTENDED RUN OF 850HPA TEMPS
PEAKING DAILY AROUND 16-18C. THIS WILL TRANSLATE TO WELL ABOVE-
NORMAL SFC TEMPS. THIS WARMTH AND INCREASING HUMIDITY SHOULD ALLOW
FOR AT LEAST A SLIGHT CHC FOR DIURNAL CONVECTION EACH DAY...BUT
WARM MID-LEVELS WILL KEEP THE PROBABILITY OF WIDESPREAD RAINFALL
QUITE LOW.
BEST CHANCES FOR PRECIP WILL BE DURING THE MID-LATE WEEK PERIOD
/WED-THU-FRI/ WITH A COUPLE SUBTLE FEATURES. FIRST...A WEAK UPPER
LEVEL WAVE /BEST PROGGED ON THE ECMWF/ SLIPS OVERHEAD ON WED AS
BERMUDA HIGH BRIEFLY RECEDES. AT SAME TIME A WEAK BACKDOOR COLD
FRONT SLIPS SOUTHWARD OFF THE EAST COAST. THIS COULD HELP POOL
SOME LOW LEVEL MOISTURE OVER THE MID ATLANTIC AND OHIO VALLEY AS
MID LEVELS COOL JUST A BIT...BRINGING POTENTIAL FOR SCT TSTMS.
RIDGE BUILDS BACK IN FOR FRI...BUT ANOTHER SURFACE BACKDOOR FRONT
TRIES TO SLIP ACROSS THE STATE AS SURFACE HIGH EXPANDS IN FROM THE
NORTH. THIS BOUNDARY SHOULD BRING SCT CONVECTION FOR FRI.
EXTENDED MODELS HINT AT POTENTIAL FOR DAILY CONVECTION CONTINUING
INTO THE WEEKEND ALONG SOUTHER BORDER...BUT OVERALL CONDITIONS
WILL BE MAINLY RAIN-FREE.
TEMPS PEAK MIDWEEK WITH READINGS APPROACHING 90F IN THE SE...AND
EVEN GETTING INTO THE 80S ELSE HERE...EASILY WELL ABOVE NORMAL
FOR THE FIRST WEEK OF SEPT. LOWS WILL ALSO REMAIN QUITE MILD
MID/LATE WEEK AS HIGH HUMIDITY AIR HANGS AROUND. SLIGHTLY COOLER
BUT STILL ABOVE AVERAGE TEMPS WILL CONTINUE THROUGH THE WEEKEND.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
EARLY MORNING FOG HAS REMAINED ISOLATED AT IPT AND BFD...WITH IFR
AND MVFR RESPECTIVELY. ANY AM VALLEY FOG WILL BURN OFF BY LATE
AM. OTHERWISE...WIDESPREAD VFR CONDS AND LIGHT WIND APPEAR VERY
LIKELY MONDAY WITH ONLY ISOLD LATE DAY SHRA/TSRA POSSIBLE...AS
HIGH PRESSURE BUILDS OFF THE MID ATLANTIC COAST. SHOWERS WILL BE
MOST LIKELY THROUGH THE SOUTHERN TAF SITES WITH LNS AND MDT MOST
LIKELY...MAINLY BETWEEN NOW AND THROUGH THE EARLY AFTERNOON HOURS.
OUTLOOK...
TUE-FRI...PATCHY AM FOG POSS...MAINLY KBFD. ISOLD PM TSRA IMPACTS
POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/RXR
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
704 AM EDT MON AUG 31 2015
.SYNOPSIS...
A MODERATELY HIGH AMOUNT OF MOISTURE STREAMING EAST FROM THE OHIO
VALLEY WILL EXTEND ACROSS PENN THROUGH MUCH OF THIS WEEK. THE
CLOSE PROXIMITY OF A NEARLY EAST-WEST FRONTAL BOUNDARY ACROSS
PENNSYLVANIA WILL LEAD TO ISOLATED MAINLY AFTERNOON AND EARLY
EVENING SHRA/TSRA TODAY THROUGH THURSDAY.
HIGH PRESSURE OFF THE EAST COAST WILL RIDGE NORTHWEST INTO
PENNSYLVANIA AND LEAD TO TEMPERATURES WELL ABOVE NORMAL THIS
ENTIRE WEEK. IT WILL FEEL MORE LIKE THE MIDDLE OF SUMMER THAN
SEPTEMBER.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SFC HIGH PRESSURE LOCATED JUST OFF THE SE U.S. COAST WILL SLOWLY
BUILD NORTHWEST...AS AN UPPER RIDGE LOCATED OVER THE UPPER GLAKES
AND MISS VALLEY MOVES EAST TO THE OHIO RIVER VALLEY AND MID
ATLANTIC REGION BY 12Z TUES.
925-850 MB THETA-E RIDGE EXTENDS FROM THE OHIO VALLEY...ENE THROUGH
PENN EARLY TODAY...WITH A WEAK/STALLED-OUT SFC FRONT EXTENDING
FROM DETROIT...SW TO ST LOUIS. THE NORTHERN PART OF THIS FRONT
WILL MOVE STEADILY EAST/SOUTHEAST AND BECOME LOCATED ACROSS
CENTRAL PENN THIS EVENING...AND STAY THERE THROUGH MUCH OF
TUESDAY. A BIT OF DRYING WILL BE SEEN ACROSS THE REGION NEAR AND
TO THE NORTH OF INTERSTATE 80.
03Z SREF PROB OF CAPE EXCEEDING 1000 J/KG CLIMBS TO THE 60-80
PERCENT RANGE THIS AFTERNOON...HOWEVER THE PROB OF 2000 J/KG IS
VERY LOW AT 10 PERCENT OR LESS TODAY THROUGH THURSDAY...THUS THE
LOW DIURNAL POP/CVRG FOR CONVECTION. 07Z HRRR CONFIRMS THIS
THINKING AS IT PLACES GENERALLY ISOLATED- SCATTERED/POPCORN LIKE
COVERAGE BETWEEN 17Z-22Z TODAY.
PLENTY OF BKN-OVC ALTO CU /TOPPED BY SOME CIRRUS/ BLANKETED THE
SE HALF TO TWO-THIRDS OF PENN EARLY TODAY...WHILE MOSTLY CLEAR
SKIES AND THE COOLEST TEMPS IN THE L60S WERE FOUND INVOF KBFD.
ELSEWHERE...TEMPS RANGED FROM THE MID 60S TO MID 70S - A RATHER
MUGGY EARLY MORNING FOR THE FINAL DAY OF METEOROLOGICAL SUMMER.
ASIDE FROM A HIGHLY ISOLATED AND BRIEF LIGHT SHOWER OR TWO ON THE
RADAR SCOPE EARLY TODAY...CONDITIONS ACROSS MUCH OF CENTRAL AND
NORTHERN PENN WILL BE DRY WITH A VERY LIGHT AND VARIABLE WIND
THROUGH THE MID MORNING HOURS.
FARTHER SOUTH...WEAK UPPER LOW OVER THE WESTERN CAROLINAS WILL
LIFT NORTHWARD OVERNIGHT ON THE WESTERN PERIPHERY OF THE SPRAWLING
WESTERN ATLANTIC UPPER HIGH CIRCULATION. THIS WILL MAINTAIN THE
FOCUS FOR POOLING MOISTURE AND FORCING FOR SHOWER ACTIVITY THROUGH
THE PRE DAWN HOURS ACROSS MY FAR SOUTH. AGAIN...AREAS TO THE
NORTH SHOULD BE DRY AFTER 06Z AS DEFORMATION LESSENS AND FORCING
FOCUS SHIFTS TO AREAS ALONG AND SOUTH OF MY SOUTHERN TIER.
SOME FOG HAS FORMED...BUT VSBYS ARE HOLDING UP AOA 1 SM
MINS AROUND SUNRISE TODAY WILL RUN IN THE 60S IN PRACTICALLY ALL
LOCATIONS AS DEWPOINTS SHOULD NOT GO ANY LOWER THAN 60F. A FEW OF
THE NORMALLY COLD SPOTS NEAR...AND THE EAST OF KBFD WILL SEE A LOW
TEMP IN THE MID 50S.
HIGH TEMPS THIS AFTERNOON WILL VARY FROM THE U70S OVER THE HIGHEST
ELEVATIONS OF THE NORTH AND WEST...TO THE MID AND UPPER 80S ACROSS
OUR SE ZONES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
TONIGHT SHOULD BE A NEAR REPEAT OF SUNDAY NIGHT/EARLY MONDAY WITH
VARIABLE AMTS OF MAINLY MID AND HIGH CLOUDS AND PERHAPS JUST A
COUPLE SMALL SHOWERS ROAMING THE STREETS.
CONSALL TEMP BLEND YIELDS LOWS AROUND 60F ACROSS THE NRN
MTNS...AND IN THE MID TO UPPER 60S ELSEWHERE.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
ANOMALOUS UPPER LEVEL RIDGE WILL DOMINATE THE OHIO VALLEY AND
EASTERN UNITED STATES MUCH OF THE UPCOMING WEEK...WITH LATEST
GUIDANCE REMAINING FIRM FOR AN EXTENDED RUN OF 850HPA TEMPS
PEAKING DAILY AROUND 16-18C. THIS WILL TRANSLATE TO WELL ABOVE-
NORMAL SFC TEMPS. THIS WARMTH AND INCREASING HUMIDITY SHOULD ALLOW
FOR AT LEAST A SLIGHT CHC FOR DIURNAL CONVECTION EACH DAY...BUT
WARM MID-LEVELS WILL KEEP THE PROBABILITY OF WIDESPREAD RAINFALL
QUITE LOW.
BEST CHANCES FOR PRECIP WILL BE DURING THE MID-LATE WEEK PERIOD
/WED-THU-FRI/ WITH A COUPLE SUBTLE FEATURES. FIRST...A WEAK UPPER
LEVEL WAVE /BEST PROGGED ON THE ECMWF/ SLIPS OVERHEAD ON WED AS
BERMUDA HIGH BRIEFLY RECEDES. AT SAME TIME A WEAK BACKDOOR COLD
FRONT SLIPS SOUTHWARD OFF THE EAST COAST. THIS COULD HELP POOL
SOME LOW LEVEL MOISTURE OVER THE MID ATLANTIC AND OHIO VALLEY AS
MID LEVELS COOL JUST A BIT...BRINGING POTENTIAL FOR SCT TSTMS.
RIDGE BUILDS BACK IN FOR FRI...BUT ANOTHER SURFACE BACKDOOR FRONT
TRIES TO SLIP ACROSS THE STATE AS SURFACE HIGH EXPANDS IN FROM THE
NORTH. THIS BOUNDARY SHOULD BRING SCT CONVECTION FOR FRI.
EXTENDED MODELS HINT AT POTENTIAL FOR DAILY CONVECTION CONTINUING
INTO THE WEEKEND ALONG SOUTHER BORDER...BUT OVERALL CONDITIONS
WILL BE MAINLY RAIN-FREE.
TEMPS PEAK MIDWEEK WITH READINGS APPROACHING 90F IN THE SE...AND
EVEN GETTING INTO THE 80S ELSE HERE...EASILY WELL ABOVE NORMAL
FOR THE FIRST WEEK OF SEPT. LOWS WILL ALSO REMAIN QUITE MILD
MID/LATE WEEK AS HIGH HUMIDITY AIR HANGS AROUND. SLIGHTLY COOLER
BUT STILL ABOVE AVERAGE TEMPS WILL CONTINUE THROUGH THE WEEKEND.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
EARLY MORNING FOG HAS REMAINED ISOLATED AT IPT AND BFD...WITH IFR
AND MVFR RESPECTIVELY. ANY AM VALLEY FOG WILL BURN OFF BY LATE
AM. OTHERWISE...WIDESPREAD VFR CONDS AND LIGHT WIND APPEAR VERY
LIKELY MONDAY WITH ONLY ISOLD LATE DAY SHRA/TSRA POSSIBLE...AS
HIGH PRESSURE BUILDS OFF THE MID ATLANTIC COAST. SHOWERS WILL BE
MOST LIKELY THROUGH THE SOUTHERN TAF SITES WITH LNS AND MDT MOST
LIKELY...MAINLY BETWEEN NOW AND THROUGH THE EARLY AFTERNOON HOURS.
OUTLOOK...
TUE-FRI...PATCHY AM FOG POSS...MAINLY KBFD. ISOLD PM TSRA IMPACTS
POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/RXR
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
548 AM EDT MON AUG 31 2015
.SYNOPSIS...
A MODERATELY HIGH AMOUNT OF MOISTURE STREAMING EAST FROM THE OHIO
VALLEY WILL EXTEND ACROSS PENN THROUGH MUCH OF THIS WEEK. THE
CLOSE PROXIMITY OF A NEARLY EAST-WEST FRONTAL BOUNDARY ACROSS
PENNSYLVANIA WILL LEAD TO ISOLATED MAINLY AFTERNOON AND EARLY
EVENING SHRA/TSRA TODAY THROUGH THURSDAY.
HIGH PRESSURE OFF THE EAST COAST WILL RIDGE NORTHWEST INTO
PENNSYLVANIA AND LEAD TO TEMPERATURES WELL ABOVE NORMAL THIS
ENTIRE WEEK. IT WILL FEEL MORE LIKE THE MIDDLE OF SUMMER THAN
SEPTEMBER.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SFC HIGH PRESSURE LOCATED JUST OFF THE SE U.S. COAST WILL SLOWLY
BUILD NORTHWEST...AS AN UPPER RIDGE LOCATED OVER THE UPPER GLAKES
AND MISS VALLEY MOVES EAST TO THE OHIO RIVER VALLEY AND MID
ATLANIC REGION BY 12Z TUES.
925-850 MB THETA-E RIDGE EXTENDS FROM THE OHIO VALLEY...ENE THROUGH
PENN EARLY TODAY...WITH A WEAK/STALLED-OUT SFC FRONT EXTENDING
FROM DETROIT...SW TO ST LOUIS. THE NORTHERN PART OF THIS FRONT
WILL MOVE STEADILY EAST/SOUTHEAST AND BECOME LOCATED ACROSS
CENTRAL PENN THIS EVENING...AND STAY THERE THROUGH MUCH OF
TUESDAY. A BIT OF DRYING WILL BE SEEN ACROSS THE REGION NEAR AND
TO THE NORTH OF INTERSTATE 80.
03Z SREF PROB OF CAPE EXCEEDING 1000 J/KG CLIMBS TO THE 60-80
PERCENT RANGE THIS AFTERNOON...HOWEVER THE PROB OF 2000 J/KG IS
VERY LOW AT 10 PERCENT OR LESS TODAY THROUGH THURSDAY...THUS THE
LOW DIURNAL POP/CVRG FOR CONVECTION. 07Z HRRR CONFIRMS THIS
THINKING AS IT PLACES GENERALLY ISOLATED- SCATTERED/POPCORN LIKE
COVERAGE BETWEEN 17Z-22Z TODAY.
PLENTY OF BKN-OVC ALTO CU /TOPPED BY SOME CIRRUS/ BLANKETED THE
SE HALF TO TWO-THIRDS OF PENN EARLY TODAY...WHILE MOSTLY CLEAR
SKIES AND THE COOLEST TEMPS IN THE L60S WERE FOUND INVOF KBFD.
ELSEWHERE...TEMPS RANGED FROM THE MID 60S TO MID 70S - A RATHER
MUGGY EARLY MORNING FOR THE FINAL DAY OF METEOROLOGICAL SUMMER.
ASIDE FROM A HIGHLY ISOLATED AND BRIEF LIGHT SHOWER OR TWO ON THE
RADAR SCOPE EARLY TODAY...CONDITIONS ACROSS MUCH OF CENTRAL AND
NORTHERN PENN WILL BE DRY WITH A VERY LIGHT AND VARIABLE WIND
THROUGH THE MID MORNING HOURS.
FARTHER SOUTH...WEAK UPPER LOW OVER THE WESTERN CAROLINAS WILL
LIFT NORTHWARD OVERNIGHT ON THE WESTERN PERIPHERY OF THE SPRAWLING
WESTERN ATLANTIC UPPER HIGH CIRCULATION. THIS WILL MAINTAIN THE
FOCUS FOR POOLING MOISTURE AND FORCING FOR SHOWER ACTIVITY THROUGH
THE PRE DAWN HOURS ACROSS MY FAR SOUTH. AGAIN...AREAS TO THE
NORTH SHOULD BE DRY AFTER 06Z AS DEFORMATION LESSENS AND FORCING
FOCUS SHIFTS TO AREAS ALONG AND SOUTH OF MY SOUTHERN TIER.
SOME FOG HAS FORMED...BUT VSBYS ARE HOLDING UP AOA 1 SM
MINS AROUND SUNRISE TODAY WILL RUN IN THE 60S IN PRACTICALLY ALL
LOCATIONS AS DEWPOINTS SHOULD NOT GO ANY LOWER THAN 60F. A FEW OF
THE NORMALLY COLD SPOTS NEAR...AND THE EAST OF KBFD WILL SEE A LOW
TEMP IN THE MID 50S.
HIGH TEMPS THIS AFTERNOON WILL VARY FROM THE U70S OVER THE HIGHEST
ELEVATIONS OF THE NORTH AND WEST...TO THE MID AND UPPER 80S ACROSS
OUR SE ZONES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
TONIGHT SHOULD BE A NEAR REPEAT OF SUNDAY NIGHT/EARLY MONDAY WITH
VARIABLE AMTS OF MAINLY MID AND HIGH CLOUDS AND PERHAPS JUST A
COUPLE SMALL SHOWERS ROAMING THE STREETS.
CONSALL TEMP BLEND YIELDS LOWS AROUND 60F ACROSS THE NRN
MTNS...AND INTHE MID TO UPPER 60S ELSEWHERE.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
ANOMALOUS UPPER LEVEL RIDGE WILL DOMINATE THE OHIO VALLEY AND
EASTERN UNITED STATES MUCH OF THE UPCOMING WEEK...WITH LATEST
GUIDANCE REMAINING FIRM FOR AN EXTENDED RUN OF 850HPA TEMPS
PEAKING DAILY AROUND 16-18C. THIS WILL TRANSLATE TO WELL ABOVE-
NORMAL SFC TEMPS. THIS WARMTH AND INCREASING HUMIDITY SHOULD ALLOW
FOR AT LEAST A SLIGHT CHC FOR DIURNAL CONVECTION EACH DAY...BUT
WARM MID-LEVELS WILL KEEP THE PROBABILITY OF WIDESPREAD RAINFALL
QUITE LOW.
BEST CHANCES FOR PRECIP WILL BE DURING THE MID-LATE WEEK PERIOD
/WED-THU-FRI/ WITH A COUPLE SUBTLE FEATURES. FIRST...A WEAK UPPER
LEVEL WAVE /BEST PROGGED ON THE ECMWF/ SLIPS OVERHEAD ON WED AS
BERMUDA HIGH BRIEFLY RECEDES. AT SAME TIME A WEAK BACKDOOR COLD
FRONT SLIPS SOUTHWARD OFF THE EAST COAST. THIS COULD HELP POOL
SOME LOW LEVEL MOISTURE OVER THE MID ATLANTIC AND OHIO VALLEY AS
MID LEVELS COOL JUST A BIT...BRINGING POTENTIAL FOR SCT TSTMS.
RIDGE BUILDS BACK IN FOR FRI...BUT ANOTHER SURFACE BACKDOOR FRONT
TRIES TO SLIP ACROSS THE STATE AS SURFACE HIGH EXPANDS IN FROM THE
NORTH. THIS BOUNDARY SHOULD BRING SCT CONVECTION FOR FRI.
EXTENDED MODELS HINT AT POTENTIAL FOR DAILY CONVECTION CONTINUING
INTO THE WEEKEND ALONG SOUTHER BORDER...BUT OVERALL CONDITIONS
WILL BE MAINLY RAIN-FREE.
TEMPS PEAK MIDWEEK WITH READINGS APPROACHING 90F IN THE SE...AND
EVEN GETTING INTO THE 80S ELSEHERE...EASILY WELL ABOVE NORMAL FOR
THE FIRST WEEK OF SEPT. LOWS WILL ALSO REMAIN QUITE MILD MID/LATE
WEEK AS HIGH HUMIDITY AIR HANGS AROUND. SLIGHTLY COOLER BUT STILL
ABOVE AVERAGE TEMPS WILL CONTINUE THROUGH THE WEEKEND.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
REGIONAL RADAR AT 03Z STILL SHOWING A FEW ISOLATED SHOWERS ACROSS
SOUTHERN PA. LOSS OF HEATING SHOULD CAUSE THE REMAINING SHOWERS TO DISSIPATE
AFTER MIDNIGHT.
FOCUS OVERNIGHT WILL SHIFT TOWARD POTENTIAL OF FOG. LIGHT WIND
AND PTCLDY SKIES SHOULD PROMOTE LOCALLY DENSE VALLEY FOG AFTER
MIDNIGHT ACROSS NORTHERN PA. CLIMATOLOGY AND LATEST SREF/MOS
SUGGEST KBFD IS LIKELY TO EXPERIENCE IFR/LIFR VIS REDUCTIONS LATE
TONIGHT. ALSO...MAY HAVE TO CONTEND WITH DENSE FOG AT KIPT...WHERE
GROUND IS NOW WET FROM A SHOWER EARLIER THIS EVENING. COMPLICATING
FACTOR IS MID LVL CLOUDINESS OVERSPREADING THE SOUTHERN PART OF
THE STATE. FEEL CONFIDENT THESE MID LVL CLOUDS WILL BE THICK
ENOUGH TO DIMINISH THE RADIATIONAL COOLING AND ASSOC DENSE FOG
THREAT ACROSS SOUTHERN PA. HOWEVER...NOT AS CONFIDENT AT KIPT.
ANY AM VALLEY FOG ACROSS NORTHERN PA SHOULD BURN OFF BY LATE AM.
OTHERWISE...WIDESPREAD VFR CONDS AND LIGHT WIND APPEAR VERY
LIKELY MONDAY WITH ONLY ISOLD LATE DAY SHRA/TSRA POSSIBLE...AS
HIGH PRESSURE BUILDS OFF THE MID ATLANTIC COAST.
OUTLOOK...
TUE-FRI...PATCHY AM FOG POSS...MAINLY KBFD. ISOLD PM TSRA IMPACTS
POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/RXR
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
542 AM EDT MON AUG 31 2015
.SYNOPSIS...
A MODERATELY HIGH AMOUNT OF MOISTURE STREAMING EAST FROM THE OHIO
VALLEY WILL EXTEND ACROSS PENN THROUGH MUCH OF THIS WEEK. THE
CLOSE PROXIMITY OF A NEARLY EAST-WEST FRONTAL BOUNDARY ACROSS
PENNSYLAVNAI WILL LEAD TO ISOLATED MAINLY AFTERNOON AND EARLY
EVENING SHRA/TSRA TODAY THROUGH THURSDAY.
HIGH PRESSURE OFF THE EAST COAST WILL RIDGE NORTHWEST INTO
PENNSYLVANIA AND LEAD TO TEMPERATURES WELL ABOVE NORMAL THIS
ENTIRE WEEK. IT WILL FEEL MORE LIKE THE MIDDLE OF SUMMER THAN
SEPTEMBER.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SFC HIGH PRESSURE LOCATED JUST OFF THE SE U.S. COAST WILL SLOWLY
BUILD NORTHWEST...AS AN UPPER RIDGE LOCATED OVER THE UPPER GLAKES
AND MISS VALLEY MOVES EAST TO THE OHIO RIVER VALLEY AND MID
ATLANIC REGION BY 12Z TUES.
925-850 MB THETA-E RIDGE EXTENDS FROM THE OHIO VALLEY...ENE THROUGH
PENN EARLY TODAY...WITH A WEAK/STALLED-OUT SFC FRONT EXTENDING
FROM DETROIT...SW TO ST LOUIS. THE NORTHERN PART OF THIS FRONT
WILL MOVE STEADILY EAST/SOUTHEAST AND BECOME LOCATED ACROSS
CENTRAL PENN THIS EVENING...AND STAY THERE THROUGH MUCH OF
TUESDAY. A BIT OF DRYING WILL BE SEEN ACROSS THE REGION NEAR AND
TO THE NORTH OF INTERSTATE 80.
03Z SREF PROB OF CAPE EXCEEDING 1000 J/KG CLIMBS TO THE 60-80
PERCENT RANGE THIS AFTERNOON...HOWEVER THE PROB OF 2000 J/KG IS
VERY LOW AT 10 PERCENT OR LESS TODAY THROUGH THURSDAY...THUS THE
LOW DIURNAL POP/CVRG FOR CONVECTION. 07Z HRRR CONFIRMS THIS
THINKING AS IT PLACES GENERALLY ISOLATED- SCATTERED/POPCORN LIKE
COVERAGE BETWEEN 17Z-22Z TODAY.
PLENTY OF BKN-OVC ALTO CU /TOPPED BY SOME CIRRUS/ BLANKETED THE
SE HALF TO TWO-THIRDS OF PENN EARLY TODAY...WHILE MOSTLY CLEAR
SKIES AND THE COOLEST TEMPS IN THE L60S WERE FOUND INVOF KBFD.
ELSEWHERE...TEMPS RANGED FROM THE MID 60S TO MID 70S - A RATHER
MUGGY EARLY MORNING FOR THE FINAL DAY OF METEOROLOGICAL SUMMER.
ASIDE FROM A HIGHLY ISOLATED AND BRIEF LIGHT SHOWER OR TWO ON THE
RADAR SCOPE EARLY TODAY...CONDITIONS ACROSS MUCH OF CENTRAL AND
NORTHERN PENN WILL BE DRY WITH A VERY LIGHT AND VARIABLE WIND
THROUGH THE MID MORNING HOURS.
FARTHER SOUTH...WEAK UPPER LOW OVER THE WESTERN CAROLINAS WILL
LIFT NORTHWARD OVERNIGHT ON THE WESTERN PERIPHERY OF THE SPRAWLING
WESTERN ATLANTIC UPPER HIGH CIRCULATION. THIS WILL MAINTAIN THE
FOCUS FOR POOLING MOISTURE AND FORCING FOR SHOWER ACTIVITY THROUGH
THE PRE DAWN HOURS ACROSS MY FAR SOUTH. AGAIN...AREAS TO THE
NORTH SHOULD BE DRY AFTER 06Z AS DEFORMATION LESSENS AND FORCING
FOCUS SHIFTS TO AREAS ALONG AND SOUTH OF MY SOUTHERN TIER.
SOME FOG HAS FORMED...BUT VSBYS ARE HOLDING UP AOA 1 SM
MINS AROUND SUNRISE TODAY WILL RUN IN THE 60S IN PRACTICALLY ALL
LOCATIONS AS DEWPOINTS SHOULD NOT GO ANY LOWER THAN 60F. A FEW OF
THE NORMALLY COLD SPOTS NEAR...AND THE EAST OF KBFD WILL SEE A LOW
TEMP IN THE MID 50S.
HIGH TEMPS THIS AFTERNOON WILL VARY FROM THE U70S OVER THE HIGHEST
ELEVATIONS OF THE NORTH AND WEST...TO THE MID AND UPPER 80S ACROSS
OUR SE ZONES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
TONIGHT SHOULD BE A NEAR REPEAT OF SUNDAY NIGHT/EARLY MONDAY WITH
VARIABLE AMTS OF MAINLY MID AND HIGH CLOUDS AND PERHAPS JUST A
COUPLE SMALL SHOWERS ROAMING THE STREETS.
CONSALL TEMP BLEND YIELDS LOWS AROUND 60F ACROSS THE NRN
MTNS...AND INTHE MID TO UPPER 60S ELSEWHERE.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
ANOMALOUS UPPER LEVEL RIDGE WILL DOMINATE THE OHIO VALLEY AND
EASTERN UNITED STATES MUCH OF THE UPCOMING WEEK...WITH LATEST
GUIDANCE REMAINING FIRM FOR AN EXTENDED RUN OF 850HPA TEMPS
PEAKING DAILY AROUND 16-18C. THIS WILL TRANSLATE TO WELL ABOVE-
NORMAL SFC TEMPS. THIS WARMTH AND INCREASING HUMIDITY SHOULD ALLOW
FOR AT LEAST A SLIGHT CHC FOR DIURNAL CONVECTION EACH DAY...BUT
WARM MID-LEVELS WILL KEEP THE PROBABILITY OF WIDESPREAD RAINFALL
QUITE LOW.
BEST CHANCES FOR PRECIP WILL BE DURING THE MID-LATE WEEK PERIOD
/WED-THU-FRI/ WITH A COUPLE SUBTLE FEATURES. FIRST...A WEAK UPPER
LEVEL WAVE /BEST PROGGED ON THE ECMWF/ SLIPS OVERHEAD ON WED AS
BERMUDA HIGH BRIEFLY RECEDES. AT SAME TIME A WEAK BACKDOOR COLD
FRONT SLIPS SOUTHWARD OFF THE EAST COAST. THIS COULD HELP POOL
SOME LOW LEVEL MOISTURE OVER THE MID ATLANTIC AND OHIO VALLEY AS
MID LEVELS COOL JUST A BIT...BRINGING POTENTIAL FOR SCT TSTMS.
RIDGE BUILDS BACK IN FOR FRI...BUT ANOTHER SURFACE BACKDOOR FRONT
TRIES TO SLIP ACROSS THE STATE AS SURFACE HIGH EXPANDS IN FROM THE
NORTH. THIS BOUNDARY SHOULD BRING SCT CONVECTION FOR FRI.
EXTENDED MODELS HINT AT POTENTIAL FOR DAILY CONVECTION CONTINUING
INTO THE WEEKEND ALONG SOUTHER BORDER...BUT OVERALL CONDITIONS
WILL BE MAINLY RAIN-FREE.
TEMPS PEAK MIDWEEK WITH READINGS APPROACHING 90F IN THE SE...AND
EVEN GETTING INTO THE 80S ELSEHERE...EASILY WELL ABOVE NORMAL FOR
THE FIRST WEEK OF SEPT. LOWS WILL ALSO REMAIN QUITE MILD MID/LATE
WEEK AS HIGH HUMIDITY AIR HANGS AROUND. SLIGHTLY COOLER BUT STILL
ABOVE AVERAGE TEMPS WILL CONTINUE THROUGH THE WEEKEND.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
REGIONAL RADAR AT 03Z STILL SHOWING A FEW ISOLATED SHOWERS ACROSS
SOUTHERN PA. LOSS OF HEATING SHOULD CAUSE THE REMAINING SHOWERS TO DISSIPATE
AFTER MIDNIGHT.
FOCUS OVERNIGHT WILL SHIFT TOWARD POTENTIAL OF FOG. LIGHT WIND
AND PTCLDY SKIES SHOULD PROMOTE LOCALLY DENSE VALLEY FOG AFTER
MIDNIGHT ACROSS NORTHERN PA. CLIMATOLOGY AND LATEST SREF/MOS
SUGGEST KBFD IS LIKELY TO EXPERIENCE IFR/LIFR VIS REDUCTIONS LATE
TONIGHT. ALSO...MAY HAVE TO CONTEND WITH DENSE FOG AT KIPT...WHERE
GROUND IS NOW WET FROM A SHOWER EARLIER THIS EVENING. COMPLICATING
FACTOR IS MID LVL CLOUDINESS OVERSPREADING THE SOUTHERN PART OF
THE STATE. FEEL CONFIDENT THESE MID LVL CLOUDS WILL BE THICK
ENOUGH TO DIMINISH THE RADIATIONAL COOLING AND ASSOC DENSE FOG
THREAT ACROSS SOUTHERN PA. HOWEVER...NOT AS CONFIDENT AT KIPT.
ANY AM VALLEY FOG ACROSS NORTHERN PA SHOULD BURN OFF BY LATE AM.
OTHERWISE...WIDESPREAD VFR CONDS AND LIGHT WIND APPEAR VERY
LIKELY MONDAY WITH ONLY ISOLD LATE DAY SHRA/TSRA POSSIBLE...AS
HIGH PRESSURE BUILDS OFF THE MID ATLANTIC COAST.
OUTLOOK...
TUE-FRI...PATCHY AM FOG POSS...MAINLY KBFD. ISOLD PM TSRA IMPACTS
POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/RXR
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
529 AM EDT MON AUG 31 2015
.SYNOPSIS...
A MODERATELY HIGH AMOUNT OF MOISTURE STREAMING EAST FROM THE OHIO
VALLEY WILL EXTEND ACROSS PENN THROUGH MUCH OF THIS WEEK. THE
CLOSE PROXIMITY OF A NEARLY EAST-WEST FRONTAL BOUNDARY ACROSS
PENNSYLAVNAI WILL LEAD TO ISOLATED MAINLY AFTERNOON AND EARLY
EVENING SHRA/TSRA TODAY THROUGH THURSDAY.
HIGH PRESSURE OFF THE EAST COAST WILL RIDGE NORTHWEST INTO
PENNSYLVANIA AND LEAD TO TEMPERATURES WELL ABOVE NORMAL THIS
ENTIRE. IT WILL FEEL MORE LIKE THE MIDDLE OF SUMMER THAN
SEPTEMBER.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SFC HIGH PRESSURE LOCATED JUST OFF THE SE U.S. COAST WILL SLOWLY
BUILD NORTHWEST AS AN UPPER RIDGE LOCATED OVER THE UPPER GLAKES
AND MISS VALLEY MOVES EAST TO THE OHIO RIVER VALLEY AND MID
ATLANIC REGION BY 12Z TUES.
925-850 MB THETA-E RIDGE EXTENDS FROM THE OHIO VALLEY...ENE THROUGH
PENN EARLY TODAY...WITH A WEAK...STALLED-OUT SFC FRONT EXTENDING
FROM DETROIT...SW TO ST LOUIS. THE NORTHERN PORTIONS OF THIS FRONT
WILL MOVE STEADILY EAST/SOUTHEAST AND BECOME LOCATED ACROSS
CENTRAL PENN THIS EVENING...THROUGH MUCH OF TUESDAY. A BIT OF
DRYING WILL BE SEEN ACROSS THE REGION NEAR AND TO THE NORTH OF
INTERSTATE 80.
03Z SREF PROB OF CAPE EXCEEDING 2000 J/KG IS VERY LOW AT 10
PERCENT OR LESS TODAY THROUGH THURSDAY...THUS THE LOW DIURNAL
POP/CVRG FOR CONVECTION. 07Z HRRR CONFIRMS THIS THINKING AS IT
PLACES GENERALLY ISOLATED-SCATTERED/POPCORN LIKE COVERAGE BETWEEN
17Z-22Z TODAY.
PLENTY OF BKN-OVC ALTO CU /TOPPED BY SOME CIRRUS/ BLANKETED THE
SE HALF TO TWO-THIRDS OF PENN EARLY TODAY...WHILE MOSTLY CLEAR
SKIES AND THE COOLEST TEMPS IN THE L60S WERE FOUND INVOF KBFD.
ELSEWHERE...TEMPS RANGED FROM THE MID 60S TO MID 70S - A RATHER
MUGGY EARLY MORNING FOR THE FINAL DAY OF METEOROLOGICAL SUMMER.
ASIDE FROM A HIGHLY ISOLATED AND BRIEF LIGHT SHOWER OR TWO ON THE
RADAR SCOPE EARLY TODAY...CONDITIONS ACROSS MUCH OF CENTRAL AND
NORTHERN PENN WILL BE DRY WITH A VERY LIGHT AND VARIABLE WIND
THROUGH THE MID MORNING HOURS.
FARTHER SOUTH...WEAK UPPER LOW OVER THE WESTERN CAROLINAS WILL
LIFT NORTHWARD OVERNIGHT ON THE WESTERN PERIPHERY OF THE SPRAWLING
WESTERN ATLANTIC UPPER HIGH CIRCULATION. THIS WILL MAINTAIN THE
FOCUS FOR POOLING MOISTURE AND FORCING FOR SHOWER ACTIVITY THROUGH
THE PRE DAWN HOURS ACROSS MY FAR SOUTH. AGAIN...AREAS TO THE
NORTH SHOULD BE DRY AFTER 06Z AS DEFORMATION LESSENS AND FORCING
FOCUS SHIFTS TO AREAS ALONG AND SOUTH OF MY SOUTHERN TIER.
SOME FOG HAS FORMED...BUT VSBYS ARE HOLDING UP AOA 1 SM
MINS AROUND SUNRISE TODAY WILL RUN IN THE 60S IN PRACTICALLY ALL
LOCATIONS AS DEWPOINTS SHOULD NOT GO ANY LOWER THAN 60F. A FEW OF
THE NORMALLY COLD SPOTS NEAR...AND THE EAST OF KBFD WILL SEE A LOW
TEMP IN THE MID 50S.
HIGH TEMPS THIS AFTERNOON WILL VARY FROM THE U70S OVER THE HIGHEST
ELEVATIONS OF THE NORTH AND WEST...TO THE MID AND UPPER 80S ACROSS
OUR SE ZONES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
TONIGHT SHOULD BE A NEAR REPEAT OF SUNDAY NIGHT/EARLY MONDAY WITH
VARIABLE AMTS OF MAINLY MID AND HIGH CLOUDS AND PERHAPS JUST A
COUPLE SMALL SHOWERS ROAMING THE STREETS.
CONSALL TEMP BLEND YIELDS LOWS AROUND 60F ACROSS THE NRN
MTNS...AND INTHE MID TO UPPER 60S ELSEWHERE.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
ANOMALOUS UPPER LEVEL RIDGE WILL DOMINATE THE OHIO VALLEY AND
EASTERN UNITED STATES MUCH OF THE UPCOMING WEEK...WITH LATEST
GUIDANCE REMAINING FIRM FOR AN EXTENDED RUN OF 850HPA TEMPS
PEAKING DAILY AROUND 16-18C. THIS WILL TRANSLATE TO WELL ABOVE-
NORMAL SFC TEMPS. THIS WARMTH AND INCREASING HUMIDITY SHOULD ALLOW
FOR AT LEAST A SLIGHT CHC FOR DIURNAL CONVECTION EACH DAY...BUT
WARM MID-LEVELS WILL KEEP THE PROBABILITY OF WIDESPREAD RAINFALL
QUITE LOW.
BEST CHANCES FOR PRECIP WILL BE MIDWEEK /WED-THU-FRI/ WITH A
COUPLE SUBTLE FEATURES. FIRST...A WEAK UPPER LEVEL WAVE /BEST
PROGGED ON THE ECMWF/ SLIPS OVERHEAD ON WED AS BERMUDA HIGH
BRIEFLY RECEDES. AT SAME TIME A WEAK BACKDOOR COLD FRONT SLIPS
SOUTHWARD OFF THE EAST COAST. THIS COULD HELP POOL SOME LOW LEVEL
MOISTURE OVER THE MID ATLANTIC AND OHIO VALLEY AS MID LEVELS COOL
JUST A BIT...BRINGING POTENTIAL FOR SCT TSTMS. RIDGE BUILDS BACK
IN FOR FRI...BUT ANOTHER SURFACE BACKDOOR FRONT TRIES TO SLIP
ACROSS THE STATE AS SURFACE HIGH EXPANDS IN FROM THE NORTH. THIS
BOUNDARY SHOULD BRING SCT CONVECTION FOR FRI.
EXTENDED MODELS HINT AT POTENTIAL FOR DAILY CONVECTION CONTINUING
INTO THE WEEKEND ALONG SOUTHER BORDER...BUT OVERALL CONDITIONS
WILL BE MAINLY RAIN-FREE.
TEMPS PEAK MIDWEEK WITH READINGS APPROACHING 90F IN THE SE...AND
EVEN GETTING INTO THE 80S ELSEHERE...EASILY WELL ABOVE NORMAL FOR
THE FIRST WEEK OF SEPT. LOWS WILL ALSO REMAIN QUITE MILD MID/LATE
WEEK AS HIGH HUMIDITY AIR HANGS AROUND. SLIGHTLY COOLER BUT STILL
ABOVE AVERAGE TEMPS WILL CONTINUE THROUGH THE WEEKEND.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
REGIONAL RADAR AT 03Z STILL SHOWING A FEW ISOLATED SHOWERS ACROSS
SOUTHERN PA. LOSS OF HEATING SHOULD CAUSE THE REMAINING SHOWERS TO DISSIPATE
AFTER MIDNIGHT.
FOCUS OVERNIGHT WILL SHIFT TOWARD POTENTIAL OF FOG. LIGHT WIND
AND PTCLDY SKIES SHOULD PROMOTE LOCALLY DENSE VALLEY FOG AFTER
MIDNIGHT ACROSS NORTHERN PA. CLIMATOLOGY AND LATEST SREF/MOS
SUGGEST KBFD IS LIKELY TO EXPERIENCE IFR/LIFR VIS REDUCTIONS LATE
TONIGHT. ALSO...MAY HAVE TO CONTEND WITH DENSE FOG AT KIPT...WHERE
GROUND IS NOW WET FROM A SHOWER EARLIER THIS EVENING. COMPLICATING
FACTOR IS MID LVL CLOUDINESS OVERSPREADING THE SOUTHERN PART OF
THE STATE. FEEL CONFIDENT THESE MID LVL CLOUDS WILL BE THICK
ENOUGH TO DIMINISH THE RADIATIONAL COOLING AND ASSOC DENSE FOG
THREAT ACROSS SOUTHERN PA. HOWEVER...NOT AS CONFIDENT AT KIPT.
ANY AM VALLEY FOG ACROSS NORTHERN PA SHOULD BURN OFF BY LATE AM.
OTHERWISE...WIDESPREAD VFR CONDS AND LIGHT WIND APPEAR VERY
LIKELY MONDAY WITH ONLY ISOLD LATE DAY SHRA/TSRA POSSIBLE...AS
HIGH PRESSURE BUILDS OFF THE MID ATLANTIC COAST.
OUTLOOK...
TUE-FRI...PATCHY AM FOG POSS...MAINLY KBFD. ISOLD PM TSRA IMPACTS
POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/RXR
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1109 AM MDT MON AUG 31 2015
.UPDATE...
ISSUED AT 852 AM MDT MON AUG 31 2015
UPPER WAVE CONTINUES TO PUSH THROUGH THE NORTHERN PLAINS. RADAR
STILL INDICATES SHOWER ACTIVITY BEHIND THE COLD FRONT ACROSS
SOUTHWEST INTO CENTRAL SD. ADDED SOME ISOLATED SHOWERS THROUGH
THE DAY FOR ANY RAIN THAT MIGHT BE REACHING THE GROUND...ALTHOUGH
OBS STILL SHOW PRETTY DRY AIR SO IT MAY REMAIN VIRGA. INCREASED
CLOUD COVER TO REFLECT CURRENT TRENDS...BUT REST OF FORECAST LOOKS
ON TRACK FOR NOW.
&&
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
ISSUED AT 327 AM MDT MON AUG 31 2015
WATER VAPOR IMAGERY SHOWS STRONG UPPER WAVE CROSSING CNTRL TO ERN MT
INTO NRN WY. SURFACE ANALYSIS SHOWS LOW PRES ACROSS THE WRN/CNTRL
DAKOTAS AHEAD OF THE UPPER WAVE...WITH A COLD FRONT QUICKLY PUSHING
THRU ERN MT/CNTRL WY TOWARD THE CWA. TEMPS ACROSS THE CWA ARE IN THE
60S/70S...EVEN 80S ACROSS THE DOWNSLOPING N/NE BLKHLS. BEHIND THE
FRONT...OBS SHOWING TEMPS DROPPING INTO THE 50S WITH WINDS OF 15 TO
30 GUSTING TO 30 TO 40 MPH. RADAR SHOWS SHOWER ACTIVITY CROSSING WRN
SD...HOWEVER NEARLY ALL THE PRECIP IS VIRGA WITH LITTLE TO NO RAIN
REACHING THE GROUND. THE COLD FRONT WILL PUSH THROUGH NE WY TO WRN
SD IN THE NEXT 4/5 HOURS OR SO...AND CLEAR SCNTRL SD BY MID TO LATE
MORNING. HRRR SUGGESTS WINDS WILL GENERALLY BE 15 TO 25 MPH WITH
GUSTS TO 30 TO 40 MPH...BUT IS ALSO SHOWING STRONGER WINDS ACROSS
THE WRN SD PLAINS NORTH AND EAST OF THE BLKHLS. WIND ADVISORY
CRITERIA WINDS ARE EXPECTED...HOWEVER JUST FOR COUPLE HOURS OR SO
IMMEDIATELY AFTER THE FROPA. COULD SEE LINGERING SHRA ACTIVITY EARLY
THIS MORNING AS MODELS ARE HAVING A HARD TIME DECIDING HOW MUCH
PRECIP WILL REACH THE GROUND. WILL LEAN TOWARD A DRY FORECAST FOR
NOW CONSIDERING THE LATEST RADAR IMAGERY...BUT WILL REASSESS CLOSER
TO 12Z. OTHERWISE A DRY DAY IS EXPECTED WITH MUCH COOLER
TEMPERATURES AND CLEARING SKIES. HIGHS WILL REACH THE UPPER 70S TO
UPPER 80S. TEMPS TONIGHT WILL DROP INTO THE 50S TO LOWER 60S. RETURN
FLOW WILL SET UP BY MON NIGHT/TUE MRNG WITH WARMER TEMPS
EXPECTED. HIGHS WILL RETURN TO THE MID 80S TO MID 90S. DRY WEATHER
WILL CONTINUE TUE/TUE NIGHT WITH BROAD SWRLY FLOW ALOFT
PERSISTING.
.LONG TERM...WEDNESDAY THROUGH SUNDAY
ISSUED AT 327 AM MDT MON AUG 31 2015
THE UPPER TROUGH WILL REMAIN OVER THE NORTH AMERICAN PACIFIC
COAST THROUGH MOST OF THE WEEK...EVENTUALLY MOVING INLAND BY THE
WEEKEND AS ANOTHER IMPULSE DROPS INTO THE UPPER TROUGH FROM THE
NORTHWEST. THIS PATTERN WILL LEAD TO CONTINUED VERY WARM
TEMPERATURES OVER THE NORTHERN PLAINS BOTH WEDNESDAY AND THURSDAY.
FRIDAY AND SATURDAY WILL BE SLIGHTLY COOLER...WITH MUCH COOLER
TEMPS ON SUNDAY AND MONDAY BEHIND A RELATIVELY STRONG COLD FRONT
WHICH WILL PASS THROUGH THE AREA EARLY SUNDAY. DRY WEATHER IS
EXPECTED ON WEDNESDAY AND THURSDAY WITH A CHANCE OF THUNDERSTORMS
EACH DAY FROM FRIDAY THROUGH THE WEEKEND AS A SERIES OF UPPER
IMPULSES CROSS THE REGION AND COOLER AIR FLOWS IN AT THE SFC.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY)
ISSUED AT 1105 AM MDT MON AUG 31 2015
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. A NARROW BAND OF -SHRA
WILL MOVE ACROSS SCNTRL SD THROUGH THIS AFTN. GUSTY NORTHWEST
WINDS ACROSS THE SD PLAINS WILL DIMINISH THIS AFTN.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...POJORLIE
SHORT TERM...13
LONG TERM...10
AVIATION...BUNKERS
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
859 AM MDT MON AUG 31 2015
.UPDATE...
ISSUED AT 852 AM MDT MON AUG 31 2015
UPPER WAVE CONTINUES TO PUSH THROUGH THE NORTHERN PLAINS. RADAR
STILL INDICATES SHOWER ACTIVITY BEHIND THE COLD FRONT ACROSS
SOUTHWEST INTO CENTRAL SD. ADDED SOME ISOLATED SHOWERS THROUGH
THE DAY FOR ANY RAIN THAT MIGHT BE REACHING THE GROUND...ALTHOUGH
OBS STILL SHOW PRETTY DRY AIR SO IT MAY REMAIN VIRGA. INCREASED
CLOUD COVER TO REFLECT CURRENT TRENDS...BUT REST OF FORECAST LOOKS
ON TRACK FOR NOW.
&&
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
ISSUED AT 327 AM MDT MON AUG 31 2015
WATER VAPOR IMAGERY SHOWS STRONG UPPER WAVE CROSSING CNTRL TO ERN MT
INTO NRN WY. SURFACE ANALYSIS SHOWS LOW PRES ACROSS THE WRN/CNTRL
DAKOTAS AHEAD OF THE UPPER WAVE...WITH A COLD FRONT QUICKLY PUSHING
THRU ERN MT/CNTRL WY TOWARD THE CWA. TEMPS ACROSS THE CWA ARE IN THE
60S/70S...EVEN 80S ACROSS THE DOWNSLOPING N/NE BLKHLS. BEHIND THE
FRONT...OBS SHOWING TEMPS DROPPING INTO THE 50S WITH WINDS OF 15 TO
30 GUSTING TO 30 TO 40 MPH. RADAR SHOWS SHOWER ACTIVITY CROSSING WRN
SD...HOWEVER NEARLY ALL THE PRECIP IS VIRGA WITH LITTLE TO NO RAIN
REACHING THE GROUND. THE COLD FRONT WILL PUSH THROUGH NE WY TO WRN
SD IN THE NEXT 4/5 HOURS OR SO...AND CLEAR SCNTRL SD BY MID TO LATE
MORNING. HRRR SUGGESTS WINDS WILL GENERALLY BE 15 TO 25 MPH WITH
GUSTS TO 30 TO 40 MPH...BUT IS ALSO SHOWING STRONGER WINDS ACROSS
THE WRN SD PLAINS NORTH AND EAST OF THE BLKHLS. WIND ADVISORY
CRITERIA WINDS ARE EXPECTED...HOWEVER JUST FOR COUPLE HOURS OR SO
IMMEDIATELY AFTER THE FROPA. COULD SEE LINGERING SHRA ACTIVITY EARLY
THIS MORNING AS MODELS ARE HAVING A HARD TIME DECIDING HOW MUCH
PRECIP WILL REACH THE GROUND. WILL LEAN TOWARD A DRY FORECAST FOR
NOW CONSIDERING THE LATEST RADAR IMAGERY...BUT WILL REASSESS CLOSER
TO 12Z. OTHERWISE A DRY DAY IS EXPECTED WITH MUCH COOLER
TEMPERATURES AND CLEARING SKIES. HIGHS WILL REACH THE UPPER 70S TO
UPPER 80S. TEMPS TONIGHT WILL DROP INTO THE 50S TO LOWER 60S. RETURN
FLOW WILL SET UP BY MON NIGHT/TUE MRNG WITH WARMER TEMPS
EXPECTED. HIGHS WILL RETURN TO THE MID 80S TO MID 90S. DRY WEATHER
WILL CONTINUE TUE/TUE NIGHT WITH BROAD SWRLY FLOW ALOFT
PERSISTING.
.LONG TERM...WEDNESDAY THROUGH SUNDAY
ISSUED AT 327 AM MDT MON AUG 31 2015
THE UPPER TROUGH WILL REMAIN OVER THE NORTH AMERICAN PACIFIC
COAST THROUGH MOST OF THE WEEK...EVENTUALLY MOVING INLAND BY THE
WEEKEND AS ANOTHER IMPULSE DROPS INTO THE UPPER TROUGH FROM THE
NORTHWEST. THIS PATTERN WILL LEAD TO CONTINUED VERY WARM
TEMPERATURES OVER THE NORTHERN PLAINS BOTH WEDNESDAY AND THURSDAY.
FRIDAY AND SATURDAY WILL BE SLIGHTLY COOLER...WITH MUCH COOLER
TEMPS ON SUNDAY AND MONDAY BEHIND A RELATIVELY STRONG COLD FRONT
WHICH WILL PASS THROUGH THE AREA EARLY SUNDAY. DRY WEATHER IS
EXPECTED ON WEDNESDAY AND THURSDAY WITH A CHANCE OF THUNDERSTORMS
EACH DAY FROM FRIDAY THROUGH THE WEEKEND AS A SERIES OF UPPER
IMPULSES CROSS THE REGION AND COOLER AIR FLOWS IN AT THE SFC.
&&
.AVIATION...FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING
ISSUED AT 327 AM MDT MON AUG 31 2015
BREEZY NORTHWEST WINDS WILL FOLLOW A COLD FRONT THIS MORNING. VFR
CONDITIONS ARE EXPECTED TODAY AND TONIGHT.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...POJORLIE
SHORT TERM...13
LONG TERM...10
AVIATION...10
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
328 AM MDT MON AUG 31 2015
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT
ISSUED AT 327 AM MDT MON AUG 31 2015
WATER VAPOR IMAGERY SHOWS STRONG UPPER WAVE CROSSING CNTRL TO ERN MT
INTO NRN WY. SURFACE ANALYSIS SHOWS LOW PRES ACROSS THE WRN/CNTRL
DAKOTAS AHEAD OF THE UPPER WAVE...WITH A COLD FRONT QUICKLY PUSHING
THRU ERN MT/CNTRL WY TOWARD THE CWA. TEMPS ACROSS THE CWA ARE IN THE
60S/70S...EVEN 80S ACROSS THE DOWNSLOPING N/NE BLKHLS. BEHIND THE
FRONT...OBS SHOWING TEMPS DROPPING INTO THE 50S WITH WINDS OF 15 TO
30 GUSTING TO 30 TO 40 MPH. RADAR SHOWS SHOWER ACTIVITY CROSSING WRN
SD...HOWEVER NEARLY ALL THE PRECIP IS VIRGA WITH LITTLE TO NO RAIN
REACHING THE GROUND. THE COLD FRONT WILL PUSH THROUGH NE WY TO WRN
SD IN THE NEXT 4/5 HOURS OR SO...AND CLEAR SCNTRL SD BY MID TO LATE
MORNING. HRRR SUGGESTS WINDS WILL GENERALLY BE 15 TO 25 MPH WITH
GUSTS TO 30 TO 40 MPH...BUT IS ALSO SHOWING STRONGER WINDS ACROSS
THE WRN SD PLAINS NORTH AND EAST OF THE BLKHLS. WIND ADVISORY
CRITERIA WINDS ARE EXPECTED...HOWEVER JUST FOR COUPLE HOURS OR SO
IMMEDIATELY AFTER THE FROPA. COULD SEE LINGERING SHRA ACTIVITY EARLY
THIS MORNING AS MODELS ARE HAVING A HARD TIME DECIDING HOW MUCH
PRECIP WILL REACH THE GROUND. WILL LEAN TOWARD A DRY FORECAST FOR
NOW CONSIDERING THE LATEST RADAR IMAGERY...BUT WILL REASSESS CLOSER
TO 12Z. OTHERWISE A DRY DAY IS EXPECTED WITH MUCH COOLER
TEMPERATURES AND CLEARING SKIES. HIGHS WILL REACH THE UPPER 70S TO
UPPER 80S. TEMPS TONIGHT WILL DROP INTO THE 50S TO LOWER 60S. RETURN
FLOW WILL SET UP BY MON NGHT/TUE MRNG WITH WARMER TEMPS EXPECTED.
HIGHS WILL RETURN TO THE MID 80S TO MID 90S. DRY WEATHER WILL
CONTINUE TUE/TUE NGHT WITH BROAD SWRLY FLOW ALOFT PERSISTING.
.LONG TERM...WEDNESDAY THROUGH SUNDAY
ISSUED AT 327 AM MDT MON AUG 31 2015
THE UPPER TROUGH WILL REMAIN OVER THE NORTH AMERICAN PACIFIC
COAST THROUGH MOST OF THE WEEK...EVENTUALLY MOVING INLAND BY THE
WEEKEND AS ANOTHER IMPULSE DROPS INTO THE UPPER TROUGH FROM THE
NORTHWEST. THIS PATTERN WILL LEAD TO CONTINUED VERY WARM
TEMPERATURES OVER THE NORTHERN PLAINS BOTH WEDNESDAY AND THURSDAY.
FRIDAY AND SATURDAY WILL BE SLIGHTLY COOLER...WITH MUCH COOLER
TEMPS ON SUNDAY AND MONDAY BEHIND A RELATIVELY STRONG COLD FRONT
WHICH WILL PASS THROUGH THE AREA EARLY SUNDAY. DRY WEATHER IS
EXPECTED ON WEDNESDAY AND THURSDAY WITH A CHANCE OF THUNDERSTORMS
EACH DAY FROM FRIDAY THROUGH THE WEEKEND AS A SERIES OF UPPER
IMPULSES CROSS THE REGION AND COOLER AIR FLOWS IN AT THE SFC.
&&
.AVIATION...FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING
ISSUED AT 327 AM MDT MON AUG 31 2015
BREEZY NORTHWEST WINDS WILL FOLLOW A COLD FRONT THIS MORNING. VFR
CONDITIONS ARE EXPECTED TODAY AND TONIGHT.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...13
LONG TERM...10
AVIATION...10
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1052 AM CDT MON AUG 31 2015
.UPDATE...
EARLIER FOG THIS MORNING HAS DISSIPATED WITH TEMPERATURES NOW INTO
THE UPPER 70S AND LOWER 80S. LATEST MODELS INCLUDING THE HRRR SHOW
LITTLE IN THE WAY OF CONVECTION TODAY...WITH BEST CHANCES OVER THE
SOUTHEAST THIRD OF THE CWA. ALTHOUGH CANNOT RULE OUT AN ISOLATED
STORM OR TWO ANYWHERE...WILL TRIM POPS BACK TO SOUTHERN AND
EASTERN ZONES FOR THIS AFTERNOON. REST OF FORECAST INCLUDING HIGH
TEMPS LOOKS GOOD.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 615 AM CDT MON AUG 31 2015/
AVIATION UPDATE...FOR 12Z TAF`S.
BNA/CKV/CSV...MORNING RADIATION FOG AT CKV & CSV SHOULD DISSIPATE
BY 14Z. HIGH PRESSURE CONTINUES TO BUILD INTO THE MID STATE FROM
THE NORTHEAST, WITH DRIER AIR NOW IN PLACE AND GREATLY REDUCED
POP`S. THERE MAY BE A STRAY ECHO OR TWO DURING THE AFTERNOON, BUT
WON`T MENTION PRECIP IN THE TAF`S. EXPECT FULL RADIATIONAL COOLING
AGAIN OVERNIGHT, SO FOG WILL MORE THAN LIKELY BECOME AN ISSUE.
PREV DISCUSSION... /ISSUED 300 AM CDT MON AUG 31 2015/
DISCUSSION...
AFTER A FEW SHOWERS AND THUNDERSTORMS YESTERDAY AFTERNOON THINGS
HAVE QUIETED DOWN CONSIDERABLY ACROSS MIDDLE TN. PARTLY TO MOSTLY
CLOUDY SKIES ARE BEING SEEN ACROSS THE AREA AND A FEW FOLKS ARE
EXPERIENCING PATCHY DENSE FOG...ESPECIALLY THOSE WHO SAW RAIN
YESTERDAY. THIS FOG WILL PERSIST UNTIL A COUPLE HOURS AFTER SUNRISE
THIS MORNING SO BE CAUTIOUS WHEN YOU HEAD OUT FOR THE MONDAY MORNING
COMMUTE AS SOME VISIBILITIES ARE BELOW 1 MILE.
BEYOND THIS MORNING`S FOG WE ARE IN FOR A FAIRLY STAGNANT PATTERN
OVER THE NEXT SEVERAL DAYS. WEAK RIDGING ALOFT WILL SETTLE IN AND
WITHOUT MUCH IN THE WAY OF RETURN FLOW...NOR A PUSH OF DRY AIR FROM
THE NORTH...DEW POINTS WILL REMAIN THE SAME THROUGHOUT THE WEEK AND
TEMPERATURES WILL WARM A DEGREE OR TWO EACH AFTERNOON. RAIN CHANCES
WILL BE LOW EACH AFTERNOON...BUT NOT ZERO...AS THERE WILL BE JUST
ENOUGH LOW LEVEL MOISTURE TO FEED A COUPLE OF STORMS EACH DAY.
COVERAGE WILL ALMOST BE NEGLIGIBLE.
OUR NEXT SHOT AT ANY SIGNIFICANT RAIN MIGHT BE OVER THE LABOR DAY
WEEKEND. WHILE THERE WON`T BE ANY FRONTAL PASSAGE...THE RIDGE ALOFT
FROM DURING THE WEEK MAY BEGIN TO BREAK DOWN AND GIVE US SOME
GENERAL TROUGHINESS OVER THE SOUTHEAST. THIS WON`T INCREASE POPS A
GREAT DEAL...BUT IT SHOULD OPEN THE DOOR FOR SLIGHTLY BETTER
COVERAGE SATURDAY AND SUNDAY AFTERNOONS. WHILE POPS MIGHT INCREASE A
LITTLE FOR THE UPCOMING HOLIDAY WEEKEND...IT DEFINITELY WON`T BE A
WASHOUT.
EXTENDED RANGE GUIDANCE IS ACTUALLY IN DECENT AGREEMENT ABOUT A
DIFFUSE FRONT TRYING TO PUSH INTO THE REGION AFTER LABOR DAY...SO
IT MAY BE AWHILE BEFORE ANY WIDESPREAD RAINS RETURNS TO THE
FORECAST.
UNGER
AVIATION...
06Z TAF DISCUSSION.
EARLIER SHOWERS HAVE DISSIPATED AND MUCH OF THE CLOUD COVER
OVERHEAD IS THINNING OUT. ONLY EXCEPTION IS CLOSER TO THE PLATEAU
AND THUS CSV WHERE A WEAK UPPER LOW IS LOCATED. CLOUD COVER AND
ISOLATED SHRA FROM THAT COULD STILL AFFECT CSV THROUGH ROUGHLY
12Z AS THE UPPER LOW PUSHES NORTHWARD INTO KY.
OTHERWISE...PARTIAL CLEARING AND AMPLE LOW LEVEL MOISTURE SHOULD
LEAD TO LIGHT FOG ACROSS MIDDLE TN. LOWEST VSBYS...AT TIMES BELOW
1 SM...SHOULD BE LOCATED AT CKV AND CSV FROM 07-13Z WHERE RAIN
FELL EARLIER TODAY. ONCE THE FOG BURNS OFF MID-MORNING
MONDAY...VFR CONDITIONS ARE EXPECTED THRU 06Z TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 88 68 91 70 / 10 10 20 10
CLARKSVILLE 87 66 90 68 / 10 10 20 0
CROSSVILLE 81 65 84 67 / 20 10 20 10
COLUMBIA 86 66 90 68 / 10 10 20 0
LAWRENCEBURG 85 67 89 68 / 20 10 20 10
WAVERLY 87 67 90 69 / 10 10 20 0
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
55
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
338 PM CDT MON AUG 31 2015
.SHORT TERM...
(Tonight and Tuesday)
The afternoon cumulus field development is well underway. The TTU
WRF and HRRR models continue to suggest isolated convection will
develop across the southeast third of the forecast area, or roughly
south and east of a Sonora to Eden to Brownwood line during the next
few hours, with any convection dissipating after sunset.
Temperatures dropped to near 60 degrees last night in low-lying
areas under clear skies and light winds. Given the dry soil
conditions in place with similar conditions expected tonight, we
went a couple degrees under guidance to account for this. Sunny
skies and afternoon cumulus are expected for Tuesday, with high
temperatures similar to today, generally in the lower to mid 90s.
.LONG TERM...
(Wednesday through Tuesday)
Weak upper level ridge in place across the area will gradually
strengthen across West Central Texas through the period. Low level
thickness and temperature fields are not forecasted by the models
to climb nearly as high as when the last upper level ridge was in
place, but still should be strong enough to keep temperatures at or
a few degrees above normal for the entire extended. Ridge really
nor forecasted to budge much through the entire first 10 days of
September, so it looks like a quiet extended forecast will
continue.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 69 94 71 94 / 0 5 0 0
San Angelo 69 95 70 95 / 5 5 5 5
Junction 67 93 69 91 / 10 5 5 5
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Doll/07
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1235 PM CDT MON AUG 31 2015
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...SHOWER AND THUNDERSTORM ACTIVITY BEGINNING TO POP UP
NEAR KBRO AND KHRL...WITH SOME WELL-DEFINED LOWERED CIGS IN THEIR
WAKE. ACTIVITY WILL SPREAD INLAND...REACHING KMFE LATER THIS
AFTERNOON. MADE MINOR TWEAKS TO SKY COVER...BUT OTHERWISE CLOUD
AND SHOWER WORDING REMAINS THE SAME. LOW CLOUDS SHOULD BREAK UP
THIS EVENING WHILE WINDS DECREASE TO AROUND 5KTS. A FEW SHOWERS
MAY AGAIN DRIFT NORTHWARD ACROSS KBRO AND MAYBE KHRL JUST BEFORE
DAWN...SIMILAR TO TODAY.
&&
.PREV DISCUSSION... /ISSUED 637 AM CDT MON AUG 31 2015/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...CURRENT RADAR SHOWS CONVECTION MOVING ASHORE FROM THE
GULF WATERS AND HAS IMPACTED BRO RECENTLY WITH ANOTHER BAND ON THE
MOVE TOWARDS THE LOWER VALLEY. CONVECTION WILL INCREASE IN
COVERAGE TODAY WITH A GOOD POSSIBILITY OF THE AERODROMES
EXPERIENCING SHOWERS AND STORMS TODAY. EXPECT TEMPO MVFR CONDS AND
POSSIBLY HIGH IFR UNDER THE STRONGER STORMS. CONVECTION WILL END
THIS EVENING.
PREV DISCUSSION... /ISSUED 358 AM CDT MON AUG 31 2015/
SHORT TERM /TODAY THROUGH TUESDAY/...FORECAST CHALLENGE FOR THE SHORT
TERM WILL BE PRECIPITATION CHANCES AND PLACEMENT.
EARLY MORNING WATER VAPOR IMAGERY DEPICTS A MID LEVEL LOW PRESSURE
AREA SPINNING NICELY ACROSS SOUTH CENTRAL TEXAS WITH A FINGER OF DRY
AIR ADVECTING INTO TO THE WESTERN CWA ON THE SOUTHSIDE OF THIS
FEATURE. TIME HEIGHTS SHOW THIS DRY AIR NICELY IN THE 600-400MB
LAYER. THIS LOW PRESSURE AREA IS LOCATED WITHIN A BROAD TROUGH
EXTENDING FROM NORTHEAST MEXICO NORTHEASTWARD THROUGH EASTERN
ARKANSAS. PWAT ON THE 00Z BRO SOUNDING WAS 1.93 INCHES WITH EVEN
HIGHER PWATS SOUTHWARD INTO THE BAY OF CAMPECHE ACCORDING TO BLENDED
TPW PRODUCTS. AT THIS HOUR CONVECTION IN THE GULF IS INCREASING
AHEAD OF DEEPER MOISTURE AND LARGE SCALE LIFT.
TROUGH AXIS WILL MOVE SLOWLY EASTWARD TODAY FROM ITS PRESENT
LOCATION LEAVING THE AREA IN FAVORABLE LARGE SCALE LIFT. MID LEVEL
DRY AIR WILL QUICKLY MOISTEN THROUGH THE MORNING HOURS WITH
FAVORABLE SFC-700MB MOISTURE PROFILE. LOOKING UPSTAIRS AT
250MB...THERE IS SOME WEAK SPEED DIFFLUENCE IN CYCLONIC FLOW SOUTH
OF THE LOW AND TROUGH AXIS. NOT MUCH TO HANG YOUR HAT ON AT THE
SURFACE EXCEPT FOR WEAK SPEED AND DIRECTIONAL CONVERGENCE SO THE
SEABREEZE WILL BECOME ACTIVE LATER THIS MORNING WITH CONVECTION
SPREADING WESTWARD WITH TIME. HRRR SHOWS INITIATION IN THE COASTAL
SECTIONS AROUND 16Z THEN SPREADING WESTWARD AND I FOLLOWED THIS
TREND. EXPECT SCATTERED COVERAGE OF CONVECTION WITH BRIEF HEAVY
RAINFALL AND GUSTY WINDS CORRESPONDING TO INVERTED-V FORECAST
SOUNDINGS ACROSS MUCH OF THE AREA.
CONVECTION WILL WANE IN THE EVENING HOURS REACHING THE FAR WESTERN
SECTIONS. HIGHER PWAT AND MOISTURE WILL BE ADVECTED ACROSS THE AREA
TONIGHT INTO TUESDAY. DEEPER MOISTURE ARRIVES AS THE LARGE SCALE
LIFT MOVES EAST OF THE AREA AND THE TROUGH AXIS IS DIRECTLY
OVERHEAD. THEREFORE...LARGE SCALE LIFT IS NEUTRAL. CONVECTION WILL
GET GOING OVERNIGHT ONCE AGAIN ACROSS THE GULF WATERS THEN SPREAD
INLAND AND DEVELOP ON THE SEABREEZE ONCE AGAIN. A LITTLE COOLER MID
LEVEL TEMPERATURES WILL LEAD TO SLIGHTLY BETTER CAPES AND
INSTABILITY. GUSTY WINDS AND HEAVY DOWNPOURS WILL BE OF CONCERN ONCE
AGAIN TUESDAY.
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...500MB TROUGH AXIS TO
LINGER ALONG THE TEXAS COAST EXTENDING INTO THE RGV WEDNESDAY
THEN SHIFT EASTWARD THURSDAY BEFORE SOME OF THE ENERGY SPLITS AND
THE SOUTHERN END OF THE TROUGH TAKES ON A RETROGRADING TRACK AS AN
INVERTED TROUGH FRIDAY INTO SATURDAY. GFS ENSEMBLE MEAN AND
DETERMINISTIC MODELS ARE MORE DISTINCT WITH THE SOUTHERN ENERGY
/INVERTED TROUGH/ WITH WITH THE ECMWF NOT AS TRANSPARENT
INDICATING MORE ENERGY REMAINING WITH THE TROUGH RESIDING OVER THE
SE U.S. MOISTURE FIELDS AND POPS GUIDANCE TREND DOWN WEDNESDAY AND
THURSDAY FROM THE HIGH POPS OF MONDAY AND TUESDAY. GFS/MAV TRENDS
UP FRIDAY AS THE INVERTED TROUGH APPROACHES. ECMWF CONTINUES TO
HAVE A HIGH POP BIAS BUT SHOWS A DOWNWARD TREND THROUGH THE WEEK.
THE FORECAST IS LEANING MORE WITH GFS AND ITS STRONGER SOUTHERN
INVERTED TROUGH FEATURE WITH BOTH THE EMSEMBLE AND DETERMINISTIC
SOLUTIONS IN BETTER AGREEMENT THEN THE DIVERGING OR WEAKER ECMWF.
FORECAST TAKES ON A GENERAL MIDDLE OF THE ROAD TREND WITH
ISOLATED TO SCATTERED CONVECTION WITH WEDNESDAY AND FRIDAY AND
POSSIBLY NEXT SATURDAY SEEING THE HIGHEST CHANCES BETTER OVERALL
AREAL COVERAGE. DIFFICULT TO PINPOINT IF THE EAST WILL SEE MORE
PRECIPITATION THAN THE WEST ON ANY PARTICULAR DAY AS WE MOVE INTO
OUR RAINIEST MONTH. MODELS SUGGEST AN AVERAGE MOISTURE CONTENT
THROUGH THE ATMOSPHERIC COLUMN WITH PWATS AROUND 1.75 INCH RANGE.
DO NOT SEE ANY DEEP TROPICAL MOISTURE THAT WOULD RAISE THE CONCERN
OF HEAVY RAIN AT THIS TIME BUT ISOLATED DOWNPOURS ARE NOT OUT OF
QUESTION WITH ANY STORMS THAT DO DEVELOP. TEMPERATURES TO AVERAGE
NEAR SEASONAL NORMALS WITH NO EXTREMES INDICATED.
MARINE...NOW THROUGH TUESDAY...WEAK HIGH PRESSURE WILL SUPPORT
LIGHT TO MODERATE SOUTHEAST WINDS AND LOW SEAS. SHOWERS AND
THUNDERSTORMS WILL INCREASE TODAY THROUGH TUESDAY DUE TO
INSTABILITY ALOFT AND INCREASED MOISTURE MOVING UP FROM SOUTH OF
THE AREA.
TUESDAY NIGHT THROUGH FRIDAY...BROAD HIGH PRESSURE TO REMAIN OVER
THE GULF WITH A WEAK UPPER LEVEL TROUGH OVER THE NORTHWEST AND
NORTH CENTRAL GULF. LIGHT ONSHORE WINDS AND SLIGHT SEAS TO PERSIST
INTO THURSDAY. A MID LEVEL INVERTED TROUGH TO TRACK THROUGH THE
LOWER TEXAS COASTAL WATERS FRIDAY INTO SATURDAY WIND A SLIGHT
INCREASE OF ONSHORE WINDS AND SLIGHT UPTICK OF SEAS. DAILY SHOWERS
AND THUNDERSTORMS ARE EXPECTED WITH BEST CHANCES WEDNESDAY AND
FRIDAY.
BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
64
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
358 AM CDT MON AUG 31 2015
.SHORT TERM /TODAY THROUGH TUESDAY/...FORECAST CHALLENGE FOR THE SHORT
TERM WILL BE PRECIPITATION CHANCES AND PLACEMENT.
EARLY MORNING WATER VAPOR IMAGERY DEPICTS A MID LEVEL LOW PRESSURE
AREA SPINNING NICELY ACROSS SOUTH CENTRAL TEXAS WITH A FINGER OF DRY
AIR ADVECTING INTO TO THE WESTERN CWA ON THE SOUTHSIDE OF THIS
FEATURE. TIME HEIGHTS SHOW THIS DRY AIR NICELY IN THE 600-400MB
LAYER. THIS LOW PRESSURE AREA IS LOCATED WITHIN A BROAD TROUGH
EXTENDING FROM NORTHEAST MEXICO NORTHEASTWARD THROUGH EASTERN
ARKANSAS. PWAT ON THE 00Z BRO SOUNDING WAS 1.93 INCHES WITH EVEN
HIGHER PWATS SOUTHWARD INTO THE BAY OF CAMPECHE ACCORDING TO BLENDED
TPW PRODUCTS. AT THIS HOUR CONVECTION IN THE GULF IS INCREASING
AHEAD OF DEEPER MOISTURE AND LARGE SCALE LIFT.
TROUGH AXIS WILL MOVE SLOWLY EASTWARD TODAY FROM ITS PRESENT
LOCATION LEAVING THE AREA IN FAVORABLE LARGE SCALE LIFT. MID LEVEL
DRY AIR WILL QUICKLY MOISTEN THROUGH THE MORNING HOURS WITH
FAVORABLE SFC-700MB MOISTURE PROFILE. LOOKING UPSTAIRS AT
250MB...THERE IS SOME WEAK SPEED DIFFLUENCE IN CYCLONIC FLOW SOUTH
OF THE LOW AND TROUGH AXIS. NOT MUCH TO HANG YOUR HAT ON AT THE
SURFACE EXCEPT FOR WEAK SPEED AND DIRECTIONAL CONVERGENCE SO THE
SEABREEZE WILL BECOME ACTIVE LATER THIS MORNING WITH CONVECTION
SPREADING WESTWARD WITH TIME. HRRR SHOWS INITIATION IN THE COASTAL
SECTIONS AROUND 16Z THEN SPREADING WESTWARD AND I FOLLOWED THIS
TREND. EXPECT SCATTERED COVERAGE OF CONVECTION WITH BRIEF HEAVY
RAINFALL AND GUSTY WINDS CORRESPONDING TO INVERTED-V FORECAST
SOUNDINGS ACROSS MUCH OF THE AREA.
CONVECTION WILL WANE IN THE EVENING HOURS REACHING THE FAR WESTERN
SECTIONS. HIGHER PWAT AND MOISTURE WILL BE ADVECTED ACROSS THE AREA
TONIGHT INTO TUESDAY. DEEPER MOISTURE ARRIVES AS THE LARGE SCALE
LIFT MOVES EAST OF THE AREA AND THE TROUGH AXIS IS DIRECTLY
OVERHEAD. THEREFORE...LARGE SCALE LIFT IS NEUTRAL. CONVECTION WILL
GET GOING OVERNIGHT ONCE AGAIN ACROSS THE GULF WATERS THEN SPREAD
INLAND AND DEVELOP ON THE SEABREEZE ONCE AGAIN. A LITTLE COOLER MID
LEVEL TEMPERATURES WILL LEAD TO SLIGHTLY BETTER CAPES AND
INSTABILITY. GUSTY WINDS AND HEAVY DOWNPOURS WILL BE OF CONCERN ONCE
AGAIN TUESDAY.
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...500MB TROUGH AXIS TO
LINGER ALONG THE TEXAS COAST EXTENDING INTO THE RGV WEDNESDAY
THEN SHIFT EASTWARD THURSDAY BEFORE SOME OF THE ENERGY SPLITS AND
THE SOUTHERN END OF THE TROUGH TAKES ON A RETROGRADING TRACK AS AN
INVERTED TROUGH FRIDAY INTO SATURDAY. GFS ENSEMBLE MEAN AND
DETERMINISTIC MODELS ARE MORE DISTINCT WITH THE SOUTHERN ENERGY
/INVERTED TROUGH/ WITH WITH THE ECMWF NOT AS TRANSPARENT
INDICATING MORE ENERGY REMAINING WITH THE TROUGH RESIDING OVER THE
SE U.S. MOISTURE FIELDS AND POPS GUIDANCE TREND DOWN WEDNESDAY AND
THURSDAY FROM THE HIGH POPS OF MONDAY AND TUESDAY. GFS/MAV TRENDS
UP FRIDAY AS THE INVERTED TROUGH APPROACHES. ECMWF CONTINUES TO
HAVE A HIGH POP BIAS BUT SHOWS A DOWNWARD TREND THROUGH THE WEEK.
THE FORECAST IS LEANING MORE WITH GFS AND ITS STRONGER SOUTHERN
INVERTED TROUGH FEATURE WITH BOTH THE EMSEMBLE AND DETERMINISTIC
SOLUTIONS IN BETTER AGREEMENT THEN THE DIVERGING OR WEAKER ECMWF.
FORECAST TAKES ON A GENERAL MIDDLE OF THE ROAD TREND WITH
ISOLATED TO SCATTERED CONVECTION WITH WEDNESDAY AND FRIDAY AND
POSSIBLY NEXT SATURDAY SEEING THE HIGHEST CHANCES BETTER OVERALL
AREAL COVERAGE. DIFFICULT TO PINPOINT IF THE EAST WILL SEE MORE
PRECIPITATION THAN THE WEST ON ANY PARTICULAR DAY AS WE MOVE INTO
OUR RAINIEST MONTH. MODELS SUGGEST AN AVERAGE MOISTURE CONTENT
THROUGH THE ATMOSPHERIC COLUMN WITH PWATS AROUND 1.75 INCH RANGE.
DO NOT SEE ANY DEEP TROPICAL MOISTURE THAT WOULD RAISE THE CONCERN
OF HEAVY RAIN AT THIS TIME BUT ISOLATED DOWNPOURS ARE NOT OUT OF
QUESTION WITH ANY STORMS THAT DO DEVELOP. TEMPERATURES TO AVERAGE
NEAR SEASONAL NORMALS WITH NO EXTREMES INDICATED.
&&
.MARINE...NOW THROUGH TUESDAY...WEAK HIGH PRESSURE WILL SUPPORT
LIGHT TO MODERATE SOUTHEAST WINDS AND LOW SEAS. SHOWERS AND
THUNDERSTORMS WILL INCREASE TODAY THROUGH TUESDAY DUE TO
INSTABILITY ALOFT AND INCREASED MOISTURE MOVING UP FROM SOUTH OF
THE AREA.
TUESDAY NIGHT THROUGH FRIDAY...BROAD HIGH PRESSURE TO REMAIN OVER
THE GULF WITH A WEAK UPPER LEVEL TROUGH OVER THE NORTHWEST AND
NORTH CENTRAL GULF. LIGHT ONSHORE WINDS AND SLIGHT SEAS TO PERSIST
INTO THURSDAY. A MID LEVEL INVERTED TROUGH TO TRACK THROUGH THE
LOWER TEXAS COASTAL WATERS FRIDAY INTO SATURDAY WIND A SLIGHT
INCREASE OF ONSHORE WINDS AND SLIGHT UPTICK OF SEAS. DAILY SHOWERS
AND THUNDERSTORMS ARE EXPECTED WITH BEST CHANCES WEDNESDAY AND
FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 90 78 90 77 / 30 40 50 20
BROWNSVILLE 92 76 91 76 / 40 40 50 20
HARLINGEN 93 75 93 75 / 40 30 50 20
MCALLEN 96 78 96 78 / 40 20 40 20
RIO GRANDE CITY 97 76 98 75 / 30 20 30 20
SOUTH PADRE ISLAND 85 79 86 80 / 30 40 50 20
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
55...SHORT TERM
59...LONG TERM
65...GRAPHICS
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1225 PM CDT MON AUG 31 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT MON AUG 31 2015
EARLY THIS MORNING...LOW STRATUS HAS QUICKLY DEVELOPED ACROSS
NORTH-CENTRAL IA AND ALONG THE MN/IA BORDER AS WELL AS ACROSS
NORTHERN WI. 31.07Z RAP SHOWS THIS STRATUS FILLING-IN ACROSS MUCH
OF THE FORECAST AREA BY SUNRISE. THESE CLOUDS...COMBINED WITH
BRISK WEST-SOUTHWEST WIND JUST OFF THE SURFACE SHOULD PRECLUDE
WIDESPREAD DENSE FOG...BUT CAN STILL EXPECT SOME AREAS OF REDUCED
VISIBILITY...ESPECIALLY FOR THOSE AREAS THAT REMAIN MOSTLY CLEAR
FOR A LONGER PERIOD.
AS QUICKLY AS THE STRATUS DEVELOPS...MOST HIGH RESOLUTION MODELS
DISSIPATE IT JUST AS QUICKLY BY LATE MORNING AS 15 TO 20 KTS MIX
WITHIN DEEPENING BOUNDARY LAYER. EXPECT A RETURN TO AT LEAST
PARTLY SUNNY SKIES BY EARLY AFTERNOON. PRIMARY IMPACT OF CLOUDS
WILL BE TO SLOW TEMPERATURE RISE THROUGH THE DAY...SO DROPPED
AFTERNOON HIGHS A FEW DEGREES INTO THE LOWER TO MID 80S.
TONIGHT NOT LIKELY TO BE COMPLETELY CLOUD FREE AND WITH 10 TO 20
KTS ATOP NOCTURNAL INVERSION...FOG THREAT SHOULD BE LOWER THAN THE
PAST COUPLE NIGHTS. TEMPERATURES WILL DROP INTO THE MID TO UPPER
60S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 340 AM CDT MON AUG 31 2015
MAIN STORY FOR THE WEEK CONTINUES TO BE WELL ABOVE NORMAL
TEMPERATURES WITH A BROAD 500 HPA RIDGE PARKED ACROSS THE EASTERN
CONUS. WITH 925 HPA TEMPERATURES GENERALLY WOBBLING BETWEEN 24 AND
26 CELSIUS...DAILY HIGHS HIGHS WILL TOP OUT IN THE MID TO UPPER
80S WITH SOME 90 PLUS DEGREE READINGS ALONG AND EAST OF THE MS
RIVER.
WILL KEEP 20-30 PERCENT MODEL CONSENSUS POPS WEDNESDAY NIGHT
THROUGH FRIDAY...BUT THINK MAJORITY OF THE WEEK WILL REMAIN DRY.
MULTIPLE WEAK/ILL-RESOLVED SHORT-WAVES MOVE ACROSS THE REGION IN
SOUTHWEST FLOW ALOFT THAT COULD PROVIDE A FOCUSING MECHANISM FOR
CONVECTION. HOWEVER...AXIS OF MAXIMUM MID-LEVEL MOISTURE TRANSPORT
REMAINS WEST OF THE FORECAST AREA...CLOSER TO THE WESTERN CONUS
TROUGH. DAILY INSTABILITY IS PRESENT WITH ABOVE NORMAL TEMPERATURES/
SURFACE DEWPOINTS IN THE 60S...BUT LARGE SCALE RIDGE SQUASHES ANY
DEEP LAYER SHEAR OF SIGNIFICANCE. FOR NOW...DIFFICULT TO PROVIDE
DETAILS ON TIMING OR COVERAGE IF ANYTHING DOES DEVELOP SO BROAD-
BRUSHED POPS SEEM REASONABLE.
BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN SATURDAY NIGHT
INTO SUNDAY AS 31.00Z GFS/ECMWF ATTEMPT TO BREAK DOWN EASTERN
CONUS RIDGE BY MOVING A BROAD PACIFIC TROUGH INTO THE ROCKIES/
NORTHERN PLAINS. GFS IS MUCH QUICKER IN DOING SO COMPARED TO THE
SLOWER ECMWF...SO DEFINITE TIMING ISSUES EMERGE. FOR NOW...A
BLENDED APPROACH IS PRUDENT RESULTING IN CHANCE POPS SATURDAY
NIGHT THROUGH THE DAY ON SUNDAY. SHOULD SEE TEMPERATURES FALL BACK
TO MORE SEASONABLE LEVELS ONCE TROUGH PASSES...BUT WHETHER THIS
OCCURS BY SUNDAY OR EARLY NEXT WEEK IS YET TO BE SEEN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1225 PM CDT MON AUG 31 2015
INCREASING SOUTH-SOUTHWEST LOWER LEVEL FLOW WAS ALLOWING FOR MORE
MIXING TODAY...WITH THE MVFR/IFR STRATO-CU DECK ERODING/LIFTING
NORTH OF THE TAF SITES BY 17Z TODAY. MORE DIURNAL WARMING/DEEPER
MIXING THIS AFTERNOON SHOULD RAISE SCT CUMULUS HGTS INTO THE 2500 FT
RANGE FOR THE AFTERNOON. SOUNDINGS/X-SECTIONS THEN SHOW DRYING BELOW
900MB IN THE SOUTHWEST FLOW FOR TONIGHT INTO TUE...WITH A MOISTURE
INCREASE TONIGHT AROUND 850MB OR ABOUT 4000 FT AGL. CARRIED THIS AS
A SCT035/SCT040 DECK AT KRST/KLSE RESPECTIVELY FOR TONIGHT-TUE
MORNING. WITH A MOIST BOUNDARY LAYER AIRMASS AND NOCTURNAL
COOLING...CONTINUED A MENTION OF SOME MVFR BR DURING THE LATE NIGHT
AND EARLY MORNING HOURS...MAINLY 08Z-14Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ROGERS
LONG TERM....ROGERS
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
635 AM CDT MON AUG 31 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT MON AUG 31 2015
EARLY THIS MORNING...LOW STRATUS HAS QUICKLY DEVELOPED ACROSS
NORTH-CENTRAL IA AND ALONG THE MN/IA BORDER AS WELL AS ACROSS
NORTHERN WI. 31.07Z RAP SHOWS THIS STRATUS FILLING-IN ACROSS MUCH
OF THE FORECAST AREA BY SUNRISE. THESE CLOUDS...COMBINED WITH
BRISK WEST-SOUTHWEST WIND JUST OFF THE SURFACE SHOULD PRECLUDE
WIDESPREAD DENSE FOG...BUT CAN STILL EXPECT SOME AREAS OF REDUCED
VISIBILITY...ESPECIALLY FOR THOSE AREAS THAT REMAIN MOSTLY CLEAR
FOR A LONGER PERIOD.
AS QUICKLY AS THE STRATUS DEVELOPS...MOST HIGH RESOLUTION MODELS
DISSIPATE IT JUST AS QUICKLY BY LATE MORNING AS 15 TO 20 KTS MIX
WITHIN DEEPENING BOUNDARY LAYER. EXPECT A RETURN TO AT LEAST
PARTLY SUNNY SKIES BY EARLY AFTERNOON. PRIMARY IMPACT OF CLOUDS
WILL BE TO SLOW TEMPERATURE RISE THROUGH THE DAY...SO DROPPED
AFTERNOON HIGHS A FEW DEGREES INTO THE LOWER TO MID 80S.
TONIGHT NOT LIKELY TO BE COMPLETELY CLOUD FREE AND WITH 10 TO 20
KTS ATOP NOCTURNAL INVERSION...FOG THREAT SHOULD BE LOWER THAN THE
PAST COUPLE NIGHTS. TEMPERATURES WILL DROP INTO THE MID TO UPPER
60S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 340 AM CDT MON AUG 31 2015
MAIN STORY FOR THE WEEK CONTINUES TO BE WELL ABOVE NORMAL
TEMPERATURES WITH A BROAD 500 HPA RIDGE PARKED ACROSS THE EASTERN
CONUS. WITH 925 HPA TEMPERATURES GENERALLY WOBBLING BETWEEN 24 AND
26 CELSIUS...DAILY HIGHS HIGHS WILL TOP OUT IN THE MID TO UPPER
80S WITH SOME 90 PLUS DEGREE READINGS ALONG AND EAST OF THE MS
RIVER.
WILL KEEP 20-30 PERCENT MODEL CONSENSUS POPS WEDNESDAY NIGHT
THROUGH FRIDAY...BUT THINK MAJORITY OF THE WEEK WILL REMAIN DRY.
MULTIPLE WEAK/ILL-RESOLVED SHORT-WAVES MOVE ACROSS THE REGION IN
SOUTHWEST FLOW ALOFT THAT COULD PROVIDE A FOCUSING MECHANISM FOR
CONVECTION. HOWEVER...AXIS OF MAXIMUM MID-LEVEL MOISTURE TRANSPORT
REMAINS WEST OF THE FORECAST AREA...CLOSER TO THE WESTERN CONUS
TROUGH. DAILY INSTABILITY IS PRESENT WITH ABOVE NORMAL TEMPERATURES/
SURFACE DEWPOINTS IN THE 60S...BUT LARGE SCALE RIDGE SQUASHES ANY
DEEP LAYER SHEAR OF SIGNIFICANCE. FOR NOW...DIFFICULT TO PROVIDE
DETAILS ON TIMING OR COVERAGE IF ANYTHING DOES DEVELOP SO BROAD-
BRUSHED POPS SEEM REASONABLE.
BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN SATURDAY NIGHT
INTO SUNDAY AS 31.00Z GFS/ECMWF ATTEMPT TO BREAK DOWN EASTERN
CONUS RIDGE BY MOVING A BROAD PACIFIC TROUGH INTO THE ROCKIES/
NORTHERN PLAINS. GFS IS MUCH QUICKER IN DOING SO COMPARED TO THE
SLOWER ECMWF...SO DEFINITE TIMING ISSUES EMERGE. FOR NOW...A
BLENDED APPROACH IS PRUDENT RESULTING IN CHANCE POPS SATURDAY
NIGHT THROUGH THE DAY ON SUNDAY. SHOULD SEE TEMPERATURES FALL BACK
TO MORE SEASONABLE LEVELS ONCE TROUGH PASSES...BUT WHETHER THIS
OCCURS BY SUNDAY OR EARLY NEXT WEEK IS YET TO BE SEEN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 635 AM CDT MON AUG 31 2015
LIGHT SOUTHERLY FLOW IS BRINGING A MORE HUMID AIR MASS INTO THE
REGION THIS MORNING. THIS WAS PRODUCING EXPANSIVE AREA OF LIFR TO
MVFR STRATUS FROM IOWA INTO SOUTHEAST MN/WESTERN AND NORTHERN WI.
THERE WAS ALSO POCKETS OF VSBY BLO 1SM IN BR. EXPECTING
STRATUS/FOG TO LIFT AND SCATTER OUT LATER THIS MORNING AS
STRONGER SOUTH/SOUTHWEST WINDS MIX OUT THE BOUNDARY LAYER. VFR
CONDITIONS THEN EXPECTED AFTER 16Z. SOUTHERLY AIRFLOW WILL LIKELY
PRODUCE MORE STRATUS TONIGHT ACROSS THE AREA...BUT EXTENT IS NOT
CERTAIN AT THIS TIME. LOOKS LIKE IF CEILINGS DID FORM AT KRST/KLSE
IT WOULD LIKELY BE IN MVFR CATEGORY. SHOULD ALSO SEE SOME LIGHT
FOG WITH VSBY IN THE 5-6SM RANGE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ROGERS
LONG TERM...ROGERS
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
340 AM CDT MON AUG 31 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT MON AUG 31 2015
EARLY THIS MORNING...LOW STRATUS HAS QUICKLY DEVELOPED ACROSS
NORTH-CENTRAL IA AND ALONG THE MN/IA BORDER AS WELL AS ACROSS
NORTHERN WI. 31.07Z RAP SHOWS THIS STRATUS FILLING-IN ACROSS MUCH
OF THE FORECAST AREA BY SUNRISE. THESE CLOUDS...COMBINED WITH
BRISK WEST-SOUTHWEST WIND JUST OFF THE SURFACE SHOULD PRECLUDE
WIDESPREAD DENSE FOG...BUT CAN STILL EXPECT SOME AREAS OF REDUCED
VISIBILITY...ESPECIALLY FOR THOSE AREAS THAT REMAIN MOSTLY CLEAR
FOR A LONGER PERIOD.
AS QUICKLY AS THE STRATUS DEVELOPS...MOST HIGH RESOLUTION MODELS
DISSIPATE IT JUST AS QUICKLY BY LATE MORNING AS 15 TO 20 KTS MIX
WITHIN DEEPENING BOUNDARY LAYER. EXPECT A RETURN TO AT LEAST
PARTLY SUNNY SKIES BY EARLY AFTERNOON. PRIMARY IMPACT OF CLOUDS
WILL BE TO SLOW TEMPERATURE RISE THROUGH THE DAY...SO DROPPED
AFTERNOON HIGHS A FEW DEGREES INTO THE LOWER TO MID 80S.
TONIGHT NOT LIKELY TO BE COMPLETELY CLOUD FREE AND WITH 10 TO 20
KTS ATOP NOCTURNAL INVERSION...FOG THREAT SHOULD BE LOWER THAN THE
PAST COUPLE NIGHTS. TEMPERATURES WILL DROP INTO THE MID TO UPPER
60S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 340 AM CDT MON AUG 31 2015
MAIN STORY FOR THE WEEK CONTINUES TO BE WELL ABOVE NORMAL
TEMPERATURES WITH A BROAD 500 HPA RIDGE PARKED ACROSS THE EASTERN
CONUS. WITH 925 HPA TEMPERATURES GENERALLY WOBBLING BETWEEN 24 AND
26 CELSIUS...DAILY HIGHS HIGHS WILL TOP OUT IN THE MID TO UPPER
80S WITH SOME 90 PLUS DEGREE READINGS ALONG AND EAST OF THE MS
RIVER.
WILL KEEP 20-30 PERCENT MODEL CONSENSUS POPS WEDNESDAY NIGHT
THROUGH FRIDAY...BUT THINK MAJORITY OF THE WEEK WILL REMAIN DRY.
MULTIPLE WEAK/ILL-RESOLVED SHORT-WAVES MOVE ACROSS THE REGION IN
SOUTHWEST FLOW ALOFT THAT COULD PROVIDE A FOCUSING MECHANISM FOR
CONVECTION. HOWEVER...AXIS OF MAXIMUM MID-LEVEL MOISTURE TRANSPORT
REMAINS WEST OF THE FORECAST AREA...CLOSER TO THE WESTERN CONUS
TROUGH. DAILY INSTABILITY IS PRESENT WITH ABOVE NORMAL TEMPERATURES/
SURFACE DEWPOINTS IN THE 60S...BUT LARGE SCALE RIDGE SQUASHES ANY
DEEP LAYER SHEAR OF SIGNIFICANCE. FOR NOW...DIFFICULT TO PROVIDE
DETAILS ON TIMING OR COVERAGE IF ANYTHING DOES DEVELOP SO BROAD-
BRUSHED POPS SEEM REASONABLE.
BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN SATURDAY NIGHT
INTO SUNDAY AS 31.00Z GFS/ECMWF ATTEMPT TO BREAK DOWN EASTERN
CONUS RIDGE BY MOVING A BROAD PACIFIC TROUGH INTO THE ROCKIES/
NORTHERN PLAINS. GFS IS MUCH QUICKER IN DOING SO COMPARED TO THE
SLOWER ECMWF...SO DEFINITE TIMING ISSUES EMERGE. FOR NOW...A
BLENDED APPROACH IS PRUDENT RESULTING IN CHANCE POPS SATURDAY
NIGHT THROUGH THE DAY ON SUNDAY. SHOULD SEE TEMPERATURES FALL BACK
TO MORE SEASONABLE LEVELS ONCE TROUGH PASSES...BUT WHETHER THIS
OCCURS BY SUNDAY OR EARLY NEXT WEEK IS YET TO BE SEEN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1125 PM CDT SUN AUG 30 2015
LIGHT SFC WINDS...HIGH PRESSURE IN THE VICINITY...AND T/TD SPREAD
AROUND 2 F AT LATE EVENING ALL SUPPORT DENSE FOG IN THE RIVER VALLEY
AT KLSE. HOWEVER...THE DEPTH OF THE LIGHT WIND LAYER DOES NOT.
BUFKIT HRRR/RAP/NAM SOUNDINGS ALL POINT TO 10+ KTS OF WIND WITHIN A
COUPLE HUNDRED FEET OF THE SURFACE. THIS STIRRING GENERALLY
PRECLUDES DENSE FOG FORMATION IN THE VALLEY - OR AT LEAST ITS
ABILITY TO SPREAD. IN ADDITION...IT CAN WORK AGAINST A LOW STRATUS
LAYER DEVELOPING. HOWEVER...WITH WIDESPREAD LOW LEVEL SATURATION
ACROSS THE REGION...MVFR BR IS CERTAINLY POSSIBLE...AT KLSE AND
KRST.
AS FOR CIGS...HRRR/RAP INCREASE THE LOW SATURATION ACROSS THE
SOUTH...WHICH COULD MANIFEST AS LOW STRATUS AND/OR THICK FOG. LATEST
RUNS KEEP THIS STRATUS/FOG THREAT SOUTH OF THE TAF SITES...AND WILL
HAVE THE FORECAST FOLLOW SUIT.
IT WILL BE ANOTHER EARLY MORNING OF CLOSELY FOLLOWING
OBS/TRENDS...WITH UPDATES MADE IF NEEDED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ROGERS
LONG TERM...ROGERS
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS TUCSON AZ
950 PM MST TUE SEP 1 2015
.SYNOPSIS...AMPLE MOISTURE IN COMBINATION WITH SEVERAL DISTURBANCES
WILL MAINTAIN SCATTERED THUNDERSTORMS THROUGH SATURDAY. ISOLATED TO
SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL THEN
PREVAIL EARLY NEXT WEEK. EXPECT BELOW AVERAGE DAYTIME TEMPERATURES
THROUGH SATURDAY FOLLOWED BY A MODEST WARMING TREND EARLY NEXT WEEK.
&&
.DISCUSSION...KEMX WSR-88D DETECTED ISOLATED 35-55 DBZ ECHOES FROM
NEAR THE TUCSON MOUNTAINS NWWD INTO SOUTH CENTRAL PINAL COUNTY. THE
REST OF SE ARIZONA WAS VOID OF PRECIP ECHOES. THESE SHOWERS AND
THUNDERSTORMS ONGOING WEST-TO-NORTHWEST OF THE TUCSON METRO AREA
WERE AHEAD OF A REMNANT MCV/CYCLONIC CIRCULATION FEATURE APPROACHING
THE INTERNATIONAL BORDER ADJACENT SANTA CRUZ COUNTY.
BASED ON THE 02/00Z NAM12 AND SEVERAL HRRR SOLUTIONS AS WELL AS
RADAR TRENDS...HAVE MAINTAINED ISOLATED SHOWERS/TSTMS ACROSS MUCH OF
THIS FORECAST AREA THE REST OF TONIGHT INTO EARLY WED MORNING.
ADEQUATE MOISTURE IN COMBINATION WITH A MODESTLY UNSTABLE
ENVIRONMENT AND THE AFOREMENTIONED CYCLONIC CIRCULATION FEATURE
SHOULD BE SUFFICIENT TO SUPPORT AT LEAST A SLIGHT CHANCE OF
SHOWERS/TSTMS THRU DAYBREAK WED. GIVEN THE PAUCITY OF SIGNIFICANT
RAINFALL EARLIER THIS EVENING...BELIEVE THAT AMOUNTS THE REST OF
TONIGHT WILL BE CONSIDERABLY LESS THAN 24 HOURS AGO.
OTHERWISE...EXPECT MOSTLY CLOUDY SKIES ACROSS MUCH OF SE ARIZONA THE
REST OF TONIGHT. A FAIRLY ACTIVE PERIOD FOR SHOWERS/TSTMS MAY VERY
WELL BE ON TAP WED AFTERNOON/EVENING IF THE 01/12Z UNIV OF AZ WRF
NAM/GFS SOLUTIONS AND THE 02/00Z NAM12 IS REALITY. HIGH TEMPS WED
WILL AVERAGE ABOUT 2-4 DEGS F OR SO BELOW NORMAL. EVEN COOLER
DAYTIME TEMPS ARE FORECAST TO OCCUR THUR.
PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.
&&
.AVIATION...VALID THRU 03/06Z.
ISOLATED TO SCATTERED -TSRA/-SHRA INTO WEDNESDAY MORNING...THEN
SCATTERED TO PERHAPS NUMEROUS -TSRA/-SHRA ACROSS MUCH OF SE ARIZONA
WEDNESDAY AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS AND WIND
GUSTS OF 35 TO 45 KTS WILL OCCUR WITH THE STRONGER THUNDERSTORMS.
OTHERWISE...EXPECT LAYERED CLOUDS MOSTLY BETWEEN 10-15K FT AGL AND
SURFACE WIND GENERALLY LESS THAN 10 KTS INTO WEDNESDAY EVENING.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS ACROSS
MUCH OF SOUTHEAST ARIZONA THROUGH SATURDAY. LOCALLY HEAVY RAINFALL
AND BRIEF GUSTY WINDS WILL ACCOMPANY THE STRONGER THUNDERSTORMS.
THEREAFTER...ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS WILL PREVAIL SUNDAY THROUGH TUESDAY. THE BEST CHANCE
OF THIS ACTIVITY WILL BE ACROSS GREENLEE...GRAHAM AND COCHISE
COUNTIES EAST OF TUCSON. DAYTIME TEMPERATURES WILL BE BELOW SEASONAL
AVERAGES DURING THE NEXT SEVERAL DAYS FOLLOWED BY A MODEST WARMING
TREND EARLY NEXT WEEK.
&&
.PREV DISCUSSION /232 PM MST/...A DISTURBANCE EMBEDDED IN THE
SOUTHWESTERLY FLOW ALOFT WILL HELP ENHANCE THUNDERSTORM ACTIVITY
WEDNESDAY INTO THURSDAY. MODELS CONTINUED TO SUGGEST THAT A SYSTEM
APPROACHING THE SOUTHERN TIP OF BAJA WILL HELP PUSH DEEPER MOISTURE
BACK INTO THE AREA BY THE WEEKEND. THIS DEEPER MOISTURE WILL
MAINTAIN RAIN CHANCES THIS WEEK. OTHERWISE...EXPECT COOLER HIGH
TEMPERATURES THAN LAST WEEK WITH READINGS REMAINING BELOW NORMAL THE
NEXT FEW DAYS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS MIAMI FL
200 AM EDT WED SEP 2 2015
.AVIATION...
WEAK HIGH PRESSURE WILL RESULT IN A TYPICAL SUMMER DAY ACROSS
SOUTH FLORIDA WITH L/V EARLY MORNING WIND AND SEA BREEZES
DEVELOPING ALONG BOTH COASTS. STEERING FLOW WILL BE SOUTHEAST TO
NORTHWEST SO AS DIURNAL CONVECTION DEVELOPS ALONG THE SEA BREEZE
BOUNDARIES, THE CELLS WILL MOVE INLAND AND AWAY FROM THE
TERMINALS. THIS ACTIVITY SHOULD BE FAR ENOUGH AWAY TO NOT INCLUDE
IN THE FORECAST AT THIS TIME.
KOB
&&
.PREV DISCUSSION... /ISSUED 800 PM EDT TUE SEP 1 2015/
UPDATE...
SHOWERS AND THUNDERSTORMS CONTINUE TO DECREASE IN COVERAGE ACROSS
THE AREA EARLY THIS EVENING WITH HEATING LOSS. LATEST HRRR KEEPS
ONLY ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ACROSS MAINLY
THE ATLANTIC AND GULF WATERS THROUGH THE OVERNIGHT HOURS. UPDATED
FORECAST TO ADJUST FOR THESE TRENDS.
PREV DISCUSSION... /ISSUED 743 PM EDT TUE SEP 1 2015/
AVIATION...
VFR OVERNIGHT. OUTFLOW BOUNDARY WHICH MOVED DUE EAST LATE THIS
AFTERNOON GENERATED A FEW WIND GUSTS AND SOME BRIEF MVFR CIGS
WHICH WILL DISSIPATE THIS EVENING. REGIME IS SIMILAR TOMORROW,
WITH SEABREEZES ON BOTH COASTS AND STORMS FOCUSED OVER THE
INTERIOR. EAST COAST TERMINALS, POSSIBLY WITH THE EXCEPTION OF TMB
AND PBI, MAY STAY DRY AGAIN. WITH THE GULF BREEZE FADING, STORMS
JUST EAST OF APF MAY CROSS THAT TERMINAL IN THE NEAR TERM TONIGHT.
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
228 AM EDT WED SEP 2 2015
.SYNOPSIS...
AN UPPER LEVEL RIDGE CENTERED TO OUR SOUTH WILL SHIFT SLOWLY WEST
TOWARDS FLORIDA AND THE EASTERN GULF OF MEXICO...WHILE AN UPPER
LEVEL TROUGH DEVELOPS OVER THE EAST COAST...THROUGH FRIDAY. A
RELATIVELY DRY ATMOSPHERE WILL REMAIN IN PLACE OVER OUR FORECAST
AREA TODAY...ENSURING FAIR WEATHER WITH A TREND TOWARDS WARMER MAX
TEMPS. A SLIGHT INCREASE IN MOISTURE AND SOME UPPER ENERGY
EXPECTED TO LEAD TO A SLIGHT CHANCE OF MAINLY AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS THURSDAY AND FRIDAY. INDICATIONS
OF A BACK DOOR FRONT AND INCREASING MOISTURE MAY SPELL INCREASING
CHANCES FOR PRECIPITATION THIS WEEKEND INTO EARLY NEXT
WEEK...ALONG WITH A TREND TOWARDS COOLER TEMPS.
&&
.NEAR TERM /THROUGH TONIGHT/...
A WEAK SURFACE PRESSURE PATTERN WILL REMAIN OVER OUR FORECAST
AREA (FA) WITH A RELATIVELY DRY ATMOSPHERE...ENSURING FAIR
WEATHER. FORECAST SOUNDINGS CONTINUE TO INDICATE A DRY AND CAPPED
ATMOSPHERE...ALTHOUGH A FEW SHALLOW DIURNAL SHOWERS POSSIBLE.
GUIDANCE TRENDING A LITTLE HIGHER ON MAX TEMPS. PATCHY FOG
POSSIBLE THROUGH EARLY THIS MORNING. UPPER ENERGY AND REMNANT
CIRCULATION OF FORMER TS ERIKA...AND ASSOCIATED
MOISTURE...ROTATING AROUND THE UPPER HIGH STILL APPEARS WILL BE
SHUNTED TO THE EAST AND REMAIN SOUTH OF OUR FORECAST AREA AS
MIDWEST UPPER TROUGH SHIFTS SE TOWARDS THE MID ATLANTIC.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
UPPER RIDGE WILL SHIFT WEST OVER FLORIDA AND THE EASTERN
GULF...WHILE UPPER TROUGH REMAINS OVER THE EAST COAST...WITH A
SERIES OF DISTURBANCES MOVING THROUGH. MODELS INDICATE A SLIGHT
INCREASE IN MOISTURE...WHICH ALONG WITH SOME UPPER LIFT AND
DIURNAL HEATING...APPEARS TO PROVIDE A SLIGHT CHANCE OF MAINLY
DIURNAL SHOWERS AND THUNDERSTORMS.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THOUGH DIFFERENCES REMAIN BETWEEN GFS AND ECMWF ON SPECIFICS AND
TIMING...MODELS CONTINUE TO GENERALLY INDICATE BACK DOOR FRONT
MOVING INTO OR THROUGH THE REGION...WITH CLOSED LOW ALOFT AND A
LOW LEVEL EASTERLY FLOW OFF THE ATLANTIC LEADING TO INCREASING
ATMOSPHERIC MOISTURE AND POPS...AND TREND TOWARDS LOWER TEMPS.
WILL MAINTAIN BLEND OF GUIDANCE.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
WEAK HIGH PRESSURE AT THE SURFACE AND A BUILDING UPPER RIDGE
ALOFT...ALONG WITH A GENERALLY DRY AIR MASS SHOULD LEAD TO AN
UNEVENTFUL WEATHER DAY. HOWEVER...STRONG RADIATIONAL COOLING EARLY
THIS MORNING HAS ALREADY RESULTED IN MVFR VSBYS AT AGS AND EXPECT
MVFR/IFR VSBYS AT AGS AND EVENTUALLY LATER AT OGB. HRRR CEILING
FORECAST INDICATES SOME POSSIBLE LIFR CIGS MOVING INTO OGB AROUND
10-11Z BUT NO OTHER GUIDANCE SHOWING THIS AND WILL LEAVE OUT OF
THE FORECAST AT THIS TIME. LIGHT TO CALM WINDS THROUGH MID MORNING
THEN LIGHT AND VARIABLE WINDS EXPECTED WITH A PREVAILING SOUTHERLY
COMPONENT TO THE WINDS. PWAT VALUES AROUND 1.5 INCHES AND LACK OF
UPPER FORCING SUGGESTS CONVECTION PROBABILITIES ARE LOW AND WILL
NOT BE INCLUDED IN THE FORECAST.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN MAINLY EARLY
MORNING WITH FOG. BY LATE IN THE EXTENDED PERIOD...AFTERNOON AND
EVENING SCATTERED SHOWERS OR THUNDERSTORMS WILL BE POSSIBLE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
149 AM EDT WED SEP 2 2015
.SYNOPSIS...
AN UPPER-LEVEL RIDGE WILL GRADUALLY SHIFT EAST TOWARDS FLORIDA...
WHILE AN UPPER TROUGH WILL SHIFT SE FROM THE OHIO VALLEY TO
OFFSHORE THE MID ATLANTIC COAST. THIS WILL ENSURE THAT A
RELATIVELY DRY ATMOSPHERE WILL REMAIN IN PLACE OVER OUR REGION
THROUGH LATE WEEK...WITH SOME INCREASE IN MAX TEMPS. INDICATIONS
OF A BACK DOOR FRONT AND INCREASING MOISTURE MAY SPELL INCREASING
CHANCES FOR PRECIPITATION BY THIS WEEKEND...ALONG WITH SLIGHTLY
COOLER TEMPS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
A WEAK SURFACE PRESSURE PATTERN WITH RIDGING ALOFT WILL DOMINATE
THROUGH TONIGHT. DEEP MOISTURE WILL REMAIN SOUTHEAST OF THE AREA.
SATELLITE TRENDS SUPPORT HIGH CLOUDINESS MAINLY IN THE SOUTHEAST
SECTION OF THE FORECAST AREA TONIGHT. PATCHY FOG SHOULD OCCUR
DURING THE EARLY MORNING HOURS MAINLY IN THE RIVER VALLEYS. THE
TEMPERATURE GUIDANCE WAS CONSISTENT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
UPPER RIDGE WILL SHIFT WEST OVER FLORIDA AND THE EASTERN
GULF...WHILE MIDWEST CLOSED LOW OPENS AND SHIFTS SE TOWARDS THE
MID ATLANTIC COAST. UPPER ENERGY...CURRENTLY ALONG THE WEST COAST
OF FLORIDA MOVING NORTHEAST...AND MOISTURE TO OUR SOUTH APPEARS
WILL GET SUPPRESSED AND EJECTED TO THE EAST/SE...ALONG COASTAL
GEORGIA AND SOUTH CAROLINA...REMAINING SOUTHEAST OF OUR FA.
RELATIVELY DRY AIR APPEARS WILL REMAIN IN PLACE OVER OUR
FA...THOUGH SOME SLIGHT INCREASE IN MOISTURE NOTED. SLIGHT CHANCE
MAINLY DIURNAL POPS APPEARS OK. TEMPERATURES WARMING THE NEXT
COUPLE OF DAYS INTO THE MID 90S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
12Z GFS SIMILAR WITH 00Z ECMWF WITH SHIFTING UPPER LEVEL LOW FROM
THE WESTERN GULF OF MEXICO EAST INTO THE SOUTHEASTERN
STATES/CAROLINAS OVER THE WEEKEND INTO EARLY NEXT WEEK. EXPECT AN
INCREASE IN MOISTURE DURING THE PERIOD. ENSEMBLE POP GUIDANCE
SUPPORTS CHANCE POPS AT LEAST THROUGH THE WEEKEND. GFS DEVELOPING
WEAK LOW PRESSURE ALONG CAROLINA/GEORGIA COAST BY MONDAY BUT ECMWF
WEAKER AND MOISTURE MAINLY SOUTH OF THE AREA WITH SURFACE RIDGE
BUILDING SOUTH FROM MID ATLANTIC STATES. TEMPERATURES NEAR
CLIMATOLOGY NORMALS.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
WEAK HIGH PRESSURE AT THE SURFACE AND A BUILDING UPPER RIDGE
ALOFT...ALONG WITH A GENERALLY DRY AIR MASS SHOULD LEAD TO AN
UNEVENTFUL WEATHER DAY. HOWEVER...STRONG RADIATIONAL COOLING EARLY
THIS MORNING HAS ALREADY RESULTED IN MVFR VSBYS AT AGS AND EXPECT
MVFR/IFR VSBYS AT AGS AND EVENTUALLY LATER AT OGB. HRRR CEILING
FORECAST INDICATES SOME POSSIBLE LIFR CIGS MOVING INTO OGB AROUND
10-11Z BUT NO OTHER GUIDANCE SHOWING THIS AND WILL LEAVE OUT OF
THE FORECAST AT THIS TIME. LIGHT TO CALM WINDS THROUGH MID MORNING
THEN LIGHT AND VARIABLE WINDS EXPECTED WITH A PREVAILING SOUTHERLY
COMPONENT TO THE WINDS. PWAT VALUES AROUND 1.5 INCHES AND LACK OF
UPPER FORCING SUGGESTS CONVECTION PROBABILITIES ARE LOW AND WILL
NOT BE INCLUDED IN THE FORECAST.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN MAINLY EARLY
MORNING WITH FOG. BY LATE IN THE EXTENDED PERIOD...AFTERNOON AND
EVENING SCATTERED SHOWERS OR THUNDERSTORMS WILL BE POSSIBLE.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1220 AM CDT WED SEP 2 2015
...Update to aviation forecast discussion...
.SHORT TERM...(THIS EVENING THROUGH Wednesday)
ISSUED AT 339 PM CDT TUE SEP 1 2015
The upper levels show a broad upper ridge over the eastern CONUS
with a longwave trough just making its way into the Pacific
Northwest. Currently, most Radar sites across the Central Plains
remain quiet with only some rain showers over southeastern South
Dakota. Cloud tops have progressively cooled throughout the day
indicating that storms have been dissipating. This area of showers
appears to be in advance of a mid to upper level low amplitude
shortwave that is showing signs of weakening with decreasing
vorticity as it lifts further to the northeast from the lee trough
region of the Rockies.
Daytime mixing has allowed for some gusty winds at the surface today
as we are still under plenty of sunshine over northeastern KS. This
is expected to continue until tonight as winds calm as we begin to
lose insolation and the source of heating at the surface. Still
expecting that the previously mentioned shortwave will have at least
minor impacts tonight over north central and northeastern KS
tonight into the early morning hours Wednesday. Most short-term
high resolution guidance, such as the HRRR and RAP, suggest that
weak isentropic lift at around 310K level and a little extra
enhancement from the LLJ around 850mb will help create some small
areas of precip. With at least some midlevel instability due to
the remnants of the shortwave, there could be some elevated
thunderstorms. It is possible with drier low-levels per NAM and
RAP soundings that there could be some areas of stronger winds
with the more enhanced areas of thunderstorms and precip.
Expecting that tomorrow will be similar to today. As the clouds
from over night clear, expect mixing to occur once again with
highs climbing into the low 90s. Depending on how many clouds
remain, temps may need to be revised up a bit. As for lows
tonight, do expect temps to reach lower 70s which is up a bit due
to the expected cloud cover overnight.
.LONG TERM...(Wednesday NIGHT THROUGH Tuesday)
ISSUED AT 339 PM CDT TUE SEP 1 2015
Wednesday night through Friday afternoon...More of the same sensible
weather with highs in the 90s and lows in the 70s. Plume of
moisture continues to move into the four corners and southern and
Central Rockies as the western trof absorbs tropical energy from
near Baja. Weak wave may generate some isolated overnight showers
or a storm northwest late Wednesday night into early Thursday
morning, otherwise the ridge noses northward and keeps most of the
area dry and warm for the mid term period.
Friday night through Tuesday...Friday night and Saturday look to
be dry, before chances for precipitation start to increase Sunday
through Tuesday. An upper level system moving over the NW CONUS
Saturday will progress east along with an associated cold front.
With southerly winds advecting ample moisture into the region and
an advancing cold front, expect showers and storms to develop in
NE Kansas mainly early Monday morning through Tuesday. Models also
seem to be in better agreement with this timing. Cooler
temperatures are expected as that front passes, with lows in the
mid 60s Monday night and highs topping out in the low 80s on
Tuesday.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Wednesday NIGHT)
ISSUED AT 1219 AM CDT WED SEP 2 2015
For the 06z TAFs, VFR conditions are expected through the period.
Expect some isolated to scattered showers and isolated
thunderstorms near the TAF sites overnight into Wednesday
morning. With the low-level jet axis centered over central KS tonight, there is the
potential for some brief low-level wind shear concerns, especially
near KMHK as it is located closer to this increasing low-level jet.
Cannot rule out the potential for some borderline low-level wind
shear concerns near KTOP/KFOE so will continue to monitor this
potential as well. Otherwise, expect precipitation to exit the TAF site
through the morning hours with increasing southerly winds through
the afternoon.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Drake
LONG TERM...67/Heller
AVIATION...Hennecke
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
116 AM EDT WED SEP 2 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 438 PM EDT TUE SEP 1 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW WSW FLOW INTO THE UPPER
GREAT LAKES. SOME DISTURBANCES ARE NOTED IN THE FLOW...ONE IS IN NE
MN AND THE OTHERS ARE IN SE SD/NE NEBRASKA. DESPITE PRESENCE OF
SHORTWAVE NEARBY AND MLCAPES OF 1500-2500J/KG...NO SHRA OR TSTMS
HAVE DEVELOPED YET THIS AFTN. PER VIS SATELLITE IMAGERY...THERE IS
AN AREA OF WHAT LOOKS LIKE ENHANCED CU DEVELOPMENT FROM MENOMINEE
COUNTY TO ERN MARQUETTE COUNTY AND THEN E TO NRN LUCE COUNTY IN
VCNTY OF LAKE BREEZE OFF LAKE MICHIGAN. TO THE W...SCT
-SHRA/SPRINKLES THAT WERE NEAR/JUST OFFSHORE OF WRN UPPER MI THIS
MORNING HAVE MADE LITTLE EASTWARD PROGRESS AND ARE DIMINISHING IN
COVERAGE. IT`S BEEN ANOTHER UNCOMFORTABLY HOT/HUMID DAY. DWPTS RANGE
FROM THE MID 60S TO LWR 70S WITH TEMPS GENERALLY BTWN 80F AND 90F.
COOLEST CONDITIONS (UPPER 60S/LWR 70S) ARE AT LAKESIDE LOCATIONS
ALONG LAKE MICHIGAN E OF KESC.
WITH THE LACK OF CONVECTION SO FAR THIS AFTN...POTENTIAL FOR
SHRA/TSTM DEVELOPMENT DOESN`T LOOK PROMISING. IF SHRA/TSTMS DO
FORM...IT LOOKS LIKE THE BEST POTENTIAL WILL BE IN THE VCNTY OF THE
LAKE MICHIGAN LAKE BREEZE WHERE CU LOOKS BETTER DEVELOPED ATTM.
RECENT HRRR RUNS POINT TOWARD THAT POSSIBILITY. NOTHING MUCH HIGHER
THAN SCHC POPS WILL UTILIZED INTO THE EARLY EVENING HRS. UPSTREAM
SHORTWAVES OVER SD/NEBRASKA WILL DRIFT NE DURING THE NIGHT...AND
PROBABLY SHOULDN`T POSE A RISK FOR PCPN OVERNIGHT. SOME OF THE DRIER
AIR IN NRN MN WHERE DWPTS HAVE DROPPED OFF AS LOW AS THE UPPER 40S
WILL TRY TO MAKE SOME INROADS INTO UPPER MI DURING THE NIGHT...BUT
GIVEN WEAK LOW-LEVEL WIND FIELDS AND AREAS OF FOG OVER LAKE
SUPERIOR...LITTLE OR NONE OF THIS DRIER AIR SHOULD BE REALIZED HERE.
END RESULT...SHOULD BE ANOTHER NIGHT WITH FOG AND STRATUS
DEVELOPMENT IN MANY AREAS.
IT APPEARS THAT WITH UPSTREAM SHORTWAVES MOVING INTO WI/UPPER MI
WED...THERE SHOULD BE A BETTER POTENTIAL OF SHRA/TSTM DEVELOPMENT.
AS OPPOSED TO THE PCPN POTENTIAL TODAY...MODEL CONSENSUS IS MUCH
BETTER FOR SOME PCPN TO OCCUR ON WED...MAINLY OVER THE INTERIOR W
HALF WHERE INSTABILITY WILL BE GREATER. FOR NOW...OPTED TO RAISE
POPS INTO THE LOW/MID RANGE CHC CATEGORY TOWARD THE WI BORDER. IT
WILL BE A LITTLE COOLER WED...ESPECIALLY NEAR LAKE SUPERIOR WHERE
LAKE BREEZE WILL BE MORE ACTIVE THAN TODAY. DWPTS MIGHT BE A LITTLE
LOWER...BUT CONDITIONS WILL STILL BE UNCOMFORTABLY HUMID.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 351 PM EDT TUE SEP 1 2015
AT 00Z THURSDAY A SHORTWAVE WILL BE SET UP ACROSS UPPER MI AND
WI...RIDING THE N EDGE OF THE LARGER 500MB RIDGE SET UP ACROSS MUCH
OF THE CENTRAL U.S.
AS A RESULT...WILL START OFF WITH SLIGHT CHANCE POPS SLOWLY EXITING
SE WEDNESDAY NIGHT...WITH MAINLY DRY WEATHER THEN FIGURED THURSDAY
THROUGH AT LEAST FRIDAY AS THE 500MB RIDGE BUILDS BACK ACROSS THE
UPPER GREAT LAKES. 80S STILL LOOK ON TRACK FOR TEMPS THROUGH
SATURDAY...IF NOT SUNDAY TOO. THERE WILL BE SLIGHT DIFFERENCES EACH
DAY...BUT MAINLY A BETTER PUSH OF AIR OFF LAKE MI WHERE THEY WILL BE
HELD IN THE 70S.
A LOW EJECTING OUT OF THE PACIFIC NW WILL SWING TO THE S CENTRAL
CANADA AND THE DAKOTAS BY 12Z MONDAY...WITH A BREAKDOWN OF THE UPPER
LEVEL RIDGE OVER THE UPPER GREAT LAKES. BEST CHANCE OF RAIN LOOKS TO
BE LATER SUNDAY NIGHT INTO MONDAY. THE LATEST ECMWF SHOWS ONLY
LIMITED PRECIP REMAINING AS THE SYSTEM MOVES E DURING THE DAY
MONDAY. LOOK FOR TEMPERATURES TO FALL BACK TO NEAR NORMAL FOR HIGHS
MONDAY...AND THEN QUITE A CHANGE FOR TUESDAY WITH HIGHS CURRENTLY
ONLY FCST TO BE IN THE MID TO UPPER 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 113 AM EDT WED SEP 2 2015
FOG WILL BE AN ISSUE OVERNIGHT WITH VLIFR CONDITIONS EXPECTED AT ALL
SITES THROUGH SUNRISE. IMPROVEMENT TO VFR WILL OCCUR AROUND MID
MORNING ON WED. KIWD HAS THE BEST CHANCE AT SEEING SOME THUNDER AND
HAVE VCSH AND VCTS TO COVER FOR WED MORNING INTO WED AFTERNOON.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 438 PM EDT TUE SEP 1 2015
SUMMER PATTERN WILL DOMINATE THE UPPER GREAT LAKES THRU THE WEEK
WITH WINDS ON LAKE SUPERIOR UNDER 20KT. FOR MUCH OF THE TIME...
WINDS WILL BE UNDER 15KT. AT SOME POINT OVER THE WEEKEND...LIKELY
LATE IN THE WEEKEND...PRES GRADIENT WILL TIGHTEN AHEAD OF AN
APPROACHING COLD FRONT. THIS WILL LEAD TO AN UPTICK IN WINDS WITH A
BETTER POTENTIAL FOR GUSTS TO REACH THE 20-30KT RANGE. FINALLY...FOG
MAY BE AN ISSUE OVER AT LEAST PORTIONS OF THE LAKE FOR THE NEXT
SEVERAL DAYS UNDER WARM/HUMID AIR MASS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 8 AM EDT THIS MORNING FOR LMZ248-250.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1218 AM CDT WED SEP 2 2015
.UPDATE...
ISSUED AT 1218 AM CDT WED SEP 2 2015
NO CHANGES MADE...FORECAST IS ON TRACK.
UPDATE ISSUED AT 939 PM CDT TUE SEP 1 2015
THE 22-01 UTC HRRR ITERATIONS CONTINUE TO EXPAND THE COVERAGE OF
FOG TO MOST LOCATIONS ALONG AND EAST OF US HIGHWAY 85 LATE TONIGHT
INTO WEDNESDAY MORNING AS 60S F DEWPOINTS CONTINUE TO ADVECT
NORTH-NORTHWEST THIS EVENING. CERTAINLY CANNOT RULE OUT A
POTENTIAL DENSE FOG ADVISORY LATER TONIGHT GIVEN THE SIGNAL IN THE
HRRR.
UPDATE ISSUED AT 554 PM CDT TUE SEP 1 2015
DID ADD A MENTION OF FOG TO MUCH OF CENTRAL NORTH DAKOTA TONIGHT
AS 60S F DEWPOINTS CONTINUE TO ADVECT NORTH EARLY THIS
EVENING...WITH LIGHT WINDS AND CLEAR SKIES THROUGH THE OVERNIGHT.
THE 21 UTC HRRR AND 18 UTC NAM NEST SUPPORT THIS POTENTIAL VIA
THEIR REDUCED VISIBILITY FORECASTS ACROSS CENTRAL NORTH DAKOTA
LATE TONIGHT INTO EARLY WEDNESDAY MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 310 PM CDT TUE SEP 1 2015
THIS AFTERNOON...A WEAK SURFACE LOW PRESSURE TROUGH AND
ASSOCIATED WARM FRONT OVER CENTRAL SOUTH DAKOTA WAS A REFLECTION
OF A WEAKENING SHORT WAVE TROUGH ALOFT. THIS FEATURE IS FORECAST
TO MEANDER NORTHEAST WHILE DIMINISHING WITH TIME. SOUTHERLY LOW
LEVEL FLOW OVER THE WARM FRONT WILL TRANSFER MOISTURE NORTH INTO
THE JAMES RIVER VALLEY WHERE SEVERAL HIGH RESOLUTION MODELS AS
WELL AS THE GFS/NAM FORECAST SOME CONVECTION OVERNIGHT. WILL NEED
SOME TIME TO DEVELOP THIS SCENARIO SO DELAYED THE ONSET OF
CONVECTION UNTIL MIDNIGHT. OTHERWISE THIS FORCING WILL END/SHIFT
TO THE EAST ON WEDNESDAY. SKIES WILL BE MOSTLY SUNNY WEDNESDAY.
WITH A BROAD THERMAL RIDGE OVER EASTERN MONTANA AND NORTH DAKOTA
HIGHS WILL WARM WELL INTO THE 90S. HUMIDITY WILL BE LOW WITH
AFTERNOON VALUES REACHING 15 PERCENT WEST. THE MAJOR MISSING
COMPONENT WAS WINDS FOR FIRE WEATHER CONCERNS. WINDS WILL REMAIN
BELOW 15 MPH FOR THE MOST PART WEDNESDAY AFTERNOON.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 310 PM CDT TUE SEP 1 2015
CONTINUED VERY WARM WEDNESDAY INTO THURSDAY...FOLLOWED BY A
SIGNIFICANT PATTERN CHANGE FOR THE UPCOMING HOLIDAY WEEKEND.
STRONG UPPER LEVEL LOW DROPPING INTO THE PACIFIC NORTHWEST
WEDNESDAY WILL BECOME AN OPEN WAVE AND DEEPEN OVER THE WEST COAST
THROUGH SATURDAY. DURING THIS TIME NORTH DAKOTA WILL REMAIN ON THE
WESTERN EDGE OF THE UPSTREAM RIDGE AXIS...KEEPING VERY WARM AND
DRY AIR OVER THE STATE. HIGHS THURSDAY WILL ONCE AGAIN REACH INTO
THE 90S MANY LOCATIONS...WITH 80S NORTHWEST IN THE WAKE OF A SLOW
MOVING FRONTAL BOUNDARY. BY THURSDAY NIGHT EMBEDDED S/WV IMPULSES
WILL APPROACH THE REGION...AND WHEN COUPLED WITH THE BOUNDARY WILL
RESULT IN CHANCES FOR SHOWERS/THUNDERSTORMS WEST TO EAST DURING
THE NIGHT.
FRIDAY-SATURDAY THE WEST COAST UPPER TROUGH BEGINS TO MOVE FARTHER
INLAND AND WILL DIRECT A SERIES OF SHORTWAVE ENERGY IMPULSES ACROSS
THE NORTHERN PLAINS. THE EXPECTED INCREASE IN CLOUD COVER AND CAA
IN THE WAKE OF THE SFC FRONT WILL RESULT IN MUCH COOLER
TEMPERATURES...WITH HIGHS DROPPING INTO THE MID 60S NORTHWEST TO
LOW 80S OVER THE SOUTHERN JAMES RIVER VALLEY BY SATURDAY. SATURDAY
NIGHT INTO SUNDAY THE BASE OF THE TROUGH LIFTS NORTHEASTWARD INTO
THE NORTHERN PLAINS...REACHING SOUTHERN CANADA BY SUNDAY NIGHT.
THIS TIME PERIOD (FRIDAY-SUNDAY) WILL SEE VERY GOOD CHANCES FOR
SHOWERS AND THUNDERSTORMS.
A MORE ZONAL FLOW SETS UP EARLY NEXT WEEK AND SHOULD RESULT IN
MAINLY DRY CONDITIONS AND SOME TEMPERATURE RECOVERY AS WE PROGRESS
INTO THE MIDDLE PORTIONS OF THE WORK WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1218 AM CDT WED SEP 2 2015
AREAS OF FOG ARE IN THE FORECAST ACROSS MOST OF WESTERN AND
CENTRAL NORTH DAKOTA THIS MORNING. KJMS AND KBIS ARE MOST LIKELY
TO BE IMPACTED...WITH IFR/LIFR VISIBILITY POSSIBLE. KMOT AND KDIK
MAY BE ON THE FRINGE OF THE POTENTIAL FOG BANK. ONCE THE FOG BURNS
OFF THROUGH THE MORNING...VFR CONDITIONS ARE EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AC
SHORT TERM...WAA
LONG TERM...NH
AVIATION...AC
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1141 PM CDT TUE SEP 1 2015
.UPDATE...
ISSUED AT 1136 PM CDT TUE SEP 1 2015
OTHER THAN A PATCH OF MID LEVEL CLOUDS OVER THE CENTRAL DAKOTAS NO
INDICATIONS YET OF ANY CONVECTIVE DEVELOPMENT. LOW LEVEL JET
REMAINS FOCUSED ON SW MN WHERE ONGOING DEEP CONVECTION EXISTS.
WILL MAINTAIN LOW POPS AS WEAKER JET DEVELOPING OVER S CENTRAL ND.
NO CHANGES TO CURRENT FORECAST.
UPDATE ISSUED AT 941 PM CDT TUE SEP 1 2015
THUNDER CHANCES STILL THE CHALLENGE TONIGHT. THE HRRR WHICH WAS
OVERLY AGGRESSIVE IN DEVELOPING STORMS OVER OUR WESTERN FA HAS NOW
BACKED OFF AND FOCUSING DEVELOPMENT OVER SW MN WHERE THE MORE
PROMINENT LOW LEVEL JET IS TAKING SHAPE. A FEW OF THE SHORT RANGE
MODELS CONTINUE WITH SOME MODEST DEVELOPMENT LATER TONIGHT SO WILL
KEEP SLIGHT CHANCES GOING AS NOCTURNAL DEVELOPMENT SOMETIMES
FICKLE. BEST LOW LEVEL MOISTURE FLUX IS OVER THE WESTERN FA SO
HAVE ADDED SOME PATCHY FOG TO THIS AREA AS A START.
UPDATE ISSUED AT 645 PM CDT TUE SEP 1 2015
NO CHANGES NEEDED THIS UPDATE PERIOD.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 325 PM CDT TUE SEP 1 2015
500 MB SHORT WAVE NOTED IN SOUTHEASTERN SOUTH DAKOTA MOVING
NORTHEAST. A BAND OF SHOWERS ARE WITH THIS SYSTEM. FOR TONIGHT
QUESTION IS PRECIP CHANCES OVERNIGHT INTO WED MORNING MAINLY FOR
NE ND INTO NW MN. FOR THE PAST COUPLE OF DAYS MODELS HAVE
INDICATED THREAT FOR SOME CONVECTION TO DEVELOP NR 06Z IN THE MID
RRV AND THE MOVE NORTHEAST THROUGH LAKE OF THE WOODS REGION BY
12Z. 12Z MODELS TODAY SHOW TO SOME DEGREE THE SAME THING...BUT
MORE GFS IN THIS CASE AS MOST SHORT RANGE MODELS SUCH AS THE HRRR
AND RAP DONT SHOW (AT LEAST WITH MIDDAY AND EARLY AFTN RUNS).
THERE IS AN IMPRESSIVE LOW-850 MB MOISTURE RETURN THIS EVENING-
OVERNIGHT. SEEING 70 DEW PTS ALONG THE SD/ND BORDER INTO THE
ALEXANDRIA AREA WHILE MOST OF OUR FCST AREA HAS DEW PTS IN THE
50S. SO WILL SEE A MOISTURE SURGE TONIGHT AND INSTABILITY INCREASE
IN THE 850 MB LAYER 06Z-12Z PERIOD WHEN A FEW HUNDRED 850 MB CAPE
AVAILABLE. PROBLEM IS LOW LEVEL JET IS VERY WEAK 20 KTS MAYBE. BUT
WILL SIDE WITH CONSISTENCY AND KEEP LOW POPS IN BUT HAVE THEM
06Z-12Z....EXTENDING THEM A FEW HOURS PAST 12Z IN LAKE OF THE
WOODS. WEDNESDAY WILL BE MUCH MORE HUMID AND WARM.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 325 PM CDT TUE SEP 1 2015
HOT AND HUMID ON THURSDAY WITH MID 80S EAST TO LOW 90S WEST. WILL
MAINTAIN A LOW THREAT FOR PRECIP LATE THURSDAY NIGHT IN ERN
ND...THEN KEEP CHC POPS ON FRIDAY. UNCERTAIN HOW EVENT WILL PLAY
OUT BUT WILL HAVE SEVERAL SHORT WAVES AND SFC LOWS MOVE NORTHEAST
ALONG A FRONTAL BOUNDARY WHICH WILL BE OVER OR NEAR OUR AREA. EACH
ONE GIVING GOOD CHANCES FOR SHOWERS AND THUNDERSTORMS STARTING
LATE FRIDAY. DAY TO DAY TIMING OF COURSE IS DIFFICULT AT THIS
STAGE.
SATURDAY TO TUESDAY...MODELS IN GOOD AGREEMENT WITH THE GENERAL
500MB SOUTHWEST FLOW ALOFT AND EVOLUTION WITH A CLOSED STRONG SHORT
WAVE MOVING OVER THE NORTHERN PLAINS EARLY NEXT WEEK. AS A RESULT AN
ACTIVE WEATHER PATTERN WITH SEVERAL ROUNDS OF CONVECTIVE ACTIVITY
CAN BE EXPECTED FOR THE REGION OVER THE HOLIDAY WEEKEND.
UNCERTAINTIES EXIST WITH THE TIMING AND PLACEMENT OF THE LEAD WAVE
AND THE STRONGER SHORT WAVE ON MONDAY. CURRENTLY A LEAD WAVE IS
EXPECTED TO BRING A ROUND OF THUNDERSTORMS FRIDAY NIGHT WITH ANOTHER
ROUND SATURDAY NIGHT BEFORE THE THE LIGHTER WRAP AROUND PCPN ON
SUNDAY AFTN AND EARLY MONDAY. GIVEN THE AMPLE MOISTURE IN
PLACE...PWATS APPROACHING 2 INCHES...HEAVY RAIN WILL BE POSSIBLE
WITH ANY STORM. TEMPERATURES WILL BE WARMEST ON SATURDAY WITH LOW
80S IN THE SE HALF OF THE FA AND 70S IN THE NW...HIGHLY INFLUENCED
BY EXPECTED CLOUD COVER. A COOLER...CLOSER TO AVERAGE TEMP REGIME IS
EXPECTED WITH 70S SUNDAY TO TUE BEHIND DEPARTING SHORT WAVE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1136 PM CDT TUE SEP 1 2015
CONVECTIVE DEVELOPMENT OVERNIGHT REMAINS TOO UNCERTAIN TO MENTION
IN ANY TAFS. DID MENTION SOME BR DEVELOPMENT TOWARDS MORNING AS
LOW LEVEL MOIST AIR CONTINUES TO SPREAD NORTHWARD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...VOELKER
SHORT TERM...RIDDLE
LONG TERM...JK/RIDDLE
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
232 AM EDT WED SEP 2 2015
.SYNOPSIS...
ABOVE NORMAL TEMPERATURES FOR EARLY SEPTEMBER WILL CONTINUE INTO
NEXT WEEK WITH GRADUALLY DECREASING HUMIDITY LEVELS. OPPORTUNITIES
FOR RAINFALL WILL REMAIN LIMITED AS HIGH PRESSURE AT THE SURFACE
AND ALOFT DOMINATES THE REGIONAL WEATHER PATTERN.
&&
.NEAR TERM /UNTIL 10 AM THIS MORNING/...
EXPECT FOG TO EXPAND THROUGH THE PREDAWN HOURS AND MAY BE LOCALLY
DENSE IN SPOTS WITH VISIBILITY AOB 1/2SM. UPPER LEVEL DISTURBANCE
MOVG INTO WV MAY KICK OFF A VERY ISOLD SHOWER INVOF THE LAURELS AS
PER HRRR BUT CONFIDENCE AND POPS ARE QUITE LOW. BETTER CHC LATER
TODAY WITH THE HEATING CYCLE.
&&
.SHORT TERM /10 AM THIS MORNING THROUGH 6 PM THURSDAY/...
RIDGING STAYS IN PLACE TODAY. THERE IS A TINY DEPRESSION IN THE
OTHERWISE MASSIVE UPPER LEVEL RIDGE. THE DEPRESSION IS CURRENTLY
ASSOCD WITH A CLUSTER OF STORMS OVER CENTRAL IN. THIS DEPRESSION
SHOULD MOVE EASTWARD THRU THE UPPER OHIO VALLEY AND INTO THE MID
ATLANTIC.
BUT THAT FEATURE MAKES ONLY A SMALL DIP IN MID-LVL TEMPS AND TINY
DECREASE IN STABILITY ON WED. THIS MAY BE ENOUGH TO ALLOW SCT
SHRA/TSRA TO DEVELOP IN THE AFTN OVER THE HIGHER TERRAIN...MAINLY
THE LAURELS AND NRN MTNS. THE 30-40 POPS IN THE MTNS WILL PROBABLY
BE THE HIGHEST POPS WE DRAW FOR QUITE A FEW DAYS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
AN ANOMALOUS UPPER LEVEL RIDGE IS FORECAST TO DOMINATE THE LARGE
SCALE PATTERN OVER THE NORTHEASTERN CONUS INTO EARLY NEXT
WEEK...WITH HIGH PRESSURE TAKING CONTROL AT THE SFC. THIS PATTERN
WILL CONTINUE TO SUPPORT ABOVE-NORMAL TEMPERATURES AND VERY
LIMITED TO NO RAINFALL ACROSS CENTRAL PA THROUGH THE LABOR DAY
WEEKEND.
THE GFS REMAINS MORE BULLISH VS. THE ECMWF WITH CONVECTION ON
FRIDAY. HIGH PRESSURE INITIALLY CENTERED OVER QUEBEC WILL DROP SWD
OVER THE WEEKEND AND BRING SLIGHTLY COOLER AND DRIER/LESS HUMID AIR
INTO THE REGION. NO RISK OF RAIN AGAIN UNTIL PROBABLY NEXT
TUESDAY AS A COLD FRONT APPROACHES FROM THE GREAT LAKES/OH VLY.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
OVERNIGHT CONDITIONS WILL VARY. WHILE THERE HAS BEEN IFR FOG ALREADY
AT BRADFORD...IT HAS NOW SUNKEN INTO THE VALLEY. GIVEN THE LIGHT
WINDS AND LOW DEWPOINT DEPRESSIONS EXPECT VARIED IFR OR LOWER
VSBYS AND CIGS AT BFD THROUGH 13Z. AFTER CONDITIONS SHOULD IMPROVE
WITH VFR BY 14Z.
ELSEWHERE A HAZY WARM AND HUMID LATE SUMMER EVENING IS IN
PROGRESS. THE VFR CONDITIONS HAVE BEGUN TO GIVE WAY TO
RESTRICTIONS WITH IFR AT UNV AND MVFR AT AOO. THERE SHORT RANGE
MODELS ARE SHOWING A SLIGHT DRIER AIR MASS IN THE BOUNDARY
LAYER...WHICH COULD LIMIT OVERALL FOG POTENTIAL. HOWEVER IT
REMAINS EXPECTED THAT THE OVERNIGHT TO EARLY MORNING HOURS WILL
GIVE WAY TO DEVELOPING RESTRICTIONS AS PATCHY VALLEY FOG FORMS
ONCE AGAIN. THESE CONDITIONS SHOULD CONTINUE THROUGH 14Z...BEFORE
IMPROVING.
MORE CLEAR NIGHTS WITH AM VALLEY FOG AND MOSTLY SUNNY DAYS ARE
EXPECTED FOR THE NEXT SEVERAL DAYS.
OUTLOOK...
THU-SUN...PATCHY AM FOG POSS...MAINLY KIPT/KBFD. OTHERWISE VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...LA CORTE/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
209 AM EDT WED SEP 2 2015
.SYNOPSIS...
ABOVE NORMAL TEMPERATURES FOR EARLY SEPTEMBER WILL CONTINUE INTO
NEXT WEEK WITH GRADUALLY DECREASING HUMIDITY LEVELS. OPPORTUNITIES
FOR RAINFALL WILL REMAIN LIMITED AS HIGH PRESSURE AT THE SURFACE
AND ALOFT DOMINATES THE REGIONAL WEATHER PATTERN.
&&
.NEAR TERM /UNTIL 10 AM THIS MORNING/...
EXPECT FOG TO EXPAND THROUGH THE PREDAWN HOURS AND MAY BE LOCALLY
DENSE IN SPOTS WITH VISIBILITY AOB 1/2SM. UPPER LEVEL DISTURBANCE
MOVG INTO WV MAY KICK OFF A VERY ISOLD SHOWER INVOF THE LAURELS AS
PER HRRR BUT CONFIDENCE AND POPS ARE QUITE LOW. BETTER CHC LATER
TODAY WITH THE HEATING CYCLE.
&&
.SHORT TERM /10 AM THIS MORNING THROUGH 6 PM THURSDAY/...
RIDGING STAYS IN PLACE TODAY. THERE IS A TINY DEPRESSION IN THE
OTHERWISE MASSIVE UPPER LEVEL RIDGE. THE DEPRESSION IS CURRENTLY
ASSOCD WITH A CLUSTER OF STORMS OVER CENTRAL IN. THIS DEPRESSION
SHOULD MOVE EASTWARD THRU THE UPPER OHIO VALLEY AND INTO THE MID
ATLANTIC.
BUT THAT FEATURE MAKES ONLY A SMALL DIP IN MID-LVL TEMPS AND TINY
DECREASE IN STABILITY ON WED. THIS MAY BE ENOUGH TO ALLOW SCT
SHRA/TSRA TO DEVELOP IN THE AFTN OVER THE HIGHER TERRAIN...MAINLY
THE LAURELS AND NRN MTNS. THE 30-40 POPS IN THE MTNS WILL PROBABLY
BE THE HIGHEST POPS WE DRAW FOR QUITE A FEW DAYS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
AN ANOMALOUS UPPER LEVEL RIDGE IS FORECAST TO DOMINATE THE LARGE
SCALE PATTERN OVER THE NORTHEASTERN CONUS INTO EARLY NEXT
WEEK...WITH HIGH PRESSURE TAKING CONTROL AT THE SFC. THIS PATTERN
WILL CONTINUE TO SUPPORT ABOVE-NORMAL TEMPERATURES AND VERY
LIMITED TO NO RAINFALL ACROSS CENTRAL PA THROUGH THE LABOR DAY
WEEKEND.
THE GFS REMAINS MORE BULLISH VS. THE ECMWF WITH CONVECTION ON
FRIDAY. HIGH PRESSURE INITIALLY CENTERED OVER QUEBEC WILL DROP SWD
OVER THE WEEKEND AND BRING SLIGHTLY COOLER AND DRIER/LESS HUMID AIR
INTO THE REGION. NO RISK OF RAIN AGAIN UNTIL PROBABLY NEXT
TUESDAY AS A COLD FRONT APPROACHES FROM THE GREAT LAKES/OH VLY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
FOG HAS ALREADY CRASHED THE VIZ AT BRADFORD. ELSEWHERE A HAZY
WARM AND HUMID LATE SUMMER EVENING IS IN PROGRESS. THE VFR
CONDITIONS WILL GIVE WAY TO DEVELOPING RESTRICTIONS AS PATCHY
VALLEY FOG FORMS ONCE AGAIN TONIGHT.
MORE CLEAR NIGHTS WITH AM VALLEY FOG AND MOSTLY SUNNY DAYS ARE
EXPECTED FOR THE NEXT SEVERAL DAYS.
OUTLOOK...
THU-SUN...PATCHY AM FOG POSS...MAINLY KIPT/KBFD. OTHERWISE VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
414 AM CDT WED SEP 2 2015
.SHORT TERM (TODAY THROUGH THURSDAY)...THE MID LEVEL LOW/TROUGH IS
STILL HANGING AROUND THE TEXAS COAST PER THE WATER VAPOR IMAGERY.
THIS COMBINED WITH PWATS OF NEAR 2 INCHES DRAPED ALONG THE EASTERN
CWA WILL CONTINUE ISOLATED TO SCATTERED SHOWER AND THUNDERSTORM
DEVELOPMENT...FOCUSING ALONG THE COASTAL CONVERGENCE DURING THE
MORNING HOURS /ESPECIALLY TOWARD THE NORTHERN COASTAL BEND/...THEN
SHIFTING FARTHER INLAND WITH THE SEA BREEZE. HRRR AND TEXAS TECH
MODELS CONTINUE COASTAL ACTIVITY THROUGH THE EARLY AFTERNOON
/WITH TX TECH MODEL BEING THE MORE AGGRESSIVE OF THE TWO/ BEFORE
SHIFTING FARTHER INLAND...SO HAVE EXTENDED CHANCE POPS FARTHER
EAST IN THE AFTERNOON HOURS. ACTIVITY WILL WANE WITH THE LOSS OF
HEATING...BUT A SIMILAR SITUATION IS EXPECTED TO REDEVELOP LATER
TONIGHT THROUGH THURSDAY. TEMPERATURES WILL HEAVILY RELY ON ACTUAL
RAINFALL AND CLOUD COVERAGE...HOWEVER MAINTAINED RELATIVELY
PERSISTENT WITH TEMPS ACROSS THE EASTERN ZONES...BUT DID RAISE
TEMPS OUT WEST BY A FEW DEGREES.
&&
.LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...CONVECTIVE CHANCES
/ALBEIT RATHER LOW/ WILL CONTINUE TO BE PRIMARY FORECAST CHALLENGE
FOR THE LONG TERM PERIOD. UPPER LEVEL DYNAMICAL CONVECTIVE SUPPORT
WILL DIMINISH BY LATE THIS WEEK WITH PRIMARY CONVECTIVE CHANCES
BECOMING DIURNALLY SUPPORTED /COMMON PATTERN FOR THIS TIME OF YEAR/.
SUFFICIENT DEEP LAYER MOISTURE /PWATS GENERALLY 1.75 TO 2 INCHES/ IS
PROG TO PERSIST THROUGH MOST OF THE LONG TERM PERIOD. ISOLATED TO
SCATTERED CONVECTION IS PROG TO DEVELOP ACROSS MARINE AREAS AND THE
COASTAL COUNTIES THURSDAY NIGHT AS A NOCTURNALLY DRIVEN UNSTABLE
AIRMASS DEVELOPS ALONG THE COAST AND JUST OFFSHORE WITH SBCAPES PROG
TO BE AROUND 2500 J/KG. CONVECTIVE ACTIVITY /SCATTERED AT BEST/
SHOULD DEVELOP FURTHER IN AREAL COVERAGE ACROSS THE COASTAL PLAINS
AND NORTHERN COASTAL BEND BY MID MORNING FRIDAY WITH ACTIVITY THEN
SHIFTING INLAND DURING THE AFTERNOON. CONVECTIVE COVERAGE ON
SATURDAY IS EXPECTED TO BE MUCH MORE ISOLATED AS MID LEVEL TEMPS ARE
PROG TO INCREASE WITH STRENGTHENING RIDGING...THUS CAPPING THE
ATMOSPHERE TO AN EXTENT. EVEN WARMER MID LEVEL TEMPS ON SUNDAY
SHOULD KEEP MOST AREAS DRY. MID LEVEL RIDGE CENTER IS THEN PROG TO
SHIFT WESTWARD SLOWLY EARLY NEXT WEEK...ALLOWING FOR A RETURN OF
ISOLATED TO SCATTERED CONVECTION /AGAIN BEST CHANCES ALONG THE COAST
AND OFFSHORE AT NIGHT/MORNING AND INLAND DURING THE DAY/. ASIDE FROM
CONVECTION...ANOTHER ITEM OF CONCERN FOR THE LONG TERM PERIOD WILL
BE HEAT INDICES. A SURGE OF HIGHER NEAR SURFACE MOISTURE IS PROG TO
OCCUR FOR OVER THE UPCOMING HOLIDAY WEEKEND. AFTERNOON HEAT INDICES
OVER THE LABOR DAY WEEKEND ARE CURRENTLY EXPECTED TO RANGE FROM 105
TO 110 DEGREES WITH HIGH TEMPS IN THE MID 90S TO AROUND 100...AND
AROUND 90 AT THE BEACH. THOSE WITH OUTDOOR ACTIVITIES THIS WEEKEND
ARE URGED TO DRINK PLENTY OF WATER AND TO SEEK SHADE WHEN POSSIBLE.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 90 75 90 76 93 / 30 20 30 20 30
VICTORIA 89 73 89 74 93 / 30 30 40 20 30
LAREDO 98 76 98 78 100 / 10 10 20 10 10
ALICE 92 74 93 73 97 / 30 10 40 10 30
ROCKPORT 85 77 87 79 91 / 40 30 40 30 30
COTULLA 97 74 97 77 99 / 10 10 20 10 10
KINGSVILLE 90 75 91 76 96 / 30 20 40 10 20
NAVY CORPUS 85 77 87 79 91 / 40 30 40 20 30
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
CB/85...SHORT TERM
RH/79...LONG TERM
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1136 PM CDT TUE SEP 1 2015
.DISCUSSION...
06Z TAF DISCUSSION IN AVIATION SECTION.
&&
.AVIATION...
WATER VAPOR IMAGERY STILL SHOWING UPPER LOW OVER THE REGION BUT
LOOKS LIKE BEST LARGE SCALE ASCENT HAS MOVED EAST. MODELS STILL
SHOWING CONVECTION DEVELOPING IN THE MORNING HOURS AND MOVING
INLAND BUT HRRR RUNS HAVE BECOME LESS ROBUST WITH CONVECTIVE
DEVELOPMENT. THE LATEST 00Z NAM DID NOT INITIALIZE WELL WITH
CONVECTION BUT LOOKS LIKE WRF-ARW SEEMS TO BE ON TRACK. GFS KEEPS
CONVECTIVE DEVELOPMENT IN THE AFTERNOON. OVERALL LEAN A BIT MORE
ON THE HRRR/WRF TRENDS WHICH SUPPORT ON GOING FORECAST.
THIS MEANS MAINLY VFR CIGS TONIGHT EXCEPT WHERE CONVECTION
DEVELOPS. EXPECT CONVECTION ALONG THE COAST TO MOVE INLAND THROUGH
THE MORNING. ANY SHRA/TSRA SHOULD BE WEAKENING THROUGH THE
AFTERNOON.
39
&&
.PREV DISCUSSION... /ISSUED /
DISCUSSION...
SEE THE UPDATE DISCUSSION BELOW.
UPDATE...
THE ELONGATED UPPER LEVEL LOW PRESSURE TROUGH WAS OVER SE TX AT
MID EVENING. LOW PRESSURE IN THE FLOW WAS ALSO LOCATED BETWEEN
FREEPORT AND GALVESTON. THE MAJORITY OF THE RAINFALL WAS ALSO
LOCATED OFF TO THE EAST TOWARD THE LA COAST. THE LATEST HIGHER
RESOLUTION MODELS WERE FORECASTING REDEVELOPMENT MANLY ALONG AND
OFF THE COAST LATER TONIGHT...ALTHOUGH THE COVERAGE WAS LESS THAN
PREVIOUSLY ANTICIPATED. SLIGHTLY COOLER TEMPERATURES WERE ALSO IN
PLACE ACROSS THE AREA. BECAUSE OF THIS...UPDATED THE FORECAST AND
REVISED DOWN THE POPS...AND TWEAKED TEMPERATURES.
40
PREV DISCUSSION... /ISSUED /
DISCUSSION...
00Z TAF DISCUSSION IN AVIATION SECTION.
AVIATION...
UPPER LEVEL LOW OVER SE TX SUPPORTED SCT SHRA/TSRA MAINLY SOUTH
OF KIAH WHICH IMPACTED KGLS THE MOST. SHRA/TSRA ARE PRETTY CLOSE
TO BEING DONE WITH A FEW SHRA W OF KLBX. WILL NOT CARRY ANY
MENTION OF CONVECTION OVERNIGHT FOR THE TAFS AS BOUNDARY LAYER
LOSES HEATING AND HAS STABILIZED WITH CONVECTION.
TOMORROW WILL BE ANOTHER CHALLENGE WITH CONVECTION. TIMING OF
VCSH/VCTS FOR TOMORROW MORNING SIMILAR TODAY WITH ACTIVITY
DEVELOPING ALONG THE COAST AND PUSHING INLAND. HARD TO SAY HOW
MUCH THE ATMOSPHERE HAS BEEN STABILIZED WITH CONVECTION TODAY
SINCE UPPER LOW STILL SHOULD BE IN THE AREA AND PRECIP WATER
VALUES WILL BE HANGING AROUND 2 INCHES. QUITE POSSIBLE THAT
SHRA/TSRA COULD DEVELOP FARTHER INLAND BUT MORE ISO IN NATURE.
TAFS WILL MENTION VCSH DURING THE EARLY AFTERNOON BUT WAIT FOR 00Z
MODEL RUNS TO GET A BETTER HANDLE ON CONVECTIVE TRENDS TOMORROW.
39
PREV DISCUSSION... /ISSUED /
DISCUSSION...
SHOWER AND THUNDERSTORM COVERAGE HAS DECREASED ACROSS SOUTHEAST TEXAS
THIS AFTERNOON. PARTS OF THE AREA...ESPECIALLY IN AND AROUND GALVESTON
ISLAND...SAW SOME LOCALLY HEAVY RAINFALL OF 2 TO OVER 4 INCHES WHICH
LED TO SOME FLASH FLOODING. WHILE THE MID/UPPER LEVEL LOW APPEARS TO
HAVE MOVED OFF TO THE NORTHEAST...ANOTHER CIRCULATION CENTER HAS FORMED
IN/AROUND THE MATAGORDA BAY AREA. SOME SHOWERS AND THUNDERSTORMS HAVE
BEGUN TO DEVELOP IN ASSOCIATION WITH THIS FEATURE...AND THINK WE COULD
SEE SOME MORE DEVELOPMENT THIS EVENING AND OVERNIGHT IN/AROUND THIS
AREA. FOR THE NEXT SEVERAL DAYS...WILL GENERALLY CALL FOR LOWER POPS
WELL INLAND (WHERE MID/UPPER LEVEL HIGH PRESSURE MIGHT BEGIN TO BECOME
THE DOMINATE FEATURE) AND HIGHER POPS NEAR THE COAST AND OFFSHORE (WHERE
BOTH A MID/UPPER LEVEL TROF AXIS AND PRECIPITABLE WATER VALUES AROUND
2 INCHES WILL CONTINUE TO RESIDE). LOCALLY HEAVY RAINFALL COULD DEVELOP
AGAIN WITH THESE FUTURE STORMS...AND CANNOT RULE OUT FUNNEL CLOUD AND/OR
WATERSPOUT FORMATIONS TOO. IT WILL OBVIOUSLY BE WARMER WELL INLAND WITH
LESS CLOUD COVER AND FEWER STORMS...AND NOT AS WARM CLOSER TO THE COAST
AND OFFSHORE WHERE THE BULK OF CLOUDS AND STORMS WILL BE LOCATED. BY
THE END OF THE WEEK AND OVER THE HOLIDAY WEEKEND...IT LOOKS LIKE WE
WILL BE GETTING BACK INTO A MORE DIURNALLY DRIVEN PATTERN OF A CHANCE
OF MAINLY LATE MORNING THROUGH EARLY EVENING SHOWERS AND THUNDERSTORMS.
42
MARINE...
A FEW SHOWERS AND THUNDERSTORMS CONTINUE TO LINGER ACROSS THE MARINE
ZONES THIS AFTERNOON. HIGH RESOLUTION GUIDANCE SHOWS THAT A BRIEF
BREAK IN THIS ACTIVITY WILL BE POSSIBLE THIS EVENING TO LATE TONIGHT
BEFORE AN UPPER DISTURBANCE MOVES OVER THE NORTHWEST GULF OF MEXICO.
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP
ALONG THE COAST EARLY WEDNESDAY MORNING AND REMAIN THROUGH THE DAY
AS THIS HAPPENS... WITH HEAVY RAINFALL AND GUSTY WINDS ACCOMPANYING
THIS ACTIVITY. VISIBILITIES MAY BE LIMITED TO 1 NAUTICAL MILE OR
LESS AT TIMES DUE TO HEAVY RAINFALL. ALSO CANNOT RULE OUT AN
ISOLATED WATERSPOUT THREAT DURING THE DAY WITH AMPLE TROPICAL
MOISTURE AND A LIGHT WIND PROFILE IN PLACE ABOVE THE SURFACE. EXPECT
SHOWERS AND THUNDERSTORMS TO CLEAR THE MARINE AREAS SOMETIME
WEDNESDAY EVENING BUT PERIODS OF SHOWERS AND THUNDERSTORMS WILL
REMAIN WILL POSSIBLE THROUGH THE END OF THE WEEK. OTHERWISE... WEAK
TO OCCASIONALLY MODERATE ONSHORE FLOW IS EXPECTED TO PERSIST INTO
THE HOLIDAY WEEKEND WITH SEAS GENERALLY 1-3 FEET.
HUFFMAN
PREV DISCUSSION...
AVIATION...
FOR THE 18Z TAFS... MAIN AVIATION CONCERNS CENTER AROUND ONGOING
TSRA/SHRA ACTIVITY AT THE TERMINALS WITH ADDITIONAL DEVELOPMENT
EXPECTED AGAIN ON WEDNESDAY.
SCATTERED TO NUMEROUS THUNDERSTORMS ASSOCIATED WITH A MID TO
UPPER LEVEL DISTURBANCE CONTINUE TO MOVE ACROSS THE TERMINALS THIS
AFTERNOON. BULK OF ACTIVITY IS CONCENTRATED NEAR AND NORTH OF CXO
WITH AN ADDITIONAL BROKEN LINE CLEARING THE HOUSTON TERMINALS AND
SOUTHWARD. STARTING TO SEE ADDITIONAL ACTIVITY DEVELOP OVER THE
GULF AND THIS WILL NEED TO BE MONITORED FOR THE COASTAL SITES THIS
AFTERNOON. HAVE VCTS AT ALL TERMINALS THROUGH 21Z AS ACTIVITY
EXITS THE AREA... WITH ANOTHER ROUND OF SHRA/TSRA POSSIBLE AGAIN
EARLY WEDNESDAY MORNING OVER THE COASTAL WATERS AND SPREADING
NORTH INTO THE TERMINALS THROUGH WEDNESDAY AFTERNOON AS THE
AFOREMENTIONED DISTURBANCE DRAWS CLOSER TO THE REGION.
OTHERWISE... LIGHT AND VARIABLE TO LIGHT AND SOUTHERLY WINDS
EXPECTED FOR THE TERMINALS THROUGH THE PERIOD WITH VFR CONDITIONS
OUTSIDE OF TSRA/SHRA ACTIVITY. SOME STRONGER WIND GUSTS
APPROACHING 20 KNOTS WILL BE POSSIBLE IN CONVECTIVE ACTIVITY AS
WELL AS MVFR VISIBILITIES. COULD SEE A FEW HOURS OF MVFR
VISIBILITIES AT CXO AGAIN WEDNESDAY MORNING AS WELL AT CXO... BUT
ONLY INCLUDING A TEMPO MENTION ATTM.
HUFFMAN
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 72 91 73 94 73 / 10 30 20 30 10
HOUSTON (IAH) 72 88 73 92 73 / 20 50 30 40 20
GALVESTON (GLS) 78 87 79 88 79 / 40 60 40 50 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...40
AVIATION/MARINE...39
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
450 AM EDT WED SEP 2 2015
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH THE
END OF THE WEEK. UPPER LEVEL DISTURBANCES TRACKING THROUGH THE
RIDGING WILL RESULT IN WIDELY SCATTERED MAINLY DIURNAL SHOWERS
AND STORMS INTO FRIDAY. A WEAK BACKDOOR COLD FRONT WILL DROP
SOUTH THROUGH THE AREA BY THE END OF WEEK BRINGING SOMEWHAT DRIER
AND COOLER AIR FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 240 AM EDT WEDNESDAY...
OVERALL HOT AND HUMID WEATHER FOR EARLY SEPTEMBER TO PERSIST TODAY AS
SURFACE HIGH PRESSURE REMAINS IN PLACE ACROSS THE MOUNTAINS. HOWEVER
SHORTWAVE ENERGY IN THE FORM OF AN OPENING UPPER LOW ACROSS THE OHIO
VALLEY WILL RIDE SOUTHEAST THROUGH THE 5H RIDGE AND OVER THE NORTHERN
HALF OF THE AREA THIS AFTERNOON. THIS SHOULD RESULT IN BETTER LIFT
ESPCLY ALONG AND JUST SOUTH OF THE INTERSTATE 64 CORRIDOR EARLY ON AND
ACROSS THE EASTERN HALF THROUGH LATE IN THE DAY. LATEST GUIDANCE ALSO
SHOWING BETTER INSTABILITY WITH A LITTLE MORE COOLING ALOFT...BUT STILL
UNCERTAINTY WITH COVERAGE GIVEN OVERALL BROAD SUBSIDENCE IN PLACE UNDER
RATHER WARM 5H TEMPS. CURRENT SPC/RNK WRF SOLUTIONS ALONG WITH THE
LATEST HRRR REMAIN THE MOST WIDESPREAD WITH SHRA/TSRA NORTH HALF AND
ALONG THE BLUE RIDGE. THIS WHILE MOST OTHER SOLUTIONS INCLUDING
ENSEMBLES PRODUCING LESS INCLUDING ONLY WIDELY SCATTERED SHALLOW
CONVECTION MAINLY CONFINED FROM THE VIRGINIA HIGHLANDS EAST TO AROUND
KLYH FOR THE MOST PART. THEREFORE ALIGNED HIGHEST CHANCE POPS ACROSS
THE FAR NORTH WITH A PERIOD OF LOWER CHANCES SOUTH/EAST DURING MID/LATE
AFTERNOON AND ONLY ISOLATED COVERAGE FAR SW. GIVEN WEAK FLOW ALOFT NOT
EXPECTING MUCH OF A SEVERE THREAT BUT COULD SEE A BIT MORE CLUSTERING
OF SLOW MOVING CONVECTION RIGHT NEAR THE CORE OF THE UPPER WAVE LATE.
OTHERWISE LOOKING AT MAINLY PC WITH MID DECK EARLY...THEN MORE CU THIS
AFTERNOON WITH HIGHS AGAIN REACHING THE LOW 90S EAST AND WELL INTO THE
80S ELSEWHERE PENDING TIMING OF CONVECTIVE INITIATION.
IMPULSE PASSES THIS EVENING LEAVING THE REGION IN BETWEEN WAVES AND
UNDER SURFACE HIGH PRESSURE. THIS SHOULD ALLOW MOST CONVECTION TO FADE
BY MIDNIGHT GIVEN LOSS OF HEATING AND SOME OVERNIGHT CLEARING PER WEAK
NW FLOW ALOFT IN THE WAKE OF THE MID LEVEL SYSTEM. THUS KEEPING SOME
LOW END CHANCE POPS GOING MAINLY EAST THIS EVENING BEFORE TRENDING DRY
WITH FOG AGAIN OVERNIGHT. LOWS PERHAPS SLIGHTLY COOLER GIVEN SOME DROP
IN DEWPOINTS AND ESPCLY WHERE ANY COOLING EVENING RAINFALL OCCURS BUT
STILL MOSTLY LOW/MID 60S MOUNTAINS TO UPPER 60S EAST.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 415 AM EDT WEDNESDAY...
WEAK UPPER-LEVEL SHORT WAVE WILL BE DISSIPATING ACROSS NORTH
CAROLINA DRIFTING SLOWLY INTO THE SOUTHEAST STATES WHERE IT
APPEARS IT IS DESTINED TO BECOME A WEAK CUTOFF THAT WILL
RETROGRADE/LINGER ACROSS THE SOUTHEAST/MID-SOUTH INTO NEXT WEEK AS
A LARGE HIGH AMPLITUDE UPPER RIDGE CONTINUES TO BUILD FROM THE
SOUTH CENTRAL/CENTRAL U.S. INTO SOUTHEAST CANADA AND THE NORTHEAST
U.S. OVER THE TOP OF THE WEAK CUTOFF LOW. UPPER SUPPORT WILL BE
MINIMAL AT BEST WITH BEST DYNAMICS...WHAT THEY ARE...HAVING
DRIFTED SOUTH OF THE AREA. ANY CONVECTION WILL LARGELY BE THE
RESULT OF DIFFERENTIAL HEATING AND FOCUSED PRIMARILY ACROSS THE
WESTERN MOUNTAINS. REALLY CANNOT SUPPORT MUCH MORE THAN 30 POPS AT
BEST.
BY FRIDAY...A LARGE SURFACE HIGH DEVELOPING ACROSS THE NORTHEAST
U.S. UNDERNEATH THE MAMMOTH UPPER RIDGE WILL BEGIN TO PUSH A
BACKDOOR FRONT FROM THE MID-ATLANTIC SOUTHWESTWARD. UPPER DYNAMICS
ARE VERY WEAK...BUT A MARKED DEWPOINT GRADIENT WILL EXIST ALONG
THE SOUTHWESTWARD ADVANCING BOUNDARY AS VERY DRY AIR ADVECTS
SOUTHWEST INTO NORTHERN VA. THIS SHOULD BE SUFFICIENT TO SUPPORT
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS...WITH THE BEST
COVERAGE SHIFTING SOUTHWEST TOWARD EVENING. INSTABILITY IS QUITE
NOTABLE ACROSS THE REGION IN ADVANCE OF THIS BACKDOOR FRONT...SO
EVEN WITH WEAK DYNAMICS...WITH THE NOTED INSTABILITY AND PWATS IN
THE 1.5 TO 1.7 INCH RANGE...30-40 PERCENT POPS SEEMS REASONABLE.
FOR SATURDAY...THE BACKDOOR FRONT CONTINUES TO DRIFT SOUTHWEST AND
SHOULD BE LOCATED FROM CENTRAL WV THROUGH SOUTHWEST VA...NEAR THE
I-77 CORRIDOR...INTO CENTRAL NC. VERY DRY AIR IS NOTED ADVECTING
INTO THE REGION FROM THE NORTHEAST WITH DEWPOINTS DROPPING INTO
THE 50S AND PWATS FALLING TO NEAR 0.50 INCH ACROSS THE NORTHEAST
PART OF THE CWA. ANY CONVECTION SATURDAY SHOULD BE LIMITED TO THE
I-77 CORRIDOR AND POINTS WESTWARD...PRIMARILY DURING THE
AFTERNOON/EVENING.
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL THURSDAY AND FRIDAY
AHEAD OF THE BACKDOOR FRONT...WITH MAX TEMPS WELL INTO THE
80S...NEAR 90 ACROSS THE PIEDMONT. MIN TEMPS WILL HOLD MOSTLY IN
THE 60S TO EVEN NEAR 70 ACROSS THE PIEDMONT. THESE READINGS ARE
AROUND 5 AND 10 DEGREES ABOVE NORMAL...RESPECTIVELY. MOS GUIDANCE
HAS BEEN TRENDING TOO MUCH TOWARD CLIMATOLOGY...SO NEEDED TO NUDGE
UP MOST AREAS FROM 2-3 DEGREES TO BETTER MATCH WHAT HAS BEEN
OCCURRING RECENTLY.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 445 AM EDT WEDNESDAY...
THE FOCUS THROUGH THE PERIOD WILL BE ON THE AFOREMENTIONED WEAK
AND INCREASING BROAD UPPER LOW ANCHORED ACROSS THE SOUTHEAST/MID-
SOUTH PART OF THE U.S. OUR CWA WILL BE STUCK IN THE TRANSITION
ZONE BETWEEN THIS INCREASINGLY MOIST/UNSTABLE AIR MASS TO THE
SOUTH AND THE PERSISTING UPPER RIDGE AND ASSOCIATED
SUBSIDENCE/VERY DRY AND WARM AIR MASS ACROSS THE MID-ATLANTIC
REGION. SHOWER/THUNDERSTORM CHANCES WILL GRADUALLY CREEP NORTHWARD
THROUGH THE PERIOD...BUT LIKELY REMAIN CONFINED TO AREAS WEST OF
I-77 SUNDAY...THEN CREEP FURTHER NORTH TOWARD THE U.S. 460
CORRIDOR BY MONDAY AND MUCH OF THE CWA BY TUESDAY. THE BEST
CHANCES THROUGHOUT THE PERIOD WILL REMAIN ACROSS THE WESTERN NC
MOUNTAINS. THE MODELS HAVE CONTINUALLY DELAYED THE ARRIVAL OF A
FRONT TOWARD THE MID PART OF NEXT WEEK...AND WITH THE UPPER RIDGE
SANDWICHED IN BETWEEN THE LOW PRESSURE AREA TO THE SOUTH AND THE
STRONGER WESTERLIES ALONG THE CANADIAN BORDER...IT MAY BE SOME
TIME BEFORE IT ACTUALLY REACHES OUR AREA. HENCE...SUMMER APPEARS
DESTINED TO HANG ON MUCH OF NEXT WEEK.
MAX TEMPS SHOULD BE NEAR NORMAL AT THE BEGINNING OF THE
PERIOD...BUT PERHAPS STILL SLIGHTLY ABOVE NORMAL WEST OF I-77. MIN
TEMPS WILL REMAIN NEAR NORMAL TO SLIGHTLY ABOVE NORMAL FAR
SOUTHWEST. MAX AND MIN TEMPS WILL CREEP TO SLIGHTLY ABOVE NORMAL
LEVELS AGAIN AS WE MOVE INTO EARLY NEXT WEEK.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
AS OF 100 AM EDT WEDNESDAY...
OTHER THAN FOR DEBRIS MID/HIGH CLOUDS...FOG THE MAIN CONCERN
OVERNIGHT WITH POTENTIAL AGAIN GIVEN LESS CLOUDS OF SEEING THE
VALLEYS SUCH AS KLWB/KBCB DROP INTO LIFR/IFR FOR A PERIOD PRIOR TO
DAYBREAK. ALSO SOME FOG POSSIBLE AROUND KLYH-KDAN WHERE BRIEF MVFR
TO IFR POSSIBLE WHILE COVERAGE LOOKS QUITE SPOTTY AT KBLF WHERE
LIMITED TO JUST A VERY BRIEF INCLUSION OF MVFR CONDITIONS AROUND
DAWN.
FOR WEDNESDAY...SHOULD SEE ANY LOW CLOUDS/FOG FADE WITH THE ONSET
OF HEATING ALLOWING FOR VFR CONDITIONS TO QUICKLY RETURN BY MID
MORNING IF NOT SOONER. THEN EXPECT THE UPPER WAVE OVER THE OHIO
VALLEY TO SLOWLY SHIFT SOUTHEAST INTO VIRGINIA. THIS WILL ALLOW
MORE INSTABILITY WITH STEEPER LAPSE RATES AND LIFT. SHOWERS AND
STORMS WILL BE MORE SCATTERED WEDNESDAY AFTERNOON WITH BEST
FORCING ACROSS THE FOOTHILLS/PIEDMONT TO THE NEW RIVER VALLEY. AS
OF NOW WILL KEEP THE GOING VCTS AT KROA/KLYH AND KBCB AFTER
19Z/3PM...BUT THINK COVERAGE WILL BE LESS FURTHER WEST AND
SOUTHEAST...SO ONLY GOING WITH A VCSH AT KLWB-KBLF WHILE KEEPING
MENTION OUT OF KDAN.
OVERALL EXPECT VFR CONDITIONS WEDNESDAY WITH CIGS OF 4-6KFT WITH
TCU AND CB IN THE AFTERNOON.
EXTENDED AVIATION DISCUSSION...
THE FORECAST AREA WILL REMAIN IN A WEAKLY FORCED SYNOPTIC
ENVIRONMENT THROUGH THURSDAY...WITH CHANCES FOR DIURNAL
CONVECTION MAINLY FROM THE BLUE RIDGE WEST...AND SOME MVFR/IFR
FOG/STRATUS DEVELOPMENT AT NIGHT...ESPECIALLY AT KBCB AND KLWB.
FOR FRIDAY INTO SUNDAY WILL SEE HIGH PRESSURE IN CONTROL THOUGH
THE POSITION OF THE HIGH OVER THE MID ATLANTIC MAY SLIDE MORE MVFR
CIGS OFF THE ATLANTIC INTO OUR EASTERN TAF LOCATIONS.
&&
.EQUIPMENT...
AS OF 400 PM EDT TUESDAY...
THE DEW POINT READING AT KJFZ...RICHLANDS VA AWOS...IS INCORRECT.
AT THIS TIME WE DO NOT KNOW WHEN THIS SENSOR WILL BE REPAIRED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...JH
SHORT TERM...RAB
LONG TERM...AMS/RAB
AVIATION...JH/NF/WP
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
321 AM EDT WED SEP 2 2015
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH THE
END OF THE WEEK. UPPER LEVEL DISTURBANCES TRACKING THROUGH THE
RIDGING WILL RESULT IN WIDELY SCATTERED MAINLY DIURNAL SHOWERS
AND STORMS INTO FRIDAY. A WEAK BACKDOOR COLD FRONT WILL DROP
SOUTH THROUGH THE AREA BY THE END OF WEEK BRINGING SOMEWHAT DRIER
AND COOLER AIR FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 240 AM EDT WEDNESDAY...
OVERALL HOT AND HUMID WEATHER FOR EARLY SEPTEMBER TO PERSIST TODAY AS
SURFACE HIGH PRESSURE REMAINS IN PLACE ACROSS THE MOUNTAINS. HOWEVER
SHORTWAVE ENERGY IN THE FORM OF AN OPENING UPPER LOW ACROSS THE OHIO
VALLEY WILL RIDE SOUTHEAST THROUGH THE 5H RIDGE AND OVER THE NORTHERN
HALF OF THE AREA THIS AFTERNOON. THIS SHOULD RESULT IN BETTER LIFT
ESPCLY ALONG AND JUST SOUTH OF THE INTERSTATE 64 CORRIDOR EARLY ON AND
ACROSS THE EASTERN HALF THROUGH LATE IN THE DAY. LATEST GUIDANCE ALSO
SHOWING BETTER INSTABILITY WITH A LITTLE MORE COOLING ALOFT...BUT STILL
UNCERTAINTY WITH COVERAGE GIVEN OVERALL BROAD SUBSIDENCE IN PLACE UNDER
RATHER WARM 5H TEMPS. CURRENT SPC/RNK WRF SOLUTIONS ALONG WITH THE
LATEST HRRR REMAIN THE MOST WIDESPREAD WITH SHRA/TSRA NORTH HALF AND
ALONG THE BLUE RIDGE. THIS WHILE MOST OTHER SOLUTIONS INCLUDING
ENSEMBLES PRODUCING LESS INCLUDING ONLY WIDELY SCATTERED SHALLOW
CONVECTION MAINLY CONFINED FROM THE VIRGINIA HIGHLANDS EAST TO AROUND
KLYH FOR THE MOST PART. THEREFORE ALIGNED HIGHEST CHANCE POPS ACROSS
THE FAR NORTH WITH A PERIOD OF LOWER CHANCES SOUTH/EAST DURING MID/LATE
AFTERNOON AND ONLY ISOLATED COVERAGE FAR SW. GIVEN WEAK FLOW ALOFT NOT
EXPECTING MUCH OF A SEVERE THREAT BUT COULD SEE A BIT MORE CLUSTERING
OF SLOW MOVING CONVECTION RIGHT NEAR THE CORE OF THE UPPER WAVE LATE.
OTHERWISE LOOKING AT MAINLY PC WITH MID DECK EARLY...THEN MORE CU THIS
AFTERNOON WITH HIGHS AGAIN REACHING THE LOW 90S EAST AND WELL INTO THE
80S ELSEWHERE PENDING TIMING OF CONVECTIVE INITIATION.
IMPULSE PASSES THIS EVENING LEAVING THE REGION IN BETWEEN WAVES AND
UNDER SURFACE HIGH PRESSURE. THIS SHOULD ALLOW MOST CONVECTION TO FADE
BY MIDNIGHT GIVEN LOSS OF HEATING AND SOME OVERNIGHT CLEARING PER WEAK
NW FLOW ALOFT IN THE WAKE OF THE MID LEVEL SYSTEM. THUS KEEPING SOME
LOW END CHANCE POPS GOING MAINLY EAST THIS EVENING BEFORE TRENDING DRY
WITH FOG AGAIN OVERNIGHT. LOWS PERHAPS SLIGHTLY COOLER GIVEN SOME DROP
IN DEWPOINTS AND ESPCLY WHERE ANY COOLING EVENING RAINFALL OCCURS BUT
STILL MOSTLY LOW/MID 60S MOUNTAINS TO UPPER 60S EAST.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
AS OF 345 PM EDT TUESDAY...
THE GFS MOVES THE OHIO SHORT WAVE SLOWER THAN THE NAM/SREF. GIVEN
THE LACK OF A KICKER FOR THIS VORT MAX...THE SLOWER GFS SEEMS MORE
REASONABLE...BUT EVEN ON THIS SLOWER TRACK THE SHORT WAVE WILL STILL
BE SOUTHEAST OF THE FORECAST AREA BY THURSDAY AFTERNOON. WILL EXTEND
THE PROBABILITY OF PRECIPITATION IN THE FORECAST FOR WEDNESDAY
NIGHT. STAYED CLOSER TO MAV GUIDANCE THROUGH THE PERIOD.
BACKDOOR FRONT MOVES SOUTH THROUGH THE NEW ENGLAND AND MID ATLANTIC
COAST. MODELS WERE SHOWING SOME CONVERGENCE IN EASTERN VIRGINIA BUT
STILL QUESTIONABLE HOW MUCH LIFT THIS FEATURE MAY PROVIDE FOR THE
COUNTY WARNING AREA. BEST PROBABILITY OF PRECIPITATION WILL BE IN
THE NORTHEAST COUNTIES OF THE FORECAST AREA...EAST OF THE BLUE
RIDGE. AS THIS FRONT MOVES DOWN THE COAST AND HIGH PRESSURE BUILDS
SOUTH OVER THE APPALACHIANS...WINDS WILL TURN FROM NORTH TO EAST.
THIS EASTERLY COMPONENT OF THE WIND AT THE SURFACE THROUGH LOW
LEVELS MAY ALSO EXPAND THE CLOUD COVER AND PROBABILITY OF
PRECIPITATION ALONG THE BLUE RIDGE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 100 PM EDT TUESDAY...
LOWER 500 MB HEIGHTS REMAINED TRAPPED UNDER THE RIDGE OVER THE
SOUTHEAST UNITED STATES FRIDAY NIGHT THROUGH SUNDAY. SUNDAY NIGHT
INTO TUESDAY...THE CENTER OF THE UPPER RIDGE...DRIFTS SOUTH INTO THE
MID ATLANTIC REGION. HEIGHTS WILL BE CLOSE TO 594DM ACCORDING TO THE
00Z GFS. AT THE SURFACE FRIDAY NIGHT ANY REMNANTS OF THE BACKDOOR
FRONT WASH OUT AND BY SATURDAY THE WEDGE WILL BE FULLY ESTABLISHED
AND THIS FEATURE WILL REMAIN IN PLACE THROUGH SUNDAY. HIGH PRESSURE
WILL COVER THE MID ATLANTIC STATES THROUGH TUESDAY. UNSEASONABLY
WARM TEMPERATURES...WITH 850 MB TEMPERATURES APPROACHING +20...MOVE
INTO THE REGION WITH THE HIGHER HEIGHTS.
A DRIER AIR MASS BEGINS TO APPROACH THE REGION AS THE WEDGE BUILDS
IN ON SATURDAY. SUNDAY AND MONDAY...ECMWF WAS SHOWING MUCH DRIER AIR
ABOVE 850MB. BELOW 850 MB THE DRIER AIR REMAINS EAST AND SOUTH OF
THE FORECAST AREA THROUGH MONDAY.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
AS OF 100 AM EDT WEDNESDAY...
OTHER THAN FOR DEBRIS MID/HIGH CLOUDS...FOG THE MAIN CONCERN
OVERNIGHT WITH POTENTIAL AGAIN GIVEN LESS CLOUDS OF SEEING THE
VALLEYS SUCH AS KLWB/KBCB DROP INTO LIFR/IFR FOR A PERIOD PRIOR TO
DAYBREAK. ALSO SOME FOG POSSIBLE AROUND KLYH-KDAN WHERE BRIEF MVFR
TO IFR POSSIBLE WHILE COVERAGE LOOKS QUITE SPOTTY AT KBLF WHERE
LIMITED TO JUST A VERY BRIEF INCLUSION OF MVFR CONDITIONS AROUND
DAWN.
FOR WEDNESDAY...SHOULD SEE ANY LOW CLOUDS/FOG FADE WITH THE ONSET
OF HEATING ALLOWING FOR VFR CONDITIONS TO QUICKLY RETURN BY MID
MORNING IF NOT SOONER. THEN EXPECT THE UPPER WAVE OVER THE OHIO
VALLEY TO SLOWLY SHIFT SOUTHEAST INTO VIRGINIA. THIS WILL ALLOW
MORE INSTABILITY WITH STEEPER LAPSE RATES AND LIFT. SHOWERS AND
STORMS WILL BE MORE SCATTERED WEDNESDAY AFTERNOON WITH BEST
FORCING ACROSS THE FOOTHILLS/PIEDMONT TO THE NEW RIVER VALLEY. AS
OF NOW WILL KEEP THE GOING VCTS AT KROA/KLYH AND KBCB AFTER
19Z/3PM...BUT THINK COVERAGE WILL BE LESS FURTHER WEST AND
SOUTHEAST...SO ONLY GOING WITH A VCSH AT KLWB-KBLF WHILE KEEPING
MENTION OUT OF KDAN.
OVERALL EXPECT VFR CONDITIONS WEDNESDAY WITH CIGS OF 4-6KFT WITH
TCU AND CB IN THE AFTERNOON.
EXTENDED AVIATION DISCUSSION...
THE FORECAST AREA WILL REMAIN IN A WEAKLY FORCED SYNOPTIC
ENVIRONMENT THROUGH THURSDAY...WITH CHANCES FOR DIURNAL
CONVECTION MAINLY FROM THE BLUE RIDGE WEST...AND SOME MVFR/IFR
FOG/STRATUS DEVELOPMENT AT NIGHT...ESPECIALLY AT KBCB AND KLWB.
FOR FRIDAY INTO SUNDAY WILL SEE HIGH PRESSURE IN CONTROL THOUGH
THE POSITION OF THE HIGH OVER THE MID ATLANTIC MAY SLIDE MORE MVFR
CIGS OFF THE ATLANTIC INTO OUR EASTERN TAF LOCATIONS.
&&
.EQUIPMENT...
AS OF 400 PM EDT TUESDAY...
THE DEW POINT READING AT KJFZ...RICHLANDS VA AWOS...IS INCORRECT.
AT THIS TIME WE DO NOT KNOW WHEN THIS SENSOR WILL BE REPAIRED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...JH
SHORT TERM...AMS
LONG TERM...AMS
AVIATION...JH/NF/WP
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
300 AM CDT WED SEP 2 2015
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 300 AM CDT WED SEP 2 2015
DATA ANALYSIS THIS MORNING FEATURES A MID-LEVEL TROUGH/MCV MAKING
ITS WAY ACROSS SOUTH-CENTRAL MN/CENTRAL IA TOWARD THE UPPER
MISSISSIPPI RIVER VALLEY REGION. THERE HAS BEEN SOME EFFICIENT RAIN-
MAKERS EMBEDDED WITHIN THIS COMPLEX OF CONVECTION GIVEN HUMID/HIGHER
PRECIPITABLE WATER ENVIRONMENT. FEW HOURLY PRECIPITATION REPORTS
COMING IN FROM 3/4 TO JUST OVER AN INCH. OTHERWISE...MUGGY EARLY
MORNING ACROSS THE AREA WITH TEMPERATURES/DEW POINTS IN THE UPPER
60S TO THE MIDDLE 70S.
WILL BE WATCHING THE TROUGH/MCV CONTINUE MOVING ACROSS OUR AREA
TODAY. RAP SHOWING DECENT PUSH OF 850-700MB MOISTURE TRANSPORT
CONTINUING THROUGH 18Z. SO...EXPECTING THIS CONVECTIVE COMPLEX TO
HOLD TOGETHER THROUGH THIS MORNING WITH CHANCES FALLING OFF DURING
THE AFTERNOON FROM WEST TO EAST AS BETTER MOISTURE PUSHES EAST WITH
THE TROUGH. HIGHEST CONCENTRATION OF SHOWERS/STORMS LOOK TO BE NORTH
OF I-90 OR NOSE OF THE BETTER 850-700MB MOISTURE TRANSPORT. ALTHOUGH
SEVERE WEATHER IS NOT ANTICIPATED TO BE WIDESPREAD TODAY GIVEN LOW-
END BULK SHEAR FOR ORGANIZATION...COULD BE SOME SPORADIC HIGHER WIND
GUSTS MIXED IN WITH HEAVIER DOWNPOURS. PLAN ON MUGGY CONDITIONS
OTHERWISE WITH HIGHS IN THE 80S AND DEW POINTS STAYING IN THE UPPER
60S TO LOWER 70S. THIS WILL PUT HEAT INDICES IN THE 90-95 DEGREE
RANGE MAINLY SOUTH OF I-90.
LINGERING SHOWER/THUNDERSTORM CHANCES CONTINUE THROUGH TONIGHT AS
WANING 850-700MB MOISTURE TRANSPORT IMPINGES ON SURFACE TROUGH/WARM
FRONTAL BOUNDARY EAST OF THE MISSISSIPPI RIVER. LOOK FOR MUGGY
OVERNIGHT TEMPERATURES IN THE MIDDLE 60S TO NEAR 70.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 300 AM CDT WED SEP 2 2015
ISOLATED TO SCATTERED SHOWERS/THUNDERSTORMS STILL POSSIBLE ACROSS
CENTRAL WISCONSIN THURSDAY AS THIS AREA WILL BE ALONG THAT
AFOREMENTIONED SURFACE TROUGH/WARM FRONTAL BOUNDARY AND VERY WEAK
850MB MOISTURE TRANSPORT. OTHERWISE...ANOTHER MUGGY DAY ON TAP WITH
HIGHS IN THE 80S AND DEW POINTS HANGING IN THE UPPER 60S/LOWER 70S.
HEAT INDICES ARE EXPECTED TO TOP OFF IN THE 90-95 DEGREE RANGE.
FRIDAY APPEARS DRY BUT RAIN CHANCES INTO THE WEEKEND WILL HANG ON
DISTURBANCES EJECTING OUT OF MONSOONAL FLOW OVER THE SOUTHWEST.
MODELS SEEM TO BE HAVING A DIFFICULT TIME HANDLING THESE FEATURES IN
DETAIL...YIELDING LOW-END SHOWER/THUNDERSTORM CHANCES SATURDAY.
APPEARS LATEST ECMWF/GFS ARE CONVERGING ON SLIGHTLY FASTER TIMING ON
INCOMING MID-LEVEL TROUGH/SURFACE COLD FRONT FROM THE NORTHERN
PLAINS SUNDAY INTO MONDAY. APPEARS HIGHEST SHOWER/THUNDERSTORM
CHANCES WILL BE SUNDAY NIGHT WITH THE COLD FRONT POSSIBLY CLEARING
THE AREA BY AFTERNOON ON LABOR DAY. OTHERWISE...STILL LOOKING HOT
AND MUGGY SATURDAY AND SUNDAY WITH HIGHS WELL INTO THE 80S AND HEAT
INDICES IN THE UPPER 80S TO MIDDLE 90S.
TUESDAY WILL SEE A CHANCE OF SHOWERS AND STORMS ACROSS NORTHEAST IA
INTO FAR SOUTHWEST WI AS THE COLD FRONT STALLS OUT JUST SOUTH OF
THAT AREA. COOLER/DRIER AIR IS ON TAP OTHERWISE WITH HIGHS LOOKING
TO BE IN THE UPPER 60S ACROSS NORTHERN WI...TO THE LOWER/MIDDLE 70S
SOUTH OF I-90.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1055 PM CDT TUE SEP 1 2015
A WEAK WEATHER SYSTEM WILL BE MOVING ACROSS THE AIRFIELDS LATER
TONIGHT AND WEDNESDAY. THERE IS SOME INSTABILITY
PRESENT...CONDITIONAL UPON THE AIR BEING ABLE TO SATURATE. CURRENT
OBSERVATIONS SHOW A -TSRA COMPLEX OVER SWRN MN SHIFTING
NORTHEAST. THERE IS A CHANCE THIS COULD EXPAND SOUTH AND AFFECT
THE TAFS DURING THE MORNING HOURS. HOWEVER...THE AIR APPEARS TO BE
STABLE ENOUGH TO ONLY CAUSE ISOLATED HIGHER BASED ACCAS.
THUS...CONTINUED FORECAST TREND OF NOT INCLUDING TSRA AT THE
AIRFIELDS FOR THE 06Z TAFS.
SOME MVFR FOG MAY BE AROUND LATER TONIGHT AS THE VERY NEAR-SURFACE
AIR MASS IS MORE MOIST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
910 AM EDT WED SEP 2 2015
.UPDATE...
THE REMNANTS OF ERIKA NOW MOVING INLAND OVER THE NORTHEAST GULF
EARLY THIS MORNING WILL CONTINUE TO MOVE SLOWLY NORTHEAST INTO
SOUTHEAST GEORGIA THROUGH THE AFTERNOON WITH THE TRAILING TROUGH
AXIS EXTENDING SOUTHWEST INTO THE GULF GRADUALLY WASHING OUT AS
HIGH PRESSURE SURFACE AND ALOFT RE-BUILDS IN OVER THE REGION. 88D
RETURNS NOW SHOW SOME SHOWERS ASSOCIATED WITH THE TROUGH MOVING
ONSHORE ACROSS LEVY COUNTY WHICH WILL CONTINUE THROUGH THE MORNING
WITH OTHER SHOWERS AND A FEW STORMS NOTED OVER THE COASTAL WATERS
WEST OF SARASOTA...CHARLOTTE...AND LEE COUNTIES...OTHERWISE MAINLY
CLEAR SKIES WERE BEING OBSERVED ACROSS THE FORECAST AREA.
MORNING RAOB DATA SHOWS A MOIST AND UNSTABLE AIRMASS OVER THE
REGION WITH PW`S IN THE 1.9 TO 2.2 INCH RANGE. THIS MOISTURE
COMBINED WITH DAYTIME HEATING SHOULD ALLOW FOR SOME SHOWERS AND
STORMS TO DEVELOP ALONG THE INLAND MOVING SEA BREEZE DURING LATE
MORNING AND INTO THE AFTERNOON. HOWEVER WITH DRY MID LEVEL AIR AND
MILD MID LEVEL TEMPS (-5 TO -6C) IN PLACE OVER THE REGION
ASSOCIATED WITH THE RIDGING ALOFT CONVECTIVE DEVELOPMENT SHOULD
AGAIN BE DELAYED SOME...WITH OVERALL STORM COVERAGE LIKELY TO BE
LIMITED AS WELL WITH ONLY ISOLATED TO LOW SCATTERED RANGE POPS
EXPECTED...WITH HIGHEST POPS OVER INLAND LOCATIONS ALONG THE SEA
BREEZE MERGER...AND TO THE NORTH OF THE I 4 CORRIDOR WHERE DEEPER
MOISTURE RESIDES. THE HRRR AS WELL AS OTHER HI-RES MODELS ARE IN
AGREEMENT WITH THIS SO PLAN TO CUT BACK POPS SLIGHTLY IN A MID
MORNING UPDATE...OTHERWISE NO OTHER GRID OR ZONE CHANGES EXPECTED
AT THIS TIME.
&&
.AVIATION...
OVERALL CONVECTIVE COVERAGE SHOULD BE LIMITED TODAY DUE TO
MILD DRY AIR ALOFT OVER THE REGION...BUT HAVE INCLUDED VCTS AT
ALL SITES JUST THE SAME AFTER 15Z TO ACCOUNT FOR ANY SHRA/TSRA
THAT MAY IMPACT THE TERMINAL SITES...OTHERWISE MAINLY VFR IS
EXPECTED DURING THE NEXT 24 HOURS. LIGHT AND VARIABLE WINDS THIS
MORNING WILL BECOME SOUTHWEST TO WEST AROUND 10 KNOTS AFTER 16Z.
LIGHT AND VARIABLE WINDS WILL RETURN TO ALL SITES AFTER 01Z
TONIGHT.
&&
.MARINE...
THE REMNANTS OF ERIKA OVER THE NORTHEAST GULF EARLY THIS MORNING
WILL CONTINUE TO MOVE TO THE NORTHEAST INTO SOUTHEAST GEORGIA THE
REMAINDER OF TODAY WITH THE TRAILING TROUGH AXIS OVER THE GULF
GRADUALLY WASHING OUT AS HIGH PRESSURE RE-BUILDS IN OVER THE
WATERS. A WEAK PRESSURE PATTERN UNDER THE HIGH WILL SUPPORT
TRANQUIL BOATING CONDITIONS WITH LIGHT WINDS AND SLIGHTS SEAS
WITH AN ONSHORE SEA BREEZE COMPONENT DEVELOPING ALONG THE COAST
BY LATE MORNING. ONGOING FORECAST IS IN GREAT SHAPE WITH NO
CHANGES EXPECTED IN THE NEXT FORECAST ISSUANCE LATER THIS MORNING.
&&
.HYDROLOGY...
HIGH RAINFALL ACCUMULATIONS THIS SUMMER...AND PARTICULARLY DURING
THE LAST 5 TO 6 WEEKS OR SO...HAVE BROUGHT NUMEROUS RIVERS ACROSS
THE AREA INTO MINOR OR MODERATE FLOOD. THERE ARE CURRENTLY SIX
RIVER FORECAST POINTS IN FLOOD ACROSS THE FORECAST AREA...AND TWO
OTHERS ARE IN ACTION STAGE.
RESIDENTS LIVING ALONG RIVERS OR FASTER FLOWING STREAMS SHOULD
CONTINUE TO MONITOR WATER LEVELS AND BE READY TO MOVE TO HIGHER
GROUND SHOULD FLOODING BE OBSERVED...ESPECIALLY WITH THE
POTENTIAL FOR SOME LOCALLY HEAVY RAINFALL THROUGH THE REMAINDER
OF THE WEEK.
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION/MARINE/HYDROLOGY...57/MCMICHAEL
UPPER AIR...74/WYNN
DECISION SUPPORT...05/CARLISLE
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
700 AM CDT WED SEP 2 2015
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 328 AM CDT WED SEP 2 2015
SAME BASIC WEATHER PATTERN REMAINS OVER THE AREA TODAY WITH LARGE
SCALE RIDGING ACROSS THE SOUTHEASTERN 1/3 OF THE CONUS. A SHEAR
AXIS ALOFT STILL STRETCHES FROM EASTERN TEXAS THROUGH ARKANSAS AND
SOUTHEAST MISSOURI INTO THE OHIO VALLEY. A WEAK SHORTWAVE TROF IS
RIDING OVER THE NORTHERN PERIPHERY OF THE RIDGE ACROSS NEBRASKA INTO
IOWA AND IS PRODUCING A BROKEN LINE OF THUNDERSTORMS STRETCHING
ACROSS CENTRAL IOWA INTO NORTHWEST MISSOURI. CURRENT THINKING IS
THAT THESE STORMS WON`T MAKE IT INTO OUR CWFA THIS MORNING BUT
SHOULD WEAKEN AND DISSIPATE AFTER SUNRISE. ANOTHER WARM HUMID DAY
IS EXPECTED WITH HIGHS SIMILAR TO TUESDAY`S...PERHAPS A DEGREE OR
TWO WARMER. SIGNALS FOR AFTERNOON CONVECTION ARE WEAKER IN THE
GUIDANCE THAN THEY WERE FOR YESTERDAY, SO HAVE A DRY FORECAST GOING
THIS MORNING. THAT BEING SAID, I WOULDN`T BE SURPRISED AT ALL IF
SOME ISOLATED THUNDERSTORMS DEVELOPED THIS AFTERNOON.
CARNEY
.LONG TERM: (TONIGHT THROUGH TUESDAY)
ISSUED AT 346 AM CDT WED SEP 2 2015
UPPER LEVEL RIDGE CONTINUES TO CONTROL OUR WEATHER THROUGH THE END
OF THE WEEK INTO THE WEEKEND. THEREFORE IT LOOKS LIKE A PRETTY
STAGNANT WEATHER PATTERN WHICH SHOULD KEEP TEMPERATURES ABOVE NORMAL
WITH LITTLE OR NO CHANCE FOR PRECIP AT LEAST THROUGH SUNDAY OR
MONDAY. MEDIUM RANGE GUIDANCE TRIES TO BEGIN SHIFTING THE PATTERN
MONDAY INTO TUESDAY BY BRINGING THE LONGWAVE TROF OVER THE WEST
COAST ACROSS THE ROCKIES AND UP THROUGH THE NORTHERN PLAINS. THIS
SHOULD AT LEAST PARTIALLY BREAK DOWN THE RIDGE OVER OUR AREA
BRINGING US A CHANCE OF RAIN AND PERHAPS SOME COOLER TEMPERATURES BY
TUESDAY.
CARNEY
&&
.AVIATION: (FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 647 AM CDT WED SEP 2 2015
SHORTWAVE RIDING TOP OF RIDGE CONTINUES TO FUEL BAND OF CONVECTION
FROM CENTRAL IA INTO NW MO, HOWEVER HRRR DATA THROUGHOUT THE
OVERNIGHT HOURS HAS MAINTAINED THE THE GENERAL IDEA THAT THIS
ACTIVITY WILL WEAKEN AND DISSIPATE BEFORE REACHING KCOU OR KUIN.
HIGH CLOUDINESS (AOA 10KFT) ASSOCIATED WITH THIS CONVECTION WILL
OVERSPREAD AREA THIS MORNING, FOLLOWED BY A BIT OF DIURNAL, HI
BASED CU FORMING ONCE AGAIN AROUND MIDDAY.
SPECIFICS FOR KSTL: VFR CONDITIONS ARE EXPECTED, WITH CI WORKING
ACROSS THE AREA THIS MORNING, AND DIURNAL CU WITH BASES AOA 5KFT
THIS AFTERNOON.
TRUETT
&&
.PRELIMINARY POINT TEMPS/POPS:
SAINT LOUIS 94 74 94 75 / 5 5 10 5
QUINCY 92 69 92 70 / 10 5 10 5
COLUMBIA 92 69 93 70 / 10 5 5 0
JEFFERSON CITY 92 69 93 70 / 5 5 5 5
SALEM 92 70 91 70 / 10 5 10 5
FARMINGTON 92 68 92 68 / 10 5 5 0
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1015 AM EDT WED SEP 2 2015
.SYNOPSIS...A DISTURBANCE WILL DROP SOUTHEAST THROUGH THE AREA
TONIGHT THROUGH EARLY THURSDAY...BUT OTHERWISE DEEP HIGH PRESSURE
WILL HOLD OVER THE REGION THROUGH FRIDAY. A COLD FRONT WILL MOVE
SOUTHWARD THROUGH THE AREA LATE FRIDAY INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM WEDNESDAY...
PLENTY OF SUNSHINE THIS MORNING ALTHOUGH IT`S BEING FILTERED
SOMEWHAT BY AREAS OF THIN MID-HIGH CLOUDS BLOWN OFF OF CONVECTION
OVER AND SOUTH OF THE LOWER MISS VALLEY. THE POTENT MID LEVEL WAVE
WE`VE BEEN WATCHING FOR THE LAST FEW DAYS OVER CENTRAL INDIANA IS
NOTED THIS MORNING OVER SE OHIO IS ON TRACK TO DROP SE INTO AND
THROUGH THE AREA LATER TODAY THROUGH TONIGHT. THE TIMING INDICATED
BY THE SPC SSEO / NSSL WRF / 3KM NAM CONUS NEST / NCAR ENSEMBLE
NEIGHBORHOOD PROBABILITIES ARE FAIRLY CLOSE TO THE EXISTING
FORECAST... BRINGING GOOD COVERAGE INTO THE EXTREME NORTHERN CWA
AFTER 19Z OR 20Z... THEN DROPPING TO THE SSE PEAKING IN COVERAGE
AROUND 00Z... THEN MOVING INTO THE SRN/SE CWA WHILE CONTINUING TO
WEAKEN BEFORE DISSIPATING AROUND OR SOON AFTER 06Z. HAVE MADE MINOR
TIMING DIFFERENCES AND HAVE INCREASED INITIAL COVERAGE IN THE 21Z-
03Z TIME FRAME ACROSS THE NORTH. HAVE ALSO ADDED IN LOW CHANCE POPS
IN THE YADKIN VALLEY LATE THIS AFTERNOON AS THE HRRR AND NSSL WRF
DEPICT MOUNTAIN CONVECTION DRIFTING INTO THE SW AND EXTREME WRN CWA
LATE. MODELS CONTINUE TO VARY ON INSTABILITY POTENTIAL WITH THE NAM
(AND IT`S SLIGHTLY HIGHER SURFACE DEWPOINTS) SHOWING MUCAPE VALUES
NEARLY A MAGNITUDE GREATER THAN THE GFS. DEEP LAYER SHEAR REMAINS
MARGINAL AT JUST 20-25 KTS... SO EITHER WAY DON`T EXPECT A GREAT
SEVERE THREAT... ALTHOUGH A FEW STORMS COULD GET STRONG GIVEN THE
DYNAMIC CONTRIBUTION FROM DPVA. THICKNESSES AND HRRR/GRIDDED LAMP/
LOCAL WRF GUIDANCE SUPPORT HIGHS OF 90-94. -GIH
ISOLATED-SCATTERED CONVECTION WILL SLOWLY WANE TONIGHT AS THE LOW
LEVEL AIR MASS UNDERGOES ITS NORMAL NOCTURNAL STABILIZATION. BULK OF
CONVECTION WILL DISSIPATE PRIOR TO 06Z THOUGH POTENTIAL FOR A FEW
SHOWERS TO PERSIST IN THE COASTAL PLAIN UP TO SUNRISE. MIN TEMPS 67-
73. -WSS
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 258 AM WEDNESDAY...
WEAK SUBSIDENCE BEHIND THE DEPARTING DISTURBANCE SHOULD INHIBIT
CONVECTIVE REDEVELOPMENT THURSDAY MORNING. HEATING OF THE AIR MASS
OVER CENTRAL NC SHOULD TRIGGER ISOLATED CONVECTION ABOUT ANYWHERE IN
THE MID-LATE AFTERNOON HOURS. ANOTHER UPPER DISTURBANCE...THOUGH
WEAKER THAN THE SYSTEM EXPECTED TONIGHT...WILL APPROACH FROM THE NW
LATE IN THE DAY AND CROSS CENTRAL NC THURSDAY NIGHT. THIS SYSTEM MAY
PROVIDE ENOUGH LIFT TO INITIATE/SUSTAIN A SHOWER OR TWO BUT FEEL
THAT MOST PLACES WILL REMAIN DRY THURSDAY NIGHT. MAX TEMPS THURSDAY
SHOULD BE COMPARABLE TO DAY...90-95 DEGREES...WITH MIN TEMPS THU
NIGHT 67-72.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 305 AM WEDNESDAY...
FRIDAY THROUGH SATURDAY NIGHT: A BACKDOOR COLD FRONT WILL SINK
SOUTHWARD THROUGH THE AREA ON FRIDAY INTO FRIDAY EVENING AS ANOTHER
WEAK IMPULSE IN THE NORTH-NORTHWEST TO NORTHWESTERLY MID LEVEL FLOW
MOVES ACROSS THE AREA. THIS WILL TRIGGER AT LEAST ISOLATED TO
SCATTERED SHOWERS AND SOME STORMS FRIDAY AFTERNOON INTO THE EVENING.
OVERALL DEEP FLOW CONTINUES TO BE QUITE WEAK. GIVEN THIS AND RATHER
WEAK TO MODEST INSTABILITY EXPECT LITTLE IN THE WAY OF A SEVERE
THREAT... WITH THE ONLY LIMITED THREAT FROM LOCALIZED.... MAINLY
URBAN... FLOODING AS PW/S ARE EXPECTED TO BE AROUND 1.75" OR SO ON
FRIDAY. HIGH TEMPS FRIDAY IN ADVANCE OF THE FRONT ARE EXPECTED TO
REACH INTO THE UPPER 80S TO LOWER 90S. SURFACE HIGH PRESSURE WILL
BUILD INTO THE AREA FROM THE NORTH/NORTHEAST ON FRIDAY NIGHT INTO
SATURDAY. HOWEVER... WE WILL LIKELY SEE SOME LINGERING PRECIP
CHANCES AS A WEAK MID LEVEL LOW DEVELOPS JUST TO THE SOUTH OF THE
AREA. THUS... EXPECT LOW POPS (SLIGHT CHANCE) IN THE NORTHEAST...
WITH THE HIGHEST POPS (CHANCE) IN THE SOUTHWEST. GIVEN NORTHEAST TO
EASTERLY LOW LEVEL FLOW... WE WILL LIKELY START THE DAY WITH A GOOD
BIT OF CLOUD COVER/LOW STRATUS. GIVEN THE COOLER AIR MASS FROM THE
NORTH AND EXPECTED CLOUD COVER... WILL GO WITH HIGHS ON SATURDAY IN
THE LOWER TO MID 80S (AND THIS MAY STILL BE TOO WARM IN SPOTS). LOWS
SATURDAY MORNING ARE EXPECTED TO BE IN THE UPPER 60S AND IN THE MID
TO UPPER 60S SUNDAY MORNING.
SUNDAY THROUGH TUESDAY: THE WEAK MID LEVEL LOW WILL CONTINUE TO
LINGER ACROSS THE SOUTHEAST U.S. DURING THIS TIMEFRAME WHILE SLOWLY
SINKING SOUTHWESTWARD... YET STILL EXTENDING INTO OUR AREA... ALONG
WITH AN INVERTED SURFACE TROUGH NEAR THE COAST TO EASTERN PORTIONS
OF OUR AREA. THIS WILL GENERALLY RESULT IN THE BEST CHANCES FOR
PRECIP TO THE SOUTH OF OUR AREA... BUT WE COULD SEE SOME ISOLATED TO
SCATTERED SHOWERS AND STORMS EACH DAY (MAINLY DIURNAL IN NATURE) AND
GENERALLY ACROSS EASTERN AND SOUTHEASTERN PORTIONS OF CENTRAL NC.
HIGHS WILL REMAIN IN THE 80S... COOLEST ON SUNDAY... WITH LOWS IN
THE 60S.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 705 AM WEDNESDAY...
THERE IS A HIGH LIKELIHOOD THAT VFR CONDITIONS WILL CONTINUE THROUGH
TONIGHT. THE EXCEPTION WILL BE ISOLATED-SCATTERED CONVECTION WHICH
WILL DEVELOP OR MOVE INTO CENTRAL NC FROM THE NORTH AFTER 18Z. THE
CONVECTION WILL BE SPARKED BY A SEWD MOVING UPPER LEVEL DISTURBANCE
WHICH WILL CROSS OUR REGION EARLY THIS EVENING. CONFIDENCE THAT
CONVECTION WILL OCCUR AT ANY ONE TAF SITES IS FAIRLY LOW BUT WILL
MENTION VICINITY SHOWER IN THE TRIAD TERMINALS THIS AFTERNOON...AND
NEAR KRDU AND KRWI EARLY THIS EVENING.
THE EXTENDED OUTLOOK SUGGEST MAINLY VFR CONDITIONS THOUGH COULD SEE
A BRIEF PERIOD OF EARLY MORNING FOG/STRATUS THURSDAY MORNING AND
FRIDAY MORNING. ALSO...COULD SEE SCATTERED CONVECTION DEVELOP FRIDAY
AFTERNOON INTO FRIDAY NIGHT AHEAD OF A SURFACE BOUNDARY WHICH
PROGRESS SOUTHWARD ACROSS THE AREA. THIS FEATURE MAY CAUSE UNSETTLED
WEATHER TO LINGER INTO SATURDAY WITH IMPROVING AVIATION CONDITIONS
EXPECTED BY SUNDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/WSS
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...WSS
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
620 AM CDT WED SEP 2 2015
.DISCUSSION...UPDATED FOR THE 12Z AVIATION DISCUSSION.
&&
.AVIATION...ISOLATED CONVECTION ONGOING BETWEEN CRP-VCT AS OF
WRITING. WILL EXPECT DEVELOPMENT FARTHER INLAND TO ALI WITH
ADDITIONAL HEATING AS THE DAY PROGRESSES. CIGS DEVELOPING...YET
CONTINUE TO REPORT VFR AT CRP-ALI-VCT...ALTHOUGH BRIEF PERIODS OF
MVFR WILL REMAIN POSSIBLE THROUGH MID MORNING. SATELLITE IMAGERY
IS SHOWING LARGER COVERAGE OF LOW CIG DEVELOPMENT ACROSS THE RIO
GRANDE PLAINS AND WESTERN BRUSH COUNTRY TO AFFECT LRD. WILL EXPECT
MVFR AT LRD TO CONTINUE THROUGH AT LEAST 16Z BEFORE LIFTING TO
VFR. HAVE RAIN CHANCES TAPERING OFF THROUGH THE LATE AFTERNOON
WITH THE LOSS OF HEATING. DID LOWER CLOUDS LATE IN THE
PERIOD...BUT FOR NOW MAINTAINED VFR ALTHOUGH TEMPO MVFR AFTER 09Z
MAY BE ADDED.
&&
.PREV DISCUSSION... /ISSUED 414 AM CDT WED SEP 2 2015/
SHORT TERM (TODAY THROUGH THURSDAY)...THE MID LEVEL LOW/TROUGH IS
STILL HANGING AROUND THE TEXAS COAST PER THE WATER VAPOR IMAGERY.
THIS COMBINED WITH PWATS OF NEAR 2 INCHES DRAPED ALONG THE EASTERN
CWA WILL CONTINUE ISOLATED TO SCATTERED SHOWER AND THUNDERSTORM
DEVELOPMENT...FOCUSING ALONG THE COASTAL CONVERGENCE DURING THE
MORNING HOURS /ESPECIALLY TOWARD THE NORTHERN COASTAL BEND/...THEN
SHIFTING FARTHER INLAND WITH THE SEA BREEZE. HRRR AND TEXAS TECH
MODELS CONTINUE COASTAL ACTIVITY THROUGH THE EARLY AFTERNOON
/WITH TX TECH MODEL BEING THE MORE AGGRESSIVE OF THE TWO/ BEFORE
SHIFTING FARTHER INLAND...SO HAVE EXTENDED CHANCE POPS FARTHER
EAST IN THE AFTERNOON HOURS. ACTIVITY WILL WANE WITH THE LOSS OF
HEATING...BUT A SIMILAR SITUATION IS EXPECTED TO REDEVELOP LATER
TONIGHT THROUGH THURSDAY. TEMPERATURES WILL HEAVILY RELY ON ACTUAL
RAINFALL AND CLOUD COVERAGE...HOWEVER MAINTAINED RELATIVELY
PERSISTENT WITH TEMPS ACROSS THE EASTERN ZONES...BUT DID RAISE
TEMPS OUT WEST BY A FEW DEGREES.
LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...CONVECTIVE CHANCES
/ALBEIT RATHER LOW/ WILL CONTINUE TO BE PRIMARY FORECAST CHALLENGE
FOR THE LONG TERM PERIOD. UPPER LEVEL DYNAMICAL CONVECTIVE SUPPORT
WILL DIMINISH BY LATE THIS WEEK WITH PRIMARY CONVECTIVE CHANCES
BECOMING DIURNALLY SUPPORTED /COMMON PATTERN FOR THIS TIME OF YEAR/.
SUFFICIENT DEEP LAYER MOISTURE /PWATS GENERALLY 1.75 TO 2 INCHES/ IS
PROG TO PERSIST THROUGH MOST OF THE LONG TERM PERIOD. ISOLATED TO
SCATTERED CONVECTION IS PROG TO DEVELOP ACROSS MARINE AREAS AND THE
COASTAL COUNTIES THURSDAY NIGHT AS A NOCTURNALLY DRIVEN UNSTABLE
AIRMASS DEVELOPS ALONG THE COAST AND JUST OFFSHORE WITH SBCAPES PROG
TO BE AROUND 2500 J/KG. CONVECTIVE ACTIVITY /SCATTERED AT BEST/
SHOULD DEVELOP FURTHER IN AREAL COVERAGE ACROSS THE COASTAL PLAINS
AND NORTHERN COASTAL BEND BY MID MORNING FRIDAY WITH ACTIVITY THEN
SHIFTING INLAND DURING THE AFTERNOON. CONVECTIVE COVERAGE ON
SATURDAY IS EXPECTED TO BE MUCH MORE ISOLATED AS MID LEVEL TEMPS ARE
PROG TO INCREASE WITH STRENGTHENING RIDGING...THUS CAPPING THE
ATMOSPHERE TO AN EXTENT. EVEN WARMER MID LEVEL TEMPS ON SUNDAY
SHOULD KEEP MOST AREAS DRY. MID LEVEL RIDGE CENTER IS THEN PROG TO
SHIFT WESTWARD SLOWLY EARLY NEXT WEEK...ALLOWING FOR A RETURN OF
ISOLATED TO SCATTERED CONVECTION /AGAIN BEST CHANCES ALONG THE COAST
AND OFFSHORE AT NIGHT/MORNING AND INLAND DURING THE DAY/. ASIDE FROM
CONVECTION...ANOTHER ITEM OF CONCERN FOR THE LONG TERM PERIOD WILL
BE HEAT INDICES. A SURGE OF HIGHER NEAR SURFACE MOISTURE IS PROG TO
OCCUR FOR OVER THE UPCOMING HOLIDAY WEEKEND. AFTERNOON HEAT INDICES
OVER THE LABOR DAY WEEKEND ARE CURRENTLY EXPECTED TO RANGE FROM 105
TO 110 DEGREES WITH HIGH TEMPS IN THE MID 90S TO AROUND 100...AND
AROUND 90 AT THE BEACH. THOSE WITH OUTDOOR ACTIVITIES THIS WEEKEND
ARE URGED TO DRINK PLENTY OF WATER AND TO SEEK SHADE WHEN POSSIBLE.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 90 75 90 76 93 / 30 20 30 20 30
VICTORIA 89 73 89 74 93 / 30 30 40 20 30
LAREDO 98 76 98 78 100 / 10 10 20 10 10
ALICE 92 74 93 73 97 / 30 10 40 10 30
ROCKPORT 85 77 87 79 91 / 40 30 40 30 30
COTULLA 97 74 97 77 99 / 10 10 20 10 10
KINGSVILLE 90 75 91 76 96 / 30 20 40 10 20
NAVY CORPUS 85 77 87 79 91 / 40 30 40 20 30
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
CB/85...AVIATION
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
940 AM EDT WED SEP 2 2015
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH THE
END OF THE WEEK. UPPER LEVEL DISTURBANCES TRACKING THROUGH THE
RIDGING WILL RESULT IN WIDELY SCATTERED MAINLY DIURNAL SHOWERS
AND STORMS INTO FRIDAY. A WEAK BACKDOOR COLD FRONT WILL DROP
SOUTH THROUGH THE AREA BY THE END OF WEEK BRINGING SOMEWHAT DRIER
AND COOLER AIR FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM EDT WEDNESDAY...
EARLY MORNING FOG HAS DISSIPATED IN ALL BUT PARTS OF THE
GREENBRIER AND NEW RIVER VALLEY REGIONS. HOWEVER...BY 1100 AM...AT
VAST MAJORITY...IF NOT ALL...OF THIS FOG WILL HAVE DISSIPATED AS
WELL. PRECIPITATION COVERAGE ACROSS THE REGION CURRENTLY IS ZERO.
THERE WERE A FEW ISOLATED SHOWERS OVER BUCKINGHAM COUNTY AROUND
THE TOP THE HOUR..BUT THESE HAVE SINCE FADED. LATEST MESOSCALE
MODELS PAINTS VERY LITTLE IF ANY PRECIPITATION ACROSS THE
NORTHERN PARTS OF THE AREA THROUGH 17Z/1PM...AND THEN START
RAMPING UP THE COVERAGE AFTER THAT TIME. HAVE TWEAKED THE
PROBABILITY OF PRECIPITATION GRIDS AND THE WEATHER GRIDS TO BETTER
REFLECT THIS TREND. NO OTHER NOTABLE CHANGES AT THIS TIME.
AS OF 240 AM EDT WEDNESDAY...
OVERALL HOT AND HUMID WEATHER FOR EARLY SEPTEMBER TO PERSIST TODAY AS
SURFACE HIGH PRESSURE REMAINS IN PLACE ACROSS THE MOUNTAINS. HOWEVER
SHORTWAVE ENERGY IN THE FORM OF AN OPENING UPPER LOW ACROSS THE OHIO
VALLEY WILL RIDE SOUTHEAST THROUGH THE 5H RIDGE AND OVER THE NORTHERN
HALF OF THE AREA THIS AFTERNOON. THIS SHOULD RESULT IN BETTER LIFT
ESPCLY ALONG AND JUST SOUTH OF THE INTERSTATE 64 CORRIDOR EARLY ON AND
ACROSS THE EASTERN HALF THROUGH LATE IN THE DAY. LATEST GUIDANCE ALSO
SHOWING BETTER INSTABILITY WITH A LITTLE MORE COOLING ALOFT...BUT STILL
UNCERTAINTY WITH COVERAGE GIVEN OVERALL BROAD SUBSIDENCE IN PLACE UNDER
RATHER WARM 5H TEMPS. CURRENT SPC/RNK WRF SOLUTIONS ALONG WITH THE
LATEST HRRR REMAIN THE MOST WIDESPREAD WITH SHRA/TSRA NORTH HALF AND
ALONG THE BLUE RIDGE. THIS WHILE MOST OTHER SOLUTIONS INCLUDING
ENSEMBLES PRODUCING LESS INCLUDING ONLY WIDELY SCATTERED SHALLOW
CONVECTION MAINLY CONFINED FROM THE VIRGINIA HIGHLANDS EAST TO AROUND
KLYH FOR THE MOST PART. THEREFORE ALIGNED HIGHEST CHANCE POPS ACROSS
THE FAR NORTH WITH A PERIOD OF LOWER CHANCES SOUTH/EAST DURING MID/LATE
AFTERNOON AND ONLY ISOLATED COVERAGE FAR SW. GIVEN WEAK FLOW ALOFT NOT
EXPECTING MUCH OF A SEVERE THREAT BUT COULD SEE A BIT MORE CLUSTERING
OF SLOW MOVING CONVECTION RIGHT NEAR THE CORE OF THE UPPER WAVE LATE.
OTHERWISE LOOKING AT MAINLY PC WITH MID DECK EARLY...THEN MORE CU THIS
AFTERNOON WITH HIGHS AGAIN REACHING THE LOW 90S EAST AND WELL INTO THE
80S ELSEWHERE PENDING TIMING OF CONVECTIVE INITIATION.
IMPULSE PASSES THIS EVENING LEAVING THE REGION IN BETWEEN WAVES AND
UNDER SURFACE HIGH PRESSURE. THIS SHOULD ALLOW MOST CONVECTION TO FADE
BY MIDNIGHT GIVEN LOSS OF HEATING AND SOME OVERNIGHT CLEARING PER WEAK
NW FLOW ALOFT IN THE WAKE OF THE MID LEVEL SYSTEM. THUS KEEPING SOME
LOW END CHANCE POPS GOING MAINLY EAST THIS EVENING BEFORE TRENDING DRY
WITH FOG AGAIN OVERNIGHT. LOWS PERHAPS SLIGHTLY COOLER GIVEN SOME DROP
IN DEWPOINTS AND ESPCLY WHERE ANY COOLING EVENING RAINFALL OCCURS BUT
STILL MOSTLY LOW/MID 60S MOUNTAINS TO UPPER 60S EAST.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 415 AM EDT WEDNESDAY...
WEAK UPPER-LEVEL SHORT WAVE WILL BE DISSIPATING ACROSS NORTH
CAROLINA DRIFTING SLOWLY INTO THE SOUTHEAST STATES WHERE IT
APPEARS IT IS DESTINED TO BECOME A WEAK CUTOFF THAT WILL
RETROGRADE/LINGER ACROSS THE SOUTHEAST/MID-SOUTH INTO NEXT WEEK AS
A LARGE HIGH AMPLITUDE UPPER RIDGE CONTINUES TO BUILD FROM THE
SOUTH CENTRAL/CENTRAL U.S. INTO SOUTHEAST CANADA AND THE NORTHEAST
U.S. OVER THE TOP OF THE WEAK CUTOFF LOW. UPPER SUPPORT WILL BE
MINIMAL AT BEST WITH BEST DYNAMICS...WHAT THEY ARE...HAVING
DRIFTED SOUTH OF THE AREA. ANY CONVECTION WILL LARGELY BE THE
RESULT OF DIFFERENTIAL HEATING AND FOCUSED PRIMARILY ACROSS THE
WESTERN MOUNTAINS. REALLY CANNOT SUPPORT MUCH MORE THAN 30 POPS AT
BEST.
BY FRIDAY...A LARGE SURFACE HIGH DEVELOPING ACROSS THE NORTHEAST
U.S. UNDERNEATH THE MAMMOTH UPPER RIDGE WILL BEGIN TO PUSH A
BACKDOOR FRONT FROM THE MID-ATLANTIC SOUTHWESTWARD. UPPER DYNAMICS
ARE VERY WEAK...BUT A MARKED DEWPOINT GRADIENT WILL EXIST ALONG
THE SOUTHWESTWARD ADVANCING BOUNDARY AS VERY DRY AIR ADVECTS
SOUTHWEST INTO NORTHERN VA. THIS SHOULD BE SUFFICIENT TO SUPPORT
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS...WITH THE BEST
COVERAGE SHIFTING SOUTHWEST TOWARD EVENING. INSTABILITY IS QUITE
NOTABLE ACROSS THE REGION IN ADVANCE OF THIS BACKDOOR FRONT...SO
EVEN WITH WEAK DYNAMICS...WITH THE NOTED INSTABILITY AND PWATS IN
THE 1.5 TO 1.7 INCH RANGE...30-40 PERCENT POPS SEEMS REASONABLE.
FOR SATURDAY...THE BACKDOOR FRONT CONTINUES TO DRIFT SOUTHWEST AND
SHOULD BE LOCATED FROM CENTRAL WV THROUGH SOUTHWEST VA...NEAR THE
I-77 CORRIDOR...INTO CENTRAL NC. VERY DRY AIR IS NOTED ADVECTING
INTO THE REGION FROM THE NORTHEAST WITH DEWPOINTS DROPPING INTO
THE 50S AND PWATS FALLING TO NEAR 0.50 INCH ACROSS THE NORTHEAST
PART OF THE CWA. ANY CONVECTION SATURDAY SHOULD BE LIMITED TO THE
I-77 CORRIDOR AND POINTS WESTWARD...PRIMARILY DURING THE
AFTERNOON/EVENING.
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL THURSDAY AND FRIDAY
AHEAD OF THE BACKDOOR FRONT...WITH MAX TEMPS WELL INTO THE
80S...NEAR 90 ACROSS THE PIEDMONT. MIN TEMPS WILL HOLD MOSTLY IN
THE 60S TO EVEN NEAR 70 ACROSS THE PIEDMONT. THESE READINGS ARE
AROUND 5 AND 10 DEGREES ABOVE NORMAL...RESPECTIVELY. MOS GUIDANCE
HAS BEEN TRENDING TOO MUCH TOWARD CLIMATOLOGY...SO NEEDED TO NUDGE
UP MOST AREAS FROM 2-3 DEGREES TO BETTER MATCH WHAT HAS BEEN
OCCURRING RECENTLY.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 445 AM EDT WEDNESDAY...
THE FOCUS THROUGH THE PERIOD WILL BE ON THE AFOREMENTIONED WEAK
AND INCREASING BROAD UPPER LOW ANCHORED ACROSS THE SOUTHEAST/MID-
SOUTH PART OF THE U.S. OUR CWA WILL BE STUCK IN THE TRANSITION
ZONE BETWEEN THIS INCREASINGLY MOIST/UNSTABLE AIR MASS TO THE
SOUTH AND THE PERSISTING UPPER RIDGE AND ASSOCIATED
SUBSIDENCE/VERY DRY AND WARM AIR MASS ACROSS THE MID-ATLANTIC
REGION. SHOWER/THUNDERSTORM CHANCES WILL GRADUALLY CREEP NORTHWARD
THROUGH THE PERIOD...BUT LIKELY REMAIN CONFINED TO AREAS WEST OF
I-77 SUNDAY...THEN CREEP FURTHER NORTH TOWARD THE U.S. 460
CORRIDOR BY MONDAY AND MUCH OF THE CWA BY TUESDAY. THE BEST
CHANCES THROUGHOUT THE PERIOD WILL REMAIN ACROSS THE WESTERN NC
MOUNTAINS. THE MODELS HAVE CONTINUALLY DELAYED THE ARRIVAL OF A
FRONT TOWARD THE MID PART OF NEXT WEEK...AND WITH THE UPPER RIDGE
SANDWICHED IN BETWEEN THE LOW PRESSURE AREA TO THE SOUTH AND THE
STRONGER WESTERLIES ALONG THE CANADIAN BORDER...IT MAY BE SOME
TIME BEFORE IT ACTUALLY REACHES OUR AREA. HENCE...SUMMER APPEARS
DESTINED TO HANG ON MUCH OF NEXT WEEK.
MAX TEMPS SHOULD BE NEAR NORMAL AT THE BEGINNING OF THE
PERIOD...BUT PERHAPS STILL SLIGHTLY ABOVE NORMAL WEST OF I-77. MIN
TEMPS WILL REMAIN NEAR NORMAL TO SLIGHTLY ABOVE NORMAL FAR
SOUTHWEST. MAX AND MIN TEMPS WILL CREEP TO SLIGHTLY ABOVE NORMAL
LEVELS AGAIN AS WE MOVE INTO EARLY NEXT WEEK.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
AS OF 640 AM EDT WEDNESDAY...
FOG AND STRATUS REMAIN SPOTTY ACROSS THE REGION EARLY THIS MORNING
WITH THE TYPICAL VALLEY LOCATIONS SUCH AS KLWB/KBCB SEEING IFR OR
WORSE ATTM. EXPECT COULD SEE A BRIEF REDUCTION IN VSBY AS WELL
AROUND KLYH/KDAN AS WELL DURING THE NEXT HOUR OR TWO BEFORE
HEATING HELPS DISSIPATE ANY RESIDUAL LOW LEVEL MOISTURE. OTHERWISE
WAVES OF MID/HIGH CLOUDS AHEAD OF THE UPPER SYSTEM TO THE NW THE
MAIN ASPECT ONCE ANY LOW CLOUDS BURN OFF WITH VFR EXPECTED AT ALL
LOCATIONS FROM MID MORNING ONWARD.
UPPER WAVE OVER THE OHIO VALLEY WILL SHIFT SLOWLY SOUTHEAST INTO
VIRGINIA THIS AFTERNOON WHILE SLOWLY WEAKENING. THIS WILL ALLOW
MORE INSTABILITY WITH STEEPER LAPSE RATES AND LIFT. SHOWERS AND
STORMS WILL BE MORE SCATTERED THIS AFTERNOON WITH BEST FORCING
ACROSS THE NORTHERN FOOTHILLS/PIEDMONT TO THE NEW RIVER VALLEY.
AS OF NOW WILL KEEP THE GOING VCTS AT KROA/KLYH AND KBCB AFTER
19-20ZZ/3-4PM...BUT THINK COVERAGE WILL BE LESS FURTHER WEST AND
OVER THE SOUTHEAST...SO ONLY GOING WITH A VCSH AT KLWB-KBLF WHILE
KEEPING MENTION OUT OF KDAN FOR NOW. OVERALL EXPECT VFR
CONDITIONS OUTSIDE ANY CONVECTION INTO THIS EVENING WITH CIGS OF
4-6KFT WITH TCU AND CB IN THE AFTERNOON.
EXTENDED AVIATION DISCUSSION...
THE FORECAST AREA WILL REMAIN IN A WEAKLY FORCED SYNOPTIC
ENVIRONMENT THROUGH THURSDAY...WITH CHANCES FOR DIURNAL
CONVECTION MAINLY FROM THE BLUE RIDGE WEST...AND SOME MVFR/IFR
FOG/STRATUS DEVELOPMENT AT NIGHT...ESPECIALLY AT KBCB AND KLWB. A
WEAK BACKDOOR COOL FRONT MAY ENHANCE THE CHANCES FOR SHOWERS AND
STORMS LATER FRIDAY BEFORE DRIER AIR ARRIVES FRIDAY NIGHT.
FOR SATURDAY INTO SUNDAY WILL SEE HIGH PRESSURE IN CONTROL THOUGH
THE POSITION OF THE HIGH OVER THE MID ATLANTIC MAY SLIDE MORE MVFR
CIGS OFF THE ATLANTIC INTO OUR EASTERN TAF LOCATIONS AT LEAST TO
START THE WEEKEND.
&&
.EQUIPMENT...
AS OF 400 PM EDT TUESDAY...
THE DEW POINT READING AT KJFZ...RICHLANDS VA AWOS...IS INCORRECT.
AT THIS TIME WE DO NOT KNOW WHEN THIS SENSOR WILL BE REPAIRED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...DS/JH
SHORT TERM...RAB
LONG TERM...AMS/RAB
AVIATION...JH/NF/WP
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
654 AM EDT WED SEP 2 2015
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH THE
END OF THE WEEK. UPPER LEVEL DISTURBANCES TRACKING THROUGH THE
RIDGING WILL RESULT IN WIDELY SCATTERED MAINLY DIURNAL SHOWERS
AND STORMS INTO FRIDAY. A WEAK BACKDOOR COLD FRONT WILL DROP
SOUTH THROUGH THE AREA BY THE END OF WEEK BRINGING SOMEWHAT DRIER
AND COOLER AIR FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 240 AM EDT WEDNESDAY...
OVERALL HOT AND HUMID WEATHER FOR EARLY SEPTEMBER TO PERSIST TODAY AS
SURFACE HIGH PRESSURE REMAINS IN PLACE ACROSS THE MOUNTAINS. HOWEVER
SHORTWAVE ENERGY IN THE FORM OF AN OPENING UPPER LOW ACROSS THE OHIO
VALLEY WILL RIDE SOUTHEAST THROUGH THE 5H RIDGE AND OVER THE NORTHERN
HALF OF THE AREA THIS AFTERNOON. THIS SHOULD RESULT IN BETTER LIFT
ESPCLY ALONG AND JUST SOUTH OF THE INTERSTATE 64 CORRIDOR EARLY ON AND
ACROSS THE EASTERN HALF THROUGH LATE IN THE DAY. LATEST GUIDANCE ALSO
SHOWING BETTER INSTABILITY WITH A LITTLE MORE COOLING ALOFT...BUT STILL
UNCERTAINTY WITH COVERAGE GIVEN OVERALL BROAD SUBSIDENCE IN PLACE UNDER
RATHER WARM 5H TEMPS. CURRENT SPC/RNK WRF SOLUTIONS ALONG WITH THE
LATEST HRRR REMAIN THE MOST WIDESPREAD WITH SHRA/TSRA NORTH HALF AND
ALONG THE BLUE RIDGE. THIS WHILE MOST OTHER SOLUTIONS INCLUDING
ENSEMBLES PRODUCING LESS INCLUDING ONLY WIDELY SCATTERED SHALLOW
CONVECTION MAINLY CONFINED FROM THE VIRGINIA HIGHLANDS EAST TO AROUND
KLYH FOR THE MOST PART. THEREFORE ALIGNED HIGHEST CHANCE POPS ACROSS
THE FAR NORTH WITH A PERIOD OF LOWER CHANCES SOUTH/EAST DURING MID/LATE
AFTERNOON AND ONLY ISOLATED COVERAGE FAR SW. GIVEN WEAK FLOW ALOFT NOT
EXPECTING MUCH OF A SEVERE THREAT BUT COULD SEE A BIT MORE CLUSTERING
OF SLOW MOVING CONVECTION RIGHT NEAR THE CORE OF THE UPPER WAVE LATE.
OTHERWISE LOOKING AT MAINLY PC WITH MID DECK EARLY...THEN MORE CU THIS
AFTERNOON WITH HIGHS AGAIN REACHING THE LOW 90S EAST AND WELL INTO THE
80S ELSEWHERE PENDING TIMING OF CONVECTIVE INITIATION.
IMPULSE PASSES THIS EVENING LEAVING THE REGION IN BETWEEN WAVES AND
UNDER SURFACE HIGH PRESSURE. THIS SHOULD ALLOW MOST CONVECTION TO FADE
BY MIDNIGHT GIVEN LOSS OF HEATING AND SOME OVERNIGHT CLEARING PER WEAK
NW FLOW ALOFT IN THE WAKE OF THE MID LEVEL SYSTEM. THUS KEEPING SOME
LOW END CHANCE POPS GOING MAINLY EAST THIS EVENING BEFORE TRENDING DRY
WITH FOG AGAIN OVERNIGHT. LOWS PERHAPS SLIGHTLY COOLER GIVEN SOME DROP
IN DEWPOINTS AND ESPCLY WHERE ANY COOLING EVENING RAINFALL OCCURS BUT
STILL MOSTLY LOW/MID 60S MOUNTAINS TO UPPER 60S EAST.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 415 AM EDT WEDNESDAY...
WEAK UPPER-LEVEL SHORT WAVE WILL BE DISSIPATING ACROSS NORTH
CAROLINA DRIFTING SLOWLY INTO THE SOUTHEAST STATES WHERE IT
APPEARS IT IS DESTINED TO BECOME A WEAK CUTOFF THAT WILL
RETROGRADE/LINGER ACROSS THE SOUTHEAST/MID-SOUTH INTO NEXT WEEK AS
A LARGE HIGH AMPLITUDE UPPER RIDGE CONTINUES TO BUILD FROM THE
SOUTH CENTRAL/CENTRAL U.S. INTO SOUTHEAST CANADA AND THE NORTHEAST
U.S. OVER THE TOP OF THE WEAK CUTOFF LOW. UPPER SUPPORT WILL BE
MINIMAL AT BEST WITH BEST DYNAMICS...WHAT THEY ARE...HAVING
DRIFTED SOUTH OF THE AREA. ANY CONVECTION WILL LARGELY BE THE
RESULT OF DIFFERENTIAL HEATING AND FOCUSED PRIMARILY ACROSS THE
WESTERN MOUNTAINS. REALLY CANNOT SUPPORT MUCH MORE THAN 30 POPS AT
BEST.
BY FRIDAY...A LARGE SURFACE HIGH DEVELOPING ACROSS THE NORTHEAST
U.S. UNDERNEATH THE MAMMOTH UPPER RIDGE WILL BEGIN TO PUSH A
BACKDOOR FRONT FROM THE MID-ATLANTIC SOUTHWESTWARD. UPPER DYNAMICS
ARE VERY WEAK...BUT A MARKED DEWPOINT GRADIENT WILL EXIST ALONG
THE SOUTHWESTWARD ADVANCING BOUNDARY AS VERY DRY AIR ADVECTS
SOUTHWEST INTO NORTHERN VA. THIS SHOULD BE SUFFICIENT TO SUPPORT
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS...WITH THE BEST
COVERAGE SHIFTING SOUTHWEST TOWARD EVENING. INSTABILITY IS QUITE
NOTABLE ACROSS THE REGION IN ADVANCE OF THIS BACKDOOR FRONT...SO
EVEN WITH WEAK DYNAMICS...WITH THE NOTED INSTABILITY AND PWATS IN
THE 1.5 TO 1.7 INCH RANGE...30-40 PERCENT POPS SEEMS REASONABLE.
FOR SATURDAY...THE BACKDOOR FRONT CONTINUES TO DRIFT SOUTHWEST AND
SHOULD BE LOCATED FROM CENTRAL WV THROUGH SOUTHWEST VA...NEAR THE
I-77 CORRIDOR...INTO CENTRAL NC. VERY DRY AIR IS NOTED ADVECTING
INTO THE REGION FROM THE NORTHEAST WITH DEWPOINTS DROPPING INTO
THE 50S AND PWATS FALLING TO NEAR 0.50 INCH ACROSS THE NORTHEAST
PART OF THE CWA. ANY CONVECTION SATURDAY SHOULD BE LIMITED TO THE
I-77 CORRIDOR AND POINTS WESTWARD...PRIMARILY DURING THE
AFTERNOON/EVENING.
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL THURSDAY AND FRIDAY
AHEAD OF THE BACKDOOR FRONT...WITH MAX TEMPS WELL INTO THE
80S...NEAR 90 ACROSS THE PIEDMONT. MIN TEMPS WILL HOLD MOSTLY IN
THE 60S TO EVEN NEAR 70 ACROSS THE PIEDMONT. THESE READINGS ARE
AROUND 5 AND 10 DEGREES ABOVE NORMAL...RESPECTIVELY. MOS GUIDANCE
HAS BEEN TRENDING TOO MUCH TOWARD CLIMATOLOGY...SO NEEDED TO NUDGE
UP MOST AREAS FROM 2-3 DEGREES TO BETTER MATCH WHAT HAS BEEN
OCCURRING RECENTLY.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 445 AM EDT WEDNESDAY...
THE FOCUS THROUGH THE PERIOD WILL BE ON THE AFOREMENTIONED WEAK
AND INCREASING BROAD UPPER LOW ANCHORED ACROSS THE SOUTHEAST/MID-
SOUTH PART OF THE U.S. OUR CWA WILL BE STUCK IN THE TRANSITION
ZONE BETWEEN THIS INCREASINGLY MOIST/UNSTABLE AIR MASS TO THE
SOUTH AND THE PERSISTING UPPER RIDGE AND ASSOCIATED
SUBSIDENCE/VERY DRY AND WARM AIR MASS ACROSS THE MID-ATLANTIC
REGION. SHOWER/THUNDERSTORM CHANCES WILL GRADUALLY CREEP NORTHWARD
THROUGH THE PERIOD...BUT LIKELY REMAIN CONFINED TO AREAS WEST OF
I-77 SUNDAY...THEN CREEP FURTHER NORTH TOWARD THE U.S. 460
CORRIDOR BY MONDAY AND MUCH OF THE CWA BY TUESDAY. THE BEST
CHANCES THROUGHOUT THE PERIOD WILL REMAIN ACROSS THE WESTERN NC
MOUNTAINS. THE MODELS HAVE CONTINUALLY DELAYED THE ARRIVAL OF A
FRONT TOWARD THE MID PART OF NEXT WEEK...AND WITH THE UPPER RIDGE
SANDWICHED IN BETWEEN THE LOW PRESSURE AREA TO THE SOUTH AND THE
STRONGER WESTERLIES ALONG THE CANADIAN BORDER...IT MAY BE SOME
TIME BEFORE IT ACTUALLY REACHES OUR AREA. HENCE...SUMMER APPEARS
DESTINED TO HANG ON MUCH OF NEXT WEEK.
MAX TEMPS SHOULD BE NEAR NORMAL AT THE BEGINNING OF THE
PERIOD...BUT PERHAPS STILL SLIGHTLY ABOVE NORMAL WEST OF I-77. MIN
TEMPS WILL REMAIN NEAR NORMAL TO SLIGHTLY ABOVE NORMAL FAR
SOUTHWEST. MAX AND MIN TEMPS WILL CREEP TO SLIGHTLY ABOVE NORMAL
LEVELS AGAIN AS WE MOVE INTO EARLY NEXT WEEK.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 640 AM EDT WEDNESDAY...
FOG AND STRATUS REMAIN SPOTTY ACROSS THE REGION EARLY THIS MORNING
WITH THE TYPICAL VALLEY LOCATIONS SUCH AS KLWB/KBCB SEEING IFR OR
WORSE ATTM. EXPECT COULD SEE A BRIEF REDUCTION IN VSBY AS WELL
AROUND KLYH/KDAN AS WELL DURING THE NEXT HOUR OR TWO BEFORE
HEATING HELPS DISSIPATE ANY RESIDUAL LOW LEVEL MOISTURE. OTHERWISE
WAVES OF MID/HIGH CLOUDS AHEAD OF THE UPPER SYSTEM TO THE NW THE
MAIN ASPECT ONCE ANY LOW CLOUDS BURN OFF WITH VFR EXPECTED AT ALL
LOCATIONS FROM MID MORNING ONWARD.
UPPER WAVE OVER THE OHIO VALLEY WILL SHIFT SLOWLY SOUTHEAST INTO
VIRGINIA THIS AFTERNOON WHILE SLOWLY WEAKENING. THIS WILL ALLOW
MORE INSTABILITY WITH STEEPER LAPSE RATES AND LIFT. SHOWERS AND
STORMS WILL BE MORE SCATTERED THIS AFTERNOON WITH BEST FORCING
ACROSS THE NORTHERN FOOTHILLS/PIEDMONT TO THE NEW RIVER VALLEY.
AS OF NOW WILL KEEP THE GOING VCTS AT KROA/KLYH AND KBCB AFTER
19-20ZZ/3-4PM...BUT THINK COVERAGE WILL BE LESS FURTHER WEST AND
OVER THE SOUTHEAST...SO ONLY GOING WITH A VCSH AT KLWB-KBLF WHILE
KEEPING MENTION OUT OF KDAN FOR NOW. OVERALL EXPECT VFR
CONDITIONS OUTSIDE ANY CONVECTION INTO THIS EVENING WITH CIGS OF
4-6KFT WITH TCU AND CB IN THE AFTERNOON.
EXTENDED AVIATION DISCUSSION...
THE FORECAST AREA WILL REMAIN IN A WEAKLY FORCED SYNOPTIC
ENVIRONMENT THROUGH THURSDAY...WITH CHANCES FOR DIURNAL
CONVECTION MAINLY FROM THE BLUE RIDGE WEST...AND SOME MVFR/IFR
FOG/STRATUS DEVELOPMENT AT NIGHT...ESPECIALLY AT KBCB AND KLWB. A
WEAK BACKDOOR COOL FRONT MAY ENHANCE THE CHANCES FOR SHOWERS AND
STORMS LATER FRIDAY BEFORE DRIER AIR ARRIVES FRIDAY NIGHT.
FOR SATURDAY INTO SUNDAY WILL SEE HIGH PRESSURE IN CONTROL THOUGH
THE POSITION OF THE HIGH OVER THE MID ATLANTIC MAY SLIDE MORE MVFR
CIGS OFF THE ATLANTIC INTO OUR EASTERN TAF LOCATIONS AT LEAST TO
START THE WEEKEND.
&&
.EQUIPMENT...
AS OF 400 PM EDT TUESDAY...
THE DEW POINT READING AT KJFZ...RICHLANDS VA AWOS...IS INCORRECT.
AT THIS TIME WE DO NOT KNOW WHEN THIS SENSOR WILL BE REPAIRED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...JH
SHORT TERM...RAB
LONG TERM...AMS/RAB
AVIATION...JH/NF/WP
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
630 AM CDT WED SEP 2 2015
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 300 AM CDT WED SEP 2 2015
DATA ANALYSIS THIS MORNING FEATURES A MID-LEVEL TROUGH/MCV MAKING
ITS WAY ACROSS SOUTH-CENTRAL MN/CENTRAL IA TOWARD THE UPPER
MISSISSIPPI RIVER VALLEY REGION. THERE HAS BEEN SOME EFFICIENT RAIN-
MAKERS EMBEDDED WITHIN THIS COMPLEX OF CONVECTION GIVEN HUMID/HIGHER
PRECIPITABLE WATER ENVIRONMENT. FEW HOURLY PRECIPITATION REPORTS
COMING IN FROM 3/4 TO JUST OVER AN INCH. OTHERWISE...MUGGY EARLY
MORNING ACROSS THE AREA WITH TEMPERATURES/DEW POINTS IN THE UPPER
60S TO THE MIDDLE 70S.
WILL BE WATCHING THE TROUGH/MCV CONTINUE MOVING ACROSS OUR AREA
TODAY. RAP SHOWING DECENT PUSH OF 850-700MB MOISTURE TRANSPORT
CONTINUING THROUGH 18Z. SO...EXPECTING THIS CONVECTIVE COMPLEX TO
HOLD TOGETHER THROUGH THIS MORNING WITH CHANCES FALLING OFF DURING
THE AFTERNOON FROM WEST TO EAST AS BETTER MOISTURE PUSHES EAST WITH
THE TROUGH. HIGHEST CONCENTRATION OF SHOWERS/STORMS LOOK TO BE NORTH
OF I-90 OR NOSE OF THE BETTER 850-700MB MOISTURE TRANSPORT. ALTHOUGH
SEVERE WEATHER IS NOT ANTICIPATED TO BE WIDESPREAD TODAY GIVEN LOW-
END BULK SHEAR FOR ORGANIZATION...COULD BE SOME SPORADIC HIGHER WIND
GUSTS MIXED IN WITH HEAVIER DOWNPOURS. PLAN ON MUGGY CONDITIONS
OTHERWISE WITH HIGHS IN THE 80S AND DEW POINTS STAYING IN THE UPPER
60S TO LOWER 70S. THIS WILL PUT HEAT INDICES IN THE 90-95 DEGREE
RANGE MAINLY SOUTH OF I-90.
LINGERING SHOWER/THUNDERSTORM CHANCES CONTINUE THROUGH TONIGHT AS
WANING 850-700MB MOISTURE TRANSPORT IMPINGES ON SURFACE TROUGH/WARM
FRONTAL BOUNDARY EAST OF THE MISSISSIPPI RIVER. LOOK FOR MUGGY
OVERNIGHT TEMPERATURES IN THE MIDDLE 60S TO NEAR 70.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 300 AM CDT WED SEP 2 2015
ISOLATED TO SCATTERED SHOWERS/THUNDERSTORMS STILL POSSIBLE ACROSS
CENTRAL WISCONSIN THURSDAY AS THIS AREA WILL BE ALONG THAT
AFOREMENTIONED SURFACE TROUGH/WARM FRONTAL BOUNDARY AND VERY WEAK
850MB MOISTURE TRANSPORT. OTHERWISE...ANOTHER MUGGY DAY ON TAP WITH
HIGHS IN THE 80S AND DEW POINTS HANGING IN THE UPPER 60S/LOWER 70S.
HEAT INDICES ARE EXPECTED TO TOP OFF IN THE 90-95 DEGREE RANGE.
FRIDAY APPEARS DRY BUT RAIN CHANCES INTO THE WEEKEND WILL HANG ON
DISTURBANCES EJECTING OUT OF MONSOONAL FLOW OVER THE SOUTHWEST.
MODELS SEEM TO BE HAVING A DIFFICULT TIME HANDLING THESE FEATURES IN
DETAIL...YIELDING LOW-END SHOWER/THUNDERSTORM CHANCES SATURDAY.
APPEARS LATEST ECMWF/GFS ARE CONVERGING ON SLIGHTLY FASTER TIMING ON
INCOMING MID-LEVEL TROUGH/SURFACE COLD FRONT FROM THE NORTHERN
PLAINS SUNDAY INTO MONDAY. APPEARS HIGHEST SHOWER/THUNDERSTORM
CHANCES WILL BE SUNDAY NIGHT WITH THE COLD FRONT POSSIBLY CLEARING
THE AREA BY AFTERNOON ON LABOR DAY. OTHERWISE...STILL LOOKING HOT
AND MUGGY SATURDAY AND SUNDAY WITH HIGHS WELL INTO THE 80S AND HEAT
INDICES IN THE UPPER 80S TO MIDDLE 90S.
TUESDAY WILL SEE A CHANCE OF SHOWERS AND STORMS ACROSS NORTHEAST IA
INTO FAR SOUTHWEST WI AS THE COLD FRONT STALLS OUT JUST SOUTH OF
THAT AREA. COOLER/DRIER AIR IS ON TAP OTHERWISE WITH HIGHS LOOKING
TO BE IN THE UPPER 60S ACROSS NORTHERN WI...TO THE LOWER/MIDDLE 70S
SOUTH OF I-90.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 630 AM CDT WED SEP 2 2015
02.1130Z REGIONAL RADAR SHOWS A LINE OF SHOWERS WITH EMBEDDED
THUNDERSTORMS FROM NORTH-CENTRAL WI TO SOUTHEAST MN AND INTO
EASTERN IA...MOVING EAST-NORTHEAST AROUND 25 KTS. EXPECT THIS
LINE OF STORMS TO IMPACT BOTH KRST/KLSE...ALTHOUGH IT SHOULD
WEAKEN AS IT MOVES EAST. COULD SEE BRIEF MVFR CEILINGS/VISIBILITY
AT KRST AS STRONGEST STORMS MOVE THROUGH BETWEEN 02.12Z AND
02.14Z...BUT WILL KEEP VFR CONDITIONS AT KLSE WITH STORM TIMING
FROM 02.13Z TO 02.15Z. ONCE STORMS MOVE EAST OF TAF AIRFIELDS...
EXPECT A RETURN TO VFR CONDITIONS WITH ONLY SOME AFTERNOON CUMULUS
BEFORE CLEARING OUT THIS EVENING AND OVERNIGHT. DESPITE MOSTLY
CLEAR SKIES TONIGHT...THINK WESTERLY WINDS FROM 20 TO 30 KTS AT
THE TOP OF NOCTURNAL BOUNDARY LAYER WILL PRECLUDE FOG FORMATION.
COULD SEE SOME MVFR VISIBILITY IN MIST...BUT NOT ENOUGH
CONFIDENCE TO INCLUDE AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...ROGERS
AREA FORECAST DISCUSSION
NWS PUEBLO CO
308 PM MDT WED SEP 2 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 307 PM MDT WED SEP 2 2015
CONVECTION SLOWLY BEGINNING TO INCREASE ACROSS THE AREA THIS
AFTERNOON...WITH STORMS MOST NUMEROUS OVER THE SOUTHWEST MOUNTAINS
AND ALONG THE NM BORDER WHERE MOISTURE AND INSTABILITY IS GREATEST.
FOR THE REST OF THE AFTERNOON INTO THE EVENING...EXPECT CONVECTION
TO EXPAND SOMEWHAT OVER THE MOUNTAINS AND INTERIOR VALLEYS AS WEAK
UPPER WAVE AND INCREASING MID LEVEL MOISTURE MOVE INTO CO FROM NWRN
NM. HRRR SUGGESTS SOME WEAKENING STORMS TO PERHAPS REACH THE I-25
CORRIDOR AROUND KPUB AND KCOS THIS EVENING...THOUGH RATHER LOW CAPE
(200-400 J/KG) ACROSS THESE AREAS SUGGESTS STORMS WILL STAY ISOLATED
AND WEAK. A FEW STORMS WILL ALSO BE POSSIBLE ALONG THE NORTH SLOPE
OF THE RATON MESA EASTWARD ACROSS LAS ANIMAS COUNTY...WHILE
REMAINDER OF THE PLAINS SHOULD BE TOO STABLE TO SUPPORT ANY EVENING
CONVECTION. OVERNIGHT...STORMS WILL END OVER THE EASTERN HALF OF THE
AREA...WHILE A FEW -SHRA/WEAK -TSRA HANG ON ALONG THE CONTINENTAL
DIVIDE WHERE MOISTURE CONTINUES TO ADVECT NORTHWARD FROM AZ/NM.
ON THU...EXPECT FAIRLY WIDESPREAD CONVECTION OVER THE MOUNTAINS FROM
THE SANGRES WESTWARD AS DEEP MOIST AIR MASS WILL BE OVER THE
AREA...WHILE EASTERN MOUNTAIN SLOPES/I25 CORRIDOR/SOUTHEAST PLAINS
SEE MUCH LESS ACTIVITY UNDER RATHER UNFAVORABLE W-SW WINDS AT THE
SURFACE AND ALOFT. GIVEN RATHER HEALTHY PRECIPITABLE WATER
VALUES...STORMS OVER THE HIGHER TERRAIN WILL HAVE THE POTENTIAL FOR
FAIRLY HEAVY RAINFALL RATES...THOUGH RELATIVELY STRONG STEERING
CURRENTS SHOULD KEEP ACTIVITY MOVING AND REDUCE THE FLOOD HAZARD
SOMEWHAT. MAX TEMPS OVER THE MOUNTAINS AND VALLEYS SHOULD COOL A FEW
DEGF FROM WED MAXES...WHILE I-25 CORRIDOR AND EASTERN PLAINS SEE
LITTLE CHANGE WITH RATHER HOT TEMPS PERSISTING.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 307 PM MDT WED SEP 2 2015
THURSDAY NIGHT THROUGH SATURDAY...FAIRLY GOOD MODEL AGREEMENT
BETWEEN THE GFS AND EC INTO THE WEEKEND...AS COLORADO REMAINS IN THE
MIDDLE OF A RIDGE OF HIGH PRESSURE TO THE EAST.,..AND A
STRENGTHENING LOW PRESSURE SYSTEM OVER THE PAC NW. THIS WILL PRODUCE
BRISK SW FLOW ALOFT ACROSS THE 4 CORNERS AND COLORADO...DRAWING A
HEALTHY AMOUNT OF MONSOON MOISTURE INTO THE FORECAST AREA. THIS WILL
ALSO ENCOURAGE DIURNAL CONVECTION EACH AFTN AND EVENING...WITH
ISOLATED TO SCATTERED POPS OVER THE MTS AND ISOLATED ELSEWHERE. LOOK
FOR MILD NIGHTS...AND MAX TEMPS EACH AFTN IN THE 70S TO NEAR 80 FOR
THE HIGH VALLEYS...AND AROUND 90 F FOR THE E PLAINS.
SUNDAY AND MONDAY...MODELS START TO DISAGREE BEGINNING ON SUN. THE
UPPER LOW OVER THE PAC NW WILL ROTATE ACROSS THE NORTHERN ROCKIES ON
SAT...MT ON SUN AND BACK NORTH INTO CANADA FOR MON. THE FLOW ALOFT
WILL TRANSITION TO A MORE WESTERLY DIRECTION...TEMPORARILY CUTTING
OFF THE MONSOON TAP FROM THE SW. MODELS SOMEWHAT AGREE ON THIS...BUT
THE GFS STARTS TO SNEAK MOISTURE BACK UP INTO THE STATE MON AFTN AND
EVE. FEEL THIS IS REASONABLE SINCE THERE WILL STILL BE PLENTY OF
DAYTIME HEATING...SO KEPT ISOLATED POPS OVER THE MTS...MAINLY ALONG
THE CONTDVD...MON AFTN AND EVE.
TUESDAY AND WEDNESDAY...THE EC LEANS TOWARDS KEEPING THE ENTIRE AREA
DRY THROUGH WED...WHILE THE GFS HAS MORE OF A SW FLOW ALOFT WHICH
ATTEMPTS TO DRAW SOME OF THE MONSOON MOISTURE BACK INTO THE STATE.
DECIDED TO SIDE WITH THE GFS...BUT KEPT POPS LIGHT THROUGH WED WHILE
COOLING MAX TEMPS BOTH DAYS BY ABOUT 5 DEGREES. MOORE
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 307 PM MDT WED SEP 2 2015
TSRA WILL REMAIN CONFINED MAINLY TO THE MOUNTAINS/INTERIOR VALLEYS
INTO THIS EVENING...AND WILL CARRY A VCTS MENTION ONLY AT KALS FOR
LATE AFTERNOON INTO THE EVENING. COULD SEE SOME VERY WEAK CONVECTION
DRIFT OFF THE MOUNTAINS TOWARD KCOS AND KPUB 23Z-03Z...BUT DOUBTFUL
THEY WILL LAST LONG ENOUGH TO REACH EITHER TERMINAL AND WON`T
INCLUDE A MENTION IN THE TAFS AT THIS POINT. OVERNIGHT...SOME WEAK
CONVECTION WILL LINGER ALONG THE CONTINENTAL DIVIDE INTO THU
MORNING...WITH POSSIBLY SOME MVFR CIGS/VIS OVER THE HIGHER PEAKS AND
PASSES. ON THU...CONVECTION WILL BECOME FAIRLY WIDESPREAD BY
AFTERNOON OVER THE MOUNTAINS...ESPECIALLY ALONG THE CONTINENTAL
DIVIDE WHERE AREAS OF IFR CONDITIONS WILL BE LIKELY THROUGH THE DAY.
FOR THE TAF SITES...BEST CHANCE OF TSRA THU WILL BE AT KALS...LESSER
CHANCES AT KPUB AND KCOS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...MOORE
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS MIAMI FL
353 PM EDT WED SEP 2 2015
.DISCUSSION...
ISOLATED TO SCATTERED THUNDERSTORMS CONTINUE ACROSS MAINLY THE
EAST COAST METRO AREAS WITH A RATHER WEAK EAST COAST SEA BREEZE.
OVER THE NEXT FEW HOURS...ADDITIONAL CONVECTION IS EXPECTED TO
DEVELOP MAINLY WEST OF THE EAST COAST METRO AREAS DUE TO
SUBSEQUENT OUTFLOW BOUNDARY INTERACTIONS. LATEST HRRR AGREES BY
PUSHING MOST OF THE LATER CONVECTION ACROSS THE NORTHWEST INTERIOR
THROUGH THE LATE AFTERNOON AND EARLY EVENING HOURS. MAIN THREATS
WITH THESE STORMS WILL BE FREQUENT LIGHTNING AND BRIEF HEAVY
DOWNPOURS.
UPPER RIDGING IS STILL EXPECTED TO BE THE MAIN WEATHER FEATURE
ACROSS SOUTH FLORIDA THROUGH THE REMAINDER OF THE WEEK AND INTO
THE FIRST PART OF THE WEEKEND. THIS WILL KEEP SURFACE WINDS AND
STEERING FLOW GENERALLY LIGHT WITH AFTERNOON AND EARLY EVENING
CONVECTION REMAINING MAINLY ACROSS THE INTERIOR.
BY LATE IN THE WEEKEND THROUGH THE EARLY PART OF NEXT WEEK...UPPER
RIDGING IS EXPECTED TO BREAK DOWN AS A BROAD H5 TROUGH DIGS
SOUTHWARD THROUGH THE FLORIDA PENINSULA AND INTO THE EASTERN GULF
OF MEXICO. THIS WILL USHER IN A MORE SOUTHWESTERLY MID LEVEL FLOW.
MODELS ALSO HINT AT SLIGHTLY DRIER AIR PUSHING INTO THE AREA
DURING THIS TIME FRAME WHICH WILL DO LITTLE MORE THAN DECREASE
POPS SLIGHTLY FOR THE EARLY TO MID WEEK TIME FRAME NEXT WEEK.
&&
.AVIATION...
CONVECTION IS EXPECTED TO STAY AWAY FROM THE EAST COAST SITES
THROUGH THE REMAINDER OF THE AFTERNOON. LATEST HRRR KEEPS
ADDITIONAL OUTFLOW BOUNDARY DRIVEN CONVECTION ACROSS THE INTERIOR
INTO THE EARLY EVENING HOURS...SOME POSSIBLY AFFECTING KAPF.
OTHERWISE...LIGHT SOUTH TO SOUTHEASTERLY FLOW TO PREVAIL.
&&
.MARINE...
RATHER TRANQUIL MARINE CONDITIONS ARE EXPECTED THROUGH THE NEXT
COUPLE OF DAYS WITH LIGHT EAST TO SOUTHEAST WIND OF LESS THAN 10 KNOTS
AND SEAS OF 2 FEET OR LESS ACROSS ALL WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 77 92 77 92 / 20 30 30 50
FORT LAUDERDALE 79 91 78 92 / 20 30 30 60
MIAMI 78 92 78 93 / 20 30 30 60
NAPLES 78 90 78 90 / 20 30 10 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...10/CD
LONG TERM....10/CD
AVIATION...10/CD
AREA FORECAST DISCUSSION
NWS POCATELLO ID
233 PM MDT WED SEP 2 2015
.DISCUSSION...STRONG LOW PRESSURE DISTURBANCE CONTINUES TO MOVE
SOUTH ALONG THE COAST TOWARDS SOUTHERN OREGON AND NORTHERN
CALIFORNIA. SOME SOUTHERLY FLOW INTO SOUTHEAST IDAHO THIS
AFTERNOON WITH POTENTIAL FOR SUBTROPICAL MOISTURE SLIPPING INTO
THE SOUTH CENTRAL AND CARIBOU HIGHLANDS THIS EVENING AND
OVERNIGHT. LATEST SATELLITE AND RADAR IMAGERY SUGGEST THIS HAS
BEEN DELAYED A BIT AND THE 18Z NAM12 AND RAP MODEL ALSO FAVOR
TIMING CLOSER TO MIDNIGHT AND EARLY MORNING. THE REMAINDER OF
SOUTHEAST IDAHO REMAINS DRY TONIGHT. THURSDAY AND THURSDAY NIGHT
STILL LOOKING FOR THE EASTERN EDGE OF THE LOW TO BRUSH CUSTER
COUNTY WITH A FEW SHOWERS AS IT MOVES SOUTH. THERE WILL BE A FEW
TRICKLES OF MOISTURE SLIPPING INTO THE EASTERN HIGHLANDS FROM THE
SOUTH AS WELL. SOUTHERLY WINDS FRIDAY WILL BE BREEZY IN THE SOUTH
CENTRAL HIGHLANDS AND SNAKE PLAIN.
MODEL CONSENSUS HAS THE LOW MOVING EAST INTO IDAHO FRIDAY NIGHT
AND SATURDAY FOR SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER
THE FORECAST AREA. BY SUNDAY THE PATTERN QUICKLY REVERTS BACK TO A
MILD WEST TO NORTHWEST FLOW THAT IS LARGE DRY EXCEPT FOR MAY NEAR
MONIDA PASS ON THE MONTANA BORDER. THERE ARE SOME MODEL
DIFFERENCES WITH A MINOR DISTURBANCE THAT CROSSES NORTH IDAHO AND
MONTANA ON MONDAY AND NIPPING THIS AREA WITH SPOTTY SHOWERS...THEN
IT IS BACK TO A DRY PATTERN THE LATER PART OF THE WEEK. RS
&&
.AVIATION...MODELS PROJECT A DISTURBANCE TO MOVE NORTH OUT OF UTAH
THIS EVENING AND PRODUCE SHOWERS FOR KPIH AND KIDA. AN ISOLATED
LIGHTNING STRIKE CANNOT BE RULED OUT...BUT NOT ENOUGH CONFIDENCE TO
INCLUDE IN TAFS. THE DISTURBANCE WILL CONTINUE NORTHWARD AND WILL
LIKELY EXIT INTO MT/WY BEFORE SUNRISE. HINSBERGER
&&
.FIRE WEATHER...RED FLAG CONDITIONS CONTINUE THROUGH 9 PM THIS
EVENING DUE TO GUSTY WINDS AND LOW HUMIDITY. A STRONG SOUTHWESTERLY
BOUNDARY LAYER FLOW AHEAD OF A COLD FRONT WILL IMPACT THE CENTRAL
IDAHO MOUNTAINS. THIS FLOW PARTICULARLY FAVORS DRY/WARM DOWNSLOPE
WINDS IN THE VALLEYS UNTIL JUST AFTER SUNSET TONIGHT. THE COLD FRONT
WILL STALL OVER THE CENTRAL MOUNTAINS OVERNIGHT AND PASS THROUGH
THURSDAY NIGHT. HUMIDITY IS GENERALLY EXPECTED TO RECOVER AND WINDS
SHOULD NOT BE AS STRONG ON THURSDAY. MOISTURE INCREASES SATURDAY AS
SOUTHERLY FLOW IS ENHANCED AHEAD OF A DEEP UPPER LOW...WHICH MAY
BRING WETTING RAINS TO THE CENTRAL MOUNTAINS. THE LOW WILL ALSO
BRING THE THREAT OF THUNDERSTORMS AS THE AIRMASS BECOMES MORE
UNSTABLE. HINSBERGER
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR IDZ410-475-476.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
343 PM CDT WED SEP 2 2015
.SHORT TERM...(THIS EVENING THROUGH Thursday)
ISSUED AT 307 PM CDT WED SEP 2 2015
19z sfc map shows low pressure across the northern plains with a
trough extending south into western KS with most of eastern Kansas
now mixed out into the warm sector as remnants of elevated
convection wane. Water vapor loop shows a wave across Nebraska
moving E along the northern periphery of the upper ridge axis.
For tonight, the wave will track into northern MO overnight and may
help to enhance the LLJ which will contribute to modest WAA around
850mb. There is some additional WAA fcst to occur around the 700mb
level as well. Interesting that both the RAP and HRRR and GFS are
showing some small areas of QPF across central KS overnight despite
the 850mb thetae ridge remaining north of the CWA overnight. This
appears to be due to modest lift and saturation around 700-650mb
where even the NAM soundings show saturation after 6z. Fcst
soundings suggest modest elevated CAPE of 100j/kg or less. Other
convective models do not show this weak lift resulting in saturation
or convection so for now will keep the pops below 15 and keep the
fcst dry but something to watch for overnight.
We should see another day much like today on Thursday with 1000-
850mb thickness and temps nearly identical to today so will go with
persistence for temps. Pressure gradient is also similar so look for
another breezy day as well.
.LONG TERM...(Thursday NIGHT THROUGH Wednesday)
ISSUED AT 307 PM CDT WED SEP 2 2015
Thursday night through Saturday...Deep, moist southerly low-level
flow will continue through the period. With stronger south-
southwest flow aloft off to our west and northwest, no
recognizable dynamic feature is depicted in the short range
guidance to focus showers and thunderstorms in eastern KS. Only
possibility would be the remnants of some High Plains convective
cluster that might migrate into north central KS/south central/NE
before dissipating. Would expect any system like that to die out
before affecting our northwestern forecast area.
Saturday night through Wednesday...Strong upper trough over the
Rockies on Saturday evening will move northeast into southern
Manitoba and become an occluded system by Monday morning. While
strong dynamics are well to the north, southern extent of system
is a cold front that moves into central/eastern KS and then
becomes nearly stationary. This will be the focus for thunderstorm
chances late in the weekend into early next week. Medium range
models have some differences in the location of this boundary
already by Monday, but all depict it in the area with periodic
chances of thunderstorms into Tuesday night/Wednesday morning.
Then another strong trough moves across the central U.S. with the
result that the front pushes south of the area by late Wednesday.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Thursday AFTERNOON)
ISSUED AT 1232 PM CDT WED SEP 2 2015
VFR conditions are expected for the duration of the TAF period at
all terminals. However, wind gusts of 20-25 knots from the south
are expected at all terminals through 1Z this evening. Wind gusts
will also be a concern after 15Z tomorrow morning as 20-25 knot
gusts are expected.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Omitt
LONG TERM...GDP
AVIATION...Omitt/Baerg
AREA FORECAST DISCUSSION
NWS PADUCAH KY
218 PM CDT WED SEP 2 2015
.SHORT TERM...(This evening through Friday Night)
Issued at 218 PM CDT WED SEP 2 2015
Upper level disturbance in the lower Mississippi River Valley was
causing some isolated showers to our southwest this
afternoon...with a few cells getting fairly close to our SEMO
counties. The RUC and HRRR models seem to be overdone by showing
some activity developing over us this afternoon. Cu field looks
fairly shallow right now, but will continue to monitor for any
isolated development. The aforementioned upper level feature will
shift east tonight.
The 12Z model consensus continues to advertise high pressure at the
surface and aloft that will keep the area mainly dry through
Friday. The only exception to this may be on Thursday night into
Friday when some energy may drop south on the east side of the
upper high. Not every model is advertising any QPF and there
really isnt too much moisture to work with other than a shallow
layer between 850-700mb. But an isolated or widely scattered storm
is possible. Too low of a probability to mention in the forecast
but would not be surprised to see a few cells out there.
Temperatures will remain above normal. Looks like low level temps
rise a degree or so for tomorrow and given the abundant
sunshine...believe we could be a tad warmer on Thursday. Some of the
guidance supports this notion as well. We could see temperatures
drop a degree or so in the eastern sections on Friday though as the
upper ridge breaks down a bit there. However, it will still be
fairly warm. Lower 90s for highs and upper 60s to around 70 degrees
for lows looks to be the norm for the next few days along with light
and variable winds.
.LONG TERM...(Saturday through Wednesday)
Issued at 218 PM CDT WED SEP 2 2015
Average confidence in the short term period due to model
differences, especially toward the end of the period. Very few
changes to the long term with not much to discuss.
At the beginning of the long term period, weak high pressure at the
surface and aloft will be the predominant features affecting our
CWA`s weather, therefore dry conditions are forecast for the first
couple of days.
Beyond that and through most of the long term period, the
development of weaknesses or slight shifting of the axis of the
aforementioned high pressure will make it possible for isolated to
scattered convection to pop up given the moisture and instability
already in place.
With the approach and passage of a cold front, precipitation chances
slowly increase and eventually overspread the entire CWA by the end
of the period.
Above normal temperatures at the beginning of the period will slowly
cool back to near normal readings by the end of the period.
&&
.AVIATION...
Issued at 218 PM CDT WED SEP 2 2015
Surface high pressure will keep winds light and variable through
the day. As they go calm overnight, some at least MVFR fog is
likely to develop at all sites, similar to this morning. More
cumulus is expected again on Thursday...similar to the level they
are at today. Winds will be light and variable again Thursday...at
least prior to 18Z.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
344 PM CDT WED SEP 2 2015
.SHORT TERM... NOT MUCH HAS CHANGED TO THE UPPER LEVEL PATTERN IN
GENERAL ACROSS THE SOUTHEASTERN UNITED STATES HAS CHANGED MUCH. BUT
ALL IT TOOK WAS AN INVERTED TROUGH CENTERED JUST TO THE WEST OF THE
FORECAST AREA TO SHIFT SLIGHTLY EAST TO ALLOW MORE MOISTURE IN FROM
THE GULF. THE RESULTS FROM THIS CHANGE CAN CLEARLY BE SEEN ON RADAR.
A WIDE BLANKET OF LIGHT TO MODERATE RAIN EXTENDS FROM THE OFFSHORE
WATERS SOUTH OF LOUISIANA NORTHWARD TO INTERSTATE 12. THE ATMOSPHERE
APPEARS TO BE SLIGHTLY MORE STABLE INLAND VS ALONG THE COAST WHERE
MOST OF THE LIGHTNING HAS BEEN OCCURRING. NORTHWARD PROGRESSION OF
RAINFALL ACROSS THE CWA SHOULD BE JUST ABOUT DONE. THE HRRR HAS BEEN
PERFORMING WELL TODAY AND IT SUGGESTS MUCH OF THE ACTIVITY SHOULD BE
ON A DOWNWARD TREND SOON AND MOST OF THE INLAND SHOWERS DISSIPATED
BY 00Z-02Z. AFTER THAT...FAIRLY QUIET DURING THE EVENING HOURS WITH
SHOWERS REDEVELOPING OFFSHORE ALONG THE LA COAST EARLY TOMORROW
MORNING AND THEN A SIMILAR REPEAT FOR THURSDAY. HAVE INCREASED RAIN
CHANCES FOR PORTIONS OF THE CWA SOUTH OF LAKE PONTCHARTRAIN TO THE
COAST TO ACCOUNT FOR THIS.
.LONG TERM... THE UPPER LEVEL PATTERN OVER THE CWA WILL REMAIN
SIMILAR THROUGH THE WEEKEND WITH WEAKNESS ALOFT WHICH WILL PROMOTE
DAILY POPS IN THE 30 TO 50 PERCENT RANGE. HIGH PRESSURE WILL TRY TO
REBUILD ITSELF TO THE WEST OF THE REGION EARLY NEXT WEEK BUT STILL
BEING EAST OF THIS AREA IN LA/MS...LIKELY TO HAVE CONTINUED SHOWER
AND THUNDERSTORMS DEVELOP IN THE AFTERNOONS.
MEFFER
&&
.AVIATION...
EXPECT VFR CONDITIONS TO DOMINATE THE PERIOD ACROSS ALL TERMINALS.
IN THE SHORT TERM THOUGH QUITE EXTENSIVE MID AND HIGH CLOUD DECK
ACROSS MUCH OF THE AREA FROM THUNDERSTORMS THAT HAVE MOVED ONSHORE
FROM THE GULF DURING THE MORNING HOURS. THE CONVECTION THAT WILL
IMPACT MOST TERMINALS IS DOING SO AT THIS TIME. MOST ACTIVITY SHOULD
DISSIPATE BY AROUND 00Z-02Z BEFORE RETURNING TOMORROW.
MEFFER
&&
.MARINE...
RELATIVELY BENIGN CONDITIONS FOR THE NEXT SEVERAL DAYS WITH A WEAK
PRESSURE PATTERN CONTROLLING THE WEATHER. WINDS GENERALLY LESS THAN
10 KNOTS WITH SEAS 2 FEET OR LESS. SCATTERED CONVECTION POSSIBLE
JUST ABOUT EVERY DAY OF FORECAST AFTER TODAY. THIS ACTIVITY MAY
PRODUCE WIND GUSTS TO 30 KNOTS OR BETTER AT TIMES AS IT MOVES OUT OF
THE GULF. 35
&&
.DECISION SUPPORT...
DSS CODE....GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...NONE.
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 RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 72 94 73 94 / 10 30 10 30
BTR 72 92 74 92 / 10 30 10 30
ASD 76 90 76 90 / 20 50 20 30
MSY 77 88 77 89 / 20 50 20 40
GPT 77 89 78 90 / 20 50 20 30
PQL 76 90 76 90 / 20 50 20 30
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
148 PM CDT WED SEP 2 2015
.UPDATE...
BUMP HIGHS ANOTHER CATEGORY AND SHAVE DEEP E TX POPS.
&&
.DISCUSSION...
AIR TEMPERATURES HAVE TAKEN A BIG JUMP OVER THE LAST COUPLE OF
HOURS AND WITH THE THICK MID DECK ALREADY NORTH OF SHREVEPORT THE
LOWER 90S WOULD NOT LIKELY HOLD. ALSO...WE HAVE TWEAKED POPS A
TAD WHERE CU FIELD HAS BEEN SLUGISH TO DEVELOP ANY TOWERS. /24/
&&
.PREV DISCUSSION... /ISSUED 1158 AM CDT WED SEP 2 2015/
AVIATION...
MID LVL CLOUD DECKS ACROSS THE AREA INHIBITING CUMULUS DEVELOPMENT
IN MOISTER AIR UNDERNEATH. CONVECTION THUS FAR TODAY HAS REMAINED
JUST OFFSHORE IN GULF AND NE MOVMT OF CELLS COULD POSSIBLY TRAJECT
TOWARDS KMLU LATER THIS AFTN...SO PLACED TSTM VCNTY AT THAT
TERMINAL BUT NONE ELSEWHERE. FOG AND LOW CLOUDS TONIGHT LIMITED IN
LACK OF SOUTHERLY FLOW OR RECENT FOG DEVELOPMENT ACROSS AREA...BUT
IF SO...KLFK WOULD BE MOST LIKELY TERMINAL TO SEE ANY TEMPO MVFR
CONDITIONS OVERNIGHT. LGT VRBL WINDS ACROSS AREA TO REMAIN UNTIL
AT LEAST 03/15Z WITH ONLY SE WINDS AROUND 5 KTS AFTER THAT./VII/.
PREV DISCUSSION... /ISSUED 1137 AM CDT WED SEP 2 2015/
UPDATE...
A FEW MINOR CHANGES TO AFTERNOON POPS/SKY AND HIGH TEMPERATURES.
DISCUSSION...
ADD 10 AT 10 CST RULE WITH OBS RANGING ALL THROUGH THE 80S. A
DENSE MID DECK IS WORKING OVER THE HEART OF THE ARKLATEX WITH LOW
80S AND LIGHT OR CALM SFC WINDS. RUSTON AND MONROE ARE IN THE
UPPER 80S WITH A GOOD DEAL MORE SUNSHINE THIS MORNING. OUR RADAR
HAS A CLEAN SWEEP AND WITH LIMITED HEATING AND THAT MAY BE
THROUGH THE LUNCH HOUR.
OUR SOUNDING SHOWED MOISTURE INTO THE MID LEVELS...BUT VERY DRY
ABOVE AN INVERSION AT 18KFT. IT IS LIKELY THAT THE NE FLOW ABOVE
THE INVERSION HAS WORKED DOWN A BIT LOOKING AT THE WATER VAPOR.
ANY THUNDERSTORMS TODAY WILL BE LOW TOPPED AND PERHAPS FEW AND FAR
BETWEEN. MIDDECK SHOWERS ARE MORE LIKELY UNTIL WE SEE BETTER
HEATING THIS AFTERNOON. THE VAPOR SHOWS THE DRY AIR SPREADING SE
FOR THE LAST FEW HOURS...BUT HAS SLOWED ITS MOTION. THERE IS A
LITTLE VORT WORKING UP ACROSS W LA IN OVER TOLEDO BEND COUNTRY.
THIS MAY HELP WITH SOME CHANCE POPS FOR I-20 CORRIDOR LATER WITH
MORE HEATING AS THE MID DECK MOVES FARTHER NW.
THE HRRR SHOWS DECENT COVERAGE AND IS WHY WE LEFT CHANCE POPS.
SLIGHT CHANCE MAY BE A MORE LIKELY EVENT IF THAT LITTLE VORT FAILS
TO SPREAD DEEPER TROPICAL MOISTURE BACK INTO THAT DRIER AIR. THE
CHANCE FOR RAIN STILL LOOKS TO DECLINE INTO THE NEXT FEW DAYS AS
THE MAIN GULF LOW MOVES EASTWARD...TAKING THE TROPICAL CONNECTION
OUT OF REACH. /24/
PREV DISCUSSION... /ISSUED 412 AM CDT WED SEP 2 2015/
DISCUSSION...
WATER VAPOR IMAGERY CONTINUES TO DEPICT A WEAK UPPER LEVEL LOW
NEAR GALVESTON BAY THIS MORNING WITH A SHEAR AXIS EXTENDING NWRD
ACROSS DEEP E TX...N LA...AND SE AR. MID AND HIGH CLOUDS CONTINUE
TO BLANKET THESE AREAS WHILE POINTS ALONG AND NORTH OF THE I-30
CORRIDOR ARE SKC. AS MOISTURE REMAINS QUITE ABUNDANT OVER THE SE
HALF OF THE REGION TODAY...EXPECT SHWRS AND TSTMS TO INCREASE AS
WE MOVE INTO THE AFTERNOON HOURS WITH THE ADDED INSTABILITY FROM
HEATING. USING PERSISTENCE AS A GUIDE...DO EXPECT CLOUD COVER TO
HOLD DOWN TEMPERATURES SLIGHTLY MUCH LIKE YESTERDAY WITH UPPER 80S
AND LOWER 90S EXPECTED.
RAIN CHANCES WILL BEGIN TO DROP OFF AS WE HEAD INTO LATE WEEK AND
THE LABOR DAY WEEKEND AS UPPER RIDGING BECOMES MORE INFLUENTIAL IN
OUR WEATHER PATTERN...SENDING TEMPERATURES HIGHER INTO THE MID 90S
AND POSSIBLY EVEN UPPER 90S FOR SOME AREAS OVER THE WEEKEND. SOME
DIURNALLY DRIVEN CONVECTION CANNOT BE COMPLETELY RULED OUT BUT IT
WILL BE ISOLATED AT BEST WITH SEA BREEZE ACTIVITY ACROSS MAINLY
OUR SRN ZONES.
RELIEF FROM THE LATE SUMMER HEAT WILL LIKELY HAVE TO WAIT UNTIL
THURSDAY OF NEXT WEEK WITH AN ADVANCING COLD FRONT. THIS WILL ALSO
PROVIDE OUR NEXT BEST CHANCE AT SEEING WIDESPREAD SHWRS AND TSTMS
ACROSS THE REGION. EXPECT NOTICEABLY COOLER AND DRIER AIR IN THE
WAKE OF THIS FRONT...WITH TEMPERATURES LIKELY A FEW DEGREES BELOW
NORMAL BY THE END OF NEXT WEEK. /19/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 94 73 95 74 / 30 20 20 10
MLU 96 72 96 73 / 30 20 20 10
DEQ 94 69 94 70 / 20 10 10 10
TXK 94 71 94 73 / 20 20 10 10
ELD 93 70 95 72 / 30 20 20 10
TYR 92 73 94 73 / 20 10 20 10
GGG 93 72 94 73 / 20 10 20 10
LFK 94 71 93 72 / 20 20 30 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
24/07/19
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1158 AM CDT WED SEP 2 2015
.AVIATION...
MID LVL CLOUD DECKS ACROSS THE AREA INHIBITING CUMULUS DEVELOPMENT
IN MOISTER AIR UNDERNEATH. CONVECTION THUS FAR TODAY HAS REMAINED
JUST OFFSHORE IN GULF AND NE MOVMT OF CELLS COULD POSSIBLY TRAJECT
TOWARDS KMLU LATER THIS AFTN...SO PLACED TSTM VCNTY AT THAT
TERMINAL BUT NONE ELSEWHERE. FOG AND LOW CLOUDS TONIGHT LIMITED IN
LACK OF SOUTHERLY FLOW OR RECENT FOG DEVELOPMENT ACROSS AREA...BUT
IF SO...KLFK WOULD BE MOST LIKELY TERMINAL TO SEE ANY TEMPO MVFR
CONDITIONS OVERNIGHT. LGT VRBL WINDS ACROSS AREA TO REMAIN UNTIL
AT LEAST 03/15Z WITH ONLY SE WINDS AROUND 5 KTS AFTER THAT./VII/.
&&
.PREV DISCUSSION... /ISSUED 1137 AM CDT WED SEP 2 2015/
UPDATE...
A FEW MINOR CHANGES TO AFTERNOON POPS/SKY AND HIGH TEMPERATURES.
DISCUSSION...
ADD 10 AT 10 CST RULE WITH OBS RANGING ALL THROUGH THE 80S. A
DENSE MID DECK IS WORKING OVER THE HEART OF THE ARKLATEX WITH LOW
80S AND LIGHT OR CALM SFC WINDS. RUSTON AND MONROE ARE IN THE
UPPER 80S WITH A GOOD DEAL MORE SUNSHINE THIS MORNING. OUR RADAR
HAS A CLEAN SWEEP AND WITH LIMITED HEATING AND THAT MAY BE
THROUGH THE LUNCH HOUR.
OUR SOUNDING SHOWED MOISTURE INTO THE MID LEVELS...BUT VERY DRY
ABOVE AN INVERSION AT 18KFT. IT IS LIKELY THAT THE NE FLOW ABOVE
THE INVERSION HAS WORKED DOWN A BIT LOOKING AT THE WATER VAPOR.
ANY THUNDERSTORMS TODAY WILL BE LOW TOPPED AND PERHAPS FEW AND FAR
BETWEEN. MIDDECK SHOWERS ARE MORE LIKELY UNTIL WE SEE BETTER
HEATING THIS AFTERNOON. THE VAPOR SHOWS THE DRY AIR SPREADING SE
FOR THE LAST FEW HOURS...BUT HAS SLOWED ITS MOTION. THERE IS A
LITTLE VORT WORKING UP ACROSS W LA IN OVER TOLEDO BEND COUNTRY.
THIS MAY HELP WITH SOME CHANCE POPS FOR I-20 CORRIDOR LATER WITH
MORE HEATING AS THE MID DECK MOVES FARTHER NW.
THE HRRR SHOWS DECENT COVERAGE AND IS WHY WE LEFT CHANCE POPS.
SLIGHT CHANCE MAY BE A MORE LIKELY EVENT IF THAT LITTLE VORT FAILS
TO SPREAD DEEPER TROPICAL MOISTURE BACK INTO THAT DRIER AIR. THE
CHANCE FOR RAIN STILL LOOKS TO DECLINE INTO THE NEXT FEW DAYS AS
THE MAIN GULF LOW MOVES EASTWARD...TAKING THE TROPICAL CONNECTION
OUT OF REACH. /24/
PREV DISCUSSION... /ISSUED 412 AM CDT WED SEP 2 2015/
DISCUSSION...
WATER VAPOR IMAGERY CONTINUES TO DEPICT A WEAK UPPER LEVEL LOW
NEAR GALVESTON BAY THIS MORNING WITH A SHEAR AXIS EXTENDING NWRD
ACROSS DEEP E TX...N LA...AND SE AR. MID AND HIGH CLOUDS CONTINUE
TO BLANKET THESE AREAS WHILE POINTS ALONG AND NORTH OF THE I-30
CORRIDOR ARE SKC. AS MOISTURE REMAINS QUITE ABUNDANT OVER THE SE
HALF OF THE REGION TODAY...EXPECT SHWRS AND TSTMS TO INCREASE AS
WE MOVE INTO THE AFTERNOON HOURS WITH THE ADDED INSTABILITY FROM
HEATING. USING PERSISTENCE AS A GUIDE...DO EXPECT CLOUD COVER TO
HOLD DOWN TEMPERATURES SLIGHTLY MUCH LIKE YESTERDAY WITH UPPER 80S
AND LOWER 90S EXPECTED.
RAIN CHANCES WILL BEGIN TO DROP OFF AS WE HEAD INTO LATE WEEK AND
THE LABOR DAY WEEKEND AS UPPER RIDGING BECOMES MORE INFLUENTIAL IN
OUR WEATHER PATTERN...SENDING TEMPERATURES HIGHER INTO THE MID 90S
AND POSSIBLY EVEN UPPER 90S FOR SOME AREAS OVER THE WEEKEND. SOME
DIURNALLY DRIVEN CONVECTION CANNOT BE COMPLETELY RULED OUT BUT IT
WILL BE ISOLATED AT BEST WITH SEA BREEZE ACTIVITY ACROSS MAINLY
OUR SRN ZONES.
RELIEF FROM THE LATE SUMMER HEAT WILL LIKELY HAVE TO WAIT UNTIL
THURSDAY OF NEXT WEEK WITH AN ADVANCING COLD FRONT. THIS WILL ALSO
PROVIDE OUR NEXT BEST CHANCE AT SEEING WIDESPREAD SHWRS AND TSTMS
ACROSS THE REGION. EXPECT NOTICEABLY COOLER AND DRIER AIR IN THE
WAKE OF THIS FRONT...WITH TEMPERATURES LIKELY A FEW DEGREES BELOW
NORMAL BY THE END OF NEXT WEEK. /19/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 73 95 74 96 / 20 20 10 10
MLU 72 96 73 97 / 20 20 10 20
DEQ 69 94 70 94 / 10 10 10 10
TXK 71 94 73 96 / 20 10 10 10
ELD 70 95 72 95 / 20 20 10 10
TYR 73 94 73 95 / 10 20 10 10
GGG 72 94 73 94 / 10 20 10 10
LFK 71 93 72 93 / 20 30 20 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1137 AM CDT WED SEP 2 2015
.UPDATE...
A FEW MINOR CHANGES TO AFTERNOON POPS/SKY AND HIGH TEMPERATURES.
&&
.DISCUSSION...
ADD 10 AT 10 CST RULE WITH OBS RANGING ALL THROUGH THE 80S. A
DENSE MID DECK IS WORKING OVER THE HEART OF THE ARKLATEX WITH LOW
80S AND LIGHT OR CALM SFC WINDS. RUSTON AND MONROE ARE IN THE
UPPER 80S WITH A GOOD DEAL MORE SUNSHINE THIS MORNING. OUR RADAR
HAS A CLEAN SWEEP AND WITH LIMITED HEATING AND THAT MAY BE
THROUGH THE LUNCH HOUR.
OUR SOUNDING SHOWED MOISTURE INTO THE MID LEVELS...BUT VERY DRY
ABOVE AN INVERSION AT 18KFT. IT IS LIKELY THAT THE NE FLOW ABOVE
THE INVERSION HAS WORKED DOWN A BIT LOOKING AT THE WATER VAPOR.
ANY THUNDERSTORMS TODAY WILL BE LOW TOPPED AND PERHAPS FEW AND FAR
BETWEEN. MIDDECK SHOWERS ARE MORE LIKELY UNTIL WE SEE BETTER
HEATING THIS AFTERNOON. THE VAPOR SHOWS THE DRY AIR SPREADING SE
FOR THE LAST FEW HOURS...BUT HAS SLOWED ITS MOTION. THERE IS A
LITTLE VORT WORKING UP ACROSS W LA IN OVER TOLEDO BEND COUNTRY.
THIS MAY HELP WITH SOME CHANCE POPS FOR I-20 CORRIDOR LATER WITH
MORE HEATING AS THE MID DECK MOVES FARTHER NW.
THE HRRR SHOWS DECENT COVERAGE AND IS WHY WE LEFT CHANCE POPS.
SLIGHT CHANCE MAY BE A MORE LIKELY EVENT IF THAT LITTLE VORT FAILS
TO SPREAD DEEPER TROPICAL MOISTURE BACK INTO THAT DRIER AIR. THE
CHANCE FOR RAIN STILL LOOKS TO DECLINE INTO THE NEXT FEW DAYS AS
THE MAIN GULF LOW MOVES EASTWARD...TAKING THE TROPICAL CONNECTION
OUT OF REACH. /24/
&&
.PREV DISCUSSION... /ISSUED 654 AM CDT WED SEP 2 2015/
AVIATION...
FOR THE 02/12Z TAFS...PATCHY -DZ/-RA WILL AFFECT PORTIONS OF N
CNTRL LA EARLY IN THE TAF PERIOD MAINLY S OF I-20 AND E OF I-49.
ADDITIONAL ISOLATED TO WIDELY SCATTERED CONVECTION SHOULD AROUND
MIDDAY IN ASSOCIATION WITH AN UPPER TROUGH NEAR GALVESTON BAY.
SHWRS/TSTMS SHOULD LARGELY DISSIPATE BY 03/01Z. VFR CONDITIONS
SHOULD GENERALLY PREVAIL WITH THE EXCEPTION OF PATCHY FOG AT
KELD...WHICH SHOULD DISSIPATE BY 02/15Z...AND ANOTHER ROUND OF
PATCHY FOG WHICH MAY AFFECT KLFK NEAR THE END OF THE TAF PERIOD.
/09/
PREV DISCUSSION... /ISSUED 412 AM CDT WED SEP 2 2015/
DISCUSSION...
WATER VAPOR IMAGERY CONTINUES TO DEPICT A WEAK UPPER LEVEL LOW
NEAR GALVESTON BAY THIS MORNING WITH A SHEAR AXIS EXTENDING NWRD
ACROSS DEEP E TX...N LA...AND SE AR. MID AND HIGH CLOUDS CONTINUE
TO BLANKET THESE AREAS WHILE POINTS ALONG AND NORTH OF THE I-30
CORRIDOR ARE SKC. AS MOISTURE REMAINS QUITE ABUNDANT OVER THE SE
HALF OF THE REGION TODAY...EXPECT SHWRS AND TSTMS TO INCREASE AS
WE MOVE INTO THE AFTERNOON HOURS WITH THE ADDED INSTABILITY FROM
HEATING. USING PERSISTENCE AS A GUIDE...DO EXPECT CLOUD COVER TO
HOLD DOWN TEMPERATURES SLIGHTLY MUCH LIKE YESTERDAY WITH UPPER 80S
AND LOWER 90S EXPECTED.
RAIN CHANCES WILL BEGIN TO DROP OFF AS WE HEAD INTO LATE WEEK AND
THE LABOR DAY WEEKEND AS UPPER RIDGING BECOMES MORE INFLUENTIAL IN
OUR WEATHER PATTERN...SENDING TEMPERATURES HIGHER INTO THE MID 90S
AND POSSIBLY EVEN UPPER 90S FOR SOME AREAS OVER THE WEEKEND. SOME
DIURNALLY DRIVEN CONVECTION CANNOT BE COMPLETELY RULED OUT BUT IT
WILL BE ISOLATED AT BEST WITH SEA BREEZE ACTIVITY ACROSS MAINLY
OUR SRN ZONES.
RELIEF FROM THE LATE SUMMER HEAT WILL LIKELY HAVE TO WAIT UNTIL
THURSDAY OF NEXT WEEK WITH AN ADVANCING COLD FRONT. THIS WILL ALSO
PROVIDE OUR NEXT BEST CHANCE AT SEEING WIDESPREAD SHWRS AND TSTMS
ACROSS THE REGION. EXPECT NOTICEABLY COOLER AND DRIER AIR IN THE
WAKE OF THIS FRONT...WITH TEMPERATURES LIKELY A FEW DEGREES BELOW
NORMAL BY THE END OF NEXT WEEK. /19/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 91 73 95 74 / 30 20 20 10
MLU 94 72 96 73 / 30 20 20 10
DEQ 93 69 94 70 / 20 10 10 10
TXK 92 71 94 73 / 20 20 10 10
ELD 92 70 95 72 / 30 20 20 10
TYR 92 73 94 73 / 20 10 20 10
GGG 92 72 94 73 / 20 10 20 10
LFK 94 71 93 72 / 40 20 30 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
24/09/19
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
322 PM CDT WED SEP 2 2015
.SYNOPSIS...
ISSUED AT 322 PM CDT WED SEP 2 2015
H5 ANALYSIS THIS MORNING HAD LOW PRESSURE OVER WEST
CENTRAL PORTIONS OF BRITISH COLUMBIA WITH A TROUGH EXTENDING TO THE
SOUTHWEST INTO THE NERN PACIFIC. SOUTH OF THE LOW 50 TO 60 METER HT
FALLS WERE NOTED OVER OREGON AND WASHINGTION STATE WITH A 50 KT JET
STREAK COLLOCATED WITH THE HT FALLS. EAST OF THE LOW...BROAD WEST
SOUTHWESTERLY FLOW EXTENDED ACROSS THE NRN TIER OF STATES AND SRN
CANADA. SOUTH OF THE LOW AND JET STREAK...TWO SHORTWAVES WERE
NOTED...ONE NEAR LAS VEGAS AND A SECOND OFF THE COAST OF SRN
CALIFORNIA. AT THE SURFACE...A TROUGH OF LOW PRESSURE EXTENDED FROM
NORTH CENTRAL NEBRASKA INTO SWRN KS THIS AFTERNOON. WINDS BEHIND
THIS FEATURE WERE FROM THE WEST AT UNDER 10 MPH...WHILE EAST OF THIS
FEATURE...WINDS WERE FROM THE SOUTH AT AROUND 10 MPH. TEMPERATURES
AS OF 3 PM CDT RANGED FROM 95 AT ONEILL...TO 100 AT VALENTINE.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 322 PM CDT WED SEP 2 2015
WEAK UPPER HEIGHT RISES ONGOING ACROSS THE AREA AS CENTRAL PLAINS
RIDGE BUILDS IN RESPONSE TO DEEPING TROUGH ACROSS THE PAC NW. THE
SFC REFLECTION TO THIS IS A WEAK SFC TROUGH ACROSS THE MIDDLE OF THE
WESTERN HALF OF NEB...THOUGH WINDS ARE LIGHT MOST LOCATIONS. MOST
NOTABLE DIFFERENCE ACROSS THE ARE ARE DEW POINT TEMPS WHICH HAVE
DROPPED INTO THE UPPER 40S FROM VTN TO OGA...WITH MID 60S HANGING ON
FROM BBW TO ONL AT THIS HOUR. LOW LEVEL MOISTURE NOT MIXING OUT AS
FAR EAST AS THE NAM SUGGESTED...AND FAR FROM WHAT THE GFS HAD WHICH
IS A KNOWN ISSUE WITH THE GFS. DRY LINE WILL RETREAT WWD AFTER
SUNSET UNDER MAINLY CLEAR SKIES. OPERATIONAL HRRR AND RAP DEVELOPING
A SMALL AREA OF CONVECTIVE PRECIP LATE THIS AFTERNOON AS WEAK
FORCING ALOFT OVERLAYS THE DRY LINE BOUNDARY. SHORT TERM FCST
SOUNDINGS FROM THE HRRR AND RAP SHOW PRONOUNCED INVERTED V PROFILE
WITH VERY LITTLE CAPE ABOVE THE LFC. HAVE NOT INCLUDED MENTION OF
PRECIP NOR QPF THIS EVENING WITH THE IDEA THAT DRY AIR ENTRAINMENT
WILL INHIBIT THE POTENTIAL FOR DEEP...MOIST CONVECTION SUFFICIENT
FOR PRECIP.
AS FLOW BECOMES MORE MERIDIONAL WITH THE DEEPENING UPPER TROUGH IN
THE NW...NEXT PV ANOMALY AND ASSOCIATED PUSH OF MID AND UPPER LEVEL
MOISTURE WILL ROTATE NWD OUT OF THE SWRN UNITED STATES. THIS SHOULD
ALLOW FOR MORE SHOWER AND THUNDERSTORM DEVELOPMENT OVER THE HIGHER
TERRAIN FURTHER WEST WHICH WILL MOVE INTO THE WESTERN PORTIONS OF
THE AREA BY LATE AFTERNOON THURSDAY. SOME LARGE SCALE HEIGHT FALLS
ASSOCIATED WITH THIS FEATURE WILL ALLOW FOR SLIGHT COOLING OF THE
UPPER LEVELS AND WHEN PAIRED WITH SOMEWHAT DEEPER MOISTURE WITH
SERLY SFC WINDS...WILL BE SUFFICIENT FOR POSITIVE CAPE ABOVE THE
LOWER LFC BY LATE IN THE DAY. WEAK SHEAR REMAINS HOWEVER SO ALTHOUGH
BETTER CHANCES EXIST FOR THUNDERSTORMS...LARGE SCALE ORGANIZATION
DOES NOT LOOK FAVORABLE THROUGH 00Z FRI. THE ADDED MID AND UPPER
LEVEL MOISTURE AND ASSOCIATED CLOUDS WITH CONVECTION IN SWRLY
FLOW...WHICH HAS ORIGINS IN THE TROPICS ACCORDING TO ANALYSIS OF
320K MIXING RATIO...WILL ALLOW SLIGHTLY COOLER MAX TEMPS FOR
THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 322 PM CDT WED SEP 2 2015
THURSDAY NIGHT THROUGH SATURDAY NIGHT...IN THE MID RANGE...THE MAIN
FORECASTING CHALLENGES ARE PRECIPITATION CHANCES THURSDAY NIGHT...AND
AGAIN ON FRIDAY NIGHT INTO SATURDAY. FOR THURSDAY
NIGHT...THUNDERSTORMS WILL BE ONGOING ACROSS SWRN NEBR AND NERN
COLORADO AT THE BEGINNING OF THE PERIOD. THIS ACTIVITY WILL MOVE
NORTHEAST INTO THE NIGHTTIME HOURS THANKS TO DECENT MID LEVEL
WAA...WHICH TRACKS FROM SOUTHWESTERN INTO NORTH CENTRAL NEBRASKA. IN
ADDITION...THE NOSE OF A H85 JET STREAK WILL TRACK FROM SOUTH
CENTRAL INTO EASTERN NEBRASKA OVERNIGHT...ADDING ADDTL SUPPORT FOR
PRECIPITATION. AS FOR CHANCES...DECIDED TO KEEP THESE ON THE LOWER
SIDE OF THE ENVELOP AS TIME SECTIONS ARE INDICATIVE OF A DECENT DRY
LAYER BELOW 10000 FT AGL WHICH WILL LIMIT COVERAGE AS WELL AS QPF/S.
ON FRIDAY...STORMS WILL LINGER INTO THE MORNING HOURS ACROSS NERN
PORTIONS OF THE FORECAST AREA. BY AFTERNOON...TRANQUIL WEATHER CONDS
ARE EXPECTED AS THE FORECAST AREA IS IN BETWEEN SYSTEMS. SLIGHTLY
DRIER AIR WILL PUSH INTO THE NORTHWESTERN CWA FRIDAY WITH A DRYLINE
EXTENDING FROM NORTH CENTRAL INTO SWRN NEBRASKA. UPPER LEVEL FORCING
WILL HOLD OFF UNTIL FRIDAY AFTERNOON...SO MOST LOCATIONS WILL SEE A
DRY FCST ON FRIDAY. PCPN CHANCES WILL BEGIN TO INCREASE FRIDAY
EVENING AS A STRONG UPPER LEVEL DISTURBANCE LIFTS ACROSS EASTERN
COLORADO...APPG WESTERN NEBRASKA FRIDAY EVENING. THE BEFORE
MENTIONED DRYLINE WILL RETREAT WEST DURING THE EVENING HRS. HOW FAR
WEST THIS RETREATS AND THE AMOUNT OF DEEP LAYER MOISTURE AVAILABLE
FRIDAY NIGHT IS SOMEWHAT IN DOUBT ATTM. THE GFS IS MUCH DRIER IN THE
WEST COMPARED TO THE NAM SOLN. IN FACT...LAYER PW/S ARE RUNNING
AROUND A HALF AN INCH DRIER IN THE GFS COMPARED TO THE NAM SOLN. NO
SURPRISE...THE GFS IS DRY WITH ITS QPF FIELD FRIDAY NIGHT AND THE
NAM DEVELOPS CONVECTION INVOF THE DRYLINE. INHERITED FCST HAD A
MENTION OF PCPN FRIDAY NIGHT...AND WITH THE GFS BEING TOO DRY IN ITS
LOWER LEVELS UPON INITIALIZATION THIS MORNING...LEANED TOWARD THE
WETTER NAM SOLN WHICH SEEMED TO DO BETTER WITH THE MOISTURE FIELD.
THAT BEING SAID...PRECIPITATION CHANCES IN THE 20 TO 30 PERCENT
RANGE SEEM PLAUSIBLE FOR NOW. THE THREAT FOR PCPN WILL LINGER INTO
SATURDAY IN THE NORTH DURING THE MORNING HOURS...THEN WITH POSSIBLE
DEVELOPMENT OVER EASTERN AND CENTRAL NEBRASKA SATURDAY AFTERNOON. AS
FOR DEVELOPMENT SATURDAY AFTERNOON...ONCE AGAIN...THE GFS SEEMS TOO
DRY WITH ITS MOISTURE FIELD AND CONTINUE TO LEAN TOWARD THE WETTER
NAM SOLN WHICH INITIATES A LINE OF CONVECTION ACROSS THE CENTRAL AND
EASTERN CWA SAT AFTN. DEEP LAYER WIND SHEAR FINALLY REACHES 30 TO 40
KTS SAT AFTN...SO WOULDN/T BE SURPRISED IF A STRONG TO SEVERE STORM
DEVELOPS SAT AFTN/EVE.
SUNDAY THROUGH WEDNESDAY...IN THE EXTENDED...A STRONG UPPER LEVEL
LOW WILL TRACK ACROSS THE NORTHERN ROCKIES INTO SOUTH CENTRAL CANADA
SUNDAY INTO MONDAY. ON SUNDAY...A PREFRONTAL TROUGH WILL PUSH
THROUGH MOST OF THE FORECAST AREA...FORCING LOW LEVEL MOISTURE INTO
CENTRAL AND EASTERN NEBRASKA. FOR THE BULK OF THE FORECAST
AREA...SUNDAY AND SUNDAY NIGHT WILL BE DRY...HOWEVER...LOCATIONS IN
THE FAR NORTHEASTERN CWA WILL SEE A SLIGHT CHANCE FOR RAIN SUNDAY
AFTERNOON/NIGHT. ON SUNDAY NIGHT...A STRONG COLD FRONT WILL PASS
THROUGH THE FORECAST AREA...AND FOR THE MOST PART...WILL BE A DRY
FROPA WITH THE EXCEPTION OF THE FAR EASTERN CWA WHERE SOME LIMITED
MOISTURE WILL REMAIN IN PLACE. THE FRONT WILL THEN STALL ACROSS FAR
SRN NEBRASKA MONDAY...THEN LIFT NORTH MONDAY NIGHT INTO TUESDAY AS A
SECOND UPPER LEVEL WAVE DEVELOPS OVER THE NRN ROCKIES. WITH THE
FRONTAL BOUNDARY DRAPED ACROSS THE FORECAST AREA TUESDAY INTO
WEDNESDAY...WENT AHEAD AND LEFT IN A MENTION OF PCPN. TEMPERATURES
BEHIND THE FRONT MONDAY...TUESDAY AND WEDNESDAY WILL GENERALLY BE IN
THE 70S TO LOWER 80S WHICH IS RIGHT AT SEASONAL FOR EARLY
SEPTEMBER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1224 PM CDT WED SEP 2 2015
VFR CONDITIONS THROUGH THE PERIOD. ONLY CHALLENGE TO THE AVIATION
FORECAST WILL BE WEAK CONVECTION SUGGESTED TO DEVELOP BY SOME
MODELS IN ASSOCIATION WITH THE DRY LINE WHICH MIXES TO A LINE
FROM NEAR ONL SWWD TO NEAR CURTIS IN FRONTIER COUNTY...DEPENDING
ON THE MODEL. FCST SOUNDINGS SUGGEST VERY LITTLE POSITIVE AREA
FOR PARCELS DUE TO WARM TEMPS ALOFT. DRY LINE GRADIENT IN SRN NEB
IS NOT AS TIGHT AS FURTHER NORTH SUGGESTING ONLY WEAK POTENTIAL
FOR UPWARD MOTION ALONG THE BOUNDRY. WITH INVERTED V TYPE SOUNDING
PROFILES FCST BY THE MODELS...WOULD EXPECT A FEW CU/TCU
ORIGINATING AT AROUND 10K FT OR ABOVE BY LATE AFTERNOON ASSOCIATED
WITH THE AFOREMENTIONED BOUNDARY. WILL NOT MENTION ANY PRECIP
HOWEVER BECAUSE DRY AIR ENTRAINMENT SHOULD BE TOO DETRIMENTAL FOR
ANY CONVECTION TO REACH THAT STAGE. SOME OF THE CAMS DO SUGGEST AN
HOUR OR TWO OF REFLECTIVITY ASSOCIATED WITH WEAK CONVECTION...BUT
AS OF NOW THERE IS NOT ENOUGH CONFIDENCE TO MENTION. THIS WILL BE
MONITORED HOWEVER THROUGH THE AFTERNOON AS NEW HIGH RES FCSTS
BECOME AVAILABLE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CLB
SHORT TERM...JWS
LONG TERM...CLB
AVIATION...JWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
145 PM EDT WED SEP 2 2015
.SYNOPSIS...A DISTURBANCE WILL DROP SOUTHEAST THROUGH THE AREA
TONIGHT THROUGH EARLY THURSDAY...BUT OTHERWISE DEEP HIGH PRESSURE
WILL HOLD OVER THE REGION THROUGH FRIDAY. A COLD FRONT WILL MOVE
SOUTHWARD THROUGH THE AREA LATE FRIDAY INTO SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM WEDNESDAY...
PLENTY OF SUNSHINE THIS MORNING ALTHOUGH IT`S BEING FILTERED
SOMEWHAT BY AREAS OF THIN MID-HIGH CLOUDS BLOWN OFF OF CONVECTION
OVER AND SOUTH OF THE LOWER MISS VALLEY. THE POTENT MID LEVEL WAVE
WE`VE BEEN WATCHING FOR THE LAST FEW DAYS OVER CENTRAL INDIANA IS
NOTED THIS MORNING OVER SE OHIO IS ON TRACK TO DROP SE INTO AND
THROUGH THE AREA LATER TODAY THROUGH TONIGHT. THE TIMING INDICATED
BY THE SPC SSEO / NSSL WRF / 3KM NAM CONUS NEST / NCAR ENSEMBLE
NEIGHBORHOOD PROBABILITIES ARE FAIRLY CLOSE TO THE EXISTING
FORECAST... BRINGING GOOD COVERAGE INTO THE EXTREME NORTHERN CWA
AFTER 19Z OR 20Z... THEN DROPPING TO THE SSE PEAKING IN COVERAGE
AROUND 00Z... THEN MOVING INTO THE SRN/SE CWA WHILE CONTINUING TO
WEAKEN BEFORE DISSIPATING AROUND OR SOON AFTER 06Z. HAVE MADE MINOR
TIMING DIFFERENCES AND HAVE INCREASED INITIAL COVERAGE IN THE 21Z-
03Z TIME FRAME ACROSS THE NORTH. HAVE ALSO ADDED IN LOW CHANCE POPS
IN THE YADKIN VALLEY LATE THIS AFTERNOON AS THE HRRR AND NSSL WRF
DEPICT MOUNTAIN CONVECTION DRIFTING INTO THE SW AND EXTREME WRN CWA
LATE. MODELS CONTINUE TO VARY ON INSTABILITY POTENTIAL WITH THE NAM
(AND IT`S SLIGHTLY HIGHER SURFACE DEWPOINTS) SHOWING MUCAPE VALUES
NEARLY A MAGNITUDE GREATER THAN THE GFS. DEEP LAYER SHEAR REMAINS
MARGINAL AT JUST 20-25 KTS... SO EITHER WAY DON`T EXPECT A GREAT
SEVERE THREAT... ALTHOUGH A FEW STORMS COULD GET STRONG GIVEN THE
DYNAMIC CONTRIBUTION FROM DPVA. THICKNESSES AND HRRR/GRIDDED LAMP/
LOCAL WRF GUIDANCE SUPPORT HIGHS OF 90-94. -GIH
ISOLATED-SCATTERED CONVECTION WILL SLOWLY WANE TONIGHT AS THE LOW
LEVEL AIR MASS UNDERGOES ITS NORMAL NOCTURNAL STABILIZATION. BULK OF
CONVECTION WILL DISSIPATE PRIOR TO 06Z THOUGH POTENTIAL FOR A FEW
SHOWERS TO PERSIST IN THE COASTAL PLAIN UP TO SUNRISE. MIN TEMPS 67-
73. -WSS
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 258 AM WEDNESDAY...
WEAK SUBSIDENCE BEHIND THE DEPARTING DISTURBANCE SHOULD INHIBIT
CONVECTIVE REDEVELOPMENT THURSDAY MORNING. HEATING OF THE AIR MASS
OVER CENTRAL NC SHOULD TRIGGER ISOLATED CONVECTION ABOUT ANYWHERE IN
THE MID-LATE AFTERNOON HOURS. ANOTHER UPPER DISTURBANCE...THOUGH
WEAKER THAN THE SYSTEM EXPECTED TONIGHT...WILL APPROACH FROM THE NW
LATE IN THE DAY AND CROSS CENTRAL NC THURSDAY NIGHT. THIS SYSTEM MAY
PROVIDE ENOUGH LIFT TO INITIATE/SUSTAIN A SHOWER OR TWO BUT FEEL
THAT MOST PLACES WILL REMAIN DRY THURSDAY NIGHT. MAX TEMPS THURSDAY
SHOULD BE COMPARABLE TO DAY...90-95 DEGREES...WITH MIN TEMPS THU
NIGHT 67-72.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 305 AM WEDNESDAY...
FRIDAY THROUGH SATURDAY NIGHT: A BACKDOOR COLD FRONT WILL SINK
SOUTHWARD THROUGH THE AREA ON FRIDAY INTO FRIDAY EVENING AS ANOTHER
WEAK IMPULSE IN THE NORTH-NORTHWEST TO NORTHWESTERLY MID LEVEL FLOW
MOVES ACROSS THE AREA. THIS WILL TRIGGER AT LEAST ISOLATED TO
SCATTERED SHOWERS AND SOME STORMS FRIDAY AFTERNOON INTO THE EVENING.
OVERALL DEEP FLOW CONTINUES TO BE QUITE WEAK. GIVEN THIS AND RATHER
WEAK TO MODEST INSTABILITY EXPECT LITTLE IN THE WAY OF A SEVERE
THREAT... WITH THE ONLY LIMITED THREAT FROM LOCALIZED.... MAINLY
URBAN... FLOODING AS PW/S ARE EXPECTED TO BE AROUND 1.75" OR SO ON
FRIDAY. HIGH TEMPS FRIDAY IN ADVANCE OF THE FRONT ARE EXPECTED TO
REACH INTO THE UPPER 80S TO LOWER 90S. SURFACE HIGH PRESSURE WILL
BUILD INTO THE AREA FROM THE NORTH/NORTHEAST ON FRIDAY NIGHT INTO
SATURDAY. HOWEVER... WE WILL LIKELY SEE SOME LINGERING PRECIP
CHANCES AS A WEAK MID LEVEL LOW DEVELOPS JUST TO THE SOUTH OF THE
AREA. THUS... EXPECT LOW POPS (SLIGHT CHANCE) IN THE NORTHEAST...
WITH THE HIGHEST POPS (CHANCE) IN THE SOUTHWEST. GIVEN NORTHEAST TO
EASTERLY LOW LEVEL FLOW... WE WILL LIKELY START THE DAY WITH A GOOD
BIT OF CLOUD COVER/LOW STRATUS. GIVEN THE COOLER AIR MASS FROM THE
NORTH AND EXPECTED CLOUD COVER... WILL GO WITH HIGHS ON SATURDAY IN
THE LOWER TO MID 80S (AND THIS MAY STILL BE TOO WARM IN SPOTS). LOWS
SATURDAY MORNING ARE EXPECTED TO BE IN THE UPPER 60S AND IN THE MID
TO UPPER 60S SUNDAY MORNING.
SUNDAY THROUGH TUESDAY: THE WEAK MID LEVEL LOW WILL CONTINUE TO
LINGER ACROSS THE SOUTHEAST U.S. DURING THIS TIMEFRAME WHILE SLOWLY
SINKING SOUTHWESTWARD... YET STILL EXTENDING INTO OUR AREA... ALONG
WITH AN INVERTED SURFACE TROUGH NEAR THE COAST TO EASTERN PORTIONS
OF OUR AREA. THIS WILL GENERALLY RESULT IN THE BEST CHANCES FOR
PRECIP TO THE SOUTH OF OUR AREA... BUT WE COULD SEE SOME ISOLATED TO
SCATTERED SHOWERS AND STORMS EACH DAY (MAINLY DIURNAL IN NATURE) AND
GENERALLY ACROSS EASTERN AND SOUTHEASTERN PORTIONS OF CENTRAL NC.
HIGHS WILL REMAIN IN THE 80S... COOLEST ON SUNDAY... WITH LOWS IN
THE 60S.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 145 PM WEDNESDAY...
HIGH CONFIDENCE IN VFR CONDITIONS HOLDING THROUGH MID AFTERNOON
THU... ALTHOUGH THERE WILL BE ONE BRIEF PERIOD OF EXCEPTION. THE
PASSAGE OF AN UPPER LEVEL DISTURBANCE FROM NW TO SE THROUGH THE
REGION LATE TODAY THROUGH THIS EVENING WILL BRING SCATTERED
STORMS... MOST LIKELY TO AFFECT RWI AND PERHAPS RDU... WITH INT/GSO
SEEING A SLIGHTLY LOWER CHANCE OF STORMS AND FAY SEEING THE LEAST
CHANCE. THE PRIMARY WINDOW OF STORM POTENTIAL WILL BE 21Z-01Z AT
INT/GSO/RDU/RWI. A SHORT PERIOD OF GUSTY WINDS AND MVFR TO IFR
CONDITIONS CAN BE EXPECTED IN AND NEAR ANY STORMS... ALTHOUGH
COVERAGE WILL BE SMALL AND DURATION LESS THAN AN HOUR AT ANY GIVEN
LOCATION. OTHERWISE... ANY CIGS ARE LIKELY TO BE ABOVE 6K FT AGL.
LIGHT AND VARIABLE SURFACE WINDS WILL BECOME PREDOMINANTLY FROM THE
NE OR NORTH TONIGHT BUT REMAIN LIGHT THROUGH THU.
LOOKING BEYOND 18Z THU... VFR CONDITIONS LIKELY TO HOLD. THE CHANCE
OF SHOWERS AND STORMS INCREASES LATE FRI INTO FRI NIGHT IN
ASSOCIATION WITH A COLD FRONT PASSAGE... FOLLOWED BY A LOWER CHANCE
SAT AFTERNOON. SUB-VFR LOW CLOUDS AND FOG POSSIBLE LATE FRI NIGHT /
EARLY SAT MORNING... AND AGAIN LATE SAT NIGHT / EARLY SUN MORNING
WITH A LOW LEVEL FLOW FROM THE EAST OR NE BEHIND THE FRONT DRAWING
ATLANTIC MOISTURE INTO THE AREA. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/WSS
SHORT TERM...WSS
LONG TERM...BSD
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
451 PM CDT WED SEP 2 2015
.UPDATE...
ISSUED AT 441 PM CDT WED SEP 2 2015
WILL NEED TO DO A FORECAST UPDATE TO ACCOUNT FOR SHOWERS MOVING
FROM THE MILES CITY TO GLENDIVE AREA OF MONTANA TOWARD THE NORTH
DAKOTA BORDER. THE HRRR IS HANDLING THE PRECIPITATION THE BEST AS
COMPARED TO OTHER HI RES SHORT TERM MODELS. THE HRRR HAS THE
SHOWERS DEPICTED...AND BRINGS THEM INTO NORTH DAKOTA...EVEN INTO
THE CENTRAL PART OF THE STATE LATER.
KMLS ASOS HAD A WIND GUST OF 52 KNOTS...60 MPH...HOWEVER...THE
STATION REPORTED NO THUNDER AND THE LIGHTNING NETWORK SHOWED NO
LIGHTNING. SO...IT WAS A SHOWER THAT MIXED DOWN HIGHER WIND AND
LIKELY EVAPORATION ADDED TO THE DOWNWARD TRANSPORT. DOWNDRAFT CAPE
IS ANALYZED 1700-1800 UNITS ACROSS WESTERN NORTH DAKOTA.
WILL ADD POPS TO THE WEST AND MAY NEED TO BRING THEM INTO THE
CENTRAL PART OF THE STATE ON A LATER UPDATE. WILL THE ACTIVITY
HOLD TOGETHER AS DEPICTED BY THE HRRR...IS THE QUESTION.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 330 PM CDT WED SEP 2 2015
MAIN CONCERNS THIS PERIOD WILL BE SOME PATCHY FOG TONIGHT...
AND TEMPERATURES AND SOME SLIGHT CHANCES FOR THUNDERSTORMS ALONG
A SLOWLY MOVING FRONTAL BOUNDARY ACROSS THE NORTHWEST ON THURSDAY.
TONIGHT...THE H500 FLOW REMAINS ORIENTED SOUTHWEST TO NORTHEAST.
EXPECT THE COLD FRONTAL BOUNDARY WHICH IS ALIGNED WITH THE FLOW
ALOFT TO ONLY MOVE SLOWLY EAST TONIGHT AND THURSDAY. THIS WILL
GIVE THE REGION ANOTHER OPPORTUNITY FOR VERY WARM TEMPERATURES
THURSDAY ALONG AND AHEAD OF THE FRONT. HIGHS CENTRAL SECTIONS WILL
BE CLOSE TO 100. RELATIVELY COOLER AIR...ALTHOUGH STILL IN THE
MID 80S...WILL MOVE INTO THE NORTHWEST. LOW LEVEL MOISTURE
POOLING ALONG THE JAMES RIVER VALLEY TONIGHT WILL FAVOR MUGGY
CONDITIONS AND SOME PATCHY FOG TONIGHT WITH DEWPOINTS AROUND 70.
ON THURSDAY THE HEAT INDEX VALUES WILL RISE TO NEAR 100 ACROSS THE
JAMES RIVER VALLEY BY AFTERNOON.
THE NAM/GFS BOTH DEVELOP SOME WEAK CONVECTION ALONG THE FRONTAL
BOUNDARY THURSDAY. THE WRF MODEL DOES TOO BUT IN THE AFTERNOON.
WILL ADD ISOLATED THUNDERSTORMS FAR WEST INTO THE NORTH CENTRAL
THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 PM CDT WED SEP 2 2015
A SIGNIFICANT PATTERN CHANGE WILL IMPACT THE NORTHERN PLAINS FOR
THE UPCOMING HOLIDAY WEEKEND...WITH COOLER AND WETTER CONDITIONS.
STRONG UPPER LEVEL LOW DROPPING INTO THE PACIFIC NORTHWEST TODAY
WILL BECOME AN OPEN WAVE AND DEEPEN OVER THE WEST COAST THROUGH
SATURDAY. BY THURSDAY NIGHT EMBEDDED S/WV IMPULSES WILL BEGIN TO
APPROACH THE REGION...AND WHEN COUPLED WITH A SLOW MOVING SFC
BOUNDARY WILL RESULT IN CHANCES FOR SHOWERS/THUNDERSTORMS WEST TO
EAST DURING THE NIGHT. A PARTICULARLY STRONG EMBEDDED WAVE WILL
LIFT NORTHEAST ACROSS THE DAKOTAS LATE THURSDAY NIGHT/FRIDAY
MORNING AND MAY BRING MODERATE TO HEAVY RAIN TO PORTIONS OF NORTH
CENTRAL AND EASTERN NORTH DAKOTA DURING THAT TIMEFRAME.
FRIDAY-SATURDAY THE WEST COAST UPPER TROUGH BEGINS TO MOVE FARTHER
INLAND AND WILL DIRECT A SERIES OF SHORTWAVE ENERGY IMPULSES ACROSS
THE NORTHERN PLAINS. THE EXPECTED INCREASE IN CLOUD COVER AND CAA
IN THE WAKE OF THE SFC FRONT WILL RESULT IN MUCH COOLER
TEMPERATURES...WITH HIGHS DROPPING INTO THE 70S MOST AREAS BY
SATURDAY. SATURDAY NIGHT INTO SUNDAY THE BASE OF THE UPPER TROUGH
LIFTS NORTHEASTWARD ACROSS THE ROCKIES AND INTO THE NORTHERN
PLAINS...REACHING FAR SOUTH CENTRAL CANADA SUNDAY NIGHT. THIS
TIME PERIOD (FRIDAY-SUNDAY) WILL SEE VERY GOOD CHANCES FOR SHOWERS
AND THUNDERSTORMS. HEAVIEST PRECIPITATION FORECAST ACROSS THE
NORTH. TOTAL RAINFALL THURSDAY NIGHT THROUGH SUNDAY IS FORECAST TO
RANGE FROM AROUND HALF AN INCH SOUTHWEST...TO NEAR 2 INCHES NORTH.
HEAVIER AMOUNTS VERY POSSIBLE WITH THUNDERSTORMS. INSTABILITY NOT
OVERLY IMPRESSIVE SO WHILE A FEW STRONGER STORMS MAY FORM...THE
OVERALL SEVERE THREAT WILL BE MINIMAL.
MUCH COOLER IN THE WAKE OF THE STORM SYSTEM MONDAY...WITH FORECAST
HIGHS MID 60S TO LOW 70S. A QUASI-ACTIVE UPPER LEVEL ZONAL FLOW
SETS UP EARLY TO MID NEXT. THIS IS A DEVIATION FROM PREVIOUS
MODELS SO UNCERTAINTY RATHER HIGH AT THIS POINT. STILL LOOKS LIKE
A SLOW MODERATION IN TEMPERATURES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 330 PM CDT WED SEP 2 2015
AT 3 PM CDT...LOW PRESSURE ACROSS MONTANA WAS BRINGING SOUTHERLY
FLOW INTO THE REGION. VFR CONDITIONS ARE EXPECTED THROUGH THE TAF
PERIOD. SOME PATCHY FOG IS POSSIBLE IN THE JAMES RIVER VALLEY
THURSDAY MORNING. AT THIS TIME KEPT VSBYS AT 5 MILES OR GREATER
KBIS-KJMS AFTER 12Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JPM
SHORT TERM...WAA
LONG TERM...NH
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
148 PM EDT WED SEP 2 2015
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH THE
END OF THE WEEK. UPPER LEVEL DISTURBANCES TRACKING THROUGH THE
RIDGING WILL RESULT IN WIDELY SCATTERED MAINLY DIURNAL SHOWERS
AND STORMS INTO FRIDAY. A WEAK BACKDOOR COLD FRONT WILL DROP
SOUTH THROUGH THE AREA BY THE END OF WEEK BRINGING SOMEWHAT DRIER
AND COOLER AIR FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1255 PM EDT WEDNESDAY...
OUR LATEST FORECAST WILL REFLECT A CHANGE UPWARD BY AN AVERAGE OF
TWO TO THREE DEGREES OF THE HIGH TEMPERATURES. SEVERAL LOCATIONS
ARE ALREADY WITHIN A DEGREE OR TWO OF THE EARLIER FORECAST HIGHS.
WITH AT LEAST FOUR HOURS OF ADDITIONAL HEATING AT A CONSERVATIVE
DEGREE PER HOUR...AN INCREASE IN THE FORECAST HIGHS ARE WARRANTED.
ANOTHER ADJUSTMENT HAS BEEN TO THE COVERAGE OF ISOLATED SHOWERS
ACROSS THE SOUTHERN HALF OF THE CREST OF THE BLUE RIDGE AND
ADJOINING FOOTHILLS FROM THIS POINT ONWARD. INITIATION COMMENCED
ABOUT AN HOUR OR TWO EARLIER THAN PREVIOUSLY PREDICTED. OUR
FORECAST WILL NOW REFLECT THIS COVERAGE AS ONGOING. NO OTHER
NOTABLE CHANGES AT THIS TIME.
AS OF 930 AM EDT WEDNESDAY...
EARLY MORNING FOG HAS DISSIPATED IN ALL BUT PARTS OF THE
GREENBRIER AND NEW RIVER VALLEY REGIONS. HOWEVER...BY 1100 AM...AT
VAST MAJORITY...IF NOT ALL...OF THIS FOG WILL HAVE DISSIPATED AS
WELL. PRECIPITATION COVERAGE ACROSS THE REGION CURRENTLY IS ZERO.
THERE WERE A FEW ISOLATED SHOWERS OVER BUCKINGHAM COUNTY AROUND
THE TOP THE HOUR..BUT THESE HAVE SINCE FADED. LATEST MESOSCALE
MODELS PAINTS VERY LITTLE IF ANY PRECIPITATION ACROSS THE
NORTHERN PARTS OF THE AREA THROUGH 17Z/1PM...AND THEN START
RAMPING UP THE COVERAGE AFTER THAT TIME. HAVE TWEAKED THE
PROBABILITY OF PRECIPITATION GRIDS AND THE WEATHER GRIDS TO BETTER
REFLECT THIS TREND. NO OTHER NOTABLE CHANGES AT THIS TIME.
AS OF 240 AM EDT WEDNESDAY...
OVERALL HOT AND HUMID WEATHER FOR EARLY SEPTEMBER TO PERSIST TODAY AS
SURFACE HIGH PRESSURE REMAINS IN PLACE ACROSS THE MOUNTAINS. HOWEVER
SHORTWAVE ENERGY IN THE FORM OF AN OPENING UPPER LOW ACROSS THE OHIO
VALLEY WILL RIDE SOUTHEAST THROUGH THE 5H RIDGE AND OVER THE NORTHERN
HALF OF THE AREA THIS AFTERNOON. THIS SHOULD RESULT IN BETTER LIFT
ESPCLY ALONG AND JUST SOUTH OF THE INTERSTATE 64 CORRIDOR EARLY ON AND
ACROSS THE EASTERN HALF THROUGH LATE IN THE DAY. LATEST GUIDANCE ALSO
SHOWING BETTER INSTABILITY WITH A LITTLE MORE COOLING ALOFT...BUT STILL
UNCERTAINTY WITH COVERAGE GIVEN OVERALL BROAD SUBSIDENCE IN PLACE UNDER
RATHER WARM 5H TEMPS. CURRENT SPC/RNK WRF SOLUTIONS ALONG WITH THE
LATEST HRRR REMAIN THE MOST WIDESPREAD WITH SHRA/TSRA NORTH HALF AND
ALONG THE BLUE RIDGE. THIS WHILE MOST OTHER SOLUTIONS INCLUDING
ENSEMBLES PRODUCING LESS INCLUDING ONLY WIDELY SCATTERED SHALLOW
CONVECTION MAINLY CONFINED FROM THE VIRGINIA HIGHLANDS EAST TO AROUND
KLYH FOR THE MOST PART. THEREFORE ALIGNED HIGHEST CHANCE POPS ACROSS
THE FAR NORTH WITH A PERIOD OF LOWER CHANCES SOUTH/EAST DURING MID/LATE
AFTERNOON AND ONLY ISOLATED COVERAGE FAR SW. GIVEN WEAK FLOW ALOFT NOT
EXPECTING MUCH OF A SEVERE THREAT BUT COULD SEE A BIT MORE CLUSTERING
OF SLOW MOVING CONVECTION RIGHT NEAR THE CORE OF THE UPPER WAVE LATE.
OTHERWISE LOOKING AT MAINLY PC WITH MID DECK EARLY...THEN MORE CU THIS
AFTERNOON WITH HIGHS AGAIN REACHING THE LOW 90S EAST AND WELL INTO THE
80S ELSEWHERE PENDING TIMING OF CONVECTIVE INITIATION.
IMPULSE PASSES THIS EVENING LEAVING THE REGION IN BETWEEN WAVES AND
UNDER SURFACE HIGH PRESSURE. THIS SHOULD ALLOW MOST CONVECTION TO FADE
BY MIDNIGHT GIVEN LOSS OF HEATING AND SOME OVERNIGHT CLEARING PER WEAK
NW FLOW ALOFT IN THE WAKE OF THE MID LEVEL SYSTEM. THUS KEEPING SOME
LOW END CHANCE POPS GOING MAINLY EAST THIS EVENING BEFORE TRENDING DRY
WITH FOG AGAIN OVERNIGHT. LOWS PERHAPS SLIGHTLY COOLER GIVEN SOME DROP
IN DEWPOINTS AND ESPCLY WHERE ANY COOLING EVENING RAINFALL OCCURS BUT
STILL MOSTLY LOW/MID 60S MOUNTAINS TO UPPER 60S EAST.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 415 AM EDT WEDNESDAY...
WEAK UPPER-LEVEL SHORT WAVE WILL BE DISSIPATING ACROSS NORTH
CAROLINA DRIFTING SLOWLY INTO THE SOUTHEAST STATES WHERE IT
APPEARS IT IS DESTINED TO BECOME A WEAK CUTOFF THAT WILL
RETROGRADE/LINGER ACROSS THE SOUTHEAST/MID-SOUTH INTO NEXT WEEK AS
A LARGE HIGH AMPLITUDE UPPER RIDGE CONTINUES TO BUILD FROM THE
SOUTH CENTRAL/CENTRAL U.S. INTO SOUTHEAST CANADA AND THE NORTHEAST
U.S. OVER THE TOP OF THE WEAK CUTOFF LOW. UPPER SUPPORT WILL BE
MINIMAL AT BEST WITH BEST DYNAMICS...WHAT THEY ARE...HAVING
DRIFTED SOUTH OF THE AREA. ANY CONVECTION WILL LARGELY BE THE
RESULT OF DIFFERENTIAL HEATING AND FOCUSED PRIMARILY ACROSS THE
WESTERN MOUNTAINS. REALLY CANNOT SUPPORT MUCH MORE THAN 30 POPS AT
BEST.
BY FRIDAY...A LARGE SURFACE HIGH DEVELOPING ACROSS THE NORTHEAST
U.S. UNDERNEATH THE MAMMOTH UPPER RIDGE WILL BEGIN TO PUSH A
BACKDOOR FRONT FROM THE MID-ATLANTIC SOUTHWESTWARD. UPPER DYNAMICS
ARE VERY WEAK...BUT A MARKED DEWPOINT GRADIENT WILL EXIST ALONG
THE SOUTHWESTWARD ADVANCING BOUNDARY AS VERY DRY AIR ADVECTS
SOUTHWEST INTO NORTHERN VA. THIS SHOULD BE SUFFICIENT TO SUPPORT
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS...WITH THE BEST
COVERAGE SHIFTING SOUTHWEST TOWARD EVENING. INSTABILITY IS QUITE
NOTABLE ACROSS THE REGION IN ADVANCE OF THIS BACKDOOR FRONT...SO
EVEN WITH WEAK DYNAMICS...WITH THE NOTED INSTABILITY AND PWATS IN
THE 1.5 TO 1.7 INCH RANGE...30-40 PERCENT POPS SEEMS REASONABLE.
FOR SATURDAY...THE BACKDOOR FRONT CONTINUES TO DRIFT SOUTHWEST AND
SHOULD BE LOCATED FROM CENTRAL WV THROUGH SOUTHWEST VA...NEAR THE
I-77 CORRIDOR...INTO CENTRAL NC. VERY DRY AIR IS NOTED ADVECTING
INTO THE REGION FROM THE NORTHEAST WITH DEWPOINTS DROPPING INTO
THE 50S AND PWATS FALLING TO NEAR 0.50 INCH ACROSS THE NORTHEAST
PART OF THE CWA. ANY CONVECTION SATURDAY SHOULD BE LIMITED TO THE
I-77 CORRIDOR AND POINTS WESTWARD...PRIMARILY DURING THE
AFTERNOON/EVENING.
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL THURSDAY AND FRIDAY
AHEAD OF THE BACKDOOR FRONT...WITH MAX TEMPS WELL INTO THE
80S...NEAR 90 ACROSS THE PIEDMONT. MIN TEMPS WILL HOLD MOSTLY IN
THE 60S TO EVEN NEAR 70 ACROSS THE PIEDMONT. THESE READINGS ARE
AROUND 5 AND 10 DEGREES ABOVE NORMAL...RESPECTIVELY. MOS GUIDANCE
HAS BEEN TRENDING TOO MUCH TOWARD CLIMATOLOGY...SO NEEDED TO NUDGE
UP MOST AREAS FROM 2-3 DEGREES TO BETTER MATCH WHAT HAS BEEN
OCCURRING RECENTLY.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 445 AM EDT WEDNESDAY...
THE FOCUS THROUGH THE PERIOD WILL BE ON THE AFOREMENTIONED WEAK
AND INCREASING BROAD UPPER LOW ANCHORED ACROSS THE SOUTHEAST/MID-
SOUTH PART OF THE U.S. OUR CWA WILL BE STUCK IN THE TRANSITION
ZONE BETWEEN THIS INCREASINGLY MOIST/UNSTABLE AIR MASS TO THE
SOUTH AND THE PERSISTING UPPER RIDGE AND ASSOCIATED
SUBSIDENCE/VERY DRY AND WARM AIR MASS ACROSS THE MID-ATLANTIC
REGION. SHOWER/THUNDERSTORM CHANCES WILL GRADUALLY CREEP NORTHWARD
THROUGH THE PERIOD...BUT LIKELY REMAIN CONFINED TO AREAS WEST OF
I-77 SUNDAY...THEN CREEP FURTHER NORTH TOWARD THE U.S. 460
CORRIDOR BY MONDAY AND MUCH OF THE CWA BY TUESDAY. THE BEST
CHANCES THROUGHOUT THE PERIOD WILL REMAIN ACROSS THE WESTERN NC
MOUNTAINS. THE MODELS HAVE CONTINUALLY DELAYED THE ARRIVAL OF A
FRONT TOWARD THE MID PART OF NEXT WEEK...AND WITH THE UPPER RIDGE
SANDWICHED IN BETWEEN THE LOW PRESSURE AREA TO THE SOUTH AND THE
STRONGER WESTERLIES ALONG THE CANADIAN BORDER...IT MAY BE SOME
TIME BEFORE IT ACTUALLY REACHES OUR AREA. HENCE...SUMMER APPEARS
DESTINED TO HANG ON MUCH OF NEXT WEEK.
MAX TEMPS SHOULD BE NEAR NORMAL AT THE BEGINNING OF THE
PERIOD...BUT PERHAPS STILL SLIGHTLY ABOVE NORMAL WEST OF I-77. MIN
TEMPS WILL REMAIN NEAR NORMAL TO SLIGHTLY ABOVE NORMAL FAR
SOUTHWEST. MAX AND MIN TEMPS WILL CREEP TO SLIGHTLY ABOVE NORMAL
LEVELS AGAIN AS WE MOVE INTO EARLY NEXT WEEK.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 135 PM EDT WEDNESDAY...
A WEAK UPPER WAVE WAS MAKING PROGRESS EASTWARD NEAR THE MASON-
DIXON LINE. THIS FEATURE...ALONG WITH DAYTIME HEATING...WAS
TRIGGERING SOME ISOLATED TO SCATTERED SHOWERS ACROSS MAINLY
NORTHERN PART OF OUR REGION. SO FAR...THUNDERSTORMS HAVE REMAINED
TO OUR NORTH...BUT CANNOT BE RULED OUT LATER THIS
AFTERNOON...ESPECIALLY ACROSS NORTHERN AND EASTERN PARTS OF THE
REGION HEADING INTO THE EVENING HOURS. MOST LOCATIONS WILL REMAIN
VISUAL FLIGHT RULES THROUGH THE EARLY EVENING. THE EXCEPTION WILL
BE ISOLATED...AND BRIEF AND ISOLATED SUB-VISUAL FLIGHT RULES
CONDITIONS UNDER ANY OF THE STRONGER RAIN SHAFTS OF THE STRONGER
SHOWERS AND STORMS.
OVERNIGHT...LOOK FOR A RETURN OF MOUNTAIN AND RIVER VALLEY
MIST AND FOG...ESPECIALLY FOR ANY LOCATIONS THAT RECEIVE
MEASURABLE PRECIPITATION THIS AFTERNOON AND EVENING. PATCHY
MARGINAL VISUAL FLIGHT RULES CEILINGS WILL ALSO BE POSSIBLE
ACROSS THE MOUNTAINS.
FOR THURSDAY...ANY SUB-VISUAL FLIGHT RULES CONDITIONS WILL IMPROVE
TO VISUAL FLIGHT RULES BY 14Z/10AM. SOME ISOLATED SHOWERS ARE
EXPECTED TO DEVELOP...ESPECIALLY OVER THE MOUNTAINS BY 16Z/NOON.
EXTENDED AVIATION DISCUSSION...
THE REGION WILL CONTINUE TO UNDER THE INFLUENCE OF A HOT AND HUMID
DAYTIME AIRMASS THROUGH AT LEAST FRIDAY. ANTICIPATE A CONTINUATION
OF ISOLATED TO SCATTERED AFTERNOON SHOWERS...AND A FEW
STORMS...THAT LINGER INTO THE EVENING BEFORE DISSIPATING. COVERAGE
WILL BE GREATER ON FRIDAY AS COMPARED TO THURSDAY WITH THE
APPROACH OF A BACKDOOR COLD FRONT.
DRIER AIR WILL START WORKING ITS WAY INTO THE AREA FOR THE
WEEKEND. LOOK FOR A TREND TOWARDS LESS COVERAGE OF
PRECIPITATION...ESPECIALLY ON SUNDAY. THIS DRIER PATTERN WILL
CONTINUE INTO MONDAY.
&&
.EQUIPMENT...
AS OF 400 PM EDT TUESDAY...
THE DEW POINT READING AT KJFZ...RICHLANDS VA AWOS...IS INCORRECT.
AT THIS TIME WE DO NOT KNOW WHEN THIS SENSOR WILL BE REPAIRED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...DS/JH
SHORT TERM...RAB
LONG TERM...AMS/RAB
AVIATION...DS
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1258 PM EDT WED SEP 2 2015
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH THE
END OF THE WEEK. UPPER LEVEL DISTURBANCES TRACKING THROUGH THE
RIDGING WILL RESULT IN WIDELY SCATTERED MAINLY DIURNAL SHOWERS
AND STORMS INTO FRIDAY. A WEAK BACKDOOR COLD FRONT WILL DROP
SOUTH THROUGH THE AREA BY THE END OF WEEK BRINGING SOMEWHAT DRIER
AND COOLER AIR FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1255 PM EDT WEDNESDAY...
OUR LATEST FORECAST WILL REFLECT A CHANGE UPWARD BY AN AVERAGE OF
TWO TO THREE DEGREES OF THE HIGH TEMPERATURES. SEVERAL LOCATIONS
ARE ALREADY WITHIN A DEGREE OR TWO OF THE EARLIER FORECAST HIGHS.
WITH AT LEAST FOUR HOURS OF ADDITIONAL HEATING AT A CONSERVATIVE
DEGREE PER HOUR...AN INCREASE IN THE FORECAST HIGHS ARE WARRANTED.
ANOTHER ADJUSTMENT HAS BEEN TO THE COVERAGE OF ISOLATED SHOWERS
ACROSS THE SOUTHERN HALF OF THE CREST OF THE BLUE RIDGE AND
ADJOINING FOOTHILLS FROM THIS POINT ONWARD. INITIATION COMMENCED
ABOUT AN HOUR OR TWO EARLIER THAN PREVIOUSLY PREDICTED. OUR
FORECAST WILL NOW REFLECT THIS COVERAGE AS ONGOING. NO OTHER
NOTABLE CHANGES AT THIS TIME.
AS OF 930 AM EDT WEDNESDAY...
EARLY MORNING FOG HAS DISSIPATED IN ALL BUT PARTS OF THE
GREENBRIER AND NEW RIVER VALLEY REGIONS. HOWEVER...BY 1100 AM...AT
VAST MAJORITY...IF NOT ALL...OF THIS FOG WILL HAVE DISSIPATED AS
WELL. PRECIPITATION COVERAGE ACROSS THE REGION CURRENTLY IS ZERO.
THERE WERE A FEW ISOLATED SHOWERS OVER BUCKINGHAM COUNTY AROUND
THE TOP THE HOUR..BUT THESE HAVE SINCE FADED. LATEST MESOSCALE
MODELS PAINTS VERY LITTLE IF ANY PRECIPITATION ACROSS THE
NORTHERN PARTS OF THE AREA THROUGH 17Z/1PM...AND THEN START
RAMPING UP THE COVERAGE AFTER THAT TIME. HAVE TWEAKED THE
PROBABILITY OF PRECIPITATION GRIDS AND THE WEATHER GRIDS TO BETTER
REFLECT THIS TREND. NO OTHER NOTABLE CHANGES AT THIS TIME.
AS OF 240 AM EDT WEDNESDAY...
OVERALL HOT AND HUMID WEATHER FOR EARLY SEPTEMBER TO PERSIST TODAY AS
SURFACE HIGH PRESSURE REMAINS IN PLACE ACROSS THE MOUNTAINS. HOWEVER
SHORTWAVE ENERGY IN THE FORM OF AN OPENING UPPER LOW ACROSS THE OHIO
VALLEY WILL RIDE SOUTHEAST THROUGH THE 5H RIDGE AND OVER THE NORTHERN
HALF OF THE AREA THIS AFTERNOON. THIS SHOULD RESULT IN BETTER LIFT
ESPCLY ALONG AND JUST SOUTH OF THE INTERSTATE 64 CORRIDOR EARLY ON AND
ACROSS THE EASTERN HALF THROUGH LATE IN THE DAY. LATEST GUIDANCE ALSO
SHOWING BETTER INSTABILITY WITH A LITTLE MORE COOLING ALOFT...BUT STILL
UNCERTAINTY WITH COVERAGE GIVEN OVERALL BROAD SUBSIDENCE IN PLACE UNDER
RATHER WARM 5H TEMPS. CURRENT SPC/RNK WRF SOLUTIONS ALONG WITH THE
LATEST HRRR REMAIN THE MOST WIDESPREAD WITH SHRA/TSRA NORTH HALF AND
ALONG THE BLUE RIDGE. THIS WHILE MOST OTHER SOLUTIONS INCLUDING
ENSEMBLES PRODUCING LESS INCLUDING ONLY WIDELY SCATTERED SHALLOW
CONVECTION MAINLY CONFINED FROM THE VIRGINIA HIGHLANDS EAST TO AROUND
KLYH FOR THE MOST PART. THEREFORE ALIGNED HIGHEST CHANCE POPS ACROSS
THE FAR NORTH WITH A PERIOD OF LOWER CHANCES SOUTH/EAST DURING MID/LATE
AFTERNOON AND ONLY ISOLATED COVERAGE FAR SW. GIVEN WEAK FLOW ALOFT NOT
EXPECTING MUCH OF A SEVERE THREAT BUT COULD SEE A BIT MORE CLUSTERING
OF SLOW MOVING CONVECTION RIGHT NEAR THE CORE OF THE UPPER WAVE LATE.
OTHERWISE LOOKING AT MAINLY PC WITH MID DECK EARLY...THEN MORE CU THIS
AFTERNOON WITH HIGHS AGAIN REACHING THE LOW 90S EAST AND WELL INTO THE
80S ELSEWHERE PENDING TIMING OF CONVECTIVE INITIATION.
IMPULSE PASSES THIS EVENING LEAVING THE REGION IN BETWEEN WAVES AND
UNDER SURFACE HIGH PRESSURE. THIS SHOULD ALLOW MOST CONVECTION TO FADE
BY MIDNIGHT GIVEN LOSS OF HEATING AND SOME OVERNIGHT CLEARING PER WEAK
NW FLOW ALOFT IN THE WAKE OF THE MID LEVEL SYSTEM. THUS KEEPING SOME
LOW END CHANCE POPS GOING MAINLY EAST THIS EVENING BEFORE TRENDING DRY
WITH FOG AGAIN OVERNIGHT. LOWS PERHAPS SLIGHTLY COOLER GIVEN SOME DROP
IN DEWPOINTS AND ESPCLY WHERE ANY COOLING EVENING RAINFALL OCCURS BUT
STILL MOSTLY LOW/MID 60S MOUNTAINS TO UPPER 60S EAST.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 415 AM EDT WEDNESDAY...
WEAK UPPER-LEVEL SHORT WAVE WILL BE DISSIPATING ACROSS NORTH
CAROLINA DRIFTING SLOWLY INTO THE SOUTHEAST STATES WHERE IT
APPEARS IT IS DESTINED TO BECOME A WEAK CUTOFF THAT WILL
RETROGRADE/LINGER ACROSS THE SOUTHEAST/MID-SOUTH INTO NEXT WEEK AS
A LARGE HIGH AMPLITUDE UPPER RIDGE CONTINUES TO BUILD FROM THE
SOUTH CENTRAL/CENTRAL U.S. INTO SOUTHEAST CANADA AND THE NORTHEAST
U.S. OVER THE TOP OF THE WEAK CUTOFF LOW. UPPER SUPPORT WILL BE
MINIMAL AT BEST WITH BEST DYNAMICS...WHAT THEY ARE...HAVING
DRIFTED SOUTH OF THE AREA. ANY CONVECTION WILL LARGELY BE THE
RESULT OF DIFFERENTIAL HEATING AND FOCUSED PRIMARILY ACROSS THE
WESTERN MOUNTAINS. REALLY CANNOT SUPPORT MUCH MORE THAN 30 POPS AT
BEST.
BY FRIDAY...A LARGE SURFACE HIGH DEVELOPING ACROSS THE NORTHEAST
U.S. UNDERNEATH THE MAMMOTH UPPER RIDGE WILL BEGIN TO PUSH A
BACKDOOR FRONT FROM THE MID-ATLANTIC SOUTHWESTWARD. UPPER DYNAMICS
ARE VERY WEAK...BUT A MARKED DEWPOINT GRADIENT WILL EXIST ALONG
THE SOUTHWESTWARD ADVANCING BOUNDARY AS VERY DRY AIR ADVECTS
SOUTHWEST INTO NORTHERN VA. THIS SHOULD BE SUFFICIENT TO SUPPORT
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS...WITH THE BEST
COVERAGE SHIFTING SOUTHWEST TOWARD EVENING. INSTABILITY IS QUITE
NOTABLE ACROSS THE REGION IN ADVANCE OF THIS BACKDOOR FRONT...SO
EVEN WITH WEAK DYNAMICS...WITH THE NOTED INSTABILITY AND PWATS IN
THE 1.5 TO 1.7 INCH RANGE...30-40 PERCENT POPS SEEMS REASONABLE.
FOR SATURDAY...THE BACKDOOR FRONT CONTINUES TO DRIFT SOUTHWEST AND
SHOULD BE LOCATED FROM CENTRAL WV THROUGH SOUTHWEST VA...NEAR THE
I-77 CORRIDOR...INTO CENTRAL NC. VERY DRY AIR IS NOTED ADVECTING
INTO THE REGION FROM THE NORTHEAST WITH DEWPOINTS DROPPING INTO
THE 50S AND PWATS FALLING TO NEAR 0.50 INCH ACROSS THE NORTHEAST
PART OF THE CWA. ANY CONVECTION SATURDAY SHOULD BE LIMITED TO THE
I-77 CORRIDOR AND POINTS WESTWARD...PRIMARILY DURING THE
AFTERNOON/EVENING.
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL THURSDAY AND FRIDAY
AHEAD OF THE BACKDOOR FRONT...WITH MAX TEMPS WELL INTO THE
80S...NEAR 90 ACROSS THE PIEDMONT. MIN TEMPS WILL HOLD MOSTLY IN
THE 60S TO EVEN NEAR 70 ACROSS THE PIEDMONT. THESE READINGS ARE
AROUND 5 AND 10 DEGREES ABOVE NORMAL...RESPECTIVELY. MOS GUIDANCE
HAS BEEN TRENDING TOO MUCH TOWARD CLIMATOLOGY...SO NEEDED TO NUDGE
UP MOST AREAS FROM 2-3 DEGREES TO BETTER MATCH WHAT HAS BEEN
OCCURRING RECENTLY.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 445 AM EDT WEDNESDAY...
THE FOCUS THROUGH THE PERIOD WILL BE ON THE AFOREMENTIONED WEAK
AND INCREASING BROAD UPPER LOW ANCHORED ACROSS THE SOUTHEAST/MID-
SOUTH PART OF THE U.S. OUR CWA WILL BE STUCK IN THE TRANSITION
ZONE BETWEEN THIS INCREASINGLY MOIST/UNSTABLE AIR MASS TO THE
SOUTH AND THE PERSISTING UPPER RIDGE AND ASSOCIATED
SUBSIDENCE/VERY DRY AND WARM AIR MASS ACROSS THE MID-ATLANTIC
REGION. SHOWER/THUNDERSTORM CHANCES WILL GRADUALLY CREEP NORTHWARD
THROUGH THE PERIOD...BUT LIKELY REMAIN CONFINED TO AREAS WEST OF
I-77 SUNDAY...THEN CREEP FURTHER NORTH TOWARD THE U.S. 460
CORRIDOR BY MONDAY AND MUCH OF THE CWA BY TUESDAY. THE BEST
CHANCES THROUGHOUT THE PERIOD WILL REMAIN ACROSS THE WESTERN NC
MOUNTAINS. THE MODELS HAVE CONTINUALLY DELAYED THE ARRIVAL OF A
FRONT TOWARD THE MID PART OF NEXT WEEK...AND WITH THE UPPER RIDGE
SANDWICHED IN BETWEEN THE LOW PRESSURE AREA TO THE SOUTH AND THE
STRONGER WESTERLIES ALONG THE CANADIAN BORDER...IT MAY BE SOME
TIME BEFORE IT ACTUALLY REACHES OUR AREA. HENCE...SUMMER APPEARS
DESTINED TO HANG ON MUCH OF NEXT WEEK.
MAX TEMPS SHOULD BE NEAR NORMAL AT THE BEGINNING OF THE
PERIOD...BUT PERHAPS STILL SLIGHTLY ABOVE NORMAL WEST OF I-77. MIN
TEMPS WILL REMAIN NEAR NORMAL TO SLIGHTLY ABOVE NORMAL FAR
SOUTHWEST. MAX AND MIN TEMPS WILL CREEP TO SLIGHTLY ABOVE NORMAL
LEVELS AGAIN AS WE MOVE INTO EARLY NEXT WEEK.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 640 AM EDT WEDNESDAY...
FOG AND STRATUS REMAIN SPOTTY ACROSS THE REGION EARLY THIS MORNING
WITH THE TYPICAL VALLEY LOCATIONS SUCH AS KLWB/KBCB SEEING IFR OR
WORSE ATTM. EXPECT COULD SEE A BRIEF REDUCTION IN VSBY AS WELL
AROUND KLYH/KDAN AS WELL DURING THE NEXT HOUR OR TWO BEFORE
HEATING HELPS DISSIPATE ANY RESIDUAL LOW LEVEL MOISTURE. OTHERWISE
WAVES OF MID/HIGH CLOUDS AHEAD OF THE UPPER SYSTEM TO THE NW THE
MAIN ASPECT ONCE ANY LOW CLOUDS BURN OFF WITH VFR EXPECTED AT ALL
LOCATIONS FROM MID MORNING ONWARD.
UPPER WAVE OVER THE OHIO VALLEY WILL SHIFT SLOWLY SOUTHEAST INTO
VIRGINIA THIS AFTERNOON WHILE SLOWLY WEAKENING. THIS WILL ALLOW
MORE INSTABILITY WITH STEEPER LAPSE RATES AND LIFT. SHOWERS AND
STORMS WILL BE MORE SCATTERED THIS AFTERNOON WITH BEST FORCING
ACROSS THE NORTHERN FOOTHILLS/PIEDMONT TO THE NEW RIVER VALLEY.
AS OF NOW WILL KEEP THE GOING VCTS AT KROA/KLYH AND KBCB AFTER
19-20ZZ/3-4PM...BUT THINK COVERAGE WILL BE LESS FURTHER WEST AND
OVER THE SOUTHEAST...SO ONLY GOING WITH A VCSH AT KLWB-KBLF WHILE
KEEPING MENTION OUT OF KDAN FOR NOW. OVERALL EXPECT VFR
CONDITIONS OUTSIDE ANY CONVECTION INTO THIS EVENING WITH CIGS OF
4-6KFT WITH TCU AND CB IN THE AFTERNOON.
EXTENDED AVIATION DISCUSSION...
THE FORECAST AREA WILL REMAIN IN A WEAKLY FORCED SYNOPTIC
ENVIRONMENT THROUGH THURSDAY...WITH CHANCES FOR DIURNAL
CONVECTION MAINLY FROM THE BLUE RIDGE WEST...AND SOME MVFR/IFR
FOG/STRATUS DEVELOPMENT AT NIGHT...ESPECIALLY AT KBCB AND KLWB. A
WEAK BACKDOOR COOL FRONT MAY ENHANCE THE CHANCES FOR SHOWERS AND
STORMS LATER FRIDAY BEFORE DRIER AIR ARRIVES FRIDAY NIGHT.
FOR SATURDAY INTO SUNDAY WILL SEE HIGH PRESSURE IN CONTROL THOUGH
THE POSITION OF THE HIGH OVER THE MID ATLANTIC MAY SLIDE MORE MVFR
CIGS OFF THE ATLANTIC INTO OUR EASTERN TAF LOCATIONS AT LEAST TO
START THE WEEKEND.
&&
.EQUIPMENT...
AS OF 400 PM EDT TUESDAY...
THE DEW POINT READING AT KJFZ...RICHLANDS VA AWOS...IS INCORRECT.
AT THIS TIME WE DO NOT KNOW WHEN THIS SENSOR WILL BE REPAIRED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...DS/JH
SHORT TERM...RAB
LONG TERM...AMS/RAB
AVIATION...JH/NF/WP
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1135 AM CDT WED SEP 2 2015
.UPDATE...THIS AFTERNOON
ISSUED AT 1134 AM CDT WED SEP 2 2015
WITH THE NORTHERN SHORT WAVE BECOMING THE MORE DOMINANT ONE THIS
MORNING AND A STRONG 750 TO 400 MB CAP COMING IN THE WAKE OF THE
SHORT WAVE...THE CHANCE OF SHOWERS AND THUNDERSTORMS SOUTH OF
INTERSTATE 94 WERE REMOVED FOR THIS AFTERNOON AND EVENING.
THIS WILL RESULT IN MORE SUNSHINE THAN ORIGINALLY ANTICIPATED...SO
RAISED THE HIGH TEMPERATURES ANYWHERE FROM 3 TO 5 DEGREES WHICH
INCREASED THE HEAT INDICES INTO THE LOWER TO MID 90S.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 300 AM CDT WED SEP 2 2015
DATA ANALYSIS THIS MORNING FEATURES A MID-LEVEL TROUGH/MCV MAKING
ITS WAY ACROSS SOUTH-CENTRAL MN/CENTRAL IA TOWARD THE UPPER
MISSISSIPPI RIVER VALLEY REGION. THERE HAS BEEN SOME EFFICIENT RAIN-
MAKERS EMBEDDED WITHIN THIS COMPLEX OF CONVECTION GIVEN HUMID/HIGHER
PRECIPITABLE WATER ENVIRONMENT. FEW HOURLY PRECIPITATION REPORTS
COMING IN FROM 3/4 TO JUST OVER AN INCH. OTHERWISE...MUGGY EARLY
MORNING ACROSS THE AREA WITH TEMPERATURES/DEW POINTS IN THE UPPER
60S TO THE MIDDLE 70S.
WILL BE WATCHING THE TROUGH/MCV CONTINUE MOVING ACROSS OUR AREA
TODAY. RAP SHOWING DECENT PUSH OF 850-700MB MOISTURE TRANSPORT
CONTINUING THROUGH 18Z. SO...EXPECTING THIS CONVECTIVE COMPLEX TO
HOLD TOGETHER THROUGH THIS MORNING WITH CHANCES FALLING OFF DURING
THE AFTERNOON FROM WEST TO EAST AS BETTER MOISTURE PUSHES EAST WITH
THE TROUGH. HIGHEST CONCENTRATION OF SHOWERS/STORMS LOOK TO BE NORTH
OF I-90 OR NOSE OF THE BETTER 850-700MB MOISTURE TRANSPORT. ALTHOUGH
SEVERE WEATHER IS NOT ANTICIPATED TO BE WIDESPREAD TODAY GIVEN LOW-
END BULK SHEAR FOR ORGANIZATION...COULD BE SOME SPORADIC HIGHER WIND
GUSTS MIXED IN WITH HEAVIER DOWNPOURS. PLAN ON MUGGY CONDITIONS
OTHERWISE WITH HIGHS IN THE 80S AND DEW POINTS STAYING IN THE UPPER
60S TO LOWER 70S. THIS WILL PUT HEAT INDICES IN THE 90-95 DEGREE
RANGE MAINLY SOUTH OF I-90.
LINGERING SHOWER/THUNDERSTORM CHANCES CONTINUE THROUGH TONIGHT AS
WANING 850-700MB MOISTURE TRANSPORT IMPINGES ON SURFACE TROUGH/WARM
FRONTAL BOUNDARY EAST OF THE MISSISSIPPI RIVER. LOOK FOR MUGGY
OVERNIGHT TEMPERATURES IN THE MIDDLE 60S TO NEAR 70.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 300 AM CDT WED SEP 2 2015
ISOLATED TO SCATTERED SHOWERS/THUNDERSTORMS STILL POSSIBLE ACROSS
CENTRAL WISCONSIN THURSDAY AS THIS AREA WILL BE ALONG THAT
AFOREMENTIONED SURFACE TROUGH/WARM FRONTAL BOUNDARY AND VERY WEAK
850MB MOISTURE TRANSPORT. OTHERWISE...ANOTHER MUGGY DAY ON TAP WITH
HIGHS IN THE 80S AND DEW POINTS HANGING IN THE UPPER 60S/LOWER 70S.
HEAT INDICES ARE EXPECTED TO TOP OFF IN THE 90-95 DEGREE RANGE.
FRIDAY APPEARS DRY BUT RAIN CHANCES INTO THE WEEKEND WILL HANG ON
DISTURBANCES EJECTING OUT OF MONSOONAL FLOW OVER THE SOUTHWEST.
MODELS SEEM TO BE HAVING A DIFFICULT TIME HANDLING THESE FEATURES IN
DETAIL...YIELDING LOW-END SHOWER/THUNDERSTORM CHANCES SATURDAY.
APPEARS LATEST ECMWF/GFS ARE CONVERGING ON SLIGHTLY FASTER TIMING ON
INCOMING MID-LEVEL TROUGH/SURFACE COLD FRONT FROM THE NORTHERN
PLAINS SUNDAY INTO MONDAY. APPEARS HIGHEST SHOWER/THUNDERSTORM
CHANCES WILL BE SUNDAY NIGHT WITH THE COLD FRONT POSSIBLY CLEARING
THE AREA BY AFTERNOON ON LABOR DAY. OTHERWISE...STILL LOOKING HOT
AND MUGGY SATURDAY AND SUNDAY WITH HIGHS WELL INTO THE 80S AND HEAT
INDICES IN THE UPPER 80S TO MIDDLE 90S.
TUESDAY WILL SEE A CHANCE OF SHOWERS AND STORMS ACROSS NORTHEAST IA
INTO FAR SOUTHWEST WI AS THE COLD FRONT STALLS OUT JUST SOUTH OF
THAT AREA. COOLER/DRIER AIR IS ON TAP OTHERWISE WITH HIGHS LOOKING
TO BE IN THE UPPER 60S ACROSS NORTHERN WI...TO THE LOWER/MIDDLE 70S
SOUTH OF I-90.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1134 AM CDT WED SEP 2 2015
SKIES WILL BE MOSTLY SUNNY THIS AFTERNOON AT THE TAF SITES THIS
AFTERNOON. DIURNAL HEATING WILL ALLOW THE SOUTH WINDS TO GUST INTO
THE 20 TO 25 KNOT RANGE. THESE WIND GUSTS WILL CONTINUE THROUGH
03/02Z.
THE SOUNDINGS OVERNIGHT DO NOT LOOK FAVORABLE FOR DENSE FOG AT
EITHER TAF SITES TONIGHT. HOWEVER THERE WILL STILL BE A
POSSIBILITY THAT FOG MAY STILL REDUCE VISIBILITIES TO 3 TO 5
STATUE MILES LATE BETWEEN 03.09Z AND 03.13Z. WHILE DENSE FOG DOES
NOT LOOK FAVORABLE FOR THE TAF SITES...IT DOES LOOK FAVORABLE FOR
CENTRAL AND NORTH CENTRAL WISCONSIN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BOYNE
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...BOYNE