Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/25/13
AREA FORECAST DISCUSSION
NWS MIAMI FL
922 PM EDT TUE SEP 24 2013
.UPDATE...
SMALL CLUSTERS OF CONVECTION REMAIN OVER THE COASTAL WATERS
ADJACENT TO BOTH COASTS BUT WITH THE LOSS OF DIURNAL HEATING AND
THE BULK OF THE UPPER DYNAMICS WELL NORTH, THE SOUTHERN PENINSULA
APPEARS LIKE IT WILL BE QUIET FOR THE REMAINDER OF TONIGHT. THIS
ALSO SUGGESTED BY THE SHORT TERM HIGH RESOLUTION MODELS. THUS,
HAVE LOWERED THE POPS FOR THE OVERNIGHT HOURS BUT MOISTURE ABOUNDS
AND ATMOSPHERE REMAINS WEAKLY UNSTABLE SO A FEW CONVECTIVE CELLS
CANNOT BE RULED OUT.
KOB
&&
.PREV DISCUSSION... /ISSUED 841 PM EDT TUE SEP 24 2013/
AVIATION...
SCATTERED LIGHT TO MODERATE SHOWERS WILL CONTINUE TO SPREAD ASHORE
ALONG THE GULF COAST AROUND AND OVER THE APF TERMINAL THROUGH THE
MID TO LATE EVENING HOURS. PERIODS OF SUB-VFR CONDITIONS WILL
REMAIN POSSIBLE THROUGH THIS TIME AS THESE SPREAD ASHORE. THE
LATEST HRRR MODEL RUN INDICATES THIS ACTIVITY TRENDING DOWN
THROUGH THE OVERNIGHT PERIOD. HOWEVER...SOUTHWEST FLOW AND PLENTY
OF MOISTURE AHEAD OF AN FRONTAL BOUNDARY WILL SUPPORT KEEPING THE
VCSH IN THE APF PACKAGE. FOR WEDNESDAY...THE WET CONDITIONS WILL
PERSIST WITH LIGHT TO MODERATE SOUTH-SOUTHWEST WINDS.
PREV DISCUSSION... /ISSUED 257 PM EDT TUE SEP 24 2013/
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
CONVECTION HAS BEEN MINIMAL TODAY FOR ALL BUT PALM BEACH
COUNTY...THOUGH GUIDANCE INDICATES THIS WILL PARTIALLY CHANGE LATE THIS
AFTERNOON. EXPECT THE MAJORITY OF ORGANIZED CONVECTION TO REMAIN
NORTH OF SOUTH FLORIDA...ALONG A WEAKENING STATIONARY
FRONT/SURFACE TROUGH DRAPED OVER CENTRAL FLORIDA. STILL...SOME
CELL CLUSTERS ARE EXPECTED TO SPREAD INTO GLADES AND HENDRY COUNTY
FROM THE WEST BY 4PM EDT...AND CONTINUED CONVECTIVE INITIATION IS
FORECAST FOR PALM BEACH COUNTY...LIKELY EXTENDING INTO BROWARD
COUNTY WITH TIME...WHERE CONVERGENCE IS BEING ENHANCED DUE TO SEA-
BREEZE BOUNDARY. ELSEWHERE...ONLY ISOLATED TO SCATTERED
CONVECTION IS EXPECTED. PLENTY OF INSTABILITY AND SOMEWHAT FAVORABLE LOW-
LEVEL SHEAR FOR ANY THUNDERSTORMS TO WORK WITH...SO SOME RISK OF
STRONG WIND GUSTS AND POSSIBLY A FUNNEL/WATERSPOUT. PWATS ARE
STILL VERY HIGH...SO ANY ACTIVITY IS GOING TO HAVE VERY HIGH
RAINFALL RATES AND THERE IS CONCERN FOR LOCALIZED URBAN FLOODING.
THE RISK LATER THIS EVENING IS THAT LARGE CONVECTIVE COMPLEX
BETWEEN RSW AND TBW /EXTENDING WESTWARD INTO THE GULF/ WILL HAVE
SUFFICIENT COOL POOL FOR SOUTHWARD MOVING BOUNDARIES...LEADING TO
MORE COVERAGE OF SHOWERS AND THUNDERSTORMS NORTH OF A NAPLES TO
PALM BEACH LINE. POPS ARE HIGHEST THIS REGION THIS
EVENING...THOUGH CONFIDENCE IS LOW FOR THIS TIMEFRAME. OTHERWISE...
CONVECTION SHOULD FOR THE MOST PART DIMINISH DIURNALLY.
LITTLE SUPPORT FOR THE SURFACE BOUNDARY TO MOVE SOUTHWARD OUT OF
CENTRAL FLORIDA THROUGH THE SHORT TERM. HOWEVER...THE FEATURE WILL
LIKELY DRIFT TOWARD/INTO SOUTH FLORIDA WEDNESDAY AND THURSDAY.
THEREFORE...RAIN CHANCES REMAIN HIGH AND RISK FOR HEAVY RAIN MAY
ACTUALLY INCREASE DURING THIS PERIOD AS THE REGION GETS CLOSER TO
THE MAXIMIZED MOISTURE CONVERGENCE. WINDS GRADUALLY VEER MORE
WESTERLY OVER THE PERIOD. LATEST GUIDANCE SUGGEST FRONT WILL NOT
MAKE SIGNIFICANT PROGRESS SOUTH OF PENINSULA UNTIL IT RECEIVES
REINFORCING PUSH OF DRY AIR FROM THE NORTH ON THE HEELS OF A MID-
LATITUDE UPPER-LEVEL TROUGH AT THE END OF THE WEEK.
LONG TERM...
THE FRONT WILL CONTINUE TO MOVE SOUTH INTO THE FLORIDA STRAITS
THIS WEEKEND...AS THE HIGH OVER THE SOUTHEASTERN UNITED STATES
CONTINUES TO STRENGTHEN. THIS WILL ALLOW FOR THE WINDS OVER SOUTH
FLORIDA TO BECOME NORTHERLY AND BREEZY BRINGING IN THE DRIER AIR
FROM THE NORTH. SO THE POPS THIS WEEKEND WILL BE IN THE SLIGHT
CHANCE...EXCEPT LOW END CHANCE OVER THE WEST COAST METRO AREAS.
THE PWAT VALUES WILL ALSO BE FALLING FROM THE 1.7 INCHES EARLY
THIS WEEKEND TO 1.3 INCHES BY LATE THIS WEEKEND WHICH IS 2
STANDARD DEVIATIONS BELOW NORMAL. SO WILL KEEP A SLIGHT CHANCE OF
STORMS IN FOR THE INTERIOR AND WEST COAST METRO AREAS ON
SATURDAY...BEFORE REMOVING THE THUNDER THREAT FOR ALL OF SOUTH
FLORIDA FOR SUNDAY.
THE HIGH WILL REMAIN OVER THE SOUTHEAST UNITED STATES EARLY NEXT
WEEK KEEPING THE STEERING FLOW IN A NORTHEAST DIRECTION. THIS WILL
KEEP THE DRY WEATHER IN PLACE ALONG WITH THE VERY LOW PWAT VALUES.
SO THE POPS WILL REMAIN IN THE SLIGHT CHANCE WITH NO THREAT OF
THUNDER FOR EARLY NEXT WEEK.
AVIATION...
CURRENT SHOWERS/THUNDERSTORMS ARE IN THE VICINITY OF TERMINAL KPBI
WHICH WILL LIKELY BE IMPACTED 18Z TO 19Z WITH PERIODS OF BRIEF MVFR
TO VERY BRIEF IFR CONDITIONS POSSIBLE WITH PASSING
SHOWERS/THUNDERSTORMS. FOR THE REMAINDER OF THE
TERMINALS...CONVECTION HAS BEEN SUPPRESSED THROUGH 18Z BUT COULD
INITIATE AT ANY MOMENT THROUGH ABOUT 00Z...SO VCTS ASSIGNED EAST
COAST TAF`S AT 18Z. FOR TERMINAL KAPF...LINE OF SHOWERS/THUNDERSTORMS
TO THE NORTHWEST OF FT. MYERS COULD TRIGGER CONVECTION WITH VCTS
ASSIGNED AT 18Z...WITH BRIEF MVFR TO VERY BRIEF IFR CONDITIONS
POSSIBLE WITH PASSING SHOWERS/THUNDERSTORMS.
60
MARINE...
NUMEROUS SHOWERS AND THUNDERSTORMS WILL PREVAIL OVER SOUTH FLORIDA
WATERS WEDNESDAY AND THURSDAYS. DESPITE LOCALLY MUCH GUSTIER WINDS
IN AND NEAR CONVECTION...SYNOPTIC WINDS WILL BE SOUTHWEST AT 10 TO
15 KTS WEDNESDAY...THEN WEST AND NORTHWEST ON THURSDAY AT SIMILAR SPEEDS.
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
841 PM EDT TUE SEP 24 2013
.AVIATION...
SCATTERED LIGHT TO MODERATE SHOWERS WILL CONTINUE TO SPREAD ASHORE
ALONG THE GULF COAST AROUND AND OVER THE APF TERMINAL THROUGH THE
MID TO LATE EVENING HOURS. PERIODS OF SUB-VFR CONDITIONS WILL
REMAIN POSSIBLE THROUGH THIS TIME AS THESE SPREAD ASHORE. THE
LATEST HRRR MODEL RUN INDICATES THIS ACTIVITY TRENDING DOWN
THROUGH THE OVERNIGHT PERIOD. HOWEVER...SOUTHWEST FLOW AND PLENTY
OF MOISTURE AHEAD OF AN FRONTAL BOUNDARY WILL SUPPORT KEEPING THE
VCSH IN THE APF PACKAGE. FOR WEDNESDAY...THE WET CONDITIONS WILL
PERSIST WITH LIGHT TO MODERATE SOUTH-SOUTHWEST WINDS.
&&
.PREV DISCUSSION... /ISSUED 257 PM EDT TUE SEP 24 2013/
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
CONVECTION HAS BEEN MINIMAL TODAY FOR ALL BUT PALM BEACH
COUNTY...THOUGH GUIDANCE INDICATES THIS WILL PARTIALLY CHANGE LATE THIS
AFTERNOON. EXPECT THE MAJORITY OF ORGANIZED CONVECTION TO REMAIN
NORTH OF SOUTH FLORIDA...ALONG A WEAKENING STATIONARY
FRONT/SURFACE TROUGH DRAPED OVER CENTRAL FLORIDA. STILL...SOME
CELL CLUSTERS ARE EXPECTED TO SPREAD INTO GLADES AND HENDRY COUNTY
FROM THE WEST BY 4PM EDT...AND CONTINUED CONVECTIVE INITIATION IS
FORECAST FOR PALM BEACH COUNTY...LIKELY EXTENDING INTO BROWARD
COUNTY WITH TIME...WHERE CONVERGENCE IS BEING ENHANCED DUE TO SEA-
BREEZE BOUNDARY. ELSEWHERE...ONLY ISOLATED TO SCATTERED
CONVECTION IS EXPECTED. PLENTY OF INSTABILITY AND SOMEWHAT FAVORABLE LOW-
LEVEL SHEAR FOR ANY THUNDERSTORMS TO WORK WITH...SO SOME RISK OF
STRONG WIND GUSTS AND POSSIBLY A FUNNEL/WATERSPOUT. PWATS ARE
STILL VERY HIGH...SO ANY ACTIVITY IS GOING TO HAVE VERY HIGH
RAINFALL RATES AND THERE IS CONCERN FOR LOCALIZED URBAN FLOODING.
THE RISK LATER THIS EVENING IS THAT LARGE CONVECTIVE COMPLEX
BETWEEN RSW AND TBW /EXTENDING WESTWARD INTO THE GULF/ WILL HAVE
SUFFICIENT COOL POOL FOR SOUTHWARD MOVING BOUNDARIES...LEADING TO
MORE COVERAGE OF SHOWERS AND THUNDERSTORMS NORTH OF A NAPLES TO
PALM BEACH LINE. POPS ARE HIGHEST THIS REGION THIS
EVENING...THOUGH CONFIDENCE IS LOW FOR THIS TIMEFRAME. OTHERWISE...
CONVECTION SHOULD FOR THE MOST PART DIMINISH DIURNALLY.
LITTLE SUPPORT FOR THE SURFACE BOUNDARY TO MOVE SOUTHWARD OUT OF
CENTRAL FLORIDA THROUGH THE SHORT TERM. HOWEVER...THE FEATURE WILL
LIKELY DRIFT TOWARD/INTO SOUTH FLORIDA WEDNESDAY AND THURSDAY.
THEREFORE...RAIN CHANCES REMAIN HIGH AND RISK FOR HEAVY RAIN MAY
ACTUALLY INCREASE DURING THIS PERIOD AS THE REGION GETS CLOSER TO
THE MAXIMIZED MOISTURE CONVERGENCE. WINDS GRADUALLY VEER MORE
WESTERLY OVER THE PERIOD. LATEST GUIDANCE SUGGEST FRONT WILL NOT
MAKE SIGNIFICANT PROGRESS SOUTH OF PENINSULA UNTIL IT RECEIVES
REINFORCING PUSH OF DRY AIR FROM THE NORTH ON THE HEELS OF A MID-
LATITUDE UPPER-LEVEL TROUGH AT THE END OF THE WEEK.
LONG TERM...
THE FRONT WILL CONTINUE TO MOVE SOUTH INTO THE FLORIDA STRAITS
THIS WEEKEND...AS THE HIGH OVER THE SOUTHEASTERN UNITED STATES
CONTINUES TO STRENGTHEN. THIS WILL ALLOW FOR THE WINDS OVER SOUTH
FLORIDA TO BECOME NORTHERLY AND BREEZY BRINGING IN THE DRIER AIR
FROM THE NORTH. SO THE POPS THIS WEEKEND WILL BE IN THE SLIGHT
CHANCE...EXCEPT LOW END CHANCE OVER THE WEST COAST METRO AREAS.
THE PWAT VALUES WILL ALSO BE FALLING FROM THE 1.7 INCHES EARLY
THIS WEEKEND TO 1.3 INCHES BY LATE THIS WEEKEND WHICH IS 2
STANDARD DEVIATIONS BELOW NORMAL. SO WILL KEEP A SLIGHT CHANCE OF
STORMS IN FOR THE INTERIOR AND WEST COAST METRO AREAS ON
SATURDAY...BEFORE REMOVING THE THUNDER THREAT FOR ALL OF SOUTH
FLORIDA FOR SUNDAY.
THE HIGH WILL REMAIN OVER THE SOUTHEAST UNITED STATES EARLY NEXT
WEEK KEEPING THE STEERING FLOW IN A NORTHEAST DIRECTION. THIS WILL
KEEP THE DRY WEATHER IN PLACE ALONG WITH THE VERY LOW PWAT VALUES.
SO THE POPS WILL REMAIN IN THE SLIGHT CHANCE WITH NO THREAT OF
THUNDER FOR EARLY NEXT WEEK.
AVIATION...
CURRENT SHOWERS/THUNDERSTORMS ARE IN THE VICINITY OF TERMINAL KPBI
WHICH WILL LIKELY BE IMPACTED 18Z TO 19Z WITH PERIODS OF BRIEF MVFR
TO VERY BRIEF IFR CONDITIONS POSSIBLE WITH PASSING
SHOWERS/THUNDERSTORMS. FOR THE REMAINDER OF THE
TERMINALS...CONVECTION HAS BEEN SUPPRESSED THROUGH 18Z BUT COULD
INITIATE AT ANY MOMENT THROUGH ABOUT 00Z...SO VCTS ASSIGNED EAST
COAST TAF`S AT 18Z. FOR TERMINAL KAPF...LINE OF SHOWERS/THUNDERSTORMS
TO THE NORTHWEST OF FT. MYERS COULD TRIGGER CONVECTION WITH VCTS
ASSIGNED AT 18Z...WITH BRIEF MVFR TO VERY BRIEF IFR CONDITIONS
POSSIBLE WITH PASSING SHOWERS/THUNDERSTORMS.
60
MARINE...
NUMEROUS SHOWERS AND THUNDERSTORMS WILL PREVAIL OVER SOUTH FLORIDA
WATERS WEDNESDAY AND THURSDAYS. DESPITE LOCALLY MUCH GUSTIER WINDS
IN AND NEAR CONVECTION...SYNOPTIC WINDS WILL BE SOUTHWEST AT 10 TO
15 KTS WEDNESDAY...THEN WEST AND NORTHWEST ON THURSDAY AT SIMILAR SPEEDS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 77 90 75 90 / 40 70 40 50
FORT LAUDERDALE 80 91 78 90 / 40 60 40 60
MIAMI 79 91 78 91 / 40 60 40 50
NAPLES 75 91 77 89 / 40 60 40 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...30/KOB
AVIATION/RADAR...85/AG
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
936 AM EDT MON SEP 23 2013
.UPDATE...
THE WEATHER PATTERN IN PLACE ACROSS THE REGION THIS MORNING IS
RATHER ACTIVE WITH A FRONTAL BOUNDARY DRAPED ACROSS NORTH FLORIDA
AND DEEP TROPICAL MOISTURE STREAMING IN FROM THE SOUTHWEST AHEAD
OF A TROUGH AND ASSOCIATED SURFACE LOW ALONG THE NORTHERN GULF
COAST. RADAR IMAGERY THIS MORNING SHOWS A LINE OF SHOWERS AND
STORMS MOVING NORTHEAST THROUGH THE CENTRAL AND SOUTHERN ZONES
WITH ANOTHER AREA OF RAIN OVER THE NORTHERN ZONES MOVING WEST TO
EAST IN ASSOCIATION WITH THE BOUNDARY. MORNING SOUNDINGS FROM
ACROSS THE REGION ARE ALL VERY MOIST AND WHEN COMBINED WITH
CONVERGENCE ALONG THE FRONTAL BOUNDARY TO THE NORTH AND SUPPORT
FROM THE TROUGH...RAIN CHANCES WILL BE HIGH THROUGH THE DAY TODAY.
THE HRRR AND OTHER HI-RES MODELS SUPPORT THIS THINKING. MADE SOME
UPDATES TO POPS FOR THIS MORNING INTO EARLY AFTERNOON BUT
OTHERWISE JUST ADJUSTED WINDS AND TEMPS BASED ON RECENT
OBSERVATIONS. NO OTHER UPDATES ARE PLANNED FOR THIS MORNING.
&&
.AVIATION...
VFR CONDITIONS WILL DETERIORATE AS SHOWERS MOVE INTO AREA TERMINALS
THIS MORNING...AND CONTINUE THROUGHOUT THE DAY. THUNDERSTORMS ARE
POSSIBLE ACROSS SOUTHERN TERMINALS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 87 76 87 77 / 70 50 70 40
FMY 88 76 88 77 / 70 50 70 40
GIF 87 74 87 74 / 70 50 70 40
SRQ 87 78 88 78 / 70 50 70 40
BKV 87 74 88 73 / 70 50 70 40
SPG 87 78 87 79 / 70 50 70 40
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE...05/CARLISLE
AVIATION...20/BARRON AND 75/LEWIS
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
920 AM EDT MON SEP 23 2013
.DISCUSSION...
...LOCALLY HEAVY RAIN EXPECTED ACROSS EAST CENTRAL FLORIDA INTO MID
WEEK...
.UPDATE...DEEP MOISTURE WITH PWATS FROM 2.25-2.30 INCHES ACROSS THE
SRN PENINSULA PER 12Z SOUNDINGS WILL BE ADVECTED NWD WITH INCREASING
SSW/SW FLOW IN THE H9-H8 LAYER TO 15-20 KNOTS ACROSS THE SRN HALF OF
THE FORECAST AREA THIS AFTERNOON. MODELS HINT AT A LOW TO MID LVL
SHORTWAVE TROUGH ACROSS THE ERN GULF THAT WILL ENHANCE NORTHEASTWARD
MOVING SHOWERS AND STORMS INTO CENTRAL AND SRN SECTIONS OF EAST
CENTRAL FLORIDA BY EARLY TO MID AFTERNOON. QUASI STATIONARY BOUNDARY
ACROSS THE NRN PENINSULA AND SOUPY AIRMASS SOUTH OF THE BOUNDARY
WILL LIKELY PROVIDE FOCUS FOR SHOWERS AND STORMS ACROSS NRN SECTIONS
AS WELL INTO THE MID TO LATE AFTERNOON. FIRST ROUND OF CONVECTION IS
ALREADY MOVING NE FROM SW FLORIDA AND WILL APPROACH SRN INTERIOR
SECTIONS BY MID DAY. WILL CONTINUE LIKELY RAIN CHANCES. HIGHS
EXPECTED MAINLY IN THE UPR 80S WITH SOME AREAS APPROACHING 90 THAT
SEE LESS CLOUD COVER ACROSS THE SOUTH. EXPECT LOCALLY HEAVY RAINFALL
AMOUNTS UP TO AROUND TWO INCHES...ESPECIALLY ACROSS SRN/CENTRAL
SECTIONS WHERE FILTERED SUNSHINE THIS MORNING SHOULD PROVIDE
SLIGHTLY BETTER INSTABILITY. WARM MID LEVEL TEMPERATURES INDICATIVE
OF TROPICAL AIRMASS WITH HIGH PWATS. EXPECT SOME GUSTY WINDS TO
40-45 MPH WITH STRONGEST STORMS.
&&
.AVIATION...CURRENT EXTRAPOLATION PLACES SW FL CONVECTION CLOSE TO A
KMCO-KVRB-KFPR LINE AROUND 18Z. WITH STRONGER DEVELOPING LOW LVL
SW FLOW ACROSS SRN PORTIONS OF EAST CENTRAL FL MAY NEED TO ADJUST
TIMING OF SHRA/TSRA JUST A BIT SOONER. HRRR MODEL SLIGHTLY SLOWER
WITH CONVECTION MOVING NE. WILL KEEP AN EYE ON RADAR TRENDS AND
ADJUST CONVECTIVE TIMING AS NECESSARY.
&&
.MARINE...
NEARLY CALM WIND CURRENTLY AT BUOY 41009 WITH SEAS 2 FT AT BUOY
41009/41114. MAIN CONCERN TODAY WILL BE SHOWERS/TSTMS MOVING FROM
THE MAINLAND INTO THE NEAR SHORE WATERS FROM THE BREVARD-VOLUSIA
COUNTY LINE SOUTH TO JUPITER INLET THIS AFTERNOON. POTENTIAL FOR 35
KT GUSTS WITH STORMS. BUOY 41009 RECORDED A 31 KT GUST YESTERDAY AND
KDAB RECORDED A GUST TO 35 KNOTS. SIMILAR GUST POTENTIAL TODAY FROM
30-40 KTS EXPECTED WITH STRONGEST STORMS.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
VOLKMER/WIMMER
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
503 AM EDT Mon Sep 23 2013
...Locally Heavy Rain Possible Through Mid Week...
.Near Term [Through Today]...
As was picked up well by the previous shift and the Hi-Res Models,
Convection with some heavy precip has begun to form early this
morning over the western FL Panhandle. Dual-Pol Radar estimates of
3-4.5" of rain have already fallen over Southeastern sections of
Walton county (mostly rural areas) in the last 6 hrs, so Urban and
Small Stream Flood Advisories should be sufficient at this point.
Although not much rain at all has fallen over Holmes and Washington
counties as of yet, this Meso-Low could help curl these heavier
precip bands off to the NNE and affect some of our most vulnerable
areas which have been hit quite hard earlier this summer with Flash
Flooding, so they certainly do not need the extra rainfall. The good
news, however, is that the highest PoPs and QPF are expected this
morning, as the Hi-Res WRFs and HRRR have been consistent in showing
a diminishing trend in the rainfall this afternoon. So clearly, the
greatest threat for flooding will be this morning. Also with all of
the extensive Cloud Cover and areas of rain, actually went with our
4 km WRF for both High, and hourly temperatures over the interior,
which only peak out in the upper 70s to lower 80s in most cases.
&&
.SHORT TERM [Tonight Through Wednesday]...
The unsettled weather pattern with a warm and moist airmass and
bouts of moderate to locally heavy rain will continue through the
period. Timing of heavy rain tricky given model differences and this
needs to be monitored to pinpoint forecasts. GFS and ECMWF seem to
have good model to model consistency and less aggressive than NAM
QPF and leaned towards GFS/ECMWF blending.
The large scale amplified pattern commences tonight with a deepening
trough over Cntrl Conus with low over NEB and axis Swd into TX. This
allows ridge to build briefly over Ern states including local
region. At the surface, low over Canadian Maritimes with cold front
Swd down extreme Wrn Atlc then Wwd becoming weaker and stationary
over FL coast or extreme Nrn Gulf of Mex waters connecting to low
around 100 miles south of Wrn LA Coast. Isentropic lift along and
north of boundary should provide enough lingering moisture and
low-level convergence for scattered showers and isolated
thunderstorms, especially near the coast and over the coastal
waters. Will go with 0-40% land and 40-60% marine N-S POP
gradient.
On Tuesday, as H5 shortwave moves out of Plains, Cntrl trough moves
Ewd reaching OH Valley by sundown shunting downstream ridge towards
Atlc. This added upper support will pick up LA low and help to
re-activate front. As a result, low begins to open up and track ENE
across Panhandle late. Aided by a few impulses moving SW-NE, the
front lifts back Nwd as a warm front with enhanced low level
convergence to around FL/AL/GA border. Area dew points rise to the
upper 60s Nrn counties to the low 70s Srn counties. This should
lead to another round of moderate to occasionally heavy rainfall
late into the night especially Wrn counties. Progressive movement
of upper and lower features suggest a limited flood threat but
given antecedent conditions, this will need to be monitored. Will
go with 70-40% SW-NE POP gradient daytime and 50-60% everywhere at
night.
On Wednesday, above shortwave reaches Lwr MS Valley before ejecting
EWD. This allows surface low to lifts ENE along warm front and
across our area during morning with highest POPs shifting to NE
tier counties. This will be our best shot for strong storms (see
below). With grounds likely saturated, the threat of flash
flooding remains elevated. Trough/low forecast to move east into
Atlc with trough axis along or just east of FL coast by sundown.
This should push the bulk of the forcing for precip off the east
coast as well. Thus, expect rainfall to taper off from west to
east during the day. Will go with 40-60% W-E POP gradient in
morning decreasing to 30-50% in the afternoon.
Although strong to severe storms are deemphasized, increasing shear
with advancing warm front plus shortwave may overcome weak instability,
weak lapse rates and warm H5 temperatures and generate gusty winds
and even a rotating cell or two especially when it interacts with
land mass and this needs to be monitored. With plenty of cloud
cover expected through midweek, we undercut GFS/NAM a few degrees.
With clouds and rain, expect high temperatures to hold in the mid
80s for most locations. Nights will be muggy. QPF for today
through Wednesday ranges from 1.5 to 2 inches over Florida and
0.60 to 1.5 inches over Georgia and Alabama. However locally
higher amounts are likely with periods of moderate to heavy rain
near frontal boundary.
&&
.LONG TERM [Wednesday Night through Sunday]...
For the latter half of the week, a significant ridge is forecast to
develop from the central Gulf Coast northward into the Ohio Valley.
At the surface, high pressure centered over New England will nose
down the eastern seaboard into the northeastern Gulf. This should
allow for a progressively cooler and drier airmass to push into the
region by late in the week, with noticeably cooler high temperatures
and pleasant morning lows.
&&
.Aviation...
[Through 12 UTC Tuesday] Conditions will be quite variable at the
terminals during the next 24 hours, with the greatest likelihood for
IFR or lower Cigs and Vis will at TLH, ECP, and VLD where the
highest PoPs and QPF are expected through the period. Currently only
expect VFR with possible MVFR conditions at ABY and DHN, but this
could change if the High Cloud Canopy Dissipates.
&&
.MARINE...
A frontal boundary south over the waters will weaken today. onshore
winds this morning will become easterly and increase slightly
tonight night as high pressure builds north of the waters. Weak low
pressure over Wrn Gulf today will pass NE and across the waters by
the middle of the week. At this time, winds are forecast to remain
below headline criteria but winds and seas will be high near any
showers and tstms.
&&
.Fire Weather...
Continued wet conditions will keep relative humidities very high for
the next several days.
&&
.HYDROLOGY...
Roughly 1 to 3 inches of rain has fallen across the region this
weekend, with the highest amounts close to the coast. Over the next
several days, another 1.5 to 2.5 inches will be possible with
locally higher amounts. This will be enough to generate minor rises
on area rivers. With the current forecast, widespread riverine
flooding appears unlikely. However, some localized flooding issues
may develop (especially in urban areas) if heavy rain can become
focused enough spatially and temporally.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 79 71 86 71 88 / 70 40 50 60 60
Panama City 82 74 85 73 86 / 70 40 60 60 50
Dothan 81 69 86 70 87 / 20 20 50 60 50
Albany 81 68 85 70 87 / 20 20 40 60 50
Valdosta 81 68 86 70 86 / 70 20 50 50 60
Cross City 85 70 86 72 88 / 70 40 60 50 60
Apalachicola 84 76 84 76 85 / 70 40 60 60 60
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...Gould
SHORT TERM...Block
LONG TERM...Camp
AVIATION...Gould
MARINE...Block
FIRE WEATHER...Gould
HYDROLOGY...Lamers/Block
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
456 AM EDT Mon Sep 23 2013
...Locally Heavy Possible Through Mid Week...
.Near Term [Through Today]...
As was picked up well by the previous shift and the Hi-Res Models,
Convection with some heavy precip has begun to form early this
morning over the western FL Panhandle. Dual-Pol Radar estimates of
3-4.5" of rain have already fallen over Southeastern sections of
Walton county (mostly rural areas) in the last 6 hrs, so Urban and
Small Stream Flood Advisories should be sufficient at this point.
Although not much rain at all has fallen over Holmes and Washington
counties as of yet, this Meso-Low could help curl these heavier
precip bands off to the NNE and affect some of our most vulnerable
areas which have been hit quite hard earlier this summer with Flash
Flooding, so they certainly do not need the extra rainfall. The good
news, however, is that the highest PoPs and QPF are expected this
morning, as the Hi-Res WRFs and HRRR have been consistent in showing
a diminishing trend in the rainfall this afternoon. So clearly, the
greatest threat for flooding will be this morning. Also with all of
the extensive Cloud Cover and areas of rain, actually went with our
4 km WRF for both High, and hourly temperatures over the interior,
which only peak out in the upper 70s to lower 80s in most cases.
&&
.SHORT TERM [Tonight Through Wednesday]...
The unsettled weather pattern with a warm and moist airmass and
bouts of moderate to locally heavy rain will continue through the
period. Timing of heavy rain tricky given model differences and this
needs to be monitored to pinpoint forecasts. GFS and ECMWF seem to
have good model to model consistency and less aggressive than NAM
QPF and leaned towards GFS/ECMWF blending.
The large scale amplified pattern commences tonight with a deepening
trough over Cntrl Conus with low over NEB and axis Swd into TX. This
allows ridge to build briefly over Ern states including local
region. At the surface, low over Canadian Maritimes with cold front
Swd down extreme Wrn Atlc then Wwd becoming weaker and stationary
over FL coast or extreme Nrn Gulf of Mex waters connecting to low
around 100 miles south of Wrn LA Coast. Isentropic lift along and
north of boundary should provide enough lingering moisture and
low-level convergence for scattered showers and isolated
thunderstorms, especially near the coast and over the coastal
waters. Will go with 0-40% land and 40-60% marine N-S POP
gradient.
On Tuesday, as H5 shortwave moves out of Plains, Cntrl trough moves
Ewd reaching OH Valley by sundown shunting downstream ridge towards
Atlc. This added upper support will pick up LA low and help to
re-activate front. As a result, low begins to open up and track ENE
across Panhandle late. Aided by a few impulses moving SW-NE, the
front lifts back Nwd as a warm front with enhanced low level
convergence to around FL/AL/GA border. Area dew points rise to the
upper 60s Nrn counties to the low 70s Srn counties. This should
lead to another round of moderate to occasionally heavy rainfall
late into the night especially Wrn counties. Progressive movement
of upper and lower features suggest a limited flood threat but
given antecedent conditions, this will need to be monitored. Will
go with 70-40% SW-NE POP gradient daytime and 50-60% everywhere at
night.
On Wednesday, above shortwave reaches Lwr MS Valley before ejecting
EWD. This allows surface low to lifts ENE along warm front and
across our area during morning with highest POPs shifting to NE
tier counties. This will be our best shot for strong storms (see
below). With grounds likely saturated, the threat of flash
flooding remains elevated. Trough/low forecast to move east into
Atlc with trough axis along or just east of FL coast by sundown.
This should push the bulk of the forcing for precip off the east
coast as well. Thus, expect rainfall to taper off from west to
east during the day. Will go with 40-60% W-E POP gradient in
morning decreasing to 30-50% in the afternoon.
Although strong to severe storms are deemphasized, increasing shear
with advancing warm front plus shortwave may overcome weak instability,
weak lapse rates and warm H5 temperatures and generate gusty winds
and even a rotating cell or two especially when it interacts with
land mass and this needs to be monitored. With plenty of cloud
cover expected through midweek, we undercut GFS/NAM a few degrees.
With clouds and rain, expect high temperatures to hold in the mid
80s for most locations. Nights will be muggy. QPF for today
through Wednesday ranges from 1.5 to 2 inches over Florida and
0.60 to 1.5 inches over Georgia and Alabama. However locally
higher amounts are likely with periods of moderate to heavy rain
near frontal boundary.
&&
.LONG TERM [Wednesday Night through Sunday]...
For the latter half of the week, a significant ridge is forecast to
develop from the central Gulf Coast northward into the Ohio Valley.
At the surface, high pressure centered over New England will nose
down the eastern seaboard into the northeastern Gulf. This should
allow for a progressively cooler and drier airmass to push into the
region by late in the week, with noticeably cooler high temperatures
and pleasant morning lows.
&&
.Aviation...
[Through 12 UTC Tuesday] Conditions will be quite variable at the
terminals during the next 24 hours, with the greatest likelihood for
IFR or lower Cigs and Vis will at TLH, ECP, and VLD where the
highest PoPs and QPF are expected through the period. Currently only
expect VFR with possible MVFR conditions at ABY and DHN, but this
could change if the High Cloud Canopy Dissipates.
&&
.MARINE...
A frontal boundary south over the waters will weaken today. onshore
winds this morning will become easterly and increase slightly
tonight night as high pressure builds north of the waters. Weak low
pressure over Wrn Gulf today will pass NE and across the waters by
the middle of the week. At this time, winds are forecast to remain
below headline criteria but winds and seas will be high near any
showers and tstms.
&&
.Fire Weather...
Continued wet conditions will keep relative humidities very high for
the next several days.
&&
.HYDROLOGY...
Roughly 1 to 3 inches of rain has fallen across the region this
weekend, with the highest amounts close to the coast. Over the next
several days, another 1.5 to 2.5 inches will be possible with
locally higher amounts. This will be enough to generate minor rises
on area rivers. With the current forecast, widespread riverine
flooding appears unlikely. However, some localized flooding issues
may develop (especially in urban areas) if heavy rain can become
focused enough spatially and temporally.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 79 71 86 71 88 / 70 40 50 60 60
Panama City 82 74 85 73 86 / 70 40 60 60 50
Dothan 81 69 86 70 87 / 20 20 50 60 50
Albany 81 68 85 70 87 / 20 20 40 60 50
Valdosta 81 68 86 70 86 / 70 20 50 50 60
Cross City 85 70 86 72 88 / 70 40 60 50 60
Apalachicola 84 76 84 76 85 / 70 40 60 60 60
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...Gould
SHORT TERM...Block
LONG TERM...Camp
AVIATION...Gould
MARINE...Block
FIRE WEATHER...Gould
HYDROLOGY...Lamers/Block
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1000 PM CDT TUE SEP 24 2013
.DISCUSSION...
246 PM CDT
PRIMARY FORECAST CHALLENGE REMAINS THE DECAYING UPPER LOW MOVING
ACROSS THE AREA LATER TONIGHT INTO WEDNESDAY MORNING AND
TIMING/IMPACTS OF WEEKEND SYSTEM.
SHORT TERM (TONIGHT THROUGH FRIDAY)...
CLOSED UPPER LOW OVER IOWA CONTINUES WEAKEN AS IT PUSHES EASTWARD
INTO THE RATHER HIGH AMPLITUDE UPPER RIDGE OVER THE GREAT LAKES AND
OHIO VALLEY. INTERESTINGLY...THE PAST COUPLE RUNS OF THE ECMWF TAKE
THIS SYSTEM OFF THE EAST COAST LATER THIS WEEK AND SHOW IT EVOLVING
INTO A SUB-TROPICAL OR TROPICAL STORM OFF THE EAST COAST BY EARLY
NEXT WEEK! MAIN EFFECTS OF THIS SYSTEM AS IT BRUSHES BY OUR AREA
LATER TONIGHT INTO EARLY WEDNESDAY WILL BE AN INCREASE IN MID-HIGH
LEVEL CLOUDINESS...ESPECIALLY SOUTHERN CWA WHERE A FEW SPRINKLES
FROM THE MID LEVEL DECK CANNOT BE RULED OUT. AS THIS SYSTEM MOVES
EAST LATER WEDNESDAY THE STAGE WILL BE SET FOR SEVERAL DAYS OF
SUNSHINE AND A SLOW WARMING TREND. WARMING TEMPS THROUGH FRIDAY BUT
WITH SOME DEGREE OF AN EASTERLY COMPONENT TO THE SYNOPTIC FLOW
EXPECT TEMPS OVER NE IL (ESPECIALLY RIGHT ALONG THE LAKE) TO REMAIN
A BIT COOLER.
IZZI
LONG TERM (FRIDAY NIGHT THROUGH TUESDAY)...
THOUGH SOME GUIDANCE...NAMELY THE GFS AND ITS ENSEMBLES AND THE
CANADIAN...HAVE TRENDED FASTER WITH FROPA LATE SATURDAY INTO
SUNDAY...FEEL THAT THE STRENGTH OF THE HIGH AMPLITUDE UPPER RIDGE
AHEAD OF FRONT WILL RESULT IN SLOWER PROGRESSION SIMILAR TO 00Z
ECMWF. THERMAL RIDGE WILL BE SQUARELY OVERHEAD ON SAT/850 MB TEMPS
MID TEENS AND 925 MB TEMPS NEARING 20C/AND FORECAST SOUNDINGS
SUGGESTING MINIMAL CLOUD COVER AND MIXING UP TO 850 MB. THUS HAVE
RAISED TEMPS ABOVE GUIDANCE BLEND AND A BIT ABOVE PREVIOUS FORECAST
TO LOW/MID 80S.
FASTER GUIDANCE DOES SUGGEST FRONTAL PRECIP INTO WESTERN CWA BY
SATURDAY EVENING...BUT MAINTAINED SLOWER IDEA FROM PREVIOUS FCST
WITH HIGHEST POPS AFTER MIDNIGHT AND CHANCE POPS INTO
SUNDAY...DIMINISHING FROM THE WEST IN THE AFTERNOON. MINIMAL
MOISTURE RETURN AND RESULT MEAGER INSTABILITY (AT BEST) WILL
PRECLUDE MUCH OF A THREAT FOR THUNDER...BUT DUE TO SHARPNESS OF
UPPER TROUGH DIGGING IN WITH FRONT...IT SEEMS REASONABLE TO KEEP A
SLIGHT CHANCE OF THUNDER IN THE GRIDS. THE EVOLUTION OF CLOSED
UPPER LOW OVER IOWA TODAY THAT COULD SPUR HYBRID TROPICAL
DEVELOPMENT OFF THE EAST COAST OVER THE WEEKEND WILL LIKELY PLAY A
ROLE IN SPEED OF PROGRESSION OF SURFACE AND UPPER FEATURES.
THEN BEHIND THE FRONT EARLY NEXT WORK WEEK...AIRMASS WILL BE OF
PACIFIC ORIGIN...RESULTING IN HIGHS SLIGHTLY ABOVE NORMAL ON MONDAY
AND THEN STRONG HEIGHT RISES OVER CENTRAL CONUS ON TUESDAY COULD
YIELD TEMPS WELL ABOVE NORMAL UPPER 60S/LOW 70S. HAVE GONE ABOVE
STRAIGHT GUIDANCE BLEND TO LOW-MID 70S MON AND SOLIDLY MID 70S
TUESDAY CLOSER TO WARMER GUIDANCE BASED ON UPPER AIR CLIMO. HOWEVER
A PEAK AT 12Z ECMWF SUGGESTS MONDAY COULD BE WARMER THAN TUESDAY
THANKS TO COLD FRONT AND FAIRLY SHARP UPPER TROUGH DIVING IN FROM
NORTHWEST ON TUESDAY.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* NONE.
KJB
//DISCUSSION...UPDATED 00Z...
NO WEATHER CONCERNS EXPECTED THROUGH THE PERIOD.
HIGH PRESSURE WILL CONTINUE TO DOMINATE ACROSS THE GREAT LAKES
REGION THROUGH THE PERIOD. A WEAK SURFACE LOW WILL PASS EAST-
SOUTHEASTWARD ACROSS MISSOURI AND INTO THE SOUTHEASTERN STATES
TONIGHT INTO WEDNESDAY...WHICH WILL ALLOW THE WINDS TO REMAIN
EASTERLY THROUGH THE PERIOD. OVERALL...VFR CONDITIONS ARE
EXPECTED...BUT SOME MID LEVEL CLOUDINESS SHOULD INCREASE ACROSS
THE AREA OVERNIGHT.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH FOR ALL ELEMENTS.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
* THURSDAY THROUGH SATURDAY...DRY/VFR.
* SATURDAY NIGHT AND SUNDAY...CHANCE OF SHRA/TSRA.
* MONDAY...DRY/VFR.
KJB
&&
.MARINE...
305 PM...A LARGE AREA OF HIGH PRESSURE CENTERED OVER THE EASTERN
GREAT LAKES WILL REMAIN NEARLY STATIONARY THROUGH FRIDAY AND THEN
SHIFT EAST OVER NEW ENGLAND ON SATURDAY. MEANWHILE...WEAK LOW
PRESSURE OVER MISSOURI WILL TRACK EAST INTO THE TENNESSEE VALLEY
WEDNESDAY AND THEN DISSIPATE BY THURSDAY. A STRONGER IS EXPECTED
TO DEVELOP OVER THE NORTHERN PLAINS WEDNESDAY NIGHT AND THEN LIFT
NORTH INTO MANITOBA ON FRIDAY. ANOTHER LOW IS EXPECTED TO MOVE
OUT OF THE CENTRAL ROCKIES AND INTO THE CENTRAL PLAINS ON THURSDAY
NIGHT AND FRIDAY. THIS LOW WILL THEN ELONGATE AND MERGE WITH THE
SYSTEM THAT LIFTED INTO MANITOBA...WITH A TROUGH OF LOW PRESSURE
AND AN ASSOCIATED COLD FRONT EXTENDING SOUTHWEST INTO EASTERN
COLORADO. THIS SYSTEM WILL SLOWLY TRACK ACROSS THE PLAINS FRIDAY
AND SATURDAY...WITH THE COLD FRONT FINALLY PUSHING ACROSS LAKE
MICHIGAN SATURDAY NIGHT OR SUNDAY.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
National Weather Service Lincoln IL
859 PM CDT Tue Sep 24 2013
.DISCUSSION...
ISSUED 859 PM CDT Tue Sep 24 2013
Showers and isolated thunderstorms have developed to the south and
southwest of the area and will be moving north into the region
this evening. HRRR model has a fairly good handle on this and
identifies where the strongest area will be. HRRR pushes the pcpn
into the area south of a Jacksonville to Paris line through 06z
and then weakens the pcpn after midnight. So will be updating the
pops/wx in the forecast for this evening, reflecting closer to
what the new HRRR model run shows. Clouds will remain partly to
mostly cloudy as well. Remainder of the forecast looks fine. So,
updated forecast for pops/wx will be forthcoming shortly.
Auten
&&
.AVIATION...
ISSUED 613 PM CDT Tue Sep 24 2013
VFR conditions will prevail next 24hrs at all TAF sites. Scattered
to broken clouds will continue over the area this evening and
overnight. Some very light showers were moving across the area.
Other showers were developing out west of the state, but were
moving north at the moment. These showers could reach into the
area and could affect TAF sites of SPI and DEC later this evening.
Models do develop this little area but dissipate it late this
evening as the whole system move east southeast. So, think PIA/BMI
and CMI will not see any showers. So will have VCSH mentioned at
SPI and DEC only this evening til about midnight. Unsure of how
much cloud cover will be around tomorrow, but looks like it starts
as broken and then becomes scattered during the afternoon. Winds
will be easterly but become northeasterly for overnight and then
back to easterly again tomorrow. Wind speeds will be light tonight
and then 5-8kts through the 24hr period.
Auten
&&
.PREV DISCUSSION...
ISSUED 243 PM CDT Tue Sep 24 2013
Mostly quiet weather for the forecast with a couple of exceptions.
The first one is the weak low pressure system in northern MO this
afternoon and the associated series of upper waves. Several small
disturbances rotating through the 500mb trof resulting in a
continuation of pops through the overnight hours for the southern
half of Illinois. Quiet and slowly warming temperatures through
the first half of the weekend until the next weather maker moves
through the Midwest late Saturday/Sunday with a return of showers
and thunderstorms for the region. For the most part, models in
good agreement...however, frontal passage over the weekend is a
bit more problematic in regards to timing in previous runs. 12z
runs have better continuity and dry out the Midwest again for the
start of next week.
SHORT TERM...Tonight and tomorrow...
Upper low moving through the region tonight and tomorrow morning,
becoming more of an open wave tomorrow as the surface low dives to
the southeast and weakens. Sat imagery this afternoon showing
several distinct disturbances in the broader trof. In combination
with enough moisture to the southeast to sustain some sct showers
and thunder this morning...will keep the low chance pops in the
south/southeast through the overnight hours. Slight chance pops in
the south for tomorrow will remain in place for the
slowing/opening of the upper trof and general diffuse potential
for any mesoscale triggers. Widespread showers not anticipated
with this system. Overnight lows tonight a little warmer with
expected cloud cover, especially in the southeast. Guidance for
tomorrow night a little more spread with some variability in
residual moisture/clouds in the region with the more open wave.
LONG TERM...Thursday through Monday...
Slowly moderating temperatures through the end of the week...with
midlevel temps climbing from 10C to closer to 15-16C as the
thermal ridge to the west shifts eastward across the country. Dry
weather anticipated until the next cold front late Saturday.
Though timing has been a bit conflicted over the last few runs,
the 12z models are far more together with the timing...but a
little less so with the location of the main sfc low. ECMWF
further south, which would likely impact strength of dynamics for
the storms to pull from. GFS further north with the best energy
and leaving a narrow and quick progression through the region.
ECMWF also magnifying a low in the Atlantic which may or may not
impact timing of the exit of the front in the next few runs. For
now, precip confined to Sat night through Sun night with best
chances Sat night/Sunday. Cooler start to the next work week behind
the front.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1020 PM EDT TUE SEP 24 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 330 PM EDT TUE SEP 24 2013
AN UPPER LEVEL LOW ACCOMPANIED BY A SURFACE LOW WILL MOVE THROUGH
THE OHIO VALLEY LATE TONIGHT AND WEDNESDAY BRINGING LOW CHANCES FOR
LIGHT RAIN SHOWERS ACROSS THE SOUTHERN HALF OF OUR REGION.
HIGH PRESSURE AND DRY WEATHER WILL BE THE RULE FROM LATE WEDNESDAY
THROUGH SATURDAY. A COLD FRONT WILL BRINGS A GOOD CHANCE FOR RAIN
SHOWERS AROUND SUNDAY FOLLOWED BY DRY WEATHER MONDAY AND TUESDAY.
TEMPERATURES WILL BECOME QUITE WARM FRIDAY AND SATURDAY AND A LITTLE
COOLER EARLY NEXT WEEK.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 1006 PM EDT TUE SEP 24 2013
PRECIP HAS STRUGGLED TO MAKE EASTWARD PROGRESSION THIS
EVENING...AND THUNDERSTORMS HAVE BEEN CONFINED TO AN AREA NEAR ST
LOUIS AND ANOTHER AREA ALONG THE TN/KY BORDER. HAVE ADJUSTED POPS
OVERNIGHT IN LINE WITH THESE TRENDS AND HRRR GUIDANCE. STILL
MAINLY FOCUSING SHOWER CHANCES ON THE SOUTH/SOUTHWEST. TEMPS LOOK
TO BE IN GOOD SHAPE AND DID NOT REQUIRE ADJUSTMENT.
PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 330 PM EDT TUE SEP 24 2013
AN UPPER LOW CENTERED NEAR KANSAS CITY WILL MOVE TO THE SOUTHERN
PART OF OUR REGION LATE TONIGHT. MODELS INDICATE A FAIR AMOUNT OF
FORCING MAINLY LATE TONIGHT. SOME MOISTURE HAS WORKED INTO THE
LOWER OHIO VALLEY WHILE CENTRAL AND NORTHERN PORTIONS OF OUR REGION
ARE STILL VERY DRY. NAM HAS BEEN SOMEWHAT OVERLY AGGRESSIVE IN
PUSHING MOISTURE INTO OUR REGION AND MOST ENSEMBLES INDICATE LATE OR
NO PRECIPITATION. WILL MENTION LOW CHANCES OF SHOWERS ACROSS THE
SOUTHWEST THIS EVENING AND MOST OF THE SOUTH LATE TONIGHT.
WILL KEEP ALL AREAS DRY ALONG AND NORTH OF A ROCKVILLE TO
INDIANAPOLIS AND RUSHVILLE LINE. CONCERNING TEMPERATURES...A MOS
BLEND SEEMS REASONABLE.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ISSUED AT 330 PM EDT TUE SEP 24 2013
FOCUS IS ON CHANCES FOR RAIN CHANCES WEDNESDAY. A FEW SHOWERS MAY
LINGER ACROSS THE SOUTH HALF OF OUR REGION UNTIL MID AFTERNOON
WEDNESDAY. FORCING IS WEEK...SO WILL GO MORE THAN A 20 PERCENT
CHANCE OF LIGHT SHOWERS OVER THE SOUTHERN 2-3 ROW OF COUNTIES.
THE UPPER LOW WILL MOVE ON TO THE EAST AND MODELS BUILD AN UPPER
RIDGE OF HIGH PRESSURE INTO THE MISSISSIPPI VALLEY THURSDAY AND
ACROSS OUR REGION FRIDAY. EXPECT MOSTLY CLEAR SKIES AND WARMER
DAYTIME TEMPERATURES...ESPECIALLY FRIDAY. WENT CLOSE A MOS BLEND ON
TEMPERATES...EXCEPT A TAD LOWER AT INDY ON THURSDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ISSUED AT 330 PM EDT TUE SEP 24 2013
THE BEGINNING OF THE EXTENDED PERIOD WILL START OUT DRY WITH RIDGING
OVER THE FORECAST AREA. HOWEVER...FOCUS QUICKLY TURNS TO AN
APPROACHING COLD FRONT EXTENDING FROM ONTARIO TO THE SOUTHERN U.S.
MODELS ARE INDICATING A NARROW BUT WELL-DEFINED PLUME OF MOISTURE
ALONG THE ENTIRE LENGTH OF THAT FRONT. LATEST INITIALIZATION SEEMS
TO BE FAVORING THE SLIGHTLY FASTER GFS OVER THE EURO...WHICH BRINGS
PRECIP INTO WESTERN PORTIONS OF FORECAST AREA BY SATURDAY NIGHT.
INITIALIZATION WAS ALSO TRENDING TOWARD LIKELY POPS FOR SUNDAY... SO
DECIDED TO BE AGGRESSIVE WITH POPS DUE TO SUFFICIENT LIFT ALONG AND
AHEAD OF FRONT. TEMPS WILL CLIMB BACK INTO THE LOW 80S ON
SATURDAY...BUT WILL QUICKLY PLUMMET CLOSER TO NORMAL IN WAKE OF THE
AFOREMENTIONED COLD FRONT.
&&
.AVIATION /DISCUSSION FOR THE 25/0300Z IND TAF UPDATE/...
ISSUED AT 1020 PM EDT TUE SEP 24 2013
ADDED BROKEN 5K FOOT CEILING PER SATELLITE AND OBSERVATIONAL
TRENDS...OTHERWISE NO CHANGES.
PREVIOUS DISCUSSION FOLLOWS...
ASIDE FROM THE POTENTIAL FOR SOME MVFR OR WORSE FOG AT HUF AND
BMG...PRETTY GOOD CONFIDENCE IN VFR THROUGH THE TAF PERIOD AS A LOW
PRESSURE SYSTEM DROPS SOUTHEAST ACROSS THE MIDDLE MISSISSIPPI AND
TENNESSEE VALLEYS. ALSO...KEPT VCSH IN AT THOSE SITES AS THERE WILL
BE BETTER MOISTURE AND LIFT THERE ASSOCIATED WITH THE LOW PRESSURE
SYSTEM.
WINDS WILL BE EAST AND NORTHEAST 7 KNOTS OR LESS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH/NIELD
SHORT TERM...JH
LONG TERM....TDUD
AVIATION...MK
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1006 PM EDT TUE SEP 24 2013
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 330 PM EDT TUE SEP 24 2013
AN UPPER LEVEL LOW ACCOMPANIED BY A SURFACE LOW WILL MOVE THROUGH
THE OHIO VALLEY LATE TONIGHT AND WEDNESDAY BRINGING LOW CHANCES FOR
LIGHT RAIN SHOWERS ACROSS THE SOUTHERN HALF OF OUR REGION.
HIGH PRESSURE AND DRY WEATHER WILL BE THE RULE FROM LATE WEDNESDAY
THROUGH SATURDAY. A COLD FRONT WILL BRINGS A GOOD CHANCE FOR RAIN
SHOWERS AROUND SUNDAY FOLLOWED BY DRY WEATHER MONDAY AND TUESDAY.
TEMPERATURES WILL BECOME QUITE WARM FRIDAY AND SATURDAY AND A LITTLE
COOLER EARLY NEXT WEEK.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 1006 PM EDT TUE SEP 24 2013
PRECIP HAS STRUGGLED TO MAKE EASTWARD PROGRESSION THIS
EVENING...AND THUNDERSTORMS HAVE BEEN CONFINED TO AN AREA NEAR ST
LOUIS AND ANOTHER AREA ALONG THE TN/KY BORDER. HAVE ADJUSTED POPS
OVERNIGHT IN LINE WITH THESE TRENDS AND HRRR GUIDANCE. STILL
MAINLY FOCUSING SHOWER CHANCES ON THE SOUTH/SOUTHWEST. TEMPS LOOK
TO BE IN GOOD SHAPE AND DID NOT REQUIRE ADJUSTMENT.
PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 330 PM EDT TUE SEP 24 2013
AN UPPER LOW CENTERED NEAR KANSAS CITY WILL MOVE TO THE SOUTHERN
PART OF OUR REGION LATE TONIGHT. MODELS INDICATE A FAIR AMOUNT OF
FORCING MAINLY LATE TONIGHT. SOME MOISTURE HAS WORKED INTO THE
LOWER OHIO VALLEY WHILE CENTRAL AND NORTHERN PORTIONS OF OUR REGION
ARE STILL VERY DRY. NAM HAS BEEN SOMEWHAT OVERLY AGGRESSIVE IN
PUSHING MOISTURE INTO OUR REGION AND MOST ENSEMBLES INDICATE LATE OR
NO PRECIPITATION. WILL MENTION LOW CHANCES OF SHOWERS ACROSS THE
SOUTHWEST THIS EVENING AND MOST OF THE SOUTH LATE TONIGHT.
WILL KEEP ALL AREAS DRY ALONG AND NORTH OF A ROCKVILLE TO
INDIANAPOLIS AND RUSHVILLE LINE. CONCERNING TEMPERATURES...A MOS
BLEND SEEMS REASONABLE.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ISSUED AT 330 PM EDT TUE SEP 24 2013
FOCUS IS ON CHANCES FOR RAIN CHANCES WEDNESDAY. A FEW SHOWERS MAY
LINGER ACROSS THE SOUTH HALF OF OUR REGION UNTIL MID AFTERNOON
WEDNESDAY. FORCING IS WEEK...SO WILL GO MORE THAN A 20 PERCENT
CHANCE OF LIGHT SHOWERS OVER THE SOUTHERN 2-3 ROW OF COUNTIES.
THE UPPER LOW WILL MOVE ON TO THE EAST AND MODELS BUILD AN UPPER
RIDGE OF HIGH PRESSURE INTO THE MISSISSIPPI VALLEY THURSDAY AND
ACROSS OUR REGION FRIDAY. EXPECT MOSTLY CLEAR SKIES AND WARMER
DAYTIME TEMPERATURES...ESPECIALLY FRIDAY. WENT CLOSE A MOS BLEND ON
TEMPERATES...EXCEPT A TAD LOWER AT INDY ON THURSDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ISSUED AT 330 PM EDT TUE SEP 24 2013
THE BEGINNING OF THE EXTENDED PERIOD WILL START OUT DRY WITH RIDGING
OVER THE FORECAST AREA. HOWEVER...FOCUS QUICKLY TURNS TO AN
APPROACHING COLD FRONT EXTENDING FROM ONTARIO TO THE SOUTHERN U.S.
MODELS ARE INDICATING A NARROW BUT WELL-DEFINED PLUME OF MOISTURE
ALONG THE ENTIRE LENGTH OF THAT FRONT. LATEST INITIALIZATION SEEMS
TO BE FAVORING THE SLIGHTLY FASTER GFS OVER THE EURO...WHICH BRINGS
PRECIP INTO WESTERN PORTIONS OF FORECAST AREA BY SATURDAY NIGHT.
INITIALIZATION WAS ALSO TRENDING TOWARD LIKELY POPS FOR SUNDAY... SO
DECIDED TO BE AGGRESSIVE WITH POPS DUE TO SUFFICIENT LIFT ALONG AND
AHEAD OF FRONT. TEMPS WILL CLIMB BACK INTO THE LOW 80S ON
SATURDAY...BUT WILL QUICKLY PLUMMET CLOSER TO NORMAL IN WAKE OF THE
AFOREMENTIONED COLD FRONT.
&&
.AVIATION /DISCUSSION FOR THE 25/0000Z TAF ISSUANCE/...
ISSUED AT 612 PM EDT TUE SEP 24 2013
ASIDE FROM THE POTENTIAL FOR SOME MVFR OR WORSE FOG AT HUF AND
BMG...PRETTY GOOD CONFIDENCE IN VFR THROUGH THE TAF PERIOD AS A LOW
PRESSURE SYSTEM DROPS SOUTHEAST ACROSS THE MIDDLE MISSISSIPPI AND
TENNESSEE VALLEYS. ALSO...KEPT VCSH IN AT THOSE SITES AS THERE WILL
BE BETTER MOISTURE AND LIFT THERE ASSOCIATED WITH THE LOW PRESSURE
SYSTEM.
WINDS WILL BE EAST AND NORTHEAST 7 KNOTS OR LESS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH/NIELD
SHORT TERM...JH
LONG TERM....TDUD
AVIATION...MK
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
239 PM MDT MON SEP 23 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 239 PM MDT MON SEP 23 2013
UPPER FLOW WILL BE NORTHWEST TONIGHT AND TUESDAY AS THE UPPER LOW
MOVES NORTHEAST INTO IOWA. SURFACE HIGH PRESSURE WILL MOVE INTO THE
CENTRAL PLAINS.
AS THE UPPER LOW LIFTS OUTS THIS EVENING ANY REMAINING SHOWERS WILL
EXIT THE FA. SUBSIDENCE WILL FOLLOW AND CONTINUE THROUGH TUESDAY.
OTHER THAN SOME SLIGHT CHANCE POPS EARLY THIS EVENING, POPS WILL BE
NIL FOR THE REMAINDER OF THIS PART OF THE FORECAST.
HRRR AND RUC MODELS INDICATE STRONG WINDS WILL CONTINUE UNTIL AROUND
01Z. PLAN TO CONTINUE HIGH WIND WARNING AND WIND ADVISORY UNTIL 01Z
TUESDAY. GUSTY NORTHWEST WIND WILL DECREASE AROUND SUNSET.
MIN TEMPERATURES WILL BE COOL TONIGHT WITH READINGS RANGING FROM THE
MID 40S IN EASTERN COLORADO TO AROUND 50 IN THE EASTERN FA. MAX
TEMPERATURES TUESDAY WILL WARM INTO THE MID/UPPER 70S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 239 PM MDT MON SEP 23 2013
A BRIEF PERIOD OF SHORTWAVE RIDGING WILL CONTINUE TUESDAY NIGHT INTO
WEDNESDAY...LEADING TO DRY WEATHER. AS STATED ABOVE...BRIEF IS THE
KEY WORD AS THE NEXT LARGE TROUGH OF LOW PRESSURE DEVELOPS OVER THE
WESTERN UNITED STATES AND HEADS EAST. AHEAD OF THE UPPER LEVEL
TROUGH...A WARMING TREND IS FORECAST UNDER A WARM AIR ADVECTION
REGIME OF SOUTH WINDS. HIGH TEMPERATURES ARE EXPECTED TO CLIMB INTO
THE MID 80S ON WEDNESDAY AND MID TO UPPER 80S...POSSIBLY NEAR
90...ON THURSDAY. ALSO...PRESSURE GRADIENTS ARE EXPECTED TO TIGHTEN
ON WEDNESDAY WHICH WILL RESULT IN A PERIOD OF BREEZY TO POSSIBLY
WINDY CONDITIONS DURING THE DAY AND EARLY EVENING. A LEE TROUGH IS
INDICATED BY MODELS TO MOVE IN ON THURSDAY...BRINGING A WIND SHIFT
AND COOLER TEMPERATURES TO NORTHEAST COLORADO. AHEAD OF THE LEE
TROUGH...IT IS POSSIBLE A FEW SHOWERS...POSSIBLY A
THUNDERSTORM...COULD DEVELOP FOR THURSDAY AFTERNOON AND THURSDAY
NIGHT.
AS THE UPPER LEVEL TROUGH EJECTS ACROSS THE NORTHERN PLAINS...A COLD
FRONT WILL BE FORCED DOWN ACROSS THE TRI-STATE AREA. THERE ARE SOME
LARGE TIMING DIFFERENCES BETWEEN MODELS AT THE PRESENT
TIME...LEADING TO WIND AND TEMPERATURE FIELDS LACKING IN AGREEMENT
AS WELL. THEREFORE...DID NOT STRAY TOO MUCH FROM THE MIDDLE GROUND
OF THE MODELS FOR THIS NEXT SYSTEM. THE MIDDLE GROUND PLACES FRONTAL
PASSAGE EARLY IN THE DAY ON FRIDAY. EITHER WAY...THERE WILL BE
A GOOD CHANCE FOR SHOWERS AND POSSIBLY A FEW RUMBLES OF THUNDER FOR
FRIDAY NIGHT BEHIND THE FRONT. A FEW ISOLATED SHOWERS AND STORMS ARE
POSSIBLE AHEAD OF THE FRONT BUT THE MAJORITY OF THE ACTIVITY SHOULD
STAY TO THE SOUTHEAST WHERE INSTABILITY IS PROJECTED TO BE HIGHER.
IN ADDITION...TEMPERATURES COOL DRAMATICALLY AGAIN BEHIND THE COLD
FRONT. HIGH TEMPERATURES ON FRIDAY WILL RANGE FROM THE LOW 60S TO
THE UPPER 70S FROM NORTHWEST TO SOUTHEAST. COOL...NEAR TO JUST BELOW
NORMAL TEMPERATURES WILL CONTINUE INTO THE WEEKEND AS SURFACE HIGH
PRESSURE BUILDS IN FROM THE WEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1149 AM MDT MON SEP 23 2013
UPPER LOW WILL BRING SHOWERS AND ISOLATED THUNDERSTORMS INTO KGLD
AND KMCK THIS AFTERNOON. SOME MVFR CONDITIONS WILL BE POSSIBLE
WITH THE SHOWERS. THE LOW WILL QUICKLY MOVE OUT BY EVENING WITH
VFR CONDITIONS AND LIGHTER WINDS PREVAILING OVERNIGHT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WIND ADVISORY UNTIL 7 PM MDT /8 PM CDT/ THIS EVENING FOR KSZ001-
013-014-027-028-041-042.
HIGH WIND WARNING UNTIL 7 PM MDT /8 PM CDT/ THIS EVENING FOR
KSZ013-027-028-041-042.
CO...WIND ADVISORY UNTIL 7 PM MDT THIS EVENING FOR COZ090>092.
HIGH WIND WARNING UNTIL 7 PM MDT THIS EVENING FOR COZ091-092.
NE...NONE.
&&
$$
SHORT TERM...FS
LONG TERM...RRH
AVIATION...FS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1211 PM CDT Mon Sep 23 2013
.SHORT TERM...(Today and Tonight)
Issued at 302 AM CDT MON SEP 23 2013
Water vapor imagery as of 07z depicts the center of the strong upper
shortwave trough across southern Colorado shifting eastward.
Meanwhile an abundant amount of subsidence ahead of the wave was
noted. A frontal boundary stretched across the northern Gulf is
responsible in blocking moisture from spreading northward into the
region. At the surface, observations depict the surface trough
positioned across eastern Colorado with gusty southerly winds
stretching into western Kansas.
As the above mentioned upper wave lifts northeast into the central
plains Monday afternoon, the surface low edges into western Kansas,
gradually increasing southerly wind speeds between 20 and 25 mph
this afternoon. Gusts over 35 mph are expected as deeper mixing and
dry air aloft restrains dewpoints to the low 50s. Daytime heating
combined with convergence along and ahead of a weak cold front
shifting east may trigger scattered convection this afternoon and
evening. The recent runs of the HRRR and 4-KM ARW support this
thinking as north central areas stand to see the best chance of
precipitation. While speed shear is prevalent at 50 kts up to 6 Km,
uncertainty exists as to if the updrafts are able to maintain
themselves and reach the CWA border. Weak instability, mid level
lapse rates around 5-6 degrees C/Km, and meager moisture in place
can only warrant a slight chance mention of showers with perhaps an
isolated thunderstorm through this evening. The upper trough and
precipitation lifts out of the area overnight as the frontal
boundary and associated cloud cover passes through the area dry.
Expect highs today similar to previous afternoons with readings
generally in the upper 70s. By this evening, increasing insulation
from cloud cover and gusty southerly winds will boost low
temperatures a few degrees into the middle 50s.
.LONG TERM...(Tuesday through Sunday)
Issued at 302 AM CDT MON SEP 23 2013
Tuesday through Thursday continues to look dry as forcing from
upper trough moves east of the area and ridging develops. Models
show some weak cold air advection through part of the day
Tuesday. There is also better agreement on some higher 850MB RH
hanging in on the back side of the departing system implying skies
could be partly cloudy over eastern KS. Because of the cooler air
advecting south and east and the potential for a little more
clouds, have trended highs for Tuesday down a degree or two. By
Wednesday morning, skies could clear out with winds becoming light
and variable as a weak surface ridge axis passes over eastern KS
setting up conditions for good radiational cooling. Because of
this have also trended lows Wednesday morning down with some
readings potentially nearing 50. By Thursday the models are in
good agreement that southerly return flow will have begun with
better moisture advecting north. Therefore Highs in the 80s and
lows in the 60s appear reasonable.
For Thursday night through Saturday, the models remain in good
agreement with the overall synoptic pattern with only some slight
timing differences in the frontal passage. However it looks like
the most likely timing is for the front to move through late
Friday night and Saturday morning. If models continue to converge
on this solution, later shifts may want to increase pops to
likely as there appears to be plenty of moisture with modest
instability for the front to come through and lift. With the front
expected to remain north of the area most of the day Friday, temps
are expected to remain above normal with readings in the 80s.
Saturday looks to see the bulk of the cool down as cold air
advection increases through the day.
Precip should be all but over Saturday evening as the front is
progged to be into southeast KS and southern MO. Central and
eastern KS should see clearing skies into Sunday as a modified
pacific surface ridge builds into the plains and mid level heights
gradually rise. WPC tends to favor the more amplified pattern of
the ECMWF for the end of the weekend with a closed low eventually
developing to the east. This will likely keep Fall like temps for
the forecast area on Sunday.
&&
.AVIATION...(For the 18Z TAFs through 18Z Tuesday Afternoon)
Issued at 1205 PM CDT MON SEP 23 2013
Expect VFR conditions through the next 24 hours. Southerly winds
of 14 to 19 KTS with gusts of 23 to 28 KTS will diminish towards
sunset. A wind shift to the northwest will occur between 12Z and
15Z at the terminals. There may be a brief period of SCT-BKN MVFR
ceilings through the mid and late morning hours of Tuesday.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Bowen
LONG TERM...Wolters
AVIATION...Gargan
AREA FORECAST DISCUSSION
NWS TOPEKA KS
630 AM CDT Mon Sep 23 2013
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 302 AM CDT MON SEP 23 2013
Water vapor imagery as of 07z depicts the center of the strong upper
shortwave trough across southern Colorado shifting eastward.
Meanwhile an abundant amount of subsidence ahead of the wave was
noted. A frontal boundary stretched across the northern Gulf is
responsible in blocking moisture from spreading northward into the
region. At the surface, observations depict the surface trough
positioned across eastern Colorado with gusty southerly winds
stretching into western Kansas.
As the above mentioned upper wave lifts northeast into the central
plains Monday afternoon, the surface low edges into western Kansas,
gradually increasing southerly wind speeds between 20 and 25 mph
this afternoon. Gusts over 35 mph are expected as deeper mixing and
dry air aloft restrains dewpoints to the low 50s. Daytime heating
combined with convergence along and ahead of a weak cold front
shifting east may trigger scattered convection this afternoon and
evening. The recent runs of the HRRR and 4-KM ARW support this
thinking as north central areas stand to see the best chance of
precipitation. While speed shear is prevalent at 50 kts up to 6 Km,
uncertainty exists as to if the updrafts are able to maintain
themselves and reach the CWA border. Weak instability, mid level
lapse rates around 5-6 degrees C/Km, and meager moisture in place
can only warrant a slight chance mention of showers with perhaps an
isolated thunderstorm through this evening. The upper trough and
precipitation lifts out of the area overnight as the frontal
boundary and associated cloud cover passes through the area dry.
Expect highs today similar to previous afternoons with readings
generally in the upper 70s. By this evening, increasing insulation
from cloud cover and gusty southerly winds will boost low
temperatures a few degrees into the middle 50s.
.LONG TERM...(Tuesday through Sunday)
Issued at 302 AM CDT MON SEP 23 2013
Tuesday through Thursday continues to look dry as forcing from
upper trough moves east of the area and ridging develops. Models
show some weak cold air advection through part of the day
Tuesday. There is also better agreement on some higher 850MB RH
hanging in on the back side of the departing system implying skies
could be partly cloudy over eastern KS. Because of the cooler air
advecting south and east and the potential for a little more
clouds, have trended highs for Tuesday down a degree or two. By
Wednesday morning, skies could clear out with winds becoming light
and variable as a weak surface ridge axis passes over eastern KS
setting up conditions for good radiational cooling. Because of
this have also trended lows Wednesday morning down with some
readings potentially nearing 50. By Thursday the models are in
good agreement that southerly return flow will have begun with
better moisture advecting north. Therefore Highs in the 80s and
lows in the 60s appear reasonable.
For Thursday night through Saturday, the models remain in good
agreement with the overall synoptic pattern with only some slight
timing differences in the frontal passage. However it looks like
the most likely timing is for the front to move through late
Friday night and Saturday morning. If models continue to converge
on this solution, later shifts may want to increase pops to
likely as there appears to be plenty of moisture with modest
instability for the front to come through and lift. With the front
expected to remain north of the area most of the day Friday, temps
are expected to remain above normal with readings in the 80s.
Saturday looks to see the bulk of the cool down as cold air
advection increases through the day.
Precip should be all but over Saturday evening as the front is
progged to be into southeast KS and southern MO. Central and
eastern KS should see clearing skies into Sunday as a modified
pacific surface ridge builds into the plains and mid level heights
gradually rise. WPC tends to favor the more amplified pattern of
the ECMWF for the end of the weekend with a closed low eventually
developing to the east. This will likely keep Fall like temps for
the forecast area on Sunday.
&&
.AVIATION...(For the 12Z TAFs through 12Z Tuesday Morning)
Issued at 548 AM CDT MON SEP 23 2013
VFR conditions through most of the forecast period for KTOP/KFOE/KMHK.
Light and vrb winds this morning increase aft 15z with southerly
speeds sustained near 16 kts at KTOP/KFOE and 20 kts at KMHK. Wind
gusts aoa 24 kts are common through 0z. Winds back to southeast
and weaken below 10 kts aft 0z. High clouds increase in advance of
a weak cold front impacting KMHK aft 08z as light winds veer to
the west. Any developing showers or thunder should remain north of
terminals with little confidence to mention attm. A few short term
guidance tries to bring MVFR cigs to KMHK aft 08z. Will leave at
VFR and evaluate at next issuance. Front impacts KTOP/KFOE beyond
forecast period.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Bowen
LONG TERM...Wolters
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS TOPEKA KS
302 AM CDT Mon Sep 23 2013
.SHORT TERM...(Today and Tonight)
Issued at 302 AM CDT MON SEP 23 2013
Water vapor imagery as of 07z depicts the center of the strong upper
shortwave trough across southern Colorado shifting eastward.
Meanwhile an abundant amount of subsidence ahead of the wave was
noted. A frontal boundary stretched across the northern Gulf is
responsible in blocking moisture from spreading northward into the
region. At the surface, observations depict the surface trough
positioned across eastern Colorado with gusty southerly winds
stretching into western Kansas.
As the above mentioned upper wave lifts northeast into the central
plains Monday afternoon, the surface low edges into western Kansas,
gradually increasing southerly wind speeds between 20 and 25 mph
this afternoon. Gusts over 35 mph are expected as deeper mixing and
dry air aloft restrains dewpoints to the low 50s. Daytime heating
combined with convergence along and ahead of a weak cold front
shifting east may trigger scattered convection this afternoon and
evening. The recent runs of the HRRR and 4-KM ARW support this
thinking as north central areas stand to see the best chance of
precipitation. While speed shear is prevalent at 50 kts up to 6 Km,
uncertainty exists as to if the updrafts are able to maintain
themselves and reach the CWA border. Weak instability, mid level
lapse rates around 5-6 degrees C/Km, and meager moisture in place
can only warrant a slight chance mention of showers with perhaps an
isolated thunderstorm through this evening. The upper trough and
precipitation lifts out of the area overnight as the frontal
boundary and associated cloud cover passes through the area dry.
Expect highs today similar to previous afternoons with readings
generally in the upper 70s. By this evening, increasing insulation
from cloud cover and gusty southerly winds will boost low
temperatures a few degrees into the middle 50s.
.LONG TERM...(Tuesday through Sunday)
Issued at 302 AM CDT MON SEP 23 2013
Tuesday through Thursday continues to look dry as forcing from
upper trough moves east of the area and ridging develops. Models
show some weak cold air advection through part of the day
Tuesday. There is also better agreement on some higher 850MB RH
hanging in on the back side of the departing system implying skies
could be partly cloudy over eastern KS. Because of the cooler air
advecting south and east and the potential for a little more
clouds, have trended highs for Tuesday down a degree or two. By
Wednesday morning, skies could clear out with winds becoming light
and variable as a weak surface ridge axis passes over eastern KS
setting up conditions for good radiational cooling. Because of
this have also trended lows Wednesday morning down with some
readings potentially nearing 50. By Thursday the models are in
good agreement that southerly return flow will have begun with
better moisture advecting north. Therefore Highs in the 80s and
lows in the 60s appear reasonable.
For Thursday night through Saturday, the models remain in good
agreement with the overall synoptic pattern with only some slight
timing differences in the frontal passage. However it looks like
the most likely timing is for the front to move through late
Friday night and Saturday morning. If models continue to converge
on this solution, later shifts may want to increase pops to
likely as there appears to be plenty of moisture with modest
instability for the front to come through and lift. With the front
expected to remain north of the area most of the day Friday, temps
are expected to remain above normal with readings in the 80s.
Saturday looks to see the bulk of the cool down as cold air
advection increases through the day.
Precip should be all but over Saturday evening as the front is
progged to be into southeast KS and southern MO. Central and
eastern KS should see clearing skies into Sunday as a modified
pacific surface ridge builds into the plains and mid level heights
gradually rise. WPC tends to favor the more amplified pattern of
the ECMWF for the end of the weekend with a closed low eventually
developing to the east. This will likely keep Fall like temps for
the forecast area on Sunday.
&&
.AVIATION...(For the 06Z TAFs through 06Z Monday Night)
Issued at 1138 PM CDT SUN SEP 22 2013
Will keep current VFR forecast. May see a decrease in winds toward
the end of the forecast period and an outside chance for a VCTS
near MHK but too early to put in forecast.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...Bowen
LONG TERM...Wolters
AVIATION...67
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
405 PM EDT MON SEP 23 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 405 PM EDT MON SEP 23 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A MID LEVEL RIDGE OVER THE
WRN GREAT LAKES. UPSTREAM...A WELL-DEFINED MID LEVEL LOW WAS LIFTING
NE THRU WRN NEBRASKA. ALTHOUGH THE SFC HIGH PRES RIDGE IS EAST OF
THE AREA...EXTENDING FROM JAMES BAY TO LAKE HURON...STUBBORN
STRATOCU REMAINS DOWNWIND OF LAKE MICHIGAN...THOUGH THERE ARE SIGNS
THAT COVERAGE IS STARTING TO SHRINK DUE TO A COMBINATION OF FALLING
INVERSION HEIGHTS (PER RAOBS TRENDS) AND DAYTIME HEATING MIXING OUT
LOW-LEVEL MOISTURE. WARMING AIR MASS IS ALSO DIMINISHING THE LAKE
COMPONENT TO CLOUD COVER. ABUNDANT SUNSHINE HAS HELPED TO RAISE
TEMPS INTO MID 60S THIS AFTN OVER THE W HALF OF UPPER MI.
ALTHOUGH A WELL-DEFINED SHORTWAVE IS OVER THE WRN PLAINS...SHORT
TERM AND THE NEXT SEVERAL DAYS WILL BE QUIET WEATHER WISE. MAIN FCST
CONCERN WILL BE CLOUD COVER. WITH STRATOCU COVERAGE NEAR LAKE
MICHIGAN SHOWING SIGNS OF SHRINKING...THERE IS HOPE THAT THE CLOUDS
WILL CONTINUE TO DISSIPATE AND NOT REDEVELOP/EXPAND TONIGHT...
ESPECIALLY SINCE INVERSION BASE TEMPS OVER NRN LAKE MICHIGAN WILL BE
A COUPLE OF C HIGHER TONIGHT THAN LAST NIGHT. HOWEVER...SINCE
TRAJECTORIES LEAD SSE BACK TO THE STRATOCU/MOISTURE FIELD OVER SRN
LWR MI/NRN OH...STRATOCU PROBABLY WON`T CLEAR OUT FOR THE ENTIRE
NIGHT. THERE MAY BE A PERIOD THIS EVENING WHEN MUCH OF THE CLOUD
COVER DISSIPATES...BUT EXPECT SOME INCREASE IN STRATOCU AGAIN
OVERNIGHT GIVEN UPSTREAM CLOUD COVER/MOISTURE AS MENTIONED AND DUE
TO LAND BREEZE CONVERGENCE DEVELOPING OVER LAKE MICHIGAN. CLOUDS
SHOULDN`T BE AS EXTENSIVE LATE TONIGHT/TUE MORNING AS EARLIER TODAY.
AS FOR TEMPS...GENERALLY FAVORED THE LOW END OF GUIDANCE WITH
PRECIPITABLE WATER 50-60PCT OF NORMAL AND WEAKER PRES
GRADIENT/LOW-LEVEL WINDS LATER TONIGHT THAN EARLY THIS MORNING. WITH
MINS DOWN INTO THE MID 30S IN THE INTERIOR...EXPECT PATCHY FROST
OVERNIGHT.
MODELS ARE IN GOOD AGREEMENT TAKING THE CURRENTLY WELL-DEFINED MID
LOW OVER NEBRASKA E INTO THE MID MISSISSIPPI VALLEY TUE AND
WEAKENING IT AS IT CUTS INTO THE MID LEVEL RIDGE. FEATURE WILL HAVE
NO AFFECT ON THE WEATHER HERE TUE AS DRY AIR LINGERS OVER THE AREA.
AS WITH TONIGHT...MAIN CONCERN TUE WILL BE STRATOCU NEAR LAKE MI.
STRATOCU DOWNWIND OF THE LAKE MAY BRIEFLY EXPAND WESTWARD FOR A
COUPLE OF HRS TUE MORNING AS DAYTIME HEATING WORKS ON LOW-LEVEL
MOISTURE...BUT THERE SHOULD BE A SOMEWHAT QUICKER EROSION OF THE
CLOUDS FROM INLAND TOWARD THE LAKE THAN TODAY. OTHER THAN THE CLOUD
ISSUE...TUE IS SHAPING UP TO BE A NICE AUTUMN DAY. IF MIXING REACHES
850MB...MAX TEMPS IN THE LOW/MID 70S WOULD BE COMMON. MIXING DEPTH
MAY NOT GET QUITE THAT HIGH...SO UPPER 60S/LWR 70S LOOK MORE LIKELY
AWAY FROM MARINE INFLUENCE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 249 PM EDT MON SEP 23 2013
WILL START THE PERIOD AT 00Z WEDNESDAY WITH THE 500MB RIDGE STILL
SET UP ACROSS E UPPER MI AND LAKE HURON/E ONTARIO. THE MAIN STORY
WILL BE THE CONTINUALLY WEAKENING TROUGH STRETCHING FROM MN THROUGH
NW TN. A HIGHLY BROKEN LINE OF SHOWERS MAY BE SET UP ACROSS MN...BUT
WITH THE WEAKENING OF THE TROUGH AND SFC HIGH WITH LIGHT NE FLOW AT
THE SFC...LITTLE MORE THAN CLOUDS ARE ANTICIPATED ACROSS UPPER MI
LATE TUESDAY NIGHT INTO WEDNESDAY MORNING. BEHIND THE 500MB
TROUGH...THE S-CENTRAL PLAINS RIDGE WILL QUICKLY BUILD BACK ACROSS
THE UPPER GREAT LAKES WEDNESDAY THROUGH THURSDAY.
LOOK FOR STRONGER SW FLOW TO TAKE OVER ALOFT AT AT THE SFC THURSDAY
NIGHT THROUGH FRIDAY NIGHT...AHEAD OF THE NEARING TROUGH TO OUT W.
COOLER AIRMASS IS ON THE WAY FOR THE WEEKEND. WE CAN GET A GLIMPSE
OF WHAT IS TO COME BY LOOKING AT THE 00Z SATURDAY 850MB TEMPS ACROSS
THE REGION. 850MB TEMPS WILL LIKELY RANGE FROM 14-16Z ACROSS UPPER
MI...WHILE A MUCH COOLER 4-6C ACROSS NW ND. ONLY MINIMAL TS
POTENTIAL ALONG THE FRONT...GIVEN ITS NOCTURNAL PASSAGE OVER THE W
CWA SATURDAY MORNING. THERE ARE ENOUGH SIGNIFICANT DIFFERENCES
BETWEEN THE ECMWF AND GFS AT THIS POINT TO GO WITH A CONSENSUS
SOLUTION. THE 23/12Z RUN OF THE GFS IS AROUND 6HRS FASTER THAN THE
23/00Z ECMWF WITH THE PASSAGE OF THE SHORTWAVE. STILL...THEY ARE
STARTING TO COME TO A BETTER AGREEMENT WHEN COMPARED TO THE MUCH
QUICKER 23/06Z RUN OF THE GFS.
THE ENTIRE SYSTEM LOOKS TO MODERATE QUITE A BIT...WITH THE COOLEST
AIR FILTERING INTO UPPER MI BEING AROUND 5-7C SATURDAY NIGHT THROUGH
MONDAY MORNING. AS AN ASIDE...THE 23/12Z RUN OF THE GFS ONLY HAS
850MB TEMPS COOLING TO AROUND 10C. MUCH OF THIS IS DUE TO THE
DIFFERENCE IN THE HANDLING OF THE MID-UPPER LEVEL WAVE. THE ECMWF IS
PERSISTENT IN HAVING THE TROUGH OVER THE UPPER GREAT LAKES THIS
WEEKEND CUT OFF FROM THE MAIN W-E FLOW AND FORM A LOW
OVERHEAD...BEFORE DROPPING IT INTO THE MID MS VALLEY THROUGH THE
MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 127 PM EDT MON SEP 23 2013
VFR CONDITIONS SHOULD PREVAIL AT KIWD/KCMX/KSAW THRU THIS FCST
PERIOD UNDER A GENERALLY DRY AIR MASS ASSOCIATED WITH HIGH PRES OVER
ONTARIO/WRN QUEBEC. HOWEVER...THERE IS SOME CONCERN THAT LOW CLOUDS
COULD DEVELOP AT KSAW LATE TONIGHT UNDER SSE UPSLOPE FLOW OFF LAKE
MICHIGAN. SINCE CURRENT DWPTS OVER NRN LAKE MICHIGAN AREN`T
SIGNIFICANTLY HIGHER THAN EXPECTED MIN TEMPS TONIGHT...WILL HOLD OFF
ON INCLUDING A LOW MVFR OR EVEN IFR CIG AT KSAW FOR NOW. WILL BE
SOMETHING TO MONITOR. UNDER TIGHTER PRES GRADIENT...MARGINAL LLWS IS
EXPECTED AT KIWD TONIGHT AS WINDS INCREASE ABOVE NOCTURNAL
INVERSION.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 PM EDT MON SEP 23 2013
SLOW MOVING WEATHER PATTERN THIS WEEK WILL FEATURE HIGH PRES TO THE
E AND LOW PRES TO THE W. EVENTUALLY...A LOW PRES SYSTEM WILL MOVE NE
TO HUDSON BAY LATE WEEK WITH ASSOCIATED COLD FRONT PASSING ACROSS
LAKE SUPERIOR SAT. THRU THE WEEK...RELATIVELY WEAK PRES GRADIENT
WILL RESULT IN WINDS MOSTLY UNDER 20KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1241 PM EDT MON SEP 23 2013
.SYNOPSIS...
ISSUED AT 249 AM EDT MON SEP 23 2013
HIGH PRESSURE WILL BRING AN EXTENDED PERIOD OF DRY WEATHER AND
MOSTLY CLEAR SKIES THROUGH THE WORK WEEK. HIGH TEMPERATURES WILL
SLOWLY MODERATE...WITH READINGS WELL ABOVE NORMAL WEDNESDAY THROUGH
SATURDAY. OVERNIGHT LOWS WILL BE COOL...AND FROST REMAINS A
POSSIBILITY IN MANY AREAS AGAIN TONIGHT.
&&
.UPDATE...
ISSUED AT 1240 PM EDT MON SEP 23 2013
15Z COMPOSITE ANALYSIS SHOWS A 1024MB HIGH OVER NORTHEAST ONTARIO...
WITH SHARP MID/UPPER LEVEL RIDGING SPANNING THE LENGTH OF THE
MISSISSIPPI VALLEY. OVERALL AIR MASS IS QUITE DRY WITH 12Z APX
SOUNDING PRECIPITABLE WATER OF 0.35 INCH...BUT SHALLOW INSTABILITY
OVER LAKES MICHIGAN/HURON (WITH WELL DEFINED LAND BREEZE BOUNDARY
OUT OVER LAKE HURON) PRODUCING CLOUDS ACROSS NORTHEAST LOWER AND
PARTS OF EASTERN UPPER...SOME OF WHICH ARE BEING ENHANCED BY THE
DIURNAL HEATING CYCLE. SKIES OVER NORTHWEST LOWER WERE SUNNY.
DEEP LAYER RIDGING GOING NOWHERE FAST THIS AFTERNOON. CLOUDS ACROSS
EASTERN UPPER/NORTHEAST LOWER EXPECTED TO GRADUALLY MIX OUT WITH
TIME...HAVE MADE SOME ADJUSTMENT TO SKY COVER ESPECIALLY ACROSS
EASTERN UPPER. MIXING 12Z APX SOUNDING TO 850MB YIELDS AN AFTERNOON
HIGH OF 62F...SO AROUND 60-MID 60S SHOULD WORK MOST AREAS.
UPDATE ISSUED AT 804 AM EDT MON SEP 23 2013
UPDATE TO EXPIRE FROST/FREEZE HEADLINES.
UPDATE ISSUED AT 713 AM EDT MON SEP 23 2013
CLOUD COVER HAS EXPANDED A BIT FURTHER INTO NE LOWER MI...THOUGH
THAT EXPANSION HAS STALLED OVER THE LAST 60-90MIN. THIS PROMISES
ADDITIONAL EROSION...ESPECIALLY AS THE SUN GOES TO WORK.
STILL...HAVE TENDED TO SLOW DOWN CLEARING TRENDS THIS MORNING.
OTHER AREAS IMPACTED BY AT LEAST PARTLY CLOUDY CONDITIONS THIS
MORNING INCLUDE WESTERN MACK AND FAR WESTERN CHIP...AND
GLADWIN/ARENAC COUNTIES.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 249 AM EDT MON SEP 23 2013
LARGE CANADIAN HIGH PRESSURE SLIDES INTO THE EASTERN LAKES THROUGH
TONIGHT WITH DEVELOPING WEAK RETURN FLOW ACROSS NORTHERN
MICHIGAN. SENSIBLE WEATHER CONCERNS IN THE SHORT TERM FOCUSED
PRIMARILY ON CLOUD TRENDS AND MIN TEMPERATURES TONIGHT.
TODAY...LOW LEVEL FLOW VEERS SOUTHEAST ON WESTERN PERIPHERY OF HIGH
PRESSURE WITH STRENGTHENING WARM AIR ADVECTION PUSHING H8
TEMPERATURES INTO THE +7C TO +9C RANGE. BRINGING THESE TEMPS DOWN
DRY ADIABATICALLY YIELDS HIGHS IN THE UPPER 50S TO MID 60S
/WARMEST WEST/. TRICKY CLOUD FORECAST WITH PLENTY OF RESIDUAL LOW
LEVEL MOISTURE ALONG THE LAKE HURON COAST/SAGINAW BAY TRAPPED
BENEATH SUBSIDENCE INVERSION WITH FAVORABLE DELTA T/S AND WEAK
ONSHORE FLOW. THE RUC 925-850MB RH FIELDS SHOW THESE LOWER CLOUDS
PLAGUING LAKE HURON COASTAL AREAS FROM ALPENA SOUTHWARD TOWARD SAGINAW
BAY THROUGH THE MORNING HOURS. AS DELTA T/S DECREASE WITH WARMING
ALOFT AND MUCH DRIER AIR WORKS INTO THE AREA /PWATS AROUND
0.4/...THE CLOUDS SHOULD /HOPEFULLY/ DISSIPATE. AS IS FREQUENTLY
THE CASE THIS TIME OF YEAR WITH REGARD TO LOW CLOUDS...WOULD NOT
BE SURPRISED IF THEY ENDED UP MORE PERSISTENT THAN CURRENTLY
FORECAST.
TONIGHT...ANOTHER POTENTIAL FROSTY NIGHT FOR PORTIONS OF THE AREA.
EXCELLENT RADIATIONAL COOLING SCENARIO ONCE AGAIN WITH CLEAR SKIES
AND LIGHT WINDS. SEE LITTLE REASON WHY LOW TEMPS WILL NOT DIP INTO
THE MIDDLE 30S OVER PORTIONS OF NORTHERN LOWER /ESPECIALLY EAST OF
I-75/...WITH SOME READINGS LIKELY INTO THE LOWER 30S IN THE
TYPICALLY COLDER LOCATIONS. WILL "BEEF UP" THE FROST WORDING IN
THE HWO...BUT WILL LEAVE HEADLINE DECISIONS TO THE DAY SHIFT BASED
ON LATEST OBS/MODEL TRENDS. AREAS OF FOG ALSO LIKELY...PARTICULARLY
IN THE COLDER VALLEY LOCATIONS AND AROUND INLAND LAKES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 249 AM EDT MON SEP 23 2013
A SPECTACULAR WORK WEEK IS AHEAD (HARD TO IMAGINE A MULTI-DAY
STRETCH WITH QUIETER LONG-TERM FORECASTS THAN THE LAST FEW). THE ONE
INCOMING SYSTEM OF ANY NOTE IS A VIGOROUS SHORTWAVE IN THE 4-CORNERS
REGION EARLY THIS MORNING. THIS SYSTEM WILL EMERGE INTO THE CENTRAL
PLAINS TODAY...BUT THEN ENCOUNTER A BLOCKED PATTERN TO THE EAST...
WITH A STALLED UPPER LOW OVER NEW BRUNSWICK AND RIDGING IN THE
LAKES. THE INCOMING WAVE/S SOLUTION TO THIS PROBLEM IS CUT
UNDERNEATH THE RIDGE...MOVING THRU THE OHIO VALLEY ON WEDNESDAY.
THAT WILL BE TOO FAR SOUTH TO HAVE MUCH IMPACT ON US. THAT LEAVES
TEMPS AS THE ONLY CONCERN OF NOTE.
TUESDAY INTO WEDNESDAY...500MB RIDGING...WHICH IS OVERHEAD TO START
TUE MORNING...WILL DRIFT EAST TO LAKE HURON THRU TUE NIGHT. AS THE
UPPER LOW PASSES TO OUR SOUTH...THAT RIDGE WILL BE DISRUPTED...BUT
RIDGING WILL BEGIN TO FOLD OVER TOP OF THE LOW AND POKE IN FROM THE
SW ON WEDNESDAY. AT THE SURFACE...HIGH PRESSURE WILL BE A SEMI-
PERMANENT FEATURE IN THE VICINITY OF LAKE HURON. THIS PERSISTENT
RIDGING SURFACE AND ALOFT WILL MAINTAIN DEEP SUBSIDENCE AND ABUNDANT
DRY AIR. 850-700MB RH LEVELS ARE BELOW 20 PERCENT THROUGHOUT...AND
ARE BELOW 10 PERCENT MOST OF THE TIME.
THE UPPER LOW PASSING TO OUR SOUTH WILL LIKELY FEED SOME THIN CIRRUS
OVERHEAD TUE NIGHT/WED. OTHERWISE...SKIES WILL BE CLEAR. MAX TEMPS
WILL BE MAINLY IN THE MID TO UPPER 60S BOTH DAYS...WITH A FEW 70S
POSSIBLE WEDNESDAY. MIN TEMPS 40-45 FOR MOST...BUT THE INLAND COOL
SPOTS WILL LOWER INTO THE MID/UPPER 30S.
REST OF THE FORECAST...500MB RIDGING GETS PUMPED BACK INTO THE
REGION FROM THE SW FOR THE REST OF THE WORK WEEK. THU/FRI LOOK VERY
PLEASANT AND MILD...WITH MAX TEMPS MAINLY IN THE 70S.
THE GFS REMAINS A FAST OUTLIER WHEN IT COMES TO BREAKING DOWN THE
RIDGE...AND USHERING IN OUR NEXT CHANCE FOR PRECIP. THE ECMWF HAS
BEEN MUCH MORE CONSISTENT...AND IS PREFERRED. HEIGHTS WILL BE
STEADILY ERODED THIS WEEKEND...WITH THE ACTUAL TROF AXIS ARRIVING
MOST LIKELY ON SUNDAY. THIS SUPPORTS DRY WX INTO FRIDAY NIGHT...AND
CHANCE POPS SAT THRU SUNDAY. SATURDAY WILL REMAIN WARM...WITH
READING CLOSER TO CLIMO SUNDAY.
THOUGH IT LIES BEYOND THE SCOPE OF THIS FORECAST...DIFFICULT TO TELL
HOW LONG THE UNSETTLED WX WILL LAST. 12Z ECMWF WANTED TO LINGER THE
TROF IN THE REGION LONG ENOUGH TO REINFORCE IT WITH ARCTIC
ENERGY...CARVING OUT AN UNPLEASANT UPPER LOW OVER THE LAKES REGION
NEXT WEEK. WE SHALL SEE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 713 AM EDT MON SEP 23 2013
VFR.
HIGH PRESSURE CENTERED OVER NE ONTARIO WILL DRIFT SOUTH TO LAKE
HURON OVER THE NEXT 24 HOURS. THE STILL COOL AIRMASS ASSOCIATED
WITH THE HIGH IS SUPPORTING SOME LAKE-INDUCED CLOUD COVER...
ESPECIALLY INTO NE LOWER MI (APN). THIS WILL ERODE WITH TIME TODAY
AS WE WARM. SKIES SHOULD BE CLEAR ACROSS THE AREA TONIGHT. WINDS
WILL BE LIGHT AND VARIABLE.
&&
.MARINE...
ISSUED AT 249 AM EDT MON SEP 23 2013
A LARGE AREA OF HIGH PRESSURE WILL ANCHORED ACROSS THE GREAT LAKES
FOR THE NEXT SEVERAL DAYS. WITH AN OVERALL LIGHT WIND REGIME...NO
HEADLINES ARE ANTICIPATED.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JPB
SYNOPSIS...JZ
SHORT TERM...JK
LONG TERM...JZ
AVIATION...JZ
MARINE...JK
AREA FORECAST DISCUSSION
NWS GAYLORD MI
805 AM EDT MON SEP 23 2013
.SYNOPSIS...
ISSUED AT 249 AM EDT MON SEP 23 2013
HIGH PRESSURE WILL BRING AN EXTENDED PERIOD OF DRY WEATHER AND
MOSTLY CLEAR SKIES THROUGH THE WORK WEEK. HIGH TEMPERATURES WILL
SLOWLY MODERATE...WITH READINGS WELL ABOVE NORMAL WEDNESDAY THROUGH
SATURDAY. OVERNIGHT LOWS WILL BE COOL...AND FROST REMAINS A
POSSIBILITY IN MANY AREAS AGAIN TONIGHT.
&&
.UPDATE...
ISSUED AT 804 AM EDT MON SEP 23 2013
UPDATE TO EXPIRE FROST/FREEZE HEADLINES.
UPDATE ISSUED AT 713 AM EDT MON SEP 23 2013
CLOUD COVER HAS EXPANDED A BIT FURTHER INTO NE LOWER MI...THOUGH
THAT EXPANSION HAS STALLED OVER THE LAST 60-90MIN. THIS PROMISES
ADDITIONAL EROSION...ESPECIALLY AS THE SUN GOES TO WORK.
STILL...HAVE TENDED TO SLOW DOWN CLEARING TRENDS THIS MORNING.
OTHER AREAS IMPACTED BY AT LEAST PARTLY CLOUDY CONDITIONS THIS
MORNING INCLUDE WESTERN MACK AND FAR WESTERN CHIP...AND
GLADWIN/ARENAC COUNTIES.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 249 AM EDT MON SEP 23 2013
LARGE CANADIAN HIGH PRESSURE SLIDES INTO THE EASTERN LAKES THROUGH
TONIGHT WITH DEVELOPING WEAK RETURN FLOW ACROSS NORTHERN
MICHIGAN. SENSIBLE WEATHER CONCERNS IN THE SHORT TERM FOCUSED
PRIMARILY ON CLOUD TRENDS AND MIN TEMPERATURES TONIGHT.
TODAY...LOW LEVEL FLOW VEERS SOUTHEAST ON WESTERN PERIPHERY OF HIGH
PRESSURE WITH STRENGTHENING WARM AIR ADVECTION PUSHING H8
TEMPERATURES INTO THE +7C TO +9C RANGE. BRINGING THESE TEMPS DOWN
DRY ADIABATICALLY YIELDS HIGHS IN THE UPPER 50S TO MID 60S
/WARMEST WEST/. TRICKY CLOUD FORECAST WITH PLENTY OF RESIDUAL LOW
LEVEL MOISTURE ALONG THE LAKE HURON COAST/SAGINAW BAY TRAPPED
BENEATH SUBSIDENCE INVERSION WITH FAVORABLE DELTA T/S AND WEAK
ONSHORE FLOW. THE RUC 925-850MB RH FIELDS SHOW THESE LOWER CLOUDS
PLAGUING LAKE HURON COASTAL AREAS FROM ALPENA SOUTHWARD TOWARD SAGINAW
BAY THROUGH THE MORNING HOURS. AS DELTA T/S DECREASE WITH WARMING
ALOFT AND MUCH DRIER AIR WORKS INTO THE AREA /PWATS AROUND
0.4/...THE CLOUDS SHOULD /HOPEFULLY/ DISSIPATE. AS IS FREQUENTLY
THE CASE THIS TIME OF YEAR WITH REGARD TO LOW CLOUDS...WOULD NOT
BE SURPRISED IF THEY ENDED UP MORE PERSISTENT THAN CURRENTLY
FORECAST.
TONIGHT...ANOTHER POTENTIAL FROSTY NIGHT FOR PORTIONS OF THE AREA.
EXCELLENT RADIATIONAL COOLING SCENARIO ONCE AGAIN WITH CLEAR SKIES
AND LIGHT WINDS. SEE LITTLE REASON WHY LOW TEMPS WILL NOT DIP INTO
THE MIDDLE 30S OVER PORTIONS OF NORTHERN LOWER /ESPECIALLY EAST OF
I-75/...WITH SOME READINGS LIKELY INTO THE LOWER 30S IN THE
TYPICALLY COLDER LOCATIONS. WILL "BEEF UP" THE FROST WORDING IN
THE HWO...BUT WILL LEAVE HEADLINE DECISIONS TO THE DAY SHIFT BASED
ON LATEST OBS/MODEL TRENDS. AREAS OF FOG ALSO LIKELY...PARTICULARLY
IN THE COLDER VALLEY LOCATIONS AND AROUND INLAND LAKES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 249 AM EDT MON SEP 23 2013
A SPECTACULAR WORK WEEK IS AHEAD (HARD TO IMAGINE A MULTI-DAY
STRETCH WITH QUIETER LONG-TERM FORECASTS THAN THE LAST FEW). THE ONE
INCOMING SYSTEM OF ANY NOTE IS A VIGOROUS SHORTWAVE IN THE 4-CORNERS
REGION EARLY THIS MORNING. THIS SYSTEM WILL EMERGE INTO THE CENTRAL
PLAINS TODAY...BUT THEN ENCOUNTER A BLOCKED PATTERN TO THE EAST...
WITH A STALLED UPPER LOW OVER NEW BRUNSWICK AND RIDGING IN THE
LAKES. THE INCOMING WAVE/S SOLUTION TO THIS PROBLEM IS CUT
UNDERNEATH THE RIDGE...MOVING THRU THE OHIO VALLEY ON WEDNESDAY.
THAT WILL BE TOO FAR SOUTH TO HAVE MUCH IMPACT ON US. THAT LEAVES
TEMPS AS THE ONLY CONCERN OF NOTE.
TUESDAY INTO WEDNESDAY...500MB RIDGING...WHICH IS OVERHEAD TO START
TUE MORNING...WILL DRIFT EAST TO LAKE HURON THRU TUE NIGHT. AS THE
UPPER LOW PASSES TO OUR SOUTH...THAT RIDGE WILL BE DISRUPTED...BUT
RIDGING WILL BEGIN TO FOLD OVER TOP OF THE LOW AND POKE IN FROM THE
SW ON WEDNESDAY. AT THE SURFACE...HIGH PRESSURE WILL BE A SEMI-
PERMANENT FEATURE IN THE VICINITY OF LAKE HURON. THIS PERSISTENT
RIDGING SURFACE AND ALOFT WILL MAINTAIN DEEP SUBSIDENCE AND ABUNDANT
DRY AIR. 850-700MB RH LEVELS ARE BELOW 20 PERCENT THROUGHOUT...AND
ARE BELOW 10 PERCENT MOST OF THE TIME.
THE UPPER LOW PASSING TO OUR SOUTH WILL LIKELY FEED SOME THIN CIRRUS
OVERHEAD TUE NIGHT/WED. OTHERWISE...SKIES WILL BE CLEAR. MAX TEMPS
WILL BE MAINLY IN THE MID TO UPPER 60S BOTH DAYS...WITH A FEW 70S
POSSIBLE WEDNESDAY. MIN TEMPS 40-45 FOR MOST...BUT THE INLAND COOL
SPOTS WILL LOWER INTO THE MID/UPPER 30S.
REST OF THE FORECAST...500MB RIDGING GETS PUMPED BACK INTO THE
REGION FROM THE SW FOR THE REST OF THE WORK WEEK. THU/FRI LOOK VERY
PLEASANT AND MILD...WITH MAX TEMPS MAINLY IN THE 70S.
THE GFS REMAINS A FAST OUTLIER WHEN IT COMES TO BREAKING DOWN THE
RIDGE...AND USHERING IN OUR NEXT CHANCE FOR PRECIP. THE ECMWF HAS
BEEN MUCH MORE CONSISTENT...AND IS PREFERRED. HEIGHTS WILL BE
STEADILY ERODED THIS WEEKEND...WITH THE ACTUAL TROF AXIS ARRIVING
MOST LIKELY ON SUNDAY. THIS SUPPORTS DRY WX INTO FRIDAY NIGHT...AND
CHANCE POPS SAT THRU SUNDAY. SATURDAY WILL REMAIN WARM...WITH
READING CLOSER TO CLIMO SUNDAY.
THOUGH IT LIES BEYOND THE SCOPE OF THIS FORECAST...DIFFICULT TO TELL
HOW LONG THE UNSETTLED WX WILL LAST. 12Z ECMWF WANTED TO LINGER THE
TROF IN THE REGION LONG ENOUGH TO REINFORCE IT WITH ARCTIC
ENERGY...CARVING OUT AN UNPLEASANT UPPER LOW OVER THE LAKES REGION
NEXT WEEK. WE SHALL SEE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 713 AM EDT MON SEP 23 2013
VFR.
HIGH PRESSURE CENTERED OVER NE ONTARIO WILL DRIFT SOUTH TO LAKE
HURON OVER THE NEXT 24 HOURS. THE STILL COOL AIRMASS ASSOCIATED
WITH THE HIGH IS SUPPORTING SOME LAKE-INDUCED CLOUD COVER...
ESPECIALLY INTO NE LOWER MI (APN). THIS WILL ERODE WITH TIME TODAY
AS WE WARM. SKIES SHOULD BE CLEAR ACROSS THE AREA TONIGHT. WINDS
WILL BE LIGHT AND VARIABLE.
&&
.MARINE...
ISSUED AT 249 AM EDT MON SEP 23 2013
A LARGE AREA OF HIGH PRESSURE WILL ANCHORED ACROSS THE GREAT LAKES
FOR THE NEXT SEVERAL DAYS. WITH AN OVERALL LIGHT WIND REGIME...NO
HEADLINES ARE ANTICIPATED.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...MB
SYNOPSIS...JZ
SHORT TERM...JK
LONG TERM...JZ
AVIATION...JZ
MARINE...JK
AREA FORECAST DISCUSSION
NWS GAYLORD MI
713 AM EDT MON SEP 23 2013
.SYNOPSIS...
ISSUED AT 249 AM EDT MON SEP 23 2013
HIGH PRESSURE WILL BRING AN EXTENDED PERIOD OF DRY WEATHER AND
MOSTLY CLEAR SKIES THROUGH THE WORK WEEK. HIGH TEMPERATURES WILL
SLOWLY MODERATE...WITH READINGS WELL ABOVE NORMAL WEDNESDAY THROUGH
SATURDAY. OVERNIGHT LOWS WILL BE COOL...AND FROST REMAINS A
POSSIBILITY IN MANY AREAS AGAIN TONIGHT.
&&
.UPDATE...
ISSUED AT 713 AM EDT MON SEP 23 2013
CLOUD COVER HAS EXPANDED A BIT FURTHER INTO NE LOWER MI...THOUGH
THAT EXPANSION HAS STALLED OVER THE LAST 60-90MIN. THIS PROMISES
ADDITIONAL EROSION...ESPECIALLY AS THE SUN GOES TO WORK.
STILL...HAVE TENDED TO SLOW DOWN CLEARING TRENDS THIS MORNING.
OTHER AREAS IMPACTED BY AT LEAST PARTLY CLOUDY CONDITIONS THIS
MORNING INCLUDE WESTERN MACK AND FAR WESTERN CHIP...AND
GLADWIN/ARENAC COUNTIES.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 249 AM EDT MON SEP 23 2013
LARGE CANADIAN HIGH PRESSURE SLIDES INTO THE EASTERN LAKES THROUGH
TONIGHT WITH DEVELOPING WEAK RETURN FLOW ACROSS NORTHERN
MICHIGAN. SENSIBLE WEATHER CONCERNS IN THE SHORT TERM FOCUSED
PRIMARILY ON CLOUD TRENDS AND MIN TEMPERATURES TONIGHT.
TODAY...LOW LEVEL FLOW VEERS SOUTHEAST ON WESTERN PERIPHERY OF HIGH
PRESSURE WITH STRENGTHENING WARM AIR ADVECTION PUSHING H8
TEMPERATURES INTO THE +7C TO +9C RANGE. BRINGING THESE TEMPS DOWN
DRY ADIABATICALLY YIELDS HIGHS IN THE UPPER 50S TO MID 60S
/WARMEST WEST/. TRICKY CLOUD FORECAST WITH PLENTY OF RESIDUAL LOW
LEVEL MOISTURE ALONG THE LAKE HURON COAST/SAGINAW BAY TRAPPED
BENEATH SUBSIDENCE INVERSION WITH FAVORABLE DELTA T/S AND WEAK
ONSHORE FLOW. THE RUC 925-850MB RH FIELDS SHOW THESE LOWER CLOUDS
PLAGUING LAKE HURON COASTAL AREAS FROM ALPENA SOUTHWARD TOWARD SAGINAW
BAY THROUGH THE MORNING HOURS. AS DELTA T/S DECREASE WITH WARMING
ALOFT AND MUCH DRIER AIR WORKS INTO THE AREA /PWATS AROUND
0.4/...THE CLOUDS SHOULD /HOPEFULLY/ DISSIPATE. AS IS FREQUENTLY
THE CASE THIS TIME OF YEAR WITH REGARD TO LOW CLOUDS...WOULD NOT
BE SURPRISED IF THEY ENDED UP MORE PERSISTENT THAN CURRENTLY
FORECAST.
TONIGHT...ANOTHER POTENTIAL FROSTY NIGHT FOR PORTIONS OF THE AREA.
EXCELLENT RADIATIONAL COOLING SCENARIO ONCE AGAIN WITH CLEAR SKIES
AND LIGHT WINDS. SEE LITTLE REASON WHY LOW TEMPS WILL NOT DIP INTO
THE MIDDLE 30S OVER PORTIONS OF NORTHERN LOWER /ESPECIALLY EAST OF
I-75/...WITH SOME READINGS LIKELY INTO THE LOWER 30S IN THE
TYPICALLY COLDER LOCATIONS. WILL "BEEF UP" THE FROST WORDING IN
THE HWO...BUT WILL LEAVE HEADLINE DECISIONS TO THE DAY SHIFT BASED
ON LATEST OBS/MODEL TRENDS. AREAS OF FOG ALSO LIKELY...PARTICULARLY
IN THE COLDER VALLEY LOCATIONS AND AROUND INLAND LAKES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 249 AM EDT MON SEP 23 2013
A SPECTACULAR WORK WEEK IS AHEAD (HARD TO IMAGINE A MULTI-DAY
STRETCH WITH QUIETER LONG-TERM FORECASTS THAN THE LAST FEW). THE ONE
INCOMING SYSTEM OF ANY NOTE IS A VIGOROUS SHORTWAVE IN THE 4-CORNERS
REGION EARLY THIS MORNING. THIS SYSTEM WILL EMERGE INTO THE CENTRAL
PLAINS TODAY...BUT THEN ENCOUNTER A BLOCKED PATTERN TO THE EAST...
WITH A STALLED UPPER LOW OVER NEW BRUNSWICK AND RIDGING IN THE
LAKES. THE INCOMING WAVE/S SOLUTION TO THIS PROBLEM IS CUT
UNDERNEATH THE RIDGE...MOVING THRU THE OHIO VALLEY ON WEDNESDAY.
THAT WILL BE TOO FAR SOUTH TO HAVE MUCH IMPACT ON US. THAT LEAVES
TEMPS AS THE ONLY CONCERN OF NOTE.
TUESDAY INTO WEDNESDAY...500MB RIDGING...WHICH IS OVERHEAD TO START
TUE MORNING...WILL DRIFT EAST TO LAKE HURON THRU TUE NIGHT. AS THE
UPPER LOW PASSES TO OUR SOUTH...THAT RIDGE WILL BE DISRUPTED...BUT
RIDGING WILL BEGIN TO FOLD OVER TOP OF THE LOW AND POKE IN FROM THE
SW ON WEDNESDAY. AT THE SURFACE...HIGH PRESSURE WILL BE A SEMI-
PERMANENT FEATURE IN THE VICINITY OF LAKE HURON. THIS PERSISTENT
RIDGING SURFACE AND ALOFT WILL MAINTAIN DEEP SUBSIDENCE AND ABUNDANT
DRY AIR. 850-700MB RH LEVELS ARE BELOW 20 PERCENT THROUGHOUT...AND
ARE BELOW 10 PERCENT MOST OF THE TIME.
THE UPPER LOW PASSING TO OUR SOUTH WILL LIKELY FEED SOME THIN CIRRUS
OVERHEAD TUE NIGHT/WED. OTHERWISE...SKIES WILL BE CLEAR. MAX TEMPS
WILL BE MAINLY IN THE MID TO UPPER 60S BOTH DAYS...WITH A FEW 70S
POSSIBLE WEDNESDAY. MIN TEMPS 40-45 FOR MOST...BUT THE INLAND COOL
SPOTS WILL LOWER INTO THE MID/UPPER 30S.
REST OF THE FORECAST...500MB RIDGING GETS PUMPED BACK INTO THE
REGION FROM THE SW FOR THE REST OF THE WORK WEEK. THU/FRI LOOK VERY
PLEASANT AND MILD...WITH MAX TEMPS MAINLY IN THE 70S.
THE GFS REMAINS A FAST OUTLIER WHEN IT COMES TO BREAKING DOWN THE
RIDGE...AND USHERING IN OUR NEXT CHANCE FOR PRECIP. THE ECMWF HAS
BEEN MUCH MORE CONSISTENT...AND IS PREFERRED. HEIGHTS WILL BE
STEADILY ERODED THIS WEEKEND...WITH THE ACTUAL TROF AXIS ARRIVING
MOST LIKELY ON SUNDAY. THIS SUPPORTS DRY WX INTO FRIDAY NIGHT...AND
CHANCE POPS SAT THRU SUNDAY. SATURDAY WILL REMAIN WARM...WITH
READING CLOSER TO CLIMO SUNDAY.
THOUGH IT LIES BEYOND THE SCOPE OF THIS FORECAST...DIFFICULT TO TELL
HOW LONG THE UNSETTLED WX WILL LAST. 12Z ECMWF WANTED TO LINGER THE
TROF IN THE REGION LONG ENOUGH TO REINFORCE IT WITH ARCTIC
ENERGY...CARVING OUT AN UNPLEASANT UPPER LOW OVER THE LAKES REGION
NEXT WEEK. WE SHALL SEE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 713 AM EDT MON SEP 23 2013
VFR.
HIGH PRESSURE CENTERED OVER NE ONTARIO WILL DRIFT SOUTH TO LAKE
HURON OVER THE NEXT 24 HOURS. THE STILL COOL AIRMASS ASSOCIATED
WITH THE HIGH IS SUPPORTING SOME LAKE-INDUCED CLOUD COVER...
ESPECIALLY INTO NE LOWER MI (APN). THIS WILL ERODE WITH TIME TODAY
AS WE WARM. SKIES SHOULD BE CLEAR ACROSS THE AREA TONIGHT. WINDS
WILL BE LIGHT AND VARIABLE.
&&
.MARINE...
ISSUED AT 249 AM EDT MON SEP 23 2013
A LARGE AREA OF HIGH PRESSURE WILL ANCHORED ACROSS THE GREAT LAKES
FOR THE NEXT SEVERAL DAYS. WITH AN OVERALL LIGHT WIND REGIME...NO
HEADLINES ARE ANTICIPATED.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR MIZ016-017-022-
023-027>029-033>035-041.
FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MIZ008-015-018-
019-021-024>026-030>032-036-042.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JZ
SYNOPSIS...JZ
SHORT TERM...JK
LONG TERM...JZ
AVIATION...JZ
MARINE...JK
AREA FORECAST DISCUSSION
NWS GAYLORD MI
302 AM EDT MON SEP 23 2013
.SYNOPSIS...
ISSUED AT 249 AM EDT MON SEP 23 2013
HIGH PRESSURE WILL BRING AN EXTENDED PERIOD OF DRY WEATHER AND
MOSTLY CLEAR SKIES THROUGH THE WORK WEEK. HIGH TEMPERATURES WILL
SLOWLY MODERATE...WITH READINGS WELL ABOVE NORMAL WEDNESDAY THROUGH
SATURDAY. OVERNIGHT LOWS WILL BE COOL...AND FROST REMAINS A
POSSIBILITY IN MANY AREAS AGAIN TONIGHT.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 249 AM EDT MON SEP 23 2013
LARGE CANADIAN HIGH PRESSURE SLIDES INTO THE EASTERN LAKES THROUGH
TONIGHT WITH DEVELOPING WEAK RETURN FLOW ACROSS NORTHERN
MICHIGAN. SENSIBLE WEATHER CONCERNS IN THE SHORT TERM FOCUSED
PRIMARILY ON CLOUD TRENDS AND MIN TEMPERATURES TONIGHT.
TODAY...LOW LEVEL FLOW VEERS SOUTHEAST ON WESTERN PERIPHERY OF HIGH
PRESSURE WITH STRENGTHENING WARM AIR ADVECTION PUSHING H8
TEMPERATURES INTO THE +7C TO +9C RANGE. BRINGING THESE TEMPS DOWN
DRY ADIABATICALLY YIELDS HIGHS IN THE UPPER 50S TO MID 60S
/WARMEST WEST/. TRICKY CLOUD FORECAST WITH PLENTY OF RESIDUAL LOW
LEVEL MOISTURE ALONG THE LAKE HURON COAST/SAGINAW BAY TRAPPED
BENEATH SUBSIDENCE INVERSION WITH FAVORABLE DELTA T/S AND WEAK
ONSHORE FLOW. THE RUC 925-850MB RH FIELDS SHOW THESE LOWER CLOUDS
PLAGUING LAKE HURON COASTAL AREAS FROM ALPENA SOUTHWARD TOWARD SAGINAW
BAY THROUGH THE MORNING HOURS. AS DELTA T/S DECREASE WITH WARMING
ALOFT AND MUCH DRIER AIR WORKS INTO THE AREA /PWATS AROUND
0.4/...THE CLOUDS SHOULD /HOPEFULLY/ DISSIPATE. AS IS FREQUENTLY
THE CASE THIS TIME OF YEAR WITH REGARD TO LOW CLOUDS...WOULD NOT
BE SURPRISED IF THEY ENDED UP MORE PERSISTENT THAN CURRENTLY
FORECAST.
TONIGHT...ANOTHER POTENTIAL FROSTY NIGHT FOR PORTIONS OF THE AREA.
EXCELLENT RADIATIONAL COOLING SCENARIO ONCE AGAIN WITH CLEAR SKIES
AND LIGHT WINDS. SEE LITTLE REASON WHY LOW TEMPS WILL NOT DIP INTO
THE MIDDLE 30S OVER PORTIONS OF NORTHERN LOWER /ESPECIALLY EAST OF
I-75/...WITH SOME READINGS LIKELY INTO THE LOWER 30S IN THE
TYPICALLY COLDER LOCATIONS. WILL "BEEF UP" THE FROST WORDING IN
THE HWO...BUT WILL LEAVE HEADLINE DECISIONS TO THE DAY SHIFT BASED
ON LATEST OBS/MODEL TRENDS. AREAS OF FOG ALSO LIKELY...PARTICULARLY
IN THE COLDER VALLEY LOCATIONS AND AROUND INLAND LAKES.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 249 AM EDT MON SEP 23 2013
A SPECTACULAR WORK WEEK IS AHEAD (HARD TO IMAGINE A MULTI-DAY
STRETCH WITH QUIETER LONG-TERM FORECASTS THAN THE LAST FEW). THE ONE
INCOMING SYSTEM OF ANY NOTE IS A VIGOROUS SHORTWAVE IN THE 4-CORNERS
REGION EARLY THIS MORNING. THIS SYSTEM WILL EMERGE INTO THE CENTRAL
PLAINS TODAY...BUT THEN ENCOUNTER A BLOCKED PATTERN TO THE EAST...
WITH A STALLED UPPER LOW OVER NEW BRUNSWICK AND RIDGING IN THE
LAKES. THE INCOMING WAVE/S SOLUTION TO THIS PROBLEM IS CUT
UNDERNEATH THE RIDGE...MOVING THRU THE OHIO VALLEY ON WEDNESDAY.
THAT WILL BE TOO FAR SOUTH TO HAVE MUCH IMPACT ON US. THAT LEAVES
TEMPS AS THE ONLY CONCERN OF NOTE.
TUESDAY INTO WEDNESDAY...500MB RIDGING...WHICH IS OVERHEAD TO START
TUE MORNING...WILL DRIFT EAST TO LAKE HURON THRU TUE NIGHT. AS THE
UPPER LOW PASSES TO OUR SOUTH...THAT RIDGE WILL BE DISRUPTED...BUT
RIDGING WILL BEGIN TO FOLD OVER TOP OF THE LOW AND POKE IN FROM THE
SW ON WEDNESDAY. AT THE SURFACE...HIGH PRESSURE WILL BE A SEMI-
PERMANENT FEATURE IN THE VICINITY OF LAKE HURON. THIS PERSISTENT
RIDGING SURFACE AND ALOFT WILL MAINTAIN DEEP SUBSIDENCE AND ABUNDANT
DRY AIR. 850-700MB RH LEVELS ARE BELOW 20 PERCENT THROUGHOUT...AND
ARE BELOW 10 PERCENT MOST OF THE TIME.
THE UPPER LOW PASSING TO OUR SOUTH WILL LIKELY FEED SOME THIN CIRRUS
OVERHEAD TUE NIGHT/WED. OTHERWISE...SKIES WILL BE CLEAR. MAX TEMPS
WILL BE MAINLY IN THE MID TO UPPER 60S BOTH DAYS...WITH A FEW 70S
POSSIBLE WEDNESDAY. MIN TEMPS 40-45 FOR MOST...BUT THE INLAND COOL
SPOTS WILL LOWER INTO THE MID/UPPER 30S.
REST OF THE FORECAST...500MB RIDGING GETS PUMPED BACK INTO THE
REGION FROM THE SW FOR THE REST OF THE WORK WEEK. THU/FRI LOOK VERY
PLEASANT AND MILD...WITH MAX TEMPS MAINLY IN THE 70S.
THE GFS REMAINS A FAST OUTLIER WHEN IT COMES TO BREAKING DOWN THE
RIDGE...AND USHERING IN OUR NEXT CHANCE FOR PRECIP. THE ECMWF HAS
BEEN MUCH MORE CONSISTENT...AND IS PREFERRED. HEIGHTS WILL BE
STEADILY ERODED THIS WEEKEND...WITH THE ACTUAL TROF AXIS ARRIVING
MOST LIKELY ON SUNDAY. THIS SUPPORTS DRY WX INTO FRIDAY NIGHT...AND
CHANCE POPS SAT THRU SUNDAY. SATURDAY WILL REMAIN WARM...WITH
READING CLOSER TO CLIMO SUNDAY.
THOUGH IT LIES BEYOND THE SCOPE OF THIS FORECAST...DIFFICULT TO TELL
HOW LONG THE UNSETTLED WX WILL LAST. 12Z ECMWF WANTED TO LINGER THE
TROF IN THE REGION LONG ENOUGH TO REINFORCE IT WITH ARCTIC
ENERGY...CARVING OUT AN UNPLEASANT UPPER LOW OVER THE LAKES REGION
NEXT WEEK. WE SHALL SEE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1245 AM EDT MON SEP 23 2013
HIGH PRESSURE WILL DRIFT SLOWLY TOWARD THE EASTERN GREAT LAKES
THROUGH MONDAY NIGHT. PATCHY FOG POSSIBLE AT ALL TERMINALS
OVERNIGHT...ALTHOUGH NOT WIDESPREAD ENOUGH TO WARRANT A MENTION IN
THE TAFS. AREAS OF 3-4K STRATO-CU OFF OF LAKE HURON MAY IMPACT APN
THROUGH MONDAY MORNING...WITH MAINLY SKC ELSEWHERE. LIGHT WINDS
THROUGHOUT THE PERIOD.
&&
.MARINE...
ISSUED AT 249 AM EDT MON SEP 23 2013
A LARGE AREA OF HIGH PRESSURE WILL ANCHORED ACROSS THE GREAT LAKES
FOR THE NEXT SEVERAL DAYS. WITH AN OVERALL LIGHT WIND REGIME...NO
HEADLINES ARE ANTICIPATED.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...FREEZE WARNING UNTIL 8 AM EDT THIS MORNING FOR MIZ016-017-022-
023-027>029-033>035-041.
FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MIZ008-015-018-
019-021-024>026-030>032-036-042.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
SYNOPSIS...JZ
SHORT TERM...JK
LONG TERM...JZ
AVIATION...JK
MARINE...JK
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
646 PM CDT Tue Sep 24 2013
.SHORT TERM...(This Evening through Wednesday Night)
Issued at 231 PM CDT TUE SEP 24 2013
Relatively tranquil weather will prevail through much of the next 36
hours, with the one potential exception this afternoon.
As of early this afternoon, a surface low pressure center in the
process of occluding was analyzed near Kansas City, moving
east-southeastward. The shortwave trough aloft was nearly vertically
stacked, with the H85-H5 within 150 miles of the occluding surface
low. Visible satellite imagery has shown a gradual increase in
low-level cumulus, with clearing persistent ahead of the surface
low. A narrow corridor of weak instability has begun to develop
within a southeast to northwest arc. Short-term model guidance has
shown a forecast increase in 0-3km CAPE of up to 200-400J/Kg by
late afternoon over northeast portions of the EAX forecast area.
While the forecast instability is modest at best, this in
combination with strong vertical ascent may promote low-topped
convection to develop by mid to late afternoon. The RUC, NAM, GFS,
GEM, and HRRR outputs all suggest convection to develop in
northeastern sections of the CWA. With an environment characterized
by sufficient instability to maintain low-topped convection,
concomitant with moderate low-level (sfc-H85) directional wind shear
and moderate surface vorticity, the potential exists for a transient
funnel cloud or two underneath persistent updraft bases later this
afternoon in any mature convection that develops. The probability
for this to occur is relatively low, and any chance a vortex would
reach the surface is very low. Overall coverage of lightning
occurrence should be low as well due to the low-topped nature
anticipated with the convection. Much of this forecasted activity is
expected to wane shortly after sunset with the loss of diurnal
instability.
Otherwise, as the shortwave trough shifts east of the area tonight,
an upper ridge will build into the central CONUS on Wednesday. A
notable increase in high temperatures is expected tomorrow afternoon
with highs reaching the upper 70s to lower 80s under mostly clear
skies.
.LONG TERM...(Thursday through Tuesday)
Issued at 231 PM CDT TUE SEP 24 2013
For the later periods of the forecast, lovely late summer/early fall
conditions will dominate, though some thunderstorms might put a
damper on the beginning of the weekend. As Thursday dawns, an
amplified pattern will be in place across the nation, with a large
western CONUS trough juxtaposed against building eastern CONUS
ridge. This will leave our section of the country under rather
benign regime for Thursday and Friday. Models advertise 850mb
temperatures in the mid-teens late in the work week, leaving
expectations that highs will range in the 80s. These above
seasonally average temperatures late in the work week will be
occurring ahead of a frontal passage expected to occur Saturday.
Over the weekend the western CONUS trough will be filling and
lifting through the Plains States. The resulting frontal passage is
currently advertised to occur in our section of Kansas and Missouri
during the daylight hours of Saturday. Models are in decent
agreement on the evolution of the trough and timing of the
associated frontal passage, though given the jet streak noted diving
under the trough as it lifts out thoughts are that the eventual
timing will slow, leaving the frontal passage through our forecast
area lingering into the overnight hours of Saturday. Expectations
are that convection along the front will start Friday night across
areas from central Kansas into eastern Nebraska. These storms will
likely spread into eastern Kansas and far western Missouri towards
sunrise Saturday morning. Slow progress of the front might keep
storms percolating across western Missouri through much of the day,
while also slowly spreading east with the front. Have kept fairly
expansive likely POPs in place for Saturday night owing to low
confidence that the front will have completely cleared the forecast
area before nightfall.
Otherwise, beyond Saturday`s potential stormy weather, the remainder
of the weekend and into next work week (Sunday through Tuesday)
looks rather beautiful. Temperatures are currently expected to range
between highs in the 70s and lows in the 50s as a quasi-zonal upper
level pattern moves into the Plains in the wake of the exiting
trough.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening)
Issued at 637 PM CDT TUE SEP 24 2013
Expect ceilings to remain in the low end VFR range although we should
see them bounce between scattered and broken through the evening
hours. Plenty of moisture will remain trapped within the boundary
layer and as clouds thin out during the pre-dawn hours believe MVFR
fog will form at KMCI and KSTJ as air temperatures drop close to the
dewpoints. UPS fog output also supports at least MVFR fog and
possibly IFR visibilities. Confidence is not high enough to support
that as there is a chance broken cloud cover could linger through the
night and inhibit IFR fog from forming.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...Blair
LONG TERM...Cutter
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
641 PM EDT MON SEP 23 2013
.SYNOPSIS...
LARGE AREA OF CANADIAN HIGH PRESSURE CENTERED OVER THE GREAT LAKES
WILL REMAIN NEARLY STATIONARY THROUGH LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
A SURFACE RIDGE CONTINUES TO BUILD IN. THE BIG QUESTION IS HOW
COLD WILL IT GET AND HOW MUCH FROST WILL FORM. AT THIS TIME THE
CLOUDS ARE DEFINITELY ON THE DECREASE. THE HRRR AND MOST OF THE
MODELS INDICATE THAT MOST AREAS WILL BECOME MOSTLY
CLEAR...HOWEVER...SOME CLOUDS WILL LINGER OR REDEVELOP OVER THE
EXTREME NORTHWEST. THE MAIN AREA OF CONCERN FOR FROST IS IN THE
EAST. HAVE MADE NO CHANGES TO THE FROST ADVISORY OVER INLAND
AREAS OF NW PA AND EXTREME NE OH. OVER THE CENTRAL HIGHLANDS WILL
CONTINUE WITH PATCHY FROST. USED A BLEND OF GUIDANCE FOR THE
LOWS. WILL WATCH TO SEE WHETHER FROST NEEDS TO BE ADDED TO MORE
AREAS AND WHETHER THE ADVISORY NEEDS TO BE EXPANDED.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/...
THE RIDGE WILL BE NORTH TO SOUTH ACROSS THE AREA THROUGH THURSDAY
AND THEN IT WILL SLOWLY SHIFT TO THE EAST. ON TUESDAY MOSTLY SUNNY
SKIES EXCEPT NEAR TOLEDO. AN UPPER LOW WILL MOVE ACROSS THE OHIO
VALLEY TUESDAY NIGHT INTO WEDNESDAY EVENING. THE MAIN AFFECT FROM
THIS SYSTEM WILL BE SOME CIRRUS. WILL GO FOR PARTLY CLOUDY.
OTHERWISE MOSTLY CLEAR OR MOSTLY SUNNY. USED A BLEND OF GUIDANCE
FOR THE TEMPERATURE FORECAST.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGH AMPLITUDE RIDGE ALOFT BUILDS OVER THE GREAT LAKES ON FRIDAY.
SURFACE HIGH PRESSURE WILL BE OVER THE EASTERN GREAT LAKES WITH AN
EASTERLY LOW LEVEL FLOW. EXPECTING TEMPERATURES TO CLIMB ABOVE
NORMAL INTO THE MID 70S MOST AREAS WITH FULL SUN. THE FLOW BACKS
AROUND TO MORE SOUTHERLY ON SATURDAY AS THE SURFACE HIGH SHIFTS
TOWARDS THE EAST COAST WITH ABOVE NORMAL TEMPERATURES MAKING A RUN
AT 80 DEGREES IN THE WEST.
THE NEXT TROUGH WILL LIFT OUT OF THE PLAINS TOWARDS THE AREA ON
SUNDAY. THE GFS WHICH HAS OFFERED A FASTER AND MORE PROGRESSIVE
SOLUTION IS SHOWING SIGNS OF SLOWING DOWN WITH A DEEPER
TROUGH...MORE IN LINE WITH THE ECMWF AND GEM. REMOVED THE LOW POP
FROM SATURDAY NIGHT IN THE EASTERN COUNTIES WITH A CHANCE OF SHOWERS
STILL IN THE FORECAST FOR SUNDAY AND SUNDAY NIGHT. POPS MAY NEED TO
BE SLOWED DOWN FURTHER GIVEN THE DEPTH OF THE WESTERN TROUGH WITH
SOME POTENTIAL FOR THE UPPER LOW TO CLOSE OFF OVER THE FOUR CORNERS
REGION.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
STRATOCU DECK HOLDING FIRM ACROSS THE AREA WITH CLOUDS SLOWLY
SCATTERING OUT TO OUR NORTHEAST. A SIZABLE GAP IS ALSO IN PLACE
ACROSS WESTERN LAKE ERIE. CEILINGS ARE ACTUALLY LOWERING IN SOME
AREAS AS SUBSIDENCE INCREASES WITH A STRENGTHENING SURFACE HIGH TO
OUR NORTH. EXPECTING CLOUD HEIGHTS IN THE 2500-4000 FOOT RANGE TO
PERSIST FOR MOST OF THE AFTERNOON WITH CLOUDS SLOWLY ERODING
AROUND THE FRINGES. SKIES ARE EXPECTED TO BE MOSTLY CLEAR BY
00-02Z ALTHOUGH SOME UNCERTAINTY EXISTS IN TIMING AT EACH SITE.
VFR CONDITIONS THEN EXPECTED FOR THE DURATION OF THE TAF CYCLE
EXCEPT AT TOL WHERE A STRATOCU DECK MAY ONCE AGAIN DEVELOP OFF OF
LAKE ERIE LATE TONIGHT. A LIGHT NORTHEAST FLOW THIS AFTERNOON WILL
BECOME NEARLY CALM OVERNIGHT.
OUTLOOK...VFR.
&&
.MARINE...
GOOD MARINE CONDITIONS EXPECTED THIS WEEK WITH HIGH PRESSURE
REMAINING NEARLY STATIONARY OVER THE EASTERN GREAT LAKES. A LIGHT
NORTHEASTERLY FLOW WILL INCREASE SLIGHTLY ON WEDNESDAY AS A WEAK
SYSTEM MOVES THROUGH THE LOWER OHIO VALLEY. THE HIGH WILL STRENGTHEN
AGAIN FOR THE END OF THE WEEK BEFORE SHIFTING TOWARDS THE EAST
COAST. WINDS WILL GENERALLY BE 10 KNOTS OR LESS WITH WAVES OF 2 FEET
OR LESS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...FROST ADVISORY FROM 3 AM TO 9 AM EDT TUESDAY FOR OHZ013-014-
022-023-033.
PA...FROST ADVISORY FROM 3 AM TO 9 AM EDT TUESDAY FOR PAZ002-003.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA/OUDEMAN
SHORT TERM...KIELTYKA
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
346 PM EDT MON SEP 23 2013
.SYNOPSIS...
LARGE AREA OF CANADIAN HIGH PRESSURE CENTERED OVER THE GREAT LAKES
WILL REMAIN NEARLY STATIONARY THROUGH LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
A SURFACE RIDGE CONTINUES TO BUILD IN. THE BIG QUESTION IS WHEN WILL
IT CLEAR AND THEN HOW COLD WILL IT GET AND HOW MUCH FROST WILL
FORM. AT THIS TIME THE TREND AND MODELS AGREE THAT THE CLOUDS WILL
DECREASE FROM THE NORTHEAST. THE HRRR AND MOST OF THE MODELS
INDICATE THAT MOST AREAS WILL BECOME MOSTLY CLEAR...HOWEVER...SOME
CLOUDS WILL LINGER OR REDEVELOP OVER THE EXTREME NORTHWEST. THE MAIN
AREA OF CONCERN FOR FROST IS IN THE EAST. WILL GO WITH AN ADVISORY
OVER INLAND AREAS OF NW PA AND EXTREME NE OH. OVER THE CENTRAL
HIGHLANDS WILL GO WITH PATCHY FROST. USED A BLEND OF GUIDANCE FOR
THE LOWS. THE NEXT SHIFT WILL HAVE TO WATCH WHETHER FROST NEEDS TO
BE ADDED TO MORE AREAS AND WHETHER THE ADVISORY NEEDS TO BE
EXPANDED.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/...
THE RIDGE WILL BE NORTH TO SOUTH ACROSS THE AREA THROUGH THURSDAY
AND THEN IT WILL SLOWLY SHIFT TO THE EAST. ON TUESDAY MOSTLY SUNNY
SKIES EXCEPT NEAR TOLEDO. AN UPPER LOW WILL MOVE ACROSS THE OHIO
VALLEY TUESDAY NIGHT INTO WEDNESDAY EVENING. THE MAIN AFFECT FROM
THIS SYSTEM WILL BE SOME CIRRUS. WILL GO FOR PARTLY CLOUDY.
OTHERWISE MOSTLY CLEAR OR MOSTLY SUNNY. USED A BLEND OF GUIDANCE
FOR THE TEMPERATURE FORECAST.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGH AMPLITUDE RIDGE ALOFT BUILDS OVER THE GREAT LAKES ON FRIDAY.
SURFACE HIGH PRESSURE WILL BE OVER THE EASTERN GREAT LAKES WITH AN
EASTERLY LOW LEVEL FLOW. EXPECTING TEMPERATURES TO CLIMB ABOVE
NORMAL INTO THE MID 70S MOST AREAS WITH FULL SUN. THE FLOW BACKS
AROUND TO MORE SOUTHERLY ON SATURDAY AS THE SURFACE HIGH SHIFTS
TOWARDS THE EAST COAST WITH ABOVE NORMAL TEMPERATURES MAKING A RUN
AT 80 DEGREES IN THE WEST.
THE NEXT TROUGH WILL LIFT OUT OF THE PLAINS TOWARDS THE AREA ON
SUNDAY. THE GFS WHICH HAS OFFERED A FASTER AND MORE PROGRESSIVE
SOLUTION IS SHOWING SIGNS OF SLOWING DOWN WITH A DEEPER
TROUGH...MORE IN LINE WITH THE ECMWF AND GEM. REMOVED THE LOW POP
FROM SATURDAY NIGHT IN THE EASTERN COUNTIES WITH A CHANCE OF SHOWERS
STILL IN THE FORECAST FOR SUNDAY AND SUNDAY NIGHT. POPS MAY NEED TO
BE SLOWED DOWN FURTHER GIVEN THE DEPTH OF THE WESTERN TROUGH WITH
SOME POTENTIAL FOR THE UPPER LOW TO CLOSE OFF OVER THE FOUR CORNERS
REGION.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
STRATOCU DECK HOLDING FIRM ACROSS THE AREA WITH CLOUDS SLOWLY
SCATTERING OUT TO OUR NORTHEAST. A SIZABLE GAP IS ALSO IN PLACE
ACROSS WESTERN LAKE ERIE. CEILINGS ARE ACTUALLY LOWERING IN SOME
AREAS AS SUBSIDENCE INCREASES WITH A STRENGTHENING SURFACE HIGH TO
OUR NORTH. EXPECTING CLOUD HEIGHTS IN THE 2500-4000 FOOT RANGE TO
PERSIST FOR MOST OF THE AFTERNOON WITH CLOUDS SLOWLY ERODING
AROUND THE FRINGES. SKIES ARE EXPECTED TO BE MOSTLY CLEAR BY
00-02Z ALTHOUGH SOME UNCERTAINTY EXISTS IN TIMING AT EACH SITE.
VFR CONDITIONS THEN EXPECTED FOR THE DURATION OF THE TAF CYCLE
EXCEPT AT TOL WHERE A STRATOCU DECK MAY ONCE AGAIN DEVELOP OFF OF
LAKE ERIE LATE TONIGHT. A LIGHT NORTHEAST FLOW THIS AFTERNOON WILL
BECOME NEARLY CALM OVERNIGHT.
OUTLOOK...VFR.
&&
.MARINE...
GOOD MARINE CONDITIONS EXPECTED THIS WEEK WITH HIGH PRESSURE
REMAINING NEARLY STATIONARY OVER THE EASTERN GREAT LAKES. A LIGHT
NORTHEASTERLY FLOW WILL INCREASE SLIGHTLY ON WEDNESDAY AS A WEAK
SYSTEM MOVES THROUGH THE LOWER OHIO VALLEY. THE HIGH WILL STRENGTHEN
AGAIN FOR THE END OF THE WEEK BEFORE SHIFTING TOWARDS THE EAST
COAST. WINDS WILL GENERALLY BE 10 KNOTS OR LESS WITH WAVES OF 2 FEET
OR LESS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...FROST ADVISORY FROM 3 AM TO 9 AM EDT TUESDAY FOR OHZ013-014-
022-023-033.
PA...FROST ADVISORY FROM 3 AM TO 9 AM EDT TUESDAY FOR PAZ002-003.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
143 AM EDT MON SEP 23 2013
.SYNOPSIS...
COOL CANADIAN HIGH PRESSURE WILL BUILD EAST ACROSS THE GREAT LAKES
THROUGH MONDAY. THIS HIGH WILL REMAIN IN THE GREAT LAKES VICINITY
THROUGH MOST OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE GREAT LAKES REGION REMAINS BETWEEN AN UPPER LEVEL TROUGH OVER
QUEBEC AND A RIDGE BUILDING OVER THE UPPER MIDWEST. ENOUGH
TROUGHINESS REMAINS ALONG WITH THE 850MB COLD POOL(TEMPS DOWN TO -2C
OVER ONTARIO) TO MAINTAIN CONSIDERABLE CLOUD COVER DOWNWIND OF THE
LAKE. AS NOTED EARLY...NAM SOUNDINGS ARE ALREADY RUNNING A LITTLE
TOO OPTIMISTIC WITH CLEARING WHILE RUC SOUNDINGS KEEP EASTERN
AREAS CLOUDY ALL NIGHT BENEATH THE LOWERING INVERSION. HRRR IS
SIMILAR...HINTING AT SOME BREAKS BUT NOT COMPLETELY CLEARING.
WILL CARRY A MOSTLY CLEAR FORECAST TOWARDS FINDLAY WITH MOSTLY
CLOUDY SKIES FOR MOST OF THE NIGHT ACROSS THE EASTERN HALF OF THE
AREA. HAVE ADJUSTED THE HOURLY SKY GRIDS...MERGING THE FORECAST
WITH THE LATEST GUIDANCE. MOS GUIDANCE ALSO TOO QUICK WITH THE
CLEARING TREND SO WILL GO 2-5 DEGREES WARMER TONIGHT FOR AREAS
EAST OF A CLE-CAK LINE. THIS STILL SEEMS TO BE REASONABLE. ONLY
MADE ADJUSTMENTS TO SOME HOURLY TEMPERATURES. TEMPERATURES WILL
FALL QUICKLY WITH ANY SIZABLE BREAKS IN THE CLOUDS. MAY STILL HAVE
A SPRINKLE OR TWO FOR A LITTLE WHILE THIS EVENING FROM THE STRATUS
DECK.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
A DRY STRETCH OF WEATHER WITH COOL NIGHTS TO FOLLOW DURING THE SHORT
TERM. HIGH PRESSURE WILL REMAIN OVER THE EASTERN GREAT LAKES THROUGH
TUESDAY...SHIFTING SLIGHTLY TO THE NORTH ON WEDNESDAY. DIURNAL CU
EXPECTED ONCE AGAIN ON MONDAY BEFORE WE FINALLY MIX OUT OUR MOISTURE
AND CLEAR FOR MONDAY NIGHT. THIS WILL SET UP FOR A CHILLY NIGHT ON
MONDAY WITH MOST INLAND AREAS DIPPING TO NEAR 40 DEGREES. SOME OF
THE COOLER SPOTS IN NE OHIO WILL DIP INTO THE UPPER 30S WITH MID 30S
FOR INTERIOR NW PA. HAVE INCLUDED AREAS OF FROST FOR THOSE COOLEST
SPOTS AND THERE IS POTENTIAL THAT WE MAY NEED A FROST ADVISORY FOR
ERIE AND CRAWFORD PA. A HEALTHY DIURNAL SPREAD WILL ALLOW HIGHS TO
RECOVER INTO THE LOW AND MID 60S FOR TUESDAY...THEN COOL BACK INTO
THE 40S FOR TUESDAY NIGHT. LEANED THE FORECAST TOWARDS THE RAW MODEL
TEMPERATURES WHICH ARE SLIGHTLY COOLER THAN MOS GUIDANCE THROUGH THE
SHORT TERM.
UPPER LEVEL LOW OVER THE GREAT BASIN WILL MOVE NORTHEAST ACROSS THE
PLAINS ON MONDAY AND ENCOUNTER SOME RESISTANCE BY THE HIGH AMPLITUDE
UPPER LEVEL RIDGE OVER THE GREAT LAKES REGION. THE UPPER LOW WILL
WEAKEN AS IT SLIDES EAST ACROSS THE OHIO VALLEY ON TUESDAY NIGHT AND
WEDNESDAY. MODELS KEEP THE QPF SOUTH OF THE FORECAST AREA AND GIVEN
THE RESIDENT DRY AIR MASS IN PLACE...WILL KEEP THE FORECAST DRY WITH
JUST SOME INCREASE IN CLOUDS ON WEDNESDAY. TEMPS WILL RETURN TO NEAR
70 MOST AREAS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
A RIDGE OF HIGH PRESSURE WILL BE OVER THE AREA TO START THE FORECAST
PERIOD AND THEN IT WILL SHIFT SLOWLY EAST AS A WEAKENING COLD FRONT
ADVANCES TOWARDS THE REGION. SOME QUESTION AS TO THE TIMING OF THE
FRONT FOR LATE IN THE WEEKEND. THE 12Z GFS IS MUCH QUICKER THAN THE
ECMWF AND THE CANADIAN MODEL. AT THIS TIME LEANING MORE TOWARD THE
SLOWER MODELS. SO THE MAIN CHANCE OF PRECIPITATION WILL BE ON SUNDAY
INTO SUNDAY NIGHT. IT SEEMS STABLE SO ONLY FORECASTING SHOWERS. USED
A BLEND OF GUIDANCE FOR THE NEAR NORMAL TEMPERATURES.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
THERE WILL BE A FEW PATCHES OF MVFR CEILINGS THIS MORNING AS LOW
LEVEL MOISTURE REMAINS TRAPPED BELOW THE SUBSIDENCE INVERSION. IT
WILL TAKE A WHILE TO MIX AWAY THE 035-045BKN/OVC STRATOCUMULUS
OVER THE EASTERN GREAT LAKES. THE CEILINGS WILL EXPAND INTO KTOL
AND KFDY THIS MORNING. CEILINGS WILL SCATTER OUT BY MID TO LATE
AFTERNOON... THEN CLEAR SKIES TONIGHT WITH THE FLOW VEERING FROM
NE TO LIGHT EASTERLY.
OUTLOOK...VFR.
&&
.MARINE...
A RIDGE OF HIGH PRESSURE WILL BE BUILDING IN TONIGHT. WILL LET THE
SMALL CRAFT ADVISORY AND RIP CURRENT RISK EXPIRE/CANCEL AS THE WINDS
AND WAVES ARE DECREASING. HOWEVER AS THE RIDGE IS BUILDING IN
TONIGHT THE NORTHEAST FLOW GRADIENT WILL INCREASE AND THAT COULD
CAUSE THE WAVES TO GET CLOSE TO SMALL CRAFT ADVISORY CRITERIA AND
AGAIN ON MONDAY. HOWEVER...AT THIS TIME IT SEEMS THAT 2 TO 4 FOOT
WAVES SHOULD HANDLE IT. AS THE RIDGE BECOMES STRONGER MONDAY NIGHT
AND TUESDAY THE WINDS WILL BE LIGHTER...THUS DECREASING THE WAVES.
THE RIDGE WILL BE AROUND THE LAKE THROUGH FRIDAY AND THAT WILL MEAN
AN EAST OR NORTHEAST FLOW. AT THIS TIME A SMALL CRAFT ADVISORY IS
NOT EXPECTED AS THE NORTHEAST FLOW SHOULD NOT BE STRONG ENOUGH TO
CAUSE 3 TO 5 FOOT WAVES BUT THIS WILL HAVE TO BE WATCHED AS
NORTHEAST FLOWS ARE NOTORIOUS FOR CAUSING HIGH WAVES ESPECIALLY ON
THE WEST END OF THE LAKE BECAUSE OF THE LONG FETCH.
A COLD FRONT WILL BE APPROACHING THE LAKE FOR LATE IN THE UPCOMING
WEEKEND SHIFTING THE WINDS TO SOUTHERLY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KEC
NEAR TERM...KEC/OUDEMAN
SHORT TERM...KEC
LONG TERM...KIELTYKA
AVIATION...KOSARIK
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS NORMAN OK
1203 PM CDT MON SEP 23 2013
.UPDATE...
ONLY CHANGE TO GOING FORECAST PACKAGE WAS TO INCREASE WIND SPEEDS
THROUGH THE AFTERNOON AHEAD OF WEAK FRONTAL BOUNDARY. SOUTHERLY
WINDS GUSTING 30 TO 40 MPH WILL REMAIN POSSIBLE ACROSS MAINLY
NORTHWEST OKLAHOMA THROUGH ABOUT 3 OR 4 PM.
&&
.PREV DISCUSSION... /ISSUED 637 AM CDT MON SEP 23 2013/
UPDATE...
REMOVED POPS ACROSS NORTHWESTERN OKLAHOMA THIS MORNING.
DISCUSSION...
ANY SHOWER/ISOLATED THUNDER ACTIVITY ACROSS THE PANHANDLES HAS
LIFTED NORTH/NORTHEAST INTO FAR SOUTHWESTERN KANSAS. DO NOT EXPECT
ANY SHOWERS TO IMPACT FAR NORTHWESTERN OKLAHOMA THIS MORNING.
JTK
PREV DISCUSSION... /ISSUED 554 AM CDT MON SEP 23 2013/
AVIATION...
VFR CONDITIONS ARE EXPECTED. GUSTY SOUTH WIND IN WESTERN OKLAHOMA
WILL GIVE WAY TO LIGHT NORTH WINDS BEHIND A WEAK FRONT OVERNIGHT.
PREV DISCUSSION... /ISSUED 507 AM CDT MON SEP 23 2013/
UPDATE...
UPDATED POPS FOR THIS MORNING...
DISCUSSION...
REMOVED POPS FROM 11Z TO 12Z PER RADAR ANALYSIS OF ONGOING
SHOWERS ACROSS CENTRAL TX/OK PANHANDLES BEST FOCUS FOR DEVELOPMENT
THIS MORNING REMAINS JUST EAST OF THE WEAK SFC FRONT...WHICH
CURRENTLY EXTENDS FROM WRN KS THROUGH ERN NM. WV SAT SHOWS THE
PRIMARY UPPER LOW LIFTING N/NE OFF THE NRN CO FRONT RANGE...WITH
BETTER FOCUS FOR PRECIP ACROSS ERN CO/WRN KS INTO SWRN NE. WITH
THE CURRENT TRACK OF THE SFC LOW ACROSS E. CENTRAL CO AND THE
PARENT 500MB LOW...WOULD NOT BE SURPRISED IF SHOWERS THIS MORNING
JUST SKIRT FAR NWRN OK...OR MISS COMPLETELY. 07Z RUN OF THE HRRR
SUPPORTS THE LATTER SOLUTION...WITH SHOWERS LIFTING NORTH ACROSS
THE OK PANHANDLE INTO SWRN KS MISSING NWRN OK COMPLETELY.
HOWEVER... THIS SOLUTION HAS THE SRN TERMINUS OF CONVECTION
FARTHER NORTH THAN CURRENTLY OBSERVED. WILL CONTINUE TO RUN WITH
SLIGHT CHANCE POPS ACROSS FAR NWRN OK THROUGH 14Z...AS ENSEMBLE
RUNS OF THE HRRR AND SOLUTIONS FROM THE NSSL AND OUN WRF CLIP FAR
NWRN OK WITH A SHOWER OR TWO THROUGH 14Z.
JTK
PREV DISCUSSION... /ISSUED 355 AM CDT MON SEP 23 2013/
DISCUSSION...
AN UPPER TROUGH MOVING QUICKLY INTO THE CENTRAL PLAINS FROM THE
WEST WILL PASS ACROSS NORTHERN OKLAHOMA TODAY. MODELS, RADAR, AND
SATELLITE TRENDS EACH SUGGEST THAT NEARLY ALL RAIN WILL PASS NORTH
OF OKLAHOMA. THE MAIN EFFECT WILL BE MID-LEVEL CLOUDS. A WEAK
SURFACE FRONT WILL CHANGE WINDS TO THE NORTH. A TREND TOWARDS HOT
WEATHER STARTS TUESDAY AND LASTS INTO FRIDAY BEFORE A STRONGER
UPPER LEVEL SYSTEM BRINGS STRONGER LIFT ACROSS OKLAHOMA AND A
FRONT MOVES INTO THE STATE. THE MORE HUMID BOUNDARY LAYER THAT
WILL EXIST SHOULD HAVE NO PROBLEM PRODUCING RAIN AND THUNDERSTORMS
LATE FRIDAY AND SATURDAY. COOLER AND DRIER AIR WILL FOLLOW SUNDAY.
09
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 81 58 83 57 / 0 0 0 0
HOBART OK 83 57 85 57 / 0 0 0 0
WICHITA FALLS TX 85 59 88 59 / 0 0 0 0
GAGE OK 84 52 82 55 / 10 0 0 0
PONCA CITY OK 80 57 81 55 / 10 10 0 0
DURANT OK 84 59 88 59 / 0 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
03/11
AREA FORECAST DISCUSSION
NWS NORMAN OK
637 AM CDT MON SEP 23 2013
.UPDATE...
REMOVED POPS ACROSS NORTHWESTERN OKLAHOMA THIS MORNING.
&&
.DISCUSSION...
ANY SHOWER/ISOLATED THUNDER ACTIVITY ACROSS THE PANHANDLES HAS
LIFTED NORTH/NORTHEAST INTO FAR SOUTHWESTERN KANSAS. DO NOT EXPECT
ANY SHOWERS TO IMPACT FAR NORTHWESTERN OKLAHOMA THIS MORNING.
JTK
&&
.PREV DISCUSSION... /ISSUED 554 AM CDT MON SEP 23 2013/
AVIATION...
VFR CONDITIONS ARE EXPECTED. GUSTY SOUTH WIND IN WESTERN OKLAHOMA
WILL GIVE WAY TO LIGHT NORTH WINDS BEHIND A WEAK FRONT OVERNIGHT.
PREV DISCUSSION... /ISSUED 507 AM CDT MON SEP 23 2013/
UPDATE...
UPDATED POPS FOR THIS MORNING...
DISCUSSION...
REMOVED POPS FROM 11Z TO 12Z PER RADAR ANALYSIS OF ONGOING
SHOWERS ACROSS CENTRAL TX/OK PANHANDLES BEST FOCUS FOR DEVELOPMENT
THIS MORNING REMAINS JUST EAST OF THE WEAK SFC FRONT...WHICH
CURRENTLY EXTENDS FROM WRN KS THROUGH ERN NM. WV SAT SHOWS THE
PRIMARY UPPER LOW LIFTING N/NE OFF THE NRN CO FRONT RANGE...WITH
BETTER FOCUS FOR PRECIP ACROSS ERN CO/WRN KS INTO SWRN NE. WITH
THE CURRENT TRACK OF THE SFC LOW ACROSS E. CENTRAL CO AND THE
PARENT 500MB LOW...WOULD NOT BE SURPRISED IF SHOWERS THIS MORNING
JUST SKIRT FAR NWRN OK...OR MISS COMPLETELY. 07Z RUN OF THE HRRR
SUPPORTS THE LATTER SOLUTION...WITH SHOWERS LIFTING NORTH ACROSS
THE OK PANHANDLE INTO SWRN KS MISSING NWRN OK COMPLETELY.
HOWEVER... THIS SOLUTION HAS THE SRN TERMINUS OF CONVECTION
FARTHER NORTH THAN CURRENTLY OBSERVED. WILL CONTINUE TO RUN WITH
SLIGHT CHANCE POPS ACROSS FAR NWRN OK THROUGH 14Z...AS ENSEMBLE
RUNS OF THE HRRR AND SOLUTIONS FROM THE NSSL AND OUN WRF CLIP FAR
NWRN OK WITH A SHOWER OR TWO THROUGH 14Z.
JTK
PREV DISCUSSION... /ISSUED 355 AM CDT MON SEP 23 2013/
DISCUSSION...
AN UPPER TROUGH MOVING QUICKLY INTO THE CENTRAL PLAINS FROM THE
WEST WILL PASS ACROSS NORTHERN OKLAHOMA TODAY. MODELS, RADAR, AND
SATELLITE TRENDS EACH SUGGEST THAT NEARLY ALL RAIN WILL PASS NORTH
OF OKLAHOMA. THE MAIN EFFECT WILL BE MID-LEVEL CLOUDS. A WEAK
SURFACE FRONT WILL CHANGE WINDS TO THE NORTH. A TREND TOWARDS HOT
WEATHER STARTS TUESDAY AND LASTS INTO FRIDAY BEFORE A STRONGER
UPPER LEVEL SYSTEM BRINGS STRONGER LIFT ACROSS OKLAHOMA AND A
FRONT MOVES INTO THE STATE. THE MORE HUMID BOUNDARY LAYER THAT
WILL EXIST SHOULD HAVE NO PROBLEM PRODUCING RAIN AND THUNDERSTORMS
LATE FRIDAY AND SATURDAY. COOLER AND DRIER AIR WILL FOLLOW SUNDAY.
09
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 81 58 83 57 / 0 0 0 0
HOBART OK 83 57 85 57 / 0 0 0 0
WICHITA FALLS TX 85 59 88 59 / 0 0 0 0
GAGE OK 84 52 82 55 / 10 0 0 0
PONCA CITY OK 80 57 81 55 / 10 10 0 0
DURANT OK 84 59 88 59 / 0 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
04/09/09
AREA FORECAST DISCUSSION
NWS NORMAN OK
554 AM CDT MON SEP 23 2013
.AVIATION...
VFR CONDITIONS ARE EXPECTED. GUSTY SOUTH WIND IN WESTERN OKLAHOMA
WILL GIVE WAY TO LIGHT NORTH WINDS BEHIND A WEAK FRONT OVERNIGHT.
&&
.PREV DISCUSSION... /ISSUED 507 AM CDT MON SEP 23 2013/
UPDATE...
UPDATED POPS FOR THIS MORNING...
DISCUSSION...
REMOVED POPS FROM 11Z TO 12Z PER RADAR ANALYSIS OF ONGOING
SHOWERS ACROSS CENTRAL TX/OK PANHANDLES BEST FOCUS FOR DEVELOPMENT
THIS MORNING REMAINS JUST EAST OF THE WEAK SFC FRONT...WHICH
CURRENTLY EXTENDS FROM WRN KS THROUGH ERN NM. WV SAT SHOWS THE
PRIMARY UPPER LOW LIFTING N/NE OFF THE NRN CO FRONT RANGE...WITH
BETTER FOCUS FOR PRECIP ACROSS ERN CO/WRN KS INTO SWRN NE. WITH
THE CURRENT TRACK OF THE SFC LOW ACROSS E. CENTRAL CO AND THE
PARENT 500MB LOW...WOULD NOT BE SURPRISED IF SHOWERS THIS MORNING
JUST SKIRT FAR NWRN OK...OR MISS COMPLETELY. 07Z RUN OF THE HRRR
SUPPORTS THE LATTER SOLUTION...WITH SHOWERS LIFTING NORTH ACROSS
THE OK PANHANDLE INTO SWRN KS MISSING NWRN OK COMPLETELY.
HOWEVER... THIS SOLUTION HAS THE SRN TERMINUS OF CONVECTION
FARTHER NORTH THAN CURRENTLY OBSERVED. WILL CONTINUE TO RUN WITH
SLIGHT CHANCE POPS ACROSS FAR NWRN OK THROUGH 14Z...AS ENSEMBLE
RUNS OF THE HRRR AND SOLUTIONS FROM THE NSSL AND OUN WRF CLIP FAR
NWRN OK WITH A SHOWER OR TWO THROUGH 14Z.
JTK
PREV DISCUSSION... /ISSUED 355 AM CDT MON SEP 23 2013/
DISCUSSION...
AN UPPER TROUGH MOVING QUICKLY INTO THE CENTRAL PLAINS FROM THE
WEST WILL PASS ACROSS NORTHERN OKLAHOMA TODAY. MODELS, RADAR, AND
SATELLITE TRENDS EACH SUGGEST THAT NEARLY ALL RAIN WILL PASS NORTH
OF OKLAHOMA. THE MAIN EFFECT WILL BE MID-LEVEL CLOUDS. A WEAK
SURFACE FRONT WILL CHANGE WINDS TO THE NORTH. A TREND TOWARDS HOT
WEATHER STARTS TUESDAY AND LASTS INTO FRIDAY BEFORE A STRONGER
UPPER LEVEL SYSTEM BRINGS STRONGER LIFT ACROSS OKLAHOMA AND A
FRONT MOVES INTO THE STATE. THE MORE HUMID BOUNDARY LAYER THAT
WILL EXIST SHOULD HAVE NO PROBLEM PRODUCING RAIN AND THUNDERSTORMS
LATE FRIDAY AND SATURDAY. COOLER AND DRIER AIR WILL FOLLOW SUNDAY.
09
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 81 58 83 57 / 0 0 0 0
HOBART OK 83 57 85 57 / 0 0 0 0
WICHITA FALLS TX 85 59 88 59 / 0 0 0 0
GAGE OK 84 52 82 55 / 20 0 0 0
PONCA CITY OK 80 57 81 55 / 10 10 0 0
DURANT OK 84 59 88 59 / 0 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
04/09/09
AREA FORECAST DISCUSSION
NWS NORMAN OK
507 AM CDT MON SEP 23 2013
.UPDATE...
UPDATED POPS FOR THIS MORNING...
&&
.DISCUSSION...
REMOVED POPS FROM 11Z TO 12Z PER RADAR ANALYSIS OF ONGOING
SHOWERS ACROSS CENTRAL TX/OK PANHANDLES BEST FOCUS FOR DEVELOPMENT
THIS MORNING REMAINS JUST EAST OF THE WEAK SFC FRONT...WHICH
CURRENTLY EXTENDS FROM WRN KS THROUGH ERN NM. WV SAT SHOWS THE
PRIMARY UPPER LOW LIFTING N/NE OFF THE NRN CO FRONT RANGE...WITH
BETTER FOCUS FOR PRECIP ACROSS ERN CO/WRN KS INTO SWRN NE. WITH
THE CURRENT TRACK OF THE SFC LOW ACROSS E. CENTRAL CO AND THE
PARENT 500MB LOW...WOULD NOT BE SURPRISED IF SHOWERS THIS MORNING
JUST SKIRT FAR NWRN OK...OR MISS COMPLETELY. 07Z RUN OF THE HRRR
SUPPORTS THE LATTER SOLUTION...WITH SHOWERS LIFTING NORTH ACROSS
THE OK PANHANDLE INTO SWRN KS MISSING NWRN OK COMPLETELY.
HOWEVER... THIS SOLUTION HAS THE SRN TERMINUS OF CONVECTION
FARTHER NORTH THAN CURRENTLY OBSERVED. WILL CONTINUE TO RUN WITH
SLIGHT CHANCE POPS ACROSS FAR NWRN OK THROUGH 14Z...AS ENSEMBLE
RUNS OF THE HRRR AND SOLUTIONS FROM THE NSSL AND OUN WRF CLIP FAR
NWRN OK WITH A SHOWER OR TWO THROUGH 14Z.
JTK
&&
.PREV DISCUSSION... /ISSUED 355 AM CDT MON SEP 23 2013/
DISCUSSION...
AN UPPER TROUGH MOVING QUICKLY INTO THE CENTRAL PLAINS FROM THE
WEST WILL PASS ACROSS NORTHERN OKLAHOMA TODAY. MODELS, RADAR, AND
SATELLITE TRENDS EACH SUGGEST THAT NEARLY ALL RAIN WILL PASS NORTH
OF OKLAHOMA. THE MAIN EFFECT WILL BE MID-LEVEL CLOUDS. A WEAK
SURFACE FRONT WILL CHANGE WINDS TO THE NORTH. A TREND TOWARDS HOT
WEATHER STARTS TUESDAY AND LASTS INTO FRIDAY BEFORE A STRONGER
UPPER LEVEL SYSTEM BRINGS STRONGER LIFT ACROSS OKLAHOMA AND A
FRONT MOVES INTO THE STATE. THE MORE HUMID BOUNDARY LAYER THAT
WILL EXIST SHOULD HAVE NO PROBLEM PRODUCING RAIN AND THUNDERSTORMS
LATE FRIDAY AND SATURDAY. COOLER AND DRIER AIR WILL FOLLOW SUNDAY.
09
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 81 58 83 57 / 0 0 0 0
HOBART OK 83 57 85 57 / 0 0 0 0
WICHITA FALLS TX 85 59 88 59 / 0 0 0 0
GAGE OK 84 52 82 55 / 20 0 0 0
PONCA CITY OK 80 57 81 55 / 10 10 0 0
DURANT OK 84 59 88 59 / 0 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
04/09
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1054 AM EDT MON SEP 23 2013
.SYNOPSIS...
UPPER LVL PATTERN WILL FEATURE AN OMEGA BLOCK THRU THIS
WEEK...WITH HIGH PRESSURE RIDGE CENTERED OVER PENNSYLVANIA. BLOCK
WILL LIKELY BREAK DOWN BY LATE NEXT WEEKEND...WHEN A COLD FRONT
WILL APPROACH FROM THE WEST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STUBBORN STRATOCUMULUS IS ONCE AGAIN OUR NEMESIS THIS MORNING AS
THE PROMISING BACK CLOUD EDGE DROPPING SOUTH FROM THE FINGERLAKES
HAS NOW FILLED IN BEHIND WITH SHALLOW BUT WIDESPREAD CUMULUS
STREETS FROM THE PA BORDER NORTHWARD THROUGH THE FINGERLAKES AND
LAKE ONTARIO. ADVECTION DOES NOT REVERSE UNTIL AFTER 18Z AND THINK
WE WON`T SEE SUBSTANTIAL CLEARING UNTIL THEREAFTER GIVEN SATELLITE
TRENDS AND WARM ADVECTION DELAYED UNTIL THE MID TO LATE AFTERNOON
HOURS.
NEAR TERM MESO MODELS HAVE HAD GREAT DIFFICULTY SINCE YESTERDAY...
BUT RAP MAY BE DOING THE BEST SHOWING THE THICKEST CLOUD COVER
ERODING FROM SOUTHEAST TO NORTHWEST. THIS DRYING FEATURE CAN
CLEARLY BE SEEN ON THE MORNING VIS LOOP AND SO THE LOWER SUSQ WILL
SEE THE MOST SUN TODAY. THE MID TO LATE AFTERNOON SHOULD BECOME
MOSTLY SUNNY FOR A MAJORITY OF CENTRAL PA AS THE SUBSIDENCE INVERSION
LOWERS/WEAKENS UPON APPROACH OF SFC HIGH. AS PREVIOUSLY MENTIONED...
ENS MEAN 925 MB TEMPS SUPPORT HIGH TEMPS FROM THE UPPER 50S OVR
THE NW MTNS...TO THE UPPER 60S SOUTHEAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
CLEAR SKIES...A CALM WIND AND DRY AIR WILL SET THE STAGE FOR A
COLD NIGHT...WITH AREAS OF FROST LIKELY ACROSS THE N MTNS. SOME OF
THE COLDER VALLEYS WILL LIKELY SEE A FREEZE...BUT NOT SURE
COVERAGE ENOUGH TO WARRANT A FREEZE WARNING. ATTM...GEFS PROBABILITY
GRAPHIC SUGGESTS SUB-FREEZING READINGS WILL BE LOCALIZED...SO HAVE
ISSUED ADVISORY FOR THE HIGH PROB OF FROST AND WILL LET DAY SHIFT
MAKE ANY NECESSARY UPGRADES.
AFTER A CHILLY START WITH LOWS IN THE L30S TO L40S...ABUNDANT
SUNSHINE SHOULD PUSH TEMPS TO SEASONAL LEVELS BY TUE AFTN. GEFS
MEAN 925 TEMPS IMPLY HIGH TEMPS WILL RANGE FROM THE M60S NW
MTNS...TO L70S SUSQ VALLEY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
00Z GEFS AND ECMWF ENSEMBLE DATA BOTH INDICATE PA WILL BE UNDER
RIDGE PORTION OF OMEGA BLOCK...RESULTING IN AN EXTENDED PERIOD OF
FAIR WEATHER LASTING INTO NEXT WEEKEND. GEFS 925/850 TEMPS INDICATE
DAYTIME TEMPS WILL BE NEAR TO A BIT ABV NORMAL...IN PART DUE TO
ABUNDANT SUNSHINE. HOWEVER...DRY AIR AND PROXIMITY OF SFC HIGH
WILL LIKELY PRODUCE SOME COOL MORNINGS. EVENTUAL BREAK DOWN OF BLOCK
WILL LIKELY PUSH A COLD FRONT TOWARD PA LATE IN THE
WEEKEND...ACCOMPANIED BY THE NEXT CHC OF SHOWERS.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
A LAYER OF STRATOCU REMAINS AS COLDER AIR CONTINUES TO ADVECT
INTO THE REGION. CIGS WILL REMAIN ABOVE 3000FT...EXCEPT MVFR CIGS
WILL PERSIST IN UPSLOPE FLOW ACROSS HIGHER ELEVATIONS OF THE NORTH
AND WEST /KBFD TO KJST AND POSS KAOO/.
LINGERING STRATOCU ACROSS THE N AND W WILL DECREASE DURING THE
EARLY AFTERNOON... MARKING THE BEGINNING OF AN EXTENDED PERIOD OF
WIDESPREAD VFR CONDITIONS /EXCEPT FOR SOME PATCHY EARLY MORNING
FOG/.
OUTLOOK...
TUE-FRI...MAINLY VFR...BUT SCT MVFR TO IFR IN AM FOG POSS EACH
DAY...INCREASING LATER IN THE WEEK AS DEWPOINTS RISE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 3 AM TO 9 AM EDT TUESDAY FOR PAZ004>006-
010-011-037.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...DEVOIR/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1050 AM EDT MON SEP 23 2013
.SYNOPSIS...
UPPER LVL PATTERN WILL FEATURE AN OMEGA BLOCK THRU THIS
WEEK...WITH HIGH PRESSURE RIDGE CENTERED OVER PENNSYLVANIA. BLOCK
WILL LIKELY BREAK DOWN BY LATE NEXT WEEKEND...WHEN A COLD FRONT
WILL APPROACH FROM THE WEST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STUBBORN STRATOCUMULUS IS ONCE AGAIN OUR NEMESIS THIS MORNING AS
THE PROMISING BACK CLOUD EDGE DROPPING SOUTH FROM THE FINGERLAKES
HAS NOW FILLED IN BEHIND WITH SHALLOW BUT WIDESPREAD CUMULUS
STREETS FROM THE PA BORDER NORTHWARD THROUGH THE FINGERLAKES AND
LAKE ONTARIO. ADVECTION DOES NOT REVERSE UNTIL AFTER 18Z AND THINK
WE WON`T SEE SUBSTANTIAL CLEARING UNTIL THEREAFTER GIVEN SATELLITE
TRENDS AND WARM ADVECTION DELAYED UNTIL THE MID TO LATE AFTERNOON
HOURS.
NEAR TERM MESO MODELS HAVE HAD GREAT DIFFICULTY SINCE YESTERDAY...
BUT RAP MAY BE DOING THE BEST SHOWING THE THICKEST CLOUD COVER
ERODING FROM SOUTHEAST TO NORTHWEST. THIS DRYING FEATURE CAN
CLEARLY BE SEEN ON THE MORNING VIS LOOP AND SO THE LOWER SUSQ WILL
SEE THE MOST SUN TODAY. THE MID TO LATE AFTERNOON SHOULD BECOME
MOSTLY SUNNY FOR A MAJORITY OF CENTRAL PA AS THE SUBSIDENCE INVERSION
LOWERS/WEAKENS UPON APPROACH OF SFC HIGH. AS PREVIOUSLY MENTIONED...
ENS MEAN 925 MB TEMPS SUPPORT HIGH TEMPS FROM THE UPPER 50S OVR
THE NW MTNS...TO THE UPPER 60S SOUTHEAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
CLEAR SKIES...A CALM WIND AND DRY AIR WILL SET THE STAGE FOR A
COLD NIGHT...WITH AREAS OF FROST LIKELY ACROSS THE N MTNS. SOME OF
THE COLDER VALLEYS WILL LIKELY SEE A FREEZE...BUT NOT SURE
COVERAGE ENOUGH TO WARRANT A FREEZE WARNING. ATTM...GEFS PROBABILITY
GRAPHIC SUGGESTS SUB-FREEZING READINGS WILL BE LOCALIZED...SO HAVE
ISSUED ADVISORY FOR THE HIGH PROB OF FROST AND WILL LET DAY SHIFT
MAKE ANY NECESSARY UPGRADES.
AFTER A CHILLY START WITH LOWS IN THE L30S TO L40S...ABUNDANT
SUNSHINE SHOULD PUSH TEMPS TO SEASONAL LEVELS BY TUE AFTN. GEFS
MEAN 925 TEMPS IMPLY HIGH TEMPS WILL RANGE FROM THE M60S NW
MTNS...TO L70S SUSQ VALLEY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
00Z GEFS AND ECMWF ENSEMBLE DATA BOTH INDICATE PA WILL BE UNDER
RIDGE PORTION OF OMEGA BLOCK...RESULTING IN AN EXTENDED PERIOD OF
FAIR WEATHER LASTING INTO NEXT WEEKEND. GEFS 925/850 TEMPS INDICATE
DAYTIME TEMPS WILL BE NEAR TO A BIT ABV NORMAL...IN PART DUE TO
ABUNDANT SUNSHINE. HOWEVER...DRY AIR AND PROXIMITY OF SFC HIGH
WILL LIKELY PRODUCE SOME COOL MORNINGS. EVENTUAL BREAK DOWN OF BLOCK
WILL LIKELY PUSH A COLD FRONT TOWARD PA LATE IN THE
WEEKEND...ACCOMPANIED BY THE NEXT CHC OF SHOWERS.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
A LAYER OF STRATOCU REMAINS AS COLDER AIR CONTINUES TO ADVECT
INTO THE REGION. CIGS WILL REMAIN ABOVE 3000FT...EXCEPT MVFR CIGS
WILL PERSIST IN UPSLOPE FLOW ACROSS HIGHER ELEVATIONS OF THE NORTH
AND WEST /KBFD TO KJST AND POSS KAOO/.
LINGERING STRATOCU ACROSS THE N AND W WILL DIMINISH AFTER SUNRISE
AS NORTHERLY FLOW WEAKENS...MARKING THE BEGINNING OF AN EXTENDED
PERIOD OF WIDESPREAD VFR CONDITIONS /EXCEPT FOR SOME PATCHY
EARLY MORNING FOG/.
OUTLOOK...
TUE-FRI...MAINLY VFR...BUT SCT MVFR TO IFR IN AM FOG POSS EACH
DAY...INCREASING LATER IN THE WEEK AS DEWPOINTS RISE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM 3 AM TO 9 AM EDT TUESDAY FOR PAZ004>006-
010-011-037.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...RXR
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1228 PM CDT MON SEP 23 2013
.UPDATE...
SEE UPDATED AVIATION DISCUSSION BELOW.
THE COLD FRONT CURRENTLY EXTENDS ACROSS SOUTH DAKOTA...ALONG A
LINE FROM ABOUT HETTINGER...TO FAITH...TO PINE RIDGE. ALL
ASSOCIATED PRECIPITATION IS POST FRONTAL AT THIS POINT...AND IS
PROGRESSING MUCH SLOWER THAN ORIGINALLY ANTICIPATED. MODELS DO
SHOW A WEAK SURGE IN THE AREAL EXTENT OF PRECIP AS ADDITIONAL UPPER
LEVEL SUPPORT AND INCREASED MID LEVEL FRONTOGENESIS OCCUR THIS
AFTERNOON. HOWEVER...BESIDES THE FAR WESTERN SECTION OF CORSON
COUNTY...THE UPDATED FORECAST DOES NOT HAVE POPS ENTERING INTO OUR
CWA UNTIL THE AFTERNOON HOURS. THE SYSTEM WEAKENS AND THE EASTERN
EXTENT OF PRECIP IS STILL UP IN THE AIR AT THIS POINT. BECAUSE OF
THE DELAYED TIMING...THE EASTERN 2/3 OF THE CWA WILL EXPERIENCE
PRETTY MUCH AN ENTIRE DAY OF SUNSHINE AND WARM AIR
ADVECTION...AND THEREFORE BUMPED UP THE AFTERNOON HIGH
TEMPERATURES SEVERAL DEGREES. THE EASTERN HALF OF THE CWA SHOULD
EXCEED 80 DEGREES TODAY.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH WEDNESDAY
WATER VAPOR IMAGERY SHOWS THE UPPER LOW OVER COLORADO EARLY THIS
MORNING. AT THE SURFACE...FRONTAL BOUNDARY IS LOCATED ACROSS
WESTERN SOUTH DAKOTA. SCATTERED SHOWERS HAVE BEEN OCCURRING ACROSS
WESTERN SOUTH DAKOTA AND OVER THE EXTREME NORTHWEST CWA OVER THE
PAST SEVERAL HOURS...BUT RADAR RETURNS ARE DIMINISHING AT THIS
TIME. AHEAD OF THE FRONT...BREEZY/GUSTY SOUTHERLY WINDS CONTINUE
OVER MUCH OF THE CWA WITH TEMPS STILL VERY MILD.
AS THE UPPER LOW KICKS OUT INTO THE PLAINS LATER THIS MORNING...A
REGENERATION OF SHOWERS AND STORMS IS EXPECTED OVER THE WESTERN
DAKOTAS. THE LATEST RUN OF THE HRRR AND THE 00Z NSSL WRF SHOW
WESTERN SOUTH DAKOTA SEEING THE BULK OF THE ACTIVITY THROUGH THE
MORNING HOURS...WITH CENTRAL SOUTH DAKOTA HOLDING OFF UNTIL THE
AFTERNOON. WILL HAVE TO WAIT FOR THE UPPER LOW TO GET CLOSER TO
THE AREA IT APPEARS FOR RAINFALL CHANCES TO INCREASE. 00Z NSSL WRF
INDICATES SHOWER AND THUNDERSTORM ACTIVITY DEVELOPING BETWEEN THE
MISSOURI AND JAMES RIVERS BY AROUND 21Z. ALL MODELS INDICATING
THAT THIS SYSTEM WILL WEAKEN AS IT CONTINUES MOVING EAST...WITH
BAND OF RAINFALL DISSIPATING AND BECOMING MORE WIDELY SCATTERED AS
IT MOVES EAST OF THE JAMES VALLEY. HAVE CONSTRUCTED WX/POP GRIDS
TO REFLECT THIS THINKING AND KEPT HIGHEST POPS OVER THE WESTERN
CWA THROUGHOUT THE DAY.
WITH THE SLOWER MOVEMENT OF THE UPPER LOW AND SURFACE
FRONT...HAVE INCREASED HIGHS A COUPLE DEGREES OVER THE EASTERN CWA
WHERE SOUTHERLY WINDS WILL REMAIN AND 850MB TEMPS STAY THE
WARMEST. SPEAKING OF WINDS...EXPECT ANOTHER WINDY DAY FOR THE
EASTERN COUNTIES...BUT LIKELY STAYING BELOW ADVISORY LEVELS.
TUESDAY AND TUESDAY NIGHT WILL BE QUIET AS A WEAK SURFACE RIDGE
SLIDES EAST OVER THE AREA. LOOK FOR MILD TEMPS AND DRY CONDITIONS.
WINDS BEGIN TO INCREASE AGAIN BY WEDNESDAY AS ANOTHER LOW PRESSURE
SYSTEM DEVELOPS TO THE WEST OF THE REGION.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
MAIN FCST CHALLENGE FACING THE EXTENDED PORTION OF FORECAST
REVOLVES AROUND PCPN CHANCES HEADING INTO THE WEEKEND...AND TEMPS
FOR NEXT WEEKEND.
MODELS CONT TO ADVERTISE A LONG WAVE TROF MOVING INTO THE INTERMTN
STATES TO BEGIN THE EXTENDED FOR THE WEDNESDAY NIGHT PERIOD. GOOD
MID LEVEL WAA AHEAD OF THIS TROF AS INDICATED BY 700HPA THETA-E
FORCING. HOWEVER...BOTH GFS AND LATEST EC SUGGEST SFC WINDS WILL
BE MORE SERLY WHICH TYPICALLY ISN`T A GOOD WARMING WIND FOR THE
CWA. THIS WILL PROBABLY HELP TO TEMPER HIGHS SOMEWHAT FROM WHAT
THEY COULD BE GIVEN A SOUTH OR EVEN SW WIND. THE EC IS A BIT
SLOWER THAN GFS ON ARRIVAL OF PCPN...WAITING UNTIL CLOSER TO 12Z
FRIDAY FOR ONSET. THAT SAID...SINCE STILL LOOKING AT 5 DAYS
OUT...AM CONTENT TO LEAVE ALLBLEND GRID ALONE AND REFINE AS
SHORTER TERM MODELS BEGIN TO COVER THIS TIME FRAME.
WITH COLD FROPA DURING THE DAY FRIDAY WITH PLENTY OF EXPECTED
CLOUD COVER...COOLISH TEMPS FRIDAY/SATURDAY SEEM
REALISTIC...ESPECIALLY WITH BOTH GFS AND EC SHOWING 850HPA TEMPS
IN THE +4C TO +6C RANGE. WAA RETURNS IN EARNEST FOR SUNDAY..SO
FORECAST HIGHS ABOUT A CATEGORY WARMER THAN SATURDAY ALSO SEEMS
PLAUSIBLE.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
SCATTERED RAIN SHOWERS WILL MOVE OVER THE FAR WESTERN CWA DURING
THE LATE AFTERNOON AND EVENING HOURS. AT THIS TIME...IT APPEARS
THAT CIGS AND VSBYS WILL REMAIN VFR WITH THE RAIN AS IT AFFECT
KMBG AND KPIR. LITTLE IN THE WAY OF RAINFALL IS EXPECTED AT KABR
AND KATY WHERE DRIER AIR WILL BE IN PLACE. SKIES WILL CLEAR BY
TUESDAY MORNING. SOUTHERLY WINDS OF 15 TO 30 MPH THIS AFTERNOON
WILL DIMINISH AND BECOME LIGHT AFTER SUNSET.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...SERR
SHORT TERM...TMT
LONG TERM...HINTZ
AVIATION...PARKIN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1053 AM CDT MON SEP 23 2013
.UPDATE...
THE COLD FRONT CURRENTLY EXTENDS ACROSS SOUTH DAKOTA...ALONG A
LINE FROM ABOUT HETTINGER...TO FAITH...TO PINE RIDGE. ALL
ASSOCIATED PRECIPITATION IS POST FRONTAL AT THIS POINT...AND IS
PROGRESSING MUCH SLOWER THAN ORIGINALLY ANTICIPATED. MODELS DO
SHOW A WEAK SURGE IN THE AREAL EXTENT OF PRECIP AS ADDITIONAL UPPER
LEVEL SUPPORT AND INCREASED MID LEVEL FRONTOGENESIS OCCUR THIS
AFTERNOON. HOWEVER...BESIDES THE FAR WESTERN SECTION OF CORSON
COUNTY...THE UPDATED FORECAST DOES NOT HAVE POPS ENTERING INTO OUR
CWA UNTIL THE AFTERNOON HOURS. THE SYSTEM WEAKENS AND THE EASTERN
EXTENT OF PRECIP IS STILL UP IN THE AIR AT THIS POINT. BECAUSE OF
THE DELAYED TIMING...THE EASTERN 2/3 OF THE CWA WILL EXPERIENCE
PRETTY MUCH AN ENTIRE DAY OF SUNSHINE AND WARM AIR
ADVECTION...AND THEREFORE BUMPED UP THE AFTERNOON HIGH
TEMPERATURES SEVERAL DEGREES. THE EASTERN HALF OF THE CWA SHOULD
EXCEED 80 DEGREES TODAY.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH WEDNESDAY
WATER VAPOR IMAGERY SHOWS THE UPPER LOW OVER COLORADO EARLY THIS
MORNING. AT THE SURFACE...FRONTAL BOUNDARY IS LOCATED ACROSS
WESTERN SOUTH DAKOTA. SCATTERED SHOWERS HAVE BEEN OCCURRING ACROSS
WESTERN SOUTH DAKOTA AND OVER THE EXTREME NORTHWEST CWA OVER THE
PAST SEVERAL HOURS...BUT RADAR RETURNS ARE DIMINISHING AT THIS
TIME. AHEAD OF THE FRONT...BREEZY/GUSTY SOUTHERLY WINDS CONTINUE
OVER MUCH OF THE CWA WITH TEMPS STILL VERY MILD.
AS THE UPPER LOW KICKS OUT INTO THE PLAINS LATER THIS MORNING...A
REGENERATION OF SHOWERS AND STORMS IS EXPECTED OVER THE WESTERN
DAKOTAS. THE LATEST RUN OF THE HRRR AND THE 00Z NSSL WRF SHOW
WESTERN SOUTH DAKOTA SEEING THE BULK OF THE ACTIVITY THROUGH THE
MORNING HOURS...WITH CENTRAL SOUTH DAKOTA HOLDING OFF UNTIL THE
AFTERNOON. WILL HAVE TO WAIT FOR THE UPPER LOW TO GET CLOSER TO
THE AREA IT APPEARS FOR RAINFALL CHANCES TO INCREASE. 00Z NSSL WRF
INDICATES SHOWER AND THUNDERSTORM ACTIVITY DEVELOPING BETWEEN THE
MISSOURI AND JAMES RIVERS BY AROUND 21Z. ALL MODELS INDICATING
THAT THIS SYSTEM WILL WEAKEN AS IT CONTINUES MOVING EAST...WITH
BAND OF RAINFALL DISSIPATING AND BECOMING MORE WIDELY SCATTERED AS
IT MOVES EAST OF THE JAMES VALLEY. HAVE CONSTRUCTED WX/POP GRIDS
TO REFLECT THIS THINKING AND KEPT HIGHEST POPS OVER THE WESTERN
CWA THROUGHOUT THE DAY.
WITH THE SLOWER MOVEMENT OF THE UPPER LOW AND SURFACE FRONT...HAVE
INCREASED HIGHS A COUPLE DEGREES OVER THE EASTERN CWA WHERE
SOUTHERLY WINDS WILL REMAIN AND 850MB TEMPS STAY THE WARMEST.
SPEAKING OF WINDS...EXPECT ANOTHER WINDY DAY FOR THE EASTERN
COUNTIES...BUT LIKELY STAYING BELOW ADVISORY LEVELS.
TUESDAY AND TUESDAY NIGHT WILL BE QUIET AS A WEAK SURFACE RIDGE
SLIDES EAST OVER THE AREA. LOOK FOR MILD TEMPS AND DRY CONDITIONS.
WINDS BEGIN TO INCREASE AGAIN BY WEDNESDAY AS ANOTHER LOW PRESSURE
SYSTEM DEVELOPS TO THE WEST OF THE REGION.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
MAIN FCST CHALLENGE FACING THE EXTENDED PORTION OF FORECAST
REVOLVES AROUND PCPN CHANCES HEADING INTO THE WEEKEND...AND TEMPS
FOR NEXT WEEKEND.
MODELS CONT TO ADVERTISE A LONG WAVE TROF MOVING INTO THE INTERMTN
STATES TO BEGIN THE EXTENDED FOR THE WEDNESDAY NIGHT PERIOD. GOOD
MID LEVEL WAA AHEAD OF THIS TROF AS INDICATED BY 700HPA THETA-E
FORCING. HOWEVER...BOTH GFS AND LATEST EC SUGGEST SFC WINDS WILL
BE MORE SERLY WHICH TYPICALLY ISN`T A GOOD WARMING WIND FOR THE
CWA. THIS WILL PROBABLY HELP TO TEMPER HIGHS SOMEWHAT FROM WHAT
THEY COULD BE GIVEN A SOUTH OR EVEN SW WIND. THE EC IS A BIT
SLOWER THAN GFS ON ARRIVAL OF PCPN...WAITING UNTIL CLOSER TO 12Z
FRIDAY FOR ONSET. THAT SAID...SINCE STILL LOOKING AT 5 DAYS
OUT...AM CONTENT TO LEAVE ALLBLEND GRID ALONE AND REFINE AS
SHORTER TERM MODELS BEGIN TO COVER THIS TIME FRAME.
WITH COLD FROPA DURING THE DAY FRIDAY WITH PLENTY OF EXPECTED
CLOUD COVER...COOLISH TEMPS FRIDAY/SATURDAY SEEM
REALISTIC...ESPECIALLY WITH BOTH GFS AND EC SHOWING 850HPA TEMPS
IN THE +4C TO +6C RANGE. WAA RETURNS IN EARNEST FOR SUNDAY..SO
FORECAST HIGHS ABOUT A CATEGORY WARMER THAN SATURDAY ALSO SEEMS
PLAUSIBLE.
MODELS CONTINUE TO BE IN RELATIVELY GOOD AGREEMENT ON LONG WAVE
PATTERN. A TROF WILL MOVE OUT OF THE PAC WEST TOWARD THE PLAINS BY
THE END OF THE WORK WEEK. EXACT TIMING AND PRECIP PLACEMENT DIFFER
SLIGHTLY SO STUCK CLOSE TO ALLBLEND. THIS PUTS POPS IN THE
FORECAST THURSDAY NIGHT THROUGH FRIDAY NIGHT...THOUGH TIMING WILL
LIKELY NEED TO BE REFINED AS MODELS GAIN A BETTER GRASP ON THE
SYSTEM.
TEMPERATURES AHEAD OF THE UPPER TROF WILL BE IN THE UPPER 70S.
BEHIND THE TROF TEMPS WILL FALL TO RIGHT AROUND NORMAL FOR LATE
SEPTEMBER.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDS ARE EXPECTED FOR THE VALID FORECAST PERIOD. AN ELONGATED
TROUGH OF LOW PRESSURE IS LOCATED FROM WESTERN ND INTO LOW
PRESSURE LOCATED IN NERN CO. THIS TROUGH WILL MOVE SLOWLY EAST
THROUGH THE VALID FORECAST PERIOD...WITH ISOLD/SCT -SHRA/-TSRA
POSSIBLE ALONG THE TROUGH. LOOK FOR STRONG SE WINDS TO CONT FOR
THE KATY/KABR TERMINALS THROUGH 00Z TUESDAY. LOOK FOR VCSH CONDS
TO SET UP FOR THE KPIR/KMBG TERMINALS AROUND 00Z TUESDAY. CIGS MAY
LOWER A BIT IN THE HEAVIER SHOWERS...BUT SHOULD REMAIN IN THE VFR
CATEGORY.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...SERR
SHORT TERM...TMT
LONG TERM...HINTZ
AVIATION...HINTZ
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
329 AM CDT MON SEP 23 2013
.SHORT TERM...TODAY THROUGH WEDNESDAY
WATER VAPOR IMAGERY SHOWS THE UPPER LOW OVER COLORADO EARLY THIS
MORNING. AT THE SURFACE...FRONTAL BOUNDARY IS LOCATED ACROSS
WESTERN SOUTH DAKOTA. SCATTERED SHOWERS HAVE BEEN OCCURRING ACROSS
WESTERN SOUTH DAKOTA AND OVER THE EXTREME NORTHWEST CWA OVER THE
PAST SEVERAL HOURS...BUT RADAR RETURNS ARE DIMINISHING AT THIS
TIME. AHEAD OF THE FRONT...BREEZY/GUSTY SOUTHERLY WINDS CONTINUE
OVER MUCH OF THE CWA WITH TEMPS STILL VERY MILD.
AS THE UPPER LOW KICKS OUT INTO THE PLAINS LATER THIS MORNING...A
REGENERATION OF SHOWERS AND STORMS IS EXPECTED OVER THE WESTERN
DAKOTAS. THE LATEST RUN OF THE HRRR AND THE 00Z NSSL WRF SHOW
WESTERN SOUTH DAKOTA SEEING THE BULK OF THE ACTIVITY THROUGH THE
MORNING HOURS...WITH CENTRAL SOUTH DAKOTA HOLDING OFF UNTIL THE
AFTERNOON. WILL HAVE TO WAIT FOR THE UPPER LOW TO GET CLOSER TO
THE AREA IT APPEARS FOR RAINFALL CHANCES TO INCREASE. 00Z NSSL WRF
INDICATES SHOWER AND THUNDERSTORM ACTIVITY DEVELOPING BETWEEN THE
MISSOURI AND JAMES RIVERS BY AROUND 21Z. ALL MODELS INDICATING
THAT THIS SYSTEM WILL WEAKEN AS IT CONTINUES MOVING EAST...WITH
BAND OF RAINFALL DISSIPATING AND BECOMING MORE WIDELY SCATTERED AS
IT MOVES EAST OF THE JAMES VALLEY. HAVE CONSTRUCTED WX/POP GRIDS
TO REFLECT THIS THINKING AND KEPT HIGHEST POPS OVER THE WESTERN
CWA THROUGHOUT THE DAY.
WITH THE SLOWER MOVEMENT OF THE UPPER LOW AND SURFACE FRONT...HAVE
INCREASED HIGHS A COUPLE DEGREES OVER THE EASTERN CWA WHERE
SOUTHERLY WINDS WILL REMAIN AND 850MB TEMPS STAY THE WARMEST.
SPEAKING OF WINDS...EXPECT ANOTHER WINDY DAY FOR THE EASTERN
COUNTIES...BUT LIKELY STAYING BELOW ADVISORY LEVELS.
TUESDAY AND TUESDAY NIGHT WILL BE QUIET AS A WEAK SURFACE RIDGE
SLIDES EAST OVER THE AREA. LOOK FOR MILD TEMPS AND DRY CONDITIONS.
WINDS BEGIN TO INCREASE AGAIN BY WEDNESDAY AS ANOTHER LOW PRESSURE
SYSTEM DEVELOPS TO THE WEST OF THE REGION.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY
MAIN FCST CHALLENGE FACING THE EXTENDED PORTION OF FORECAST
REVOLVES AROUND PCPN CHANCES HEADING INTO THE WEEKEND...AND TEMPS
FOR NEXT WEEKEND.
MODELS CONT TO ADVERTISE A LONG WAVE TROF MOVING INTO THE INTERMTN
STATES TO BEGIN THE EXTENDED FOR THE WEDNESDAY NIGHT PERIOD. GOOD
MID LEVEL WAA AHEAD OF THIS TROF AS INDICATED BY 700HPA THETA-E
FORCING. HOWEVER...BOTH GFS AND LATEST EC SUGGEST SFC WINDS WILL
BE MORE SERLY WHICH TYPICALLY ISN`T A GOOD WARMING WIND FOR THE
CWA. THIS WILL PROBABLY HELP TO TEMPER HIGHS SOMEWHAT FROM WHAT
THEY COULD BE GIVEN A SOUTH OR EVEN SW WIND. THE EC IS A BIT
SLOWER THAN GFS ON ARRIVAL OF PCPN...WAITING UNTIL CLOSER TO 12Z
FRIDAY FOR ONSET. THAT SAID...SINCE STILL LOOKING AT 5 DAYS
OUT...AM CONTENT TO LEAVE ALLBLEND GRID ALONE AND REFINE AS
SHORTER TERM MODELS BEGIN TO COVER THIS TIME FRAME.
WITH COLD FROPA DURING THE DAY FRIDAY WITH PLENTY OF EXPECTED
CLOUD COVER...COOLISH TEMPS FRIDAY/SATURDAY SEEM
REALISTIC...ESPECIALLY WITH BOTH GFS AND EC SHOWING 850HPA TEMPS
IN THE +4C TO +6C RANGE. WAA RETURNS IN EARNEST FOR SUNDAY..SO
FORECAST HIGHS ABOUT A CATEGORY WARMER THAN SATURDAY ALSO SEEMS
PLAUSIBLE.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
A FEW SHOWERS AND THUNDERSTORMS ARE POSSIBLE WEST OF THE MISSOURI
RIVER DURING THE OVERNIGHT HOURS. NO SEVERE WEATHER IS EXPECTED
AND NO TAF SITES ARE EXPECTED TO BE AFFECTED. THE WESTERN HALF OF
THE CWA WILL SEE A CHANCE FOR RAIN SHOWERS AGAIN DURING THE
LATE AFTERNOON AND EVENING HOURS ON MONDAY. SOUTHERLY WINDS WILL
REMAIN IN THE 15 TO 30 MPH RANGE. CIGS AND VSYBS WILL GENERALLY
REMAIN IN THE VFR CATEGORY...BUT COULD DROP A BIT LOWER WITH ANY
HEAVIER SHOWERS THAT MAY DEVELOP MONDAY EVENING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...TMT
LONG TERM...HINTZ
AVIATION...HINTZ
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1136 AM PDT Mon Sep 23 2013
.SYNOPSIS...
Cooler air behind a cold front which moved through last night will
drop temperatures below normal for most of the week with a threat
of showers through Wednesday. The weather will then dry out with a
gradual warming trend through next weekend.
&&
.DISCUSSION...
Remainder of today...Swift west-southwest upper level jet has
shifted into eastern Washington late this morning and extended
from the NW Oregon coast toward Mullan Pass. For the most part
this has delivered a drying trend to much of the region...with
most of the residual showers persisting either near the Cascade
Crest over over the northern half of the Idaho Panhandle. The
question for later today is will the showers become more numerous
through the day. If the short range model solutions are on
track...we should see a rapid growth in showers especially over NE
Washington and the northern half of the ID Panhandle as these areas
are situated under the favorable left front quadrant of the upper
level jet. Meanwhile any diurnal heating should result in a quick
destabilization of the atmosphere. The question is will the
instability be deep enough to produce showers. Over the Columbia Basin
the answer is probably no as there is still a lot of downslope
westerly flow to overcome off the Cascades. Meanwhile The same
west- southwest flow low/mid atmosphere flow should bring good
orographical ascent to the NE corner of Washington and the
Panhandle. The only fly in the ointment is the HRRR model is not
depicting much threat of showers anywhere this afternoon until
after 22z...and even then its quite limited. Usually its wise to
follow its trends...however its underplaying the current batch of
showers currently situated over eastern Shoshone County...so we
will ignore for now. fx
&&
.AVIATION...
18Z TAFS: VFR conditions expected though much of the period aside
from some brief MVFR conditions through 20-21z or so around KGEG-
KCOE due to a small area of stratocumulus which recently formed
over the area. This cloud deck should rise into 3500-5000 ft range
as daytime heating continues into the afternoon. These sites also
will see a small risk of showers aft 21z due in part to the
daytime heating. We do not expect to see anything more than very
light rain. For tonight all locations will experience vfr
conditions until a weak warm front moves into SE WA and NC ID aft
10z or so. Cigs will lower steadily in advance of the front...and
MVFR heights are a good possibility. The question is how soon will
they lower to these levels. For now we went with after 15z...but
that could prove a little too late if front moves in quicker than
expected. fx
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 62 45 59 42 59 43 / 20 20 50 30 20 10
Coeur d`Alene 61 45 58 42 57 42 / 20 20 60 30 30 10
Pullman 63 45 57 40 58 40 / 10 40 70 40 30 10
Lewiston 70 52 60 48 64 46 / 10 30 70 60 40 30
Colville 64 44 62 41 64 40 / 30 20 30 40 20 10
Sandpoint 57 43 55 37 55 38 / 40 40 50 50 30 20
Kellogg 57 44 55 40 54 40 / 40 60 70 60 30 30
Moses Lake 69 47 66 44 68 44 / 10 10 30 20 10 0
Wenatchee 66 48 65 47 66 47 / 10 10 20 30 30 0
Omak 66 42 65 42 66 42 / 10 10 20 20 10 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
610 PM CDT TUE SEP 24 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 256 CDT TUE SEP 24 2013
MINIMAL WEATHER IMPACTS FOR THE AREA UNTIL THE PASSAGE OF COLD
FRONT THIS WEEKEND. FOR THIS AFTERNOON...WATER VAPOR IMAGERY
OVERLAID WITH RAP 500 MB HEIGHTS CONTINUES TO SHOW DECAYING UPPER
LEVEL SHORTWAVE TROUGH ACROSS IOWA...WHICH HAS SPREAD MID/HIGH
LEVEL CLOUDS ACROSS NORTHEAST IOWA INTO SOUTHEAST MINNESOTA. A
DOWNSTREAM UPPER LEVEL RIDGE IS HOLDING STRONG...HELPING TO KEEP
THE DRY AIR MASS IN PLACE...AS SEEN BY THE 24.12Z MPX/GRB
SOUNDINGS.
FOR TONIGHT...THE SURFACE HIGH PRESSURE REMAINS TO OUR EAST AND
OVERALL THE SURFACE PRESSURE FIELDS ARE VERY BAGGY. FORECAST
SOUNDINGS INDICATE THAT THROUGH AROUND 400 MB THE WIND FIELD IS
LESS THAN 10 KTS. AS WAS THE CASE THIS MORNING...EXPECTING PATCHY
DENSE FOG TO DEVELOP ACROSS LOW LYING AREAS OF CENTRAL
WISCONSIN...AND POSSIBLY IN THE MS AND WISCONSIN RIVER VALLEYS.
THE MORE FAVORABLE SET UP EXISTS ACROSS CENTRAL WISCONSIN BUT
COULD NOT RULE PATCHY FOG ACROSS SOUTHEAST MINNESOTA AND NORTHEAST
IOWA DURING THE EARLY MORNING HOURS. OVERALL..THE MAIN LIMITING
FACTOR FOR A MORE WIDESPREAD DENSE EVENT LOOKS TO BE THE LACK OF
SATURATION IN THE BOUNDARY LAYER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 256 CDT TUE SEP 24 2013
SOUTHWESTERLY FLOW SETS UP WEDNESDAY THROUGH THE END OF THE WORK
WEEK AS THE UPPER LEVEL PATTERN BECOMES AMPLIFIED...PROVIDING A FEW
PLEASANT AND TRANQUIL EARLY AUTUMN DAYS. A WESTERN SHORTWAVE TROUGH
BEGINS TO DIG AND MOVE EASTWARD WHILE THE DOWNSTREAM RIDGE BUILDS
ACROSS MUCH OF THE EASTERN CONUS. MOSTLY SUNNY TO SUNNY SKIES
SHOULD PREVAIL EACH DAY...WITH A GRADUAL WARMING IN HIGH
TEMPERATURES. HIGHS RANGING FROM THE LOW TO MID 70S WEDNESDAY WILL
WARM TO THE UPPER 70S TO LOWER 80S BY FRIDAY.
THE 24.12Z MODEL GUIDANCE MORE OR LESS DID NOT CHANGE THE SPEED AND
PROGRESSION OF THE WEEKEND WEATHER SYSTEM...MAYBE A TOUCH FASTER
COMPARED TO THE 00Z AND 06Z RUNS. HOWEVER...THERE IS BETTER
AGREEMENT BETWEEN THE VARIOUS DETERMINISTIC MODELS THAN PREVIOUS
MODEL CYCLES. IT APPEARS THAT THROUGH 15Z SATURDAY THE FORECAST
AREA SHOULD BE DRY WITH INCREASING MID TO HIGH LEVEL CLOUDS.
INITIAL PRECIPITATION BAND LOOKS TO SPREAD IN FROM THE WEST DURING
THE LATE MORNING HOURS...MOVING INTO WESTERN WISCONSIN DURING THE
EARLY/MID AFTERNOON. THE 24.12Z GFS REMAINS A BIT FASTER THAN THE
24.12Z GEM...WHILE THE 24.12Z CONTINUES TO BE SLOWER SOLUTION. THE
24.12Z ECMWF ATTEMPTS TO TURN THE UPPER LEVEL WAVE MORE NEGATIVELY
TILTED SATURDAY AFTERNOON...HELPING TO PUSH THE WHOLE SYSTEM EAST
OF THE AREA BY EARLY SUNDAY...IN LINE WITH ITS FASTER
COUNTERPARTS. THIS SUGGESTS GOOD CONSISTENCY FOR A DRY
SUNDAY...SO HAVE REMOVED CHANCES ALONG AND WEST OF THE MISSISSIPPI
RIVER.
IN THE WAKE OF THIS SYSTEM...ZONAL UPPER LEVEL FLOW WILL PROVIDE A
COUPLE OF DAYS OF NEAR NORMAL TEMPERATURES AND TRANQUIL WEATHER.
INDICATIONS IN THE 24.12Z ECMWF OF AN ACTIVE PACIFIC NORTHWEST JET
SUGGESTS PIECES OF FAST MOVING ENERGY THROUGH THE FLOW...WITH A
COLD FRONTAL PASSAGE TUESDAY NEXT WEEK FOLLOWED BY A REINFORCING
SHOT OF COOLER AIR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 610 PM CDT TUE SEP 24 2013
FOG DEVELOPED UNDER THE CENTER OF THE SFC HIGH EARLY THIS
MORNING...WITH WIDESPREAD VSBY REDUCTIONS ACROSS MOST OF
CENTRAL/EASTERN WI. WEST OF THERE...PRESSURE GRADIENT KEPT SFC/NEAR
SFC WINDS STIRRED MORE...PREVENTING ANY WIDESPREAD FOG DEVELOPMENT.
TONIGHT...PRESSURE GRADIENT LOOKS TO BE MORE LAX FOR THE ENTIRE
AREA...ALTHOUGH SOME HINTS IN THE BUFKIT SOUNDINGS THAT WINDS OFF
THE SFC QUICKLY INCREASE TO 10+ KTS. EXPECT SOME BR TO DEVELOP
OVERNIGHT...FAVORING MVFR 3-5SM. THAT SAID...THERE IS A THREAT FOR
SUB 1SM...ESPECIALLY IN THE RIVER VALLEYS. THE 23Z T/TD IS NOT
NECESSARILY GOOD OR BAD FOR DENSE FOG FORMATION...WHILE WINDS SPEEDS
GENERALLY FAVOR IT. CONFIDENCE SHAKY...SO WILL STICK WITH THE MVFR
VSBYS FOR NOW.
OUTSIDE THE FOG THREAT...EXPECT VFR CONDITIONS TONIGHT THROUGH
WEDNESDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZT
LONG TERM....ZT
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
258 PM CDT MON SEP 23 2013
.SYNOPSIS...
ISSUED AT 258 PM CDT MON SEP 23 2013
THE INFLUENCE OF HIGH PRESSURE WILL KEEP THE UPPER MISSISSIPPI
RIVER VALLEY DRY THIS WEEK...AND ALLOW TEMPERATURES TO GRADUALLY
WARM FROM NORMAL TO SLIGHTLY ABOVE NORMAL READINGS BY THURSDAY
AND FRIDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 258 PM CDT MON SEP 23 2013
AFTERNOON WATER VAPOR IMAGERY OVERLAID WITH RAP 500 MB ANALYSIS
SHOWS RATHER DEEP NEGATIVELY TITLED UPPER LEVEL SHORTWAVE TROUGH
EJECTING OUT INTO THE CENTRAL PLAINS. AT THE SURFACE...A 997 MB
LOW RESIDES IN NW KANSAS WITH A NICE CURL SEEN IN VISIBLE
SATELLITE IMAGERY. IT IS THIS SYSTEM THAT WILL BE LIFTING TOWARD
THE UPPER MIDWEST TONIGHT INTO TUESDAY.
23.12Z GUIDANCE REMAINS SUPPORTIVE OF A DRY FORECAST WITH THIS
SYSTEM AS A COMBINATION OF WEAKENING DYNAMICS AND LIMITED
MOISTURE TRANSPORT LEAVES A LOT TO BE DESIRED. ACROSS THE
BOARD...500-300 MB PV ADVECTION...300-310K ISENTROPIC LIFT...AND
850 MB MOISTURE TRANSPORT ALL WEAKEN OR BECOME NON-EXISTENT
BETWEEN 06Z AND 15Z TUESDAY. OUTSIDE OF MID TO HIGH LEVEL CLOUDS
SPREADING IN FROM THE WEST INITIALLY WITH THE WARM AIR ADVECTION
WING...LITTLE TO NO IMPACT EXPECTED WITH THIS SYSTEM. PLAN ON
ANOTHER PLEASANT AUTUMN DAY WITH MOSTLY TO PARTLY SUNNY SKIES AND
HIGHS A COUPLE DEGREES ON EITHER SIDE OF 70F.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 258 PM CDT MON SEP 23 2013
DRY/QUIET WEATHER TUESDAY NIGHT THROUGH FRIDAY AS RIDGE OF HIGH
PRESSURE INFLUENCES THE SENSIBLE WEATHER ACROSS THE UPPER MIDWEST.
BY WEDNESDAY...THE AFOREMENTIONED SYSTEM DECAYS AND SLOWS ACROSS
THE MID ATLANTIC MEANWHILE A WESTERN CONUS SHORTWAVE TROUGH DIGS
DOWN NEAR THE FOUR CORNERS REGION. THIS PUTS THE CENTRAL PLAINS
UNDER DRY...WARMING SOUTHWESTERLY FLOW. 925 MB TEMPERATURES ARE
EXPECTED TO CLIMB EACH DAY...FROM NEAR SEASONAL LEVELS WEDNESDAY
TO SLIGHTLY ABOVE NORMAL BY THURSDAY...AND TO NEAR 80 IN SOME
SPOTS BY FRIDAY.
WEDNESDAY MORNING CONDITIONS LOOK SOMEWHAT FAVORABLE FOR RIVER
VALLEY FOG AS HIGH PRESSURE CENTERS ITSELF ACROSS CENTRAL
WISCONSIN. FORECAST SOUNDINGS SHOW A VERY DEEP LAYER OF LIGHT
WINDS LESS THAN 10 KTS UP TO 600 MB...THOUGH THERE IS A LACK OF
LOW LEVEL SATURATION...BUT COULD BE ENOUGH TO PATCHY RIVER VALLEY
FOG. THE OTHER COMPETING FACTOR IS THE POSSIBILITY OF A
NORTH/SOUTH ORIENTED MID LEVEL STRATUS DECK SETTING UP ALONG OR
JUST WEST OF THE MS RIVER. THIS IS SEEN IN THE GFS/NAM RH FIELDS
AT 850 AND 700 MB. FOR NOW...HAVE ADDED PATCHY VALLEY FOG TO MS
AND WISCONSIN RIVER VALLEYS.
FOCUS TURNS TO LATE FRIDAY NIGHT INTO THE UPCOMING WEEKEND SYSTEM
AS THE WESTERN SHORTWAVE TROUGH MOVES INTO THE NORTHERN AND
CENTRAL PLAINS. AS PIECES OF ENERGY ROUND THE SHORTWAVE TROUGH...A
COUPLE OF SURFACE LOWS ARE EXPECTED TO FORM...AND EVENTUALLY DRAG
A COLD FRONT THROUGH THE AREA. MOISTURE AHEAD OF THE FRONT
INCREASES...AND BROAD BUT PERSISTENT ISENTROPIC LIFT ON THE
305-315K SURFACES IS SEEN. THERE IS WEAK INSTABILITY ASSOCIATED
WITH THE SYSTEM...BUT MOST OF THE PRECIPITATION LOOKS TO BE POST-
FRONTAL. THE POSITIVE TILTED NATURE OF THE SHORTWAVE TROUGH MAKES
TIMING DETAILS A BIT UNCERTAIN AND DIFFICULT...AS THERE REMAINS
SOME DISAGREEMENT BETWEEN THE 23.12Z GUIDANCE. HOWEVER...ALL
GUIDANCE DID TREND MUCH SLOWER THAN PREVIOUS RUNS...THOUGH WITH
VARYING DEGREES. THE GEM/ECMWF SUGGESTS MOST OF SATURDAY WOULD
REMAIN DRY...HOLDING PRECIPITATION BACK UNTIL SATURDAY NIGHT OR
SUNDAY. THE GFS IS A TOUCH FASTER BUT STILL SLOWER THAN ITS
PREVIOUS RUN. AS A RESULT...HAVE PUSHED BACK PRECIPITATION
TIMING...ESPECIALLY EAST OF THE MISSISSIPPI RIVER. STILL PLENTY OF
TIME TO IRON OUT THE SPECIFICS. IN THE WAKE OF THIS SYSTEM...A
RETURN TO SEASONABLY COOL AND DRY WEATHER THANKS TO CANADIAN HIGH
PRESSURE BUILDING INTO THE UPPER MIDWEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1201 PM CDT MON SEP 23 2013
HIGH PRESSURE OVER THE GREAT LAKES WILL KEEP VFR WEATHER ACROSS THE
OHIO VALLEY THIS AFTERNOON AND EVENING WITH A LIGHT EAST TO
NORTHEAST BREEZE. DO EXPECT SCATTERED CLOUDS ABOUT 4-5 KFT WILL
DEVELOP OR MOVE IN AS MODEST MOISTURE RETURN BEGINS. BWG STANDS THE
BEST SHOT AT HAVING CEILINGS NEAR MVFR BY EARLY IN THE DAY ON
WEDNESDAY. MAY HAVE TO INCLUDE SOME VCSH AT SOME POINT ACROSS SOUTH
CENTRAL KENTUCKY FOR WEDNESDAY, BUT AM NOT CONFIDENT ENOUGH IN
COVERAGE AT THIS TIME TO MENTION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SYNOPSIS.....ZT
SHORT TERM...ZT
LONG TERM....ZT
AVIATION.....DAS
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1012 AM CDT MON SEP 23 2013
.UPDATE...SOUTHEASTERLY FLOW ALLOWING LAKE EFFECT LOW STRATUS
CLOUDS OVER THE LAKESHORE COUNTIES TO FILL IN TO BROKEN COVERAGE.
MODELS INDICATE THEY WILL PERSIST THROUGH MIDDAY. TEMPERATURES ARE
RUNNING A FEW DEGREES WARMER THAN YESTERDAY. 925MB TEMPS FORECAST
REACH 11C EAST TO 13-14 C IN SOUTH-CENTRAL WI. AS A RESULT HIGHS
ARE ON TRACK FOR MID 60S IN THE EAST TO AROUND 70 IN SOUTH-CENTRAL
WI.
&&
.AVIATION/18Z TAFS/...LAKE EFFECT CLOUDS CONTINUE TO BRING MVFR
CIGS TO THE EAST THIS MORNING. BASED ON LATEST NAM AND RAP 900 MB
RH...LOOKS LIKE THESE CLOUDS MAY HANG ON THROUGH THE REMAINDER OF
THE MORNING. EVEN IF CLOUDS ARE STILL BKN BY 18Z THOUGH...SHOULD
SEE ENOUGH MIXING BY TO RAISE BASES TO VFR. WILL LIKELY BE QUIET
THEN THROUGH THE REMAINDER OF THE DAY AND OVERNIGHT WITH HIGH
PRESSURE CENTERED OVER THE EASTERN GREAT LAKES.
MAY SEE ANOTHER ROUND OF LAKE EFFECT CLOUDS TOMORROW MORNING WITH
A SIMILAR AIRMASS IN PLACE. THE WIND FLOW LOOKS MORE SOUTHERLY
THAN TODAY THOUGH...SO NOT AS GOOD OF A SETUP AS THIS MORNING.
&&
.PREV DISCUSSION... /ISSUED 307 AM CDT MON SEP 23 2013/
TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH.
A N-S SFC TROUGH AND ACCOMPANIED UPPER TROUGH WILL MOVE EAST
ACROSS THE GREAT PLAINS TODAY...AND TRACK INTO THE LOWER TO
MIDDLE MO RIVER VALLEY LATER TNT. THE UPPER RIDGE OVER WI WILL
SLOWLY MOVE EAST WITH THE SFC RIDGE OVER THE ERN GREAT LAKES. A
SELY FLOW WILL PREVAIL...WITH FCST SOUNDINGS SHOWING THE
POTENTIAL FOR FEW-SCT LAKE EFFECT STRATOCUMULUS CLOUDS IN ERN WI
INCLUDING SOME DAYTIME CUMULUS AS WELL.
BUT FOR THE MOST PART...PLENTY OF SUNSHINE AND WEAK WARM ADVECTION
WILL BOOST 925 MB TEMPS INTO THE LOWER TO MID TEENS CELSIUS WHICH
YIELDS HIGHS IN THE MID TO UPPER 60S. LOW FOR TNT WILL BE A LITTLE
MILDER THAN THIS MORNING...WITH SOME DECOUPLING EXPECTED OVER THE
ERN CWA BUT AWAY FROM THE LAKE.
TUESDAY THROUGH WEDNESDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
SHORT TERM MODELS REMAIN IN GOOD AGREEMENT WITH FEATURES DURING
THIS PERIOD. THEY HAVE THE 500MB SHORTWAVE TROUGH WEAKENING AS IT
SLIDES TO THE EAST SOUTHEAST FROM EASTERN NEBRASKA/WESTERN IOWA TO
CENTRAL INDIANA TUESDAY AND TUESDAY NIGHT. THIS FEATURE TAKES MOST
OF THE MIDDLE TO UPPER LEVEL MOISTURE WITH IT IN THIS
DIRECTION...MAINLY MISSING SOUTHERN WISCONSIN. 500MB RIDGE THEN
BUILDS IN ACROSS THE WESTERN GREAT LAKES REGION WEDNESDAY AND
WEDNESDAY NIGHT.
AT THE SURFACE...HIGH PRESSURE REMAINS NORTHEAST OF THE REGION
TUESDAY INTO WEDNESDAY NIGHT. ALL OF THIS RESULTS IN QUIET WEATHER
CONTINUING THIS TIME. TEMPERATURES WILL CONTINUE TO SLOWLY
WARM...WITH 925MB TEMPERATURES SUPPORTING UPPER 60S TO LOWER 70S
AWAY FROM THE LAKE TUESDAY AND WEDNESDAY. LOWS WILL RISE INTO THE
UPPER 40S AWAY FROM THE LAKE EACH NIGHT...MILDER NEAR THE LAKE.
THURSDAY THROUGH SUNDAY...FORECAST CONFIDENCE IS MEDIUM TO HIGH.
GFS/ECMWF ARE IN FAIR AGREEMENT WITH FEATURES THURSDAY INTO
FRIDAY. THEY SHOW THE 500MB RIDGE SLOWLY SHIFTING EAST OF THE
REGION. SURFACE HIGH PRESSURE WILL REMAIN EAST OF THE
REGION...WITH ITS INFLUENCE STILL OVER THE AREA. QUIET WEATHER
WILL CONTINUE THURSDAY INTO FRIDAY...WITH TEMPERATURES CONTINUING
TO WARM ABOVE SEASONAL NORMALS.
THE GFS CONTINUES TO BE ABOUT 6 HOURS QUICKER WITH THE COLD
FRONTAL PASSAGE OVER THE AREA THAN THE ECMWF SATURDAY/SATURDAY
NIGHT. THE GFS BRINGS IT THROUGH SATURDAY...WITH THE ECMWF
SATURDAY EVENING. BOTH MODELS HAVE PRECIPITATION THROUGH THE AREA
BY 12Z SUNDAY...WITH SUNDAY DRY WITH HIGH PRESSURE MOVING INTO THE
REGION FROM THE WEST. FOR NOW...WILL USE CONSENSUS POPS AND
TEMPERATURES FRIDAY NIGHT INTO SUNDAY.
AVIATION/12Z TAFS/...VFR CONDITIONS WILL PREVAIL TODAY INTO
TUESDAY. HIGH PRESSURE WILL REMAIN OVER THE EASTERN GREAT LAKES
DURING THIS PERIOD. A ESELY FLOW WILL CONTINUE WITH FEW-SCT
STRATOCUMULUS OR CUMULUS CLOUDS OVER ERN WI DUE TO LAKE EFFECT OR
DAYTIME HEATING. OTHERWISE MO CLEAR SKIES ARE EXPECTED.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...SM/DDV
TODAY/TONIGHT AND AVIATION...GEHRING
TUESDAY THROUGH SUNDAY...WOOD
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1120 PM CDT SUN SEP 22 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 209 PM CDT SUN SEP 22 2013
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A POTENT SHORTWAVE TROUGH OVER UTAH AND ARIZONA...WHILE
RIDGING WAS STRENGTHENING DOWNSTREAM FROM TEXAS INTO MINNESOTA. THE
FORECAST AREA LIES ON THE EAST SIDE OF THE RIDGE...FAVORING
SUBSIDENCE...DRY CONDITIONS AND HIGH PRESSURE. 12Z GRB...DVN AND MPX
SOUNDINGS HAD PRECIPITABLE WATER VALUES OF 0.4-0.65 INCHES...
ANYWHERE FROM 50-100 PERCENT OF NORMAL. THE DRY AIR HAS ALLOWED FOR
SUNNY SKIES ACROSS THE AREA. TEMPERATURES VARY GREATLY ACROSS THE
FORECAST AREA...RESULTING FROM 12Z 925MB TEMPS RANGING FROM 4C AT
GRB TO 11C AT MPX AND DVN. READINGS RANGE FROM THE UPPER 50S AT
MEDFORD TO LOW 70S IN FAR WESTERN PORTIONS OF THE FORECAST AREA.
WINDS ARE INCREASING JUST OFF TO THE WEST OVER THE PLAINS AND
MINNESOTA...AHEAD OF LEE TROUGHING. WARMER AIR IS ACCOMPANYING THE
STRONGER WINDS WITH 925MB TEMPS AT 12Z OF 16C AT ABR AND 20C AT OAX.
SYNOPTIC OVERVIEW...
THE POTENT SHORTWAVE TROUGH IN THE SOUTHWESTERN U.S. IS PROGGED TO
LIFT UP INTO SOUTH DAKOTA AND NEBRASKA BY 00Z TUESDAY. THE APPROACH
OF THE TROUGH WILL HELP STRENGTHEN AND AMPLIFY THE RIDGE AS IT
PUSHES EAST INTO MICHIGAN BY 00Z.
DETAILS...
DRY CONDITIONS ARE GOING TO CONTINUE DESPITE AN INCREASE OF
SOUTHERLY WINDS OVER THE NEXT 24 HOURS. IN FACT...THERE ARE
INDICATIONS THAT PRECIPITABLE WATER VALUES WILL EVEN FALL AS DRY AIR
CENTERED OVER THE OZARKS AREA GETS ADVECTED NORTH ON THE SOUTH
WINDS. THE INCREASING PRESSURE GRADIENT AND SOUTH WINDS OVER THE
AREA TONIGHT WILL LIMIT BOTH TEMPERATURE FALL AND VALLEY FOG
POTENTIAL TONIGHT. COLDEST READINGS ARE EXPECTED TOWARDS CENTRAL
WISCONSIN WHERE GRADIENT IS LIGHTEST...WITH LOWS IN THE UPPER 30S.
MAYBE SOME VALLEY FOG CAN FORM IN THE WISCONSIN RIVER VALLEY BECAUSE
OF THE WIND BEING ORTHAGONAL TO THE VALLEY. COMBINATION OF DRIER
AIR...925MB TEMPS RANGING FROM 12C EAST TO 15C WEST AT 18Z
MONDAY...AND SOUTHERLY BREEZE SHOULD ALLOW TEMPERATURES TO CLIMB
INTO THE UPPER 60S TO LOW 70S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 209 PM CDT SUN SEP 22 2013
FIRST ITEM OF INTEREST IS THE SHORTWAVE TROUGH OVER SOUTH DAKOTA AND
NEBRASKA ON MONDAY. MODELS ARE IN GOOD AGREEMENT OF THE TROUGH
WEAKENING AS IT GETS LIFTED TOWARDS THE FORECAST AREA ON
TUESDAY...IN RESPONSE TO RUNNING INTO THE RIDGING AHEAD OF IT. WITH
THE TROUGH WEAKENING...THE 850MB MOISTURE TRANSPORT ACCOMPANYING IT
ALSO BEGINS TO FALL APART. HOW QUICK THE WEAKENING OF THE TROUGH AND
ASSOCIATED 850MB MOISTURE TRANSPORT OCCURS WILL DETERMINE WHETHER
ANY PRECIPITATION GETS INTO THE FORECAST AREA. THE 22.12Z GFS
CONTINUES TO SUGGEST THE TROUGH WILL STILL BE STRONG ENOUGH TO BRING
SOME SHOWERS TUESDAY AFTERNOON AND EVENING TO LOCATIONS WEST OF THE
MS RIVER. MEANWHILE THE 22.12Z NAM/CANADIAN/UKMET AND 22.00Z/12Z
ECMWF ARE ALL DRY DUE TO THEM WEAKENING THE TROUGH AND MOISTURE
TRANSPORT QUICKER. MODEL CONSENSUS WOULD POINT TO A DRY
FORECAST...BUT HONORED THE GFS AND PREVIOUS FORECAST WITH 20 PERCENT
CHANCES WEST OF THE MS RIVER FOR TUESDAY AFTERNOON.
ANOTHER UPPER RIDGE IS FORECAST TO COME IN BEHIND THE TUESDAY TROUGH
BECAUSE OF A VERY DEEP TROUGH PROGGED TO FORM OVER THE WESTERN U.S.
ON WEDNESDAY. 500MB STANDARDIZED ANOMALIES OVER NEVADA AND
CALIFORNIA AT 00Z THU ARE 3 BELOW NORMAL. HEADING THROUGH THURSDAY
AND FRIDAY...THE TROUGH BEGINS TO LIFT OUT INTO THE NORTHERN
PLAINS...MOST LIKELY IN A POSITIVE TILT...CAUSING A HIGHLY AMPLIFIED
RIDGE TO DEVELOP OVER THE WESTERN GREAT LAKES REGION. SUBSIDENCE
WITH THIS RIDGE WILL KEEP THE FORECAST AREA DRY WEDNESDAY THROUGH
FRIDAY. EXPECT INCREASING SOUTHERLY WINDS AHEAD OF THE TROUGH TO
BRING WARMER AIR TO THE AREA AS WELL...WITH 925MB TEMPS PROGGED TO
CLIMB TO 14-17C ON WEDNESDAY AND THURSDAY...THEN TO 16-19C ON
FRIDAY. DPVA FORCING WITH THE TROUGH SHOULD APPROACH THE AREA FRIDAY
NIGHT...ALONG WITH A SURFACE COLD FRONT. ALL INDICATIONS ARE THAT
THE SOUTHERN PORTION OF THE TROUGH AND COLD FRONT WILL PASS THROUGH
THE FORECAST AREA EITHER SATURDAY OR SATURDAY NIGHT. ONCE THE TROUGH
AXIS PASSES...THE PRECIPITATION WILL END. PLAN ON A COOLER SATURDAY
DUE TO THE COMBINATION OF THE FRONTAL PASSAGE AND PRECIPITATION.
FOR SUNDAY AND EVEN HEADING INTO NEXT WEEK...GOOD MODEL CONTINUITY
EXISTS OF RIDGING STRENGTHENING ACROSS THE WESTERN U.S. AND INTO
SOUTHWEST CANADA. THIS WILL EVENTUALLY SET UP SOME TROUGHING
DOWNSTREAM OVER THE GREAT LAKES REGION. THE 22.12Z ECMWF IS VERY
QUICK AT DEVELOPING THIS TROUGHING...PHASING THE SOUTHERN PORTION OF
THE TROUGH ON SATURDAY WITH TROUGHING TRYING TO SET UP OVER THE
GREAT LAKES REGION. THE RESULT IS A WOUND UP LOW NEAR CHICAGO AT 12Z
SUNDAY. DO NOT HAVE MUCH CONFIDENCE OF THIS OCCURRING...BEING A
PHASING SCENARIO...THUS HAVE WENT WITH THE IDEA OF DRYING COMING IN
BEHIND THE SOUTHERN PORTION OF THE TROUGH. TEMPERATURES LOOK TO BE
JUST SLIGHTLY COOLER ON SUNDAY AS 925MB TEMPS FALL TO 10-13C.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1120 PM CDT SUN SEP 22 2013
AS RIDGE RETREATS TO THE EAST...BROAD SOUTHEAST LOW LEVEL FLOW WILL
CONTINUE THROUGH MONDAY. VFR CONDITIONS WILL PREVAIL IN THIS QUIET
REGIME.
EVEN AS SHORT WAVE TROUGH MOVES OUT OF THE ROCKIES...DRY AIRMASS
WILL LIMIT CLOUDS UNTIL WAVE IS MUCH CLOSER. SYSTEM ALSO PROGGED TO
WEAKEN AS IT GETS CLOSER WHICH COULD ALSO LIMIT IMPACT GOING INTO
TUESDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...SHEA
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1237 AM CDT WED SEP 25 2013
.DISCUSSION...
246 PM CDT
PRIMARY FORECAST CHALLENGE REMAINS THE DECAYING UPPER LOW MOVING
ACROSS THE AREA LATER TONIGHT INTO WEDNESDAY MORNING AND
TIMING/IMPACTS OF WEEKEND SYSTEM.
SHORT TERM (TONIGHT THROUGH FRIDAY)...
CLOSED UPPER LOW OVER IOWA CONTINUES WEAKEN AS IT PUSHES EASTWARD
INTO THE RATHER HIGH AMPLITUDE UPPER RIDGE OVER THE GREAT LAKES AND
OHIO VALLEY. INTERESTINGLY...THE PAST COUPLE RUNS OF THE ECMWF TAKE
THIS SYSTEM OFF THE EAST COAST LATER THIS WEEK AND SHOW IT EVOLVING
INTO A SUB-TROPICAL OR TROPICAL STORM OFF THE EAST COAST BY EARLY
NEXT WEEK! MAIN EFFECTS OF THIS SYSTEM AS IT BRUSHES BY OUR AREA
LATER TONIGHT INTO EARLY WEDNESDAY WILL BE AN INCREASE IN MID-HIGH
LEVEL CLOUDINESS...ESPECIALLY SOUTHERN CWA WHERE A FEW SPRINKLES
FROM THE MID LEVEL DECK CANNOT BE RULED OUT. AS THIS SYSTEM MOVES
EAST LATER WEDNESDAY THE STAGE WILL BE SET FOR SEVERAL DAYS OF
SUNSHINE AND A SLOW WARMING TREND. WARMING TEMPS THROUGH FRIDAY BUT
WITH SOME DEGREE OF AN EASTERLY COMPONENT TO THE SYNOPTIC FLOW
EXPECT TEMPS OVER NE IL (ESPECIALLY RIGHT ALONG THE LAKE) TO REMAIN
A BIT COOLER.
IZZI
LONG TERM (FRIDAY NIGHT THROUGH TUESDAY)...
THOUGH SOME GUIDANCE...NAMELY THE GFS AND ITS ENSEMBLES AND THE
CANADIAN...HAVE TRENDED FASTER WITH FROPA LATE SATURDAY INTO
SUNDAY...FEEL THAT THE STRENGTH OF THE HIGH AMPLITUDE UPPER RIDGE
AHEAD OF FRONT WILL RESULT IN SLOWER PROGRESSION SIMILAR TO 00Z
ECMWF. THERMAL RIDGE WILL BE SQUARELY OVERHEAD ON SAT/850 MB TEMPS
MID TEENS AND 925 MB TEMPS NEARING 20C/AND FORECAST SOUNDINGS
SUGGESTING MINIMAL CLOUD COVER AND MIXING UP TO 850 MB. THUS HAVE
RAISED TEMPS ABOVE GUIDANCE BLEND AND A BIT ABOVE PREVIOUS FORECAST
TO LOW/MID 80S.
FASTER GUIDANCE DOES SUGGEST FRONTAL PRECIP INTO WESTERN CWA BY
SATURDAY EVENING...BUT MAINTAINED SLOWER IDEA FROM PREVIOUS FCST
WITH HIGHEST POPS AFTER MIDNIGHT AND CHANCE POPS INTO
SUNDAY...DIMINISHING FROM THE WEST IN THE AFTERNOON. MINIMAL
MOISTURE RETURN AND RESULT MEAGER INSTABILITY (AT BEST) WILL
PRECLUDE MUCH OF A THREAT FOR THUNDER...BUT DUE TO SHARPNESS OF
UPPER TROUGH DIGGING IN WITH FRONT...IT SEEMS REASONABLE TO KEEP A
SLIGHT CHANCE OF THUNDER IN THE GRIDS. THE EVOLUTION OF CLOSED
UPPER LOW OVER IOWA TODAY THAT COULD SPUR HYBRID TROPICAL
DEVELOPMENT OFF THE EAST COAST OVER THE WEEKEND WILL LIKELY PLAY A
ROLE IN SPEED OF PROGRESSION OF SURFACE AND UPPER FEATURES.
THEN BEHIND THE FRONT EARLY NEXT WORK WEEK...AIRMASS WILL BE OF
PACIFIC ORIGIN...RESULTING IN HIGHS SLIGHTLY ABOVE NORMAL ON MONDAY
AND THEN STRONG HEIGHT RISES OVER CENTRAL CONUS ON TUESDAY COULD
YIELD TEMPS WELL ABOVE NORMAL UPPER 60S/LOW 70S. HAVE GONE ABOVE
STRAIGHT GUIDANCE BLEND TO LOW-MID 70S MON AND SOLIDLY MID 70S
TUESDAY CLOSER TO WARMER GUIDANCE BASED ON UPPER AIR CLIMO. HOWEVER
A PEAK AT 12Z ECMWF SUGGESTS MONDAY COULD BE WARMER THAN TUESDAY
THANKS TO COLD FRONT AND FAIRLY SHARP UPPER TROUGH DIVING IN FROM
NORTHWEST ON TUESDAY.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* NONE. CMS
//DISCUSSION...UPDATED 06Z...
HIGH PRESSURE OVER THE LAKES REGION WILL VERY SLOWLY DRIFT EAST
TONIGHT INTO THURSDAY. WINDS EARLY THIS MORNING WILL REMAIN LIGHT
AND GENERALLY NORTHEASTERLY BUT MAY VARY EASTERLY AT TIMES AND
THEN TURN NORTHEAST THIS MORNING WITH SPEEDS INCREASING TO 10 KTS
WITH THE POTENTIAL FOR SOME HIGHER GUSTS. SPEEDS THEN DIMINISH
THIS EVENING. SCATTERED MID/HIGH CLOUDS WILL CONTINUE INTO THIS
EVENING. THERE IS A POTENTIAL FOR SOME LIGHT/SHALLOW FOG TOWARD
SUNRISE...MAINLY IN THE USUAL LOCATIONS WITH ANOTHER CHANCE OF
LIGHT FOG EARLY THURSDAY MORNING. CMS
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM FOR WIND SPEEDS/DIRECTIONS THROUGH THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
* THURSDAY THROUGH SATURDAY...DRY/VFR.
* SATURDAY NIGHT AND SUNDAY...CHANCE OF SHRA/TSRA.
* MONDAY...DRY/VFR.
KJB
&&
.MARINE...
305 PM...A LARGE AREA OF HIGH PRESSURE CENTERED OVER THE EASTERN
GREAT LAKES WILL REMAIN NEARLY STATIONARY THROUGH FRIDAY AND THEN
SHIFT EAST OVER NEW ENGLAND ON SATURDAY. MEANWHILE...WEAK LOW
PRESSURE OVER MISSOURI WILL TRACK EAST INTO THE TENNESSEE VALLEY
WEDNESDAY AND THEN DISSIPATE BY THURSDAY. A STRONGER IS EXPECTED
TO DEVELOP OVER THE NORTHERN PLAINS WEDNESDAY NIGHT AND THEN LIFT
NORTH INTO MANITOBA ON FRIDAY. ANOTHER LOW IS EXPECTED TO MOVE
OUT OF THE CENTRAL ROCKIES AND INTO THE CENTRAL PLAINS ON THURSDAY
NIGHT AND FRIDAY. THIS LOW WILL THEN ELONGATE AND MERGE WITH THE
SYSTEM THAT LIFTED INTO MANITOBA...WITH A TROUGH OF LOW PRESSURE
AND AN ASSOCIATED COLD FRONT EXTENDING SOUTHWEST INTO EASTERN
COLORADO. THIS SYSTEM WILL SLOWLY TRACK ACROSS THE PLAINS FRIDAY
AND SATURDAY...WITH THE COLD FRONT FINALLY PUSHING ACROSS LAKE
MICHIGAN SATURDAY NIGHT OR SUNDAY.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
1154 PM CDT Tue Sep 24 2013
.DISCUSSION...
ISSUED 859 PM CDT Tue Sep 24 2013
Showers and isolated thunderstorms have developed to the south and
southwest of the area and will be moving north into the region
this evening. HRRR model has a fairly good handle on this and
identifies where the strongest area will be. HRRR pushes the pcpn
into the area south of a Jacksonville to Paris line through 06z
and then weakens the pcpn after midnight. So will be updating the
pops/wx in the forecast for this evening, reflecting closer to
what the new HRRR model run shows. Clouds will remain partly to
mostly cloudy as well. Remainder of the forecast looks fine. So,
updated forecast for pops/wx will be forthcoming shortly.
Auten
&&
.AVIATION...
ISSUED 1154 PM CDT Tue Sep 24 2013
VFR conditions will continue at all sites next 24hrs. Clouds are
scattered to broken across the area with mostly mid and high
clouds present. Some lower clouds at 5kft are there but those
clouds seem to be dissipating as the pcpn dissipates in southwest
IL. Pcpn is not getting as far north as thought adn with clouds
warming believe only VCSH is all that is warranted at SPI and DEC
for a few hours. So will have mid clouds at all sites and
scattered clouds around 6kft at SPI and DEC with VCSH for few
hours. Then mostly sct-bkn mid clouds will be seen at all sites
remainder of the day and into the evening. Winds will be east and
then become northeast during the day and then back east tomorrow evening.
Auten
&&
.PREV DISCUSSION...
ISSUED 243 PM CDT Tue Sep 24 2013
Mostly quiet weather for the forecast with a couple of exceptions.
The first one is the weak low pressure system in northern MO this
afternoon and the associated series of upper waves. Several small
disturbances rotating through the 500mb trof resulting in a
continuation of pops through the overnight hours for the southern
half of Illinois. Quiet and slowly warming temperatures through
the first half of the weekend until the next weather maker moves
through the Midwest late Saturday/Sunday with a return of showers
and thunderstorms for the region. For the most part, models in
good agreement...however, frontal passage over the weekend is a
bit more problematic in regards to timing in previous runs. 12z
runs have better continuity and dry out the Midwest again for the
start of next week.
SHORT TERM...Tonight and tomorrow...
Upper low moving through the region tonight and tomorrow morning,
becoming more of an open wave tomorrow as the surface low dives to
the southeast and weakens. Sat imagery this afternoon showing
several distinct disturbances in the broader trof. In combination
with enough moisture to the southeast to sustain some sct showers
and thunder this morning...will keep the low chance pops in the
south/southeast through the overnight hours. Slight chance pops in
the south for tomorrow will remain in place for the
slowing/opening of the upper trof and general diffuse potential
for any mesoscale triggers. Widespread showers not anticipated
with this system. Overnight lows tonight a little warmer with
expected cloud cover, especially in the southeast. Guidance for
tomorrow night a little more spread with some variability in
residual moisture/clouds in the region with the more open wave.
LONG TERM...Thursday through Monday...
Slowly moderating temperatures through the end of the week...with
midlevel temps climbing from 10C to closer to 15-16C as the
thermal ridge to the west shifts eastward across the country. Dry
weather anticipated until the next cold front late Saturday.
Though timing has been a bit conflicted over the last few runs,
the 12z models are far more together with the timing...but a
little less so with the location of the main sfc low. ECMWF
further south, which would likely impact strength of dynamics for
the storms to pull from. GFS further north with the best energy
and leaving a narrow and quick progression through the region.
ECMWF also magnifying a low in the Atlantic which may or may not
impact timing of the exit of the front in the next few runs. For
now, precip confined to Sat night through Sun night with best
chances Sat night/Sunday. Cooler start to the next work week behind
the front.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
323 AM EDT WED SEP 25 2013
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 330 PM EDT TUE SEP 24 2013
AN UPPER LEVEL LOW ACCOMPANIED BY A SURFACE LOW WILL MOVE THROUGH
THE OHIO VALLEY LATE TONIGHT AND WEDNESDAY BRINGING LOW CHANCES FOR
LIGHT RAIN SHOWERS ACROSS THE SOUTHERN HALF OF OUR REGION.
HIGH PRESSURE AND DRY WEATHER WILL BE THE RULE FROM LATE WEDNESDAY
THROUGH SATURDAY. A COLD FRONT WILL BRINGS A GOOD CHANCE FOR RAIN
SHOWERS AROUND SUNDAY FOLLOWED BY DRY WEATHER MONDAY AND TUESDAY.
TEMPERATURES WILL BECOME QUITE WARM FRIDAY AND SATURDAY AND A LITTLE
COOLER EARLY NEXT WEEK.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 1006 PM EDT TUE SEP 24 2013
PRECIP HAS STRUGGLED TO MAKE EASTWARD PROGRESSION THIS
EVENING...AND THUNDERSTORMS HAVE BEEN CONFINED TO AN AREA NEAR ST
LOUIS AND ANOTHER AREA ALONG THE TN/KY BORDER. HAVE ADJUSTED POPS
OVERNIGHT IN LINE WITH THESE TRENDS AND HRRR GUIDANCE. STILL
MAINLY FOCUSING SHOWER CHANCES ON THE SOUTH/SOUTHWEST. TEMPS LOOK
TO BE IN GOOD SHAPE AND DID NOT REQUIRE ADJUSTMENT.
PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 330 PM EDT TUE SEP 24 2013
AN UPPER LOW CENTERED NEAR KANSAS CITY WILL MOVE TO THE SOUTHERN
PART OF OUR REGION LATE TONIGHT. MODELS INDICATE A FAIR AMOUNT OF
FORCING MAINLY LATE TONIGHT. SOME MOISTURE HAS WORKED INTO THE
LOWER OHIO VALLEY WHILE CENTRAL AND NORTHERN PORTIONS OF OUR REGION
ARE STILL VERY DRY. NAM HAS BEEN SOMEWHAT OVERLY AGGRESSIVE IN
PUSHING MOISTURE INTO OUR REGION AND MOST ENSEMBLES INDICATE LATE OR
NO PRECIPITATION. WILL MENTION LOW CHANCES OF SHOWERS ACROSS THE
SOUTHWEST THIS EVENING AND MOST OF THE SOUTH LATE TONIGHT.
WILL KEEP ALL AREAS DRY ALONG AND NORTH OF A ROCKVILLE TO
INDIANAPOLIS AND RUSHVILLE LINE. CONCERNING TEMPERATURES...A MOS
BLEND SEEMS REASONABLE.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ISSUED AT 330 PM EDT TUE SEP 24 2013
FOCUS IS ON CHANCES FOR RAIN CHANCES WEDNESDAY. A FEW SHOWERS MAY
LINGER ACROSS THE SOUTH HALF OF OUR REGION UNTIL MID AFTERNOON
WEDNESDAY. FORCING IS WEEK...SO WILL GO MORE THAN A 20 PERCENT
CHANCE OF LIGHT SHOWERS OVER THE SOUTHERN 2-3 ROW OF COUNTIES.
THE UPPER LOW WILL MOVE ON TO THE EAST AND MODELS BUILD AN UPPER
RIDGE OF HIGH PRESSURE INTO THE MISSISSIPPI VALLEY THURSDAY AND
ACROSS OUR REGION FRIDAY. EXPECT MOSTLY CLEAR SKIES AND WARMER
DAYTIME TEMPERATURES...ESPECIALLY FRIDAY. WENT CLOSE A MOS BLEND ON
TEMPERATES...EXCEPT A TAD LOWER AT INDY ON THURSDAY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 323 AM EDT WED SEP 25 2013
OHIO VALLEY WILL REMAIN UNDER THE INFLUENCE OF RIDGING ALOFT AND
A BROAD SURFACE HIGH PRESSURE RIDGE TO START THE WEEKEND...WITH
WARM DRY WEATHER FOR SATURDAY. EXTENDED MODEL GUIDANCE HAS
GENERALLY SPED UP ARRIVAL OF A COLD FRONT AND ASSOCIATED RAIN FROM
PREVIOUS RUNS...WITH RAINFALL LIKELY TO REACH WESTERN COUNTIES
LATE SATURDAY NIGHT. STILL PREFER THE SLIGHTLY SLOWER FRONTAL
PASSAGE FAVORED BY THE GLOBAL MODELS. THE ECMWF AND GGEM CONTINUE
TO ADVERTISE A STRONGER LOW PRESSURE SYSTEM IN THE WESTERN
ATLANTIC WHICH COULD SERVE TO DELAY PASSAGE OF THE FRONT THROUGH
THE OHIO VALLEY UNTIL LATER ON SUNDAY. WILL CONTINUE WITH LIKELY
POPS SUNDAY AS A DEEP YET NARROW MOISTURE PLUME ACCOMPANIES THE
BOUNDARY. INSTABILITY REMAINS LIMITED WITH THE FRONT AND WILL
CONTINUE WITH ONLY AN ISOLATED THUNDER MENTION.
HIGH PRESSURE WILL BUILD INTO THE REGION SUNDAY NIGHT WITH DRY
SEASONABLE CONDITIONS FOR EARLY NEXT WEEK AS A QUASI ZONAL FLOW
PATTERN ALOFT ESTABLISHES. ECMWF AND OP GFS BOTH HINT AT A DRY
FRONT PASSING THROUGH THE REGION TUESDAY NIGHT/WEDNESDAY...BUT
LIKELY NO APPRECIABLE CHANGE IN TEMPS EITHER SIDE OF THE BOUNDARY
WITH COLDER AIR BOTTLED UP TO THE NORTH.
AFTER HIGHS IN THE UPPER 70S/LOWER 80S FOR SATURDAY...HIGHS WILL
FALL BACK INTO THE 70S FOR THE DURATION OF THE PERIOD. LOWS AROUND
60 SATURDAY NIGHT AHEAD OF THE MAIN COLD FRONT WILL FALL BACK TO
NEAR SEASONAL NORMALS FOR THE FIRST HALF OF NEXT WEEK.
&&
.AVIATION /DISCUSSION FOR THE 25/0600Z TAF ISSUANCE/...
ISSUED AT 1250 AM EDT WED SEP 25 2013
COULD SEE SOME MVFR FOG AT HUF AND BMG AFTER 09Z. WOULD ALSO NOT
RULE OUT SOME SPOTTY SHOWERS...BUT CONFIDENCE IS TOO LOW FOR
ANYTHING OTHER THAN VCSH. OTHERWISE...EXPECT VFR CONDITIONS WITH
CLEARING AFTER 23Z AS UPPER LOW PRESSURE SYSTEM MOVES EAST OF
CENTRAL INDIANA.
WINDS WILL BE EAST AND NORTHEAST LESS THAN 8 KNOTS THROUGH THE
PERIOD.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH/NIELD
SHORT TERM...JH
LONG TERM....RYAN
AVIATION...MK
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1250 AM EDT WED SEP 25 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 330 PM EDT TUE SEP 24 2013
AN UPPER LEVEL LOW ACCOMPANIED BY A SURFACE LOW WILL MOVE THROUGH
THE OHIO VALLEY LATE TONIGHT AND WEDNESDAY BRINGING LOW CHANCES FOR
LIGHT RAIN SHOWERS ACROSS THE SOUTHERN HALF OF OUR REGION.
HIGH PRESSURE AND DRY WEATHER WILL BE THE RULE FROM LATE WEDNESDAY
THROUGH SATURDAY. A COLD FRONT WILL BRINGS A GOOD CHANCE FOR RAIN
SHOWERS AROUND SUNDAY FOLLOWED BY DRY WEATHER MONDAY AND TUESDAY.
TEMPERATURES WILL BECOME QUITE WARM FRIDAY AND SATURDAY AND A LITTLE
COOLER EARLY NEXT WEEK.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 1006 PM EDT TUE SEP 24 2013
PRECIP HAS STRUGGLED TO MAKE EASTWARD PROGRESSION THIS
EVENING...AND THUNDERSTORMS HAVE BEEN CONFINED TO AN AREA NEAR ST
LOUIS AND ANOTHER AREA ALONG THE TN/KY BORDER. HAVE ADJUSTED POPS
OVERNIGHT IN LINE WITH THESE TRENDS AND HRRR GUIDANCE. STILL
MAINLY FOCUSING SHOWER CHANCES ON THE SOUTH/SOUTHWEST. TEMPS LOOK
TO BE IN GOOD SHAPE AND DID NOT REQUIRE ADJUSTMENT.
PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 330 PM EDT TUE SEP 24 2013
AN UPPER LOW CENTERED NEAR KANSAS CITY WILL MOVE TO THE SOUTHERN
PART OF OUR REGION LATE TONIGHT. MODELS INDICATE A FAIR AMOUNT OF
FORCING MAINLY LATE TONIGHT. SOME MOISTURE HAS WORKED INTO THE
LOWER OHIO VALLEY WHILE CENTRAL AND NORTHERN PORTIONS OF OUR REGION
ARE STILL VERY DRY. NAM HAS BEEN SOMEWHAT OVERLY AGGRESSIVE IN
PUSHING MOISTURE INTO OUR REGION AND MOST ENSEMBLES INDICATE LATE OR
NO PRECIPITATION. WILL MENTION LOW CHANCES OF SHOWERS ACROSS THE
SOUTHWEST THIS EVENING AND MOST OF THE SOUTH LATE TONIGHT.
WILL KEEP ALL AREAS DRY ALONG AND NORTH OF A ROCKVILLE TO
INDIANAPOLIS AND RUSHVILLE LINE. CONCERNING TEMPERATURES...A MOS
BLEND SEEMS REASONABLE.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ISSUED AT 330 PM EDT TUE SEP 24 2013
FOCUS IS ON CHANCES FOR RAIN CHANCES WEDNESDAY. A FEW SHOWERS MAY
LINGER ACROSS THE SOUTH HALF OF OUR REGION UNTIL MID AFTERNOON
WEDNESDAY. FORCING IS WEEK...SO WILL GO MORE THAN A 20 PERCENT
CHANCE OF LIGHT SHOWERS OVER THE SOUTHERN 2-3 ROW OF COUNTIES.
THE UPPER LOW WILL MOVE ON TO THE EAST AND MODELS BUILD AN UPPER
RIDGE OF HIGH PRESSURE INTO THE MISSISSIPPI VALLEY THURSDAY AND
ACROSS OUR REGION FRIDAY. EXPECT MOSTLY CLEAR SKIES AND WARMER
DAYTIME TEMPERATURES...ESPECIALLY FRIDAY. WENT CLOSE A MOS BLEND ON
TEMPERATES...EXCEPT A TAD LOWER AT INDY ON THURSDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ISSUED AT 330 PM EDT TUE SEP 24 2013
THE BEGINNING OF THE EXTENDED PERIOD WILL START OUT DRY WITH RIDGING
OVER THE FORECAST AREA. HOWEVER...FOCUS QUICKLY TURNS TO AN
APPROACHING COLD FRONT EXTENDING FROM ONTARIO TO THE SOUTHERN U.S.
MODELS ARE INDICATING A NARROW BUT WELL-DEFINED PLUME OF MOISTURE
ALONG THE ENTIRE LENGTH OF THAT FRONT. LATEST INITIALIZATION SEEMS
TO BE FAVORING THE SLIGHTLY FASTER GFS OVER THE EURO...WHICH BRINGS
PRECIP INTO WESTERN PORTIONS OF FORECAST AREA BY SATURDAY NIGHT.
INITIALIZATION WAS ALSO TRENDING TOWARD LIKELY POPS FOR SUNDAY... SO
DECIDED TO BE AGGRESSIVE WITH POPS DUE TO SUFFICIENT LIFT ALONG AND
AHEAD OF FRONT. TEMPS WILL CLIMB BACK INTO THE LOW 80S ON
SATURDAY...BUT WILL QUICKLY PLUMMET CLOSER TO NORMAL IN WAKE OF THE
AFOREMENTIONED COLD FRONT.
&&
.AVIATION /DISCUSSION FOR THE 25/0600Z TAF ISSUANCE/...
ISSUED AT 1250 AM EDT WED SEP 25 2013
COULD SEE SOME MVFR FOG AT HUF AND BMG AFTER 09Z. WOULD ALSO NOT
RULE OUT SOME SPOTTY SHOWERS...BUT CONFIDENCE IS TOO LOW FOR
ANYTHING OTHER THAN VCSH. OTHERWISE...EXPECT VFR CONDITIONS WITH
CLEARING AFTER 23Z AS UPPER LOW PRESSURE SYSTEM MOVES EAST OF
CENTRAL INDIANA.
WINDS WILL BE EAST AND NORTHEAST LESS THAN 8 KNOTS THROUGH THE
PERIOD.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH/NIELD
SHORT TERM...JH
LONG TERM....TDUD
AVIATION...MK
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1141 PM CDT Tue Sep 24 2013
.SHORT TERM...(This Evening through Wednesday Night)
Issued at 231 PM CDT TUE SEP 24 2013
Relatively tranquil weather will prevail through much of the next 36
hours, with the one potential exception this afternoon.
As of early this afternoon, a surface low pressure center in the
process of occluding was analyzed near Kansas City, moving
east-southeastward. The shortwave trough aloft was nearly vertically
stacked, with the H85-H5 within 150 miles of the occluding surface
low. Visible satellite imagery has shown a gradual increase in
low-level cumulus, with clearing persistent ahead of the surface
low. A narrow corridor of weak instability has begun to develop
within a southeast to northwest arc. Short-term model guidance has
shown a forecast increase in 0-3km CAPE of up to 200-400J/Kg by
late afternoon over northeast portions of the EAX forecast area.
While the forecast instability is modest at best, this in
combination with strong vertical ascent may promote low-topped
convection to develop by mid to late afternoon. The RUC, NAM, GFS,
GEM, and HRRR outputs all suggest convection to develop in
northeastern sections of the CWA. With an environment characterized
by sufficient instability to maintain low-topped convection,
concomitant with moderate low-level (sfc-H85) directional wind shear
and moderate surface vorticity, the potential exists for a transient
funnel cloud or two underneath persistent updraft bases later this
afternoon in any mature convection that develops. The probability
for this to occur is relatively low, and any chance a vortex would
reach the surface is very low. Overall coverage of lightning
occurrence should be low as well due to the low-topped nature
anticipated with the convection. Much of this forecasted activity is
expected to wane shortly after sunset with the loss of diurnal
instability.
Otherwise, as the shortwave trough shifts east of the area tonight,
an upper ridge will build into the central CONUS on Wednesday. A
notable increase in high temperatures is expected tomorrow afternoon
with highs reaching the upper 70s to lower 80s under mostly clear
skies.
.LONG TERM...(Thursday through Tuesday)
Issued at 231 PM CDT TUE SEP 24 2013
For the later periods of the forecast, lovely late summer/early fall
conditions will dominate, though some thunderstorms might put a
damper on the beginning of the weekend. As Thursday dawns, an
amplified pattern will be in place across the nation, with a large
western CONUS trough juxtaposed against building eastern CONUS
ridge. This will leave our section of the country under rather
benign regime for Thursday and Friday. Models advertise 850mb
temperatures in the mid-teens late in the work week, leaving
expectations that highs will range in the 80s. These above
seasonally average temperatures late in the work week will be
occurring ahead of a frontal passage expected to occur Saturday.
Over the weekend the western CONUS trough will be filling and
lifting through the Plains States. The resulting frontal passage is
currently advertised to occur in our section of Kansas and Missouri
during the daylight hours of Saturday. Models are in decent
agreement on the evolution of the trough and timing of the
associated frontal passage, though given the jet streak noted diving
under the trough as it lifts out thoughts are that the eventual
timing will slow, leaving the frontal passage through our forecast
area lingering into the overnight hours of Saturday. Expectations
are that convection along the front will start Friday night across
areas from central Kansas into eastern Nebraska. These storms will
likely spread into eastern Kansas and far western Missouri towards
sunrise Saturday morning. Slow progress of the front might keep
storms percolating across western Missouri through much of the day,
while also slowly spreading east with the front. Have kept fairly
expansive likely POPs in place for Saturday night owing to low
confidence that the front will have completely cleared the forecast
area before nightfall.
Otherwise, beyond Saturday`s potential stormy weather, the remainder
of the weekend and into next work week (Sunday through Tuesday)
looks rather beautiful. Temperatures are currently expected to range
between highs in the 70s and lows in the 50s as a quasi-zonal upper
level pattern moves into the Plains in the wake of the exiting
trough.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday Night)
Issued at 1139 PM CDT TUE SEP 24 2013
The primary concern overnight will be the development of mainly
ground fog over most of the region. While MVFR visibilities will be the
rule am expecting pockets of dense fog with visibilities of a 1/4sm
or less to form during the pre-dawn hours, especially in river
valleys and low-lying areas. Local effects due to air temperatures
cooling below the surrounding water temperature at KSTJ also warrant
inclusion of dense fog. All of the fog will burn off quickly by mid-
morning.
Otherwise, VFR conditions expected with pockets of mid clouds across
northern MO overnight but most of the earlier cloud cover has
dissipated and will not return.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...Blair
LONG TERM...Cutter
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1245 AM CDT WED SEP 25 2013
.UPDATE...
ISSUED AT 1244 AM CDT WED SEP 25 2013
MAIN FORECAST CHANGE/ADDITION THROUGH THE REST OF THE OVERNIGHT
HOURS IS A GENERIC MENTION OF PATCHY FOG ACROSS PRIMARILY THE
NORTHEAST 1/2 OF THE CWA. ALTHOUGH STILL NOT OVERLY CONCERNED
ABOUT WIDESPREAD VISIBILITY ISSUES...ITS HARD TO IGNORE THAT THE
LEAST HRRR IS INSISTING THAT POTENTIALLY DENSE FOG COULD BLOSSOM
MAINLY IN MAINLY EAST/NORTHEAST AREAS AS THE NIGHT WEARS ON. PROS
FOR FOG FORMATION OBVIOUSLY INCLUDE FAIRLY LOW SURFACE
TEMP/DEWPOINT SPREADS AND VERY LIGHT TO NEAR CALM BREEZES...BUT ON
THE FLIP SIDE FLOW IN THE BOUNDARY LAYER PER THE 00Z NAM WOULD
SEEM TO BE STRONG ENOUGH TO PRECLUDE SIGNIFICANT/IMPACTFUL FOG AS
THE SURFACE RIDGE AXIS SLIDES TO THE EAST. ALL THINGS
CONSIDERED...FELT IT BEST TO GET SOME EARLY MORNING PATCHY FOG
WORDING IN THE FORECAST JUST IN CASE...AND WILL EVALUATE AS THE
NIGHT WEARS ON WHETHER THIS MIGHT NEED BEEFED UP...OR CONVERSELY
REMOVED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 350 PM CDT CDT TUE SEP 24 2013
HIGH PRESSURE WILL TRANSITION ACROSS THE PLAINS OVERNIGHT AS A BROAD
AREA OF LOW PRESSURE MOVES INLAND ACROSS THE WEST COAST. WITH THE
LOCAL AREA LYING BETWEEN TWO SYSTEMS...EXPECT WINDS TO DIMINISH
SIGNIFICANTLY AFTER SUNSET...SKIES TO CLEAR...AND FOR TEMPERATURES
TO FALL TO NEAR OR JUST BELOW NORMAL BY EARLY WEDNESDAY MORNING.
WENT AHEAD AND CONTINUED WITH TEMPERATURES A DEGREE OR TWO BELOW
GUIDANCE AT MOST LOCATIONS TO REFLECT THIS THINKING.
OTHERWISE...WITH CLEARING SKIES AND LIGHT WINDS EXPECTED
OVERNIGHT...SOME OF THE MODELS ARE INDICATING THERE MAY BE SOME VERY
PATCHY FOG FORMATION FOR THE EARLY MORNING HOURS WEDNESDAY.
HOWEVER WITH DEWPOINTS ALREADY IN THE LOW TO MID 50S AND EXPECTED
TO FALL SOME TONIGHT...AS WELL AS LIGHT WINDS EXPECTED TO PROMOTE
JUST ENOUGH MIXING TO PREVENT ANY FOG FORMATION...DECIDED NOT TO
INCLUDE MENTION IN THE LATEST FORECAST...WITH THINKING BEING IF
ANY PATCHY FOG IS ABLE TO DEVELOP IT WILL BE VERY THIN AND BURN
OFF JUST AFTER SUNRISE.
OTHERWISE A NICE...ALBEIT BREEZY DAY IS EXPECTED ACROSS THE REGION
TOMORROW AS THE PRESSURE GRADIENT BEGINS TO TIGHTEN AS A LEE
TROUGH DEVELOPS TO OUR WEST AHEAD OF THE NEXT DISTURBANCE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 350 PM CDT TUE SEP 24 2013
PRIMARY FORECAST CONCERN THROUGH THE LONG TERM PERIOD LIES WITH LATE
WEEK/EARLY WEEKEND PRECIPITATION CHANCES.
MODELS IN PRETTY GOOD AGREEMENT AT THE START OF THE PERIOD...SHOWING
A GRADUALLY MORE AMPLIFIED UPPER LEVEL PATTERN DEVELOPING ACROSS
MUCH OF THE CONUS. UPPER LEVEL LOW PRESSURE IS EXPECTED TO BE IN
PLACE OVER THE PAC NW...WHICH GRADUALLY SLIDES E/SE THROUGH THE
DAYTIME HOURS ON THURSDAY. THURSDAY STILL LOOKING TO BE DRY...AND
THE WARMEST DAY OF THE LONG TERM PERIOD...WITH ANOTHER ROUND OF
GUSTY SOUTHERLY WINDS THANKS TO THE TIGHTENED SFC PRESSURE
GRADIENT...AND WARMER AIR ALOFT MOVING IN FROM THE WEST. HIGHS
LOOKING TO TOP OUT IN THE LOW/MID 80S IN THE NW TO NEAR 90 IN THE
SE.
THURSDAY NIGHT...THIS LOW PRESSURE SYSTEM CONTINUES TO DIG SOUTH INTO
THE DESERT SW...WHILE RIDGING EXTENDS FROM THE GULF COAST REGION
NORTH TOWARD THE HUDSON BAY AREA. THIS FEATURE WILL BRING THE ONLY
CHANCE FOR PRECIPITATION THROUGH THE ENTIRE FORECAST PERIOD...AND
MAY START TO AFFECT THE CWA ALREADY BY 12Z FRIDAY. SOME UNCERTAINTY
REMAINS IN PLACE WITH THE ONSET OF PRECIPITATION...MAINLY BECAUSE OF
THE CONSISTENT ACTIVITY DEVELOPED BY THE GFS OVERNIGHT /OTHER MODELS
HAVE BACKED OFF OR ARE COMPLETELY DRY PRE-12Z/. WHILE THERE IS GOOD
AGREEMENT AMONG THE MODELS SHOWING AN UPPER LEVEL JET STREAK ARND
100KT ROUNDING THE BASE OF THE TROUGH AND NOSING INTO THE
PLAINS...THE GFS CONTINUES TO BE A TOUCH STRONGER WITH THE FEATURE
AND A LITTLE FURTHER EAST. DID KEEP SOME LOWER POPS IN THE
FORECAST...BUT KEPT THEM CONFINED TO THE 06-12Z TIMEFRAME.
INTO THE DAYTIME HOURS FRIDAY AND FRIDAY NIGHT...THE MAIN CHANGE
WITH THE MODELS WAS TO CONTINUE A SLIGHT SLOWING TREND IN THE
EASTWARD MOVEMENT OF THE PRECIP/SFC FRONT. AT 12Z FRIDAY THERE ARE
STILL EVEN SOME DIFFERENCES BETWEEN MODELS...SOME SAY THE FRONT IS
KNOCKING ON THE DOOR OF THE NW CORNER OF THE CWA...OTHERS /ESP THE
ECMWF/ SHOW THE FRONT STILL OVER THE SANDHILLS. EVEN THROUGH THE
DAYTIME HOURS...THE FRONT DOESNT LOOK TO HAVE MADE A LOT OF EASTWARD
PROGRESS...WITH THE MAIN UPPER LEVEL LOW MOVING NORTHEAST INTO
CENTRAL CANADA...LEAVING A OPEN WAVE BEHIND OVER THE ROCKIES. BY
FRIDAY EVENING...THE FRONT IS CURRENTLY EXPECTED TO STILL BE
AFFECTING PRIMARILY THE NWRN HALF OF THE CWA...AND THATS WHERE THE
HIGHER POPS REMAIN. WITH THE SLOWER TREND TO THE FRONT...DID BUMP
UP HIGHS ON FRIDAY...MAINLY ACROSS THE SERN HALF AS CLOUD COVER
SHOULD BE HIGHER NW...WITH THE FORECAST RANGING FROM THE MID 70S NW
TO MID 80S SE.
THE BEST CHANCES FOR PRECIPITATION FOR THE CWA IS EXPECTED TO COME
FRIDAY NIGHT...AS THE UPPER LEVEL TROUGH FINALLY SWINGS ONTO THE
PLAINS...AND THE SURFACE COLD FRONT MOVES THROUGH THE CWA. DID
INCREASE POPS A TOUCH...WITH LIKELIES EVERYWHERE. BY 12Z SATURDAY
THE LOCATION OF THE FRONT ISNT BAD...MAINLY BECAUSE THE ECMWF SHOWS
A STRONGER PUSH AND CATCHES UP TO THE GFS...BUT BOTH SHOW THE FRONT
OVER FAR ERN PORTIONS OF THE CWA...AND MOVING OFF TO ERN NEB/KS BY
MIDDAY. CONTINUED THE LINGERING POPS POST-12Z...BUT AT THIS POINT
MODELS SHOW THIS WOULD BE MAINLY CONFINED TO THE MORNING HOURS AND
OVER THE ERN THIRD OF THE CWA. THE AFTERNOON SHOULD BE DRY...WITH
MORE SUNSHINE WORKING IN...A DRIER AND COOLER AIR MASS BRINGING
HIGHS IN THE MID 60S TO MID 70S.
KEPT THE MENTION OF THUNDER GOING THROUGH FRIDAY NIGHT...WITH JUST
SHOWERS SATURDAY...THERE ISNT NOTABLE INSTABILITY AT ANY POINT...BUT
MODELS AGREE WITH WHATEVER THERE IS BEING EAST OF THE CWA BY 12Z
SATURDAY.
FOR SUNDAY THROUGH TUESDAY...NO SIGNIFICANT CHANGES WERE MADE TO THE
FORECAST...WHICH REMAINS DRY AS MODELS SHOW A FAIRLY ZONAL
PATTERN...BUT NO NOTABLE DISTURBANCES EXPECTED TO MOVE THROUGH.
HIGHS EXPECTED TO GENERALLY RANGE FROM THE MID 70S TO LOWER 80S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1134 PM CDT TUE SEP 24 2013
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. MENTIONED A PERIOD OF LIGHT
FOG AROUND SUNRISE DUE TO GOOD RADIATIONAL COOLING CONDITIONS. EXPECT
THE FOG TO BE AT THE HIGH END OF MVFR (AROUND 5 MILES) FROM
09-14Z. THE ONLY OTHER THING WORTH MENTIONING IS GUSTY SOUTH WINDS
THAT WILL BE REVVING UP AFTER 14Z DUE TO A TIGHT PRESSURE GRADIENT
AND CONTINUE THROUGH THE DAYLIGHT HOURS. EXPECT FREQUENT GUSTS
OVER 24 KTS.
&&
.HYDROLOGY...
ISSUED AT 340 PM CDT TUE SEP 24 2013
OVERALL THERE HAS BEEN LITTLE CHANGE IN THE EXPECTATIONS
REGARDING THE PLATTE RIVER FLOODING/FLOODING POTENTIAL. AS OF 3 PM
CST...WE CONTINUE TO ADVERTISE TWO OFFICIAL FLOOD WARNINGS...ONE
FOR THE RIVER GAGE NEAR COZAD...WHICH COVERS THE PLATTE RIVER
REACH ACROSS DAWSON COUNTY INTO FAR WESTERN BUFFALO...AND A SECOND
FOR THE GAGE NEAR KEARNEY...WHICH COVERS THE REACH OF THE RIVER
ALONG THE BUFFALO/PHELPS/KEARNEY COUNTY LINE...AND THEN ACROSS THE
MAJORITY OF HALL COUNTY. THE LATEST MISSOURI BASIN RIVER FORECAST
CENTER (MBRFC) FORECAST NO LONGER TAKES THE GRAND ISLAND GAGE A
FEW MILES EAST OF TOWN INTO MINOR FLOOD STAGE WEDNESDAY
NIGHT...BUT INSTEAD CRESTS THE RIVER VERY CLOSE TO MINOR FLOOD
STAGE EARLY FRIDAY MORNING...SO WE WILL NEED TO CONTINUE TO
MONITOR THIS AS WE GET A BETTER FEEL FOR THE ACTUAL VOLUME OF
WATER APPROACHING THAT AREA IN CASE ADDITIONAL WARNINGS MAY BECOME
NECESSARY.
EVEN SO...PLEASE NOTE ONLY MINOR FLOOD STAGE...AND NOT
MODERATE/MAJOR CATEGORIES...ARE ANTICIPATED ACROSS THE LOCAL
AREA...AND THUS THE VAST MAJORITY OF IMPACTS SHOULD REMAIN
CONFINED TO THE IMMEDIATE LOWLAND AREAS NEAR THE PLATTE RIVER AND
ITS ASSOCIATED CHANNELS. THESE RIVER FORECASTS ARE UPDATED
REGULARLY PER COORDINATION BETWEEN MBRFC AND THE NWS
HASTINGS...AND MINOR TWEAKS IN CREST HEIGHT AND TIMING REMAIN
LIKELY OVER THE COMING DAYS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...SAR
LONG TERM...ADO
AVIATION...EDDY
HYDROLOGY...SAR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
315 AM EDT WED SEP 25 2013
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL APPROACH THE REGION FROM THE
NORTHWEST TODAY... THEN SLOWLY CROSS THE AREA LATE TODAY THROUGH
TONIGHT AND THURSDAY. HIGH PRESSURE WILL BUILD IN FROM THE NORTH
FRIDAY THROUGH SATURDAY.
&&
.NEAR TERM /TODAY THROUGH TONIGHT/...
AS OF 240 AM WEDNESDAY...
THROUGH TODAY: DRY WEATHER THROUGH MUCH OF TODAY WILL GIVE WAY TO
PATCHY LIGHT RAIN OVER THE WRN CWA TOWARD NIGHTFALL. A WEAKENING
OCCLUSION CURRENTLY SITS OVER THE LOWER MISS VALLEY WITH A FRONT
EXTENDING EASTWARD TO A STRENGTHENING LOW JUST OFF THE GA/FL COAST.
ONE WEAK MID LEVEL WAVE AND ATTENDING BATCH OF CIRRUS HAS DEPARTED
TO OUR NE... AND WE`RE NOW IN A RELATIVELY CLEAR AREA AHEAD OF MORE
BROKEN HIGH CLOUDS SLOWLY SPREADING EASTWARD TOWARD NC FROM THE
WEST... ASSOCIATED WITH WEAK DPVA AHEAD OF THE INCOMING MID LEVEL
VORTEX NOW OVER SRN IL. STRONGER POCKETS OF VORTICITY ARE DUE TO
SWEEP EAST INTO THE AREA AS THE VORTEX CROSSES THE OH VALLEY
APPROACHING VA/NC LATE. DYNAMIC FORCING FOR ASCENT BASED ABOVE 700
MB WILL SPREAD IN FROM THE WEST THROUGH THE AFTERNOON... WITH THE
PRIMARY MECHANISMS CONSISTING OF DPVA AND STRENGTHENING UPPER
DIVERGENCE ASSOCIATED WITH A STRENGTHENING JETLET FROM THE NW OVER
SRN IL INTO KY/TN. THIS WILL RESULT IN A THICKENING AND LOWERING OF
MID CLOUDS THROUGH THE DAY... ESPECIALLY IN THE WRN CWA... WHILE IN
THE EAST... DRY AIR ADVECTION IN THE LOW LEVELS (EVIDENT AT 925-850
MB) ON THE LIGHT NE FLOW WILL KEEP THE COLUMN RELATIVELY DRY BELOW
700 MB. IN SHORT... EXPECT A TREND TO MOSTLY CLOUDY OR CLOUDY SKIES
FROM WEST TO EAST. EXPECT ANY LIGHT RAIN IN THE WRN PIEDMONT TO HOLD
OFF UNTIL AFTER 4 PM WITH THE LOW LEVELS REMAINING FAIRLY DRY
THROUGH THAT TIME... ALTHOUGH PATCHY LIGHT SPRINKLES MAY OCCUR IN
THE LATE AFTERNOON. WITH LOW LEVEL THICKNESSES EXPECTED TO WARM UP
TO 1380-1385 M LATER TODAY... AND A DECENT AMOUNT OF FILTERED
SUNSHINE FROM MID MORNING (AFTER ANY MORNING FOG/STRATUS BURNS OFF)
THROUGH EARLY/MID AFTERNOON... HAVE NUDGED UP HIGH TEMPS TO 73-78.
FOR TONIGHT: THE NAM/GFS ARE MUCH WETTER WITH THEIR MOST RECENT
COUPLE OF RUNS THAN THEY WERE LAST NIGHT... SHOWING SOME MOISTENING
TAKING PLACE BELOW 700 MB... ENOUGH TO SUPPORT MEASURABLE PRECIP
DESPITE INDICATIONS THAT MOST LIFT WILL REMAIN ROOTED AT AND ABOVE
700 MB WITH NO LOWER LEVEL FORCING MECHANISMS EVIDENT. BOTH UPPER
DIVERGENCE WITH THE DIVING JETLET AND MID LEVEL DPVA MAXIMIZE
OVERNIGHT... AS DOES PRECIP WATER... WHOSE VALUES TOP OUT NEAR 1.6
INCHES OVER THE WRN PIEDMONT BEFORE SLIPPING BACK TOWARD 1.25 INCHES
IN THE SOUTHERN CWA LATE. THE MID LEVEL LOW SHIFTS OVER THE REGION
TO BE CENTERED OVER SOUTH CENTRAL VA BY THU MORNING... BUT THE PATH
OF THE 850 MB LOW IS FARTHER SOUTH... FROM TN SE ACROSS SC...
KEEPING THE LOW LEVEL FLOW COMING FROM A DRIER NE OR NORTHERLY
DIRECTION. SO... WHATEVER LOW LEVEL MOISTENING TAKES PLACE WILL
LIKELY COME FROM WHAT FALLS IN FROM ABOVE... RATHER THAN FROM ANY
HORIZONTAL MOISTURE ADVECTION... AND THIS SHOULD SERVE TO KEEP QPF
ON THE LOW SIDE THROUGH THIS EVENT FOR MUCH OF CENTRAL NC (WITH THE
TRIAD REGION SEEING HIGHER TOTALS GIVEN THE UPSLOPE CONTRIBUTION TO
LIFT AND THE CLOSER PROXIMITY TO THE 850 MB LOW TRACK). WILL SPREAD
GOOD CHANCE POPS INTO THE WRN CWA VERY EARLY EVENING WITH SLIGHT
CHANCE (CENTRAL) TO NO POPS (FAR EAST) IN THE EVENING... THEN EXPECT
CHANCE POPS AREAWIDE FROM MIDNIGHT ONWARD. AMOUNTS SHOULD RANGE FROM
A QUARTER TO THIRD INCH IN THE TRIAD AND FAR SW CWA TO JUST A FEW
HUNDREDTHS IN THE NE CWA. WILL STICK WITH LOWS IN THE UPPER 50S TO
NEAR 60... CLOSE TO STATISTICAL GUIDANCE. -GIH
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 315 AM WEDNESDAY...
THE 850 MB LOW MOVES FROM E TN TO THE SE ALONG THE 850 MB FRONTAL
ZONE BEFORE WEAKENING THEN DISSIPATING OVER UPSTATE SC... IN FAVOR
OF THE STRENGTHENING 850 MB LOW OFF THE COAST. THE RESULTING
RESUMPTION OF NORTHEASTERLY LOW LEVEL FLOW WILL PULL DRIER AIR INTO
THE NORTH CENTRAL CWA... AND WILL END POPS HERE IN THE MORNING. BUT
THE SLIGHTLY MORE EASTERLY FLOW SHOULD BRING A PERIOD OF MOIST
UPGLIDE IN OUR FAR WRN CWA IN THE MORNING... SO WILL RETAIN A SLIGHT
CHANCE OF LIGHT RAIN HERE EARLY. AND THE MID LEVEL DPVA SHOULD STILL
BE AFFECTING THE EASTERN/SRN CWA EARLY IN THE DAY UNTIL IT MOVES TO
OUR EAST... SO WILL HOLD ONTO A SLIGHT CHANCE IN THE COASTAL PLAIN
AS WELL. CONSIDERABLE DRYING TAKES PLACE THROUGH THE COLUMN BY
15Z-18Z THURSDAY WITH WEAK SUBSIDENCE BEHIND THE EXITING VORTEX AND
A NORTHEASTERLY FLOW BELOW 700 MB. THIS FLOW MAY STILL DRAW SOME
ATLANTIC MOISTURE INTO THE AREA FROM THE NORTHEAST THROUGH THE
DAY... SO WE MAY NOT SEE SKIES BECOME TOTALLY CLEAR... ESPECIALLY IN
THE SE CWA... BUT WE`LL AT LEAST SEE PARTIAL SUNSHINE OVER MOST OF
THE CWA AND AN END TO RAIN CHANCES EVERYWHERE BY EARLY AFTERNOON.
EXPECT SKIES TO BE MOSTLY CLEAR OVERNIGHT... WITH THE EXCEPTION OF A
FEW MID CLOUDS AS A WEAK PERTURBATION ROTATES DOWN THE WEST SIDE OF
THE DEPARTING VORTEX. HIGHS IN THE MID 70S AND LOWS IN THE LOW-MID
50S. -GIH
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 230 AM WEDNESDAY.
AN EXTENDED DRY PERIOD TYPICAL OF FALL EXPECTED...
AN ALREADY AMPLIFIED LONGWAVE PATTERN WILL UNDERGO FURTHER
AMPLIFICATION OVER THE WEEKEND AS AN UPPER TROUGH OVER THE WESTERN
ATLANTIC CLOSES OFF AND THE RIDGE UPSTREAM OF THE MOUNTAINS
SHARPENS. BETWEEN THESE FEATURES...A COOL NORTHEASTERLY WIND WILL
PREVAIL THROUGH THE WEEKEND...WITH THICKNESSES PROGGED TO BE 15-20M
BELOW NORMAL SATURDAY AND SUNDAY MORNING. THIS WOULD CORRESPOND TO
HIGHS IN THE LOW TO MID 70S. REGARDING THE UPPER LOW OFFSHORE...THE
ECMWF HAS BEEN CONSISTENTLY THE DEEPER OF THE MEDIUM RANGE
MODELS...ALTHOUGH ITS STRENGTH APPEARS TO BE IN PART A RESULT OF THE
INTERJECTION OF ADDITIONAL SHORTWAVE ENERGY MOVING SOUTH OUT OF
CANADA ON THE BACKSIDE OF THE TROUGH AXIS...WHICH IS A DETAIL THAT
IS HARD TO PUT FAITH IN THIS FAR OUT. THE STRONGER SCENARIO WOULD
BRING THE UPPER LOW AND ASSOCIATED SURFACE LOW FURTHER WEST AND
CLOSER TO THE EASTERN SEABOARD...LEADING TO BETTER MOISTURE
ADVECTION INTO EASTERN NC FROM THE NORTHEAST. WPC PREFERS THE ECMWF
TRACK OF THE SURFACE LOW...BUT ALSO QUESTIONS THE STRENGTH.
THUS...WILL CONTINUE TO KEEP ALL OF THE CWA DRY SUNDAY AND SUNDAY
NIGHT AS THE LOW PASSES BY.
BY MONDAY...THE SURFACE LOW WILL LIFT OFF TO THE NORTHEAST AND A
COLD FRONT WILL BEGIN TO APPROACH FROM THE NORTHEAST.
HOWEVER...MOISTURE WILL BE SCARCE BY THE TIME IT MOVES INTO THE
REGION...AND IT APPEARS IT WILL BE TOUGH TO GET MUCH PRECIP EAST OF
THE MOUNTAINS. TEMPS SHOULD REBOUND BACK TO AROUND NORMAL EARLY
NEXT WEEK...WITH A TRANSITION TO A MORE ZONAL FLOW ALOFT EXPECTED.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 1255 AM WEDNESDAY...
ADVERSE AVIATION CONDITIONS APPEAR LIKELY THROUGH ABOUT 12Z... AS
THE COMBINATION OF JUST A FEW HIGH THIN CLOUDS... LIGHT TO CALM
WINDS... AND INCREASING SURFACE RH TO PROMOTE FOG AND STRATUS
DEVELOPMENT. STATISTICAL GUIDANCE AND THE RECENT HRRR MODEL RUNS
SUPPORT A TREND TOWARD IFR CONDITIONS AT ALL SITES... PEAKING AT
08Z-12Z... THEN MIXING OUT WITH HEATING TO VFR BETWEEN 12Z AND 14Z.
AS SURFACE LOW PRESSURE SLIDES TO OUR SOUTH AND AN UPPER LEVEL
DISTURBANCE APPROACHES FROM THE NW... CLOUDS WILL INCREASE AND
THICKEN OVER CENTRAL NC THROUGH THE DAY WITH CLOUDS BASED AROUND
5000 FT AGL AND ANOTHER DECK AROUND 8000-12000 FT AGL SPREADING IN
FROM THE WEST. AFTER 00Z... CIGS ARE EXPECTED TO LOWER FURTHER
THROUGH 06Z... STAYING VFR AT RDU/RWI/FAY BUT LIKELY TO DROP TO MVFR
AT INT/GSO AFTER 03Z WITH PATCHES OF LIGHT RAIN POSSIBLE. SURFACE
WINDS WILL BE MOSTLY FROM THE NE UNDER 8 KTS THROUGH 06Z EARLY
THURSDAY MORNING.
LOOKING BEYOND 06Z EARLY THURSDAY MORNING... MVFR-IFR CONDITIONS ARE
EXPECTED AT GSO/INT WITH MVFR CONDITIONS POSSIBLE AT RDU/RWI/FAY
AFTER 06Z THROUGH THURSDAY MORNING. THEN AS THE SYSTEM EXITS THE
REGION... VFR CONDITIONS SHOULD RETURN THURSDAY AFTERNOON... LASTING
THROUGH SUNDAY AS NARROW HIGH PRESSURE NOSES IN FROM THE NORTH...
ALTHOUGH A PERIOD OF IFR FOG IS POSSIBLE 08Z-13Z EACH MORNING FRIDAY
THROUGH SUNDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...SMITH
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
245 AM EDT WED SEP 25 2013
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL APPROACH THE REGION FROM THE
NORTHWEST TODAY... THEN SLOWLY CROSS THE AREA LATE TODAY THROUGH
TONIGHT AND THURSDAY. HIGH PRESSURE WILL BUILD IN FROM THE NORTH
FRIDAY THROUGH SATURDAY.
&&
.NEAR TERM /TODAY THROUGH TONIGHT/...
AS OF 240 AM WEDNESDAY...
THROUGH TODAY: DRY WEATHER THROUGH MUCH OF TODAY WILL GIVE WAY TO
PATCHY LIGHT RAIN OVER THE WRN CWA TOWARD NIGHTFALL. A WEAKENING
OCCLUSION CURRENTLY SITS OVER THE LOWER MISS VALLEY WITH A FRONT
EXTENDING EASTWARD TO A STRENGTHENING LOW JUST OFF THE GA/FL COAST.
ONE WEAK MID LEVEL WAVE AND ATTENDING BATCH OF CIRRUS HAS DEPARTED
TO OUR NE... AND WE`RE NOW IN A RELATIVELY CLEAR AREA AHEAD OF MORE
BROKEN HIGH CLOUDS SLOWLY SPREADING EASTWARD TOWARD NC FROM THE
WEST... ASSOCIATED WITH WEAK DPVA AHEAD OF THE INCOMING MID LEVEL
VORTEX NOW OVER SRN IL. STRONGER POCKETS OF VORTICITY ARE DUE TO
SWEEP EAST INTO THE AREA AS THE VORTEX CROSSES THE OH VALLEY
APPROACHING VA/NC LATE. DYNAMIC FORCING FOR ASCENT BASED ABOVE 700
MB WILL SPREAD IN FROM THE WEST THROUGH THE AFTERNOON... WITH THE
PRIMARY MECHANISMS CONSISTING OF DPVA AND STRENGTHENING UPPER
DIVERGENCE ASSOCIATED WITH A STRENGTHENING JETLET FROM THE NW OVER
SRN IL INTO KY/TN. THIS WILL RESULT IN A THICKENING AND LOWERING OF
MID CLOUDS THROUGH THE DAY... ESPECIALLY IN THE WRN CWA... WHILE IN
THE EAST... DRY AIR ADVECTION IN THE LOW LEVELS (EVIDENT AT 925-850
MB) ON THE LIGHT NE FLOW WILL KEEP THE COLUMN RELATIVELY DRY BELOW
700 MB. IN SHORT... EXPECT A TREND TO MOSTLY CLOUDY OR CLOUDY SKIES
FROM WEST TO EAST. EXPECT ANY LIGHT RAIN IN THE WRN PIEDMONT TO HOLD
OFF UNTIL AFTER 4 PM WITH THE LOW LEVELS REMAINING FAIRLY DRY
THROUGH THAT TIME... ALTHOUGH PATCHY LIGHT SPRINKLES MAY OCCUR IN
THE LATE AFTERNOON. WITH LOW LEVEL THICKNESSES EXPECTED TO WARM UP
TO 1380-1385 M LATER TODAY... AND A DECENT AMOUNT OF FILTERED
SUNSHINE FROM MID MORNING (AFTER ANY MORNING FOG/STRATUS BURNS OFF)
THROUGH EARLY/MID AFTERNOON... HAVE NUDGED UP HIGH TEMPS TO 73-78.
FOR TONIGHT: THE NAM/GFS ARE MUCH WETTER WITH THEIR MOST RECENT
COUPLE OF RUNS THAN THEY WERE LAST NIGHT... SHOWING SOME MOISTENING
TAKING PLACE BELOW 700 MB... ENOUGH TO SUPPORT MEASURABLE PRECIP
DESPITE INDICATIONS THAT MOST LIFT WILL REMAIN ROOTED AT AND ABOVE
700 MB WITH NO LOWER LEVEL FORCING MECHANISMS EVIDENT. BOTH UPPER
DIVERGENCE WITH THE DIVING JETLET AND MID LEVEL DPVA MAXIMIZE
OVERNIGHT... AS DOES PRECIP WATER... WHOSE VALUES TOP OUT NEAR 1.6
INCHES OVER THE WRN PIEDMONT BEFORE SLIPPING BACK TOWARD 1.25 INCHES
IN THE SOUTHERN CWA LATE. THE MID LEVEL LOW SHIFTS OVER THE REGION
TO BE CENTERED OVER SOUTH CENTRAL VA BY THU MORNING... BUT THE PATH
OF THE 850 MB LOW IS FARTHER SOUTH... FROM TN SE ACROSS SC...
KEEPING THE LOW LEVEL FLOW COMING FROM A DRIER NE OR NORTHERLY
DIRECTION. SO... WHATEVER LOW LEVEL MOISTENING TAKES PLACE WILL
LIKELY COME FROM WHAT FALLS IN FROM ABOVE... RATHER THAN FROM ANY
HORIZONTAL MOISTURE ADVECTION... AND THIS SHOULD SERVE TO KEEP QPF
ON THE LOW SIDE THROUGH THIS EVENT FOR MUCH OF CENTRAL NC (WITH THE
TRIAD REGION SEEING HIGHER TOTALS GIVEN THE UPSLOPE CONTRIBUTION TO
LIFT AND THE CLOSER PROXIMITY TO THE 850 MB LOW TRACK). WILL SPREAD
GOOD CHANCE POPS INTO THE WRN CWA VERY EARLY EVENING WITH SLIGHT
CHANCE (CENTRAL) TO NO POPS (FAR EAST) IN THE EVENING... THEN EXPECT
CHANCE POPS AREAWIDE FROM MIDNIGHT ONWARD. AMOUNTS SHOULD RANGE FROM
A QUARTER TO THIRD INCH IN THE TRIAD AND FAR SW CWA TO JUST A FEW
HUNDREDTHS IN THE NE CWA. WILL STICK WITH LOWS IN THE UPPER 50S TO
NEAR 60... CLOSE TO STATISTICAL GUIDANCE. -GIH
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 245 PM TUESDAY...
SUBSIDENCE ON THE BACK SIDE OF THE DEPARTING MID/UPPER TROUGH IS
STILL SLATED TO REACH OUR REGION THURSDAY. MODELS ARE IN FAIRLY GOOD
AGREEMENT IN DEPICTING THE PASSAGE OF THE UPPER LEVEL SW-NE ORIENTED
TROUGH AXIS THROUGH THE NW IN THE MORNING... SLIDING OFF TO THE SE
BY THURSDAY EVENING. AT THE SAME TIME... SURFACE HIGH PRESSURE IS
EXPECTED TO BUILD/EXPAND DOWN THE EASTERN SEABOARD FROM NEW ENGLAND.
AFTER A FEW SPRINKLES AROUND 12Z OR SO THURSDAY... MOISTURE WILL
RAPIDLY DECREASE WITH CLEARING SKIES FROM THE NW AS THE TROUGH AXIS
SHIFTS THROUGH THURSDAY AND THURSDAY EVENING. HIGHS THURSDAY SHOULD
BE IN THE 75-80 RANGE. LOWS GENERALLY 50-55 WITH SOME UPPER 40S IN
THE PIEDMONT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 230 AM WEDNESDAY.
AN EXTENDED DRY PERIOD TYPICAL OF FALL EXPECTED...
AN ALREADY AMPLIFIED LONGWAVE PATTERN WILL UNDERGO FURTHER
AMPLIFICATION OVER THE WEEKEND AS AN UPPER TROUGH OVER THE WESTERN
ATLANTIC CLOSES OFF AND THE RIDGE UPSTREAM OF THE MOUNTAINS
SHARPENS. BETWEEN THESE FEATURES...A COOL NORTHEASTERLY WIND WILL
PREVAIL THROUGH THE WEEKEND...WITH THICKNESSES PROGGED TO BE 15-20M
BELOW NORMAL SATURDAY AND SUNDAY MORNING. THIS WOULD CORRESPOND TO
HIGHS IN THE LOW TO MID 70S. REGARDING THE UPPER LOW OFFSHORE...THE
ECMWF HAS BEEN CONSISTENTLY THE DEEPER OF THE MEDIUM RANGE
MODELS...ALTHOUGH ITS STRENGTH APPEARS TO BE IN PART A RESULT OF THE
INTERJECTION OF ADDITIONAL SHORTWAVE ENERGY MOVING SOUTH OUT OF
CANADA ON THE BACKSIDE OF THE TROUGH AXIS...WHICH IS A DETAIL THAT
IS HARD TO PUT FAITH IN THIS FAR OUT. THE STRONGER SCENARIO WOULD
BRING THE UPPER LOW AND ASSOCIATED SURFACE LOW FURTHER WEST AND
CLOSER TO THE EASTERN SEABOARD...LEADING TO BETTER MOISTURE
ADVECTION INTO EASTERN NC FROM THE NORTHEAST. WPC PREFERS THE ECMWF
TRACK OF THE SURFACE LOW...BUT ALSO QUESTIONS THE STRENGTH.
THUS...WILL CONTINUE TO KEEP ALL OF THE CWA DRY SUNDAY AND SUNDAY
NIGHT AS THE LOW PASSES BY.
BY MONDAY...THE SURFACE LOW WILL LIFT OFF TO THE NORTHEAST AND A
COLD FRONT WILL BEGIN TO APPROACH FROM THE NORTHEAST.
HOWEVER...MOISTURE WILL BE SCARCE BY THE TIME IT MOVES INTO THE
REGION...AND IT APPEARS IT WILL BE TOUGH TO GET MUCH PRECIP EAST OF
THE MOUNTAINS. TEMPS SHOULD REBOUND BACK TO AROUND NORMAL EARLY
NEXT WEEK...WITH A TRANSITION TO A MORE ZONAL FLOW ALOFT EXPECTED.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 1255 AM WEDNESDAY...
ADVERSE AVIATION CONDITIONS APPEAR LIKELY THROUGH ABOUT 12Z... AS
THE COMBINATION OF JUST A FEW HIGH THIN CLOUDS... LIGHT TO CALM
WINDS... AND INCREASING SURFACE RH TO PROMOTE FOG AND STRATUS
DEVELOPMENT. STATISTICAL GUIDANCE AND THE RECENT HRRR MODEL RUNS
SUPPORT A TREND TOWARD IFR CONDITIONS AT ALL SITES... PEAKING AT
08Z-12Z... THEN MIXING OUT WITH HEATING TO VFR BETWEEN 12Z AND 14Z.
AS SURFACE LOW PRESSURE SLIDES TO OUR SOUTH AND AN UPPER LEVEL
DISTURBANCE APPROACHES FROM THE NW... CLOUDS WILL INCREASE AND
THICKEN OVER CENTRAL NC THROUGH THE DAY WITH CLOUDS BASED AROUND
5000 FT AGL AND ANOTHER DECK AROUND 8000-12000 FT AGL SPREADING IN
FROM THE WEST. AFTER 00Z... CIGS ARE EXPECTED TO LOWER FURTHER
THROUGH 06Z... STAYING VFR AT RDU/RWI/FAY BUT LIKELY TO DROP TO MVFR
AT INT/GSO AFTER 03Z WITH PATCHES OF LIGHT RAIN POSSIBLE. SURFACE
WINDS WILL BE MOSTLY FROM THE NE UNDER 8 KTS THROUGH 06Z EARLY
THURSDAY MORNING.
LOOKING BEYOND 06Z EARLY THURSDAY MORNING... MVFR-IFR CONDITIONS ARE
EXPECTED AT GSO/INT WITH MVFR CONDITIONS POSSIBLE AT RDU/RWI/FAY
AFTER 06Z THROUGH THURSDAY MORNING. THEN AS THE SYSTEM EXITS THE
REGION... VFR CONDITIONS SHOULD RETURN THURSDAY AFTERNOON... LASTING
THROUGH SUNDAY AS NARROW HIGH PRESSURE NOSES IN FROM THE NORTH...
ALTHOUGH A PERIOD OF IFR FOG IS POSSIBLE 08Z-13Z EACH MORNING FRIDAY
THROUGH SUNDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...BADGETT
LONG TERM...SMITH
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
230 AM EDT WED SEP 25 2013
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL APPROACH THE REGION FROM THE
NORTHWEST TODAY... THEN SLOWLY CROSS THE AREA LATE TODAY THROUGH
TONIGHT AND THURSDAY. HIGH PRESSURE WILL BUILD IN FROM THE NORTH
FRIDAY THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 PM TUESDAY...
COOL AND DRY CONDITIONS WILL PREVAIL OVERNIGHT AS SURFACE HIGH
PRESSURE PRESIDES OVER EASTERN NORTH CAROLINA WITH RIDGING ALOFT.
INFRARED SATELLITE AND WATER VAPOR IMAGERY SHOW MOISTURE INCREASING
AHEAD OF A DEVELOPING LOW PRESSURE SYSTEM CURRENTLY OVER EASTERN
LOUISIANA WITH AN ASSOCIATED STATIONARY FRONT SET UP ALONG THE
FLORIDA PANHANDLE. CLOSER TO HOME...THE EDGES OF THE CLOUD COVER
ASSOCIATED WITH THESE FEATURES HAS REACHED THE CWA AND SHOULD
CONTINUE TO SPREAD NORTHEASTWARD THROUGHOUT THE COURSE OF THE
OVERNIGHT HOURS THIN AT FIRST BUT GRADUALLY BECOMING MORE DENSE WITH
TIME. WHILE THE TEMPERATURE GRADIENT SHOULD STILL HAVE THE WARMEST
LOWS IN THE SOUTHWEST (MID TO UPPER 50S)...CLOUDS ARE MOVING FAST
ENOUGH THAT THE UPPER 40S FORECAST IN THE EAST MAY END UP BEING
CLOSER TO 50 DEGREES AND HAVE UPDATED THE FORECAST TO ILLUSTRATE
THIS. OTHERWISE THE COOL DRY FORECAST REMAINS INTACT THROUGH THE
REMAINDER OF THE NIGHT.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 245 PM TUESDAY...
THE UPPER LEVEL LOW PROGRESSING INTO THE TN VALLEY TONIGHT WILL
GRADUALLY DEAMPLIFY AS IT TRACKS SLOWLY EAST ACROSS THE CAROLINAS
WED AND WED NIGHT. MID/UPPER LEVEL MOISTURE WILL INCREASE THROUGHOUT
THE DAY IN ADVANCE OF THE WAVE...WITH PWAT VALUES CLIMBING TO
~1.25". ALTHOUGH FORCING FOR ASCENT WILL BE PRESENT IN THE FORM OF
DPVA AS THE WAVE TRACKS INTO THE REGION...LOW-LEVEL FORCING WILL
LARGELY BE ABSENT...WITH WARM ADVECTION CONFINED TO THE DEEP SOUTH
AND SOUTHEAST COAST...AND FOR THIS REASON THE BEST CHANCE FOR PRECIP
WITH THIS SYSTEM WILL LIKELY REMAIN WELL SOUTH AND SOUTHWEST OF
CENTRAL NC. HOWEVER...COOLING TEMPS ALOFT IN THE PRESENCE OF
REASONABLE DEEP LAYER MOISTURE AND DPVA SHOULD STILL SUPPORT A LOW
TO MODERATE CHANCE (20-40%) OF SHOWERS WED INTO WED NIGHT...
PRIMARILY ACROSS THE WESTERN PIEDMONT AND SANDHILLS...IN LINE WITH
THE 12Z GFS/NAM WHICH BOTH SHOW MEASURABLE PRECIPITATION IN THOSE
REGIONS. EXPECT HIGHS ON WED TO BE NO HIGHER THAN TODAY GIVEN A VERY
SIMILAR AIRMASS...MORE LIKELY AT LEAST SEVERAL DEGREES COOLER THAN
TODAY GIVEN INCREASED CLOUD COVER AND A CHANCE FOR RAIN /EVAP
COOLING/. WILL INDICATE HIGHS RANGING FROM 70-75F...COOLEST WEST.
LOWS WED NIGHT IN THE MID/UPPER 50S TO NEAR 60F. -VINCENT
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 230 AM WEDNESDAY.
AN EXTENDED DRY PERIOD TYPICAL OF FALL EXPECTED...
AN ALREADY AMPLIFIED LONGWAVE PATTERN WILL UNDERGO FURTHER
AMPLIFICATION OVER THE WEEKEND AS AN UPPER TROUGH OVER THE WESTERN
ATLANTIC CLOSES OFF AND THE RIDGE UPSTREAM OF THE MOUNTAINS
SHARPENS. BETWEEN THESE FEATURES...A COOL NORTHEASTERLY WIND WILL
PREVAIL THROUGH THE WEEKEND...WITH THICKNESSES PROGGED TO BE 15-20M
BELOW NORMAL SATURDAY AND SUNDAY MORNING. THIS WOULD CORRESPOND TO
HIGHS IN THE LOW TO MID 70S. REGARDING THE UPPER LOW OFFSHORE...THE
ECMWF HAS BEEN CONSISTENTLY THE DEEPER OF THE MEDIUM RANGE
MODELS...ALTHOUGH ITS STRENGTH APPEARS TO BE IN PART A RESULT OF THE
INTERJECTION OF ADDITIONAL SHORTWAVE ENERGY MOVING SOUTH OUT OF
CANADA ON THE BACKSIDE OF THE TROUGH AXIS...WHICH IS A DETAIL THAT
IS HARD TO PUT FAITH IN THIS FAR OUT. THE STRONGER SCENARIO WOULD
BRING THE UPPER LOW AND ASSOCIATED SURFACE LOW FURTHER WEST AND
CLOSER TO THE EASTERN SEABOARD...LEADING TO BETTER MOISTURE
ADVECTION INTO EASTERN NC FROM THE NORTHEAST. WPC PREFERS THE ECMWF
TRACK OF THE SURFACE LOW...BUT ALSO QUESTIONS THE STRENGTH.
THUS...WILL CONTINUE TO KEEP ALL OF THE CWA DRY SUNDAY AND SUNDAY
NIGHT AS THE LOW PASSES BY.
BY MONDAY...THE SURFACE LOW WILL LIFT OFF TO THE NORTHEAST AND A
COLD FRONT WILL BEGIN TO APPROACH FROM THE NORTHEAST.
HOWEVER...MOISTURE WILL BE SCARCE BY THE TIME IT MOVES INTO THE
REGION...AND IT APPEARS IT WILL BE TOUGH TO GET MUCH PRECIP EAST OF
THE MOUNTAINS. TEMPS SHOULD REBOUND BACK TO AROUND NORMAL EARLY
NEXT WEEK...WITH A TRANSITION TO A MORE ZONAL FLOW ALOFT EXPECTED.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 1255 AM WEDNESDAY...
ADVERSE AVIATION CONDITIONS APPEAR LIKELY THROUGH ABOUT 12Z... AS
THE COMBINATION OF JUST A FEW HIGH THIN CLOUDS... LIGHT TO CALM
WINDS... AND INCREASING SURFACE RH TO PROMOTE FOG AND STRATUS
DEVELOPMENT. STATISTICAL GUIDANCE AND THE RECENT HRRR MODEL RUNS
SUPPORT A TREND TOWARD IFR CONDITIONS AT ALL SITES... PEAKING AT
08Z-12Z... THEN MIXING OUT WITH HEATING TO VFR BETWEEN 12Z AND 14Z.
AS SURFACE LOW PRESSURE SLIDES TO OUR SOUTH AND AN UPPER LEVEL
DISTURBANCE APPROACHES FROM THE NW... CLOUDS WILL INCREASE AND
THICKEN OVER CENTRAL NC THROUGH THE DAY WITH CLOUDS BASED AROUND
5000 FT AGL AND ANOTHER DECK AROUND 8000-12000 FT AGL SPREADING IN
FROM THE WEST. AFTER 00Z... CIGS ARE EXPECTED TO LOWER FURTHER
THROUGH 06Z... STAYING VFR AT RDU/RWI/FAY BUT LIKELY TO DROP TO MVFR
AT INT/GSO AFTER 03Z WITH PATCHES OF LIGHT RAIN POSSIBLE. SURFACE
WINDS WILL BE MOSTLY FROM THE NE UNDER 8 KTS THROUGH 06Z EARLY
THURSDAY MORNING.
LOOKING BEYOND 06Z EARLY THURSDAY MORNING... MVFR-IFR CONDITIONS ARE
EXPECTED AT GSO/INT WITH MVFR CONDITIONS POSSIBLE AT RDU/RWI/FAY
AFTER 06Z THROUGH THURSDAY MORNING. THEN AS THE SYSTEM EXITS THE
REGION... VFR CONDITIONS SHOULD RETURN THURSDAY AFTERNOON... LASTING
THROUGH SUNDAY AS NARROW HIGH PRESSURE NOSES IN FROM THE NORTH...
ALTHOUGH A PERIOD OF IFR FOG IS POSSIBLE 08Z-13Z EACH MORNING FRIDAY
THROUGH SUNDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...ELLIS
SHORT TERM...VINCENT
LONG TERM...SMITH
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1258 AM EDT WED SEP 25 2013
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL APPROACH THE REGION FROM THE
NORTHWEST TODAY... THEN SLOWLY CROSS THE AREA LATE TODAY THROUGH
TONIGHT AND THURSDAY. HIGH PRESSURE WILL BUILD IN FROM THE NORTH
FRIDAY THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 PM TUESDAY...
COOL AND DRY CONDITIONS WILL PREVAIL OVERNIGHT AS SURFACE HIGH
PRESSURE PRESIDES OVER EASTERN NORTH CAROLINA WITH RIDGING ALOFT.
INFRARED SATELLITE AND WATER VAPOR IMAGERY SHOW MOISTURE INCREASING
AHEAD OF A DEVELOPING LOW PRESSURE SYSTEM CURRENTLY OVER EASTERN
LOUISIANA WITH AN ASSOCIATED STATIONARY FRONT SET UP ALONG THE
FLORIDA PANHANDLE. CLOSER TO HOME...THE EDGES OF THE CLOUD COVER
ASSOCIATED WITH THESE FEATURES HAS REACHED THE CWA AND SHOULD
CONTINUE TO SPREAD NORTHEASTWARD THROUGHOUT THE COURSE OF THE
OVERNIGHT HOURS THIN AT FIRST BUT GRADUALLY BECOMING MORE DENSE WITH
TIME. WHILE THE TEMPERATURE GRADIENT SHOULD STILL HAVE THE WARMEST
LOWS IN THE SOUTHWEST (MID TO UPPER 50S)...CLOUDS ARE MOVING FAST
ENOUGH THAT THE UPPER 40S FORECAST IN THE EAST MAY END UP BEING
CLOSER TO 50 DEGREES AND HAVE UPDATED THE FORECAST TO ILLUSTRATE
THIS. OTHERWISE THE COOL DRY FORECAST REMAINS INTACT THROUGH THE
REMAINDER OF THE NIGHT.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 245 PM TUESDAY...
THE UPPER LEVEL LOW PROGRESSING INTO THE TN VALLEY TONIGHT WILL
GRADUALLY DEAMPLIFY AS IT TRACKS SLOWLY EAST ACROSS THE CAROLINAS
WED AND WED NIGHT. MID/UPPER LEVEL MOISTURE WILL INCREASE THROUGHOUT
THE DAY IN ADVANCE OF THE WAVE...WITH PWAT VALUES CLIMBING TO
~1.25". ALTHOUGH FORCING FOR ASCENT WILL BE PRESENT IN THE FORM OF
DPVA AS THE WAVE TRACKS INTO THE REGION...LOW-LEVEL FORCING WILL
LARGELY BE ABSENT...WITH WARM ADVECTION CONFINED TO THE DEEP SOUTH
AND SOUTHEAST COAST...AND FOR THIS REASON THE BEST CHANCE FOR PRECIP
WITH THIS SYSTEM WILL LIKELY REMAIN WELL SOUTH AND SOUTHWEST OF
CENTRAL NC. HOWEVER...COOLING TEMPS ALOFT IN THE PRESENCE OF
REASONABLE DEEP LAYER MOISTURE AND DPVA SHOULD STILL SUPPORT A LOW
TO MODERATE CHANCE (20-40%) OF SHOWERS WED INTO WED NIGHT...
PRIMARILY ACROSS THE WESTERN PIEDMONT AND SANDHILLS...IN LINE WITH
THE 12Z GFS/NAM WHICH BOTH SHOW MEASURABLE PRECIPITATION IN THOSE
REGIONS. EXPECT HIGHS ON WED TO BE NO HIGHER THAN TODAY GIVEN A VERY
SIMILAR AIRMASS...MORE LIKELY AT LEAST SEVERAL DEGREES COOLER THAN
TODAY GIVEN INCREASED CLOUD COVER AND A CHANCE FOR RAIN /EVAP
COOLING/. WILL INDICATE HIGHS RANGING FROM 70-75F...COOLEST WEST.
LOWS WED NIGHT IN THE MID/UPPER 50S TO NEAR 60F. -VINCENT
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 155 PM TUESDAY...
AN EXTENDED DRY PERIOD TYPICAL OF FALL EXPECTED...
SUBSIDENCE ON THE BACK SIDE OF THE DEPARTING MID/UPPER TROUGH IS
STILL SLATED TO REACH OUR REGION THURSDAY. MODELS ARE IN FAIRLY GOOD
AGREEMENT IN DEPICTING THE PASSAGE OF THE UPPER LEVEL SW-NE ORIENTED
TROUGH AXIS THROUGH THE NW IN THE MORNING... SLIDING OFF TO THE SE
BY THURSDAY EVENING. AT THE SAME TIME... SURFACE HIGH PRESSURE IS
EXPECTED TO BUILD/EXPAND DOWN THE EASTERN SEABOARD FROM NEW ENGLAND
THURSDAY AFTERNOON THROUGH SATURDAY. COOLER AND MUCH DRIER AIR WILL
SPREAD DEEP INTO NC/SC FRI-SUN.
AFTER A FEW SPRINKLES AROUND 12Z OR SO THURSDAY... MOISTURE WILL
RAPIDLY DECREASE WITH CLEARING SKIES FROM THE NW AS THE TROUGH AXIS
SHIFTS THROUGH THURSDAY AND THURSDAY EVENING. THEN CLEAR/MOSTLY
SUNNY SKIES ARE EXPECTED FRIDAY THROUGH SUNDAY. HIGHS THURSDAY
SHOULD BE IN THE 75-80 RANGE... COOLING INTO THE LOWER TO MID 70S
FRI/SAT/SUN. LOWS GENERALLY 50-55 WITH SOME UPPER 40S IN THE
PIEDMONT.
SUNDAY NIGHT THROUGH TUESDAY... WPC FAVORS A WESTERN ATLANTIC STORM
SYSTEM TO DEVELOP/TRACK WELL EAST OF CAPE HATTERAS LATE SUNDAY INTO
EARLY MONDAY. ANY ASSOCIATED ADVERSE WEATHER IS EXPECTED TO REMAIN
WELL OFFSHORE OF THE NC COAST. A RIDGE OF HIGH PRESSURE IS ALSO
EXPECTED TO REMAIN IN PLACE MON-TUE... BETWEEN THE WESTERN ATLANTIC
SYSTEM TRACKING WELL OFF NEW ENGLAND... AND THE APPROACHING AND
DECAYING NEXT MID/UPPER TROUGH / ASSOCIATED SURFACE FRONT FROM THE
MIDWEST. WE WILL DEPICT SOME INCREASE IN CLOUDINESS BY MON-TUE...
BUT KEEP ANY CHANCE OF SHOWERS OUT AS MOISTURE IS EXPECTED TO BE
LACKING OVER OUR REGION. RIGHT NOW... EXPECT PARTLY CLOUDY SKIES
MONDAY THROUGH TUESDAY. LOWS GENERALLY IN THE 52-57 RANGE AND HIGHS
72-77.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 1255 AM WEDNESDAY...
ADVERSE AVIATION CONDITIONS APPEAR LIKELY THROUGH ABOUT 12Z... AS
THE COMBINATION OF JUST A FEW HIGH THIN CLOUDS... LIGHT TO CALM
WINDS... AND INCREASING SURFACE RH TO PROMOTE FOG AND STRATUS
DEVELOPMENT. STATISTICAL GUIDANCE AND THE RECENT HRRR MODEL RUNS
SUPPORT A TREND TOWARD IFR CONDITIONS AT ALL SITES... PEAKING AT
08Z-12Z... THEN MIXING OUT WITH HEATING TO VFR BETWEEN 12Z AND 14Z.
AS SURFACE LOW PRESSURE SLIDES TO OUR SOUTH AND AN UPPER LEVEL
DISTURBANCE APPROACHES FROM THE NW... CLOUDS WILL INCREASE AND
THICKEN OVER CENTRAL NC THROUGH THE DAY WITH CLOUDS BASED AROUND
5000 FT AGL AND ANOTHER DECK AROUND 8000-12000 FT AGL SPREADING IN
FROM THE WEST. AFTER 00Z... CIGS ARE EXPECTED TO LOWER FURTHER
THROUGH 06Z... STAYING VFR AT RDU/RWI/FAY BUT LIKELY TO DROP TO MVFR
AT INT/GSO AFTER 03Z WITH PATCHES OF LIGHT RAIN POSSIBLE. SURFACE
WINDS WILL BE MOSTLY FROM THE NE UNDER 8 KTS THROUGH 06Z EARLY
THURSDAY MORNING.
LOOKING BEYOND 06Z EARLY THURSDAY MORNING... MVFR-IFR CONDITIONS ARE
EXPECTED AT GSO/INT WITH MVFR CONDITIONS POSSIBLE AT RDU/RWI/FAY
AFTER 06Z THROUGH THURSDAY MORNING. THEN AS THE SYSTEM EXITS THE
REGION... VFR CONDITIONS SHOULD RETURN THURSDAY AFTERNOON... LASTING
THROUGH SUNDAY AS NARROW HIGH PRESSURE NOSES IN FROM THE NORTH...
ALTHOUGH A PERIOD OF IFR FOG IS POSSIBLE 08Z-13Z EACH MORNING FRIDAY
THROUGH SUNDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...ELLIS
SHORT TERM...VINCENT
LONG TERM...BADGETT
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1235 AM CDT WED SEP 25 2013
.UPDATE...
ISSUED AT 1235 AM CDT WED SEP 25 2013
LATEST REGIONAL RADAR SHOWS MOSTLY MID LEVEL MOISTURE RETURNS IN
EASTERN MONTANA MOVING NORTHEAST WITH TIME. THE HRRR AND TO SOME
EXTENT THE GFS AND RAP13 INDICATE A POSSIBLE SHOWER BETWEEN 06Z-
12Z IN THE FAR NORTHWEST TO FAR NORTH CENTRAL. VERY CLOSE CALL AT
THIS TIME AND HAVE DECIDED TO INCLUDE THE AFOREMENTIONED AREA IN
AN ISOLATED SHOWER MENTION THROUGH 12Z. SURFACE MAP SHOWS MAX 3HR
PRESSURE FALLS NEAR TROTTERS EXTENDING SOUTHWEST TO GLENDIVE.
SURFACE LOW PRESSURE IN SOUTHEAST MONTANA WILL BE MOVING TOWARD
THIS AREA OF MAX PRESSURE FALLS OVERNIGHT WHICH MAY RESULT IN A
SPOTTY AREA FOR MEASURABLE PRECIPITATION. REST OF THE FORECAST
REMAINS ON TRACK.
UPDATE ISSUED AT 926 PM CDT TUE SEP 24 2013
LATE EVENING UPDATE MAINLY FOR HOURLY TEMPERATURE TRENDS AND
OVERNIGHT LOWS. LIGHT WINDS AND RELATIVELY DRY AIR HAVE RESULTED
IN A RAPID TEMPERATURE DROP THIS EVENING...ESPECIALLY ACROSS THE
EAST. HAVE MODIFIED THE HOURLY TRENDS TO REFLECT AN EARLIER LOW
BEING REACHED IN THE WEST BEFORE THE WINDS KICK IN AND KEEP TEMPS
STEADY TO SLOWLY RISING...AND A LATER MINIMUM ACROSS THE EAST. THE END
RESULT WAS DROPPING OVERNIGHT LOWS 2 TO 4 DEGREES MOST LOCATIONS.
A FEW LIGHT RADAR RETURNS HAVE MOVED INTO EASTERN MONTANA...BUT
WITH THE ABUNDANT DRY AIR ITS DOUBTFUL ANY RAIN WILL REACH THE GROUND.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 330 PM CDT TUE SEP 24 2013
A LEADING SHORTWAVE AHEAD OF ITS PRIMARY UPPER LEVEL TROUGH OVER
THE PACIFIC NORTHWEST WILL LIFT INTO NORTHEASTERN MONTANA TONIGHT.
ITS SURFACE REFLECTION WILL TIGHTEN THE SURFACE PRESSURE GRADIENT
AND ATTENDANT BOUNDARY LAYER HEIGHT GRADIENTS OVER WESTERN NORTH
DAKOTA TONIGHT. BOTH THE LATEST GFS AND ECMWF PROG SOUTHERLY 850MB
WINDS TO INCREASE TO AROUND 50 KNOTS OVER SOUTHWESTERN NORTH
DAKOTA BY 06Z TONIGHT...THEN TRANSLATE EAST INTO THE AREAS BETWEEN
HIGHWAYS 85 AND 83 BY 12Z TUESDAY. DO NOT THINK MORE THAN HALF OF
THIS MOMENTUM WILL TRANSFER TO THE SURFACE GIVEN THE PROGGED MOIST
ADIABATIC LAPSE RATES IN THE BOUNDARY LAYER. HOWEVER...GIVEN THE
TURBULENT BOUNDARY LAYER FLOW...SIDED WITH THE WARMEST GUIDANCE
FOR OVERNIGHT LOWS.
A SURFACE TROUGH AXIS IS THEN FORECAST TO ENTER WESTERN NORTH
DAKOTA WEDNESDAY. MODELS ARE PAINTING QPF WEST OF THE BOUNDARY
WHERE THE DEEPEST MOISTURE IS PROGGED TO DEVELOP. HOWEVER...THE
GREATEST MUCAPE VALUES (AROUND 300 J/KG) ARE PROGGED TO DEVELOP
ALONG THE BOUNDARY...WHICH IS FORECAST TO EXTEND ALONG A LINE FROM
HETTINGER TO GARRISON TO WESTHOPE. GIVEN THE RELATIVE LACK OF
SURFACE MOISTURE CONVERGENCE...DECIDED TO HOLD OFF ON EXTENDING
POPS EAST TO ALONG THE BOUNDARY WEDNESDAY AFTERNOON.
HOWEVER...WOULD NOT BE SURPRISED TO SEE AN ISOLATED THUNDERSTORM
DEVELOP ALONG THE BOUNDARY LATE IN THE DAY (SAY AROUND 4PM CDT OR
SO). THE BULK OF THE CONVECTIVE ACTIVITY SHOULD INITIATE AFTER 7PM
CDT WEDNESDAY. SEE LONG TERM DISCUSSION BELOW FOR MORE DETAILS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 PM CDT TUE SEP 24 2013
THE HIGHLIGHTS OF THE EXTENDED PERIOD IS RAIN AND WIND WEDNESDAY
THROUGH FRIDAY AND POTENTIAL SEVERE WEATHER WEDNESDAY NIGHT.
AN UPPER LEVEL LONGWAVE TROUGH...CURRENTLY DIGGING INTO WESTERN
OREGON AND WASHINGTON...SHOULD PUSH INTO WESTERN MONTANA BY
WEDNESDAY. AHEAD OF THE TROUGH...QUASI ZONAL FLOW WILL QUICKLY
TRANSITION TO SOUTHWEST FLOW. THIS WILL IN TURN PROMOTE SURFACE LEE
CYCLOGENESIS ACROSS THE EASTERN ROCKY MOUNTAIN RANGE IN WYOMING AND
MONTANA. THIS LEE CYCLOGENESIS IS PROGGED TO DEVELOP INTO A LARGE
INVERTED TROUGH CENTERED ACROSS NORTH DAKOTA AND ENCOMPASS MOST OF
THE NORTHERN PLAINS.
AS A RESULT OF THIS INVERTED TROUGH A STEEP PRESSURE GRADIENT IS
PROGGED TO SETUP ACROSS THE WESTERN DAKOTAS WEDNESDAY MORNING.
FURTHER PRESSURE FALLS AHEAD OF THE SURFACE TROUGH AIDED BY WARM AIR
ADVECTION WILL LIKELY FURTHER ENHANCE THE MAGNITUDE OF PRESSURE DIFFERENCES
FROM MONTANA TO MINNESOTA. THEREFORE WINDY CONDITIONS...35 MPH
GUSTS...ARE POSSIBLE ACROSS MOST OF THE NORTHERN PLAINS WEDNESDAY
THROUGH FRIDAY.
THURSDAY EVENING STRONG TO POTENTIALLY SEVERE STORMS ARE POSSIBLE
ACROSS WEST CENTRAL NORTH DAKOTA. THE 12 UTC NAM AND GFS HAVE STEEP
LOW LEVEL LAPSE RATES AND VERY STRONG SHEAR (50 KNOTS 0-6 KM AND 15
KNOTS 0-1 KM) ACROSS WEST CENTRAL NORTH DAKOTA DURING THE LATE
AFTERNOON AND EVENING HOURS OF WEDNESDAY. HOWEVER...CAPE IS FORECAST
TO BE MARGINAL. BUT...NONETHELESS...THIS WILL HAVE TO BE CLOSELY
MONITORED.
ADDITIONALLY...STRONG LOW LEVEL WARM MOIST AIR RETURN AHEAD OF THE
TROUGH SHOULD PROVIDE AMPLE MOISTURE RETURN TO FUEL WIDESPREAD
SHOWERS AND THUNDERSTORMS. THE 12 UTC NAM/GFS HAVE PWAT VALUES
APPROACHING 1.15 INCHES ACROSS MOST OF THE STATE THURSDAY THROUGH
FRIDAY. THIS PWAT VALUE IS MORE THAN TWO STANDARD DEVIATIONS ABOVE
NORMAL FOR THIS TIME OF YEAR. LOCALLY HEAVY RAINFALL IS POSSIBLE
WEDNESDAY THROUGH FRIDAY.
THE 12 UTC GFS AND ECMWF HAVE THE LONGWAVE TROUGH AND ASSOCIATED
100+ KNOT JET IN A FAVORABLE RAIN PRODUCING POSITION WEST OF NORTH
DAKOTA THROUGH LATE FRIDAY. THEREFORE...OFF AND ON SCATTERED TO
WIDESPREAD PRECIP IS POSSIBLE STARTING WEDNESDAY NIGHT CONTINUING
THROUGH FRIDAY NIGHT. HOWEVER...A DRY PERIOD IS LIKELY THURSDAY
AFTERNOON AND EARLY EVENING. THE 12 UTC ECMWF AND GFS ARE BOTH
PROGGING A SUBSTANTIAL DRY SLOT TO WRAP INTO WESTERN NORTH DAKOTA
THURSDAY AFTERNOON. THIS WILL SHUT OFF PRECIP AT LEAST UNTIL THE
EVENING HOURS WHEN ANOTHER SHORTWAVE IS PROGGED TO ROTATE AROUND THE
MAIN UPPER LEVEL TROUGH. THE MOST LIKELY AREA FOR THE HEAVIEST AND
PROLONGED PRECIPITATION APPEARS TO BE ACROSS NORTHWESTERN AND NORTH
CENTRAL NORTH DAKOTA. THIS IS THE AREA WHERE THE 12 UTC
GFS/ECMWF/NAM HAVE THE BEST UPPER LEVEL JET DYNAMICS INTERACTING
WITH STRONG ISENTROPIC AND ISALLOBARIC FORCING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1235 AM CDT WED SEP 25 2013
FOR THE WESTERN AERORDEOMS...KISN/KDIK SCT TO BKN MID/HIGH LEVEL
CLOUDS WILL DOMINATE THE TAF PERIOD. BEST CHANCES FOR
PRECIPITATION NOT UNTIL 00Z THURSDAY AND BEYOND. THE CENTRAL
TERMINALS OF KMOT/KBIS/KJMS WILL MAINLY SEE SCT MID/HIGH CLOUDS
AND BECOME BKN AFTER 00Z THURSDAY. LOW LEVEL WIND SHEAR A FAIRLY
HIGH PROBABILITY GIVEN THE WARM AIR ADVECTION PATTERN AT ALL
TERMINALS EXCEPT KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...TM
LONG TERM...AJ
AVIATION...KS
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1115 PM CDT TUE SEP 24 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 256 CDT TUE SEP 24 2013
MINIMAL WEATHER IMPACTS FOR THE AREA UNTIL THE PASSAGE OF COLD
FRONT THIS WEEKEND. FOR THIS AFTERNOON...WATER VAPOR IMAGERY
OVERLAID WITH RAP 500 MB HEIGHTS CONTINUES TO SHOW DECAYING UPPER
LEVEL SHORTWAVE TROUGH ACROSS IOWA...WHICH HAS SPREAD MID/HIGH
LEVEL CLOUDS ACROSS NORTHEAST IOWA INTO SOUTHEAST MINNESOTA. A
DOWNSTREAM UPPER LEVEL RIDGE IS HOLDING STRONG...HELPING TO KEEP
THE DRY AIR MASS IN PLACE...AS SEEN BY THE 24.12Z MPX/GRB
SOUNDINGS.
FOR TONIGHT...THE SURFACE HIGH PRESSURE REMAINS TO OUR EAST AND
OVERALL THE SURFACE PRESSURE FIELDS ARE VERY BAGGY. FORECAST
SOUNDINGS INDICATE THAT THROUGH AROUND 400 MB THE WIND FIELD IS
LESS THAN 10 KTS. AS WAS THE CASE THIS MORNING...EXPECTING PATCHY
DENSE FOG TO DEVELOP ACROSS LOW LYING AREAS OF CENTRAL
WISCONSIN...AND POSSIBLY IN THE MS AND WISCONSIN RIVER VALLEYS.
THE MORE FAVORABLE SET UP EXISTS ACROSS CENTRAL WISCONSIN BUT
COULD NOT RULE PATCHY FOG ACROSS SOUTHEAST MINNESOTA AND NORTHEAST
IOWA DURING THE EARLY MORNING HOURS. OVERALL..THE MAIN LIMITING
FACTOR FOR A MORE WIDESPREAD DENSE EVENT LOOKS TO BE THE LACK OF
SATURATION IN THE BOUNDARY LAYER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 256 CDT TUE SEP 24 2013
SOUTHWESTERLY FLOW SETS UP WEDNESDAY THROUGH THE END OF THE WORK
WEEK AS THE UPPER LEVEL PATTERN BECOMES AMPLIFIED...PROVIDING A FEW
PLEASANT AND TRANQUIL EARLY AUTUMN DAYS. A WESTERN SHORTWAVE TROUGH
BEGINS TO DIG AND MOVE EASTWARD WHILE THE DOWNSTREAM RIDGE BUILDS
ACROSS MUCH OF THE EASTERN CONUS. MOSTLY SUNNY TO SUNNY SKIES
SHOULD PREVAIL EACH DAY...WITH A GRADUAL WARMING IN HIGH
TEMPERATURES. HIGHS RANGING FROM THE LOW TO MID 70S WEDNESDAY WILL
WARM TO THE UPPER 70S TO LOWER 80S BY FRIDAY.
THE 24.12Z MODEL GUIDANCE MORE OR LESS DID NOT CHANGE THE SPEED AND
PROGRESSION OF THE WEEKEND WEATHER SYSTEM...MAYBE A TOUCH FASTER
COMPARED TO THE 00Z AND 06Z RUNS. HOWEVER...THERE IS BETTER
AGREEMENT BETWEEN THE VARIOUS DETERMINISTIC MODELS THAN PREVIOUS
MODEL CYCLES. IT APPEARS THAT THROUGH 15Z SATURDAY THE FORECAST
AREA SHOULD BE DRY WITH INCREASING MID TO HIGH LEVEL CLOUDS.
INITIAL PRECIPITATION BAND LOOKS TO SPREAD IN FROM THE WEST DURING
THE LATE MORNING HOURS...MOVING INTO WESTERN WISCONSIN DURING THE
EARLY/MID AFTERNOON. THE 24.12Z GFS REMAINS A BIT FASTER THAN THE
24.12Z GEM...WHILE THE 24.12Z CONTINUES TO BE SLOWER SOLUTION. THE
24.12Z ECMWF ATTEMPTS TO TURN THE UPPER LEVEL WAVE MORE NEGATIVELY
TILTED SATURDAY AFTERNOON...HELPING TO PUSH THE WHOLE SYSTEM EAST
OF THE AREA BY EARLY SUNDAY...IN LINE WITH ITS FASTER
COUNTERPARTS. THIS SUGGESTS GOOD CONSISTENCY FOR A DRY
SUNDAY...SO HAVE REMOVED CHANCES ALONG AND WEST OF THE MISSISSIPPI
RIVER.
IN THE WAKE OF THIS SYSTEM...ZONAL UPPER LEVEL FLOW WILL PROVIDE A
COUPLE OF DAYS OF NEAR NORMAL TEMPERATURES AND TRANQUIL WEATHER.
INDICATIONS IN THE 24.12Z ECMWF OF AN ACTIVE PACIFIC NORTHWEST JET
SUGGESTS PIECES OF FAST MOVING ENERGY THROUGH THE FLOW...WITH A
COLD FRONTAL PASSAGE TUESDAY NEXT WEEK FOLLOWED BY A REINFORCING
SHOT OF COOLER AIR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1115 PM CDT TUE SEP 24 2013
FOG DEVELOPED UNDER THE CENTER OF THE SFC HIGH EARLY THIS
MORNING...WITH WIDESPREAD VSBY REDUCTIONS ACROSS MOST OF
CENTRAL/EASTERN WI. WEST OF THERE...PRESSURE GRADIENT KEPT SFC/NEAR
SFC WINDS STIRRED MORE...PREVENTING ANY WIDESPREAD FOG DEVELOPMENT.
TONIGHT...PRESSURE GRADIENT LOOKS TO BE MORE LAX FOR THE ENTIRE
AREA...ALTHOUGH SOME HINTS IN THE BUFKIT SOUNDINGS THAT WINDS OFF
THE SFC QUICKLY INCREASE TO 10+ KTS. EXPECT SOME BR TO DEVELOP
OVERNIGHT...FAVORING MVFR 3-5SM. THAT SAID...THERE IS A THREAT FOR
SUB 1SM...ESPECIALLY IN THE RIVER VALLEYS. THE 03Z T/TD AT KLSE WAS
8 F AND IS NOT FAVORABLE FOR DENSE FOG FORMATION. WINDS AT 4 KTS
ISN/T A CLEAR SIGN ONE WAY OR THE OTHER...BUT IF IT FAVORS YES OR
NO...IT WOULD SAY NO TO DENSE FOG. CONFIDENCE REMAINS SHAKY FOR SUB
1SM FOG AT KLSE...AND WILL STAY THE COURSE WITH MVFR VSBYS FOR NOW.
OUTSIDE THE FOG THREAT...EXPECT VFR CONDITIONS TONIGHT THROUGH
WEDNESDAY. WED EVENING...MODELS POINT TO AN INCREASE IN SOME LOW
LEVEL RH WEST OF THE MISSISSIPPI RIVER ASSOCIATED WITH WEAK LOW
LEVEL MOISTURE TRANSPORT/WARM AIR ADVECTION. THIS COULD MANIFEST
INTO A SCT-BKN DECK OF 4-8 KFT CLOUDS FOR KRST...LIKELY STAYING SKC
AT KLSE. NOT ENOUGH CONFIDENCE TO ADD TO THE TAFS AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZT
LONG TERM....ZT
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1052 AM CDT WED SEP 25 2013
.DISCUSSION...
350 AM CDT
FORECAST CONCERNS CONTINUE TO FOCUS ON QUIET WEATHER WITH A GRADUAL
WARMING TREND THROUGH THE END OF THE WEEK...SHIFTING TO TIMING OF
COLD FRONT LATE SATURDAY-EARLY SUNDAY AND ASSOCIATED PRECIPITATION
CHANCES. ONLY MODEST COOLING EXPECTED BEHIND THE WEEKEND COLD FRONT
HOWEVER...WITH TEMPERATURES EXPECTED TO RISE ABOVE NORMAL EARLY NEXT
WEEK TO CLOSE OUT SEPTEMBER AND START OCTOBER.
SHORT TERM...TODAY THROUGH FRIDAY NIGHT.
SURFACE HIGH PRESSURE REMAINS TO OUR NORTHEAST THIS MORNING ACROSS
THE NORTHERN AND CENTRAL GREAT LAKES REGION. TO THE SOUTH...AN AREA
OF LOW PRESSURE WAS DRIFTING SOUTHEAST ACROSS THE LOWER MISSOURI AND
MISSISSIPPI VALLEYS IN ASSOCIATION WITH THE CLOSED MID-LEVEL
CIRCULATION OVER SOUTHEAST MISSOURI. AS ANTICIPATED...EASTERLY LOW
LEVEL FLOW FROM THE HIGH TO OUR NORTHEAST WAS CONTINUING TO MAINTAIN
DRY ADVECTION...WHILE PATCHY MID/HIGH CLOUDS WERE SPREADING ACROSS
THE SOUTHERN AND EASTERN PARTS OF THE CWA AROUND THE CYCLONIC
CIRCULATION TO OUR SOUTH. LIGHT/CALM WINDS AND SMALL TEMPERATURE-DEW
POINT DEPRESSIONS WERE RESULTING IN SOME SHALLOW FOG FORMATION
MAINLY WEST OF CHICAGO...WHERE SKIES WERE MAINLY CLEAR AND SURFACE
PRESSURE GRADIENT WAS A LITTLE WEAKER.
THE UPPER LOW OVER THE LOWER MISSOURI VALLEY WILL MOVE ACROSS THE
SOUTHERN TIP OF ILLINOIS THIS MORNING...AND OFF ACROSS THE OHIO
VALLEY AND CENTRAL APPALACHIANS TO THE MID-ATLANTIC REGION THROUGH
TONIGHT. PATCHY CLOUD COVER WILL CONTINUE TO AFFECT MAINLY THE EAST
AND SOUTHEAST PARTS OF THE CWA TODAY AS THE UPPER DISTURBANCE PULLS
SLOWLY AWAY...WITH ANY PRECIPITATION REMAINING WELL SOUTH OF THE
FORECAST AREA. A LARGE...HIGHLY AMPLIFIED UPPER TROUGH DEVELOPING
OVER THE WESTERN CONUS WILL HELP INDUCE RE-DEVELOPMENT OF AN EQUALLY
HIGH AMPLITUDE UPPER RIDGE ACROSS THE MISSISSIPPI VALLEY AND WESTERN
LAKES REGION TONIGHT AND THURSDAY IN THE WAKE OF THE DEPARTING UPPER
LOW. THIS WILL HELP RE-ESTABLISH THE SURFACE RIDGE AXIS FROM THE
MID-MISSISSIPPI VALLEY NORTHEAST INTO QUEBEC...MAINTAINING MOSTLY
CLEAR SKIES AND EAST-NORTHEAST FLOW WHICH WILL GRADUALLY SHIFT MORE
SOUTH-SOUTHEAST THROUGH FRIDAY AS THE UPPER/SURFACE RIDGE AXES DRIFT
EAST. THIS WILL ALLOW FOR A SLOW BUT STEADY WARMING TREND TO
CONTINUE THROUGH FRIDAY...THOUGH IMPEDED ACROSS NORTHEAST ILLINOIS
BY ONSHORE FLOW OFF THE LAKE. TRUE LAKE-COOLING WILL DECREASE A BIT
THURSDAY AND MORESO FRIDAY AS SURFACE WIND BECOMES MORE SOUTHEAST.
MODELS ARE IN GENERALLY GOOD AGREEMENT THERMALLY...SUPPORTING HIGHS
IN THE 70S TODAY AND THURSDAY (THOUGH APPROACHING 80
SOUTH/SOUTHWEST) AND IN THE LOWER 80S MOST AREAS AWAY FROM LAKE
MICHIGAN FRIDAY. NIGHTS WILL REMAIN SEASONABLY COOL INITIALLY WITH
UPPER 40S AND LOWER 50S FOR LOWS...MODERATING TO MID/UPPER 50S BY
FRIDAY MORNING.
MID-TERM...SATURDAY/SUNDAY.
MODEL GUIDANCE CONTINUES TO ADJUST TIMING OF COLD FRONT OVER THE
WEEKEND...WITH RECENT RUNS HAVING SPED UP THE PROGRESSION A BIT
SINCE YESTERDAY. 00Z ECMWF THE MOST RECENT TO TREND TOWARD AN
EARLIER ARRIVAL OF THE COLD FRONT...SOMETIME SATURDAY EVENING ACROSS
NORTHERN IL...AND EXITING NORTHWEST INDIANA EARLY SUNDAY. THIS MOVES
UP THE ARRIVAL AND DEPARTURE OF RAIN/SHOWER CHANCES AS WELL...TO
SATURDAY AFTERNOON/NIGHT IN THE FAR WEST AND FOR SATURDAY NIGHT AND
SUNDAY MORNING IN THE EAST. RECENT MODEL CONSENSUS HAS THE CWA DRY
SUNDAY AFTERNOON. STRONG FORCING DEPICTED WITH APPROACH OF UPPER
TROUGH AND LOW LEVEL FRONTAL ZONE...ALONG WITH NARROW BAND OF DEEPER
MOISTURE (PWATS IN EXCESS OF 1.8 INCHES PER GFS RUNS) RETURNING
ALONG THE FRONT SUPPORTS A DECENT CHANCE OF RAIN/SHOWERS WITH THE
FRONTAL PASSAGE. LAPSE RATES CONTINUE TO LOOK MEAGER...WITH VERY
WEAK/SKINNY CAPE PROFILES SUGGESTING ONLY ISOLATED THUNDER
POTENTIAL. SATURDAY CONTINUES TO HAVE THE POTENTIAL TO BE IN THE 80S
CWA-WIDE...AS THERMAL RIDGE AHEAD OF THE FRONT SPREADS ACROSS THE
AREA AND SOUTH-SOUTHWEST WINDS OVERCOME ANY SIGNIFICANT LAKE
COOLING. INCREASING CLOUD COVER WITH BE THE MAIN ISSUE FIGHTING
AGAINST THE TEMP CLIMB HOWEVER AND ADDS COMPLEXITY AND LOWER
CONFIDENCE TO THE MAX TEMP FORECAST SATURDAY AFTERNOON. WEAK HIGH
PRESSURE THEN DEVELOPS IN THE WAKE OF THE COLD FRONT SUNDAY
AFTERNOON AND SUNDAY NIGHT...THOUGH AIR BEHIND THE FRONT IS NOT
SIGNIFICANTLY COOLER. TEMPS EXPECTED RIGHT AROUND NORMAL (UPPER 60S
TO LOWER 70S) SUNDAY.
LONG TERM...MONDAY/TUESDAY.
LONG RANGE MODELS TREND THE UPPER FLOW MORE ZONAL BEHIND THE WEEKEND
TROUGH. WEAK SURFACE HIGH SLIDES OFF TO THE EAST OF THE AREA
MONDAY/TUESDAY...ALLOWING A GRADUAL RETURN TO SOUTHEAST AND THEN
SOUTH LOW LEVEL FLOW. BOTH GFS/ECMWF INDICATE A TROUGH DEVELOPING
ACROSS THE CANADIAN PRAIRIES/NORTHERN PLAINS...WHICH INCREASES SOUTH
RETURN FLOW AND WARM ADVECTION. TEMPS LOOK TO CLIMB BACK ABOVE
NORMAL MONDAY AND TUESDAY...BACK WELL INTO THE 70S IF NOT A FEW 80S
AGAIN BY TUESDAY TO START OCTOBER ON A WARM NOTE.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* NONE.
JEE
//DISCUSSION...UPDATED 12Z...
ONLY MINOR CONCERN THIS PERIOD IS THE POTENTIAL FOR LIGHT FOG...
BOTH THIS MORNING AND AGAIN TONIGHT INTO THURSDAY MORNING THOUGH
NOT EXPECTING ANY IMPACTS AT ORD/MDW. LIGHT FOG WITH MAINLY MVFR
VIS CONTINUES ACROSS MUCH OF NORTHWEST IL AND THIS WILL QUICKLY
LIFT AFTER SUNRISE. SLIGHTLY WARMER URBAN/LAKE EASTERLY FLOW IS
LIKELY HINDERING ANY FOG DEVELOPMENT AT ORD/MDW. WITH LITTLE
CHANGE TO THE AIRMASS...SIMILAR CONDITIONS EXPECTED AGAIN TONIGHT.
OTHERWISE...HIGH PRESSURE OVER THE LAKES REGION WILL CONTINUE TO
SLOWLY MOVE EAST TODAY AND TONIGHT. LIGHT EASTERLY FLOW TO START
WILL TURN NORTHEAST AND INCREASE TO 10-12KTS. SOME HIGHER GUSTS
ARE POSSIBLE ESPECIALLY THIS AFTERNOON THOUGH NOT SURE HOW
PREVAILING THEY WILL BECOME. WINDS WILL DIMINISH LATER THIS
EVENING AND POSSIBLY BECOME LIGHT AND VARIABLE OVERNIGHT INTO
THURSDAY MORNING. CMS
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT THROUGH FRIDAY NIGHT...DRY/VFR.
* SATURDAY...GUSTY SOUTHERLY WINDS POSSIBLE. CHANCE OF SHRA/TSRA
LATE.
* SATURDAY NIGHT...CHANCE OF SHRA/TSRA.
* SUNDAY THROUGH TUESDAY...DRY/VFR.
&&
.MARINE...
310 AM...A LARGE AREA OF WEAK HIGH PRESSURE OVER MUCH OF THE GREAT
LAKES WILL SLOWLY DRIFT EAST AND STRENGTHEN OVER THE NEXT FEW DAYS
AS IT MERGES WITH STRONG HIGH PRESSURE MOVING SOUTH ACROSS QUEBEC.
THE GRADIENT WILL REMAIN FAIRLY LIGHT OVER ALL BUT THE SOUTH END
OF THE LAKE THROUGH FRIDAY. A SLIGHTLY STRONGER GRADIENT WILL
DEVELOP OVER THE SOUTH THIRD OR SO OF THE LAKE LATER TODAY INTO
THIS EVENING AND WHILE SPEEDS WILL LIKELY REMAIN 10-20KTS OVER THE
NEXT 24-36 HOURS...THIS TIME PERIOD COULD BE MORE IN THE 15-20KT
RANGE. WINDS TURN BACK SOUTHEASTERLY THURSDAY NIGHT AND MORE
SOUTHERLY INTO FRIDAY NIGHT WHEN SPEEDS BEGIN TO INCREASE. THE
GRADIENT WILL TIGHTEN FRIDAY NIGHT INTO SATURDAY AHEAD OF AN
APPROACHING COLD FRONT AND THE TIMING OF THIS FRONT HAS VARIED
OVER THE PAST FEW DAYS AND NOW HAS SPED UP WITH A FRONTAL PASSAGE
SATURDAY NIGHT ACROSS LAKE MICHIGAN. SOUTHERLY WINDS 15-25KTS AHEAD
OF THE FRONT APPEAR ON TRACK WITH SOME HIGHER GUSTS POSSIBLE...
ESPECIALLY OVER THE NORTHERN PART OF THE LAKE. WINDS WILL LIKELY
SHIFT WEST/NORTHWEST BEHIND THE FRONT AND COULD BE SOMEWHAT STRONG
BEHIND THE FRONT...BUT DURATION OF STRONGER WINDS LOOKS TO BE BRIEF
WITH HIGH PRESSURE QUICKLY BUILDING INTO THE WESTERN LAKES REGION
SUNDAY AFTERNOON/EVENING. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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[top]
Area Forecast Discussion
National Weather Service Lincoln IL
1040 AM CDT Wed Sep 25 2013
.DISCUSSION...
ISSUED 1040 AM CDT Wed Sep 25 2013
Latest surface analysis shows 1009mb low centered over northwest
Tennessee. Most of the clouds and showers associated with this
feature have been confined to Kentucky this morning, however both
the HRRR and NAM suggest isolated showers may develop as far north
as southern Illinois this afternoon. Diurnal cloud cover has not
yet begun to develop, but CU-rule indicates SCT-BKN clouds developing
across the southern half of the KILX CWA. Given proximity to
lingering low pressure system and presence of slightly more humid
airmass with dewpoints in the upper 50s/lower 60s, will maintain
slight chance for showers along/south of I-70 through the
afternoon. Elsewhere, expect mostly sunny and dry conditions. High
temps will be a degree or two warmer than yesterday, generally
reaching the upper 70s and lower 80s.
Barnes
&&
.AVIATION...
ISSUED 605 AM CDT Wed Sep 25 2013
VFR conditions are expected thru this forecast period. An upper
level disturbance that produced the widely scattered showers and
storms just south of our TAF sites last night has shifted well
off to our south early this morning. We are seeing a band of
IFR cigs develop south of the TAF sites this morning, roughly
from just south of KUIN to K3LF. Latest HRRR model keeps the
lower cigs and vsbys just south of KSPI and KDEC thanks in large
part to our drier northeasterly flow. Forecast soundings do
suggest development of a sct-bkn cig from 4000-5000 feet,
especially over our southern TAF sites. Further north, the low
levels are drier and as such we are only expecting a scattered
cloud deck with bases around 4500 feet. The clouds should quickly
dissipate by this evening as drier air filters in from the
northeast and east. Look for surface winds today to be out of
the east to northeast at 8 to 13 kts and then out of the east
at 5 to 10 kts tonight.
Smith
&&
.PREV DISCUSSION...
ISSUED 235 AM CDT Wed Sep 25 2013
Upper low continues to slowly weaken as it moves southeast, and
was located just west of Effingham early this morning. Earlier
showers and scattered thunderstorms have largely diminished in our
area, with radar mosaics showing them continuing in southeast
Missouri. Skies mainly partly cloudy west of I-55, with areas to
the east under a small but concentrated patch of clouds associated
with the upper low.
The main forecast challenge remains with the cold front this
weekend, and associated rain chances.
SHORT TERM...TODAY THROUGH FRIDAY...
Will hang on to some slight chance PoPs for the southeast this
morning as the remnants of the upper low depart. Most of the model
hint at some residual PoPs along the Missouri/Illinois border
lingering into this afternoon due to a weak ribbon of energy, but
will keep our forecast dry after noon. Otherwise, high pressure
over the Great Lakes will control our weather late tonight into
Friday. Narrow upper ridge axis overhead will keep mostly clear
conditions, with highs mainly in the lower 80s.
LONG TERM...SATURDAY THROUGH TUESDAY...
Deep upper trough over the western U.S. to flatten out late this
week as it moves into the Plains. Models have begun to pick up a
bit of speed with this feature as it moves toward the Midwest,
with the GFS the most aggressive. Have included some slight
chances along the Illinois River Valley Saturday afternoon, but
currently appears that the main show will be Saturday night. Have
increased rain chances to around 60% across the west half of the
CWA, and may need to do this across the east if model trends
continue. Currently think most of the rain should be out of the
forecast area by midday, with perhaps a few showers lingering
south of I-70 into early afternoon. The fly in the ointment may be
with a developing low moving northward along the East Coast
Saturday night and Sunday. This low may slow the progression of
the front a bit, but it currently looks like the front should be
east of us before it begins to slow down.
Zonal flow sets up for early in the week, with dry weather for
Monday and Tuesday. Next rain chance would be toward midweek as a
wave moves along the Canadian border, but there is still some
uncertainty in that solution.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
632 AM CDT WED SEP 25 2013
.DISCUSSION...
350 AM CDT
FORECAST CONCERNS CONTINUE TO FOCUS ON QUIET WEATHER WITH A GRADUAL
WARMING TREND THROUGH THE END OF THE WEEK...SHIFTING TO TIMING OF
COLD FRONT LATE SATURDAY-EARLY SUNDAY AND ASSOCIATED PRECIPITATION
CHANCES. ONLY MODEST COOLING EXPECTED BEHIND THE WEEKEND COLD FRONT
HOWEVER...WITH TEMPERATURES EXPECTED TO RISE ABOVE NORMAL EARLY NEXT
WEEK TO CLOSE OUT SEPTEMBER AND START OCTOBER.
SHORT TERM...TODAY THROUGH FRIDAY NIGHT.
SURFACE HIGH PRESSURE REMAINS TO OUR NORTHEAST THIS MORNING ACROSS
THE NORTHERN AND CENTRAL GREAT LAKES REGION. TO THE SOUTH...AN AREA
OF LOW PRESSURE WAS DRIFTING SOUTHEAST ACROSS THE LOWER MISSOURI AND
MISSISSIPPI VALLEYS IN ASSOCIATION WITH THE CLOSED MID-LEVEL
CIRCULATION OVER SOUTHEAST MISSOURI. AS ANTICIPATED...EASTERLY LOW
LEVEL FLOW FROM THE HIGH TO OUR NORTHEAST WAS CONTINUING TO MAINTAIN
DRY ADVECTION...WHILE PATCHY MID/HIGH CLOUDS WERE SPREADING ACROSS
THE SOUTHERN AND EASTERN PARTS OF THE CWA AROUND THE CYCLONIC
CIRCULATION TO OUR SOUTH. LIGHT/CALM WINDS AND SMALL TEMPERATURE-DEW
POINT DEPRESSIONS WERE RESULTING IN SOME SHALLOW FOG FORMATION
MAINLY WEST OF CHICAGO...WHERE SKIES WERE MAINLY CLEAR AND SURFACE
PRESSURE GRADIENT WAS A LITTLE WEAKER.
THE UPPER LOW OVER THE LOWER MISSOURI VALLEY WILL MOVE ACROSS THE
SOUTHERN TIP OF ILLINOIS THIS MORNING...AND OFF ACROSS THE OHIO
VALLEY AND CENTRAL APPALACHIANS TO THE MID-ATLANTIC REGION THROUGH
TONIGHT. PATCHY CLOUD COVER WILL CONTINUE TO AFFECT MAINLY THE EAST
AND SOUTHEAST PARTS OF THE CWA TODAY AS THE UPPER DISTURBANCE PULLS
SLOWLY AWAY...WITH ANY PRECIPITATION REMAINING WELL SOUTH OF THE
FORECAST AREA. A LARGE...HIGHLY AMPLIFIED UPPER TROUGH DEVELOPING
OVER THE WESTERN CONUS WILL HELP INDUCE RE-DEVELOPMENT OF AN EQUALLY
HIGH AMPLITUDE UPPER RIDGE ACROSS THE MISSISSIPPI VALLEY AND WESTERN
LAKES REGION TONIGHT AND THURSDAY IN THE WAKE OF THE DEPARTING UPPER
LOW. THIS WILL HELP RE-ESTABLISH THE SURFACE RIDGE AXIS FROM THE
MID-MISSISSIPPI VALLEY NORTHEAST INTO QUEBEC...MAINTAINING MOSTLY
CLEAR SKIES AND EAST-NORTHEAST FLOW WHICH WILL GRADUALLY SHIFT MORE
SOUTH-SOUTHEAST THROUGH FRIDAY AS THE UPPER/SURFACE RIDGE AXES DRIFT
EAST. THIS WILL ALLOW FOR A SLOW BUT STEADY WARMING TREND TO
CONTINUE THROUGH FRIDAY...THOUGH IMPEDED ACROSS NORTHEAST ILLINOIS
BY ONSHORE FLOW OFF THE LAKE. TRUE LAKE-COOLING WILL DECREASE A BIT
THURSDAY AND MORESO FRIDAY AS SURFACE WIND BECOMES MORE SOUTHEAST.
MODELS ARE IN GENERALLY GOOD AGREEMENT THERMALLY...SUPPORTING HIGHS
IN THE 70S TODAY AND THURSDAY (THOUGH APPROACHING 80
SOUTH/SOUTHWEST) AND IN THE LOWER 80S MOST AREAS AWAY FROM LAKE
MICHIGAN FRIDAY. NIGHTS WILL REMAIN SEASONABLY COOL INITIALLY WITH
UPPER 40S AND LOWER 50S FOR LOWS...MODERATING TO MID/UPPER 50S BY
FRIDAY MORNING.
MID-TERM...SATURDAY/SUNDAY.
MODEL GUIDANCE CONTINUES TO ADJUST TIMING OF COLD FRONT OVER THE
WEEKEND...WITH RECENT RUNS HAVING SPED UP THE PROGRESSION A BIT
SINCE YESTERDAY. 00Z ECMWF THE MOST RECENT TO TREND TOWARD AN
EARLIER ARRIVAL OF THE COLD FRONT...SOMETIME SATURDAY EVENING ACROSS
NORTHERN IL...AND EXITING NORTHWEST INDIANA EARLY SUNDAY. THIS MOVES
UP THE ARRIVAL AND DEPARTURE OF RAIN/SHOWER CHANCES AS WELL...TO
SATURDAY AFTERNOON/NIGHT IN THE FAR WEST AND FOR SATURDAY NIGHT AND
SUNDAY MORNING IN THE EAST. RECENT MODEL CONSENSUS HAS THE CWA DRY
SUNDAY AFTERNOON. STRONG FORCING DEPICTED WITH APPROACH OF UPPER
TROUGH AND LOW LEVEL FRONTAL ZONE...ALONG WITH NARROW BAND OF DEEPER
MOISTURE (PWATS IN EXCESS OF 1.8 INCHES PER GFS RUNS) RETURNING
ALONG THE FRONT SUPPORTS A DECENT CHANCE OF RAIN/SHOWERS WITH THE
FRONTAL PASSAGE. LAPSE RATES CONTINUE TO LOOK MEAGER...WITH VERY
WEAK/SKINNY CAPE PROFILES SUGGESTING ONLY ISOLATED THUNDER
POTENTIAL. SATURDAY CONTINUES TO HAVE THE POTENTIAL TO BE IN THE 80S
CWA-WIDE...AS THERMAL RIDGE AHEAD OF THE FRONT SPREADS ACROSS THE
AREA AND SOUTH-SOUTHWEST WINDS OVERCOME ANY SIGNIFICANT LAKE
COOLING. INCREASING CLOUD COVER WITH BE THE MAIN ISSUE FIGHTING
AGAINST THE TEMP CLIMB HOWEVER AND ADDS COMPLEXITY AND LOWER
CONFIDENCE TO THE MAX TEMP FORECAST SATURDAY AFTERNOON. WEAK HIGH
PRESSURE THEN DEVELOPS IN THE WAKE OF THE COLD FRONT SUNDAY
AFTERNOON AND SUNDAY NIGHT...THOUGH AIR BEHIND THE FRONT IS NOT
SIGNIFICANTLY COOLER. TEMPS EXPECTED RIGHT AROUND NORMAL (UPPER 60S
TO LOWER 70S) SUNDAY.
LONG TERM...MONDAY/TUESDAY.
LONG RANGE MODELS TREND THE UPPER FLOW MORE ZONAL BEHIND THE WEEKEND
TROUGH. WEAK SURFACE HIGH SLIDES OFF TO THE EAST OF THE AREA
MONDAY/TUESDAY...ALLOWING A GRADUAL RETURN TO SOUTHEAST AND THEN
SOUTH LOW LEVEL FLOW. BOTH GFS/ECMWF INDICATE A TROUGH DEVELOPING
ACROSS THE CANADIAN PRAIRIES/NORTHERN PLAINS...WHICH INCREASES SOUTH
RETURN FLOW AND WARM ADVECTION. TEMPS LOOK TO CLIMB BACK ABOVE
NORMAL MONDAY AND TUESDAY...BACK WELL INTO THE 70S IF NOT A FEW 80S
AGAIN BY TUESDAY TO START OCTOBER ON A WARM NOTE.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* NONE. CMS
//DISCUSSION...UPDATED 12Z...
ONLY MINOR CONCERN THIS PERIOD IS THE POTENTIAL FOR LIGHT FOG...
BOTH THIS MORNING AND AGAIN TONIGHT INTO THURSDAY MORNING THOUGH
NOT EXPECTING ANY IMPACTS AT ORD/MDW. LIGHT FOG WITH MAINLY MVFR
VIS CONTINUES ACROSS MUCH OF NORTHWEST IL AND THIS WILL QUICKLY
LIFT AFTER SUNRISE. SLIGHTLY WARMER URBAN/LAKE EASTERLY FLOW IS
LIKELY HINDERING ANY FOG DEVELOPMENT AT ORD/MDW. WITH LITTLE
CHANGE TO THE AIRMASS...SIMILAR CONDITIONS EXPECTED AGAIN TONIGHT.
OTHERWISE...HIGH PRESSURE OVER THE LAKES REGION WILL CONTINUE TO
SLOWLY MOVE EAST TODAY AND TONIGHT. LIGHT EASTERLY FLOW TO START
WILL TURN NORTHEAST AND INCREASE TO 10-12KTS. SOME HIGHER GUSTS
ARE POSSIBLE ESPECIALLY THIS AFTERNOON THOUGH NOT SURE HOW
PREVAILING THEY WILL BECOME. WINDS WILL DIMINISH LATER THIS
EVENING AND POSSIBLY BECOME LIGHT AND VARIABLE OVERNIGHT INTO
THURSDAY MORNING. CMS
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM FOR WIND SPEEDS/DIRECTIONS THROUGH THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
* THURSDAY NIGHT THROUGH FRIDAY NIGHT...DRY/VFR.
* SATURDAY...GUSTY SOUTHERLY WINDS POSSIBLE. CHANCE OF SHRA/TSRA
LATE.
* SATURDAY NIGHT...CHANCE OF SHRA/TSRA.
* SUNDAY THROUGH TUESDAY...DRY/VFR.
&&
.MARINE...
310 AM...A LARGE AREA OF WEAK HIGH PRESSURE OVER MUCH OF THE GREAT
LAKES WILL SLOWLY DRIFT EAST AND STRENGTHEN OVER THE NEXT FEW DAYS
AS IT MERGES WITH STRONG HIGH PRESSURE MOVING SOUTH ACROSS QUEBEC.
THE GRADIENT WILL REMAIN FAIRLY LIGHT OVER ALL BUT THE SOUTH END
OF THE LAKE THROUGH FRIDAY. A SLIGHTLY STRONGER GRADIENT WILL
DEVELOP OVER THE SOUTH THIRD OR SO OF THE LAKE LATER TODAY INTO
THIS EVENING AND WHILE SPEEDS WILL LIKELY REMAIN 10-20KTS OVER THE
NEXT 24-36 HOURS...THIS TIME PERIOD COULD BE MORE IN THE 15-20KT
RANGE. WINDS TURN BACK SOUTHEASTERLY THURSDAY NIGHT AND MORE
SOUTHERLY INTO FRIDAY NIGHT WHEN SPEEDS BEGIN TO INCREASE. THE
GRADIENT WILL TIGHTEN FRIDAY NIGHT INTO SATURDAY AHEAD OF AN
APPROACHING COLD FRONT AND THE TIMING OF THIS FRONT HAS VARIED
OVER THE PAST FEW DAYS AND NOW HAS SPED UP WITH A FRONTAL PASSAGE
SATURDAY NIGHT ACROSS LAKE MICHIGAN. SOUTHERLY WINDS 15-25KTS AHEAD
OF THE FRONT APPEAR ON TRACK WITH SOME HIGHER GUSTS POSSIBLE...
ESPECIALLY OVER THE NORTHERN PART OF THE LAKE. WINDS WILL LIKELY
SHIFT WEST/NORTHWEST BEHIND THE FRONT AND COULD BE SOMEWHAT STRONG
BEHIND THE FRONT...BUT DURATION OF STRONGER WINDS LOOKS TO BE BRIEF
WITH HIGH PRESSURE QUICKLY BUILDING INTO THE WESTERN LAKES REGION
SUNDAY AFTERNOON/EVENING. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
National Weather Service Lincoln IL
619 AM CDT Wed Sep 25 2013
.DISCUSSION...
ISSUED 235 AM CDT Wed Sep 25 2013
Upper low continues to slowly weaken as it moves southeast, and
was located just west of Effingham early this morning. Earlier
showers and scattered thunderstorms have largely diminished in our
area, with radar mosaics showing them continuing in southeast
Missouri. Skies mainly partly cloudy west of I-55, with areas to
the east under a small but concentrated patch of clouds associated
with the upper low.
The main forecast challenge remains with the cold front this
weekend, and associated rain chances.
SHORT TERM...TODAY THROUGH FRIDAY...
Will hang on to some slight chance PoPs for the southeast this
morning as the remnants of the upper low depart. Most of the model
hint at some residual PoPs along the Missouri/Illinois border
lingering into this afternoon due to a weak ribbon of energy, but
will keep our forecast dry after noon. Otherwise, high pressure
over the Great Lakes will control our weather late tonight into
Friday. Narrow upper ridge axis overhead will keep mostly clear
conditions, with highs mainly in the lower 80s.
LONG TERM...SATURDAY THROUGH TUESDAY...
Deep upper trough over the western U.S. to flatten out late this
week as it moves into the Plains. Models have begun to pick up a
bit of speed with this feature as it moves toward the Midwest,
with the GFS the most aggressive. Have included some slight
chances along the Illinois River Valley Saturday afternoon, but
currently appears that the main show will be Saturday night. Have
increased rain chances to around 60% across the west half of the
CWA, and may need to do this across the east if model trends
continue. Currently think most of the rain should be out of the
forecast area by midday, with perhaps a few showers lingering
south of I-70 into early afternoon. The fly in the ointment may be
with a developing low moving northward along the East Coast
Saturday night and Sunday. This low may slow the progression of
the front a bit, but it currently looks like the front should be
east of us before it begins to slow down.
Zonal flow sets up for early in the week, with dry weather for
Monday and Tuesday. Next rain chance would be toward midweek as a
wave moves along the Canadian border, but there is still some
uncertainty in that solution.
Geelhart
&&
.AVIATION...
ISSUED 605 AM CDT Wed Sep 25 2013
VFR conditions are expected thru this forecast period. An upper
level disturbance that produced the widely scattered showers and
storms just south of our TAF sites last night has shifted well
off to our south early this morning. We are seeing a band of
IFR cigs develop south of the TAF sites this morning, roughly
from just south of KUIN to K3LF. Latest HRRR model keeps the
lower cigs and vsbys just south of KSPI and KDEC thanks in large
part to our drier northeasterly flow. Forecast soundings do
suggest development of a sct-bkn cig from 4000-5000 feet,
especially over our southern TAF sites. Further north, the low
levels are drier and as such we are only expecting a scattered
cloud deck with bases around 4500 feet. The clouds should quickly
dissipate by this evening as drier air filters in from the
northeast and east. Look for surface winds today to be out of
the east to northeast at 8 to 13 kts and then out of the east
at 5 to 10 kts tonight.
Smith
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
1052 AM EDT WED SEP 25 2013
.UPDATE...
ISSUED AT 1052 AM EDT WED SEP 25 2013
SHOWERS WHICH AFFECTED MOST PLACES FROM KJKL SOUTH WERE LARGELY ON
THE WAY OUT LATE THIS MORNING. 12Z NAM AND LATEST HRRR STILL GENERATE
MORE CONVECTION DURING THE AFTERNOON...ESPECIALLY OVER THE SOUTHERN
PART OF THE AREA. HAVE UPDATED POPS FOR THE REMAINDER OF THE
DAY...WITH THE MAIN CHANGE BEING A DROP BACK TO NOTHING MORE THAN
LIKELY POPS FOR MOST PLACES IN THE SOUTH. HAVE LEFT A SLIGHT CHANCE
OF THUNDER IN FOR THE SOUTH...BUT EXPECTED INSTABILITY REALLY LOOKS
MEAGER.
UPDATE ISSUED AT 755 AM EDT WED SEP 25 2013
DID A QUICK GRID UPDATE TO FINE TUNE POPS THROUGH THE NEXT SEVERAL
HOURS BASED ON THE LATEST RADAR TRENDS AND HRRR/RAP13. ALSO TWEAKED
T/TD GRIDS PER THE LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE
NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 400 AM EDT WED SEP 25 2013
07Z SFC ANALYSIS SHOWS A BROAD AREA OF WEAK LOW PRESSURE MOVING
THROUGH THE TENNESSEE VALLEY AND PUSHING INTO SOUTHEAST KENTUCKY.
THIS IS BRINGING A BATCH OF NUMEROUS TO SCATTERED SHOWERS TO THE
CUMBERLAND VALLEY EARLY THIS MORNING. A FEW LIGHTNING STRIKES
ASSOCIATED WITH THIS AREA EARLIER IN THE NIGHT HAVE ENDED FOR NOW.
LOW AND MID LEVEL CLOUDS CURRENTLY COVER EAST KENTUCKY AND THESE ARE
HELPING TO KEEP ANY FOG AT BAY. THESE CLOUDS ARE ALSO SUPPORTING
MILDER TEMPS OVERNIGHT WITH READINGS VARYING FROM THE UPPER 50S IN
THE NORTHEAST TO MID AND UPPER 60S IN THE SOUTHWEST. MEANWHILE...
WINDS ARE LIGHT THROUGH THE CWA AND DEW POINTS VARY FROM THE UPPER 50S
IN THE NORTH TO THE MID 6OS IN THE SOUTH.
THE MODELS HAVE SETTLED ON A SOLUTION ALOFT FOR THE SHORT TERM THAT
CONSISTS OF A BROAD TROUGH CROSSING INTO THE OHIO VALLEY EARLY THIS
MORNING AND ROLLING EAST ACROSS THE SPINE OF THE CENTRAL APPALACHIANS
BY THURSDAY MORNING. RIDGING EVENTUALLY FOLLOWS THIS FOR THURSDAY
EVENING...BUT NOT BEFORE CYCLONIC MID LEVEL FLOW DEPARTS LATE
THURSDAY AFTERNOON. WHILE THE MODELS ARE IN PRETTY GOOD AGREEMENT
WITH THIS EVOLUTION...THERE REMAINS SOME SUBSTANTIAL QPF DIFFERENCES
THROUGH THE CWA TODAY AND CONSISTENCY WITH THIS AND OTHER SENSIBLE
PARAMETERS HAVE BEEN BELOW AVERAGE WITH THIS SYSTEM. ACCORDINGLY...
HAVE FOLLOWED THE LATEST HRRR...NAM12...AND ECMWF MOST CLOSELY FOR WX
SPECIFICS THROUGH THE SHORT TERM.
SENSIBLE WEATHER WILL FEATURE SHOWERS AND EVENTUALLY EMBEDDED
THUNDERSTORMS MOVING INTO EAST KENTUCKY FROM WEST TO EAST...MAINLY
TARGETING THE SOUTHERN HALF OF THE CWA. THAT SAID...THE LATEST HRRR
AND RAP13 DEPICT THE HIGHER POPS AND BETTER QPF A BIT FARTHER NORTH
TODAY THAN THE NAM12 AND ECMWF SUGGEST. FOR THAT REASON HAVE LIFTED
THE HIGHER POPS AND SOME QPF A BIT NORTH OF MODEL CONSENSUS. POCKETS
OF HEAVIER RAIN FROM LONGER DURATION SHOWERS...AND A POTENTIAL FOR
TRAINING...WILL LIKELY LEAVE BEHIND UP TO AN INCH OF RAIN IN SOME
PLACES THROUGHOUT THE CUMBERLAND VALLEY. WILL ADD THIS MENTION TO
THE HWO. THE SYSTEM PULLS AWAY TONIGHT AND ENDS ALL BUT AN ISOLATED
SHOWER PCPN THREAT FOR THE AREA DURING THE EVENING. LOW CLOUDS WILL
BREAK UP DURING THE MORNING ON THURSDAY WITH GOOD AMOUNTS OF SUNSHINE
RETURNING BY AFTERNOON. IN THE FAR EAST...CLOUDS WILL LINGER LONGER
ALONG WITH A SMALL THREAT FOR A SHOWER IN THE MORNING.
USED THE CONSSHORT AND ITS BC VERSION TO INITIATE THE TD AND WIND
GRIDS THROUGH 00Z THURSDAY...THEN THE BC/CONSALL THEREAFTER. FOR
TEMPERATURES...USED THE CONSSHORT THROUGH MID MORNING BLENDED WITH A
DIURNAL CURVE BASED ON THE NAM12 AFTER SLIGHTLY MODIFYING THE
CONSALL MAX AND MIN TEMPS. AS FOR POPS...ENDED UP A TAD CLOSER TO
THE HIGHER MET NUMBERS THROUGH TONIGHT AND THEN WENT MAINLY DRY ON
THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 234 AM EDT WED SEP 25 2013
A STRONG RIDGE OF HIGH PRESSURE WILL BUILD OVER THE AREA FROM
THURSDAY NIGHT THROUGH SATURDAY PROVIDING A DRY AND PLEASANT STRETCH
OF WEATHER. THE NEXT CHANCE OF RAIN WILL HOLD OFF UNTIL LATE SUNDAY
AND SUNDAY NIGHT AS A FAST MOVING SHORTWAVE PUSHES A COLD FRONT
ACROSS KENTUCKY. MODELS STILL DIFFER ON TIMING AND STRENGTH OF THIS
SYSTEM...BUT OVERALL...THIS FEATURE HAS LOOKED WEAKER AND WEAKER
OVER THE PAST FEW DAYS WITH THE FORCING ALMOST NON-EXISTENT.
THUS...ONLY GOING TO CARRY SLIGHT CHANCE POPS WITH THIS BOUNDARY AS
IT PUSHES ACROSS THE AREA LATE IN THE WEEKEND. THE ECMWF HOLDS THE
FRONT UP NEAR THE AREA ON MONDAY...PERHAPS ALLOWING FOR A FEW
SHOWERS INTO MONDAY AFTERNOON. HOWEVER...THE TENDENCY IS TO DRY
THINGS OUT FROM MONDAY NIGHT INTO THE MIDDLE OF NEXT WEEK. A GOOD
CHANCE MOST OF THE EXTENDED WILL REMAIN DRY FOR MOST OF THE AREA.
TEMPERATURES WILL TREND SLIGHTLY ABOVE NORMAL FOR THE END OF THE
WEEK INTO SATURDAY...BEFORE A SLIGHT DIP FOR SUNDAY AND MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 805 AM EDT WED SEP 25 2013
AS A WEAK AREA OF LOW PRESSURE CROSS SOUTHEAST KENTUCKY...SHOWERS
WILL CONTINUE TO OVERSPREAD THE CUMBERLAND VALLEY THIS MORNING WITH
ISOLATED THUNDERSTORMS POSSIBLE. THIS SYSTEM WILL DRAG THROUGH THE
LOWER HALF OF EAST KENTUCKY TODAY AND BRING A BETTER CHANCE OF
THUNDER TO THE TAF SITES FROM LATE MORNING INTO THE AFTERNOON. THE
HEAVIER SHOWERS ASSOCIATED WITH THIS PASSAGE SHOULD BE ENOUGH TO
LOWER CIGS AND VIS DOWN TO MVFR...AND PROBABLY BRIEFLY IFR...THROUGH
THE AFTERNOON. THE SHOWERS WILL LIKELY END FROM NORTHWEST TO
SOUTHEAST LATER THIS EVENING AS VFR CIGS AND VIS RETURN. WINDS WILL
REMAIN LIGHT AND VARIABLE THROUGH THE TAF PERIOD...EXCEPT IN THE
IMMEDIATE VICINITY OF ANY STRAY STORM.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1028 AM CDT WED SEP 25 2013
.UPDATE...
ISSUED AT 1018 AM CDT WED SEP 25 2013
MAIN FOCUS IN SHORT TERM IS EXTENSION OF FOG/STRATUS DECK
EXTENDING FROM LAKE SUPERIOR INLAND TO SRN CARLTON COUNTY. HI RES
MDL SFC COND PRESS DEFICITS SEEM TO REASONABLY HANDLE THE FEATURE
. SHOULD HAVE A PERIOD OF CLEARING/IMPROVEMENT THIS AFTN BEFORE
REDEVELOPMENT INLAND AGAIN THIS EVENING. HRRR 3KM/DLHWRF SHOWS
INCREASING NE WIND INTO HEAD OF LAKE LATER TODAY WHICH MAY PUSH
STRATUS/FG INLAND SOONER THAN CURRENTLY FCST. HAVE ADJUSTED SKY/WX
GRIDS TO ACCOUNT FOR STRATUS/FG. ALTHOUGH WARMING HAS BEEN DELAYED...FCST
MAX TEMPS HAVE AN OPPORTUNITY TO REACH INTO 60S NEAR LAKE.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY AFTERNOON)
ISSUED AT 322 AM CDT WED SEP 25 2013
MAIN CONCERNS IN THE SHORT TERM ARE FOCUSED AROUND THE AREAS OF
FOG THIS MORNING...WITH LOCALLY DENSE CONDITIONS THROUGH 9
AM...AND GUSTY SOUTH WINDS THIS AFTERNOON...AND AGAIN THURSDAY
AFTERNOON. TEMPERATURES AROUND THE TWIN PORTS AND THE PERIPHERY OF
LAKE SUPERIOR WILL ALSO BE AN AREA OF ATTENTION IN THE SHORT TERM.
HIGH PRESSURE AT THE SURFACE OVER THE GREAT LAKES AND UPPER LEVEL
RIDGING ACROSS THE UPPER MIDWEST WILL KEEP CONDITIONS VERY QUIET
IN THE SHORT TERM...THROUGH THURSDAY AFTERNOON. WEAK WAA IN THE
MID/LOW LEVELS THIS MORNING HAS ALLOWED A SHARP INVERSION TO FORM
AND...COMBINED WITH LIGHT/CALM WINDS AND A SHALLOW MOIST LAYER TO
PRODUCE AREAS OF FOG...WITH VISIBILITIES DOWN TO A HALF MILE OR
LESS AT TIMES IN ISOLATED LOCATIONS. AFTER SUNRISE THIS
MORNING...SHOULD SEE FOG BURN OFF BY 9-10 AM.
SKIES WILL REMAIN MOSTLY SUNNY TODAY WITH HIGHS VERY SIMILAR TO
YESTERDAY...INTO THE UPPER 60S AROUND LAKE SUPERIOR...AND LOWER TO
MID 70S INLAND. IN RESPONSE TO HIGH PRESSURE TO THE EAST AND
STRONG CYCLOGENESIS OVER THE WRN DAKOTAS/NE/WY AREA THIS
AFTERNOON AND TONIGHT...WILL SEE S/SE WINDS INCREASE. A TIGHTENING
SFC PRES GRADIENT COMBINED WITH MODEST BL MIXING WILL PRODUCE
SUSTAINED WINDS AROUND 10 TO 15 MPH AND GUSTS 20 TO 25
MPH...ESPECIALLY OVER NE MN. LIGHTER WINDS ARE EXPECTED TO THE
EAST INTO NW WI.
THE SFC PRESSURE FALLS TO THE WEST WILL CONTINUE ON THURSDAY AS
THE LOW DEVELOPS AND LIFTS TO THE NE THROUGH THE DAKOTAS. THE
STRENGTHENING SYSTEM WILL ALLOW THE SOUTH WINDS TO BE EVEN
STRONGER ON THURSDAY WITH SUSTAINED WINDS AROUND 15 TO 20
MPH...AND GUSTS UP TO 30 MPH. THE INCREASE IN WINDS THURSDAY WILL
ALSO DRAW UP A WARMER AND MORE HUMID AIR MASS...WITH TEMPERATURES
REACHING INTO THE MID TO UPPER 70S...CLOSE TO 80 OVER NE MN...AND
INTO THE LOWER TO MID 70S IN WI. DWPTS WILL RISE INTO THE MID TO
UPPER 50S. EVEN THOUGH MOST OF THE FORECAST AREA WILL SEE S/SE
WINDS...WINDS ACROSS WRN LAKE SUPERIOR WILL BE E/NELY AND STRONG
ENOUGH TO ALLOW THE COOLER AIR OVER THE LAKE TO SPILL INTO THE
NEAR LAKE AREAS...INCLUDING THE TWIN PORTS. THE DULUTH/SUPERIOR
AREA ON THUR COULD ACTUALLY ONLY SEE HIGHS IN THE UPPER 60S.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 322 AM CDT WED SEP 25 2013
GFS AND 00Z ECMWF ARE THE QUICKEST WITH THE SYSTEM EXPECTED TO
AFFECT THE FA THROUGH THE WEEKEND. THEY BRING RAIN TO THE WESTERN
EDGE LATE THURSDAY NIGHT. MEANWHILE...THE GEM/NAM KEEP THE RAIN OUT
OF THE AREA THURSDAY NIGHT. HOWEVER...ON FRIDAY ALL MODELS BRING
RAIN WITH SOME ISOLD THUNDER TO ALL BUT NW WI AS DRY AIR HANGS ON
FROM THE HIGH OVER THE EASTERN GREAT LAKES. HAVE KEPT NW WI DRY ON
FRIDAY AND BEGUN TO RAMP UP POPS OVER THE WESTERN THIRD OF THE FA.
THIS AREA WILL BE UNDER STRONG SW FLOW WITH H85 LLJ TO 45 KT AND
EMBEDDED PIECES OF ENERGY IN THE STRONG FLOW MOVING OVER THIS AREA
THROUGH THE DAY. ON FRIDAY NIGHT...THE RIDGING OVER NW WI BEGINS TO
BREAK DOWN AS VIGOROUS UPPER LEVEL TROF MOVES THROUGH THE NORTHERN
PLAINS. ATTENDANT COLD FRONT WILL BE SOMEWHERE OVER NE MN FRIDAY
NIGHT...BUT TIMING DIFFERENCES AMONGST THE MODELS MAKE IT DIFFICULT
TO PINPOINT. HAVE MENTIONS OF ISOLD THUNDER FRIDAY NIGHT WITH GOOD
INSTABILITY IN PLACE. UPPER TROF WILL BE OVERHEAD ON SATURDAY WITH
RAIN CHANCES INCREASING ACROSS THE AREA. THINGS BEGIN TO WIND DOWN
SATURDAY NIGHT AS THE UPPER TROF PUSHES E OF THE FA. HAVE TRENDED
THE POPS ACCORDINGLY. LINGERED SOME POPS OVER THE EASTERN NW WI AREA
DUE TO TIMING ISSUES AMONGST THE MODELS SUNDAY MORNING. DID REMOVE
THE RAIN MENTION SUNDAY AFTERNOON WITH QUASI-ZONAL FLOW SETTING UP.
NEXT OPPORTUNITY FOR RAIN COMES INTO FOCUS ON TUESDAY AS NEXT COLD
FRONT IS DUE TO CROSS THE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 620 AM CDT WED SEP 25 2013
AREAS OF FOG/BR WITH IFR/LIFR CIGS/VSBYS WILL QUICKLY ERODE THIS
MORNING AS A SOUTHERLY FLOW SETS UP. CIGS/VSBYS WILL BE VFR
THROUGH THE REMAINDER OF THE FORECAST PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 69 49 72 60 / 0 0 0 10
INL 73 48 75 58 / 0 0 0 10
BRD 73 53 81 62 / 0 0 0 10
HYR 71 45 74 55 / 0 0 0 0
ASX 69 44 72 56 / 0 0 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...CANNON
SHORT TERM...BJT
LONG TERM...GSF
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
741 AM EDT WED SEP 25 2013
.SYNOPSIS...
SLOW MOVING LOW PRESSURE OVER THE CANADIAN MARITIMES WILL
CONTINUE TO FILTER IN MOISTURE FROM THE NORTH INTO VERMONT AND
PORTIONS OF NORTHERN NEW YORK...BRINGING PERIODS OF PARTLY CLOUDY
TO MOSTLY CLOUDY SKIES TODAY THROUGH FRIDAY. SURFACE HIGH
PRESSURE LOCATED OVER THE GREAT LAKES WILL SLOWLY BUILD TOWARD
THE NORTH COUNTRY WITH MOSTLY SUNNY SKIES AND TEMPERATURES
TRENDING WARMER INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 715 AM EDT WEDNESDAY...MINOR ADJUSTMENTS TO CURRENT
FCST...REFLECTING SATELLITE TRENDS...AS STRATUS DECK HAS
RETREATED FROM ALL BUT THE NEK. IR SATELLITE ALSO SHOWS AREA OF
MOISTURE SURGING MORE EWD UPSTREAM. RUC SHOWS CLOUDS FROM THIS
AREA MOVING INTO NORTH COUNTRY THIS AFTN...MORE SO THAN OTHER
MODELS...BUT SIMILAR IN TREND. HAVE INCREASED CLDS OVER NEK THIS
AFTN AND INTO THE ADKS. HAVE ALSO ADJUSTED TEMPS TO ACCOUNT FOR
COOLER TEMPS THIS MORNING.
PREVIOUS DISC...AT THE SFC...HIGH PRESSURE CONTINUES TO BUILD
OVER THE GREAT LAKES TODAY...WHILE THE VERTICALLY STACKED LOW
GRADUALLY PICKS UP A LITTLE MOMENTUM EWD LATE IN THE DAY INTO
TONIGHT. WITH THE CYCLONIC FLOW AROUND THIS LOW...SOME LOW CLOUDS
STILL EXPECTED...BUT SATELLITE IMAGERY SHOWS SHRINKING AREA OF
MOISTURE AS SUBSIDENCE OVER THE ERN GREAT LAKES SLOWLY SPREADS
EAST. EXPECT MOST OF THE AREA TO BE MOSTLY SUNNY THRU
MIDDAY...WITH EXCEPTION OF NEK. MODELS SHOW ANOTHER SURGE OF
LLVL/SHALLOW MOISTURE LATE THIS AFTN INTO OVERNIGHT. AREAS
EXPECTING TO STAY MORE ON THE SUNNY SIDE...SUCH AS SLV AND CT
VALLEY WILL SEE MAX TEMPS NEAR 70F IN THE SLV TO M/U 60S IN THE
CPV AND 50S- L60S IN NEK/MTNS.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH FRIDAY/...
AS OF 443 AM EDT WEDNESDAY...LITTLE CHANGE IN LARGE SCALE PATTERN
ANTICIPATED AS BLOCK FLOW ALOFT CONTINUES TONIGHT INTO THURSDAY.
WITH THE LOW TO OUR E CONTINUING TO FILTER IN LLVL
MOISTURE...CLOUDS WILL BE A TRICKY FCST...AS ALL GUIDANCE SHOWS
PLENTY OF MOISTURE TRAPPED BELOW THE TEMP INVERSION THRU
THURSDAY. LATE THURSDAY INTO FRIDAY WE FINALLY BREAK FREE OF
CYCLONIC FLOW FROM THE LOW PRESSURE SYSTEM AS IT SHIFTS MORE
EASTERLY. SFC HIGH PRESSURE WILL CREST OVER THE REGION ON FRIDAY
WITH CLEARING SKIES.
TEMPERATURES WILL BE NOTICEABLY WARMER IN AREAS THAT SEE THE MOST
SUN DURING THE DAY MAINLY IN THE SLV ON THURSDAY...WITH MAX TEMPS
AROUND 70F...U60S IN CPV AND L-M60S ELSEWHERE...WITH THE MTNS IN
THE 50S. TEMPS ALOFT TRENDING WARMER BY A DEGREE OR TWO EACH
DAY...THEREFORE THURS NT TEMPS WILL BE SIMILAR TO THAT OF
TONIGHT...AS WARMER TEMPS ALOFT WILL BE OFFSET BY DIMINISHING
CLOUDS. FRIDAY WILL BE THE WARMEST DAY WITH TEMPS NEARING 5
DEGREES ABOVE NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 401 AM EDT WEDNESDAY... MODELS GENERALLY IN GOOD AGREEMENT
THROUGH THE PERIOD LEADING TO DECENT FORECASTER CONFIDENCE FOR
FINE LEAF PEEPING WEATHER.
FRIDAY NIGHT INTO SUNDAY MASSIVE RIDGE ALONG AND HIGH PRESSURE AT
THE SURFACE WILL LEAD TO MAINLY CLEAR SKIES, COOL MORNINGS IN THE
30S AND 40S AND MILD AFTERNOONS IN THE UPPER 60S TO MID 70S.
THESE ARE LARGER THAN AVERAGE DIURNAL TEMP RANGES AND HAVE GONE
3-5 DEGREES LOWER THAN GUIDANCE FOR MINS ESPECIALLY ON SAT AND A
COUPLE DEGREES ON SUNDAY BUT HIGH TEMPS SEEM ABOUT RIGHT.
LOTS OF CONVECTION CURRENTLY OVER THE SOUTHEAST US AS UPPER TROF
DRIVES SOUTH THEN OFF SHORE AND CUTS OFF AND DRIFTS SLOWLY NORTH
LATE THIS WEEKEND EARLY NEXT WEEK THREATENING NEW ENGLAND WITH
SOME PRECIPITATION. MODELS HINTS THIS COULD TRANSITION FROM A
COLD CORE TO WARM CORE SYSTEM, BUT THAT REMAINS TO BE SEEN. AT
THIS POINT THE CONSENSUS KEEPS THE LOW WELL OFF SHORE AND AWAY
FROM BTV BUT CLOSE ENOUGH TO WATCH FOR SUNDAY NIGHT INTO MONDAY
NIGHT ESPECIALLY EASTERN NEW ENGLAND COASTAL AREAS.
THE OTHER WEATHER FEATURE WE ARE WATCHING IS A PACIFIC FRONT
MOVING EAST ACROSS THE COUNTRY BUT IT LOOKS LIKE IT WILL UNDERGO
FRONTOLYSIS AS IT MOVES INTO THE EASTERN RIDGE. SO LITTLE IN THE
WAY OF RAIN IS EXPECTED WITH THE FRONT AS IT DECAYS AND DRIES UP
MONDAY AND TUESDAY. CAN`T RULE OUT SOME LIGHT SHOWERS OR
SPRINKLES WITH LOW POPS. TEMPS WILL CONTINUE MILD BUT WITH LESS
SUNSHINE IT WONT BE QUITE AS WARM AS THE WEEKEND IN THE
AFTERNOONS AND NOT QUITE AS COOL IN THE MORNINGS. EXPECTING LOWS
IN THE 40S AND 50S AND HIGHS IN THE 60S TO NEAR 70.
IF NEITHER OF THESE WEATHER SYSTEMS GIVE US MEASURABLE RAIN, WE
MIGHT NOT SEE MUCH SIGNIFICANT RAIN RIGHT THROUGH NEXT WEEK WITH
MILD DRY WEATHER.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 12Z THURSDAY...MAINLY VFR EXCEPT LCL IFR/LIFR IN BR/FG AT
KMSS AND KSLK THROUGH 13Z AND AGAIN 07-13Z TONIGHT.
HIGH PRESSURE EDGING INTO NY AND NRLY FLOW OVER VT THIS MORNING
WITH LOW PRESSURE IN THE CANADIAN MARITIMES.
EXPECT FOG AT KMSS/KSLK TO BURN OFF BY 13Z.
VFR CONDITIONS EXPECTED WITH CU/SC FORMING MAINLY EAST OF BTV AND
ESPECIALLY MPV WHERE EXPECTING SCT-BKN CU THIS AFTERNOON.
WINDS WILL BE LIGHT AND VARIABLE OVER NY AND NORTHERLY 5 TO 10 KT
KPBG-KBTV-KMPV. COULD EVEN BE A FEW GUSTS INTO THE TEENS AT KMPV
WITH DEEP MIXING IN THE AFTERNOON.
CLEAR SKIES/CALM WINDS AGAIN TONIGHT, SO LOOKING FOR LCL VLIFR AT
KMPV KSLK FROM 07-13Z.
OUTLOOK 12Z THURSDAY THROUGH SUNDAY...MAINLY VFR WITH HIGH PRESSURE
BUILDING IN. BR/FG POSSIBLE 06-14Z EACH DAY ESP KSLK KMPV.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...KGM/TABER
NEAR TERM...KGM
SHORT TERM...KGM
LONG TERM...SISSON
AVIATION...SISSON
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
715 AM EDT WED SEP 25 2013
.SYNOPSIS...
SLOW MOVING LOW PRESSURE OVER THE CANADIAN MARITIMES WILL
CONTINUE TO FILTER IN MOISTURE FROM THE NORTH INTO VERMONT AND
PORTIONS OF NORTHERN NEW YORK...BRINGING PERIODS OF PARTLY CLOUDY
TO MOSTLY CLOUDY SKIES TODAY THROUGH FRIDAY. SURFACE HIGH
PRESSURE LOCATED OVER THE GREAT LAKES WILL SLOWLY BUILD TOWARD
THE NORTH COUNTRY WITH MOSTLY SUNNY SKIES AND TEMPERATURES
TRENDING WARMER INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 715 AM EDT WEDNESDAY...MINOR ADJUSTMENTS TO CURRENT
FCST...REFLECTING SATELLITE TRENDS...AS STRATUS DECK HAS
RETREATED FROM ALL BUT THE NEK. IR SATELLITE ALSO SHOWS AREA OF
MOISTURE SURGING MORE EWD UPSTREAM. RUC SHOWS CLOUDS FROM THIS
AREA MOVING INTO NORTH COUNTRY THIS AFTN...MORE SO THAN OTHER
MODELS...BUT SIMILAR IN TREND. HAVE INCREASED CLDS OVER NEK THIS
AFTN AND INTO THE ADKS. HAVE ALSO ADJUSTED TEMPS TO ACCOUNT FOR
COOLER TEMPS THIS MORNING.
PREVIOUS DISC...AT THE SFC...HIGH PRESSURE CONTINUES TO BUILD
OVER THE GREAT LAKES TODAY...WHILE THE VERTICALLY STACKED LOW
GRADUALLY PICKS UP A LITTLE MOMENTUM EWD LATE IN THE DAY INTO
TONIGHT. WITH THE CYCLONIC FLOW AROUND THIS LOW...SOME LOW CLOUDS
STILL EXPECTED...BUT SATELLITE IMAGERY SHOWS SHRINKING AREA OF
MOISTURE AS SUBSIDENCE OVER THE ERN GREAT LAKES SLOWLY SPREADS
EAST. EXPECT MOST OF THE AREA TO BE MOSTLY SUNNY THRU
MIDDAY...WITH EXCEPTION OF NEK. MODELS SHOW ANOTHER SURGE OF
LLVL/SHALLOW MOISTURE LATE THIS AFTN INTO OVERNIGHT. AREAS
EXPECTING TO STAY MORE ON THE SUNNY SIDE...SUCH AS SLV AND CT
VALLEY WILL SEE MAX TEMPS NEAR 70F IN THE SLV TO M/U 60S IN THE
CPV AND 50S- L60S IN NEK/MTNS.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH FRIDAY/...
AS OF 443 AM EDT WEDNESDAY...LITTLE CHANGE IN LARGE SCALE PATTERN
ANTICIPATED AS BLOCK FLOW ALOFT CONTINUES TONIGHT INTO THURSDAY.
WITH THE LOW TO OUR E CONTINUING TO FILTER IN LLVL
MOISTURE...CLOUDS WILL BE A TRICKY FCST...AS ALL GUIDANCE SHOWS
PLENTY OF MOISTURE TRAPPED BELOW THE TEMP INVERSION THRU
THURSDAY. LATE THURSDAY INTO FRIDAY WE FINALLY BREAK FREE OF
CYCLONIC FLOW FROM THE LOW PRESSURE SYSTEM AS IT SHIFTS MORE
EASTERLY. SFC HIGH PRESSURE WILL CREST OVER THE REGION ON FRIDAY
WITH CLEARING SKIES.
TEMPERATURES WILL BE NOTICEABLY WARMER IN AREAS THAT SEE THE MOST
SUN DURING THE DAY MAINLY IN THE SLV ON THURSDAY...WITH MAX TEMPS
AROUND 70F...U60S IN CPV AND L-M60S ELSEWHERE...WITH THE MTNS IN
THE 50S. TEMPS ALOFT TRENDING WARMER BY A DEGREE OR TWO EACH
DAY...THEREFORE THURS NT TEMPS WILL BE SIMILAR TO THAT OF
TONIGHT...AS WARMER TEMPS ALOFT WILL BE OFFSET BY DIMINISHING
CLOUDS. FRIDAY WILL BE THE WARMEST DAY WITH TEMPS NEARING 5
DEGREES ABOVE NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 401 AM EDT WEDNESDAY... MODELS GENERALLY IN GOOD AGREEMENT
THROUGH THE PERIOD LEADING TO DECENT FORECASTER CONFIDENCE FOR
FINE LEAF PEEPING WEATHER.
FRIDAY NIGHT INTO SUNDAY MASSIVE RIDGE ALONG AND HIGH PRESSURE AT
THE SURFACE WILL LEAD TO MAINLY CLEAR SKIES, COOL MORNINGS IN THE
30S AND 40S AND MILD AFTERNOONS IN THE UPPER 60S TO MID 70S.
THESE ARE LARGER THAN AVERAGE DIURNAL TEMP RANGES AND HAVE GONE
3-5 DEGREES LOWER THAN GUIDANCE FOR MINS ESPECIALLY ON SAT AND A
COUPLE DEGREES ON SUNDAY BUT HIGH TEMPS SEEM ABOUT RIGHT.
LOTS OF CONVECTION CURRENTLY OVER THE SOUTHEAST US AS UPPER TROF
DRIVES SOUTH THEN OFF SHORE AND CUTS OFF AND DRIFTS SLOWLY NORTH
LATE THIS WEEKEND EARLY NEXT WEEK THREATENING NEW ENGLAND WITH
SOME PRECIPITATION. MODELS HINTS THIS COULD TRANSITION FROM A
COLD CORE TO WARM CORE SYSTEM, BUT THAT REMAINS TO BE SEEN. AT
THIS POINT THE CONSENSUS KEEPS THE LOW WELL OFF SHORE AND AWAY
FROM BTV BUT CLOSE ENOUGH TO WATCH FOR SUNDAY NIGHT INTO MONDAY
NIGHT ESPECIALLY EASTERN NEW ENGLAND COASTAL AREAS.
THE OTHER WEATHER FEATURE WE ARE WATCHING IS A PACIFIC FRONT
MOVING EAST ACROSS THE COUNTRY BUT IT LOOKS LIKE IT WILL UNDERGO
FRONTOLYSIS AS IT MOVES INTO THE EASTERN RIDGE. SO LITTLE IN THE
WAY OF RAIN IS EXPECTED WITH THE FRONT AS IT DECAYS AND DRIES UP
MONDAY AND TUESDAY. CAN`T RULE OUT SOME LIGHT SHOWERS OR
SPRINKLES WITH LOW POPS. TEMPS WILL CONTINUE MILD BUT WITH LESS
SUNSHINE IT WONT BE QUITE AS WARM AS THE WEEKEND IN THE
AFTERNOONS AND NOT QUITE AS COOL IN THE MORNINGS. EXPECTING LOWS
IN THE 40S AND 50S AND HIGHS IN THE 60S TO NEAR 70.
IF NEITHER OF THESE WEATHER SYSTEMS GIVE US MEASURABLE RAIN, WE
MIGHT NOT SEE MUCH SIGNIFICANT RAIN RIGHT THROUGH NEXT WEEK WITH
MILD DRY WEATHER.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 06Z THURSDAY...MAINLY VFR EXCEPT LCL IFR/LIFR IN BR/FG AT
KMSS AND KSLK THROUGH 12Z.
HIGH PRESSURE EDGING INTO NY AND NRLY FLOW OVER VT THIS MORNING
WITH LOW PRESSURE IN THE CANADIAN MARITIMES.
EXPECT FOG AT KMSS/KSLK TO BURN OFF BY 12Z.
VFR CONDITIONS EXPECTED WITH CU/SC FORMING MAINLY EAST OF BTV AND
ESPECIALLY MPV WHERE EXPECTING AT LEAST BKN CU THIS AFTERNOON.
WINDS WILL BE LIGHT AND VARIABLE OVER NY AND NORTHERLY 5 TO 10 KT
KPBG-KBTV-KMPV. COULD EVEN BE A FEW GUSTS INTO THE TEENS AT KMPV
WITH DEEP MIXING IN THE AFTERNOON.
OUTLOOK 06Z THURSDAY THROUGH SUNDAY...MAINLY VFR WITH HIGH
PRESSURE BUILDING IN. BR/FG POSSIBLE 06-14Z EACH DAY ESP KSLK KMPV.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...KGM/TABER
NEAR TERM...KGM
SHORT TERM...KGM
LONG TERM...SISSON
AVIATION...SISSON
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1002 AM MDT WED SEP 25 2013
.UPDATE...
&&
.SHORT TERM...ONGOING FORECASTS LOOK GOOD. UPPER RIDGE TO MOVE
EAST INTO CENTRAL PLAINS AS UPPER TROUGH DEEPENS OVER THE PACIFIC
NORTHWEST. SOUTHWEST FLOW ALOFT WILL BE ON THE INCREASE...WITH
ENOUGH MIXING ACROSS THE PLAINS FOR GUSTY WINDS AT TIMES.
TEMPERATURE AND THICKNESS PROGS SUPPORT HIGHS IN THE LOWER TO
MIDDLE 80S ACROSS THE PLAINS. SOME INCREASE IN HIGH LEVEL CLOUDS
LATER THIS AFTERNOON AND EVENING.
.AVIATION...CURRENT TAF TRENDS STILL ON TRACK. WEAK SOUTHEAST
WINDS TO SHIFT TO THE SOUTHWEST AROUND 20Z AND INCREASE. LATEST
RAP AND HRRR SUGGEST THE DEVELOPMENT OF A DENVER CYCLONE OVER
SOUTHERN WELD COUNTY IN THE 20-22Z TIME FRAME WHICH MAY PROVIDE
MORE OF A NORTHWEST COMPONENT AT BJC. WILL WAIT AND SEE WHAT
DEVELOPS IN THE NEXT FEW HOURS.
&&
.HYDROLOGY...MOST RIVER AND STREAM LEVELS HAVE FLATTENED OUT OR
RECEDED DURING THE PAST FEW HOURS. HOWEVER LEVELS ALONG THE SOUTH
PLATTE RIVER FROM MORGAN COUNTY THROUGH SEDGWICK COUNTY SHOWN SOME
SLIGHT RISES...IN PARTICULAR NEAR WELDONA AND NEAR JULESBURG.
DESPITE THE SLIGHT RISES...MAJOR FLOODING ISSUES ARE NOT EXPECTED.
DRY WEATHER TO CONTINUE FOR THE NEXT 24 TO 36 HOURS.
&&
.PREV DISCUSSION... /ISSUED 326 AM MDT WED SEP 25 2013/
SHORT TERM...THE HIGH PRESSURE RIDGE ALOFT IS SHIFTING EAST INTO
THE CENTRAL PLAINS TODAY. THIS WILL LEAD TO A STRONGER SOUTHWEST
FLOW ALOFT OVER COLORADO AS THE UPPER TROF DEEPENS ALONG THE
PACIFIC NORTHWEST COAST. THIS WILL LEAD TO CONTINUED WARMING
TEMPERATURES TODAY AND GUSTY SOUTHWEST WINDS IN THE MOUNTAINS AND
PLAINS. TEMPERATURES WILL BE ANOTHER 10 DEGREES WARMER WITH
READINGS IN THE LOWER TO MID 80S OVER LOWER ELEVATIONS AND 50S AND
60S IN THE MOUNTAINS. DESPITE THE APPROACHING TROF...AIRMASS IS
TOO DRY TO SUPPORT ANY STORMS OR SHOWERS OVER CWA. PRECIPITABLE
WATER VALUES WILL LIKELY REMAIN UNDER FOUR TENTHS OF AN INCH.
LONG TERM...SOUTHWEST FLOW WILL CONTINUE ACROSS THE STATE AS THE
RIDGE AXIS MOVES FURTHER INTO THE CENTRAL PLAINS AND THE UPPER
TROUGH MOVES CLOSER TO THE AREA. SOME CLOUD COVER AND SLIGHTLY
COOLER MID LEVEL TEMPERATURES WILL ALLOW TEMPERATURES TO COOL DOWN
FROM TODAY`S READINGS BY ABOUT 5 DEGREES. THE SURFACE LOW OVER THE
CO/NE/KS BORDERS WILL CONTINUE THE GUSTY SOUTH TO SOUTHWEST
SURFACE WINDS ACROSS THE AREA. NORTHEASTERN AND NORTH CENTRAL CO
WILL REMAIN DRY IN THE MORNING AND AFTERNOON...BUT THEN AS THE
TROUGH GETS CLOSER THERE MAY BE A SLIGHT CHANCE FOR SOME SHOWERS
IN THE MOUNTAINS...ALTHOUGH THIS DOES LOOK WITH EACH NEW COMPUTER
MODEL RUN TO STAY WEST. THE SURFACE LOW OUT OVER THE NORTHEAST
PLAINS MAY PROVIDE ENOUGH CONVERGENCE FOR AN ISOLATED
SHOWER...HAVE 10 PERCENT CHANCE OUT THERE. MAY SEE ONE GROW
STRONGER INTO A STORM...BUT WILL LEAVE THAT OUT FOR NOW AS THE
MODELS ARE STILL TRYING TO DECIDE ON THE SPEED OF THIS SYSTEM.
THE COLD FRONT ASSOCIATED WITH THIS TROUGH IS EXPECTED TO MOVE
SOUTH THROUGH THE STATE JUST AFTER MIDNIGHT AND INTO FRIDAY
MORNING. RAIN AND SNOW SHOWERS WILL BE INCREASING NORTHWEST TO
SOUTHEAST ACROSS THE FORECAST AREA THROUGH THE DAY FRIDAY. THIS
SYSTEM WILL BE COLDER THAN LAST SUNDAYS SYSTEM...EXPECTING SNOW
LEVELS TO BE DROPPING DOWN TO AROUND 8000 FT BY FRIDAY NIGHT. MAX
TEMPERATURES WILL STRUGGLE FRIDAY TO GET ABOVE 60 DEGREES OVER THE
PLAINS AND WILL BE IN THE 40S FOR THE MOUNTAINS. THE MOISTURE
LOOKS TO CONTINUE HEADING SOUTH AND EAST FRIDAY NIGHT THAT THE
SNOW AND RAIN SHOULD BE DONE BY SUNRISE SATURDAY MORNING. ALL IN
ALL....SNOW AMOUNTS FOR THE FOOTHILLS LOOK TO BE LIGHT...WITH
THE HIGHER MOUNTAINS SEEING 2-4 INCHES. TEMPERATURES FRIDAY NIGHT
WILL DIP DOWN INTO THE UPPER 30S AND LOW 40S FOR THE PLAINS AND
DOWN INTO THE 20S FOR THE MOUNTAINS.
SATURDAY THROUGH TUESDAY...THE FLOW ALOFT BECOMES MORE ZONAL WITH
SLIGHT RIDGING AND KEEPS MOST ENERGY UP TO THE NORTH OF THE
STATE. THEREFORE EXPECT A SLOW WARMING TREND AND DRY WEATHER.
SATURDAY WILL HAVE LITTLE WARMING IN THE WAKE OF THE COLD FRONT
THEN EXPECT NEAR NORMAL TEMPERATURES BY SUNDAY.
AVIATION...VFR WITH SOME MIDDLE AND HIGH LEVEL SCATTERED CLOUDS
TODAY. MAIN ISSUE WILL BE INCREASING GUSTY SOUTHWEST WINDS BETWEEN
18-20Z. MAY SEE SOME GUSTS IN THE 20-30KT RANGE AT APA/DEN AS
STRONGER MID LEVEL WINDS MIX DOWN TO THE SURFACE. MAY BUMP UP
WIND SPEES A BIT IN NEXT 12Z ISSUANCE.
HYDROLOGY...RIVER AND STREAM LEVELS WILL CONTINUE TO BE FLAT OR
RECEDED SOME OVER THE FRONT RANGE...WHILE LEVELS ON THE SOUTH
PLATTE FROM MORGAN COUNTY OUT THROUGH SEDGWICK COUNTY MAY STILL
SEE SOME SLIGHT RISES FROM RAINFALL FROM MONDAY`S RAINFALL. SOUTH
PLATTE NEAR WELDONA AND NEAR JULESBURG HAVE SHOWN SOME SLIGHT
RISES IN THE PAST 6 HOURS BUT NOT EXPECTED TO RESULT IN ANY MAJOR
FLOODING ISSUES. DRY WEATHER CONDITIONS STILL EXPECTED FOR NEXT 36
HOURS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...HYDROLOGIC ADVISORY CONTINUES
FOR LOGAN COUNTY UNTIL 215 PM MDT TODAY...
&&
$$
SHORT TERM...D-L
LONG TERM....KRIEDERMAN
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS JACKSON KY
236 PM EDT WED SEP 25 2013
.UPDATE...
ISSUED AT 116 PM EDT WED SEP 25 2013
UPDATED FOR OBSERVED CONDITIONS TO BLEND INTO THE LATE AFTERNOON
FORECAST. THERE WAS LITTLE CHANGE TO THE OVERALL FORECAST.
UPDATE ISSUED AT 1052 AM EDT WED SEP 25 2013
SHOWERS WHICH AFFECTED MOST PLACES FROM KJKL SOUTH WERE LARGELY ON
THE WAY OUT LATE THIS MORNING. 12Z NAM AND LATEST HRRR STILL GENERATE
MORE CONVECTION DURING THE AFTERNOON...ESPECIALLY OVER THE SOUTHERN
PART OF THE AREA. HAVE UPDATED POPS FOR THE REMAINDER OF THE
DAY...WITH THE MAIN CHANGE BEING A DROP BACK TO NOTHING MORE THAN
LIKELY POPS FOR MOST PLACES IN THE SOUTH. HAVE LEFT A SLIGHT CHANCE
OF THUNDER IN FOR THE SOUTH...BUT EXPECTED INSTABILITY REALLY LOOKS
MEAGER.
UPDATE ISSUED AT 755 AM EDT WED SEP 25 2013
DID A QUICK GRID UPDATE TO FINE TUNE POPS THROUGH THE NEXT SEVERAL
HOURS BASED ON THE LATEST RADAR TRENDS AND HRRR/RAP13. ALSO TWEAKED
T/TD GRIDS PER THE LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE
NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 400 AM EDT WED SEP 25 2013
07Z SFC ANALYSIS SHOWS A BROAD AREA OF WEAK LOW PRESSURE MOVING
THROUGH THE TENNESSEE VALLEY AND PUSHING INTO SOUTHEAST KENTUCKY.
THIS IS BRINGING A BATCH OF NUMEROUS TO SCATTERED SHOWERS TO THE
CUMBERLAND VALLEY EARLY THIS MORNING. A FEW LIGHTNING STRIKES
ASSOCIATED WITH THIS AREA EARLIER IN THE NIGHT HAVE ENDED FOR NOW.
LOW AND MID LEVEL CLOUDS CURRENTLY COVER EAST KENTUCKY AND THESE ARE
HELPING TO KEEP ANY FOG AT BAY. THESE CLOUDS ARE ALSO SUPPORTING
MILDER TEMPS OVERNIGHT WITH READINGS VARYING FROM THE UPPER 50S IN
THE NORTHEAST TO MID AND UPPER 60S IN THE SOUTHWEST. MEANWHILE...
WINDS ARE LIGHT THROUGH THE CWA AND DEW POINTS VARY FROM THE UPPER 50S
IN THE NORTH TO THE MID 6OS IN THE SOUTH.
THE MODELS HAVE SETTLED ON A SOLUTION ALOFT FOR THE SHORT TERM THAT
CONSISTS OF A BROAD TROUGH CROSSING INTO THE OHIO VALLEY EARLY THIS
MORNING AND ROLLING EAST ACROSS THE SPINE OF THE CENTRAL APPALACHIANS
BY THURSDAY MORNING. RIDGING EVENTUALLY FOLLOWS THIS FOR THURSDAY
EVENING...BUT NOT BEFORE CYCLONIC MID LEVEL FLOW DEPARTS LATE
THURSDAY AFTERNOON. WHILE THE MODELS ARE IN PRETTY GOOD AGREEMENT
WITH THIS EVOLUTION...THERE REMAINS SOME SUBSTANTIAL QPF DIFFERENCES
THROUGH THE CWA TODAY AND CONSISTENCY WITH THIS AND OTHER SENSIBLE
PARAMETERS HAVE BEEN BELOW AVERAGE WITH THIS SYSTEM. ACCORDINGLY...
HAVE FOLLOWED THE LATEST HRRR...NAM12...AND ECMWF MOST CLOSELY FOR WX
SPECIFICS THROUGH THE SHORT TERM.
SENSIBLE WEATHER WILL FEATURE SHOWERS AND EVENTUALLY EMBEDDED
THUNDERSTORMS MOVING INTO EAST KENTUCKY FROM WEST TO EAST...MAINLY
TARGETING THE SOUTHERN HALF OF THE CWA. THAT SAID...THE LATEST HRRR
AND RAP13 DEPICT THE HIGHER POPS AND BETTER QPF A BIT FARTHER NORTH
TODAY THAN THE NAM12 AND ECMWF SUGGEST. FOR THAT REASON HAVE LIFTED
THE HIGHER POPS AND SOME QPF A BIT NORTH OF MODEL CONSENSUS. POCKETS
OF HEAVIER RAIN FROM LONGER DURATION SHOWERS...AND A POTENTIAL FOR
TRAINING...WILL LIKELY LEAVE BEHIND UP TO AN INCH OF RAIN IN SOME
PLACES THROUGHOUT THE CUMBERLAND VALLEY. WILL ADD THIS MENTION TO
THE HWO. THE SYSTEM PULLS AWAY TONIGHT AND ENDS ALL BUT AN ISOLATED
SHOWER PCPN THREAT FOR THE AREA DURING THE EVENING. LOW CLOUDS WILL
BREAK UP DURING THE MORNING ON THURSDAY WITH GOOD AMOUNTS OF SUNSHINE
RETURNING BY AFTERNOON. IN THE FAR EAST...CLOUDS WILL LINGER LONGER
ALONG WITH A SMALL THREAT FOR A SHOWER IN THE MORNING.
USED THE CONSSHORT AND ITS BC VERSION TO INITIATE THE TD AND WIND
GRIDS THROUGH 00Z THURSDAY...THEN THE BC/CONSALL THEREAFTER. FOR
TEMPERATURES...USED THE CONSSHORT THROUGH MID MORNING BLENDED WITH A
DIURNAL CURVE BASED ON THE NAM12 AFTER SLIGHTLY MODIFYING THE
CONSALL MAX AND MIN TEMPS. AS FOR POPS...ENDED UP A TAD CLOSER TO
THE HIGHER MET NUMBERS THROUGH TONIGHT AND THEN WENT MAINLY DRY ON
THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 234 AM EDT WED SEP 25 2013
AS A WEAK AREA OF LOW PRESSURE CROSS SOUTHEAST KENTUCKY...SHOWERS
WILL CONTINUE TO OVERSPREAD THE CUMBERLAND VALLEY THIS MORNING WITH
ISOLATED THUNDERSTORMS POSSIBLE. THIS SYSTEM WILL DRAG THROUGH THE
LOWER HALF OF EAST KENTUCKY TODAY AND BRING A BETTER CHANCE OF
THUNDER TO THE TAF SITES FROM LATE MORNING INTO THE AFTERNOON. THE
HEAVIER SHOWERS ASSOCIATED WITH THIS PASSAGE SHOULD BE ENOUGH TO
LOWER CIGS AND VIS DOWN TO MVFR...AND PROBABLY BRIEFLY IFR...THROUGH
THE AFTERNOON. THE SHOWERS WILL LIKELY END FROM NORTHWEST TO
SOUTHEAST LATER THIS EVENING AS VFR CIGS AND VIS RETURN. WINDS WILL
REMAIN LIGHT AND VARIABLE THROUGH THE TAF PERIOD...EXCEPT IN THE
IMMEDIATE VICINITY OF ANY STRAY STORM.A STRONG RIDGE OF HIGH PRESSURE
WILL BUILD OVER THE AREA FROM THURSDAY NIGHT THROUGH SATURDAY
PROVIDING A DRY AND PLEASANT STRETCH OF WEATHER. THE NEXT CHANCE OF
RAIN WILL HOLD OFF UNTIL LATE SUNDAY AND SUNDAY NIGHT AS A FAST
MOVING SHORTWAVE PUSHES A COLD FRONT ACROSS KENTUCKY. MODELS STILL
DIFFER ON TIMING AND STRENGTH OF THIS SYSTEM...BUT OVERALL...THIS
FEATURE HAS LOOKED WEAKER AND WEAKER OVER THE PAST FEW DAYS WITH THE
FORCING ALMOST NON-EXISTENT. THUS...ONLY GOING TO CARRY SLIGHT CHANCE
POPS WITH THIS BOUNDARY AS IT PUSHES ACROSS THE AREA LATE IN THE
WEEKEND. THE ECMWF HOLDS THE FRONT UP NEAR THE AREA ON
MONDAY...PERHAPS ALLOWING FOR A FEW SHOWERS INTO MONDAY AFTERNOON.
HOWEVER...THE TENDENCY IS TO DRY THINGS OUT FROM MONDAY NIGHT INTO
THE MIDDLE OF NEXT WEEK. A GOOD CHANCE MOST OF THE EXTENDED WILL
REMAIN DRY FOR MOST OF THE AREA. TEMPERATURES WILL TREND SLIGHTLY
ABOVE NORMAL FOR THE END OF THE WEEK INTO SATURDAY...BEFORE A SLIGHT
DIP FOR SUNDAY AND MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 236 PM EDT WED SEP 25 2013
CONDITIONS WERE MAINLY VFR AT THE START OF THE PERIOD...WITH ISOLATED
IFR. THERE WERE SCATTERED SHOWERS AND VERY ISOLATED THUNDERSTORMS
OVER ALL BUT THE FAR NORTHERN PART OF THE AREA. THE SHOWERS AND
THUNDERSTORMS WILL PEAK IN COVERAGE LATE THIS AFTERNOON...AND THEN BE
ON THE DECLINE WITH MOST OF THEM DYING OUT BY 02Z. CLOUDS WILL THIN
OUT THIS EVENING...WHICH WILL ALLOW FOG TO DEVELOP. MOST PLACES
SHOULD DROP TO IFR BETWEEN 04Z AND 10Z...WITH GRADUAL IMPROVEMENT TO
VFR BEGINNING AFTER SUNRISE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
116 PM EDT WED SEP 25 2013
.UPDATE...
ISSUED AT 116 PM EDT WED SEP 25 2013
UPDATED FOR OBSERVED CONDITIONS TO BLEND INTO THE LATE AFTERNOON
FORECAST. THERE WAS LITTLE CHANGE TO THE OVERALL FORECAST.
UPDATE ISSUED AT 1052 AM EDT WED SEP 25 2013
SHOWERS WHICH AFFECTED MOST PLACES FROM KJKL SOUTH WERE LARGELY ON
THE WAY OUT LATE THIS MORNING. 12Z NAM AND LATEST HRRR STILL GENERATE
MORE CONVECTION DURING THE AFTERNOON...ESPECIALLY OVER THE SOUTHERN
PART OF THE AREA. HAVE UPDATED POPS FOR THE REMAINDER OF THE
DAY...WITH THE MAIN CHANGE BEING A DROP BACK TO NOTHING MORE THAN
LIKELY POPS FOR MOST PLACES IN THE SOUTH. HAVE LEFT A SLIGHT CHANCE
OF THUNDER IN FOR THE SOUTH...BUT EXPECTED INSTABILITY REALLY LOOKS
MEAGER.
UPDATE ISSUED AT 755 AM EDT WED SEP 25 2013
DID A QUICK GRID UPDATE TO FINE TUNE POPS THROUGH THE NEXT SEVERAL
HOURS BASED ON THE LATEST RADAR TRENDS AND HRRR/RAP13. ALSO TWEAKED
T/TD GRIDS PER THE LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE
NDFD AND WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 400 AM EDT WED SEP 25 2013
07Z SFC ANALYSIS SHOWS A BROAD AREA OF WEAK LOW PRESSURE MOVING
THROUGH THE TENNESSEE VALLEY AND PUSHING INTO SOUTHEAST KENTUCKY.
THIS IS BRINGING A BATCH OF NUMEROUS TO SCATTERED SHOWERS TO THE
CUMBERLAND VALLEY EARLY THIS MORNING. A FEW LIGHTNING STRIKES
ASSOCIATED WITH THIS AREA EARLIER IN THE NIGHT HAVE ENDED FOR NOW.
LOW AND MID LEVEL CLOUDS CURRENTLY COVER EAST KENTUCKY AND THESE ARE
HELPING TO KEEP ANY FOG AT BAY. THESE CLOUDS ARE ALSO SUPPORTING
MILDER TEMPS OVERNIGHT WITH READINGS VARYING FROM THE UPPER 50S IN
THE NORTHEAST TO MID AND UPPER 60S IN THE SOUTHWEST. MEANWHILE...
WINDS ARE LIGHT THROUGH THE CWA AND DEW POINTS VARY FROM THE UPPER 50S
IN THE NORTH TO THE MID 6OS IN THE SOUTH.
THE MODELS HAVE SETTLED ON A SOLUTION ALOFT FOR THE SHORT TERM THAT
CONSISTS OF A BROAD TROUGH CROSSING INTO THE OHIO VALLEY EARLY THIS
MORNING AND ROLLING EAST ACROSS THE SPINE OF THE CENTRAL APPALACHIANS
BY THURSDAY MORNING. RIDGING EVENTUALLY FOLLOWS THIS FOR THURSDAY
EVENING...BUT NOT BEFORE CYCLONIC MID LEVEL FLOW DEPARTS LATE
THURSDAY AFTERNOON. WHILE THE MODELS ARE IN PRETTY GOOD AGREEMENT
WITH THIS EVOLUTION...THERE REMAINS SOME SUBSTANTIAL QPF DIFFERENCES
THROUGH THE CWA TODAY AND CONSISTENCY WITH THIS AND OTHER SENSIBLE
PARAMETERS HAVE BEEN BELOW AVERAGE WITH THIS SYSTEM. ACCORDINGLY...
HAVE FOLLOWED THE LATEST HRRR...NAM12...AND ECMWF MOST CLOSELY FOR WX
SPECIFICS THROUGH THE SHORT TERM.
SENSIBLE WEATHER WILL FEATURE SHOWERS AND EVENTUALLY EMBEDDED
THUNDERSTORMS MOVING INTO EAST KENTUCKY FROM WEST TO EAST...MAINLY
TARGETING THE SOUTHERN HALF OF THE CWA. THAT SAID...THE LATEST HRRR
AND RAP13 DEPICT THE HIGHER POPS AND BETTER QPF A BIT FARTHER NORTH
TODAY THAN THE NAM12 AND ECMWF SUGGEST. FOR THAT REASON HAVE LIFTED
THE HIGHER POPS AND SOME QPF A BIT NORTH OF MODEL CONSENSUS. POCKETS
OF HEAVIER RAIN FROM LONGER DURATION SHOWERS...AND A POTENTIAL FOR
TRAINING...WILL LIKELY LEAVE BEHIND UP TO AN INCH OF RAIN IN SOME
PLACES THROUGHOUT THE CUMBERLAND VALLEY. WILL ADD THIS MENTION TO
THE HWO. THE SYSTEM PULLS AWAY TONIGHT AND ENDS ALL BUT AN ISOLATED
SHOWER PCPN THREAT FOR THE AREA DURING THE EVENING. LOW CLOUDS WILL
BREAK UP DURING THE MORNING ON THURSDAY WITH GOOD AMOUNTS OF SUNSHINE
RETURNING BY AFTERNOON. IN THE FAR EAST...CLOUDS WILL LINGER LONGER
ALONG WITH A SMALL THREAT FOR A SHOWER IN THE MORNING.
USED THE CONSSHORT AND ITS BC VERSION TO INITIATE THE TD AND WIND
GRIDS THROUGH 00Z THURSDAY...THEN THE BC/CONSALL THEREAFTER. FOR
TEMPERATURES...USED THE CONSSHORT THROUGH MID MORNING BLENDED WITH A
DIURNAL CURVE BASED ON THE NAM12 AFTER SLIGHTLY MODIFYING THE
CONSALL MAX AND MIN TEMPS. AS FOR POPS...ENDED UP A TAD CLOSER TO
THE HIGHER MET NUMBERS THROUGH TONIGHT AND THEN WENT MAINLY DRY ON
THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 234 AM EDT WED SEP 25 2013
A STRONG RIDGE OF HIGH PRESSURE WILL BUILD OVER THE AREA FROM
THURSDAY NIGHT THROUGH SATURDAY PROVIDING A DRY AND PLEASANT STRETCH
OF WEATHER. THE NEXT CHANCE OF RAIN WILL HOLD OFF UNTIL LATE SUNDAY
AND SUNDAY NIGHT AS A FAST MOVING SHORTWAVE PUSHES A COLD FRONT
ACROSS KENTUCKY. MODELS STILL DIFFER ON TIMING AND STRENGTH OF THIS
SYSTEM...BUT OVERALL...THIS FEATURE HAS LOOKED WEAKER AND WEAKER
OVER THE PAST FEW DAYS WITH THE FORCING ALMOST NON-EXISTENT.
THUS...ONLY GOING TO CARRY SLIGHT CHANCE POPS WITH THIS BOUNDARY AS
IT PUSHES ACROSS THE AREA LATE IN THE WEEKEND. THE ECMWF HOLDS THE
FRONT UP NEAR THE AREA ON MONDAY...PERHAPS ALLOWING FOR A FEW
SHOWERS INTO MONDAY AFTERNOON. HOWEVER...THE TENDENCY IS TO DRY
THINGS OUT FROM MONDAY NIGHT INTO THE MIDDLE OF NEXT WEEK. A GOOD
CHANCE MOST OF THE EXTENDED WILL REMAIN DRY FOR MOST OF THE AREA.
TEMPERATURES WILL TREND SLIGHTLY ABOVE NORMAL FOR THE END OF THE
WEEK INTO SATURDAY...BEFORE A SLIGHT DIP FOR SUNDAY AND MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 805 AM EDT WED SEP 25 2013
AS A WEAK AREA OF LOW PRESSURE CROSS SOUTHEAST KENTUCKY...SHOWERS
WILL CONTINUE TO OVERSPREAD THE CUMBERLAND VALLEY THIS MORNING WITH
ISOLATED THUNDERSTORMS POSSIBLE. THIS SYSTEM WILL DRAG THROUGH THE
LOWER HALF OF EAST KENTUCKY TODAY AND BRING A BETTER CHANCE OF
THUNDER TO THE TAF SITES FROM LATE MORNING INTO THE AFTERNOON. THE
HEAVIER SHOWERS ASSOCIATED WITH THIS PASSAGE SHOULD BE ENOUGH TO
LOWER CIGS AND VIS DOWN TO MVFR...AND PROBABLY BRIEFLY IFR...THROUGH
THE AFTERNOON. THE SHOWERS WILL LIKELY END FROM NORTHWEST TO
SOUTHEAST LATER THIS EVENING AS VFR CIGS AND VIS RETURN. WINDS WILL
REMAIN LIGHT AND VARIABLE THROUGH THE TAF PERIOD...EXCEPT IN THE
IMMEDIATE VICINITY OF ANY STRAY STORM.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS DULUTH MN
341 PM CDT WED SEP 25 2013
.SYNOPSIS...
ISSUED AT 328 PM CDT WED SEP 25 2013
LAKE SUPERIOR DOMINATED BY LOW STRATUS/FOG LAYER WHILE INLAND
AREAS ARE SUNNY UNDER A DRY AIR MASS AND HIGH PRESSURE. MAJOR
UPPER TROF OVER INTERMOUNTAIN WEST IS AMPLIFYING COURTESY OF 140KT
UPPER JET ON SWRN FLANK OF CIRCULATION. A SWRLY MID LVL FLOW IS
CURRENTLY IN PLACE ACROSS THE CWA. AN AREA OF MID CLOUDS
ASSOCIATED WITH A WEAK SHORTWAVE FEATURE ALOFT IS MOVING INTO THE
WRN CWA. WARM ADVECTION REGIME CONTINUES TO INCREASE OVER THE CWA
AS CYCLOGENESIS IS UNDERWAY OVER WRN HI PLAINS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 328 PM CDT WED SEP 25 2013
TONIGHT...EXPECT AREA OF CLOUDS/FOG OVER LAKE SUPERIOR TO ADVECT
INLAND AS SFC HEATING DECREASES. LATEST HRRR 3KM SHOWS HIGHEST PROB
OF LOWEST VIS ALONG NSHORE...TWIN PORTS...AND CHEQUAMEGON BAY.WILL
ISSUE A DENSE FOG ADVISORY CONSIDERING THE PRESENCE OF THE DENSE
FOG OVER THE LAKE AND ITS LIKELY PENETRATION INLAND. LATEST HI-RES
MDLS SUGGEST FOG BANK MAY TRY TO SHIFT FARTHER NORTH AND WEST
OVERNIGHT. ELSEWHERE WILL USE PATCHY FOG FOR POTENTIAL OF LIGHT
WINDS/SATURATION IN NEAR SFC LAYER.
TOMORROW...DENSE FOG EXPECTED TO PERSIST NEAR LAKE SUPERIOR
THROUGH EARLY MORNING. MAIN ISSUE TOMORROW WILL BE INCREASE IN
GUSTY SE WINDS. LATEST BUFKIT MOMENTUM PROFILES INDICATE GUSTS TO
35 AND POSSIBLY AN ISOLATED 40 MPH ARE POSSIBLE OVER NE MN ZONES BY
AFTN.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 328 PM CDT WED SEP 25 2013
ON THURSDAY NIGHT...A SHARP UPPER LEVEL RIDGE WILL EXTEND THROUGH
THE CENTRAL PLAINS...INTO THE JAMES BAY AREA NEAR HUDSON BAY.
MEANWHILE...A LONGWAVE TROUGH WILL BE LOCATED IN THE FAR
SOUTHWESTERN UNITED STATES. IN BETWEEN WE WILL BE IN SW FLOW. THE
MODELS ARE HINTING AT A LOW PRESSURE SYSTEM DEVELOPING IN THE HIGH
PLAINS THURSDAY NIGHT AND FRIDAY...WITH A FRONT OR SURFACE TROUGH
EXTENDING NORTHEASTWARD INTO MINNESOTA. QPF AMOUNTS VARY...BUT THE
GENERAL CONSENSUS IS THAT THERE WILL BE SOME LIGHT PRECIPITATION
ACROSS THE MN SIDE OF OUR CWA. THE LONGWAVE TROUGH EDGES EASTWARD ON
FRIDAY...BRINGING A POTENTIALLY MORE SUBSTANTIAL CHANCE OF
PRECIPITATION TO THE CWA. THE BEST CHANCE OF RAIN AND EMBEDDED
THUNDERSTORMS WOULD BE IN THE MN SIDE ONCE AGAIN. A SHORTWAVE AND
UPPER LEVEL VORT MAX WILL LIFT INTO THE UPPER RED RIVER VALLEY AND
WESTERN GREAT LAKES REGION FRIDAY NIGHT AND SATURDAY...BRINGING A
WET PERIOD TO THE WESTERN GREAT LAKES FRIDAY NIGHT AND SATURDAY. THE
GFS IS FASTEST AT PUSHING THE SYSTEM OUT OF THE AREA ON
SATURDAY...WITH THE GEM AND ECMWF BEING SLOWER. WILL USE A BLEND OF
THE ABOVE MODELS FOR THE MOST PART. BY SUNDAY...A MORE ZONAL FLOW
ESTABLISHES ITSELF ACROSS THE NORTH CENTRAL UNITED STATES. SUNDAY
INTO TUESDAY LOOKS LIKE IT WILL BE GENERALLY DRY ACROSS THE
REGION...WITH A CHANCE OF SHOWERS IN ONLY A FEW LOCATIONS THROUGH
WEDNESDAY AS WELL. TEMPERATURES WILL GENERALLY BE ABOVE NORMAL WITH
HIGHS IN THE 60S AND EVEN SOME LOWER TO MIDDLE 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1255 PM CDT WED SEP 25 2013
THE LOW CLOUDS AND FOG HAVE CLEARED OFF FOR ALL OF THE TAF
SITES...BUT A LARGE AREA OF STRATUS AND FOG REMAINED ACROSS LAKE
SUPERIOR EARLY THIS AFTERNOON. THE HIGH RESOLUTION MODELS INDICATE
THE LOW CLOUDS AND FOG WILL AGAIN STREAM INTO THE INTERIOR AREAS
OF THE ARROWHEAD DURING THE EVENING...BECOMING DENSE ONCE AGAIN.
HAVE HIT FOG HARD FOR THE NIGHT AND EARLY ON THURSDAY. THINK THE
MAJORITY OF SITES WILL NOT SEE THE DENSE FOG BUT MORE PATCHY FOG.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 49 72 56 75 / 0 0 10 10
INL 50 75 57 69 / 0 0 10 70
BRD 53 81 61 72 / 0 0 10 40
HYR 46 74 57 79 / 0 0 0 10
ASX 46 72 57 78 / 0 0 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY FROM 7 PM THIS EVENING TO 9 AM CDT THURSDAY
FOR MNZ020-021-037.
WI...DENSE FOG ADVISORY FROM 7 PM THIS EVENING TO 9 AM CDT THURSDAY
FOR WIZ001>004.
LS...DENSE FOG ADVISORY UNTIL NOON CDT THURSDAY FOR LSZ121-140>148.
&&
$$
SYNOPSIS...CANNON
SHORT TERM...CANNON
LONG TERM...DAP
AVIATION...DAP
AREA FORECAST DISCUSSION
NWS DULUTH MN
1258 PM CDT WED SEP 25 2013
.UPDATE...
ISSUED AT 1255 PM CDT WED SEP 25 2013
UPDATE FOR NEW AVIATION DISCUSSION BELOW.
UPDATE ISSUED AT 1018 AM CDT WED SEP 25 2013
MAIN FOCUS IN SHORT TERM IS EXTENSION OF FOG/STRATUS DECK
EXTENDING FROM LAKE SUPERIOR INLAND TO SRN CARLTON COUNTY. HI RES
MDL SFC COND PRESS DEFICITS SEEM TO REASONABLY HANDLE THE FEATURE
. SHOULD HAVE A PERIOD OF CLEARING/IMPROVEMENT THIS AFTN BEFORE
REDEVELOPMENT INLAND AGAIN THIS EVENING. HRRR 3KM/DLHWRF SHOWS
INCREASING NE WIND INTO HEAD OF LAKE LATER TODAY WHICH MAY PUSH
STRATUS/FG INLAND SOONER THAN CURRENTLY FCST. HAVE ADJUSTED SKY/WX
GRIDS TO ACCOUNT FOR STRATUS/FG. ALTHOUGH WARMING HAS BEEN DELAYED...FCST
MAX TEMPS HAVE AN OPPORTUNITY TO REACH INTO 60S NEAR LAKE.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY AFTERNOON)
ISSUED AT 322 AM CDT WED SEP 25 2013
MAIN CONCERNS IN THE SHORT TERM ARE FOCUSED AROUND THE AREAS OF
FOG THIS MORNING...WITH LOCALLY DENSE CONDITIONS THROUGH 9
AM...AND GUSTY SOUTH WINDS THIS AFTERNOON...AND AGAIN THURSDAY
AFTERNOON. TEMPERATURES AROUND THE TWIN PORTS AND THE PERIPHERY OF
LAKE SUPERIOR WILL ALSO BE AN AREA OF ATTENTION IN THE SHORT TERM.
HIGH PRESSURE AT THE SURFACE OVER THE GREAT LAKES AND UPPER LEVEL
RIDGING ACROSS THE UPPER MIDWEST WILL KEEP CONDITIONS VERY QUIET
IN THE SHORT TERM...THROUGH THURSDAY AFTERNOON. WEAK WAA IN THE
MID/LOW LEVELS THIS MORNING HAS ALLOWED A SHARP INVERSION TO FORM
AND...COMBINED WITH LIGHT/CALM WINDS AND A SHALLOW MOIST LAYER TO
PRODUCE AREAS OF FOG...WITH VISIBILITIES DOWN TO A HALF MILE OR
LESS AT TIMES IN ISOLATED LOCATIONS. AFTER SUNRISE THIS
MORNING...SHOULD SEE FOG BURN OFF BY 9-10 AM.
SKIES WILL REMAIN MOSTLY SUNNY TODAY WITH HIGHS VERY SIMILAR TO
YESTERDAY...INTO THE UPPER 60S AROUND LAKE SUPERIOR...AND LOWER TO
MID 70S INLAND. IN RESPONSE TO HIGH PRESSURE TO THE EAST AND
STRONG CYCLOGENESIS OVER THE WRN DAKOTAS/NE/WY AREA THIS
AFTERNOON AND TONIGHT...WILL SEE S/SE WINDS INCREASE. A TIGHTENING
SFC PRES GRADIENT COMBINED WITH MODEST BL MIXING WILL PRODUCE
SUSTAINED WINDS AROUND 10 TO 15 MPH AND GUSTS 20 TO 25
MPH...ESPECIALLY OVER NE MN. LIGHTER WINDS ARE EXPECTED TO THE
EAST INTO NW WI.
THE SFC PRESSURE FALLS TO THE WEST WILL CONTINUE ON THURSDAY AS
THE LOW DEVELOPS AND LIFTS TO THE NE THROUGH THE DAKOTAS. THE
STRENGTHENING SYSTEM WILL ALLOW THE SOUTH WINDS TO BE EVEN
STRONGER ON THURSDAY WITH SUSTAINED WINDS AROUND 15 TO 20
MPH...AND GUSTS UP TO 30 MPH. THE INCREASE IN WINDS THURSDAY WILL
ALSO DRAW UP A WARMER AND MORE HUMID AIR MASS...WITH TEMPERATURES
REACHING INTO THE MID TO UPPER 70S...CLOSE TO 80 OVER NE MN...AND
INTO THE LOWER TO MID 70S IN WI. DWPTS WILL RISE INTO THE MID TO
UPPER 50S. EVEN THOUGH MOST OF THE FORECAST AREA WILL SEE S/SE
WINDS...WINDS ACROSS WRN LAKE SUPERIOR WILL BE E/NELY AND STRONG
ENOUGH TO ALLOW THE COOLER AIR OVER THE LAKE TO SPILL INTO THE
NEAR LAKE AREAS...INCLUDING THE TWIN PORTS. THE DULUTH/SUPERIOR
AREA ON THUR COULD ACTUALLY ONLY SEE HIGHS IN THE UPPER 60S.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 322 AM CDT WED SEP 25 2013
GFS AND 00Z ECMWF ARE THE QUICKEST WITH THE SYSTEM EXPECTED TO
AFFECT THE FA THROUGH THE WEEKEND. THEY BRING RAIN TO THE WESTERN
EDGE LATE THURSDAY NIGHT. MEANWHILE...THE GEM/NAM KEEP THE RAIN OUT
OF THE AREA THURSDAY NIGHT. HOWEVER...ON FRIDAY ALL MODELS BRING
RAIN WITH SOME ISOLD THUNDER TO ALL BUT NW WI AS DRY AIR HANGS ON
FROM THE HIGH OVER THE EASTERN GREAT LAKES. HAVE KEPT NW WI DRY ON
FRIDAY AND BEGUN TO RAMP UP POPS OVER THE WESTERN THIRD OF THE FA.
THIS AREA WILL BE UNDER STRONG SW FLOW WITH H85 LLJ TO 45 KT AND
EMBEDDED PIECES OF ENERGY IN THE STRONG FLOW MOVING OVER THIS AREA
THROUGH THE DAY. ON FRIDAY NIGHT...THE RIDGING OVER NW WI BEGINS TO
BREAK DOWN AS VIGOROUS UPPER LEVEL TROF MOVES THROUGH THE NORTHERN
PLAINS. ATTENDANT COLD FRONT WILL BE SOMEWHERE OVER NE MN FRIDAY
NIGHT...BUT TIMING DIFFERENCES AMONGST THE MODELS MAKE IT DIFFICULT
TO PINPOINT. HAVE MENTIONS OF ISOLD THUNDER FRIDAY NIGHT WITH GOOD
INSTABILITY IN PLACE. UPPER TROF WILL BE OVERHEAD ON SATURDAY WITH
RAIN CHANCES INCREASING ACROSS THE AREA. THINGS BEGIN TO WIND DOWN
SATURDAY NIGHT AS THE UPPER TROF PUSHES E OF THE FA. HAVE TRENDED
THE POPS ACCORDINGLY. LINGERED SOME POPS OVER THE EASTERN NW WI AREA
DUE TO TIMING ISSUES AMONGST THE MODELS SUNDAY MORNING. DID REMOVE
THE RAIN MENTION SUNDAY AFTERNOON WITH QUASI-ZONAL FLOW SETTING UP.
NEXT OPPORTUNITY FOR RAIN COMES INTO FOCUS ON TUESDAY AS NEXT COLD
FRONT IS DUE TO CROSS THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1255 PM CDT WED SEP 25 2013
THE LOW CLOUDS AND FOG HAVE CLEARED OFF FOR ALL OF THE TAF
SITES...BUT A LARGE AREA OF STRATUS AND FOG REMAINED ACROSS LAKE
SUPERIOR EARLY THIS AFTERNOON. THE HIGH RESOLUTION MODELS INDICATE
THE LOW CLOUDS AND FOG WILL AGAIN STREAM INTO THE INTERIOR AREAS
OF THE ARROWHEAD DURING THE EVENING...BECOMING DENSE ONCE AGAIN.
HAVE HIT FOG HARD FOR THE NIGHT AND EARLY ON THURSDAY. THINK THE
MAJORITY OF SITES WILL NOT SEE THE DENSE FOG BUT MORE PATCHY FOG.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 69 49 72 60 / 0 0 0 10
INL 73 48 75 58 / 0 0 0 10
BRD 73 53 81 62 / 0 0 0 10
HYR 71 45 74 55 / 0 0 0 0
ASX 69 44 72 56 / 0 0 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...DAP
SHORT TERM...BJT
LONG TERM...GSF
AVIATION...DAP
AREA FORECAST DISCUSSION
NWS GLASGOW MT
322 PM MDT WED SEP 25 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH FRIDAY...
WITH THE RAIN EVENT NOW UNDERWAY ACROSS NORTHEAST MONTANA...SHORT
TERM MODEL SOLUTIONS HAVE MORE OR LESS CONGEALED AROUND A FAIRLY
GOOD CONSENSUS OVER THE LAST FEW MODEL RUNS.
FORECAST CHALLENGES WILL FOCUS MAINLY ON THE
TIMING...INTENSITY...AND AMOUNT OF PRECIPITATION RESULTING FROM
THIS RAIN STORM.
MOST OF THE DAY TODAY...AND LITTLE BIT TONIGHT...THE NARROW LINEAR
BAND OF RAIN MOVING THROUGH OUR CENTRAL ZONE FROM SSW TO NNE HAS
BEEN AND WILL CONTINUE TO BE THE DOMINANT FEATURE. THIS HAS BEEN
WELL REPRESENTED BY THE MODELS WITH THE GFS AND THE HRRR BEING THE
MOST ACCURATE. EXPECT MOST OF THE REMAINING CWA TO FILL IN WITH AT
LEAST A WETTING RAIN OVER THE NEXT 24 HOURS AS A PINCHED OFF LOBE
CENTER FROM THE DEEP UPPER LEVEL TROUGH MOVES RIGHT OVER OUR CWA.
EXPECT MOST PRECIPITATION AMOUNTS FOR THE STORM TO BE BETWEEN 0.20
AND 0.60.
WINDS FILTERING IN THE BACKSIDE OF THIS SYSTEM FROM THE NORTHWEST
WILL BE STRONG ENOUGH TO JUSTIFY A LAKE WIND ADVISORY FROM THURSDAY
MORNING THROUGH LATE THURSDAY NIGHT...WHICH HAS BEEN ISSUED.
SHOULD BEGIN IN THE 15G25KT RANGE...INCREASE TO NEAR THE 20G30KT
RANGE DURING THE AFTERNOON AND DIMINISH AGAIN INTO THE 15G25KT
RANGE AFTER SUNSET.
BY OVERNIGHT THURSDAY NIGHT TO EARLY FRIDAY MORNING...EMBEDDED
WITHIN THE LARGER SCALE TROUGH...A SHORT WAVE RIDGE WILL
TEMPORARILY BRING A LULL IN THE RAIN FOR A GOOD PART OF OUR CWA.
THEN...AS THE MAIN TROUGH AXIS PASSES OVER EASTERN MONTANA...A
BAND OF RAIN WILL LINE UP AND GLANCE OUR SOUTHEASTERN ZONES
THROUGHOUT THE REMAINDER OF THE FORECAST PERIOD.
TEMPERATURES WILL BE QUITE COOL...BUT NOT COLD ENOUGH TO RESULT IN
ANY MIXED PRECIPITATION. BMICKELSON
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...
GOING FORECAST IN GOOD SHAPE. THE MEDIUM RANGE MODELS WERE IN BETTER
AGREEMENT WITH NEXT WEEK BRINGING IN ANOTHER TROUGH FROM THE PACIFIC
NORTHWEST. MODELS...IN PARTICULAR THE ECMWF...ARE MORE PROGRESSIVE.
A GENERAL DRY PATTERN WITH A COOLER AIRMASS ARRIVAL TUESDAY LOOKS
GOOD. NO CHANGES. TFJ
PREVIOUS DISCUSSION...
SYNOPTIC SET UP... A LARGE RIDGE RUNS FROM THE SOUTHERN PLAINS...
THROUGH THE UPPER MISSISSIPPI VALLEY... AND INTO THE HUDSON BAY.
AN EQUALLY LARGE TROUGH RUNS FROM THE FOUR CORNERS THROUGH EASTERN
MONTANA AND THE NORTHWEST TERRITORIES WITH A STRONG COLD FRONT
RIGHT BETWEEN THE TWO LARGE FEATURES. TO THE WEST... A WEAK RIDGE
RUNS UP THE US WEST COAST WITH A TROUGH SPINNING OVER THE GULF OF
ALASKA AND ARCTIC COLD AIR CHURNING RIGHT BEHIND IT OVER THE
BEARING SEA.
FRIDAY NIGHT THOUGH SUNDAY NIGHT... THE TROUGH ALOFT AND THEN
RIDGE TO THE WEST PASS THROUGH THE AREA. BUT WITH MINIMAL
MOISTURE TO PLAY WITH... CONDITIONS WILL REMAIN DRY WITH A SLIGHT
WARMING TREND.
MONDAY TO TUESDAY... THE GULF OF ALASKA TROUGH WILL PUSH OVER
BRITISH COLUMBIA AND BE AIDED BY A JET ROUNDING ITS PERIPHERY
WHICH SHOULD BRING A CLIPPER STYLE SHORTWAVE AND COLD FRONT
THROUGH THE AREA OVER A 12 HOUR PERIOD IN THIS TIME FRAME. MODELS
ARE HAVING SOME TROUBLE ON TIMING BECAUSE IT RELIES ON THE
SMALL PERTURBATION OF A JET/WAVE OVER THE BEARING SEA STARTING ALL
THE WAY BACK AT FRIDAY NIGHT AND AMPLIFYING AS IT ROUNDS THE BC TROUGH.
THE 00Z RUN OF GFS AND EC APPEAR TO LINE UP AROUND LATE MONDAY
AFTERNOON. BUT... THIS COULD QUICKLY CHANGE. POPS ARE POSSIBLE DURING
THIS PERIOD. BUT... DUE TO THE CLIPPER NATURE WOULD BE VERY SHORT WITH
LIGHT QPF.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT... MODELS ARE STRUGGLING
HERE. A ZONAL TO WEAK TROUGH PATTERN IS ANTICIPATED AND THIS
TYPICALLY MEANS SLIGHTLY BELOW SEASONAL TEMPS. THEREFORE...
TRENDED TEMPS DOWN DURING THIS TIME. GAH
&&
.AVIATION...
VFR WITH PERIODS OF MVFR.
RAIN AND LOW CEILINGS WILL RETURN TO THE AREA TONIGHT. MVFR CEILINGS
AT KGGW AND WEST ARE EXPECTED TO SET IN THIS EVENING AT
KOLF...POSSIBLY GETTING INTO KSDY AND KGDV LATER TONIGHT.
CONDITIONS ARE EXPECTED TO GRADUALLY LIFT LATE THURSDAY.
NORTHWEST WINDS WILL INCREASE TONIGHT WITH SPEEDS OF AROUND 15 KTS.
SPEEDS ARE EXPECTED TO INCREASE TO 20 KTS THURSDAY WITH GUSTS TO
ABOUT 30 KTS. TFJ
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 7 AM THURSDAY TO MIDNIGHT MDT THURSDAY
NIGHT FOR FORT PECK LAKE FOR CENTRAL AND SOUTHEAST PHILLIPS...
CENTRAL AND SOUTHERN VALLEY...GARFIELD...MCCONE...PETROLEUM.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BISMARCK ND
335 PM CDT WED SEP 25 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 335 PM CDT WED SEP 25 2013
THE PRIMARY FORECAST CHALLENGE CONTINUES TO BE THE SEVERE WEATHER
CHANCES ACROSS WESTERN AND NORTH CENTRAL NORTH DAKOTA TONIGHT.
SHORT RANGE MODEL GUIDANCE CONTINUES TO PROG A SHORTWAVE TO LIFT
NORTH ACROSS EASTERN MONTANA AND NORTHWESTERN NORTH DAKOTA
TONIGHT. ITS ATTENDANT SURFACE TROUGH AXIS WILL TIGHTEN UP ACROSS
WESTERN NORTH DAKOTA THIS EVENING AS A RESULT. FURTHERMORE...MODEL
MUCAPE VALUES ARE FORECAST TO RANGE BETWEEN 200-400 J/KG WHILE
DEEP LAYER SHEAR WILL BE UP TO 50 KNOTS. EVEN THOUGH INSTABILITY
IS NOT TERRIBLY IMPRESSIVE...THE COMBINATION OF LOW-LEVEL MOISTURE
CONVERGENCE AND HIGH SHEAR ENVIRONMENT WILL LIKELY BE ENOUGH TO
GENERATE SEVERE THUNDERSTORMS THIS EVENING.
THE LATEST 4KM WRF-NMM AND 3KM HRRR PROG AN MCS TO DEVELOP OVER
SOUTHEASTERN MONTANA AROUND 01Z. THIS COMPLEX IS THEN PROGGED TO
LIFT NORTH ACROSS WESTERN NORTH DAKOTA THIS EVENING. THE HI-RES
MODELS ARE HINTING AT THE MCS MORPHING INTO AN MCV BY THE END OF
ITS CYCLE...GENERATING MORE OF A WIND THREAT. HOWEVER...IF
UPDRAFTS GET STRONG ENOUGH...LARGE HAIL CANNOT BE RULED OUT.
CONTINUED TO INDICATE LARGE HAIL AND DAMAGING WINDS IN THE
AFFECTED ZONES FOR TONIGHT.
PRECIP CHANCES WILL TAPER OFF FROM SOUTH TO NORTH AS THE PARENT
SHORTWAVE LIFTS INTO CANADA THURSDAY MORNING. DRY CONDITIONS ARE
THEN EXPECTED OVER MOST OF THE CWA (SANS NORTHWESTERN NORTH
DAKOTA) BY THURSDAY AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 335 PM CDT WED SEP 25 2013
THE HIGHLIGHTS OF THE EXTENDED PERIOD ARE RAIN AND WIND THURSDAY
THROUGH FRIDAY NIGHT.
WIDESPREAD RAINFALL UP TO ONE INCH IS LIKELY FOR SOME PARTS OF NORTH
DAKOTA THURSDAY MORNING THROUGH FRIDAY NIGHT. GUSTY WINDS AROUND 35
MPH ARE LIKELY ACROSS MUCH OF WESTERN AND CENTRAL NORTH DAKOTA
THURSDAY AFTERNOON.
STRONG FORCING AND AMPLE MOISTURE WILL LIKELY BE IN PLACE ACROSS THE
REGION THURSDAY THROUGH FRIDAY THANKS TO A STRONG UPPER LEVEL
JET...DEEP LONGWAVE TROUGH...AND ISALLOBARIC FORCING ALONG THE
INVERTED TROUGH. SEVERAL UPPER LEVEL SHORTWAVE TROUGHS SHOULD EJECT
OUT OF THE MAIN LONGWAVE TROUGH TO THE WEST. IT APPEARS ONE SHOULD
ARRIVE ON OUR DOORSTEP WEDNESDAY NIGHT...THURSDAY NIGHT AND FRIDAY
NIGHT. THIS WOULD TEND TO FAVOR PRECIPITATION ARRIVING IN WAVES WITH
BREAKS IN BETWEEN.
THERE IS SOME UNCERTAINTY BETWEEN THE MAJOR MODELS AS TO
EXACT LOCATION OF THE HEAVIEST RAIN AND TIMING OF THE MAIN COLD
FRONT PUSH OUT OF THE REGION. THE 12 UTC GFS AND 12 UTC ECMWF APPEAR
TO BE SLIGHTLY SLOWER WITH THE EXIT OF THE SYSTEM AND THEREFORE
PRODUCE MORE PRECIP OVER WESTERN AND CENTRAL NORTH DAKOTA. THE 12
UTC GEM/NAM AND 09Z SREF HAVE THE BULK OF THE RAIN FALLING ACROSS
EASTERN NORTH DAKOTA WITH THE FRONT PUSHING THROUGH EARLIER FRIDAY.
THEREFORE...FOR THIS FORECAST ISSUANCE WENT WITH A BLEND OF THE
MAJOR MODELS WITH A SLIGHT FAVOR TOWARD THE EASTWARD (FASTER) MODELS
AS THE GFS HAS SHOWN A SLIGHT EASTWARD TREND OVER THE PAST FEW RUNS.
DUE TO UNCERTAINTY DID NOT INCREASE CHANCES OF PRECIPITATION FOR
THURSDAY OR FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 107 PM CDT WED SEP 25 2013
VFR CONDITIONS WILL PREVAIL OVER WESTERN AND CENTRAL NORTH DAKOTA
THIS AFTERNOON. THUNDERSTORMS AND ASSOCIATED MVFR CONDITIONS WILL
DEVELOP OVER SOUTHWESTERN NORTH DAKOTA AROUND 00Z TONIGHT AND LIFT
NORTH OVER KDIK AROUND 02Z AND INTO KISN AROUND 04Z. GIVEN THE
UNCERTAINTY OF THE EXACT TIMING...KEPT VCTS IN THE RESPECTIVE TAFS
FOR THIS ISSUANCE. OTHERWISE...WINDY CONDITIONS WILL DEVELOP
AREAWIDE BY THURSDAY MORNING WITH WESTERLY GUSTS UP TO 30 KNOTS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...TM
LONG TERM...AJ
AVIATION...TM
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1157 AM PDT Wed Sep 25 2013
.SYNOPSIS...
An upper level low will continue to impact the region into Thursday
bringing rain showers with an occasional snow shower. A brief dry
period on Friday will allow for some sun and slightly warmer
temperatures. Another wave of moisture is possible for the upcoming
weekend bringing clouds and more rain.
&&
.DISCUSSION...
More adjustments to sky and pop grids for today and for early this
evening made with another update as the westward propagation and
intensification of showers ongoing up over the Northern Mountains
and Idaho Panhandle are not turning out to be as robust as
expected per earlier HRRR runs. Thus more of the Basin and the
East Slopes North Cascades and Okanogan Valley hold onto a partly
sunny forecast for longer interval of today. The expectation that
there is going to be some westward propagation of this shower
activity and daytime heating should result in more convective
cumulus cloud development in the areas currently free of clouds
given the conditionally unstable air-mass contained in the general
trof overhead of Washington and Idaho. /Pelatti
&&
.AVIATION...
18Z TAFS: Upper level low in the area has an area of showers wrapped
into it that is expected to enhance with time during the day as well
as show some progress west up over the northern more mountainous
locations of the aviation area. Otherwise recent morning rainfall
and associated abundant leftover moisture has kept low
cloud/stratus/fog of varying intensity and elevation in the region
that should decrease through the day and into tomorrow. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 56 42 62 39 62 45 / 50 30 10 10 10 30
Coeur d`Alene 55 42 60 37 61 43 / 80 30 10 10 10 40
Pullman 57 40 61 36 63 44 / 40 40 10 10 10 30
Lewiston 62 47 66 43 69 47 / 40 40 10 10 10 20
Colville 61 41 66 34 65 43 / 90 30 10 10 20 30
Sandpoint 53 37 60 34 61 41 / 100 30 10 10 10 60
Kellogg 50 39 57 36 58 39 / 100 50 10 10 10 50
Moses Lake 67 44 69 38 68 48 / 10 10 10 0 10 10
Wenatchee 66 45 67 45 67 49 / 10 10 0 0 30 20
Omak 66 42 68 36 66 45 / 10 10 10 0 40 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
523 PM CDT WED SEP 25 2013
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 249 PM CDT WED SEP 25 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE HIGH
PRESSURE STRETCHING FROM THE WESTERN GULF OF MEXICO TO THE WESTERN
GREAT LAKES AND THEN ONTO QUEBEC. MOST OF THE FOG BURNED OFF
BETWEEN 15-16Z THIS MORNING...AND THEN TRANSFORMED INTO A BKN CU
FIELD OVER CENTRAL AND NORTHEAST WISCONSIN. TEMPERATURES ARE
LAGGING BEHIND A LITTLE BIT AND RESIDE IN THE MIDDLE TO UPPER 60S.
WITH SYNOPTIC CONDITIONS CHANGING LITTLE OVER THE NEXT 24
HOURS...FOG POTENTIAL WILL REMAIN THE MAIN FORECAST CONCERN IN THE
SHORT TERM.
TONIGHT...MID-LEVEL RIDGE AXIS WILL BUILD NORTHEAST ACROSS THE
WESTERN GREAT LAKES WHILE HIGH PRESSURE REMAINS CENTERED OVER
EASTERN ONTARIO AND WESTERN QUEBEC. THE AIRMASS WILL REMAIN
VIRTUALLY UNCHANGED FROM LAST NIGHT...WITH PWATS AROUND 0.40
INCHES...AND A LIGHT EASTERLY COMPONENT IN THE LOW LEVELS WHICH WILL
KEEP A STEADY SUPPLY OF MOISTURE. THE PRESSURE GRADIENT WILL BECOME
TIGHTER OVER WESTERN AND CENTRAL WISCONSIN...AND BL WINDS ARE MORE
MARGINAL IN THESE LOCATIONS FOR WIDESPREAD DENSE FOG. BUT DO NOT
THINK THE GRADIENT WILL BE TIGHT ENOUGH TO PREVENT DENSE FOG FROM
FORMING OVER THE HIGHER TERRAIN OF N-C WISCONSIN. OVER NORTHEAST
AND EAST-CENTRAL WISCONSIN...SURFACE WINDS SHOULD BE CALM FOR MUCH
OF THE NIGHT...AND EXPECT A REPEAT PERFORMANCE OF FOG AND LOW
STRATUS. FOG HEADLINES LOOK POSSIBLE ONCE AGAIN AND WILL GO WITH
AREAS OF FOG/LOCALLY DENSE WORDING. LOWS A COUPLE DEGREES WARMER THAN LAST
NIGHT...IN THE UPPER 30S TO MID 40S.
THURSDAY...AREAS OF FOG...LOCALLY DENSE...WILL CONTINUE TO BE
PRESENT THROUGH 14-15Z. THEREAFTER...SHOULD SEE THE FOG TURN INTO A
CU FIELD...WHICH WILL BURN OFF MID TO LATE AFTERNOON. HIGHS WILL BE
SEVERAL DEGREES WARMER THAN TODAY AND WILL GO WITH LOW TO MID 70S.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 249 PM CDT WED SEP 25 2013
FORECAST CONCERNS THIS PERIOD ON PCPN CHANCES THIS WEEKEND AS HIGH
PRESSURE GIVES WAY TO A COLD FRONT AND UPPER TROUGH THIS WEEKEND.
CHALLENGE LAST FEW DAYS HAS BEEN WITH TIMING. AS WITH LAST
NIGHT...MODELS TENDING TO SPEED THINGS UP WITH BOTH NCEP MODELS
BRINGING FRONT INTO EASTERN WI LATE SAT AFTERNOON. GEM/ECMWF ARE STILL
SLOWER. STILL EXPECT SOME TIMING GYRATIONS, AS PIECE OF ENERGY
THAT WILL ORCHESTRATE THE LIFTING OUT OF THE UPPER TROF INTO THE
NORTHERN PLAINS, JUST ROUNDING THE BACK SIDE OF UPPER LOW OVER PAC
NW. MODELS CONSISTENT WITH MAIN DYNAMICS WITH TROF TO PASS NORTH
AND WEST OF CWA...THOUGH GOOD AVAILABLE MOISTURE /PWS AROUND 1.5/
AND CONVERGENCE ALONG COLD FRONT ENOUGH TO BRING/KEEP POPS INTO
LIKELY CATEGORY.
FLOW TO BECOME MORE ZONAL SUN ONWARD WITH MILD PACIFIC PATTERN
EXPECTED AS WESTERLIES LIE ALONG NORTHERN TIER OF U.S. EXTENDED
PERIODS DOTTED WITH SMALL POPS DUE TO TIMING ISSUES WITH FASTER
ZONAL FLOW.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 523 PM CDT WED SEP 25 2013
FOG WL BE AN ISSUE AGAIN TNGT. BASIC WX PATTERN VERY SIMILAR TO
LAST NGT...SO WL RELY HEAVILY ON PERSISTENCE FOR THE TIMING/EXTENT
OF THE FG IN THE TAFS. ONE SIG DIFF IS GRB/S DWPT IS SEVERAL
DEGREES HIGHER THAN YDA AT THIS TIME...PROBABLY DUE TO LGT NELY
FLOW DOWN THE BAY. THAT MAY ALLOW FOG TO GET GOING HERE A LITTLE
EARLIER.
&&
.MARINE...
ISSUED AT 249 PM CDT WED SEP 25 2013
EXTENDED PERIOD OF SOUTHERLY WINDS FRI NIGHT AND SAT TO
BUILD WAVES OVER LAKE MICHIGAN WITH SMALL CRAFT CONDITIONS EXPECTED.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......TE
AVIATION.......SKOWRONSKI
MARINE.........TE
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 249 PM CDT WED SEP 25 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE HIGH
PRESSURE STRETCHING FROM THE WESTERN GULF OF MEXICO TO THE WESTERN
GREAT LAKES AND THEN ONTO QUEBEC. MOST OF THE FOG BURNED OFF
BETWEEN 15-16Z THIS MORNING...AND THEN TRANSFORMED INTO A BKN CU
FIELD OVER CENTRAL AND NORTHEAST WISCONSIN. TEMPERATURES ARE
LAGGING BEHIND A LITTLE BIT AND RESIDE IN THE MIDDLE TO UPPER 60S.
WITH SYNOPTIC CONDITIONS CHANGING LITTLE OVER THE NEXT 24
HOURS...FOG POTENTIAL WILL REMAIN THE MAIN FORECAST CONCERN IN THE
SHORT TERM.
TONIGHT...MID-LEVEL RIDGE AXIS WILL BUILD NORTHEAST ACROSS THE
WESTERN GREAT LAKES WHILE HIGH PRESSURE REMAINS CENTERED OVER
EASTERN ONTARIO AND WESTERN QUEBEC. THE AIRMASS WILL REMAIN
VIRTUALLY UNCHANGED FROM LAST NIGHT...WITH PWATS AROUND 0.40
INCHES...AND A LIGHT EASTERLY COMPONENT IN THE LOW LEVELS WHICH WILL
KEEP A STEADY SUPPLY OF MOISTURE. THE PRESSURE GRADIENT WILL BECOME
TIGHTER OVER WESTERN AND CENTRAL WISCONSIN...AND BL WINDS ARE MORE
MARGINAL IN THESE LOCATIONS FOR WIDESPREAD DENSE FOG. BUT DO NOT
THINK THE GRADIENT WILL BE TIGHT ENOUGH TO PREVENT DENSE FOG FROM
FORMING OVER THE HIGHER TERRAIN OF N-C WISCONSIN. OVER NORTHEAST
AND EAST-CENTRAL WISCONSIN...SURFACE WINDS SHOULD BE CALM FOR MUCH
OF THE NIGHT...AND EXPECT A REPEAT PERFORMANCE OF FOG AND LOW
STRATUS. FOG HEADLINES LOOK POSSIBLE ONCE AGAIN AND WILL GO WITH
AREAS OF FOG/LOCALLY DENSE WORDING. LOWS A COUPLE DEGREES WARMER THAN LAST
NIGHT...IN THE UPPER 30S TO MID 40S.
THURSDAY...AREAS OF FOG...LOCALLY DENSE...WILL CONTINUE TO BE
PRESENT THROUGH 14-15Z. THEREAFTER...SHOULD SEE THE FOG TURN INTO A
CU FIELD...WHICH WILL BURN OFF MID TO LATE AFTERNOON. HIGHS WILL BE
SEVERAL DEGREES WARMER THAN TODAY AND WILL GO WITH LOW TO MID 70S.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 249 PM CDT WED SEP 25 2013
FORECAST CONCERNS THIS PERIOD ON PCPN CHANCES THIS WEEKEND AS HIGH
PRESSURE GIVES WAY TO A COLD FRONT AND UPPER TROUGH THIS WEEKEND.
CHALLENGE LAST FEW DAYS HAS BEEN WITH TIMING. AS WITH LAST
NIGHT...MODELS TENDING TO SPEED THINGS UP WITH BOTH NCEP MODELS
BRINGING FRONT INTO EASTERN WI LATE SAT AFTERNOON. GEM/ECMWF ARE STILL
SLOWER. STILL EXPECT SOME TIMING GYRATIONS, AS PIECE OF ENERGY
THAT WILL ORCHESTRATE THE LIFTING OUT OF THE UPPER TROF INTO THE
NORTHERN PLAINS, JUST ROUNDING THE BACK SIDE OF UPPER LOW OVER PAC
NW. MODELS CONSISTENT WITH MAIN DYNAMICS WITH TROF TO PASS NORTH
AND WEST OF CWA...THOUGH GOOD AVAILABLE MOISTURE /PWS AROUND 1.5/
AND CONVERGENCE ALONG COLD FRONT ENOUGH TO BRING/KEEP POPS INTO
LIKELY CATEGORY.
FLOW TO BECOME MORE ZONAL SUN ONWARD WITH MILD PACIFIC PATTERN
EXPECTED AS WESTERLIES LIE ALONG NORTHERN TIER OF U.S. EXTENDED
PERIODS DOTTED WITH SMALL POPS DUE TO TIMING ISSUES WITH FASTER
ZONAL FLOW.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1226 PM CDT WED SEP 25 2013
HIGH PRESSURE WILL REMAIN CENTERED ACROSS THE REGION
THROUGH THE TAF PERIOD WITH CONDITIONS REMAINING SIMILAR TO THE LAST
24 HOURS. THE LATEST GUIDANCE SUGGESTS FOG WILL AGAIN CREATE
HEADACHES ACROSS THE REGION TONIGHT...AND HAVE TRENDED MORE
PESSIMISTICALLY WITH CIGS/VSBYS AFTER 06Z. THE FOG LOOKS TO BE MORE
WIDESPREAD OVER NORTHEAST AND EAST-CENTRAL WISCONSIN THAN LOCATIONS
FARTHER WEST...DUE TO LIGHTER BOUNDARY LAYER WINDS...BUT PARTS OF
NORTH-CENTRAL WISCONSIN WILL LIKELY ALSO SEE DENSE FOG. LIKE THIS
MORNING...THE VSBYS/CIGS WILL IMPROVE BETWEEN 14-16Z THU MORNING.
&&
.MARINE...
ISSUED AT 249 PM CDT WED SEP 25 2013
EXTENDED PERIOD OF SOUTHERLY WINDS FRI NIGHT AND SAT TO
BUILD WAVES OVER LAKE MICHIGAN WITH SMALL CRAFT CONDITIONS EXPECTED.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......TE
AVIATION.......MPC
MARINE.........TE