Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/02/17
Area Forecast Discussion
National Weather Service Duluth MN
523 PM CST Fri Dec 1 2017
.SHORT TERM...(This evening through Saturday)
Issued at 337 PM CST Fri Dec 1 2017
Fairly quiet forecast through Saturday, with the main story being
cloudy skies tonight, and a chance of light snow over the tip of
the Minnesota Arrowhead tonight. The main focus is on a shallow
mid-level shortwave, which is evident on current water vapor
satellite imagery over central North Dakota as of 21Z this
afternoon. There is a weak embedded pulse of positive vorticity
advection within this wave, which should move through this evening
and overnight. RAP soundings indicate that there is a good amount
of dry air near the surface, with the dry air layer being more
shallow over the Arrowhead this evening. With cloud bases near 7
to 10k feet this afternoon, very little, if any, precipitation has
reached the ground, so QPF may be lower than what is forecast,
which is only between 0.01 to 0.05" over the Arrowhead. Cold
temperatures tonight, with lows in the lower to middle 20s over
the Northland.
Saturday is looking like a nice day as the shortwave exits the
region, and mid-level ridging develops over the Dakotas. Another
mild day is expected, with highs in the middle 30s north to the
lower 40s south. Skies should be mostly sunny, although some cirrus
clouds may develop over our southwestern counties by the
afternoon.
.LONG TERM...(Saturday night through Friday)
Issued at 337 PM CST Fri Dec 1 2017
The main challenges for the long term involve a passing storm
system early next week and a period of near or below normal
temperatures.
A progressive upper level pattern will continue into Saturday
evening. Ridging will build over the Northern Plains and Upper
Midwest through Sunday morning as a jet streak digs into northern
California and moves into the central Rockies. Another speed max
will move into the Cascades as the western trough deepens over
the Rockies. Southerly return flow will develop on Sunday as the
upper ridge advances east of the region and surface high pressure
drifts eastward as well. Lee cyclogenesis is forecast over
Wyoming and northern Colorado Sunday afternoon. The weak and
somewhat disorganized initial low will move eastward into the
central Plains along a baroclinic zone stretching from north
Texas into northern Minnesota. The low is forecast to intensify
Sunday night and Monday bringing precipitation to the Upper
Midwest. With warm temperatures across the area during that time,
we think precipitation will begin as rain Sunday afternoon
changing to a wintry mix of rain, snow, and sleet across our
northern zones overnight. The system continues to intensify on
Monday and the deterministic models have come into reasonable
agreement with the placement of the surface low. Details aloft
are more diverse and contribute to merely average confidence at
this time. The GEM is a bit stronger with the storm system.
Meanwhile the GFS and ECMWF solutions feature a slightly weaker
system stretched from eastern Kansas to Lake Superior. All three
models seems to feature a mesoscale precipitation band which is
either near or over northwest Wisconsin. With this forecast
package, we have reduced the potential for freezing rain over
northern Minnesota and brought a faster change to snow from
rain/mixed precip. Even with the warm temperatures, mesoscale
forcing and diabatic cooling should affect a quick change to all
snow along and northwest of wherever the band sets up. Confidence
is average with the details and a shift of 75 miles northwest or
southeast is certainly possible. With all those caveats in mind,
there is a potential for more than 3 inches of snow over far
northern Minnesota and northwest Wisconsin, with lower totals
between those areas including central and east-central Minnesota.
The upper level trough is expected to lift northeastward out of
the region Tuesday afternoon and evening pulling the surface low
toward Hudson Bay. Cold air advection behind the departing system
will keep a chance of snow showers for northern Minnesota and
lake effect snow for northwest Wisconsin into Wednesday morning.
The lake effect snow chances then continue into Thursday as
temperatures across the region tumble. High amplitude ridging
will develop over the western third of the continent and
northwest flow is expected over the Northern Plains and Upper
Midwest through the remainder of the week. Mid- and low-level
winds will pour Arctic air into the region with temperatures
dipping to near and then below normal by Wednesday. Daytime highs
are expected in the teens to near 20 with overnight lows in the
single digits. Another ripple in the mid-level flow will dive
toward the Northland Thursday and Friday which could bring
another shot of snow.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 521 PM CST Fri Dec 1 2017
VFR for the TAF period - probably could have done 1-liners, but
timed the break in VFR ceilings. Light winds, no concerns.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 26 39 27 41 / 10 0 0 30
INL 21 35 24 39 / 10 0 0 10
BRD 26 42 27 41 / 0 0 0 20
HYR 25 43 27 45 / 10 0 0 20
ASX 28 43 28 47 / 20 0 0 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...None.
&&
$$
SHORT TERM...JTS
LONG TERM...Huyck
AVIATION...Wolfe
Area Forecast Discussion
National Weather Service Jacksonville FL
920 PM EST Fri Dec 1 2017
.UPDATE...A weak sfc front will remain over south/southeast GA
through tonight resulting in light and variable low level wind flow
over the region. Sfc high pressure is located across the Mid
Atlantic states. A weak shortwave trough is currently passing west
to east across our forecast area with primary result mid cloud deck
and a few sprinkles over the Suwannee Valley area. With time, the
area of cloudy skies will translate slowly toward the east and
slowly break up as lift weakens. Little mid forcing for any
uptick in rain chances, associated with shortwave which are
currently only 5-10 percent. For the evening update...just minor
adjustments for increasing clouds across the mid section of the
forecast area and adjust min temps up a bit due to mid level clouds.
Think fog potential is fairly low and not expecting much more than
patchy to areas of fog. Best chances of more fog/some areas of
dense fog appear to be west of a line from Alma to Live Oak based
on latest HRRR and SREF guidance.
&&
.AVIATION...VFR expected to prevail tonight with low to moderate
chance of MVFR vsby for brief time between about 08z-14z. Light to
calm wind tonight becomes light south-southwest Saturday...with
an aftn sea breeze expected at SGJ, SSI and later in the afternoon
at CRG.
&&
.MARINE...Light and variable winds and low seas through Saturday
with sea state dominated by wind-sea swells of about 7-9 seconds.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 56 76 54 71 / 10 0 10 10
SSI 59 75 58 69 / 0 0 10 10
JAX 58 80 57 74 / 0 0 10 10
SGJ 58 77 59 73 / 0 0 10 10
GNV 56 79 55 77 / 0 0 10 0
OCF 56 80 55 77 / 0 0 0 0
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...None.
&&
$$
Shashy/23/McGinnis
Area Forecast Discussion
National Weather Service Midland/Odessa TX
544 PM CST Fri Dec 1 2017
.DISCUSSION...
Please see the 00Z aviation discussion below.
&&
.AVIATION...
Models continue to indicate the development of stratus overnight,
which looks to mainly affect MAF. There remains some uncertainty,
though if stratus develops, IFR conditions could persist as late
as 17/18Z. Thus, have maintained mention at MAF, and will monitor
and amend as needed for MAF and possibly INK. Otherwise, VFR
conditions with abundant mid/high clouds will continue, with
light/variable winds becoming northeasterly by Saturday afternoon.
&&
.PREV DISCUSSION... /issued 212 PM CST Fri Dec 1 2017/
DISCUSSION...As of 2:00 pm CST Friday...various satl imagery`s
shows plenty of high clouds streaming overhead in SW flow aloft.
An upper low is spinning west of the Baja California coast.
High resolution models such as the HRRR and RAP13 are indc the
possibility of low clouds tonight. However...if the high clouds
persist it might inhibit the low clouds. Guess we`ll just have to
wait and see on whether low clouds develop.
Looks like dry weather is in store for the CWA for the next seven
days. The Canadian (GEM) model is the outlier showing some precip
on Tuesday associated with an upper trof and sfc cold front.
Since the GFS...most GFS ensembles...and the ECMWF do not show
precip have kept the forecast dry.
Temps will bounce around some this week. The upper low off the
Baja coast will open into a wave and dampen as it moves east.
Zonal flow will keep temps well above normal through Monday
(normal for MAF is 60). An upper trof in the Gulf of Alaska will
move into the Pacific NW and then move across the Plains on
Tuesday. It looks like the best forcing and dynamics remain north
and east of the CWA. MOS guidance brings much colder temperatures
to the CWA (10 degrees or so below normal) along with strong
winds. It`s still a little ways off so we`ll see what future model
runs show with the winds. Temperatures moderate in NNW flow aloft
the the middle and end of next week as the core of the Arctic
airmass moves east into the Midwestern states.
Strobin
&&
.PRELIMINARY POINT TEMPS/POPS...
Big Spring 49 75 53 73 / 0 0 0 0
Carlsbad 43 73 47 75 / 0 0 10 0
Dryden 51 78 54 75 / 0 0 0 0
Fort Stockton 50 76 53 76 / 0 0 0 0
Guadalupe Pass 50 71 49 67 / 0 0 10 0
Hobbs 41 72 46 71 / 0 0 0 0
Marfa 37 73 40 73 / 0 0 0 0
Midland Intl Airport 48 74 52 73 / 0 0 0 0
Odessa 48 74 51 73 / 0 0 0 0
Wink 44 76 50 76 / 0 0 10 0
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...None.
TX...None.
&&
$$
Area Forecast Discussion
National Weather Service Miami FL
835 PM EST Fri Dec 1 2017
.UPDATE...
With the new SREF showing decent probability of fog in the
interior, have went ahead and added fog to the forecast for most
of the interior in the early morning hours. Some of the fog may
bring visibility down to one half mile, or less. The HRRR is still
showing no reduction in visibility, so, there is still uncertainty
tonight. Otherwise, no significant change to the forecast, just
tweaks to account for current conditions.
&&
.PREV DISCUSSION... /issued 705 PM EST Fri Dec 1 2017/
AVIATION...
Overall, benign weather expected tonight. There may be a few
passing light showers down in Miami-Dade County, but confidence of
occurrence is too low to include any VCSH mention in the TAFS.
Winds will be light and variable over the next several hours,
before increasing out of the east northeast around 10 KT aft
02/1400Z.
PREV DISCUSSION... /issued 334 PM EST Fri Dec 1 2017/
DISCUSSION...
Fairly persistent pattern for the next several days, as high
pressure is in place to the north. This should keep the wind out
of the northeast until at least the beginning of next week. Also,
while a few isolated showers will be possible, most of the area
should see dry weather. PWATs this morning are below 1 inch,
indicating even areas that see some showers, will probably not see
much in the way of accumulations.
This pattern should continue through the beginning of next week.
The change in the pattern will come from an approaching front,
which will be be in association with a strong 500mb trough. This
trough will dig from well to the north in Canada, down to the
Florida peninsula by the latter half of the week. This will drive
the front well through the area on Thursday. As it does, it will
increase chances for showers, and possibly a few isolated
thunderstorms on Wednesday, through possibly Thursday morning.
Behind the front, models are currently indicating a cool down,
with highs reaching into the 70`s on Thursday, and then maybe mid
60`s in the western Lake region to low 70s along the Atlantic
coast, for Friday.
MARINE...
High pressure north of the area will keep the northeasterly flow
across the South Florida waters through the beginning of next
week. The wind may pick up to around 20 kts at times, which may
cause hazardous boating conditions for small craft. It also would
keep a moderate to high chance of rip currents for the Atlantic
beaches through the weekend. A cold front is forecast to move into
the area for the middle of next week. This will cause chances of
showers to increase, as well as pick up the wind behind the front,
causing seas to build in the Gulf as well as the Atlantic waters.
&&
.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach 69 80 68 79 / 10 10 10 10
Fort Lauderdale 70 80 69 79 / 10 10 0 10
Miami 71 81 69 81 / 10 20 0 0
Naples 65 83 65 82 / 10 0 0 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
GM...None.
&&
UPDATE...13
DISCUSSION...13
MARINE...13
AVIATION...27/JT
Area Forecast Discussion
National Weather Service Melbourne FL
845 PM EST Fri Dec 1 2017
.UPDATE...
Tonight...Weak high pressure ridge will continue over north Florida
and produce light winds down into our northern areas. Min temps are
forecast in the upper 50s to around 60 degrees over the interior
and north coast. Onshore flow over the south will be weaker than
previous nights, so mins there look a few degrees lower in the
lower/mid 60s.
The main weather item of interest will be fog chances. Guidance
doesn`t agree as the HRRR and local WRF models do not show much fog.
MOS shows IFR-LIFR along/west of I-4 towards sunrise though. Low
level winds will be lighter due to the influence of the high
pressure ridge. Some mid level cloudiness may affect the
climatologically favored areas for fog in the north and the ground
there has not been rain wetted in the past week. Our current
forecast has a chance of fog over a quite large area, with a higher
mention near/west of I-4. Don`t have enough confidence to make
changes to that forecast.
&&
.AVIATION...
VFR conditions until after midnight, then there is a potential for
fog again from the pre-dawn hours until a little after sunrise. The
greatest chance should be at the interior terminals and KDAB. Only
have MVFR visibility in the TAFs, with IFR at a couple spots for
now. Wouldn`t expect the fog to last too long after sunrise since
MOS guidance isn`t showing a ceiling.
&&
.MARINE...
Weekend...Generally good boating conditions. Weak pressure gradient
indicated with winds below 10 knots in the north and around 10 knots
in the south. Seas will be 3 feet or less except in the south
Saturday where an east swell may produce seas up to 4 feet.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
&&
$$
FORECASTS...Lascody
IMPACT WX...Johnson