Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/02/18
Area Forecast Discussion
National Weather Service Dodge City KS
523 PM CDT Thu Nov 1 2018
...Updated aviation section...
.SHORT TERM...(This evening through Friday)
Issued at 345 PM CDT Thu Nov 1 2018
The water vapor loop and RAP analysis revealed deep longwave trough
centered across the central CONUS, with northwest flow aloft
starting to reach far western Kansas. An elongated shortwave trough
within the flow was pushing through South Dakota and Nebraska, and
the result of this at the surface was an enhancement of the
northwest surface winds across northeastern Colorado, far
northwestern Kansas and western Nebraska. These strong 20-30 mph
winds are not expected to reach southwest Kansas before sunset, so
winds will remain in the 10 to 15 mph range as a general rule
through the evening.
A secondary northwest wind enhancement is suggested by short term
models during the overnight hours/very early Friday morning, and
this should keep the boundary layer mixed enough to prevent
temperatures from falling much below the lower 40s (mid-upper 30s
out west). On Friday, very narrow shortwave ridging at the surface
will result in light winds throughout the day, and warming 850mb
temperatures into the upper single digits by late in the day should
yield surface temperatures generally in the upper 50s to lower 60s
for highs.
.LONG TERM...(Friday night through Thursday)
Issued at 345 PM CDT Thu Nov 1 2018
The next storm system will be digging down into the Rockies from the
Pacific Northwest region early in the weekend. The general
precipitation signal among the global models is that rain will
develop first across northwest Kansas sometime early Saturday
morning with better chances of rain shifting into central Kansas and
Nebraska later in the day as an elongated surface low extends from
northern Kansas into western Oklahoma. This elongated surface low
will then continue to deepen and contract as it moves into far
eastern Kansas/northwestern Missouri. Fairly strong northwest winds
will be found across western Kansas behind the surface low, with 20-
30 mph wind speeds likely, especially along/west of U283. Winds may
even be stronger than this for a few hours in the afternoon.
Another more significant jet will carve out a formidable storm early
next week across the central CONUS, but like Saturday`s storm, the
early next week storm will also mature well to our east, leaving
southwest Kansas region with just light, scattered rain showers for
the most part. The longwave pattern will then evolve into a very
broad, cyclonically-curved flow regime across much of the CONUS, and
this will result in a larger area of cooler low level airmass
spreading across the central and northern CONUS.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 522 PM CDT Thu Nov 1 2018
VFR conditions will prevail overnight with scattered mid level
clouds in the morning. Winds will generally be from the northwest
at less than 12 knots.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 39 59 40 58 / 0 0 0 30
GCK 36 59 40 58 / 0 0 10 20
EHA 36 64 43 59 / 0 0 0 10
LBL 37 62 41 59 / 0 0 0 10
HYS 38 55 41 56 / 0 0 10 40
P28 41 60 42 62 / 0 0 0 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Umscheid
LONG TERM...Umscheid
AVIATION...Hovorka_42
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
841 PM EDT Thu Nov 1 2018
.UPDATE...
Fairly strong mid level deformation forcing will persist across the
forecast area through 09Z, before quickly weakening as it exits to
the northeast. This will sustain intervals of rain across most of
the area through the night, with the back edge of the more widespread
rain expected to exit northeast of the thumb between 11 and 12Z Fri
morning. Several model solutions suggest some contraction of the
frontal forcing late this evening, which will likely continue to
contribute to some localized areas experiencing some periodic breaks
in the rainfall. The upper wave lifting across the area overnight
however is likely to allow a redevelopment of more widespread light
rain before the entire system lifts off to the northeast just prior
to daybreak. An earlier update was issued to lower pops across the
northern Saginaw Valley as the northern edge of frontal forcing
appears as though it may struggle to reach the city of Saginaw let
alone locals to the northwest. A forecast update will be issued to
further refine the northern edge of the rain shield across the tri
cities region based on regional radar. In light of the clouds and
northerly gradient, the overnight min temp forecast will be nudged up
a couple degrees.
&&
.PREV DISCUSSION...
Issued at 648 PM EDT Thu Nov 1 2018
AVIATION...
Upper level forcing responsible for the low pressure system that
will lift across Ohio tonight will sustain a wide swath of rain from
metro Detroit almost up to MBS. The forcing will begin to wane after
08Z, resulting in a gradual tapering of the steady rain into light
rain showers and/or drizzle through daybreak. There has been some
brief intervals of IFR ceilings within some of the more steadier
moderate rain. During the course of the evening, the northerly
gradient will increase which will advect slightly drier air into the
boundary layer. This and a slight deepening of the inversion heights
should hold ceiling heights predominately MVFR through the night.
With the increase in the north-northeast gradient, there may be some
intervals of gusty winds. A limiting factor for including higher
(above 20 knots) gusts in the terminals will be the likelihood that
the rain cooled boundary layer will sustain just enough stability to
hinder mixing of the higher gusts to the surface.
For DTW...There will be a slight backing of the winds from the north-
northeast this evening to the north-northwest overnight. IFR
conditions just do not appear to be persistent enough this evening
to carry in a prevailing group, with the better chances of a little
more prolonged IFR conditions likely to occur across the higher
terrain to the north and northwest of the airport.
DTW THRESHOLD PROBABILITIES...
* High in ceilings below 5000 ft through Friday afternoon.
PREV DISCUSSION...
Issued at 336 PM EDT Thu Nov 1 2018
DISCUSSION...
Persistent cloud cover, light rain, and northeast to easterly flow
have held temperatures across the Metro region in the mid-40s, with
similar temperatures noted across the Tri-Cities up into the Thumb
region. Temperatures are expected to hold steady in the mid-40s for
the remainder of the afternoon as low pressure nudges northeastward
across central Ohio. Frontogenesis between 850MB - 700MB will push
northward from Flint into the Thumb in response to the northeastward
advancement of low pressure. In turn, the precipitation shield is
expected to encompass the bulk of SE MI for the remainder of the
day, with the exception of northern Saginaw County into Bay and
Midland, which are both far removed from the strongest forcing and
are relatively dry in the low-levels, with dew-point depressions
averaging between 10- 15C between 800MB - 700MB. Latest RAP
soundings have hinted at weak forcing and some saturation in the low
levels across the northern Tri-Cities, so opted to include the
slight chance of precipitation (drizzle) for these locations.
Additional rain is expected overnight through the mid-morning hours
as 800 - 700 MB frontal boundary moves across MI between 06Z - 12Z,
with rain chances further enhanced by embedded shortwaves aloft.
North to northwest flow behind the frontal boundary will effectively
cut off rain chances from west to east as dry air intrudes in the
low to mid- levels. Did carry the slight chance to see lake effect
showers across the Thumb down into eastern Macomb and Port Huron
through Friday evening as cooler northerly flow (850 at -4C, 925 at
0C) ushers into SE MI throughout Friday morning. Rainfall amounts
will widely vary across the CWA, with 1 - 1.5" expected across the
southern Metro area and trace to .25" across the Tri-Cities into the
northern Thumb.
Otherwise, with cold air in place, temperatures will hold below
normal for a daytime high on Friday, ranging between the mid to
upper-40s, and low to mid 30s for an overnight low as the thermal
trough holds steady. A ridge of high pressure will then enter across
the Great Lakes region Saturday which will bring another round of
dry weather as temperatures again hold in the mid to upper 40s for a
high (with ECMWF hinting at lowers 50s for a high across the Metro
region). A strengthen trough digging into the Plains will allow
ridging to develop across the eastern U.S and will aid in returning
temperatures to normal values by Sunday.
Unsettled weather conditions in the extended period as a longwave
troughing pattern sets up across the central US. This will put
Michigan in position to see several waves passing through the area.
First system to close out the weekend will track a surface low out
of the central Plains and through the western Great Lakes. Rain
chances increase through the day Sunday with highest chances
arriving towards the late afternoon and early evening. There looks
to be a brief break in precipitation on Monday afternoon before a
more potent low pressure system is forecast to lift out of the
southern Plains and into the midwest. As it arrives into the
west/central Great Lakes region, it will deepen into a strong
dynamic low pressure system. This will lead to a period of warm and
moist air advection into southeast Michigan. Rain chances will begin
to increase early Tuesday morning and continue through the day.
Gusty southeast winds will also arrive with this system as pressure
gradient strengthens. Still some uncertainty in regards to the track
of this system, but cold air being drawn south by this system and
bring a decent drop in temperatures for Wednesday compared to the
previous day. However, the degree of cold temperatures and winter
precipitation chances will be dependent on the strength and track of
the low.
MARINE...
A low pressure system will lift northeast through the Ohio valley
this evening reaching eastern Lake Erie tonight. A tight gradient
around the low will cause northeast winds to increase this evening
resulting in small craft advisories this evening into tonight for
Lakes Erie and St Clair. Additional small craft advisories are in
effect for the Lake Huron shoreline tonight through Saturday
morning. Initially, northeasterly winds will be gusting at or above
25 knots with waves piling up along the shore. Though winds begin to
decrease Friday afternoon, northerly flow will continue to push
large waves toward shore which should fall below criteria Saturday
morning. Cool northerly flow will persist across the region into the
weekend.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
Lake Huron...Small Craft Advisory until 10 AM EDT Saturday for LHZ421-441>443.
Lake St Clair...Small Craft Advisory until 4 AM EDT Friday for LCZ460.
Michigan waters of Lake Erie...Small Craft Advisory until 4 AM EDT Friday for LEZ444.
&&
$$
UPDATE.......SC
AVIATION.....SC
DISCUSSION...AM/AA
MARINE.......DRK
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.
Area Forecast Discussion
National Weather Service Key West FL
1002 PM EDT Thu Nov 1 2018
.DISCUSSION...In the middle and upper levels( 700-200 mb), latest
available GOES-R satellite imagery overlaid with model streamline
analysis as of 900 pm, detail a burgeoning full latitude trough
over the Central CONUS with its axis positioned from Northern
Minnesota down to Northern Old Mexico. Downstream of that, there
is a deep south southwest to north northeast attendant ridge axis
from the far NW Caribbean Sea extending to east of New England,
from the center of a deep and warm anticyclone east of Belize.
At the surface and in the lower to mid levels(Surface to 700 mb),
latest available GOES-R satellite imagery overlaid with marine
and land surface observations and surface analysis, as of 900 pm,
detail the center of a 1025 mb anticyclone centered over the
Western Atlantic near 32.5N 65W. The Florida Keys lie beneath the
far southwestern periphery of this area within weakening ridging.
.CURRENTLY...As of 900 pm, skies are mostly clear across the
islands and surrounding waters. Temperatures across the islands
are around 80 degrees with dewpoints on the muggy night in the
lower to mid 70s. C-man stations along the Florida Reef and Smith
Shoal Light are southeast near 10 knots. Island platforms are
southeast near 10 mph.
.SHORT TERM...Overnight, gentle southeast flow will continue
across the islands and surrounding waters. As a surface cold
front gradually migrates east across the Western half of the Gulf
of Mexico, in response to the aforementioned developing trough,
local surface winds will become more southerly by 12Z. Weak lower
level confluence combined with moistening in the column, to above
1.50 inches by morning, will result in the development of isolated
showers late tonight. The HRRR has this idea in mid as well. Given
that, just made a minor adjustment to increase rain chances 10%,
to 20% for the overnight period and also decrease the winds
slightly.
&&
.MARINE...Gentle to moderate winds earlier this evening are
becoming gentle now, expected to veer to between southeast and
south by daybreak.
&&
.AVIATION...Overnight, VFR conditions will prevail at both the
KEYW and KMTH island terminals. Southeast winds between 8 and 10
knots, will become south before 12z. Widely scattered showers may
impact either terminal after 18Z possibly resulting in brief
mvfr/ifr CIGS and VIS.
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...None.
GM...None.
&&
$$
Public/Marine/Fire...Futterman
Aviation/Nowcasts....Futterman
Upper Air/Data Collection......DR
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Area Forecast Discussion
National Weather Service North Platte NE
703 PM CDT Thu Nov 1 2018
.SHORT TERM...(This evening through Friday)
Issued at 315 PM CDT Thu Nov 1 2018
Winds will remain up tonight as a cold front crosses the area early
this evening. With the boundary layer remaining mixed tonight, lows
should be mild, with the coldest readings across northwest Nebraska
where upper 20s are expected. Steep mid-level lapse rates and cold
air aloft rotates southeast across the region behind the front this
evening. HRRR has been indicating a band of showers associated with
this despite fairly dry air in place. Will keep the shower chance
going through the evening across northern NE.
Fairly pleasant day on tap for Friday as a surface ridge axis
crosses the area. Winds will turn light southwest as the axis
passes. Some mid and high clouds will be around through the day, so
not completely sunny. Highs will range from upper 40s across
portions of north central Nebraska to upper 50s across western and
far southwest Nebraska.
.LONG TERM...(Friday night through Thursday)
Issued at 315 PM CDT Thu Nov 1 2018
A strong shortwave crosses the Northern and Central Plains Friday
night into Saturday. A warm front will move east across the area
Friday evening, followed by a cold front late Friday night. Light
rain still likely to occur across northern Nebraska Friday night
into Saturday morning. Sounding profiles do not support mention of
snow with warm air aloft. Windy behind the front Saturday, with
gusts of 40 mph expected across western and southwest Nebraska.
Gusts of 30 to 35 mph possible elsewhere.
Unsettled weather for the end of the weekend into the first of next
week. No big storms expected, but a couple of disturbances will
slide southeast within northwest flow aloft. Spotty light
precipitation will be possible, along with near or slightly below
normal temperatures. Gusty northwest winds are also expected as the
disturbances pass, especially on Monday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 702 PM CDT Thu Nov 1 2018
A few isolated rain showers are possible over the next couple hours
at KVTN. However, ceilings will remain above 5000 feet and will
therefore pose little impacts to aviation. Otherwise, VFR conditions
will continue at both sites through Friday afternoon. Calm winds
under 10 knots will persist with westerly winds becoming southerly
by late Friday afternoon.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...Taylor
LONG TERM...Taylor
AVIATION...Kulik
Area Forecast Discussion
National Weather Service Mount Holly NJ
918 PM EDT Thu Nov 1 2018
.SYNOPSIS...
A stalled front just north and west of our region will begin to lift
northward tonight as low pressure moves into the southern Great
Lakes. The low will track into the northeastern U.S. on Friday. A
cold front will then work its way across our area Friday night into
early Saturday as another low tracks along it. High pressure will
then build in on Saturday night and Sunday before shifting to near
the Canadian Maritimes by Monday morning. As low pressure tracks
well to our west early next week, an associated cold front will move
through late Tuesday or Wednesday. High pressure will build in
behind the front for Thursday.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
For the 930 update: main change was to delay how quickly PoPs
increased. So far, the pattern looks closer to the HRRR with
only very light precip possible overnight. Otherwise, no major
changes with this update.
Previous discussion: High clouds were on the increase this
afternoon. Clouds are forecast to thicken and lower tonight.
Showers located in the southern Appalachians and vicinity this
afternoon will continue to move northeastward and they should
reach our region overnight.
Weak impulses traveling in the southwesterly mid level flow will
pass overhead. A low level jet is expected to increase to 60+ knots
as it reaches the coast late tonight. Marginal instability is
forecast to develop. As a result, we will mention a slight chance of
thunder for late tonight.
The wind should remain out of the southwest and it is anticipated to
increase to 10 to 15 MPH with gusts near 20 or 25 MPH. The southwest
flow and the cloud cover will result in a mild night. Low
temperatures are expected to range from the upper 50s to the middle
60s.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
The low level jet is forecast to move away to our northeast on
Friday. A surface low is expected to move from the eastern Great
Lakes on Friday morning to New England on Friday night. The low
should pull a cold front through our region at that time. A
secondary low is expected to ride up the front from Virginia to our
region on Friday night.
Rainfall rates are expected to become enhanced from late Friday into
Friday night in response to the cold front, the secondary low and a
140+ knot upper level jet that is forecast to move overhead. We will
continue to mention the potential for heavy rain at that time.
Rainfall totals of an inch or two may be common in our region with
locally higher amounts possible. We will maintain a slight chance of
thunder on Friday with the presence of marginal instability.
Conditions will remain mild on Friday and Friday night. Highs should
range from the middle 60s to the lower 70s, and lows will likely be
in the upper 40s to the middle 50s.
A southwest wind around 10 MPH on Friday should become northwest on
Friday night with the arrival of the cold front.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Synoptic Overview...A highly amplified upper-level trough is forecast
to cross the Northeast on Saturday as it takes on a negative tilt.
The flow is progressive, therefore it turns more zonal Saturday night
into Sunday. However the next trough amplifies from the Midwest and
Mississippi Valley, but it may shear out as it lifts northeastward
Monday into Tuesday. A more substantial trough is forecast to start
shifting eastward Wednesday, sweeping a cold front off the East
Coast. The main time frame to focus on rain is Friday into Saturday,
then again Tuesday into Wednesday.
Saturday...Unsettled into at least the morning hours as a sharp
upper-level trough takes on a negative tilt as it lifts across the
Northeast. The entire system is forecast to be lifting to our
northeast during the first half of Saturday, resulting in improving
conditions. However, there looks to be a period of time Saturday
when rather gusty winds occur. This is due to cold air advection and
pressure rises as the negative tilt upper-level trough pivots across
our area and then to our northeast. The pressure gradient also
tightens and with deeper mixing developing during the day, north-
northwest winds will be gusty. The forecast soundings generally show
about 30 knots (35 mph) of wind mixing down to the surface across
much of the area, however the winds should diminish quite a bit late
in the day and in the evening as mixing starts to wane and high
pressure begins to build in. It will be much cooler Saturday given
cold air advection and especially factoring in a gusty wind.
For Sunday and Monday...As the flow aloft is more southwesterly
Sunday, surface high pressure builds across our area however it
quickly shifts into New England and then near the Canadian Maritimes
by Monday morning. This will result in less wind Sunday, however the
surface flow then becomes more onshore. As the next upper-level
trough amplifies into the Ohio Valley Monday, a coastal front may
try and work its way northward toward Delmarva. It is less certain
if some showers are able to develop with this feature as the low-
level flow turns more from the southeast, therefore kept it dry
regarding this for now. Clouds and showers are expected to be on the
increase though Monday as warm air advection will be underway in
advance of low pressure moving into the Great Lakes. Some southern
areas Monday afternoon should experience temperatures in the 60s.
For Tuesday and Wednesday...The amplification of an upper-level
trough arriving from the west will play a significant role in the
timing of a couple of cold fronts. The first cold front may be tied
to an initial upper-level through that tends to shear out to the
northeast into Tuesday, then a secondary cold front arrives by later
Wednesday. There is the potential for a decent amount of moisture to
accompany the cold front Tuesday night into Wednesday and therefore
PoPs are kept on the higher side. The warmer flow ahead of the cold
front should allow for temperatures to rise into the 60s for much of
the area on both afternoon`s.
For Thursday...A broad southwest mid-upper flow is expected. While it
looks like the day will be dominated by surface high pressure, mid-
range models are showing weak perturbations in the mid-level flow
that could generate some clouds or even showers. Temperatures should
be more seasonable behind the departing system that affects the
region late Tuesday and Wednesday.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY and surrounding areas.
Tonight...VFR this evening. Increasing and lowering cloud cover
tonight with showers arriving. Conditions falling to MVFR. There
is a small chance of IFR conditions, particularly at KACY, but
don`t have enough confidence to include in the TAF at this time.
South southwesterly winds are expected through the night. Winds
at the surface should gust up to 20 KT, especially late tonight.
Even with the stronger surface winds, concern is increasing
that all TAF sites could have issues with LLWS for several hours
tonight. The prime period for impacts looks to be between 03 and
09Z. A low level southwesterly jet as high as 55 KT will result
in both speed shear and some directional shear. This low level
jet is expected to dissipate before 12Z, and with it, the risk
for LLWS should diminish as well.
Friday...MVFR and IFR conditions in showers. Southwest wind around
10 knots.
Friday night...MVFR and IFR conditions in rain, heavy at times.
Southwest wind 6 to 10 knots becoming northwest.
OUTLOOK...
Saturday...MVFR/IFR probable especially in the morning with some
showers, then conditions improve to VFR. North-northwest winds 15-20
knots with gusts to around 30 knots, becoming west-northwest and
diminishing to near 10 knots late in the day and especially at
night.
Sunday...VFR. Light and variable winds, becoming east to southeast
around 5 knots.
Monday...VFR to start. Then sub-VFR conditions expanding in the
afternoon and overnight due to precipitation. East winds around 10
knots.
Tuesday...Widespread sub-VFR conditions expected in showers/rain.
Southeast winds 10 to 15 knots.
&&
.MARINE...
We will continue the Small Craft Advisory for tonight and Friday
morning with a southwest wind 15 to 20 knots and gusts of 25 to 30
knots. The mild air over the relatively cool water should prevent
the strongest of the winds aloft from mixing to the water`s surface.
However, isolated gale force gusts remain possible.
The Small Craft Advisory ends at noon on Friday for Delaware Bay. We
will continue the advisory on our ocean waters for Friday afternoon
and Friday night with wave heights expected to remain in the 4 to 7
foot range there.
OUTLOOK...
Saturday and Saturday night...Advisory-level seas and winds likely
as directions switch to northwest after cold-frontal passage Friday
night and Saturday morning. Winds will likely increase and be
highest just after frontal passage. Gales are looking more likely.
Lingering showers on Saturday morning.
Sunday...Sub-advisory winds/seas expected with fair weather.
Monday...Sub-advisory winds/seas expected early Monday. Increasing
chance of advisory-level conditions Monday afternoon/night.
Tuesday...Advisory-level conditions are expected to continue as
another cold front begins to work into the Mid-Atlantic.
&&
.HYDROLOGY...
Over the last 24 hours, mid-range models have shifted the heaviest
QPF from north and west of the I95 corridor to over the I95
corridor. The heaviest rain is now expected to fall over the Lower
Schuylkill, Delaware and Lehigh basins in PA, and over the the
Raritan and Passaic basins in NJ. While rain in expected off and on
tonight through early Saturday, the heaviest rain seems to be
concentrated on Friday night. While the models have been shifting
the heaviest core of precipitation the last 24 to 48 hours, timing
of the heaviest rains has been persistent. In all, 1 to 3 inches of
rain is possible with at least 2/3rd falling Friday night.
None of our river or larger stream forecast points are forecast to
flood at this time, but the NW branch of the Rancocas and portions
of the Passaic come close.
Continue to monitor predicted rainfall. If the rainfall comes to
fruition on Friday night, nuisance poor drainage and low-lying
flooding will occur, especially now that leaves have started to
fall. If you live by a flood-prone waterway, rises will commence
later Friday night and Saturday as the runoff makes its way through
the system.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...Small Craft Advisory until 6 AM EDT Saturday for ANZ450>455.
Small Craft Advisory until noon EDT Friday for ANZ430-431.
&&
$$
Synopsis...Kruzdlo
Near Term...Iovino/Johnson
Short Term...Iovino
Long Term...Gorse/Kruzdlo
Aviation...Iovino/Johnson/Kruzdlo
Marine...Iovino/Kruzdlo
Hydrology...
Area Forecast Discussion
National Weather Service Blacksburg VA
947 PM EDT Thu Nov 1 2018
.SYNOPSIS...
A slow moving cold front will bring showers and some
thunderstorms to the Appalachians and central mid Atlantic
region, before moving off to the east on Friday. High pressure
will then build in with improving conditions and cooler
temperatures for the weekend.
&&
.NEAR TERM /THROUGH FRIDAY/...
As of 945 PM EDT Thursday...
The frontal system to our west continues its slow approach
toward the Appalachians and central mid Atlantic region.
The low level wind field ahead of the front remains quite
energetic but abundant clouds and warm air advection are
inhibiting downward momentum transfer. Believe this will yield
some gusty conditions through this evening, especially at the
higher elevations.
Have adjusted location of highest probability of precipitation
based on the latest radar trends and the last few runs of the
HRRR and RAP guidance. Coverage of pre-frontal showers still
expected to gradually diminish to the east.
Waves will slide up along the slow moving front and prevent it
from making a speedy exit to our east. Expect diurnal heating to
generate some surface based instability and reinvigorate
convection east of the Blue Ridge during the afternoon.
While the instability will be lacking there will be ample shear
for any storms to work with, establishing a high shear/low CAPE
environment. SPC has the far eastern portion of our area in a
marginal risk for severe tomorrow and the situation will have to
be watched very closely.
Have increased minimum temperatures in a few locations to
reflect latest temperature trends and RAP guidance. Surface dew
points in the lower 50s to lower 60s and all the cloud cover
will mean little additional drop in temperature tonight.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
As of 300 PM EDT Thursday...
A wave of low pressure will ride north along a surface cold front
Thursday evening briefly slowing its advance east across our region.
Then, the surface cold front heads off to the east Friday night with
its associated 850mb cold front close on its heels. Behind the
front, expect a surge of colder and gustier winds from the northwest.
Scattered showers and isolated thunderstorms will move east across
the area Friday evening into Friday night. Northwest flow Friday
night will create upslope precipitation across the mountains of
southeast West Virginia, southward to Northwest North Carolina.
Temperatures profile support mostly rain showers with a few of the
highest peak cold enough for some very light snow late Friday night
into early Saturday morning. Leaned towards the colder NAM and NBM
in the western mountains for lows. Low temperatures Friday night
will range from the mid 30s in the mountains to the lower 50s in the
piedmont.
It is going to be windy Saturday morning. There may be a narrow
window of opportunity around daybreak Saturday for some locations
near the crest of the Blue Ridge to approach Wind Advisory gust
thresholds. By Saturday afternoon, the gusty northwest flow will
veer north and weaken, Thus reducing upslope clouds and showers.
High temperatures on Saturday will vary from the lower 40s in the
northwest mountains to the lower 60s in the piedmont.
1028 mb high center will build over West Virginia Saturday night
into early Sunday. Saturday night will be cold with readings from
the upper 20s in the west to near 40 degrees in the east.
On Sunday, the high center will lift northeast and reach the
Canadian Maritimes. A southwest flow will moderate high temperatures
Sunday with readings from the lower 50s in the mountains to the
lower 60s in the piedmont. As a cold front approach from the west,
southerly flow will advect moisture into the area Sunday night.
Increased pops for Sunday night as supported by 12z run. The ECMWF
is quicker than GFS with QPF Sunday night. Low temperatures Sunday
night will generally be from the mid 30s in the northwest to the mid
40s in the southeast.
Forecast confidence is moderate with the greatest uncertainty being
the timing and expanse of a return of rain Sunday night.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 300 PM EDT Thursday...
Upper level ridging along the East coast will continue Monday. Then,
a healthy persistent long wave trough will be carved out over the
central and eastern CONUS. A series of frontal/low pressure systems
will accompany a couple of shortwaves across the CONUS, resulting in
a period of relatively active wet weather. Also, the lingering
stationary front may push back toward the coast and bring the
potential for precipitation back to the Northeast. As such, the
first half of the week is looking wet for the eastern CONUS with
abundant cloud cover and high likelihood for rain from Monday into
Wednesday. Drier weather may be possible Thursday into Friday as
high pressure settles over the region. Plenty of clouds and rain
will result in near to below normal temperatures.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
As of 750 PM EDT Thursday...
Expect conditions to deteriorate through tonight as to southwest
surface to low level winds ahead of the slow moving front to
our west continue to bring moisture into the central and
southern Appalachians. Ceilings will lower MVFR or IFR with the
lower values at higher elevations. Scattered showers will
continue mainly along and west of the Blue Ridge.
Once heating and mixing begin Friday morning ceilings will lift
a bit and reinvigorate showers. Some thunder possible mainly in
the foothills and to the east. Any thunder at KROA, KLYH or KDAN
will be after 16Z/noon.
The low level wind field is quite energetic but abundant clouds
and warm air advection are inhibiting downward momentum
transfer. Believe this will yield some gusty conditions through
this evening, then LLWS as most locations decouple beneath the
low level jet. The low level flow will be relaxing on Friday but
there may be some gusts especially with convective elements in
the east, especially during the afternoon.
Confidence is average for all elements.
Extended Discussion...
Front will be east of the area after 00Z/8PM Friday. Rain pulls
out by early Saturday with some limited MVFR cigs in the
mountains Saturday, with a brief period of gusty nw winds. VFR
Sat afternoon into Sunday as high pressure builds in. The chance
for precipitation and poor flight conditions returns for Monday
and Tuesday.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...MBS
NEAR TERM...AMS/MBS
SHORT TERM...KK
LONG TERM...KK
AVIATION...AMS/MBS
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
745 PM EDT Thu Nov 1 2018
.UPDATE...
The weather pattern during the rest of the week will be
dominated by a strong cold front approaching from the
northwest. A couple bands of showers and isolated
thunderstorms have gradually been developing over the
northeastern Gulf of Mexico along the prefrontal trough, and
are starting to push east into the Nature Coast. HRRR
guidance has been showing this convection holding together
through around 06z before gradually dissipating, then mostly
rain free conditions holding through the rest of the
overnight hours. Farther south, an area of light stratiform
rain that developed over Highlands and Polk counties this
afternoon is now pushing west and out of the region.
Rain chances were increased for the next few hours over the
Nature Coast and adjacent Gulf waters, but as previously
stated, these rain chances should diminish by 06z.
Otherwise, no significant changes are needed for the
evening update.
&&
.AVIATION...
Mostly rain free conditions expected overnight and through
the morning hours at area terminals, although an isolated
shower moving off the Gulf overnight and causing brief
flight category disruptions cannot be ruled out. Some
patches of fog or low stratus will be possible during the
early morning hours, mainly around KLAL, KPGD, KFMY, and
KRSW. Areas of showers and thunderstorms will push southeast
into the area beginning Friday afternoon, with periods of
MVFR-LIFR conditions expected through the afternoon and
evening hours.
&&
.MARINE...
High pressure to the northeast of Florida will shift east
through the next couple of days as a cold front approaches
from the northwest. Southerly winds tonight will turn to
southwesterly on Friday as numerous showers and
thunderstorms spread through the waters ahead of the cold
front. The front will pass south late Friday and Friday
night, with winds turning to northwesterly and northerly. A
tight pressure gradient between the ridge and cold front
will keep winds near cautionary levels Saturday, with higher
winds and locally hazardous seas expected with some of the
stronger storms Friday and Friday night.
&&
.Preliminary Point Temps/PoPs...
TPA 72 81 63 75 / 10 70 50 10
FMY 70 85 71 81 / 10 50 60 20
GIF 69 84 64 75 / 10 50 50 10
SRQ 73 83 67 77 / 10 70 50 10
BKV 68 81 59 74 / 10 80 50 0
SPG 73 82 65 75 / 10 70 50 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...Beach Hazards Statement through Tuesday evening for
Coastal Manatee-Coastal Sarasota-Pinellas.
Gulf waters...None.
&&
$$
18/Fleming