Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/25/18
Area Forecast Discussion
National Weather Service Binghamton NY
840 PM EDT Tue Apr 24 2018
An approaching low pressure system will bring rain tonight into
Wednesday. Rain will taper off to showers Wednesday and then
gradually diminish Wednesday night into Thursday. Another
system will yield a good chance of rain Friday into Saturday.
.NEAR TERM /THROUGH WEDNESDAY NIGHT/...
842 PM update...
The models continue to be too aggressive advecting precipitation
into a very dry airmass, indicated by dew points in the 30s. We
slowed the advance of the precipitation into our counties early
this evening by a few additional hours.
Precipitation should fill in as humidity rises in the lower
atmosphere late this evening.
The latest grid update has been sent.
3 PM update...
Mid and high clouds making some progress into the area this
afternoon well ahead of the rain and the center of the storm.
Clouds weren`t fast enough to slow the temperatures making it
into the mid and upper 60s and lower 70s. At low levels still
dry with the rain across western NY and central PA. Rain is
making slow progress and will only get into the far west and
southwest early evening, then to most of the CWA by midnight.
The stacked low moving northeast out of the Carolinas will
channel Atlantic moisture northwest into the area ahead of it.
Steady rain will be over the area late tonight into Wednesday
then start to lift northeast. The rain will be slow to end as
the northern and southern streams try to phase over our area
late Wed. Wed night the remaining wrap around rain showers lift
northeast into mostly CNY by sunrise.
Rainfall amounts are similar with half an inch to an inch across
most of the area. 1 to 1.5 inches possible in the upslope
regions of the southern Catskills to the Poconos. The entire
area has now had several days of dry weather so this amount of
rain over a long period shouldn`t be an issue. Thunderstorms
should stay along the coast. Over our area low and mid levels
will be saturated and stable.
Temperatures closer to normal with lows in the 40s both night
and highs Wednesday in the 50s.
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
Upper low pulls east into western New England on Thursday.
Instability and cool air will result in scattered showers with
below normal temperatures. Brief ridging on Thursday night into
early Friday ahead of a fast moving low. Significant differences
exist in the models with the EURO dry Friday while the NAM/GFS
bring showers across the area as the low shears apart. With
continued upper trofiness, better chance that there will be a
few showers than none so have included chance pops during the
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Long wave trof will be over the area for the weekend keeping
cool air and unsettled weather for the region. Best chance for
showers will be on Saturday as a short wave rotates through the
trof enhancing the instability. Drier air and some ridging
arrives for Sunday and Monday. Expect temperatures to return to
near of slightly below normal on Monday as the air mass modifies
and heights build aloft.
.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
800 PM Update...Mid and high level clouds have now overspread
the forecast area. CIGS will gradually lower this evening (5-10k
ft agl) with rain showers also developing from southwest to
northeast between about 01z - 06z. Occasional MVFR CIGS or VIS
may impact the taf sites later this evening into the first part
of the overnight as rain continues to overspread the region.
Fuel alternate CIGS are forecast to develop very late tonight
into Wednesday morning at most sites.
Confidence is lower during the day on Wednesday, as model
guidance differs on where the steadier rain will track. Leaned
toward the wetter, further west solutions of the HRRR, RAP and
ECMWF for now. This could bring additional periods of fuel
alternate or borderline IFR CIGS and/or VIS to the taf sites
into Wednesday afternoon. A front will slowly work its way
through the area from NW to SE later Wednesday and Wednesday
evening. Behind this front winds shift out of the NW with ample
low level moisture present for BR and continued restrictions.
South-southeast winds 8 to 15 kts this evening should shift more
east-southeast overnight, decreasing between 5 to 10 kts. Winds
become light and variable for a time Wednesday afternoon a slow
moving front approaches. Winds turn northwest early Wednesday
evening behind this front...less than 10 kts.
Wednesday night into Thursday morning...Restrictions likely
with rain showers. High confidence.
Thursday afternoon and Thursday night...Generally VFR. Moderate
Friday to Saturday night...Some restrictions possible in
periods of rain showers. Moderate confidence.
Sunday...VFR. Moderate confidence.
Area Forecast Discussion
National Weather Service Louisville KY
950 PM EDT Tue Apr 24 2018
Issued at 949 PM EDT Tue Apr 24 2018
Upper level low will continue to move slowly eastward overnight.
Plenty of low level cloud cover will be seen along with scattered
areas of light rain and drizzle. Main area of drizzle and light
rain will be found across the west late this evening and this should
shift into the eastern sections overnight. Overnight lows in the
lower 50s still look good for tonight. Did a quick refresh of the
short term grids. This resulted in very little change to the
.Short Term...(This evening through Wednesday night)
Issued at 340 pM EDT Tue Apr 24 2018
The upper low that has persisted the last couple of days across
central Kentucky is becoming more disorganized this afternoon
(less vertically stacked in nature). There is a diffuse middle and
upper level circulation centered between Bowling Green and Glasgow
Kentucky with the main surface low displaced over South Carolina
with an inverted trough extending northward into eastern Kentucky
and West Virginia.
There has been some entrainment of drier air from the south and
southeast around this circulation that may help overturn some
lower level higher theta-e air. Given the sharp vorticity
gradients and potential for some insolation, will keep the
small mention of thunderstorms across the southeast part of the
WFO LMK forecast area. There has been intermittent moderate rain
showers over parts of Monroe and Cumberland counties near the
Kentucky-Tennessee border, but updrafts have not been organized
enough to support charge separation for thunderstorm development
at this time. The potential will still be there through this
Anticipate a diurnal downturn in convective activity late this
afternoon and this evening. Persistent cloud cover and light winds
tonight will limit any significant drop in temperatures
overnight and mitigate any fog development.
Going into Wednesday, the upper low will be slow to move along the
mid-Atlantic coast. With high pressure slowly building in,
steering currents will be too weak to completely scour out the
deeper layer moisture. Will keep skies mostly cloudy for tomorrow
and tomorrow night. The diurnal amplification around the upper low
should support some isolated showers along the eastern edge of the
WFO LMK forecast area.
No real significant changes made in the short term from the
previous package. The NAM-WRF and RAP guidance seem to have a good
fit on the convective trends associated with the upper low this
afternoon and this evening.
.Long Term...(Thursday through Tuesday)
Issued at 340 PM EDT Tue Apr 24 2018
An upper level shortwave diving through the Central Plains/Middle
and Lower Mississippi Valley on Wednesday will skirt through the
Tennessee Valley on Thursday. As this shortwave moves southeast,
it will amplify across the southeast U.S., bringing some moisture
and enough instability northward to generate some showers for
mainly the southern 1/2 of central Kentucky mainly Thursday and
Another progressive, but weaker shortwave will follow on the heels
of the aforementioned shortwave (that is forecast to produce
showers on Thursday) leading to a small chance for rain on Friday
afternoon. Any shower development will likely occur during the
peak heating/greatest potential for instability associated with
Beyond Friday, and through the remainder of the forecast period,
large scale high pressure is expected to dominate the region. This
will finally allow the region to dry out and bring temperatures
closer to seasonal normals expected in late April and early May.
In addition to the regionally blended model guidance
initialization, the ECMWF and Canadian numerical guidance was
preferred for the longer range forecast solution with respect to
temperatures and weather.
.Aviation...(00Z TAF Issuance)
Issued at 758 PM EDT Tue Apr 24 2018
Upper level low pressure will slowly make its way eastward, with
plenty of low clouds plaguing the airports into Wednesday morning.
Ceiling heights should mostly start out in the low MVFR ranges below
fuel-alternate, then find their way down to IFR in the pre-dawn
hours. The exception is LEX which will find it`s way down to IFR
shortly after sunset, and possibly down toward minimums through the
Also wanted to mention the fog potential at BWG/HNB toward dawn.
Cloud cover could be thinner in these areas and could promote enough
radiational cooling to promote some fog. Didn`t go as pessimistic as
some of the guidance suggests, but did take conditions a bit in the
Otherwise, conditions slowly improve through the day tomorrow with a
return to VFR possible by late afternoon/early evening. Winds should
be steady out of the NW through this cycle.
Short Term...WFO PAH
Long Term....WFO PAH
Area Forecast Discussion...CORRECTED
National Weather Service Lubbock TX
756 PM CDT Tue Apr 24 2018
A couple things, first strong north winds behind the cold front
are developing another column of counties east of the currently
advised column. We added the column from Castro County southward
through Lamb, Hockley, and Terry Counties. Second, convective
activity continues to develop westward along the frontal boundary.
Short term solutions struggling a bit with this activity.
.PREV DISCUSSION... /issued 653 PM CDT Tue Apr 24 2018/
Nearby strong to severe thunderstorm just east-southeast of KLBB
at the start of this TAF. Solutions agree that activity will pull
gradually east of KLBB but we retained a VCTS at KLBB for a few
more hours. Cumulus field near KCDS and KPVW doesn`t appear
bubbling much and solutions keep convection away for much of the
evening anyway, so removed VCTS for the evening at these sites.
Cold front also moving southward and we timed arrival close to the
latest HRRR trends - a little quicker than the previous set - and
also upped wind speeds. Low cloud deck and increasing showers
coverage later tonight also timed a little more closely to HRRR
trends though this will likely need adjustment by if not earlier
than the next TAF issuance. Mostly MVFR seems favored but deck may
drop near 1000 feet briefly later tonight at both KLBB and KPVW.
So, forecast will try to remain fluid to this quickly changing
environment and we will adjust to the confident trends we see
during the evening. RMcQueen
PREV DISCUSSION... /issued 328 PM CDT Tue Apr 24 2018/
Dynamic weather remains on tap through the night with the
potential for a low end severe event early this evening, gusty
post-frontal winds, and a more widespread precipitation
overnight. The forecast area remains just downstream from a low
amplitude upper level ridge that is centered over New Mexico while
further north from the Great Salt Lake to South Dakota lies an
upper level trough with a closed low at its eastern end near the
South Dakota/Nebraska line. During the next 24 hours or so the
upper ridge will squeezed westward by the upper trough toward a
higher amplitude ridge that will form over the Great Basin toward
southern California. The upper trough/low will rotate to the
south-southeast across the central Plains on Wednesday exiting
toward the lower Mississippi Valley tomorrow evening while
upstream another trough takes shape over the Dakotas.
In the very near term the focus remains on thunderstorm potential
with the possibility of some isolated severe. Surface analysis and
radar imagery clearly showing a low near Brownfield with north
winds to the west and northwest of Lubbock, hot and dry southwest
winds to the southwest of the low and more backed and humid flow
to the east and northeast of the low. The expected convective
temperature of 88F seems to be working out well with elevated
radar echoes developing with cumulus congestus southwest of
Lubbock. CAM`s have been consistent with developing this
convection into thunderstorms as they move into better low level
moisture vicinity Tahoka to Post then progressing it in a general
eastward direction with potential for a northeasterly directed
storm split and potential for supercell development southern
Rolling Plains as indicated by progged Supercell Composite values
in excess of 4 from SPC analysis pages. Isolated strong wind gusts
remain possible particularly early in with the high-based echoes,
transitioning to more of a hail threat as storms hit better
moisture. However, of note is that for now surface moisture is
under-performing relative to the model progs by a few degrees
Fahrenheit. This will have some ramifications on CAPE, but mixed
level values should still exceed 1000 J/kg in this area of
About the time the thunder winds down (02-04Z) a strong cold
front that is located across the northern Texas Panhandle mid-
afternoon will push quickly through the forecast area with 20-30
mph expected. There is a good chance of slightly higher wind
speeds along the NM state line correlated with strongest progged
post-frontal pressure rises. Will issue a Wind Advisory for most
of the night there.
The third issue of the night is additional precipitation
potential. The upper trough/low to our north will move southward
bringing its own mid level moisture with. Model progs support
robust isentropic lift over the frontal surface in advance of the
upper trough. This will lead to increasing showers across the
forecast area, still favoring the eastern half of the forecast
area, but also the possibility of extending toward eastern New
Mexico. Of interest is the amount of elevated instability progged
to develop after 06z with some indications of CAPE in excess of
1000 J/kg supporting the idea of additional thunder late tonight.
Isentropic lift and mid level moisture will move quickly eastward
after sunrise Wednesday with precip ending from NW to SE followed
by clearing in a similar direction later in the morning.
Beyond Wednesday things do not look nearly as dynamic. The next
upper trough mentioned above will drive a cold front into the
region Thursday afternoon or evening, but the window for any
meaningful low level moisture return looks negligible and have
pulled precip mention. Heading into the weekend the upper trough
across the eastern CONUS is replaced by ridging with increased
cyclonic flow across the western CONUS, the Pacific NW initially,
building southward Monday. This pattern will bring the potential
for diurnally-driven dryline type convection possibly as early as
Saturday but with a bit better confidence Saturday through
Wind Advisory until 5 AM CDT Wednesday for TXZ021-022-027-028-
Area Forecast Discussion
National Weather Service Midland/Odessa TX
743 PM CDT Tue Apr 24 2018
VFR conditions are currently present over all of the TAF sites with light
winds out of the south. Expect a cold front to move through around
03z for KHOB and KCNM and later for other sites. Winds will shift
to the north, and low clouds with MVFR conditions are expected behind the front.
Have not included them in the TAFs, but chances for storms will increase
behind the front with MAF and INK having the greatest chance.
Ceilings will improve by 18z and winds will drop off closer to
.PREV DISCUSSION... /issued 316 PM CDT Tue Apr 24 2018/
DISCUSSION...As of 2:45 PM CDT Tuesday...It looks like we will
get four...four letter words weather for the next several days.
We will get some "rain"..."cool" temps..."wind"...and maybe some
"dust" to go along with the wind.
Early this evening we can get some convection firing up along a
weak moisture gradient in the Eastern PB/Low Rolling Plains per
the hi-res HRRR and RAP13. KMAF radar is also showing a few echoes
over the southern mountains. There is the possibility of
strong/severe storms in the northeast CWA...model soundings for
Snyder indc a pretty pronounced inverted V sounding indicating the
possibility of strong/severe winds with any convection. A
shortwave moving thru the Plains will send a strong cold front
thru the CWA tonight. Models are indc strong Gap winds thru GDP
tonight/Wed morning. MOS Guidance usually over forecasts the winds
so knocked them down a bit. Have also issued a Wind Advisory for
the SE New Mexico Plains for the same time period...but it looks
like a marginal event. Regardless...pilots should avoid flying
over the Guadalupe Mountains tonight and Wednesday morning due to
extreme hazardous flying conditions.
Wednesday will be significantly cooler with temps 20-25 degrees
below normal. There is a chance of showers with a slight chc of
thunder tomorrow...best chances in the east. Drier and warmer
weather is in store for the area on Thursday.
For the extended tended to broadbrush the forecast with slight chc
pops Friday into early next week..with temps a little cooler than
normal...warming to a little above normal early next week. The GFS
is wetter with a deeper and faster trof moving thru the Western
US...with a deep southerly flow over the Southern Plains
early/middle portions of next week. The ECMWF is a little slower.
Depending how deep the trof is we might be able to get some low
level return flow from the Gulf the middle of next week...but
that`s a long way off.
.PRELIMINARY POINT TEMPS/POPS...
Big Spring 50 57 43 78 / 50 50 10 0
Carlsbad 50 63 46 85 / 20 20 10 10
Dryden 66 70 49 80 / 30 40 10 0
Fort Stockton 55 60 46 84 / 10 50 10 10
Guadalupe Pass 44 55 47 75 / 10 10 0 0
Hobbs 45 60 44 79 / 30 30 10 10
Marfa 54 59 43 80 / 20 30 10 0
Midland Intl Airport 50 58 44 79 / 50 50 10 0
Odessa 50 58 44 79 / 50 40 10 0
Wink 52 60 46 82 / 30 40 10 10
NM...Wind Advisory from 11 PM this evening to noon MDT Wednesday for
Central Lea County-Eddy County Plains-Guadalupe Mountains
of Eddy County-Northern Lea County-Southern Lea County.
TX...High Wind Warning from 11 PM this evening to noon MDT Wednesday
for Guadalupe Mountains.
Area Forecast Discussion
National Weather Service Marquette MI
757 PM EDT Tue Apr 24 2018
.SHORT TERM...(This evening through Wednesday)
Issued at 400 PM EDT TUE APR 24 2018
...Generally quiet weather in short term...
WV imagery and RAP analysis indicated a split flow pattern with an
upstream northern stream shortwave trough from nw Ontario into
northern MN. At the surface, a cold front extended from northern
Ontario into western Lake Superior and central MN. Mid-high clouds
have been on the increase this afternoon across Upper Michigan ahead
of the shortwave and associated cold front. A few sfc obs over east
central MN and nw WI have reported isolated showers/sprinkles along
the front. With a northerly flow across the area temps have been
cooler today ranging from the mid 40s west to the lower to mid 60s
Tonight, Maintained slight chance pops late afternoon/this evening
as forcing from the passing shortwave and associated cold front work
across the area, but again shower coverage will be isolated with
only light precipitation expected as model soundings show dry low
levels in place. Model soundings suggest that skies will clear from
west to east during the evening with drier air moving in. However,
upslope northerly flow aided by some lake moisture could support
some stratocu clouds north central late.
Friday, Cold advection upslope northerly flow will continue to
support some lower clouds into north central counties in the
morning, but otherwise expect mostly sunny skies. With continued
northerly flow expect highs ranging from around 40F near Lake
Superior shore to lower to mid 50s south central and interior west.
Daytime minimum RHs could lower close to 20 pct over the interior
west along the WI border, but with fairly light winds and relatively
cool temps expected, fire weather concerns should be minimal.
.LONG TERM...(Wednesday night through Tuesday)
Issued at 222 PM EDT TUE APR 24 2018
The next week or so looks to be our version of spring before we
swing into a summer-like pattern with highs in the upper 60s to
lower 70s with periodic chances for precipitation (dare I say
thunderstorms?) However, we`ll have to get through couple of days
of colder temperatures and maybe even some light snow before
pulling out the shorts.
First thing is first...A cold front is expected to swing through the
upper Great Lakes Thursday afternoon and evening ushering in
relatively colder air compared to the past few days. Numerical model
guidance paints anywhere from a trace to 0.25" of QPF along the
front with the GFS most "heavy." Given antecedent conditions (as
well as the mostly dry cold front coming through today), the
inclination is to keep qpf low--generally less than 0.05" area
wide. As for precipitation type, light rain is expected to
transition to light snow (if not heavy flurries) as colder and
drier air filters in along the backside of the front. No snow
accumulations are expected. The biggest impact of the frontal
passage will likely be strong north to northeasterly winds gusting
over 30-35 mph Thursday evening and into early Friday morning
across the west and north central shores of Lake Superior.
Temperatures are expected to reach the upper 50s to lower 60s
before the front sweeps though.
A secondary shortwave trough and associated compact low pressure
system will sneak into the area Friday with a narrow ribbon of
anywhere from a 0.05" to 0.15" of QPF. Earlier model runs indicated
mainly light rain along the northwestern side of the low but 850 mb
temperatures/max wet bulb temperatures may hover at if not just
below freezing leading to a mix of rain and snow. To make matters
a bit more complicated, forecast soundings indicate a layer of dry
air (max dew point depressions of 11 C or so) from about 850 mb
down to the surface as the main forcing from the low passes
through. All in all, there is low confidence in just how much
precipitation will make it to the ground. As such, kept QPF fairly
low in the grids for now to give time to iron out the details.
Saturday looks quiet and dry with highs in the forties along the
Lake Superior shore to lower fifties along the Wisconsin border.
The real warm up begins on Sunday as deep upper-level ridge builds
into lower central Canada enabling broad southwesterly low- to
mid- level flow across the western Great Lakes. Monday and Tuesday
look quite warm with 850 mb temperatures shooting up to +10-12 C,
giving way to highs in the low to mid 70s (if not warmer) and
lows in the lower 40s. Model guidance also depicts dew points
increasing quite a bit owing to the aforementioned southwesterly
flow. By and large the warmer and moister conditions will start
the vanishing act of the remaining snowpack across Upper Michigan.
The big question is just how long the upper-level ridge will last
(especially for fire weather concerns). A quick peak at a
northern hemispheric perspective of the forecast upper-level flow
next week reveals that a pair of cut-off lows off the western and
eastern CONUS *should* keep the wave train moving aided by a
shortwave trough in between. However, it would not be surprising
for the ridge to move slower than currently depicting in the
models (as they often do). Even so, when the shortwave trough
embedded in the longwave pattern pushes into the Great Lakes, the
expectation is that at least portions of the area may get in on
heavier precipitation which, when combined with snow melt, may
cause some minor river flooding problems. Stay tuned.
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 756 PM EDT TUE APR 24 2018
Band of -ra following a cold front will pass across KSAW in the next
hr, but not expecting conditions to fall out of VFR. Satellite
imagery reveals stratocu extending nw across Lake Superior into
adjacent northern Ontario. These clouds will pass across KCMX this
evening and probably KSAW late tonight/Wed morning. Cloud bases are
likely to range from 3500-5000ft, but there is a small chance MVFR
cigs could occur at KSAW. Under a dry air mass, VFR conditions will
prevail at all terminals during the day Sun.
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 400 PM EDT TUE APR 24 2018
Northwest winds will increase to 20-25 knots over central and
eastern Lake Superior late this afternoon into this evening and then
diminish overnight. Wednesday through Thursday, winds are expected
to remain below 20 knots across all of Lake Superior. Winds will
then pick up to 20 to 30 knots Thursday night with the passage of
another cold front.
Issued at 222 PM EDT TUE APR 24 2018
After a 24-hour period of highs in the lower 70s and lows in the low
to mid 30s (e.g. above freezing), the snow pack has lost 3-5 inches
across much of Upper Michigan. The snow pack will continue to melt
today but at a slower pace mostly driven by the sun (when not
blocked by clouds). Most rivers across Upper Michigan have seen
manageable rises in water levels thus far, except for a minor ice
jam reported on the Ford river in Escanaba that has since broken
apart. Precipitation chances over the next several days look
somewhat bleak (collectively less than 0.25"). However, temperatures
next week will increase dramatically with an accompanying increase
in moisture likely leading to a rapid decrease in snow cover
across the area. There are indications of heavier precipitation
toward the middle to end of next week, though uncertainly remains
on exactly where and how much will fall. All in all, the snow pack
is expected to shrink considerably next week which may lead to
minor river flooding in the usual rivers prone to spring flooding.