Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/16/20
Area Forecast Discussion
National Weather Service Bismarck ND
930 PM CDT Fri May 15 2020
.UPDATE...
Issued at 926 PM CDT Fri May 15 2020
With this update we blended 00Z HRRR guidance into the going
forecast to bump precipitation chances up slightly in areas along
the South Dakota border. Confidence in chances further north is
low as the mid-level low is forecast to stay well into the South
Dakota side. Otherwise current radar and lightning detector trends
show coverage of showers is on its way down in the southwest with
no recent sign of lightning. Water vapor imagery shows the next
shortwave making its way into central Wyoming, with at least
several more hours to go before associated ascent and
precipitation will increase along our south.
UPDATE Issued at 632 PM CDT Fri May 15 2020
Scattered showers and a few thunderstorms continue for areas
generally south and west of the Missouri River, centered on
Stark/Hettinger counties. Aloft a subtle shortwave trough was over
northwest South Dakota while a deeper trough was just upstream
over western Wyoming. As the upstream trough begins to dig
slightly southeast by early Saturday morning, ascent should remain
over areas along the ND/SD border. But while loss of daytime
heating and the progressively weaker support from the first
shortwave should decrease precipitation coverage this evening,
recent runs of the HRRR continue showers in the southwest through
the overnight hours as DCVA from the next wave increases. Low-mid
level forcing mechanisms look rather weak and instability sparse
so we refrained from adjusting PoPs upward for now...but this will
need to be reevaluated in the next forecast update.
&&
.SHORT TERM...(This evening through Saturday)
Issued at 316 PM CDT Fri May 15 2020
The main issue in the short term period will be shower and
thunderstorm chances.
Currently, showers were located from around Dickinson, west to
around Beach and then west and south to Glendive and Baker
Montana. The showers in North Dakota are along an area of surface
convergence within an area of weak Cape (around 250-500 J/KG) and
no deep layer shear, but steep low level lapse rates. This weakly
unstable airmass will remain through early to mid evening. With a
weak mean flow, those that do see some showers or possible thunder
could see some locally decent rainfall amounts.
Overall, we trended lower and farther south with the precipitation
tonight and into Saturday, keeping the best chances right along
the ND/SD border as an upper level wave tracks across South
Dakota. The widespread lower 30s and upper 20s we experienced
this morning will be replaced by overnight lows mainly in the 40s.
Some upper 30s are possible along the International Border, and
possibly the southwest if they clear out late tonight.
Saturday will be dry for most, with seasonable cool temperatures
in the mid 50s along the SD border, to around 70 near the Canadian
border. We will maintain some chance pops in the far south. A few
diurnally driven showers are possible mainly west of the Highway
83 corridor Saturday afternoon.
.LONG TERM...(Saturday night through Friday)
Issued at 316 PM CDT Fri May 15 2020
Warm early then Thunderstorm chances increase by mid week.
An upper level ridge builds over the area in the wake of the
exiting SD upper wave, bringing warming temperatures to start the
week. The latest blended guidance is giving mid 80s in the far
west on Monday with 70s for the rest of the forecast area. The
ridge axis slides east late Monday as a strong Pacific low pushes
onshore. Well above average temperatures in the 80s and lower 90s
are expected for Tuesday, with precipiation chances entering the
forecast Tuesday evening. Instability will be on the increase, so
the threat for strong to severe convection will be possible, but
there may also be some capping issues Tuesday for portions of
the area. The deep low is expected to push over the Rockies
mid-week and gradually lift into the northern Rockies, though the
timing and exact placement remains in question. Nonetheless, an
unsettled pattern remains over our area, keeping rain chances
through the remainder of the extended period.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 632 PM CDT Fri May 15 2020
Showers and a thunderstorm possible at KDIK through this evening
and then MVFR cigs expected Saturday morning. VFR conditions
expected at other sites through the TAF period.
Showers and an isolated thunderstorm or two continue this evening
in the vicinity of KDIK, though it appears most activity has been
avoiding the airport so far as convection has slowly shifted off
to the southeast. Kept -SHRA and VCTS in the TAF until 02Z with
radar indicating precipitation very near the airport at the
beginning of the TAF period. Cloud cover will increase along the
south, introducing MVFR cigs into KDIK by 12Z. This cloud cover
should stay further south in areas east of KDIK like KBIS-KJMS,
which were kept VFR in the TAFs. VFR also expected at other
terminals across western and central North Dakota.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AE
SHORT TERM...TWH
LONG TERM...TWH
AVIATION...AE
Area Forecast Discussion
National Weather Service Gray ME
1126 PM EDT Fri May 15 2020
.SYNOPSIS...
Low pressure over upstate New York will track across southern
New Hampshire and the southern tip of Maine spawning widespread
showers and thunderstorms this evening. Along and south of the
low track will be the area most likely to see thunderstorms
containing large hail, damaging winds and heavy rainfall. The
low will race offshore tonight with high pressure and drier air
to follow for Saturday and Saturday night. Low pressure will
approach from the west late Sunday, before slipping south of the
region early next week.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
1125 PM...Update to add fog to the forecast. Plenty of low
levell moisture in place and a weak gradient for most of the
night may lead to dense fog in some areas.
955 PM Update...
A few changes to the forecast based on current trends.
655 PM Update...
Straight-line wind damage appears to be about to occur in
southern NH at the moment. Nice bowing segment is moving east
quickly into far southern NH. To the north, we are seeing
scattered rain showers. Expecting some lightning/thunder across
southern NH and SW ME over the next 1-3 hrs. Minor changes to
the forecast database for this update; and will keep with severe
wording over southern NH.
At 18z a 1008 millibar low was centered over eastern Lake
Ontario with a warm front extending eastward through southern
and western New England. The trailing cold front extended
through the lower lakes and upper midwest. NWS Doppler Radar
mosaic showed an area of showers across eastern Ontario and
southern Quebec that will cross the mountains through central
Maine this evening as that area remains mired in the cooler and
more stable air north of the warm front. Further south...an
area of blossoming convection was developing across the lower
lakes and nearby upstate New York in response to strengthening
wind field and increasing instability ahead of shortwave
impulse. Through this evening...CAMS brings a broken line of
convection into New England by early evening with the best
chance for strong and severe convection largely limited to
western and southern New Hampshire and perhaps the southern tip
of Maine with damaging wind gusts the primary threat. However...a
few of the strongest cells could produce some marginal severe
hail as well. The HRRR trend over the past several hourly runs
has been to shift the strongest convection and best stability a
bit further south and west in our CWA. In any event...this will
be a short-lived event with most guidance having the bulk of
the convection offshore by late evening...with only a few
lingering showers across northern and eastern sections
overnight. I expect some patchy fog and stratus to develop
overnight as well.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
On Saturday, a weak area of high pressure will build in from
the north. Partial sunshine is expected along with temperatures
slightly above normal with 60s most areas...except for a few low
70s over southern interior New Hampshire. Partly cloudy under
the ridge Saturday night with lows in the 40s.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
The upcoming pattern portends to unsettled weather into
Midweek. With amplified trough and eventually potential closed
low to our south we expect rain chances to increase Sunday night
and especially Monday. Thereafter, continued unsettled weather
is expected, but the degree of which is uncertain at this time
because there is uncertainty in the disposition of upper level
low pressure and the increasingly blocky pattern.
&&
.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
Short Term /Through Sat night/...Areas of MVFR developing in
SHRA by evening with sct strong to severe TSRA possible along
and south of a KLEB to KSFM line through 01z Sat. Overnight...
lingering areas of MVFR cigs and isold -SHRA with lcl IFR psb in
fog. Becoming VFR throughout aft 12z Sat.
Long Term...VFR on Sunday gives way to MVFR Sunday night and IFR
by 12z Monday as low pressure approaches and spreads low clouds
and rain in our direction. These lower conditions can be
expected at least through Tuesday.
&&
.MARINE...
Short Term /Through Saturday Night/...Winds and seas expected to remain
below SCA thresholds through the period. However...behind the exiting
surface low overnight there could be a brief surge of winds with
gusts approaching 25 kt.
Long Term...Slow moving low pressure is likely to bring an
increase in winds and seas Sunday night and Monday which will
continue right through midweek.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.
&&
$$
JC/MC
Area Forecast Discussion
National Weather Service North Platte NE
640 PM CDT Fri May 15 2020
.SHORT TERM...(This evening through Saturday night)
Issued at 318 PM CDT Fri May 15 2020
A midlevel cold front has been the focus for showers this morning
across swrn Nebraska. The front will lift northwest into the
Sandhills and northwest Nebraska and become the focus for heavy
rainfall across much of western and north central Nebraska tonight
and Saturday.
Upper level dynamics wrn WY this afternoon will move progressively
east tonight and Saturday and the models show either a closed
compact h700mb low or sharp h700mb trof forming across swrn
Nebraska. The main forcing will be across SD and the models are
suggesting 1 to nearly 2 inches of rainfall across parts of SD and
Neb. The system will be competing for moisture with storms forming
over wrn KS and OKLA tonight. This could disrupt moisture transport
into Nebraska and lessen rainfall amounts.
The rain forecast follows the short term model blend and WPC for
likely to definite POPs tonight. Given the progressive motion of the
storm system (east at 20 mph) and the potential for a dry air
intruding from the storms across the midsouth, the prospect of
excessive of rainfall is uncertain. 3 hour FFG values are 2 inches
or less across swrn Nebraska so there is some concern for at least
minor flooding.
The severe weather potential appears to be very modest. The warm air
advection will have to come across the Rockies and Laramie range.
The preferred location is ern Colo directed at the Neb Panhandle or
swrn Neb but sfc winds across ern Colo will be backed to the east
and southeast preventing warm air from surging north up the high
plains. The RAP model shows a dryline bulge approaching Pine Ridge
this afternoon and this is probably the reason the models show storm
genesis in that area. There is also an inverted trof in that area
for moisture focus. Winds aloft at h500mb are strong at 30-40kts
supporting strong shear and moisture is plentiful. Lapse rates
should be steep initially across wrn Nebraska but Bufkit shows
moisture and moist adiabatic lapse rates overwhelming the soundings.
The HRRR suggests a developing linear thunderstorm complex driven by
a robust cold pool and instability sufficient for maintenance.
.LONG TERM...(Sunday through Friday)
Issued at 318 PM CDT Fri May 15 2020
A fairly strong piece of Canadian high pressure will build into
the wrn and ncntl Nebraska in the wake of the exiting storm
Saturday. This high will move off east Sunday and Monday with
modest warming commencing Monday. There is very little change in
the forecast highs Sunday or Monday.
Sfc low pressure will form on the nrn high Plains Tuesday and remain
in place Wednesday. These two days should be the warmest days next
week with highs in the upper 70s to upper 80s. The model blended
forecast suggests a Pacific cold front Wednesday night will be the
focus for thunderstorms across wrn Nebraska. The front will stall
across ncntl Nebraska Thursday and isolated thunderstorms are in
place Thursday and Friday. No big cool down is expected behind the
front.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 639 PM CDT Fri May 15 2020
Showers and thunderstorms were numerous from the southern Nebraska
panhandle into the central Sandhills north of Mullen. This area is
expected to persist and move eastward near 20 mph. This is
expected to reach the KLBF terminal between 04Z and 05Z.
Visibility from heavy rain could lower to 2SM or less with wind
VRB20G30KT. This should move east of the KLBF terminal by 09Z.
After 09Z, an IFR ceilings and 3SM visibility should persist until
15Z. Thereafter, ceilings should improve to MVFR, then VFR after
20Z. At KVTN, -SHRA possible at times until 06Z, followed by an
MVFR ceilings lowering to IFR 12Z to 20Z, then to MVFR through end
of TAF period.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Roberg
Area Forecast Discussion...Updated
National Weather Service Saint Louis MO
945 PM CDT Fri May 15 2020
.UPDATE...
Issued at 944 PM CDT Fri May 15 2020
Latest surface analysis showed that the cold front has moved to
the Missouri/Arkansas border with light winds across the CWA.
Showers and thunderstorms have moved into Kentucky, so backed
down on PoPs across the CWA until late tonight when the RAP shows
an increase in low level moisture convergence over the area in
weak southerly flow. Satellite imagery showed extensive convective
debris clouds streaming from thunderstorms over the Southern
Plains, though there has been some recent thinning. Can`t rule out
some patchy fog developing overnight given the light winds and
moist boundary layer. Made only minor adjustments to going lows
based on observations.
Britt
&&
.SHORT TERM... (Through Late Saturday Night)
Issued at 355 PM CDT Fri May 15 2020
Atmosphere remains rather stable over the region from the early
morning activity today. So focus shifts back to the stalled frontal
boundary that is near the MO/AR border as of 20z. It will become a
warm front and begin to slowly lift northward towards the forecast
area late tonight. In the meantime, with light winds and plenty of
low level moisture, could see some patchy fog develop, especially
across portions of southeast Missouri. Added mention after 06z
Saturday. Other issue is the chance for isolated showers and perhaps
a clap of thunder, so kept slight/low chance pops along and south of
I-70.
On Saturday the warm front will slide northward through the region
in response to the approaching upper level system from the west and
backing flow aloft. Expect scattered showers and a few storms during
the morning hours with this boundary, then focus then shifts to warm
sector south of the warm front. ML CAPES between 500 and 1000 J/kg
are expected by the afternoon with weak shear (around 10 to 15 kts),
but still sufficient enough for isolated severe storms, mainly along
and north of I-70 during the afternoon and evening hours. SPC has
placed this area in a marginal risk with the main threats being
large hail and damaging winds.
Saturday night, main cold front will begin to slide through region
with showers and thunderstorms likely across the region.
Lows will be a bit above normal tonight in the mid 50s to mid 60s.
Highs on Saturday will be warmer, in the mid 70s to low 80s, then
lows Saturday night will be in the upper 50s to mid 60s.
Byrd
.LONG TERM... (Sunday through Next Friday)
Issued at 355 PM CDT Fri May 15 2020
Showers and storms likely Sunday morning as cold front moves
through. Then activity will taper off by early Sunday evening as
surface ridge builds into region. So dry weather expected for the
remainder of the forecast period. As for temperatures, the synoptic
set up remains favorable for an omega block pattern that will keep
the region in the northwest flow aloft, so temperatures will be near
or slightly below normal through most of the work week, before
temperatures begin to moderate once again.
Byrd
&&
.AVIATION... (For the 00z TAFs through 00z Saturday Evening)
Issued at 646 PM CDT Fri May 15 2020
Dry and VFR conditions are expected through late tonight. Some fog
is expected to develop over southeast Missouri with MVFR or IFR
conditions. MVFR ceilings will develop at the terminals after 12Z
on Saturday morning, but rise above 3000FT by late morning.
Scattered showers and thunderstorms will move into the area during
the morning hours, and they will become more numerous during the
afternoon.
Britt
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Marquette MI
738 PM EDT Fri May 15 2020
.SHORT TERM...(This evening through Saturday)
Issued at 400 PM EDT FRI MAY 15 2020
WV imagery and RAP analysis indicated a mainly zonal pattern through
the northern CONUS. The compact mid level low or shortwave that
brought shra/tsra through the Keweenaw and eastern Lake Superior was
exiting to the east of Lake Superior. THe next significant
upstream shrtwv was moving through the northern Rockies. High
pressure from northern Manitoba into nw Minnesota was building
into the area bringing northerly flow through Upper Michigan.
Diurnal heating and mixing has helped to bring some clearing with
mainly sct/bkn cu developing.
Tonight, mid level and surface ridging building into the areas with
light winds and mostly clear skies will allow temps to drop into the
mid to upper 30s. With afternoon dewpoints still in the low to mid
40s, expect some fog to develop, especially over the northwest and
east.
Saturday, partly cloudy skies in the morning will give way to
increasing mid/high clouds as WAA/isentropic lift develops ahead of
the mid level trough moving through the northern Plains. An area of
rain associated with strengthening mid level fgen may bring some
pcpn into the far west late. However, the initial band of rain may
be slowed by the low level dry air over Upper Michigan where
afternoon dewpoints in the mid 30s are expected. Expect enough
sunshine to boost temps into the mid 50s inland while readings
remain in the lower to mid 50s along the Great Lakes.
.LONG TERM...(Saturday night through Friday)
Issued at 357 PM EDT FRI MAY 15 2020
Overall, Saturday night/Sunday will be a soggy end to the weekend
with widespread chances for rain. Models still are not in the best
agreement with overall rainfall amounts, but confidence is highest
across the south-central for locations to pick up around 1-2 inches
of rain. Early through middle parts of next week, upper-level
ridging becomes highly amplified across the central CONUS and upper
Great Lakes as a weak omega block develops across the lower 48. This
blocking pattern will allow Upper Michigan to remain under the
influence of persistent warm air advection and above-normal
temperatures next week.
Saturday night through Sunday, shortwave energy will track across
the western Great Lakes, with the associated surface low tracking
across southern parts of Wisconsin and lower Michigan. As warm air
advection and isentropic lift increase, widespread rain is expected
to lift into the area late Saturday night, pivoting across the area
and lingering through much of Sunday. As noted above, confidence is
highest for locations across the south-central to pick up 1-2 inches
of rain. However, given the system`s track and northeast 850mb flow
persisting across the region as the main 850mb low tracks south of
the Upper Peninsula, locally enhanced rainfall amounts are expected
across the higher terrain across the west and north-central. While
warmer conditions aloft should keep the low-levels more stable, 40-
50 knots of shear just off the surface should occasionally mix down
with the expected rain activity. Thus, did boost wind gusts up into
the 20-30 mph range. This wind direction and enhanced onshore over
Lake Michigan may cause some concerns for lakeshore flooding along
the southern shoreline of the Bay of Green Bay.
Monday and Tuesday, high pressure from Canada drops south across the
Upper Great Lakes bringing a drying trend to the region. Forecast
soundings show impressive low-level drying so did end up adjusting
dew points down quite a bit to reflect these expected conditions.
Thankfully, we will see some widespread rain leading into these
drier conditions, as temperatures look to climb into the 60s and 70s
for much of the area.
The dry weather continues through middle parts of the week, with a
warming trend as upper-level ridging remains amplified across the
region and a deep trough over the central and northern Rockies ever
so slowly moves east into the northern Plains. This pattern will
favor strengthening 850mb flow and increasing warm air advection.
Still no precipitation concerns until Friday, but temperatures do
look to climb 15-20 degrees above normal for this time of year.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 738 PM EDT FRI MAY 15 2020
VFR conditions should largely prevail at KIWD/KCMX/KSAW thru this
fcst period. However, as winds become light/calm tonight with high
pressure arriving and since some low-level moisture lingers, fog may
develop. If fog develops, it`s uncertain how dense the fog may
become. For now, only included MVFR vis in fog at KCMX overnight,
but not out of the question that fog could develop at KSAW as well.
Any fog that develops will quickly burn off within a couple of hrs
of sunrise.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 400 PM EDT FRI MAY 15 2020
Some patchy fog over mainly the southern end of the lake is expected
to persist into the early evening. As high pressure builds in and
that moisture becomes trapped some fog may redevelop tonight and
possibly into Saturday. However, given afternoon satellite trends,
expect that the probability of additional widespread dense fog is
low. Winds should generally remain light through Saturday. Low
pressure passing to the south of Upper Michigan is expected to boost
northeast winds to around 25 knots Sunday. Otherwise, winds should
remain below 20 knots into next week.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
Dense Fog Advisory until 11 PM EDT this evening for LSZ242>244-
250-251.
Lake Michigan...
None.
&&
$$
SHORT TERM...JLB
LONG TERM...Ritzman
AVIATION...Rolfson
MARINE...JLB
Area Forecast Discussion
National Weather Service Pueblo CO
247 PM MDT Fri May 15 2020
.SHORT TERM...(This evening through Saturday)
Issued at 247 PM MDT Fri May 15 2020
Currently...radar indicates shower activity developing from the La
Garita range, northeast into the Palmer Divide region, as well as
the southern I-25 corridor early this afternoon. Temperatures are
pleasant, with lower to mid 70s across the lower elevations. Winds
are southeasterly across the Plains helping to keep moisture pooled
across the Plains.
Rest of today...as mentioned, southeasterly winds and slowly
eroding stratus clouds have allowed moisture to remain pooled
across the Plains and limiting mixing for this afternoon. Dewpoints
are in the mid to upper 40s across much of the Plains. This has
allowed for CAPE values to climb above 1000 j/kg, and should
increase to near 1500 j/kg over the next couple of hours. The
latest HRRR has shifted the 0-6km bulk shear max a bit further
south, mainly along and north of Highway 50. High-res model
guidance has 0-6km shear around 40 to 45 kts. Energy embedded in
the westerly flow should help to trigger showers and thunderstorms
this afternoon. Based on the high-res model consensus, the greatest
risk of severe thunderstorms looks to be east of I-25 and north of
Highway 50 through this evening. Shear and CAPE profiles should
promote sustained updrafts and organized convection. Stronger
storms will be capable of producing hail in excess of 1 inches in
diameter and wind gusts near 60 mph along with lightning. South of
Highway 50, convection will be more isolated to scattered. CAPE
values over 1500 j/kg should support strong updrafts, however,
weaker shear values may limit severe potential, although one or two
may be possible.
Tonight...expect thunderstorm activity to shift east across the
Plains through the overnight hours, exiting into Kansas by Saturday
morning. At the surface, a weak cold front will drop south behind
the departing thunderstorms through the morning. Overnight lows
will remain mild with 40s to lower 50s across the region.
Saturday...upper level ridging over the Intermountain West will
shift eastward through the afternoon. At the surface, low level
flow will shift southeasterly over the Plains. Showers and
thunderstorms are expected by the afternoon hours, initiating over
the Mountains, and spreading into the Palmer Divide and Raton Mesa
by the evening. Given the lack of shear and energy moving across
Colorado, thunderstorm coverage will be less, with isolated to
scattered activity through the evening. Lightning, hail to near an
inch and gusty outflow winds to near 50 mph are all possible.
Mozley
.LONG TERM...(Saturday night through Friday)
Issued at 247 PM MDT Fri May 15 2020
Saturday Night and Sunday:
A frontal passage earlier in the day, visible via surface pressure
fields, will shift winds to the northeast, which is a favorable
orientation for upslope flow over the eastern mountains. There will
be around 600 to 700 J/kg over the southeast mountains. Model
guidance agrees with the outcome and has continuously indicated that
some heavier rain will fall Saturday evening over the eastern
mountains. With the CAPE in place and the QPF remaining over the
mountains, there will be a flash flood risk in place over the Spring
Burn scar during Saturday evening.
Sunday morning and early afternoon will remain relatively quiet as
500hPa heights increase throughout the day. MSLP fields indicate a
tight gradient forming over the plains, which will advect moisture
from the south. In the mid afternoon, the moisture will reach the
Palmer Divide and a weak shortwave trough will propagate over
southern Colorado. The combination of the two will spark
thunderstorms over the Palmer and the storms have the potential to
become severe. There will be around 1200 J/kg of CAPE present and
around 25 to 35 kts of 0-6km bulk shear. Looking at the
thermodynamic profile, the cloud bases will be higher, so the main
risk potential will be for strong winds, around 60 mph, and isolated
quarter sized hail.
Monday:
Southwesterly flow aloft returns to southern Colorado increased
critical fire weather potential for the San Luis Valley and the I-25
corridor. The temperatures on Monday will be quite warm with high
temperatures over the plains expected to be in the mid 90s and the
mountain valleys in the mid 80s. Precipitation potential seems
minimal, but there may be an isolated shower and thunderstorm over
the mountains.
Tuesday through Friday:
A closed low is forecast to travel towards southern Colorado on
Tuesday and Wednesday. Some Pacific based moisture is expected to
reach Colorado on Tuesday afternoon, which is expected to bring
widespread showers and thunderstorms over the mountains. There will
be around 500 J/kg of CAPE over the mountains, so the instability
values aren`t too high. Even with the lower CAPE values over the
mountains, there is still a potential for flash flooding over the
Spring, Decker, Hayden Pass, and Junkins burn scars on Tuesday
afternoon.
The upper low propagates over central Colorado on Wednesday and
there will be the potential for thunderstorms over the far eastern
plains, as a dryline sets up. Model guidance is mixed about what
will occur, but the impacts seem minimal at this point. There are
some major timing issues of when the closed low will propagate over
Colorado, which will also throw a wrench in thunderstorm
development. At this point in time, there is a low risk for storms
over the far eastern plains.
On Thursday and Friday there will be lee cyclones developing over
the eastern plains, which could set up a dryline over the far
eastern plains, but the models are resolving the main moisture plume
to be in Kansas on both afternoons.
Enhanced potential for critical fire weather conditions will be in
place over the San Luis Valley, the upper Arkansas River Valley, and
parts of the eastern plains from Tuesday through Friday afternoons.
A jet streak forms over the region on Wednesday, Thursday, and
Friday, which puts the "best" fire weather conditions during those
afternoons.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 247 PM MDT Fri May 15 2020
KALS...VFR conditions through the next 24 hours with passing mid and
high clouds into this evening. A few wind gusts to near 20 to 25
kts are possible this afternoon.
KCOS and KPUB...showers and thunderstorms will be possible at both
terminals this afternoon and evening. Reduced CIGS and VIS will
accompany thunderstorms that move over the terminals. A weak cold
front will drop south at the terminals tonight, with low stratus
possible into Saturday morning. Isolated thunderstorms may be
possible on Saturday afternoon. Mozley
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MOZLEY
LONG TERM...SKELLY
AVIATION...MOZLEY
Area Forecast Discussion
National Weather Service Tulsa OK
935 PM CDT Fri May 15 2020
...UPDATE...
.DISCUSSION...
Daytime MCS has worked over the atmosphere across most of
the forecast area, with some lingering instability noted
across far southeast OK. In light of recent HRRR runs,
have lowered PoPs and thunder chances the remainder of
the night.
Updated products have been sent.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 64 78 62 77 / 20 70 50 0
FSM 66 78 65 78 / 30 80 80 30
MLC 64 76 64 78 / 40 80 60 10
BVO 63 78 59 76 / 20 70 40 0
FYV 63 76 62 74 / 20 80 80 30
BYV 62 75 62 73 / 20 80 80 40
MKO 64 77 63 77 / 30 70 60 10
MIO 63 77 60 74 / 20 60 60 0
F10 64 76 62 77 / 30 70 50 10
HHW 66 75 65 79 / 50 80 60 20
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...None.
AR...None.
&&
$$
SHORT TERM...18