Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/15/16
Area Forecast Discussion
National Weather Service Tucson AZ
340 PM MST SAT MAY 14 2016
.SYNOPSIS...
Expect isolated showers and thunderstorms mainly east of Tucson this
evening. Gusty southwest winds will occur Sunday afternoon as a
storm system moves north of the area. Otherwise, dry conditions with
a cooling trend will prevail Sunday into Monday. A slight chance of
showers and thunderstorms exists Tuesday and Wednesday as the next
storm system strengthens north of the area.
&&
.DISCUSSION...Scattered showers were occurring generally northeast
of a Picacho Peak-Tucson-Sonoita line at this time. Rainfall amounts
from a few rain gauges have been mostly less than 0.10 inch. 14/12Z
NAM/GFS/ECMWF/CMC and the Univ of AZ WRF-NAM and WRF-GFS depict
these showers and a few thunderstorms to decrease in coverage fairly
quickly early this evening.
Have maintained a slight chance of showers across the White
mountains late tonight. Otherwise, dry conditions will prevail thru
Monday evening as deeper moisture is shunted well east of this
forecast area in response to strengthening wly winds aloft. A tight
mid-level gradient will provide gusty southwest winds Sunday
afternoon. A wind advisory is in effect from noon to 7 PM MST Sunday
for locales southeast of Tucson, especially near the International
border. Still some gusty swly/wly winds Monday afternoon, but speeds
will be below wind advisory criteria.
GFS/ECMWF/CMC were similar with deepening an upper trough over the
Great Basin/Intermountain west/southwestern CONUS Tue-Wed. Although
the bulk of deeper moisture is progged to be north and east of this
forecast area, there appears to be enough moisture to justify at
least a slight chance of showers/tstms east of Tucson Tue-Wed night.
A drying trend should commence Thur as the mid-level trough axis
moves east of the area. Still enough moisture for a chance of
showers/tstms across the White mountains Thur. Dry conditions are
then expected Thur night-Sat under wly/swly flow aloft. Breezy to
windy conditions may occur next Sat as the mid-level gradient
tightens ahead of a deepening upper low pressure system over the
Pacific NW/Great Basin region.
A cooling trend will occur Sun-Tue, then daytime temps will average
about 5 degs or so below normal Tue-Wed. A warming trend is forecast
to prevail Thur-Sat, with high temps trending a few degs above
normal late next week.
&&
.AVIATION...VALID THRU 16/00Z.
Sct-bkn clouds aoa 8k ft with cirrus above thru this evening then
clearing skies late tonight. Clear skies to sct clouds above 20k ft
agl Sunday. Isold-sct -TSRA/-SHRA persisting thru mid-evening,
mainly east/southeast of KTUS. Swly sfc wind at 10-18 kts with gusts
to 25 kts, with the strongest surface wind east of KTUS in the
vicinity of KALK, KFHU and KDUG. Wind speeds diminishing after
sunset to generally less than 10 kts. Sly/Swly winds will increase
once again late Sunday morning, with speeds during the afternoon of
15 to 25 kts with gusts to 35 kts. Strongest winds will again be
nearest the International border areas. Aviation discussion not
updated for TAF ammendments.
&&
.FIRE WEATHER...There is a slight chance of showers and thunderstorms
from the Tucson area eastward through this evening. Any storms that
do develop will have the potential to produce gusty and erratic
winds. Otherwise, 20-ft winds will be out of the southwest this
afternoon at 10 to 15 mph with a few higher gusts. Less wind is
expected overnight tonight into Sunday morning.
Drier air will settle in Sunday along with gusty southwest winds.
The southern portions of Fire Weather Zones 151 and 152, as well as
the Galiuro and Pinaleno Mtns are expected to reach critical fire
weather conditions Sunday afternoon. Therefore, a Red Flag Warning
has been issued for these areas from late Sunday morning into early
Sunday evening.
Daytime temperatures will hover within a few degrees on either side
of normal Monday into next weekend. The next chance for showers or
thunderstorms will be east to northeast of Tucson from Tuesday into
Thursday. Afternoon breeziness from the west or southwest is likely
through next week, with the strongest winds nearest the
International border.
&&
.TWC Watches/Warnings/Advisories...
Red Flag Warning from 11 AM to 7 PM MST Sunday for AZZ151-152.
Wind Advisory from noon to 7 PM MST Sunday for AZZ507-508-512-
513.
&&
$$
DISCUSSION...Francis
AVIATION/FIRE WEATHER...French
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
[top]
Area Forecast Discussion
National Weather Service Phoenix AZ
326 PM MST SAT MAY 14 2016
.UPDATE...
Updated Aviation and Fire Weather sections.
&&
.SYNOPSIS...
High pressure over the region is starting to weaken and shift
eastward. This signals a change to slightly cooler temperatures and
more breezy conditions for the weekend. Another Pacific weather
system is forecast to move into the western states, including parts
of Arizona late Sunday through Tuesday. This will provide even
cooler temperatures along with slight chances of thunderstorms mainly
over northern and central Arizona. Clearing skies with rebounding
afternoon temperatures are forecast for late next week.
&&
.DISCUSSION...
Latest satellite imagery shows several areas of cumulus congestus,
mainly concentrated across the Mogollon Rim, the CO Plateau and
portions of southeastern AZ. Isolated showers and thunderstorms have
developed, but are mainly relegated to the higher terrain near
Tucson and Flagstaff. Meanwhile, moisture values are running well
above average with dewpoints in the mid 40s. NAEFS PWAT percentiles
are also running above the 90th percentile, though ground based GPS-
IPW and TPW suggest PWATS are somewhat lower. The relatively moist
conditions have also kept temperatures at bay, which have generally
been running in the mid to upper 90s in the lower deserts. At Sky
Harbor Airport, the high has reached 100 degrees.
Preponderance of hi-res CAMs including the operational and
experimental HRRR continue to indicate that isolated convection will develop
across Gila County this afternoon and this evening. PoPs were increased
to around 10 percent in these areas, though in reality most precipitation
that falls will likely evaporate and not measure at the surface. Models
are in excellent agreement that much drier air will be transported
northeastward this evening and overnight, with the GEFS ensemble
mean indicating PWATS dropping as low as 0.40 inches. Consequently,
showers and thunderstorms will dissipate shortly after sunset.
&&
.PREVIOUS DISCUSSION...
A more significant drop in temperatures will occur on Sunday as
500mb heights drop from around 582DM down to near 576DM due to a slow
moving upper low moving into the Great Basin. As 850mb temperatures
fall roughly 5C from Saturday into Sunday, high temperatures Sunday
will fall back to near normals. Winds will also become gusty Sunday
afternoon ahead of this system with some gusts up to 35 mph in our
typical windier spots of Imperial County and southern Gila County.
By Monday, the upper low will shift southward into portions of the
Desert Southwest with moisture again increasing but still remaining
quite meager over much of the area. Eventually the upper trough is
shown digging southward into the Desert Southwest on Tuesday with the
low center likely tracking southward through western Arizona during
the daytime Tuesday and then slowly shifting eastward into New
Mexico sometime later Wednesday. This track should result in at least
some shower or thunderstorm activity Tuesday afternoon and possibly
into Wednesday. POPs are still mainly limited to higher terrain
locations, but slight chances are still warranted across some south-
central Arizona deserts despite the expected high cloud bases. Highs
will fall even further from the weekend as readings should only top
out near 90 across the deserts for Monday and Tuesday.
Though model spread begins to increase on Wednesday, the overall
consensus shows the upper low shifting east into New Mexico late
Wednesday with increasing heights and warming aloft moving into
western portions of our CWA. This will lead to highs into the middle
to upper 90s across southeast California on Wednesday and likely
areawide on Thursday and Friday. Another even deeper Pacific low
should move into the Pacific Northwest Thursday night into Friday,
but there are doubts on whether it will eventually dig far enough
south to effect our region sometime next weekend.
&&
.AVIATION...
South-Central Arizona including KPHX...KIWA and KSDL...
Southeast California/Southwest Arizona including KIPL and KBLH...
A weak weather disturbance will continue to produce scattered
cumulus and altocumulus with broken-overcast cirrus this afternoon
before thinning out this evening. Over northern and southeastern
Arizona there will be isolated thunderstorms with some additional
weaker showers which will begin dissipating after sunset. Surface
winds will favor south and southwest directions through the evening
(gusts of 15-20 kts Phoenix area; 20-30 kts SE CA and SW AZ). Winds
will be stronger Sunday afternoon but with significantly less
cloudiness.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday...
A low pressure system will be centered over northwest Arizona on
Tuesday and Wednesday leading to a slight chance of thunderstorms
over south-central Arizona. Temperatures will be below normal with
light winds. The low exits Thursday before another system approaches
Friday and Saturday leading to breezy to windy conditions.
Temperatures will start off below normal Tuesday and Wednesday before
climbing back to normal by Friday. Humidities begin declining
Wednesday with Minimum values dipping to about 10% late in the week.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...Hirsch
PREVIOUS DISCUSSION...Kuhlman
AVIATION...AJ
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
500 PM PDT SAT MAY 14 2016
New Aviation Discussion
.SYNOPSIS...
Low pressure aloft is expected to persist much of the next 7
days, supporting night to morning low clouds extending well into
the valleys at times with patchy drizzle and below normal
temperatures. Weaker onshore winds are expected to briefly warm
temperatures above normal during the middle of next week.
&&
.SHORT TERM...(TDY-TUE)
Upper level low currently moving eastward into Oregon and by
Sunday is centered over the Oregon/Idaho border. Around that time
it really becomes a split flow situation to stop its eastward
progression and the low begins to dig southward into Nevada over
the short term forecast. Models generally agree in placing the
center somewhere near Vegas on Tuesday. This trough pattern over
the west coast will result in little day to day changes through
the short term. Expect only minor fluctuations in the depth of the
marine layer and the extent of overnight/morning stratus. Onshore
pressure gradients will be strong enough to slow the pace of
afternoon clearing, with some immediate coastal areas staying in
the stratus through the afternoon. Northwest flow should help keep
the SBA coast clear at night. Had a few reports of drizzle in
Ventura County and overnight drizzle possibilities will continue
each night. Both the GFS and NAM swing a weak area of lift through
the area late tonight and tomorrow morning as the tail end of a
vort lobe around the upper low swings through. This may enhance
the chance of drizzle for tonight mainly over the LA County coast
and valleys. Decided to pull back on the slight chance of showers
in Los Angeles County coast and San Gabriel Valley for Sunday
afternoon/evening, keeping it instead limited to areas higher up
in the foothills.
High temperatures cool some on Sunday but in general will feel
the same. Models warm low levels a bit on Monday to bring a few
degrees warming mainly inland areas and a few degrees again on
Tuesday. Some far inland areas should even be back up above normal
for this time of year.
Winds will be an issue for the Antelope Valley and the Santa
Barbara south coast and adjacent foothills. Winds have been fairly
tame in the Antelope Valley so far but are expected to pick up
later this evening and stay elevated through Sunday night. For
winds in SBA County, gusty northwest winds will develop this
evening and again Sunday evening. Local numerical model indicates
stronger winds for Sunday evening. Another wind advisory will
likely be needed again for the same areas on Sunday night.
Have introduced a slight chance of showers over the eastern San
Gabriels for Tuesday afternoon/evening. With the position of the
closed upper low forecast to be near Vegas Tuesday, there could
be just enough instability and dynamics to produce some showers.
GFS and NAM both showing an area of negative lifted indices along
with some CAPE. Moisture availability will be an issue however.
.LONG TERM...(WED-SAT)
The closed upper low just to our NE is forecast to fill, open up,
and move east on Wednesday. Just enough in the way of height rises
to squeeze a few more degrees of warming Wednesday following
another night of coastal stratus (northwest flow should keep the
SBA south coast clear). Expecting above normal temperatures for
all but the immediate coast which will remain at or just below
normal.
By Thursday the next closed upper low forecast to dive down the
west coast will begin to increase our onshore pressure gradients,
thicken up the marine layer and stratus coverage, and start a
cooling trend that continues into Friday. The cooling will occur
first over inland areas Thursday then spread across the forecast
area Friday. Expect Saturday to be much the same as Friday as far
as marine layer and high temperatures. Some differences in the
east-west position of the low by 12z Saturday with the GFS along
the Oregon coast and the ECMWF further east over OR/ID border. But
this difference won`t impact the forecast for this long term
period.
&&
.AVIATION...
14/0000Z
at 2330Z at KLAX the marine layer was 1800 feet deep. The top of the
inversion top was at 3900 feet with a temperature of 16 degrees
celsius.
Only moderate confidence in TAFs as stratus arrival times will be
tricky and could be off by +/- 2 hours. Good confidence in burn off
times.
KLAX...Moderate confidence in TAF. There is a 30 percent chance that
cigs will remain at 015. There is a 20 percent chance of an east
wind component 8-9 knots from 10Z-15z. There is a 40 percent chance
of no clearing Sunday afternoon.
KBUR...Moderate confidence in TAF. Cigs could arrive anytime between
0500Z and 0900Z. There is a 30 percent chc MVFR cigs will last until
19Z.
&&
.MARINE...
14/200 PM
Northwest winds will continue to create small craft advisory
conditions from Piedras Blancas to San Nicolas island including
the west portion of the Santa Barbara basin through Monday night.
The strongest winds will likely occur in the vicinity of the
Northern Channel islands this afternoon. The Northwest winds will
increase to possible gale force from Piedras Blancas to San
Nicolas island Sunday afternoon and prevail through Monday
morning. Northwest winds are expected to increase Thursday from
Piedras Blancas to San Nicolas island and sca conditions are
likely.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect until 3 AM PDT Sunday For zones
39-52. (See LAXNPWLOX).
Wind Advisory in effect until 9 PM PDT Sunday For zone 59. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 PM PDT Sunday For
zones 645-670-673-676. (See LAXMWWLOX).
Gale Watch in effect from Sunday afternoon through late
Sunday night For zones 645-670-673-676. (See LAXMWWLOX).
Small Craft Advisory in effect until 3 AM PDT Sunday For zone
650. (See LAXMWWLOX).
&&
$$
PUBLIC...Jackson
AVIATION...ASR
MARINE...30
SYNOPSIS...Munroe
weather.gov/losangeles
[top]
Area Forecast Discussion
National Weather Service Phoenix AZ
326 PM MST SAT MAY 14 2016
.UPDATE...
Updated Aviation and Fire Weather sections.
&&
.SYNOPSIS...
High pressure over the region is starting to weaken and shift
eastward. This signals a change to slightly cooler temperatures and
more breezy conditions for the weekend. Another Pacific weather
system is forecast to move into the western states, including parts
of Arizona late Sunday through Tuesday. This will provide even
cooler temperatures along with slight chances of thunderstorms mainly
over northern and central Arizona. Clearing skies with rebounding
afternoon temperatures are forecast for late next week.
&&
.DISCUSSION...
Latest satellite imagery shows several areas of cumulus congestus,
mainly concentrated across the Mogollon Rim, the CO Plateau and
portions of southeastern AZ. Isolated showers and thunderstorms have
developed, but are mainly relegated to the higher terrain near
Tucson and Flagstaff. Meanwhile, moisture values are running well
above average with dewpoints in the mid 40s. NAEFS PWAT percentiles
are also running above the 90th percentile, though ground based GPS-
IPW and TPW suggest PWATS are somewhat lower. The relatively moist
conditions have also kept temperatures at bay, which have generally
been running in the mid to upper 90s in the lower deserts. At Sky
Harbor Airport, the high has reached 100 degrees.
Preponderance of hi-res CAMs including the operational and
experimental HRRR continue to indicate that isolated convection will develop
across Gila County this afternoon and this evening. PoPs were increased
to around 10 percent in these areas, though in reality most precipitation
that falls will likely evaporate and not measure at the surface. Models
are in excellent agreement that much drier air will be transported
northeastward this evening and overnight, with the GEFS ensemble
mean indicating PWATS dropping as low as 0.40 inches. Consequently,
showers and thunderstorms will dissipate shortly after sunset.
&&
.PREVIOUS DISCUSSION...
A more significant drop in temperatures will occur on Sunday as
500mb heights drop from around 582DM down to near 576DM due to a slow
moving upper low moving into the Great Basin. As 850mb temperatures
fall roughly 5C from Saturday into Sunday, high temperatures Sunday
will fall back to near normals. Winds will also become gusty Sunday
afternoon ahead of this system with some gusts up to 35 mph in our
typical windier spots of Imperial County and southern Gila County.
By Monday, the upper low will shift southward into portions of the
Desert Southwest with moisture again increasing but still remaining
quite meager over much of the area. Eventually the upper trough is
shown digging southward into the Desert Southwest on Tuesday with the
low center likely tracking southward through western Arizona during
the daytime Tuesday and then slowly shifting eastward into New
Mexico sometime later Wednesday. This track should result in at least
some shower or thunderstorm activity Tuesday afternoon and possibly
into Wednesday. POPs are still mainly limited to higher terrain
locations, but slight chances are still warranted across some south-
central Arizona deserts despite the expected high cloud bases. Highs
will fall even further from the weekend as readings should only top
out near 90 across the deserts for Monday and Tuesday.
Though model spread begins to increase on Wednesday, the overall
consensus shows the upper low shifting east into New Mexico late
Wednesday with increasing heights and warming aloft moving into
western portions of our CWA. This will lead to highs into the middle
to upper 90s across southeast California on Wednesday and likely
areawide on Thursday and Friday. Another even deeper Pacific low
should move into the Pacific Northwest Thursday night into Friday,
but there are doubts on whether it will eventually dig far enough
south to effect our region sometime next weekend.
&&
.AVIATION...
South-Central Arizona including KPHX...KIWA and KSDL...
Southeast California/Southwest Arizona including KIPL and KBLH...
A weak weather disturbance will continue to produce scattered
cumulus and altocumulus with broken-overcast cirrus this afternoon
before thinning out this evening. Over northern and southeastern
Arizona there will be isolated thunderstorms with some additional
weaker showers which will begin dissipating after sunset. Surface
winds will favor south and southwest directions through the evening
(gusts of 15-20 kts Phoenix area; 20-30 kts SE CA and SW AZ). Winds
will be stronger Sunday afternoon but with significantly less
cloudiness.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday...
A low pressure system will be centered over northwest Arizona on
Tuesday and Wednesday leading to a slight chance of thunderstorms
over south-central Arizona. Temperatures will be below normal with
light winds. The low exits Thursday before another system approaches
Friday and Saturday leading to breezy to windy conditions.
Temperatures will start off below normal Tuesday and Wednesday before
climbing back to normal by Friday. Humidities begin declining
Wednesday with Minimum values dipping to about 10% late in the week.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...Hirsch
PREVIOUS DISCUSSION...Kuhlman
AVIATION...AJ
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
National Weather Service San Diego CA
933 AM PDT FRI MAY 13 2016
.SYNOPSIS...
A deepening marine layer and slow cooling trend will develop
through Sunday as a trough moves by to the north. Night and
morning low clouds will cover the coast and valley areas this
weekend, and occasional drizzle will be possible as well west of
the mountains in the mornings. The trough will also create gusty
westerly winds over the mountains and deserts from late Saturday
through Monday morning. Slightly warmer by the middle of next
week with temperatures near normal as high pressure aloft rebuilds
across the region.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
At 9 AM PDT, water vapor satellite imagery displayed an upper-
level ridge to our east and an upper-level low off the Northern CA
coast with it`s associated trough sagging south. Visible
satellite showed marine layer stratus along the coast and over the
coastal waters. The 13/1200 UTC KNKX sounding showed a 10 deg C
marine layer inversion, which will likely make it difficult for
the stratus to clear today along the beaches. Highs today will be
slightly lower compared to yesterday as upper-level heights lower
with the ridge pushing to the east.
Heights will continue to lower and onshore flow will strengthen
through Sunday as the upper-level trough approaches the region.
Increasing pressure gradients will strengthen westerly winds this
weekend into early next week, creating gusts of 45-55 MPH and
reduced visibility from blowing dust at times Sunday and Monday
across portions of the mountains and deserts. The marine layer
will become quite deep this weekend, pushing night/morning low
clouds towards the coastal mountain slopes. Patchy drizzle is
expected west of the mountains Sunday and Monday mornings. Inland
high temperatures will lower to around 5 deg F below normal Sunday
and Monday.
The 13/0600 UTC GFS and 13/0000 UTC ECMWF are now hinting at the
aforementioned upper-level low digging south from NV to Western
AZ Tuesday, which could generate weak offshore flow inland. Weak
ridging will build over the region Wednesday and Thursday,
creating a more shallow marine layer and a slight warming trend.
Stronger onshore flow and a cooling trend may develop by the end
of next week heights aloft lower due to an upper-level low
approaching Northern CA.
&&
.AVIATION...
131500Z...Coast/Valleys...Stratus 15-25 SM inland, with bases 1000-
1200 FT MSL, tops around 1700-1900 FT MSL, areas of VIS 3-5 SM BR,
and local VIS AOB 1 SM VCNTY KRNM and KAJO will likely clear to
within 3 SM of the coast through 1800 UTC. Marine layer inversion
strength of around 9-10 DEG C. 1800-14/0000 UTC, mostly SKC except
within 3 SM of the coast where BKN-SCT clouds in the 1200-1500 FT
MSL may linger. 14/0000-1500 UTC, stratus re-developing and
gradually pushing inland 25-50 SM, with bases rising to 1300-1700 FT
MSL and bases rising to 2200-2500 FT MSL. Areas of VIS 3-5 SM BR
likely in the inland valleys. Forecast confidence is moderate.
Mountains/Deserts...Unrestricted VIS through Saturday morning with
SKC then increasing clouds AOA 20000 FT MSL after 14/0000 UTC.
&&
.MARINE...
800 AM...No hazardous marine weather is expected through Tuesday.
&&
.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
&&
.SGX Watches/Warnings/Advisories...
CA...None.
PZ...None.
&&
$$
PUBLIC...JJT
AVIATION/MARINE...Harrison
Area Forecast Discussion
National Weather Service San Francisco Bay Area
923 AM PDT FRI MAY 13 2016
.Synopsis... A low pressure system will begin to influence the
region today... leading to cooler temperatures and a slight
chance of rain over the North Bay on Saturday. Drier weather
conditions and a slight warming trend is then expected for next
week as high pressure builds over the region.
&&
.Discussion...as of 09:15 AM PDT Friday... Today is Friday the
13th and another May gray day is upon us. The persistent marine
layer that has inundated inland coastal regions over the last few
mornings is evident again this morning on satellite imagery,
especially around the Monterey Bay region. That said, satellite
imagery is signaling that the marine layer is not nearly as robust
as it has been over the last few days.
These signals include a) higher cloud bases, which are generally
500-900 feet higher than the last two mornings and are approaching
the top of the marine layer itself. b) The Fort Ord Profiler tops
the marine deck just above 2000 feet and bases are already pushing
1700-1800 feet in the Bay Area, which indicates a much shallower
layer there than previous mornings. c) The GOES-R proving grounds
cloud thickness product shows rather shallow cloud depths of
100-600 feet throughout most of the inland SF Bay Area as opposed
to 1000+ feet. And d) satellite imagery shows a few holes in the
previously uniform offshore deck.
This change can largely be attributed to changes in the
nearshore air mass and flow ahead of an approaching upper level
trough. Trough interactions with the marine stratus deck are
usually fairly tricky, however, expect to see an earlier stratus
retreat in the San Francisco Bay Area versus the Monterey Bay
region where the stratus deck could linger into the afternoon.
This feature will begin to influence the regional weather today
and increasingly so into the weekend as it treks eastward across
the Pacific Northwest. Temperatures will struggle to warm today
and are expected to end the day a few degrees cooler than
yesterday... and a few to several degrees cooler than the daily
normal.
Coastal drizzle has been reported and can be expected along the
coast through morning, especially around the Monterey Bay region
where the stratus deck is thicker. A slight chance of rain showers
also exists in the north bay as the upper low shifts onshore to
the north late tonight into early tomorrow.
High pressure builds back into the region early next week...
leading to a general warming trend into midweek where temperatures
are expected to run a few to several degrees above normal.
.Previous discussion...AS OF 03:59 AM PDT Friday...A persistent
marine layer around 2000 feet in depth continues to impact the
region with low clouds spreading well inland this morning. With
this, temperatures are holding steady in the 50s for most
locations under the cloud cover. As with the past few days, clouds
will slowly burn-off through late morning over inland locations.
Meanwhile, many coastal areas will remain under cloud cover
through much of the day. Temperatures inland are forecast to be
slightly cooler compared to yesterday given an increased onshore
flow and as the mid/upper level ridge shifts inland.
A mid/upper level system remains on track to push inland over the
Pacific Northwest on Saturday. The latest forecast models push this
system inland to our north, yet show light precipitation moving over
the northern coastal waters and into the North Bay region early
Saturday morning. Given better consistency with the forecast models,
have increased coverage of a slight chance of showers from the San
Francisco Peninsula Coast northward into the North Bay. Further
south, expecting the marine layer to deepen ahead of the approaching
trough tonight into Saturday morning which should result in
continued chances of coastal drizzle. Otherwise, most locations
south of the Golden Gate will remain dry as this system passes
inland. Temperatures will generally remain below seasonal averages
inland through the weekend due to the proximity of the mid/upper
level trough.
Mid/upper level ridging will then build over the eastern Pacific
early next week and result in a gradual warming trend and continued
dry weather conditions. In addition, northwesterly winds along the
coast will increase and likely help with mixing of the marine layer.
As a result, cloud cover will likely be less extensive each morning,
at least less of an inland intrusion. Temperatures will warm back
above average by Tuesday and persist into Wednesday given a warmer,
drier air mass aloft. The warm-up will be short lived overall as the
medium range models project another mid/upper level ridge impacting
the Pacific Northwest late next week.
&&
.Aviation...As of 4:46 AM PDT Thursday...Widespread stratus is
moving in over the area on onshore winds. Clearing expected
between 17z-19z across most terminals with the exception of the
Monterey Bay terminals which may not clear until 20z-21z.
Vicinity of KSFO...MVFR cigs then clearing anticipated around 18z
today. Mainly light onshore winds except up to 15-20 kt 21z-04z.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...IFR cigs persist through this morning. Cigs
anticipated to scatter out around 20z-21z today. Mainly light winds.
IFR cigs return this evening.
&&
.Marine...as of 08:09 AM PDT Friday...A weak gradient over the
coastal waters will maintain light winds and seas through
saturday. gusty winds are possible over the san francisco bay
waters north of the bay bridge this afternoon and evening. winds
increase late in the weekend into early next week as a low
pressure system moves across the area. northwesterly swell will be
mixed with a small long period southerly swell.
&&
.MTR Watches/Warnings/Advisories...
.Tday...SCA...SF BAY FROM 1 PM
&&
$$
Public Forecast: DRP
Aviation: Canepa
Marine: Canepa
Visit us at www.weather.gov/sanfrancisco
Follow us on Facebook and twitter at:
www.Facebook.com/nwsbayarea
www.twitter.com/nwsbayarea
Area Forecast Discussion
National Weather Service San Francisco Bay Area
923 AM PDT FRI MAY 13 2016
.Synopsis... A low pressure system will begin to influence the
region today... leading to cooler temperatures and a slight
chance of rain over the North Bay on Saturday. Drier weather
conditions and a slight warming trend is then expected for next
week as high pressure builds over the region.
&&
.Discussion...as of 09:15 AM PDT Friday... Today is Friday the
13th and another May gray day is upon us. The persistent marine
layer that has inundated inland coastal regions over the last few
mornings is evident again this morning on satellite imagery,
especially around the Monterey Bay region. That said, satellite
imagery is signaling that the marine layer is not nearly as robust
as it has been over the last few days.
These signals include a) higher cloud bases, which are generally
500-900 feet higher than the last two mornings and are approaching
the top of the marine layer itself. b) The Fort Ord Profiler tops
the marine deck just above 2000 feet and bases are already pushing
1700-1800 feet in the Bay Area, which indicates a much shallower
layer there than previous mornings. c) The GOES-R proving grounds
cloud thickness product shows rather shallow cloud depths of
100-600 feet throughout most of the inland SF Bay Area as opposed
to 1000+ feet. And d) satellite imagery shows a few holes in the
previously uniform offshore deck.
This change can largely be attributed to changes in the
nearshore air mass and flow ahead of an approaching upper level
trough. Trough interactions with the marine stratus deck are
usually fairly tricky, however, expect to see an earlier stratus
retreat in the San Francisco Bay Area versus the Monterey Bay
region where the stratus deck could linger into the afternoon.
This feature will begin to influence the regional weather today
and increasingly so into the weekend as it treks eastward across
the Pacific Northwest. Temperatures will struggle to warm today
and are expected to end the day a few degrees cooler than
yesterday... and a few to several degrees cooler than the daily
normal.
Coastal drizzle has been reported and can be expected along the
coast through morning, especially around the Monterey Bay region
where the stratus deck is thicker. A slight chance of rain showers
also exists in the north bay as the upper low shifts onshore to
the north late tonight into early tomorrow.
High pressure builds back into the region early next week...
leading to a general warming trend into midweek where temperatures
are expected to run a few to several degrees above normal.
.Previous discussion...AS OF 03:59 AM PDT Friday...A persistent
marine layer around 2000 feet in depth continues to impact the
region with low clouds spreading well inland this morning. With
this, temperatures are holding steady in the 50s for most
locations under the cloud cover. As with the past few days, clouds
will slowly burn-off through late morning over inland locations.
Meanwhile, many coastal areas will remain under cloud cover
through much of the day. Temperatures inland are forecast to be
slightly cooler compared to yesterday given an increased onshore
flow and as the mid/upper level ridge shifts inland.
A mid/upper level system remains on track to push inland over the
Pacific Northwest on Saturday. The latest forecast models push this
system inland to our north, yet show light precipitation moving over
the northern coastal waters and into the North Bay region early
Saturday morning. Given better consistency with the forecast models,
have increased coverage of a slight chance of showers from the San
Francisco Peninsula Coast northward into the North Bay. Further
south, expecting the marine layer to deepen ahead of the approaching
trough tonight into Saturday morning which should result in
continued chances of coastal drizzle. Otherwise, most locations
south of the Golden Gate will remain dry as this system passes
inland. Temperatures will generally remain below seasonal averages
inland through the weekend due to the proximity of the mid/upper
level trough.
Mid/upper level ridging will then build over the eastern Pacific
early next week and result in a gradual warming trend and continued
dry weather conditions. In addition, northwesterly winds along the
coast will increase and likely help with mixing of the marine layer.
As a result, cloud cover will likely be less extensive each morning,
at least less of an inland intrusion. Temperatures will warm back
above average by Tuesday and persist into Wednesday given a warmer,
drier air mass aloft. The warm-up will be short lived overall as the
medium range models project another mid/upper level ridge impacting
the Pacific Northwest late next week.
&&
.Aviation...As of 4:46 AM PDT Thursday...Widespread stratus is
moving in over the area on onshore winds. Clearing expected
between 17z-19z across most terminals with the exception of the
Monterey Bay terminals which may not clear until 20z-21z.
Vicinity of KSFO...MVFR cigs then clearing anticipated around 18z
today. Mainly light onshore winds except up to 15-20 kt 21z-04z.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...IFR cigs persist through this morning. Cigs
anticipated to scatter out around 20z-21z today. Mainly light winds.
IFR cigs return this evening.
&&
.Marine...as of 08:09 AM PDT Friday...A weak gradient over the
coastal waters will maintain light winds and seas through
saturday. gusty winds are possible over the san francisco bay
waters north of the bay bridge this afternoon and evening. winds
increase late in the weekend into early next week as a low
pressure system moves across the area. northwesterly swell will be
mixed with a small long period southerly swell.
&&
.MTR Watches/Warnings/Advisories...
.Tday...SCA...SF BAY FROM 1 PM
&&
$$
Public Forecast: DRP
Aviation: Canepa
Marine: Canepa
Visit us at www.weather.gov/sanfrancisco
Follow us on Facebook and twitter at:
www.Facebook.com/nwsbayarea
www.twitter.com/nwsbayarea
Area Forecast Discussion
National Weather Service Phoenix AZ
908 AM MST FRI MAY 13 2016
.SYNOPSIS...
A high pressure system over the region will result in above normal
temperatures through Saturday. However, another Pacific weather
system is forecast to move into the western states, including parts
of Arizona late Sunday through Tuesday, providing cooler
temperatures and a slight chance of thunderstorms mainly over
northern and central Arizona. Clearing skies with rebounding
afternoon temperatures are forecast next Wednesday and Thursday.
&&
.DISCUSSION...
Latest satellite images show sunny skies across the Desert
Southwest. However, some mid and high clouds are evident across
Sonora and will continue to drift northeastward and into eastern AZ
this afternoon ahead of a weak upper level trough off the Baja
Peninsula. Latest hi-res models including the HRRR continue to show
very little potential for convection this afternoon associated with
this system.
The bigger story today will be the above average temperatures.
Forecast high of 104 degrees in Phoenix still looks on track and this
would be the warmest temperature of the year so far. Latest 12z TWC
sounding registered an 850 mb temperature around the 90th percentile,
which is also in line with the NAEFS percentiles. What this means is
that we`re not looking for record temperatures. We`ll likely fall
several degrees short at both Phoenix and Yuma.
&&
.PREVIOUS DISCUSSION...
Strong upper level ridge remains parked over the Desert Southwest
with heights aloft near the upper end of climatological norms. These
heights will continue to bring very warm temperatures to the region
through Saturday with many lower desert spots topping 100 degrees.
Forecast high temperatures will still fall short of records by
several degrees.
Looking well to the south across the Baja Peninsula weak cyclonic
flow has allowed for some thunderstorm activity over the past few
hours. Models indicate a surge of moisture between 12-15K feet will
move out of Mexico into southern Arizona later this morning or this
afternoon, but overall subsidence aloft and very dry air below 10K
feet should limit any convective activity. Hi-res models do show some
shower or thunderstorm activity potential for this afternoon, but
staying south and east of our CWA. Have increased POPs south of
Phoenix, but still less than a 10 percent chance. The most likely
scenario would be a few isolated high based showers and maybe a
thunderstorm across TWC`s area.
As the upper level ridge shifts eastward by tonight the cyclonic
flow will move into Arizona on Saturday while also becoming less
pronounced. A similar scenario for the daytime hours Saturday should
result in a few isolated showers or thunderstorms over TWC`s area
with less than 10 percent chances across our northern Pinal and
southern Gila county areas. As heights aloft finally start to
decrease, Saturday`s highs will dip slightly, but a good portion of
the lower deserts should again top 100 degrees.
Overall model agreement remains high through the rest of the weekend
and even into early next week as a large scale trough slowly shifts
across the Western United States. The main PV anomaly and upper level
low center is forecast to slowly drift southward into the Great
Basin on Sunday and Monday allowing further height falls across the
Desert Southwest. This will turn our flow mainly out of the west
allowing for some drying initially and ending any chance of isolated
convective activity. Cooler air will also filter into the region as
highs fall back closer to normals or even slightly below. Winds will
also increase on Sunday as a surface low develops across the Central
Rockies. Wind gusts up to 35 mph will be possible across portions of
the area Sunday afternoon which may result in some patchy areas of
blowing dust.
Eventually the main upper level low should shift southward into the
Desert Southwest sometime Tuesday, though model spread increases by
this point. Overall moisture will be fairly limited, but at this
point is seems the upper low should dig far enough south and west of
our area to bring at least some slight chances for showers or
thunderstorms across southern Arizona on Tuesday, possibly lingering
into early Wednesday. Near normal temperatures should persist
through the end of next week with no drastic changes in the overall
weather pattern.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...SOUTHEAST
CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
High pressure remains the dominant weather feature over the
region...promoting periods of mostly clear skies and typical wind
patterns with mainly light speeds. Weak upper disturbance located in
the central Gulf of California continues to track northward this
AM...introducing the potential for some increasing moisture levels
through the mid-atmo layers. Could see some FEW to SCT mid-level
clouds by the afternoon. Elevated south to southeasterly flow will
also result for the western terminals of KIPL and KBLH throughout the
day.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
Sunday through Thursday...
Low pressure approaching from the west will bring cooler
temperatures to the district from Sunday onward into Tuesday, with
highs in the low-mid 90s on Sunday falling into the upper 80-low 90
range on Monday and Tuesday. Gusty westerly winds in the 15-25 mph
range on Sunday and Monday will elevate fire danger levels across the
region, although higher humidities, in the 15-20 percent range, will
keep fire danger levels from reaching critical thresholds for most
locations. Localized pockets of critical conditions may be realized
across portions of Gila County Sunday afternoon. High pressure
building back into the region from the west will then bring warmer
temperatures to the region on Wednesday and Thursday, with lower
desert highs approaching 100 by Thursday. Lighter winds are also
forecast, tending towards typical diurnal and drainage following
trends.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR Watches/Warnings/Advisories...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
Discussion...Hirsch
Previous Discussion...Kuhlman
Aviation...Nolte
Fire Weather...Nolte/Percha
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1228 PM CDT FRI MAY 13 2016
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 325 AM CDT FRI MAY 13 2016
In the short term, the forecast problem of the day is the extent and
timing of thunderstorm chances this afternoon across northeast
Kansas. Northwest flow aloft prevails across the central and western
CONUS this morning. A shortwave is forecast to amplify today as it
dives southeast into the central US. Latest water vapor imagery
confirms this with an impressive vort max just north of the Canadian
border north of North Dakota. A surface low over eastern Wyoming at
06 UTC is forecast to move quickly southeast in association with the
applying upper trough reaching eastern Iowa by 21 UTC today with a
trailing cold front across northern Missouri and eastern Kansas. The
front should enter our forecast area around 18 UTC and exit around
00 UTC/Sat. The models are in good agreement concerning the timing
of the front. All of the convection resolving high-resolution
models develop thunderstorms along the front over eastern Kansas
between 18-21 UTC and exiting the area shortly after 00 UTC. The
main concern this morning is low-level moisture. Moisture from the
Gulf of Mexico is currently blocked by a surface ridge over the
southern plains. The models all bring a narrow ribbon of moisture
rapidly northeast into eastern Kansas just ahead of the front. This
will likely occur to some extent. Thinking is that there should be
decent coverage of initially high-based, but surface based storms
which should develop and increasingly favorable deep shear
environment. It will be interesting to see if there will be any low-
level backing of the winds which would result in better low-level
shear. At this point, the primary risk should be hail and wind.
Given the deep shear, the storms have a good chance being organized
with discrete storms early before developing cold pools into a
linear system.
Strong cold advection tonight which will result in sharply lower
temperatures. Will probably see mid/high clouds late due to
channeled vorticity aloft, but will not mention precipitation at
this time. The airmass looks dry below 700 MB.
.LONG TERM...(Saturday through Thursday)
Issued at 325 AM CDT FRI MAY 13 2016
Northwest flow aloft will be in place through the weekend, with
multiple embedded shortwaves bringing chances for precipitation.
Saturday morning may be met with only light showers across the area,
given that air nearest to the surface is relatively dry. Surface
flow from the north will aid in keeping temperatures much cooler
than recently seen, with highs in the low 60s. Surface high
pressure moves in from the northwest during the day Saturday, moving
over NE Kansas overnight. Clouds streaming in from the northwest
will move over central and east central Kansas by early morning.
With time to cool before clouds move in, lows are still expected to
be in the low 40s, even lower in far northeast Kansas where cloud
cover will not be as prominent. Precipitation chances start again
on Sunday as a series of shortwaves ahead of an upper level low
located over the northwest CONUS move near Kansas. Chances increase
from Sunday night though Tuesday as ascent ahead of the low and
multiple shortwaves bring chances for primarily rain showers, as
instability is very limited due to the cooler temperatures in place.
This system is forecast to move east and out of the area Tuesday
night, allowing for a brief period of dry conditions Wednesday into
Wednesday night. A southern stream trough will bring the next
chances for rain and thunderstorms to the area Thursday and Friday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday Afternoon)
Issued at 1221 PM CDT FRI MAY 13 2016
A line of scattered storms will move through the taf sites. There
is a chance of brief MVFR conditions within the individual storms.
Confidence of a particular storm hitting the site is moderate
therefore have added the tempo group. Large hail and damaging
winds will be possible with these storms. VFR conditions and a
wind shift is expected after the front moves through.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Johnson
LONG TERM...Heller
AVIATION...Sanders
Area Forecast Discussion
National Weather Service Goodland KS
1127 AM MDT FRI MAY 13 2016
.UPDATE...
Issued at 946 AM MDT Fri May 13 2016
Cold front has made it as far south as KGLD and KCBK and will
continue to move south rapidly today. Winds around 30 mph will
accompany frontal passage and will be slow to decrease through the
day. High temps likely already reached as temps begin to fall.
&&
.SHORT TERM...(Today through Sunday night)
Issued at 330 AM MDT Fri May 13 2016
Today-tonight...cold front quickly moves south across the forecast
area before noon bringing north winds gusting to around 30 mph and
slowly decreasing temperatures from north to south through the day.
By late in the day winds will subside a bit closer to 10 to 15 mph
from the north-northeast. Not much in the way of cloudiness til late
afternoon unless cirrus currently northwest of us moves down. High
temperatures will range from the mid 60s to near 70 along/north of
the KS/NE border to the mid/upper 70s in the Tribune and Leoti
areas. For tonight a 1030mb sfc high moves down from the north
allowing overnight low temperatures to drop into the mid 30s to
around 40. Will have to watch for possible impacts of quickly
increasing cloudiness on the overnight lows as this will prevent
less than ideal radiational cooling with the light sfc winds and
sfc high over the area. A few rain showers are possible from near
Yuma to Oberlin and Norton northward after midnight where some mid
level frontogenesis exists within a layer of moisture in the
700-500 layer.
Saturday-Saturday night...Plenty of moisture below 700mb suggesting
a mostly cloudy to cloudy sky through the period. The mid levels of
the atmosphere dry out thus am not forecasting any precipitation
during the day. It will be rather cool with afternoon temperatures
in the mid 50s to near 60. For Saturday night the mid levels of the
atmosphere moisten up after midnight while the lower levels remain
moist through the night. As a result have precipitation chances
slowly increasing after midnight with some light rain showers
possible. Low temperatures in the upper 30s to low 40s.
Sunday-Sunday night...Will continue with slight chance/chance pops
during the morning and early afternoon before some drier air aloft
moves in from the west bringing an end to the rain showers by days
end. The GFS model hangs on to some slight chance pops across the
far east while the NAM pushes the better moisture out of the area
late in the day. Surface pressure gradient increases between
departing sfc high and low pressure along the front range. This will
create breezy to windy southeast winds across much of the area by
late morning through late afternoon. Afternoon temperatures will
remain well below normal with low to mid 50s. For Sunday night
another weather disturbance moves into the area from the west
creating another chance for light rain showers. Low temperatures in
the low to mid 40s.
.LONG TERM...(Monday through Thursday)
Issued at 224 AM MDT Fri May 13 2016
The area of low pressure situated over the northern rockies will
slide southward on Monday with both the ECMWF and GFS in good
agreement on this solution. PoPs will be in the 50 to 70 percent
range on Monday and into Monday night/Tuesday morning. Instability
is marginal at this point with the exception of the south and
southwest portions of the region. A few strong to perhaps severe
storms are possible in the southern and southwestern portions of
the CWA as CAPE will be in the 1200 to 2000 J/KG range with bulk
shear in the 30 to 40 knot range. I went with 50 to 60 percent
PoPs early Tuesday morning with diminishing precip chances
thereafter as the H5 low and associated trough slide further
south, taking the better rain chances with it. For Tuesday night,
slight PoPs are in the forecast early however things should dry
out by Wednesday morning and remain dry through the early
afternoon. A weak north/south oriented boundary in eastern
Colorado will provide a focus for potential thunderstorm
development during the mid to late afternoon hours on Wednesday.
Precipitation chances diminish as we head through the day on
Thursday with slight chances through around midday mainly in the
eastern half of the CWA.
Temperatures will remain below normal Monday through Wednesday with
daytime highs only reaching into the 50s and 60s. Warmer and more
seasonal highs return for Thursday with highs in the 70s. Lows will
be in the lower to middle 40s each night.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1124 AM MDT Fri May 13 2016
VFR conditions will prevail for this TAF cycle as strong cold
front has already moved through both terminals bringing northerly
winds between 20 and 30 kts with a gradual decrease expected
through the late afternoon hours. Could potentially see a brief
period of MVFR cigs at KMCK...but trends in satellite tend to
favor cloud deck breaking apart before reaching location.
Othwerise...may see a shower or two develop at MCK after 7z...but
expect minimal impact on aviation at this time.
&&
.GLD Watches/Warnings/Advisories...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...99
LONG TERM...TL
AVIATION...JRM
Area Forecast Discussion
National Weather Service Wichita KS
1114 AM CDT FRI MAY 13 2016
.UPDATE...
Issued at 1114 AM CDT Fri May 13 2016
Latest HRRR/RAP/NAM develop convection along the Canadian cold
front early this afternoon from northeast into central Kansas.
While the NAM is seemingly way too bullish on surface dew points
and the resultant instability, a more reasonable depiction of
eventual mid 50s Td`s should yield SBCAPE values near 1500 J/KG
near peak heating along the front where deep layer shear at or
above 40 kts will be present. Besides rather steep lapse rates,
RAP point soundings also show large DCAPE values well over 1000
J/KG. This supports damaging down-burst winds and large hail
which is reflected in the current hazardous weather outlook.
It is possible that storm coverage and effective outflow could
push the effective front a bit faster southeast across southern
Kansas early this evening taking the bulk of the activity out of
the forecast area by 03z. Due to rather high LCL heights the
tornado risk appears relatively low, however the initial stronger
updrafts could tie into some local helicity as the storms
develop/zipper southwest along boundary this afternoon, so a few
funnels may be possible.
KED
&&
.SHORT TERM...(Today through tonight)
Issued at 329 AM CDT Fri May 13 2016
Forecast highlights the next 7-10 days focus around severe storm
chances this afternoon-evening, much cooler this weekend into
early/mid next week, and increasing precipitation chances late
weekend into early next week.
A strong cold front, currently analyzed across Wyoming and South
Dakota, will surge south across the Heartland today, supporting
increasing thunderstorm chances after roughly 3pm this afternoon.
Initiation will likely occur first over northeast Kansas closer to
upper forcing, with isolated to widely scattered thunderstorms
zippering down the cold front to the southwest, generally along
and north of the Highway 50 corridor. Despite only modest moisture
return (boundary layer dewpoints low-mid 50s), steep mid-level
lapse rates should support MLCAPE values up to 1500 j/kg. This in
concert with 40-50 kts of deep layer shear should support a
handful of strong-severe storms. Main threats will likely be large
hail and damaging winds. Despite some hints at modest low-level
shear per cyclonically looping hodographs, tornado threat should
be minimal due to relatively high cloud bases. Activity will then
move into southern and southeast Kansas during the evening,
likely diminishing after dark due to limited moisture/instability,
lack of low-level jet and best forcing remaining well northeast of
the region.
ADK
.LONG TERM...(Saturday through Thursday)
Issued at 329 AM CDT Fri May 13 2016
Of particular note will be the much cooler air in wake of this
front. After high temperatures in the 70s-80s today, daytime
temperatures in the 50s-60s are expected Saturday through Tuesday,
about 15-20 degrees cooler than normal. Consequently, could be
flirting with record cool high temperatures. Furthermore, expect
shower/thunderstorm chances to increase from the southwest
especially by sunday and Sunday night, likely becoming
widespread/numerous for Monday into early Tuesday, as an upper
shortwave approaches from the southwest. All-in-all, concentrated
severe weather probabilities should remain highest generally south
of the KS/OK border, although increasing elevated moisture and
instability may support strong storms over southern Kansas late
Sunday night through Monday evening. After a break Tuesday night
and Wednesday, medium range model consensus supports increasing
precipitation chances for late week, along with a return to near
normal temperatures, as a western conus trough approaches.
ADK
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 459 AM CDT Fri May 13 2016
Main aviation hazards: low-level wind shear early this morning,
then potential for a few strong storms this afternoon.
A 40-45 knot south-southwesterly low-level jet may result in low-
level wind shear in South-Central Kansas and the Flint Hills early
this morning, with very light winds at the surface until about
14z.
A strong cold front will push southeastward through
Central/Southeastern Kansas this afternoon into early this
evening. Gusty southwesterly winds ahead of the front, will shift
to gusty northwesterly behind the frontal passage. Feel scattered
storms will develop initially over northeastern Kansas where cap
will be breached first, with development proceeding southwestward
into South-Central/Southeast Kansas toward mid afternoon into
early evening, before storms clear out of southeast Kansas. Hail
and strong wind gusts will accompany the strongest storm cores.
North-northeasterly winds will diminish later this evening.
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 82 46 62 46 / 30 30 10 20
Hutchinson 82 44 62 43 / 30 20 10 20
Newton 81 43 59 44 / 30 20 10 10
ElDorado 81 45 61 45 / 40 40 10 10
Winfield-KWLD 83 47 62 47 / 30 40 10 20
Russell 79 42 62 43 / 10 10 10 20
Great Bend 81 42 62 43 / 20 10 10 20
Salina 81 43 63 43 / 20 10 20 10
McPherson 81 42 62 42 / 30 10 10 20
Coffeyville 81 48 62 46 / 40 60 10 10
Chanute 81 46 62 44 / 50 60 10 10
Iola 80 46 62 43 / 50 60 20 10
Parsons-KPPF 81 47 62 45 / 50 60 10 10
&&
.ICT Watches/Warnings/Advisories...None.
&&
$$
UPDATE...KED
SHORT TERM...ADK
LONG TERM...ADK
AVIATION...JMC
Area Forecast Discussion
National Weather Service Goodland KS
948 AM MDT FRI MAY 13 2016
.UPDATE...
Issued at 946 AM MDT Fri May 13 2016
Cold front has made it as far south as KGLD and KCBK and will
continue to move south rapidly today. Winds around 30 mph will
accompany frontal passage and will be slow to decrease through the
day. High temps likely already reached as temps begin to fall.
&&
.SHORT TERM...(Today through Sunday night)
Issued at 330 AM MDT Fri May 13 2016
Today-tonight...cold front quickly moves south across the forecast
area before noon bringing north winds gusting to around 30 mph and
slowly decreasing temperatures from north to south through the day.
By late in the day winds will subside a bit closer to 10 to 15 mph
from the north-northeast. Not much in the way of cloudiness til late
afternoon unless cirrus currently northwest of us moves down. High
temperatures will range from the mid 60s to near 70 along/north of
the KS/NE border to the mid/upper 70s in the Tribune and Leoti
areas. For tonight a 1030mb sfc high moves down from the north
allowing overnight low temperatures to drop into the mid 30s to
around 40. Will have to watch for possible impacts of quickly
increasing cloudiness on the overnight lows as this will prevent
less than ideal radiational cooling with the light sfc winds and
sfc high over the area. A few rain showers are possible from near
Yuma to Oberlin and Norton northward after midnight where some mid
level frontogenesis exists within a layer of moisture in the
700-500 layer.
Saturday-Saturday night...Plenty of moisture below 700mb suggesting
a mostly cloudy to cloudy sky through the period. The mid levels of
the atmosphere dry out thus am not forecasting any precipitation
during the day. It will be rather cool with afternoon temperatures
in the mid 50s to near 60. For Saturday night the mid levels of the
atmosphere moisten up after midnight while the lower levels remain
moist through the night. As a result have precipitation chances
slowly increasing after midnight with some light rain showers
possible. Low temperatures in the upper 30s to low 40s.
Sunday-Sunday night...Will continue with slight chance/chance pops
during the morning and early afternoon before some drier air aloft
moves in from the west bringing an end to the rain showers by days
end. The GFS model hangs on to some slight chance pops across the
far east while the NAM pushes the better moisture out of the area
late in the day. Surface pressure gradient increases between
departing sfc high and low pressure along the front range. This will
create breezy to windy southeast winds across much of the area by
late morning through late afternoon. Afternoon temperatures will
remain well below normal with low to mid 50s. For Sunday night
another weather disturbance moves into the area from the west
creating another chance for light rain showers. Low temperatures in
the low to mid 40s.
.LONG TERM...(Monday through Thursday)
Issued at 224 AM MDT Fri May 13 2016
The area of low pressure situated over the northern rockies will
slide southward on Monday with both the ECMWF and GFS in good
agreement on this solution. PoPs will be in the 50 to 70 percent
range on Monday and into Monday night/Tuesday morning. Instability
is marginal at this point with the exception of the south and
southwest portions of the region. A few strong to perhaps severe
storms are possible in the southern and southwestern portions of
the CWA as CAPE will be in the 1200 to 2000 J/KG range with bulk
shear in the 30 to 40 knot range. I went with 50 to 60 percent
PoPs early Tuesday morning with diminishing precip chances
thereafter as the H5 low and associated trough slide further
south, taking the better rain chances with it. For Tuesday night,
slight PoPs are in the forecast early however things should dry
out by Wednesday morning and remain dry through the early
afternoon. A weak north/south oriented boundary in eastern
Colorado will provide a focus for potential thunderstorm
development during the mid to late afternoon hours on Wednesday.
Precipitation chances diminish as we head through the day on
Thursday with slight chances through around midday mainly in the
eastern half of the CWA.
Temperatures will remain below normal Monday through Wednesday with
daytime highs only reaching into the 50s and 60s. Warmer and more
seasonal highs return for Thursday with highs in the 70s. Lows will
be in the lower to middle 40s each night.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 330 AM MDT Fri May 13 2016
For KGLD and KMCK...vfr conditions expected through the period.
Both terminals will have a cold front move through this morning
creating northerly winds gusting to 30kts or so. By mid to late
afternoon winds slowly veer to the northeast while also slowly
decreasing. For tonight winds remain light from the northeast
(KMCK) and east (KGLD) at speeds under 10kts. Both terminals may
see some cirrus during the day with some increase in low and mid
level cloudiness very late in the day through tonight. KMCK may
experience some light rain showers from 6z through the rest of the
taf period.
&&
.GLD Watches/Warnings/Advisories...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...99
LONG TERM...TL
AVIATION...99
Area Forecast Discussion
National Weather Service Dodge City KS
620 AM CDT FRI MAY 13 2016
...Updated Aviation discussion...
.SHORT TERM...(Today and tonight)
Issued at 1230 AM CDT Fri May 13 2016
Precip chances return late today as short range models indicate an
upper level shortwave trough cycling southeast across the Upper
Midwest, sending an attendant cold front southward across the
Central Plains. Meanwhile, a recently re-established low level
southerly flow will begin to slowly draw moisture up into central
and portions of southwest Kansas with surface dewpoints climbing
well into the 50s(F) ahead of the approaching cold front. Although
the flow aloft will remain less than favorable with a strong jet
core staying off to our northeast across the Upper Midwest, it
will be strong enough to help support shower and thunderstorm
development late this afternoon as capping weakens while the front
pushes into more readily available moisture. Ample instability
with SBCAPE in excess of 2,000 J/KG and favorable deep layer shear
will increase the potential for strong to marginally severe
thunderstorms into early to mid evening across south central
Kansas.
As for temperatures, surface high pressure drifting southeast into
the Ark-La-Tex Region while a surface low approaching from the
northwest deepens will create a fairly strong southwest flow across
western Kansas later this morning into early afternoon. This will
enhance warm air advection raising H85 temperatures into the mid
and upper teens(C) across central Kansas to a little above 20C in
extreme southwest Kansas. With fairly steep lapse rates developing
by this afternoon ahead of the front, look for highs well up into
the 80s(F) across central and much of southwest Kansas. Colder air
will spill southward into western Kansas late tonight dropping
temperatures into the 40s(F) for lows by daybreak Saturday
morning.
.LONG TERM...(Saturday through Thursday)
Issued at 100 AM CDT Fri May 13 2016
Precip chances dwindle Saturday as much drier air filters southwest
into western Kansas behind a cold front plunging further south into
north Texas. Precip chances return Sunday as a series of H5 vort
maxima kick out of the Colorado Rockies into the Western High
Plains within a westerly flow aloft. Surface high pressure pushing
east across the Central Plains will return a southeasterly upslope
flow to western Kansas, and in turn, increase moisture somewhat
across southwest and west central Kansas. As the H5 vort maxima
move into the high plains, showers and thunderstorms are expected
to develop in the vicinity of a stationary frontal boundary/trough
in eastern Colorado, then spread eastward into western Kansas
during the day Sunday and possibly into Monday.
Much cooler temperatures are on the way Saturday as colder air
associated with a surface high moving across the Northern Plains
surges southward into western Kansas. The GFS and ECMWF show H85
temperatures dropping as low as the mid single digits(C) across
central Kansas to near 10C in extreme southwest Kansas. Expect highs
in the upper 50s(F) to the lower 60s(F) Saturday afternoon. Similar
highs can be expected Sunday with the cooler air mass slow to erode
as surface high pressure drops southeast across the Central Plains.
Slightly warmer temperatures are possible Monday even as a southeast
to easterly upslope flow persists across western Kansas.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 618 AM CDT Fri May 13 2016
Gusty southwest winds will develop this morning ahead of a
surface cold front which will move out of Nebraska and into
western Kansas by the early afternoon. Models were in decent
agreement with this frontal boundary to be located near GCK and
HYS around 18z and then by 21z this front is forecast to be
located southeast of DDC. As this front passes the southwest winds
will shift to the north at around 20 knots. Scattered
thunderstorms will be possible by late day along this front but at
this time it appears any thunderstorm that does develop late day
will be south and east of all taf sites. HRRR and NAM all
indicated VFR conditions.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 83 44 60 43 / 20 10 10 30
GCK 82 43 60 43 / 10 10 10 30
EHA 83 45 60 43 / 10 10 10 30
LBL 85 46 60 43 / 20 20 10 30
HYS 78 41 59 42 / 10 10 10 30
P28 83 48 60 46 / 30 30 10 20
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...JJohnson
LONG TERM...JJohnson
AVIATION...Burgert
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
556 AM CDT FRI MAY 13 2016
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 325 AM CDT FRI MAY 13 2016
In the short term, the forecast problem of the day is the extent and
timing of thunderstorm chances this afternoon across northeast
Kansas. Northwest flow aloft prevails across the central and western
CONUS this morning. A shortwave is forecast to amplify today as it
dives southeast into the central US. Latest water vapor imagery
confirms this with an impressive vort max just north of the Canadian
border north of North Dakota. A surface low over eastern Wyoming at
06 UTC is forecast to move quickly southeast in association with the
applying upper trough reaching eastern Iowa by 21 UTC today with a
trailing cold front across northern Missouri and eastern Kansas. The
front should enter our forecast area around 18 UTC and exit around
00 UTC/Sat. The models are in good agreement concerning the timing
of the front. All of the convection resolving high-resolution
models develop thunderstorms along the front over eastern Kansas
between 18-21 UTC and exiting the area shortly after 00 UTC. The
main concern this morning is low-level moisture. Moisture from the
Gulf of Mexico is currently blocked by a surface ridge over the
southern plains. The models all bring a narrow ribbon of moisture
rapidly northeast into eastern Kansas just ahead of the front. This
will likely occur to some extent. Thinking is that there should be
decent coverage of initially high-based, but surface based storms
which should develop and increasingly favorable deep shear
environment. It will be interesting to see if there will be any low-
level backing of the winds which would result in better low-level
shear. At this point, the primary risk should be hail and wind.
Given the deep shear, the storms have a good chance being organized
with discrete storms early before developing cold pools into a
linear system.
Strong cold advection tonight which will result in sharply lower
temperatures. Will probably see mid/high clouds late due to
channeled vorticity aloft, but will not mention precipitation at
this time. The airmass looks dry below 700 MB.
.LONG TERM...(Saturday through Thursday)
Issued at 325 AM CDT FRI MAY 13 2016
Northwest flow aloft will be in place through the weekend, with
multiple embedded shortwaves bringing chances for precipitation.
Saturday morning may be met with only light showers across the area,
given that air nearest to the surface is relatively dry. Surface
flow from the north will aid in keeping temperatures much cooler
than recently seen, with highs in the low 60s. Surface high
pressure moves in from the northwest during the day Saturday, moving
over NE Kansas overnight. Clouds streaming in from the northwest
will move over central and east central Kansas by early morning.
With time to cool before clouds move in, lows are still expected to
be in the low 40s, even lower in far northeast Kansas where cloud
cover will not be as prominent. Precipitation chances start again
on Sunday as a series of shortwaves ahead of an upper level low
located over the northwest CONUS move near Kansas. Chances increase
from Sunday night though Tuesday as ascent ahead of the low and
multiple shortwaves bring chances for primarily rain showers, as
instability is very limited due to the cooler temperatures in place.
This system is forecast to move east and out of the area Tuesday
night, allowing for a brief period of dry conditions Wednesday into
Wednesday night. A southern stream trough will bring the next
chances for rain and thunderstorms to the area Thursday and Friday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday Morning)
Issued at 550 AM CDT FRI MAY 13 2016
Keep mention of LLWS at MHK based on the current observation and
model forecast sounding this morning until winds mixed to the
surface. Timing of the cdfnt this afternoon looks on track. There
is enough confidence of thunderstorms over eastern KS to add a
tempo thunderstorm group for 2 hours this afternoon with fropa.
The timing may need to be adjusted slightly moving forward.
Although not mentioned in forecast, thunderstorms will have the
potential to produce downburst winds.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Johnson
LONG TERM...Heller
AVIATION...Johnson
Area Forecast Discussion
National Weather Service Wichita KS
507 AM CDT FRI MAY 13 2016
.SHORT TERM...(Today through tonight)
Issued at 329 AM CDT Fri May 13 2016
Forecast highlights the next 7-10 days focus around severe storm
chances this afternoon-evening, much cooler this weekend into
early/mid next week, and increasing precipitation chances late
weekend into early next week.
A strong cold front, currently analyzed across Wyoming and South
Dakota, will surge south across the Heartland today, supporting
increasing thunderstorm chances after roughly 3pm this afternoon.
Initiation will likely occur first over northeast Kansas closer to
upper forcing, with isolated to widely scattered thunderstorms
zippering down the cold front to the southwest, generally along
and north of the Highway 50 corridor. Despite only modest moisture
return (boundary layer dewpoints low-mid 50s), steep mid-level
lapse rates should support MLCAPE values up to 1500 j/kg. This in
concert with 40-50 kts of deep layer shear should support a
handful of strong-severe storms. Main threats will likely be large
hail and damaging winds. Despite some hints at modest low-level
shear per cyclonically looping hodographs, tornado threat should
be minimal due to relatively high cloud bases. Activity will then
move into southern and southeast Kansas during the evening,
likely diminishing after dark due to limited moisture/instability,
lack of low-level jet and best forcing remaining well northeast of
the region.
ADK
.LONG TERM...(Saturday through Thursday)
Issued at 329 AM CDT Fri May 13 2016
Of particular note will be the much cooler air in wake of this
front. After high temperatures in the 70s-80s today, daytime
temperatures in the 50s-60s are expected Saturday through Tuesday,
about 15-20 degrees cooler than normal. Consequently, could be
flirting with record cool high temperatures. Furthermore, expect
shower/thunderstorm chances to increase from the southwest
especially by sunday and Sunday night, likely becoming
widespread/numerous for Monday into early Tuesday, as an upper
shortwave approaches from the southwest. All-in-all, concentrated
severe weather probabilities should remain highest generally south
of the KS/OK border, although increasing elevated moisture and
instability may support strong storms over southern Kansas late
Sunday night through Monday evening. After a break Tuesday night
and Wednesday, medium range model consensus supports increasing
precipitation chances for late week, along with a return to near
normal temperatures, as a western conus trough approaches.
ADK
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 459 AM CDT Fri May 13 2016
Main aviation hazards: low-level wind shear early this morning,
then potential for a few strong storms this afternoon.
A 40-45 knot south-southwesterly low-level jet may result in low-
level wind shear in South-Central Kansas and the Flint Hills early
this morning, with very light winds at the surface until about
14z.
A strong cold front will push southeastward through
Central/Southeastern Kansas this afternoon into early this
evening. Gusty southwesterly winds ahead of the front, will shift
to gusty northwesterly behind the frontal passage. Feel scattered
storms will develop initially over northeastern Kansas where cap
will be breached first, with development proceeding southwestward
into South-Central/Southeast Kansas toward mid afternoon into
early evening, before storms clear out of southeast Kansas. Hail
and strong wind gusts will accompany the strongest storm cores.
North-northeasterly winds will diminish later this evening.
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 82 46 62 46 / 40 40 10 20
Hutchinson 82 44 62 43 / 30 20 10 20
Newton 81 43 59 44 / 40 40 10 10
ElDorado 81 45 61 45 / 50 50 10 10
Winfield-KWLD 83 47 62 47 / 40 40 10 20
Russell 79 42 62 43 / 10 10 10 20
Great Bend 81 42 62 43 / 20 10 10 20
Salina 81 43 63 43 / 30 10 20 10
McPherson 81 42 62 42 / 30 20 10 20
Coffeyville 81 48 62 46 / 20 30 10 10
Chanute 81 46 62 44 / 40 40 10 10
Iola 80 46 62 43 / 50 50 20 10
Parsons-KPPF 81 47 62 45 / 20 40 10 10
&&
.ICT Watches/Warnings/Advisories...
None.
&&
$$
SHORT TERM...ADK
LONG TERM...ADK
AVIATION...JMC
Area Forecast Discussion
National Weather Service Goodland KS
330 AM MDT FRI MAY 13 2016
.SHORT TERM...(Today through Sunday night)
Issued at 330 AM MDT Fri May 13 2016
Today-tonight...cold front quickly moves south across the forecast
area before noon bringing north winds gusting to around 30 mph and
slowly decreasing temperatures from north to south through the day.
By late in the day winds will subside a bit closer to 10 to 15 mph
from the north-northeast. Not much in the way of cloudiness til late
afternoon unless cirrus currently northwest of us moves down. High
temperatures will range from the mid 60s to near 70 along/north of
the KS/NE border to the mid/upper 70s in the Tribune and Leoti
areas. For tonight a 1030mb sfc high moves down from the north
allowing overnight low temperatures to drop into the mid 30s to
around 40. Will have to watch for possible impacts of quickly
increasing cloudiness on the overnight lows as this will prevent
less than ideal radiational cooling with the light sfc winds and
sfc high over the area. A few rain showers are possible from near
Yuma to Oberlin and Norton northward after midnight where some mid
level frontogenesis exists within a layer of moisture in the
700-500 layer.
Saturday-Saturday night...Plenty of moisture below 700mb suggesting
a mostly cloudy to cloudy sky through the period. The mid levels of
the atmosphere dry out thus am not forecasting any precipitation
during the day. It will be rather cool with afternoon temperatures
in the mid 50s to near 60. For Saturday night the mid levels of the
atmosphere moisten up after midnight while the lower levels remain
moist through the night. As a result have precipitation chances
slowly increasing after midnight with some light rain showers
possible. Low temperatures in the upper 30s to low 40s.
Sunday-Sunday night...Will continue with slight chance/chance pops
during the morning and early afternoon before some drier air aloft
moves in from the west bringing an end to the rain showers by days
end. The GFS model hangs on to some slight chance pops across the
far east while the NAM pushes the better moisture out of the area
late in the day. Surface pressure gradient increases between
departing sfc high and low pressure along the front range. This will
create breezy to windy southeast winds across much of the area by
late morning through late afternoon. Afternoon temperatures will
remain well below normal with low to mid 50s. For Sunday night
another weather disturbance moves into the area from the west
creating another chance for light rain showers. Low temperatures in
the low to mid 40s.
.LONG TERM...(Monday through Thursday)
Issued at 224 AM MDT Fri May 13 2016
The area of low pressure situated over the northern rockies will
slide southward on Monday with both the ECMWF and GFS in good
agreement on this solution. PoPs will be in the 50 to 70 percent
range on Monday and into Monday night/Tuesday morning. Instability
is marginal at this point with the exception of the south and
southwest portions of the region. A few strong to perhaps severe
storms are possible in the southern and southwestern portions of
the CWA as CAPE will be in the 1200 to 2000 J/KG range with bulk
shear in the 30 to 40 knot range. I went with 50 to 60 percent
PoPs early Tuesday morning with diminishing precip chances
thereafter as the H5 low and associated trough slide further
south, taking the better rain chances with it. For Tuesday night,
slight PoPs are in the forecast early however things should dry
out by Wednesday morning and remain dry through the early
afternoon. A weak north/south oriented boundary in eastern
Colorado will provide a focus for potential thunderstorm
development during the mid to late afternoon hours on Wednesday.
Precipitation chances diminish as we head through the day on
Thursday with slight chances through around midday mainly in the
eastern half of the CWA.
Temperatures will remain below normal Monday through Wednesday with
daytime highs only reaching into the 50s and 60s. Warmer and more
seasonal highs return for Thursday with highs in the 70s. Lows will
be in the lower to middle 40s each night.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 330 AM MDT Fri May 13 2016
For KGLD and KMCK...vfr conditions expected through the period.
Both terminals will have a cold front move through this morning
creating northerly winds gusting to 30kts or so. By mid to late
afternoon winds slowly veer to the northeast while also slowly
decreasing. For tonight winds remain light from the northeast
(KMCK) and east (KGLD) at speeds under 10kts. Both terminals may
see some cirrus during the day with some increase in low and mid
level cloudiness very late in the day through tonight. KMCK may
experience some light rain showers from 6z through the rest of the
taf period.
&&
.GLD Watches/Warnings/Advisories...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...99
LONG TERM...TL
AVIATION...99
Area Forecast Discussion
National Weather Service Wichita KS
329 AM CDT FRI MAY 13 2016
.SHORT TERM...(Today through tonight)
Issued at 329 AM CDT Fri May 13 2016
Forecast highlights the next 7-10 days focus around severe storm
chances this afternoon-evening, much cooler this weekend into
early/mid next week, and increasing precipitation chances late
weekend into early next week.
A strong cold front, currently analyzed across Wyoming and South
Dakota, will surge south across the Heartland today, supporting
increasing thunderstorm chances after roughly 3pm this afternoon.
Initiation will likely occur first over northeast Kansas closer to
upper forcing, with isolated to widely scattered thunderstorms
zippering down the cold front to the southwest, generally along
and north of the Highway 50 corridor. Despite only modest moisture
return (boundary layer dewpoints low-mid 50s), steep mid-level
lapse rates should support MLCAPE values up to 1500 j/kg. This in
concert with 40-50 kts of deep layer shear should support a
handful of strong-severe storms. Main threats will likely be large
hail and damaging winds. Despite some hints at modest low-level
shear per cyclonically looping hodographs, tornado threat should
be minimal due to relatively high cloud bases. Activity will then
move into southern and southeast Kansas during the evening,
likely diminishing after dark due to limited moisture/instability,
lack of low-level jet and best forcing remaining well northeast of
the region.
ADK
.LONG TERM...(Saturday through Thursday)
Issued at 329 AM CDT Fri May 13 2016
Of particular note will be the much cooler air in wake of this
front. After high temperatures in the 70s-80s today, daytime
temperatures in the 50s-60s are expected Saturday through Tuesday,
about 15-20 degrees cooler than normal. Consequently, could be
flirting with record cool high temperatures. Furthermore, expect
shower/thunderstorm chances to increase from the southwest
especially by sunday and Sunday night, likely becoming
widespread/numerous for Monday into early Tuesday, as an upper
shortwave approaches from the southwest. All-in-all, concentrated
severe weather probabilities should remain highest generally south
of the KS/OK border, although increasing elevated moisture and
instability may support strong storms over southern Kansas late
Sunday night through Monday evening. After a break Tuesday night
and Wednesday, medium range model consensus supports increasing
precipitation chances for late week, along with a return to near
normal temperatures, as a western conus trough approaches.
ADK
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1142 PM CDT Thu May 12 2016
Main aviation concern will be storms along a strong cold front
Fri afternoon/evening.
Water vapor imagery shows shortwave energy diving southeast over
southern Manitoba. This feature will continue tracking southeast
into the northern Mississippi Valley into Fri morning and will
push a strong cold front into the Central Plains. Storms are
expected to develop along this feature this afternoon into the
evening for areas along and southeast of the KS Turnpike. Current
thinking is that sct storms will develop around 19-20z just NW of
the KS Turnpike, affecting KICT-KHUT first, with KCNU being
affected around 00z Sat. Hail to the size of quarters and 60 mph
winds will be possible with the stronger storms.
Lawson
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 82 46 62 46 / 40 40 10 20
Hutchinson 82 44 62 43 / 30 20 10 20
Newton 81 43 59 44 / 40 40 10 10
ElDorado 81 45 61 45 / 50 50 10 10
Winfield-KWLD 83 47 62 47 / 40 40 10 20
Russell 79 42 62 43 / 10 10 10 20
Great Bend 81 42 62 43 / 20 10 10 20
Salina 81 43 63 43 / 30 10 20 10
McPherson 81 42 62 42 / 30 20 10 20
Coffeyville 81 48 62 46 / 20 30 10 10
Chanute 81 46 62 44 / 40 40 10 10
Iola 80 46 62 43 / 50 40 20 10
Parsons-KPPF 81 47 62 45 / 20 40 10 10
&&
.ICT Watches/Warnings/Advisories...None.
&&
$$
SHORT TERM...ADK
LONG TERM...ADK
AVIATION...RBL
Area Forecast Discussion
National Weather Service Goodland KS
227 AM MDT FRI MAY 13 2016
.SHORT TERM...(This evening through Friday)
Issued at 135 PM MDT Thu May 12 2016
19Z Water vapor imagery indicated weak short wave ridging in place
across the area...although RAP analysis of dynamic tropopause
indicates a small scale trough entering into eastern Colorado.
While I do not think there will be a strong response to trough in
the afternoon, have noticed an area of enhanced cumulus clouds
along small convergence zone which may be a reflection of
approaching trough. HRRR beginning to latch on to this feature and
initiate convection after 21z, but with sparse coverage of QPF
even generous neighborhood methodologies keep pops at or below
10%. Would not expect severe convection in this case, but will
need to be monitored.
Another very conditional threat for thunderstorms exists around
12z where area of persistent warm air advection may provide
enough ascent to lift a parcel or two to saturation. Should this
occur, 500 to 1000 j/kg available that may provide an elevated
threat. Based on current data only a small minority of available
data suggest this will occur and with 70 to 100 mb condensation
pressure deficits in place have my doubts that forcing will be
sufficient for storm initiation.
On Friday...cold front will slide south over the area bringing
gusty northerly winds and cooler temperatures. Expect temps to
near 80 across southern zones while points in the north may
struggle to reach 70. Initial frontal passage should be dry with
little moisture available to work with.
.LONG TERM...(Monday through Thursday)
Issued at 224 AM MDT Fri May 13 2016
The area of low pressure situated over the northern rockies will
slide southward on Monday with both the ECMWF and GFS in good
agreement on this solution. PoPs will be in the 50 to 70 percent
range on Monday and into Monday night/Tuesday morning. Instability
is marginal at this point with the exception of the south and
southwest portions of the region. A few strong to perhaps severe
storms are possible in the southern and southwestern portions of
the CWA as CAPE will be in the 1200 to 2000 J/KG range with bulk
shear in the 30 to 40 knot range. I went with 50 to 60 percent
PoPs early Tuesday morning with diminishing precip chances
thereafter as the H5 low and associated trough slide further
south, taking the better rain chances with it. For Tuesday night,
slight PoPs are in the forecast early however things should dry
out by Wednesday morning and remain dry through the early
afternoon. A weak north/south oriented boundary in eastern
Colorado will provide a focus for potential thunderstorm
development during the mid to late afternoon hours on Wednesday.
Precipitation chances diminish as we head through the day on
Thursday with slight chances through around midday mainly in the
eastern half of the CWA.
Temperatures will remain below normal Monday through Wednesday with
daytime highs only reaching into the 50s and 60s. Warmer and more
seasonal highs return for Thursday with highs in the 70s. Lows will
be in the lower to middle 40s each night.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1126 PM MDT Thu May 12 2016
VFR conditions for both taf sites KGLD/KMCK. Mainly SKC thru
midday Friday...then increasing scattered mid/high clouds.
Winds SSW around 10kts through 12z Friday...then shifting back to
the NNW and increasing to 10-20kts...with gusts near 30kts after
18z Friday. KGLD may see winds continue to shift to the NE around
10kts by 04z Saturday.
Low Level Wind Shear(LLWS)...at 2000ft AGL...240 degrees 40-45kts.
For KGLD...08z-12z Friday. For KMCK...07z-14z Friday.
&&
.GLD Watches/Warnings/Advisories...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...TL
AVIATION...JN
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
322 AM CDT FRI MAY 13 2016
.SHORT TERM...(Today and Tonight)
Issued at 321 AM CDT FRI MAY 13 2016
A mid-level upper trough was moving through Kansas early this
morning. The wave has very little moisture to work with so expect
mid clouds to exit the area this morning. After the shortwave
passes, plenty of large scale subsidence today and tonight. The
surface high is forecast to move through Kansas today with the ridge
axis cross our forecast area this evening. After the early morning
clouds depart, expect sunny skies and mild temperatures today. We
should mix fairly deep this afternoon and northwest winds should
reach the 10-20 mph range. The ridge passes this evening and
southwest boundary layer flow develops. With the surface ridge
across the southern plains late tonight, low-level moisture will be
slow to return.
.LONG TERM...(Saturday through Thursday)
Issued at 321 AM CDT FRI MAY 13 2016
Northwest flow aloft will be in place through the weekend, with
multiple embedded shortwaves bringing chances for precipitation.
Saturday morning may be met with only light showers across the area,
given that air nearest to the surface is relatively dry. Surface
flow from the north will aid in keeping temperatures much cooler
than recently seen, with highs in the low 60s. Surface high
pressure moves in from the northwest during the day Saturday, moving
over NE Kansas overnight. Clouds streaming in from the northwest
will move over central and east central Kansas by early morning.
With time to cool before clouds move in, lows are still expected to
be in the low 40s, even lower in far northeast Kansas where cloud
cover will not be as prominent. Precipitation chances start again
on Sunday as a series of shortwaves ahead of an upper level low
located over the northwest CONUS move near Kansas. Chances increase
from Sunday night though Tuesday as ascent ahead of the low and
multiple shortwaves bring chances for primarily rain showers, as
instability is very limited due to the cooler temperatures in place.
This system is forecast to move east and out of the area Tuesday
night, allowing for a brief period of dry conditions Wednesday into
Wednesday night. A southern stream trough will bring the next
chances for rain and thunderstorms to the area Thursday and Friday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1135 PM CDT THU MAY 12 2016
Not much change to the previous forecast, expect to go ahead and
add a mention of LLWS at MHK. Think the low level jet will
move into central KS just before sunrise while the nocturnal
inversion is still in place. Otherwise TS still appear likely
across eastern KS with the FROPA.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Johnson
LONG TERM...Heller
AVIATION...Wolters
Area Forecast Discussion
National Weather Service Dodge City KS
102 AM CDT FRI MAY 13 2016
...UPDATE TO LONG TERM...
.SHORT TERM...(Today and tonight)
Issued at 1230 AM CDT Fri May 13 2016
Precip chances return late today as short range models indicate an
upper level shortwave trough cycling southeast across the Upper
Midwest, sending an attendant cold front southward across the
Central Plains. Meanwhile, a recently re-established low level
southerly flow will begin to slowly draw moisture up into central
and portions of southwest Kansas with surface dewpoints climbing
well into the 50s(F) ahead of the approaching cold front. Although
the flow aloft will remain less than favorable with a strong jet
core staying off to our northeast across the Upper Midwest, it
will be strong enough to help support shower and thunderstorm
development late this afternoon as capping weakens while the front
pushes into more readily available moisture. Ample instability
with SBCAPE in excess of 2,000 J/KG and favorable deep layer shear
will increase the potential for strong to marginally severe
thunderstorms into early to mid evening across south central
Kansas.
As for temperatures, surface high pressure drifting southeast into
the Ark-La-Tex Region while a surface low approaching from the
northwest deepens will create a fairly strong southwest flow across
western Kansas later this morning into early afternoon. This will
enhance warm air advection raising H85 temperatures into the mid
and upper teens(C) across central Kansas to a little above 20C in
extreme southwest Kansas. With fairly steep lapse rates developing
by this afternoon ahead of the front, look for highs well up into
the 80s(F) across central and much of southwest Kansas. Colder air
will spill southward into western Kansas late tonight dropping
temperatures into the 40s(F) for lows by daybreak Saturday
morning.
.LONG TERM...(Saturday through Thursday)
Issued at 100 AM CDT Fri May 13 2016
Precip chances dwindle Saturday as much drier air filters southwest
into western Kansas behind a cold front plunging further south into
north Texas. Precip chances return Sunday as a series of H5 vort
maxima kick out of the Colorado Rockies into the Western High
Plains within a westerly flow aloft. Surface high pressure pushing
east across the Central Plains will return a southeasterly upslope
flow to western Kansas, and in turn, increase moisture somewhat
across southwest and west central Kansas. As the H5 vort maxima
move into the high plains, showers and thunderstorms are expected
to develop in the vicinity of a stationary frontal boundary/trough
in eastern Colorado, then spread eastward into western Kansas
during the day Sunday and possibly into Monday.
Much cooler temperatures are on the way Saturday as colder air
associated with a surface high moving across the Northern Plains
surges southward into western Kansas. The GFS and ECMWF show H85
temperatures dropping as low as the mid single digits(C) across
central Kansas to near 10C in extreme southwest Kansas. Expect highs
in the upper 50s(F) to the lower 60s(F) Saturday afternoon. Similar
highs can be expected Sunday with the cooler air mass slow to erode
as surface high pressure drops southeast across the Central Plains.
Slightly warmer temperatures are possible Monday even as a southeast
to easterly upslope flow persists across western Kansas.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1200 AM CDT Fri May 13 2016
VFR conditions will prevail at all TAF sites through late this
afternoon. Southerly winds 5 to 15kt will persist across western
Kansas overnight as surface high pressure moves southward across
Oklahoma. Winds will turn southwesterly increasing to around 20 to
30kt mid to late morning as surface low pressure developing across
the high plains strengthens ahead of an approaching cold front. The
cold front will move across western Kansas this afternoon turning
winds northerly 15 to 25kt.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 55 83 44 60 / 0 20 10 10
GCK 54 82 43 60 / 0 10 10 10
EHA 53 83 45 60 / 0 10 10 10
LBL 54 85 46 60 / 0 20 20 10
HYS 53 78 41 59 / 0 10 10 10
P28 53 83 48 60 / 0 30 30 10
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...JJohnson
LONG TERM...JJohnson
AVIATION...JJohnson
Area Forecast Discussion
National Weather Service Dodge City KS
102 AM CDT FRI MAY 13 2016
...UPDATE TO LONG TERM...
.SHORT TERM...(Today and tonight)
Issued at 1230 AM CDT Fri May 13 2016
Precip chances return late today as short range models indicate an
upper level shortwave trough cycling southeast across the Upper
Midwest, sending an attendant cold front southward across the
Central Plains. Meanwhile, a recently re-established low level
southerly flow will begin to slowly draw moisture up into central
and portions of southwest Kansas with surface dewpoints climbing
well into the 50s(F) ahead of the approaching cold front. Although
the flow aloft will remain less than favorable with a strong jet
core staying off to our northeast across the Upper Midwest, it
will be strong enough to help support shower and thunderstorm
development late this afternoon as capping weakens while the front
pushes into more readily available moisture. Ample instability
with SBCAPE in excess of 2,000 J/KG and favorable deep layer shear
will increase the potential for strong to marginally severe
thunderstorms into early to mid evening across south central
Kansas.
As for temperatures, surface high pressure drifting southeast into
the Ark-La-Tex Region while a surface low approaching from the
northwest deepens will create a fairly strong southwest flow across
western Kansas later this morning into early afternoon. This will
enhance warm air advection raising H85 temperatures into the mid
and upper teens(C) across central Kansas to a little above 20C in
extreme southwest Kansas. With fairly steep lapse rates developing
by this afternoon ahead of the front, look for highs well up into
the 80s(F) across central and much of southwest Kansas. Colder air
will spill southward into western Kansas late tonight dropping
temperatures into the 40s(F) for lows by daybreak Saturday
morning.
.LONG TERM...(Saturday through Thursday)
Issued at 100 AM CDT Fri May 13 2016
Precip chances dwindle Saturday as much drier air filters southwest
into western Kansas behind a cold front plunging further south into
north Texas. Precip chances return Sunday as a series of H5 vort
maxima kick out of the Colorado Rockies into the Western High
Plains within a westerly flow aloft. Surface high pressure pushing
east across the Central Plains will return a southeasterly upslope
flow to western Kansas, and in turn, increase moisture somewhat
across southwest and west central Kansas. As the H5 vort maxima
move into the high plains, showers and thunderstorms are expected
to develop in the vicinity of a stationary frontal boundary/trough
in eastern Colorado, then spread eastward into western Kansas
during the day Sunday and possibly into Monday.
Much cooler temperatures are on the way Saturday as colder air
associated with a surface high moving across the Northern Plains
surges southward into western Kansas. The GFS and ECMWF show H85
temperatures dropping as low as the mid single digits(C) across
central Kansas to near 10C in extreme southwest Kansas. Expect highs
in the upper 50s(F) to the lower 60s(F) Saturday afternoon. Similar
highs can be expected Sunday with the cooler air mass slow to erode
as surface high pressure drops southeast across the Central Plains.
Slightly warmer temperatures are possible Monday even as a southeast
to easterly upslope flow persists across western Kansas.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1200 AM CDT Fri May 13 2016
VFR conditions will prevail at all TAF sites through late this
afternoon. Southerly winds 5 to 15kt will persist across western
Kansas overnight as surface high pressure moves southward across
Oklahoma. Winds will turn southwesterly increasing to around 20 to
30kt mid to late morning as surface low pressure developing across
the high plains strengthens ahead of an approaching cold front. The
cold front will move across western Kansas this afternoon turning
winds northerly 15 to 25kt.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 55 83 44 60 / 0 20 10 10
GCK 54 82 43 60 / 0 10 10 10
EHA 53 83 45 60 / 0 10 10 10
LBL 54 85 46 60 / 0 20 20 10
HYS 53 78 41 59 / 0 10 10 10
P28 53 83 48 60 / 0 30 30 10
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...JJohnson
LONG TERM...JJohnson
AVIATION...JJohnson
Area Forecast Discussion
National Weather Service Dodge City KS
1230 AM CDT FRI MAY 13 2016
...UPDATE TO SHORT TERM...
.SHORT TERM...(Today and tonight)
Issued at 1230 AM CDT Fri May 13 2016
Precip chances return late today as short range models indicate an
upper level shortwave trough cycling southeast across the Upper
Midwest, sending an attendant cold front southward across the
Central Plains. Meanwhile, a recently re-established low level
southerly flow will begin to slowly draw moisture up into central
and portions of southwest Kansas with surface dewpoints climbing
well into the 50s(F) ahead of the approaching cold front. Although
the flow aloft will remain less than favorable with a strong jet
core staying off to our northeast across the Upper Midwest, it
will be strong enough to help support shower and thunderstorm
development late this afternoon as capping weakens while the front
pushes into more readily available moisture. Ample instability
with SBCAPE in excess of 2,000 J/KG and favorable deep layer shear
will increase the potential for strong to marginally severe
thunderstorms into early to mid evening across south central
Kansas.
As for temperatures, surface high pressure drifting southeast into
the Ark-La-Tex Region while a surface low approaching from the
northwest deepens will create a fairly strong southwest flow across
western Kansas later this morning into early afternoon. This will
enhance warm air advection raising H85 temperatures into the mid
and upper teens(C) across central Kansas to a little above 20C in
extreme southwest Kansas. With fairly steep lapse rates developing
by this afternoon ahead of the front, look for highs well up into
the 80s(F) across central and much of southwest Kansas. Colder air
will spill southward into western Kansas late tonight dropping
temperatures into the 40s(F) for lows by daybreak Saturday
morning.
.LONG TERM...(Friday night through Thursday)
Issued at 234 PM CDT Thu May 12 2016
Any thunderstorms that develop Friday afternoon should quickly
push south out of the area by midnight with mostly clear skies
expected for the remainder of Friday night. Cloudiness and low
level moisture increases Saturday morning as winds shift to the
southeast bringing an up-slope component of the wind. Mostly
cloudy skies are anticipated by Saturday afternoon and continue
through the early part of next week. Precipitation chances
increase Saturday night as moist upslope flow continue. These
precipitation chances will continue into the early part of next
week as a series of weak disturbances move into the area. Extended
models suggest rain chances to also continue into the remainder of
next week but confidence is low that this pattern will continue
that long. As for temperatures, cooler air will filter into
western Kansas with highs this weekend only reaching to around 60
degrees. In fact, a few places may not make it out of the 50s on
Sunday. Lows during the weekend look to dip into the lower 40s
Saturday morning with mid 40s Sunday morning. Slightly warmer
temperatures are expected early next week but only top out in the
low to mid 60s with lows in the 40s to lower 50s.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1200 AM CDT Fri May 13 2016
VFR conditions will prevail at all TAF sites through late this
afternoon. Southerly winds 5 to 15kt will persist across western
Kansas overnight as surface high pressure moves southward across
Oklahoma. Winds will turn southwesterly increasing to around 20 to
30kt mid to late morning as surface low pressure developing across
the high plains strengthens ahead of an approaching cold front. The
cold front will move across western Kansas this afternoon turning
winds northerly 15 to 25kt.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 55 83 44 58 / 0 20 10 10
GCK 54 82 43 59 / 0 10 10 10
EHA 53 83 45 59 / 0 10 10 10
LBL 54 85 46 59 / 0 20 20 10
HYS 53 78 41 58 / 0 10 10 10
P28 53 83 48 60 / 0 30 30 10
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...JJohnson
LONG TERM...Hovorka_42
AVIATION...JJohnson
Area Forecast Discussion
National Weather Service Goodland KS
1126 PM MDT THU MAY 12 2016
.SHORT TERM...(This evening through Friday)
Issued at 135 PM MDT Thu May 12 2016
19Z Water vapor imagery indicated weak short wave ridging in place
across the area...although RAP analysis of dynamic tropopause
indicates a small scale trough entering into eastern Colorado.
While I do not think there will be a strong response to trough in
the afternoon, have noticed an area of enhanced cumulus clouds
along small convergence zone which may be a reflection of
approaching trough. HRRR beginning to latch on to this feature and
initiate convection after 21z, but with sparse coverage of QPF
even generous neighborhood methodologies keep pops at or below
10%. Would not expect severe convection in this case, but will
need to be monitored.
Another very conditional threat for thunderstorms exists around
12z where area of persistent warm air advection may provide
enough ascent to lift a parcel or two to saturation. Should this
occur, 500 to 1000 j/kg available that may provide an elevated
threat. Based on current data only a small minority of available
data suggest this will occur and with 70 to 100 mb condensation
pressure deficits in place have my doubts that forcing will be
sufficient for storm initiation.
On Friday...cold front will slide south over the area bringing
gusty northerly winds and cooler temperatures. Expect temps to
near 80 across southern zones while points in the north may
struggle to reach 70. Initial frontal passage should be dry with
little moisture available to work with.
.LONG TERM...(Friday night through Thursday)
Issued at 231 PM MDT Thu May 12 2016
Friday night-Saturday: The cold front should be south of our cwa
by Friday evening with CAA through Saturday. Models are still
showing positive 850-700mb frontogenesis late Friday night, and as
was the case the last few days moisture will be a limiting factor
on coverage. I kept slight chance PoPs (showers) limited to our
northeast, though NAM/SREF are showing the possibility for a
secondary area of light precip in our far west/southwest (possibly
drizzle near frontal zone). I was less confidence in including
drizzle or light showers across the rest of our CWA due to the
frontal position and current consensus. Any activity should be out
of the area by Saturday morning with a dry period during the day
Saturday. The combination of lingering cloud cover and a much
colder air mass will lead to highs 10-20F cooler (50s to near
60F).
Saturday night-Thursday: Models continue to support an active/wet
pattern through the extended period. As has been the case smaller
scale details are still somewhat uncertain, though there is enough
consistency/consensus to support higher PoPs Sunday night through
Monday night (likely). A recent trend has been for the GFS and GEFS
to move towards the ECMWF on Monday regarding frontal position
(further south from our CWA). This position significantly lowers
potential for severe thunderstorms, though it still is close
enough that there could still be a limited threat in our south
Monday afternoon/evening. By Tuesday night there is a lot more
spread between models Tuesday through Thursday as a result of a
progressive NW pattern remain in place despite the building ridge
in the west. I kept slight chance/chance pops in place with chance
PoPs on periods of better (incidental) overlap.
Temperatures through most of the extended should remain below
normal, with a recovery in highs Wed/Thu in response to rising
heights. Consensus supports 50s/Low 60s Sunday through Tuesday,
then mid/upper 60s Wednesday, and 70s on Thursday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1126 PM MDT Thu May 12 2016
VFR conditions for both taf sites KGLD/KMCK. Mainly SKC thru
midday Friday...then increasing scattered mid/high clouds.
Winds SSW around 10kts through 12z Friday...then shifting back to
the NNW and increasing to 10-20kts...with gusts near 30kts after
18z Friday. KGLD may see winds continue to shift to the NE around
10kts by 04z Saturday.
Low Level Wind Shear(LLWS)...at 2000ft AGL...240 degrees 40-45kts.
For KGLD...08z-12z Friday. For KMCK...07z-14z Friday.
&&
.GLD Watches/Warnings/Advisories...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...DR
AVIATION...JN
AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
643 AM CDT FRI MAY 13 2016
.UPDATE...
Issued at 643 AM CDT Fri May 13 2016
The going forecast is on track, so little change was made with
this update. Overnight precipitation has largely exited into SD as
of 1130 UTC. Meanwhile, a few spotty and low-topped echoes have
been observed in cyclonic flow over western and central ND during
the last two hours, and a brief rain and snow shower was reported
at KISN. However, after some deliberation we decided to leave the
chance of precipitation at 10 percent this morning and thus forgo
any mention of weather since coverage looks less than 20 percent
at this time. We will continue to re-evaluate that the next few
hours though.
&&
.SHORT TERM...(Today and tonight)
Issued at 355 AM CDT Fri May 13 2016
Confidence is high that a widespread freeze will occur across all
of western and central ND tonight and Saturday morning.
As of 08 UTC, the frontogenetically-induced band of rain and snow
in southern ND is sinking toward the SD border. A time-series of
VAD wind profile data from the KBIS WSR-88D has shown a definite
deepening of cold air since about 06 UTC, supporting a southward
displacement of the active frontogenetical zone and ageostrophic
circulation. Recent RAP and HRRR radar simulations concur and
shift the rest of the precipitation out of the state by 12 UTC.
For today, breezy to windy and cool weather is expected as deep-
layer flow turns more sharply northwesterly behind the overnight
shortwave trough passage. Forecast highs, per the 00 UTC multi-
model consensus, are only in the 40s F. Mid-level winds based in
the 850-MB layer will run close to 30 kt per the 00 UTC GFS and
ECMWF and 21 UTC SREF and forecast soundings support a well-mixed
layer extending to at least that depth, so gusts to 30 mph are in
the forecast. Note that we did not utilize the 00 UTC NAM or its
MOS (MET) guidance since it was an outlier with lower wind speeds
at 850 MB than the remainder of guidance. Finally, mean cyclonic
flow, cold air aloft, and turbulent mixing that extends into the
middle atmosphere is a good recipe for cumulus or stratocumulus
development, so cloud cover will likely be rather extensive for
most of the day. We considered adding some low shower chances to
central ND this afternoon since HRRR reflectivity simulations do
depict shallow cellular convection, but that same model does not
produce QPF. That lowered our confidence in any convection being
deep enough to actually reach the ground, so we maintained a dry
forecast for the time being.
Tonight will feature widespread sub-freezing temperatures thanks
to an anomalously cold air mass, light winds, and clearing skies
with the approach of a surface ridge. The ridge axis is forecast
by model guidance to extend from eastern MT across western ND, so
we expect the coldest temperatures in western parts of the state.
MOS-based guidance often handles these situations well so we did
weight the forecast toward it, yielding mid 20s F in southwestern
ND. Confidence in this scenario has been growing for several days
and is at a point where we decided to hoist a freeze warning for
all of western and central ND from 05 to 14 UTC (midnight to 9 am
CDT).
.LONG TERM...(Saturday through Thursday)
Issued at 355 AM CDT Fri May 13 2016
Cool weather will continue Saturday, with more potential frost on
Saturday night. A warming trend will begin thereafter and become
well-established next week.
The 00 UTC GFS and to a lesser extent the NAM and ECMWF suggest a
modest shortwave trough embedded in northwest flow will cross the
area on Saturday. We are carrying a chance of showers along and
east of the Highway 83 corridor in respect to that wave passage.
Mid-level temperatures will begin slowly modifying Saturday, and
highs will respond by pushing into the 50s F. Frost is possible
again Saturday night, though, and MOS guidance suggests southwest
ND could have yet another freeze.
Model guidance suggests 500-MB flow across the continental United
States will deamplify next week, heralding a warming trend across
the area. We relied on the normally-well-verifying model consensus
output for the long term forecast. That means forecast highs rise
steadily during the week from the lower to mid 60s F on Monday to
the lower to middle 70s F by Friday, when ridging may become more
pronounced ahead of a deepening Pacific northwest trough. We have
some modest shower chances in the forecast for much of next week
too given model-to-model and run-to-run uncertainty in shortwaves
embedded in the de-amplifying flow regime. However, taken at face
value the 00 UTC GFS and ECMWF actually suggest the period could
be more dry than wet.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 643 AM CDT Fri May 13 2016
Low VFR ceilings are expected across western and central ND today.
A few patches of MVFR ceilings are possible, too, especially this
morning, so we are carrying TEMPO groups advertising that in TAF
forecasts for KISN, KMOT, and KDIK. Northwest wind gusts up to 30
kt are expected today. Winds and clouds will both decrease quickly
this evening.
&&
.BIS Watches/Warnings/Advisories...
Freeze Warning from midnight CDT /11 PM MDT/ tonight to 9 AM CDT
/8 AM MDT/ Saturday for NDZ001>005-009>013-017>023-025-031>037-
040>048-050-051.
Frost Advisory until 9 AM CDT this morning for NDZ001>005-
009>013-017-021>023-025.
&&
$$
UPDATE...CJS
SHORT TERM...CJS
LONG TERM...CJS
AVIATION...CJS
AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
355 AM CDT FRI MAY 13 2016
.SHORT TERM...(Today and tonight)
Issued at 355 AM CDT Fri May 13 2016
Confidence is high that a widespread freeze will occur across all
of western and central ND tonight and Saturday morning.
As of 08 UTC, the frontogenetically-induced band of rain and snow
in southern ND is sinking toward the SD border. A time-series of
VAD wind profile data from the KBIS WSR-88D has shown a definite
deepening of cold air since about 06 UTC, supporting a southward
displacement of the active frontogenetical zone and ageostrophic
circulation. Recent RAP and HRRR radar simulations concur and
shift the rest of the precipitation out of the state by 12 UTC.
For today, breezy to windy and cool weather is expected as deep-
layer flow turns more sharply northwesterly behind the overnight
shortwave trough passage. Forecast highs, per the 00 UTC multi-
model consensus, are only in the 40s F. Mid-level winds based in
the 850-MB layer will run close to 30 kt per the 00 UTC GFS and
ECMWF and 21 UTC SREF and forecast soundings support a well-mixed
layer extending to at least that depth, so gusts to 30 mph are in
the forecast. Note that we did not utilize the 00 UTC NAM or its
MOS (MET) guidance since it was an outlier with lower wind speeds
at 850 MB than the remainder of guidance. Finally, mean cyclonic
flow, cold air aloft, and turbulent mixing that extends into the
middle atmosphere is a good recipe for cumulus or stratocumulus
development, so cloud cover will likely be rather extensive for
most of the day. We considered adding some low shower chances to
central ND this afternoon since HRRR reflectivity simulations do
depict shallow cellular convection, but that same model does not
produce QPF. That lowered our confidence in any convection being
deep enough to actually reach the ground, so we maintained a dry
forecast for the time being.
Tonight will feature widespread sub-freezing temperatures thanks
to an anomalously cold air mass, light winds, and clearing skies
with the approach of a surface ridge. The ridge axis is forecast
by model guidance to extend from eastern MT across western ND, so
we expect the coldest temperatures in western parts of the state.
MOS-based guidance often handles these situations well so we did
weight the forecast toward it, yielding mid 20s F in southwestern
ND. Confidence in this scenario has been growing for several days
and is at a point where we decided to hoist a freeze warning for
all of western and central ND from 05 to 14 UTC (midnight to 9 am
CDT).
.LONG TERM...(Saturday through Thursday)
Issued at 355 AM CDT Fri May 13 2016
Cool weather will continue Saturday, with more potential frost on
Saturday night. A warming trend will begin thereafter and become
well-established next week.
The 00 UTC GFS and to a lesser extent the NAM and ECMWF suggest a
modest shortwave trough embedded in northwest flow will cross the
area on Saturday. We are carrying a chance of showers along and
east of the Highway 83 corridor in respect to that wave passage.
Mid-level temperatures will begin slowly modifying Saturday, and
highs will respond by pushing into the 50s F. Frost is possible
again Saturday night, though, and MOS guidance suggests southwest
ND could have yet another freeze.
Model guidance suggests 500-MB flow across the continental United
States will deamplify next week, heralding a warming trend across
the area. We relied on the normally-well-verifying model consensus
output for the long term forecast. That means forecast highs rise
steadily during the week from the lower to mid 60s F on Monday to
the lower to middle 70s F by Friday, when ridging may become more
pronounced ahead of a deepening Pacific northwest trough. We have
some modest shower chances in the forecast for much of next week
too given model-to-model and run-to-run uncertainty in shortwaves
embedded in the de-amplifying flow regime. However, taken at face
value the 00 UTC GFS and ECMWF actually suggest the period could
be more dry than wet.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 355 AM CDT Fri May 13 2016
MVFR and IFR ceilings with light rain and snow will continue along
the ND/SD border through about 12 UTC. We are calling for VFR
conditions to prevail across western and central ND on Friday, but
there is a low probability of ceilings lowering to the MVFR range
in places once cloud cover thickens with the heating of the day.
Northwest wind gusts of 20 to 30 kt are expected on Friday, too.
&&
.BIS Watches/Warnings/Advisories...
Freeze Warning from midnight CDT /11 PM MDT/ tonight to 9 AM CDT
/8 AM MDT/ Saturday for NDZ001>005-009>013-017>023-025-031>037-
040>048-050-051.
Frost Advisory until 9 AM CDT this morning for NDZ001>005-
009>013-017-021>023-025.
&&
$$
SHORT TERM...CJS
LONG TERM...CJS
AVIATION...CJS
AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
1251 AM CDT FRI MAY 13 2016
.UPDATE...
Issued at 1251 AM CDT Fri May 13 2016
Frontogenetically-driven precipitation is sinking south of the
Interstate 94 corridor as of 0550 UTC, and while most guidance
has been too far south with that band through the late evening,
more recent RAP and HRRR simulations have done a more accurate job
assimilating radar trends than earlier. Thus, we were able to
slightly modify hourly precipitation chances through 10 UTC using
RAP and HRRR output. Moreover, we expanded the mention of a rain
and snow mix as web camera images from near Mott and Gladstone
have shown snow occurring there in the last 60 minutes.
UPDATE Issued at 930 PM CDT Thu May 12 2016
Latest HRRR time lag ensemble seems too far south on the
precipitation for the evening so have opted for the current
forecast with an update for radar trends. At 930 pm CDT the
precipitation area stretched from watford city southeast to
Bismarck. Current forecast looks good on this. Frost advisory
will go into effect late tonight north.
UPDATE Issued at 624 PM CDT Thu May 12 2016
Clouds increasing across west central North Dakota at this time
with NWS radars showing rain across eastern montana. trend looks
good with the precipitation chances this evening with rain
starting west central and southwest between 7 and 9 pm CDT. Mainly
updated current conditions via observations and satellite.
&&
.SHORT TERM...(This evening through Friday)
Issued at 122 PM CDT Thu May 12 2016
Widespread frost tonight north highlights the short term
forecast.
The 12 UTC global suites are in agreement on cold high pressure
building across the Northern Plains tonight through Friday. An
anomalously cold airmass is associated with this high with 850 mb
temperatures on the 00 UTC NAEFS ensemble mean falling to their
lowest 1 to 2.5 percentiles. Widespread lows in the lower to mid
30s are expected along and north of ND highway 200, and have
issued a frost advisory for these areas. South of ND highway 200,
sufficient cloud cover and a band of precipitation associated with
a low level baroclinic zone should hold temperatures in the mid to
upper 30s and prevent frost formation. However, this will have to
be monitored should clouds clear faster than currently forecast. A
few snowflakes may mix with the rain late tonight into early
Friday morning. Otherwise for Friday, given the cold airmass highs
only in the 40s are forecast.
.LONG TERM...(Friday night through Thursday)
Issued at 122 PM CDT Thu May 12 2016
A widespread freeze Friday night, with the continued threat for
frost Saturday and possibly Sunday nights highlight the long term
forecast.
As has been the consensus over the past several days. A widespread
freeze is possible across all of western and central North Dakota
Friday night into Saturday morning with cool high pressure in
place, generally clear skies and a cool start to begin with given
highs on Friday only forecast in the 40s. High pressure remains
across the Northern Plains on Saturday, marking another threat for
frost Saturday night into Sunday morning. Thereafter, the long
wave eastern CONUS trough that supported the intrusion of cold air
in the region under northwest flow aloft is forecast to deamplify
and propagate east, supporting a modest warm up to highs just
below average in the lower 60s Sunday into early next week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1251 AM CDT Fri May 13 2016
MVFR and IFR ceilings and perhaps visibilities in light rain and
snow will impact southwest and south central ND to the south of
Interstate 94 overnight. The worst of those conditions will stay
south of KDIK, KBIS, and KJMS. We are calling for VFR conditions
area-wide on Friday with northwest winds gusting from 20 to 30
kt, but there is a non-zero probability of MVFR ceilings
developing in the heating of the day.
&&
.BIS Watches/Warnings/Advisories...
Frost Advisory until 9 AM CDT this morning for NDZ001>005-
009>013-017-021>023-025.
&&
$$
UPDATE...CJS
SHORT TERM...AYD
LONG TERM...AYD
AVIATION...CJS
Area Forecast Discussion
National Weather Service Phoenix AZ
935 PM MST SAT MAY 14 2016
.SYNOPSIS...
Cooler air is beginning to move into the region as a low pressure
system in the northwest U.S. begins to deepen. Breezy conditions are
expected again for Sunday. Another Pacific weather system is
forecast to move into the southwestern states late Sunday through
Tuesday. This will provide even cooler temperatures along with slight
chances of thunderstorms mainly over northern and central Arizona.
Clearing skies with rebounding afternoon temperatures are forecast
for late next week.
&&
.DISCUSSION...
Clearing skies can be seen across southeastern California and the
western half of Arizona this evening. Earlier, a few thunderstorms
swept over the southeastern third of Arizona but that activity has
dissipated and pushed to the east. Low pressure system now over
Oregon continues to gradually deepen and spread its influence further
to the south. Models indicate this system will eventually drop down
towards the south, ultimately moving into northwest Arizona by
Tuesday evening. This will bring a slight chance for thunderstorms to
the region and keep relatively cooler air in place for a few days.
Rain chances are still on the low side but at least there`s a chance
for unsettled weather, particularly Tuesday afternoon through
Wednesday morning. Temperatures should start to climb back above
normals the rest of the week.
&&
.PREVIOUS DISCUSSION...
Latest satellite imagery shows several areas of cumulus congestus,
mainly concentrated across the Mogollon Rim, the CO Plateau and
portions of southeastern AZ. Isolated showers and thunderstorms have
developed, but are mainly relegated to the higher terrain near
Tucson and Flagstaff. Meanwhile, moisture values are running well
above average with dewpoints in the mid 40s. NAEFS PWAT percentiles
are also running above the 90th percentile, though ground based GPS-
IPW and TPW suggest PWATS are somewhat lower. The relatively moist
conditions have also kept temperatures at bay, which have generally
been running in the mid to upper 90s in the lower deserts. At Sky
Harbor Airport, the high has reached 100 degrees.
Preponderance of hi-res CAMs including the operational and
experimental HRRR continue to indicate that isolated convection will develop
across Gila County this afternoon and this evening. PoPs were increased
to around 10 percent in these areas, though in reality most precipitation
that falls will likely evaporate and not measure at the surface. Models
are in excellent agreement that much drier air will be transported
northeastward this evening and overnight, with the GEFS ensemble
mean indicating PWATS dropping as low as 0.40 inches. Consequently,
showers and thunderstorms will dissipate shortly after sunset.
&&
.AVIATION...
South-Central Arizona including KPHX...KIWA and KSDL...
Southeast California/Southwest Arizona including KIPL and KBLH...
A weak weather disturbance will continue to produce scattered
cumulus and altocumulus with broken-overcast cirrus this afternoon
before thinning out this evening. Over northern and southeastern
Arizona there will be isolated thunderstorms with some additional
weaker showers which will begin dissipating after sunset. Surface
winds will favor south and southwest directions through the evening
(gusts of 15-20 kts Phoenix area; 20-30 kts SE CA and SW AZ). Winds
will be stronger Sunday afternoon but with significantly less
cloudiness.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday...
A low pressure system will be centered over northwest Arizona on
Tuesday and Wednesday leading to a slight chance of thunderstorms
over south-central Arizona. Temperatures will be below normal with
light winds. The low exits Thursday before another system approaches
Friday and Saturday leading to breezy to windy conditions.
Temperatures will start off below normal Tuesday and Wednesday before
climbing back to normal by Friday. Humidities begin declining
Wednesday with Minimum values dipping to about 10% late in the week.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...Waters/Hirsch
PREVIOUS DISCUSSION...Kuhlman
AVIATION...AJ
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
1102 PM PDT SAT MAY 14 2016
.SYNOPSIS...
Breezy winds and near normal temperatures... with a chance of
precipitation through Monday and possibly lingering in the
mountains Tuesday afternoon. Offshore flow will make Wednesday and
Thursday the hottest days of the week. By Friday there will be an
increase in clouds and a cooling trend for the weekend.
&&
.UPDATE...
A cool day today with most coast and vlys temps coming in 4 to 8
degrees below normal. The marine layer is about 1800 feet and is
capped by a moderate inversion. The major player today is the
onshore flow which is an impressive 9.3 mb onshore to KDAG at 00Z
with this strong an east push there was very slow to no clearing
across the LA and VTA beaches. A little weak trof mixed the marine
layer out across the central coast and it will be slower to
reform. There will be plenty of low clouds over the VTA and LA
coasts and vlys but the SBA south coast will stay predominately
cloud free as the sun downer will keep the low clouds at bay.
The wind advisories for the Antelope Valley and the SBA south
coast are not too well but the SBA winds will likely pick up in
a few hours and there will be some local advisory level winds in
the AV but the stronger winds will be tomorrow.
Overall the current fcst is in good shape and there are no updates
planned.
&&
.SHORT TERM...(TDY-MON)
Upper level low currently moving eastward into Oregon and by
Sunday is centered over the Oregon/Idaho border. Around that time
it really becomes a split flow situation to stop its eastward
progression and the low begins to dig southward into Nevada over
the short term forecast. Models generally agree in placing the
center somewhere near Vegas on Tuesday. This trough pattern over
the west coast will result in little day to day changes through
the short term. Expect only minor fluctuations in the depth of the
marine layer and the extent of overnight/morning stratus. Onshore
pressure gradients will be strong enough to slow the pace of
afternoon clearing, with some immediate coastal areas staying in
the stratus through the afternoon. Northwest flow should help keep
the SBA coast clear at night. Had a few reports of drizzle in
Ventura County and overnight drizzle possibilities will continue
each night. Both the GFS and NAM swing a weak area of lift through
the area late tonight and tomorrow morning as the tail end of a
vort lobe around the upper low swings through. This may enhance
the chance of drizzle for tonight mainly over the LA County coast
and valleys. Decided to pull back on the slight chance of showers
in Los Angeles County coast and San Gabriel Valley for Sunday
afternoon/evening, keeping it instead limited to areas higher up
in the foothills.
High temperatures cool some on Sunday but in general will feel
the same. Models warm low levels a bit on Monday to bring a few
degrees warming mainly inland areas and a few degrees again on
Tuesday. Some far inland areas should even be back up above normal
for this time of year.
Winds will be an issue for the Antelope Valley and the Santa
Barbara south coast and adjacent foothills. Winds have been fairly
tame in the Antelope Valley so far but are expected to pick up
later this evening and stay elevated through Sunday night. For
winds in SBA County, gusty northwest winds will develop this
evening and again Sunday evening. Local numerical model indicates
stronger winds for Sunday evening. Another wind advisory will
likely be needed again for the same areas on Sunday night.
Have introduced a slight chance of showers over the eastern San
Gabriels for Tuesday afternoon/evening. With the position of the
closed upper low forecast to be near Vegas Tuesday, there could
be just enough instability and dynamics to produce some showers.
GFS and NAM both showing an area of negative lifted indicies along
with some CAPE. Moisture availability will be an issue however.
.LONG TERM...(TUE-FRI)
The closed upper low just to our NE is forecast to fill, open up,
and move east on Wednesday. Just enough in the way of height rises
to squeeze a few more degrees of warming Wednesday following
another night of coastal stratus (northwest flow should keep the
SBA south coast clear). Expecting above normal temperatures for
all but the immediate coast which will remain at or just below
normal.
By Thursday the next closed upper low forecast to dive down the
west coast will begin to increase our onshore pressure gradients,
thicken up the marine layer and stratus coverage, and start a
cooling trend that continues into Friday. The cooling will occur
first over inland areas Thursday then spread across the forecast
area Friday. Expect Saturday to be much the same as Friday as far
as marine layer and high temperatures. Some differences in the
east-west position of the low by 12z Saturday with the GFS along
the Oregon coast and the ECMWF further east over OR/ID border. But
this difference won`t impact the forecast for this long term
period.
&&
.AVIATION...15/06Z...
At 05z at KLAX... the inversion was about 1500 feet deep. The top
of the inversion was near 5150 feet with a temperature of thirteen
degrees Celsius.
Overall... Moderate confidence in the 06z TAFs. The reduced
confidence is primarily due to the uncertain timing of the low
cloud incursion and a bit due to uncertainty in the locations that
will be impacted. Most coastal and adjacent valley locations will
be impacted but there is up to a twenty percent chance that some
locations will remain VFR. Some wind shear in the KSBA vicinity
through 09z. Otherwise and elsewhere VFR conditions will prevail.
KLAX... Moderate confidence in the 06z TAF. The reduced
confidence is primarily due to the possibility of the height of
the marine layer fluctuating overnight. There is a 20 percent
chance of an east wind component 8-9 knots from 10Z-15z. There is
a thirty percent chance of no clearing Sunday afternoon.
Otherwise VFR conditions will prevail.
KBUR... Moderate confidence in the 06z TAF. The reduced
confidence is primarily due to the possibility of the height of
the marine layer fluctuating overnight. There is a twenty five
percent chance of the clearing delayed until 19z. Otherwise VFR
conditions will prevail.
&&
.MARINE...14/200 pM.
Northwest winds will continue to create small craft advisory
conditions from Piedras Blancas to San Nicolas island including
the west portion of the Santa Barbara basin through Monday night.
The strongest winds will likely occur in the vicinity of the
Northern Channel islands this afternoon. The Northwest winds will
increase to possible gale force from Piedras Blancas to San
Nicolas island Sunday afternoon and prevail through Monday
morning. Northwest winds are expected to increase Thursday from
Piedras Blancas to San Nicolas island and sca conditions are
likely.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect until 3 AM PDT Sunday For zones
39-52. (See LAXNPWLOX).
Wind Advisory in effect until 9 PM PDT Sunday For zone 59. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 PM PDT Sunday For
zones 645-670-673-676. (See LAXMWWLOX).
Gale Warning in effect from 3 PM Sunday to 4 AM PDT Monday
For zones 645-670-673-676. (See LAXMWWLOX).
Small Craft Advisory in effect until 3 AM PDT Sunday For zone
650. (See LAXMWWLOX).
&&
$$
PUBLIC...Rorke
AVIATION...KJ
MARINE...Rorke
SYNOPSIS...Munroe
weather.gov/losangeles
[top]
Area Forecast Discussion
National Weather Service Sacramento CA
1017 PM PDT SAT MAY 14 2016
.Synopsis...
Cool down with a few showers or thunderstorms north of I-80 this
weekend. Then a warmup to lower 90s again by mid week followed by
another cool down and potential showers late in the week.
&&
.Discussion (Sunday through Tuesday)...
Upper low/trough tracking into/across ORE will be east of the CWA
on Sunday. Northerly winds begin to dry the boundary layer out a
bit on Sunday with stronger drying winds Monday into Tuesday.
Both Sun nite/Mon morning and Mon nite/Tue morning look to be
ideal set-ups for the formation of a modest northerly barrier jet
on the west side of the Sac Valley. Max temps mostly in the 80s
in the Valley on Mon or up to 5 degrees above normal will warm
into the low 90s in the Valley on Tue or 7-12 degrees above
normal. JClapp
&&
.EXTENDED DISCUSSION (Wednesday THROUGH Saturday)
The extended forecast models depict an upper level shortwave
ridge of high pressure over the western portion of the CONUS
Wednesday and Wednesday night, which will bring warm and dry
conditions across NorCal. High temperatures in the valley will be
about 10 degrees above normal Wednesday afternoon.
The stable air over the region on Wednesday will shift southeastward
as another trough of low pressure slides southward from the Pacific
Northwest. Model forecasts are in good agreement to the strength
and positioning of the system to move into NorCal sometime
Thursday afternoon or evening. The disturbance will bring cooler
temperatures and the possibility for showers and thunderstorms
through the end of the workweek. High temperatures in the valley
will drop to near or slightly below normal temperatures in the low
to mid 70s.
&&
.AVIATION...
Mainly VFR conditions the next 24 hours. Isolated showers will
diminish tonight over the Sierra, but are likely to redevelop
Sunday afternoon. South to west winds up to 10 kt will become
northwest on Sunday.
Dang
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
[top]
Area Forecast Discussion
National Weather Service Phoenix AZ
935 PM MST SAT MAY 14 2016
.SYNOPSIS...
Cooler air is beginning to move into the region as a low pressure
system in the northwest U.S. begins to deepen. Breezy conditions are
expected again for Sunday. Another Pacific weather system is
forecast to move into the southwestern states late Sunday through
Tuesday. This will provide even cooler temperatures along with slight
chances of thunderstorms mainly over northern and central Arizona.
Clearing skies with rebounding afternoon temperatures are forecast
for late next week.
&&
.DISCUSSION...
Clearing skies can be seen across southeastern California and the
western half of Arizona this evening. Earlier, a few thunderstorms
swept over the southeastern third of Arizona but that activity has
dissipated and pushed to the east. Low pressure system now over
Oregon continues to gradually deepen and spread its influence further
to the south. Models indicate this system will eventually drop down
towards the south, ultimately moving into northwest Arizona by
Tuesday evening. This will bring a slight chance for thunderstorms to
the region and keep relatively cooler air in place for a few days.
Rain chances are still on the low side but at least there`s a chance
for unsettled weather, particularly Tuesday afternoon through
Wednesday morning. Temperatures should start to climb back above
normals the rest of the week.
&&
.PREVIOUS DISCUSSION...
Latest satellite imagery shows several areas of cumulus congestus,
mainly concentrated across the Mogollon Rim, the CO Plateau and
portions of southeastern AZ. Isolated showers and thunderstorms have
developed, but are mainly relegated to the higher terrain near
Tucson and Flagstaff. Meanwhile, moisture values are running well
above average with dewpoints in the mid 40s. NAEFS PWAT percentiles
are also running above the 90th percentile, though ground based GPS-
IPW and TPW suggest PWATS are somewhat lower. The relatively moist
conditions have also kept temperatures at bay, which have generally
been running in the mid to upper 90s in the lower deserts. At Sky
Harbor Airport, the high has reached 100 degrees.
Preponderance of hi-res CAMs including the operational and
experimental HRRR continue to indicate that isolated convection will develop
across Gila County this afternoon and this evening. PoPs were increased
to around 10 percent in these areas, though in reality most precipitation
that falls will likely evaporate and not measure at the surface. Models
are in excellent agreement that much drier air will be transported
northeastward this evening and overnight, with the GEFS ensemble
mean indicating PWATS dropping as low as 0.40 inches. Consequently,
showers and thunderstorms will dissipate shortly after sunset.
&&
.AVIATION...
South-Central Arizona including KPHX...KIWA and KSDL...
Southeast California/Southwest Arizona including KIPL and KBLH...
A weak weather disturbance will continue to produce scattered
cumulus and altocumulus with broken-overcast cirrus this afternoon
before thinning out this evening. Over northern and southeastern
Arizona there will be isolated thunderstorms with some additional
weaker showers which will begin dissipating after sunset. Surface
winds will favor south and southwest directions through the evening
(gusts of 15-20 kts Phoenix area; 20-30 kts SE CA and SW AZ). Winds
will be stronger Sunday afternoon but with significantly less
cloudiness.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday...
A low pressure system will be centered over northwest Arizona on
Tuesday and Wednesday leading to a slight chance of thunderstorms
over south-central Arizona. Temperatures will be below normal with
light winds. The low exits Thursday before another system approaches
Friday and Saturday leading to breezy to windy conditions.
Temperatures will start off below normal Tuesday and Wednesday before
climbing back to normal by Friday. Humidities begin declining
Wednesday with Minimum values dipping to about 10% late in the week.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...Waters/Hirsch
PREVIOUS DISCUSSION...Kuhlman
AVIATION...AJ
FIRE WEATHER...AJ
Area Forecast Discussion
National Weather Service Phoenix AZ
454 AM MST SUN MAY 15 2016
.UPDATE...To AVIATION and FIRE WEATHER Discussions...
&&
.SYNOPSIS...
Cooler air is beginning to move into the region as a Pacific low
pressure system in the northwest U.S. begins to deepen and sag
further south. Breezy conditions are expected today with highs near
normals. This Pacific low is forecast to move into the southwestern
states tonight persisting through Tuesday. This will provide even
cooler temperatures along with slight chances of showers and
thunderstorms. Clearing skies with rebounding temperatures are
forecast for late in the week.
&&
.DISCUSSION...
Drier air has filtered into Arizona as westerly flow aloft moved in
around the southern fringe of the upper low currently situated across
the Pacific Northwest. This drier air has ended any shower or
thunderstorm chances with mainly clear skies expected today. Lowering
heights aloft will allow for some modest cooling to take place today
and as a result highs should only top out in the lower 90s across the
deserts. A deepening surface low over the Great Basin is increasing
pressure gradients across the Desert Southwest resulting in some
breezy winds currently across southeast California. The gradient
will strengthen later today with breezy to windy southwesterly winds
across the majority of the CWA. Winds will remain below advisory
levels, but some gusts to 35 mph are likely across southeast
California and southern Gila County. Elevated fire danger conditions
for a brief time may be realized across southern Gila County this
afternoon, but not enough to warrant any headlines.
The upper low eventually will start to dig southward through the
Great Basin on Monday into the Desert Southwest on Tuesday. Models
have been consistent with the overall track of this system, but have
shifted it further west slightly over the past 24 hours. Some
moisture advection is expected over our area Tuesday into early
Wednesday with PWATS increasing to between 0.50-0.75 inches. Though
this system is not very cold aloft (500mb temps near -16C) there
should be sufficient moisture and instability for some isolated
showers and thunderstorms starting Tuesday afternoon. Overall timing
has shifted a bit later, so rain chances will linger into Wednesday,
especially from Phoenix eastward. Have added in slight chance POPs
across south-central Arizona for Tuesday night and Wednesday morning
with chances remaining through Wednesday evening across the higher
terrain east of Phoenix. We could see a shot at some gusty thunderstorm
winds with an inverted V forecast sounding structure, but winds aloft
will be light, so would only rely on evaporative cooling effects.
Temperatures through Wednesday are forecast to be at or below normals
with Monday and Tuesday being the coolest days with highs mostly in
the upper 80s across the lower deserts. We will start to see some
warming across our western zones on Wednesday under rising heights
aloft as highs climb back into the middle 90s.
Model consensus continues to show a deep Pacific low digging
southward into the Pacific Northwest late this week, but what happens
thereafter is less certain as model spread increases into next
weekend. For the Desert Southwest, heights aloft and temperatures
will certainly rise on Thursday and Friday resulting in highs at or
just above normals (middle to upper 90s). Have low confidence in the
forecast picture for next weekend as it is not clear if the Pacific
low will dig far enough south to affect the Desert Southwest.
&&
.AVIATION...
South-Central Arizona including KPHX...KIWA and KSDL...
Southeast California/Southwest Arizona including KIPL and KBLH...
Dry cool front will make its way across the region today increasing
winds while promoting less cloud cover. Typical AM wind headings will
transition through south to southwest during the day while increasing
in speed. Gusts in the upper teens to low twenty knot range will be
possible for the Phoenix area terminals and KBLH, while stronger
winds off the mountains are expected for KIPL with gusts at or
greater than 30kts. West winds to linger later into the evening than
usual, losing their gustiness but remaining elevated. One final band
of mid-level clouds will continue to track E-SE with mostly clear
skies filling in behind the exiting SCT-BKN layers by the afternoon
and evening.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday...
A low pressure system will be centered over northwest Arizona on
Tuesday and Wednesday leading to a slight chance of thunderstorms
over south-central Arizona. Temperatures will be below normal with
mostly light winds. The upper low exits Thursday before another
system approaches Friday and Saturday leading to breezy to windy
conditions. Winds, under current forecast guidance, look to be
stronger for the late week system than the one responsible for the
winds over the late weekend and early in the work week. Temperatures
will start off below normal Tuesday and Wednesday before climbing
back to normal by Friday. Humidities begin declining Wednesday with
minimum values dipping to about 10% late in the week.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...Kuhlman
AVIATION...Nolte
FIRE WEATHER...Nolte/AJ
Area Forecast Discussion
National Weather Service Phoenix AZ
935 PM MST SAT MAY 14 2016
.SYNOPSIS...
Cooler air is beginning to move into the region as a low pressure
system in the northwest U.S. begins to deepen. Breezy conditions are
expected again for Sunday. Another Pacific weather system is
forecast to move into the southwestern states late Sunday through
Tuesday. This will provide even cooler temperatures along with slight
chances of thunderstorms mainly over northern and central Arizona.
Clearing skies with rebounding afternoon temperatures are forecast
for late next week.
&&
.DISCUSSION...
Clearing skies can be seen across southeastern California and the
western half of Arizona this evening. Earlier, a few thunderstorms
swept over the southeastern third of Arizona but that activity has
dissipated and pushed to the east. Low pressure system now over
Oregon continues to gradually deepen and spread its influence further
to the south. Models indicate this system will eventually drop down
towards the south, ultimately moving into northwest Arizona by
Tuesday evening. This will bring a slight chance for thunderstorms to
the region and keep relatively cooler air in place for a few days.
Rain chances are still on the low side but at least there`s a chance
for unsettled weather, particularly Tuesday afternoon through
Wednesday morning. Temperatures should start to climb back above
normals the rest of the week.
&&
.PREVIOUS DISCUSSION...
Latest satellite imagery shows several areas of cumulus congestus,
mainly concentrated across the Mogollon Rim, the CO Plateau and
portions of southeastern AZ. Isolated showers and thunderstorms have
developed, but are mainly relegated to the higher terrain near
Tucson and Flagstaff. Meanwhile, moisture values are running well
above average with dewpoints in the mid 40s. NAEFS PWAT percentiles
are also running above the 90th percentile, though ground based GPS-
IPW and TPW suggest PWATS are somewhat lower. The relatively moist
conditions have also kept temperatures at bay, which have generally
been running in the mid to upper 90s in the lower deserts. At Sky
Harbor Airport, the high has reached 100 degrees.
Preponderance of hi-res CAMs including the operational and
experimental HRRR continue to indicate that isolated convection will develop
across Gila County this afternoon and this evening. PoPs were increased
to around 10 percent in these areas, though in reality most precipitation
that falls will likely evaporate and not measure at the surface. Models
are in excellent agreement that much drier air will be transported
northeastward this evening and overnight, with the GEFS ensemble
mean indicating PWATS dropping as low as 0.40 inches. Consequently,
showers and thunderstorms will dissipate shortly after sunset.
&&
.AVIATION...
South-Central Arizona including KPHX...KIWA and KSDL...
Southeast California/Southwest Arizona including KIPL and KBLH...
A weak weather disturbance will continue to produce scattered
cumulus and altocumulus with broken-overcast cirrus this afternoon
before thinning out this evening. Over northern and southeastern
Arizona there will be isolated thunderstorms with some additional
weaker showers which will begin dissipating after sunset. Surface
winds will favor south and southwest directions through the evening
(gusts of 15-20 kts Phoenix area; 20-30 kts SE CA and SW AZ). Winds
will be stronger Sunday afternoon but with significantly less
cloudiness.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday...
A low pressure system will be centered over northwest Arizona on
Tuesday and Wednesday leading to a slight chance of thunderstorms
over south-central Arizona. Temperatures will be below normal with
light winds. The low exits Thursday before another system approaches
Friday and Saturday leading to breezy to windy conditions.
Temperatures will start off below normal Tuesday and Wednesday before
climbing back to normal by Friday. Humidities begin declining
Wednesday with Minimum values dipping to about 10% late in the week.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...Waters/Hirsch
PREVIOUS DISCUSSION...Kuhlman
AVIATION...AJ
FIRE WEATHER...AJ
Area Forecast Discussion
National Weather Service Phoenix AZ
221 PM MST SUN MAY 15 2016
.SYNOPSIS... Cooler air is beginning to move into the region as a
Pacific low pressure system in the northwest U.S. begins to deepen
and sag further south. The Pacific low is forecast to move into the
southwestern states early this week persisting through Wednesday.
This will provide even cooler temperatures along with slight chances
of showers and thunderstorms Tuesday. Clearing skies with rebounding
temperatures are forecast for late in the week.
&&
.DISCUSSION...
Upper low across the Great Basin continues to drift eastward this
afternoon. Latest satellite imagery shows widespread cloudiness out
ahead of this system across the Rockies with a smattering of showers
and thunderstorms extending southward into Chihuahua. Across the
desert southwest, skies have been mostly clear with temperatures in
the lower 90s across the lower deserts, a drop of roughly 6 to 8 from
those observed yesterday. Dewpoints are also significantly lower east
of Phoenix, though moisture is already increasing again across
western Arizona ahead of a vort max traversing the Mojave Desert.
This vort max will also strengthen wind fields across the region and
breezy conditions are anticipated through this evening across much of
the area.
No major changes were made to the forecast in the short-term.
Temperatures tonight will be near or slightly above average with
subsiding winds and mostly clear skies.
&&
.PREVIOUS DISCUSSION...
The upper low eventually will start to dig southward through the
Great Basin on Monday into the Desert Southwest on Tuesday. Models
have been consistent with the overall track of this system, but have
shifted it further west slightly over the past 24 hours. Some
moisture advection is expected over our area Tuesday into early
Wednesday with PWATS increasing to between 0.50-0.75 inches. Though
this system is not very cold aloft (500mb temps near -16C) there
should be sufficient moisture and instability for some isolated
showers and thunderstorms starting Tuesday afternoon. Overall timing
has shifted a bit later, so rain chances will linger into Wednesday,
especially from Phoenix eastward. Have added in slight chance POPs
across south-central Arizona for Tuesday night and Wednesday morning
with chances remaining through Wednesday evening across the higher
terrain east of Phoenix. We could see a shot at some gusty thunderstorm
winds with an inverted V forecast sounding structure, but winds aloft
will be light, so would only rely on evaporative cooling effects.
Temperatures through Wednesday are forecast to be at or below normals
with Monday and Tuesday being the coolest days with highs mostly in
the upper 80s across the lower deserts. We will start to see some
warming across our western zones on Wednesday under rising heights
aloft as highs climb back into the middle 90s.
Model consensus continues to show a deep Pacific low digging
southward into the Pacific Northwest late this week, but what happens
thereafter is less certain as model spread increases into next
weekend. For the Desert Southwest, heights aloft and temperatures
will certainly rise on Thursday and Friday resulting in highs at or
just above normals (middle to upper 90s). Have low confidence in the
forecast picture for next weekend as it is not clear if the Pacific
low will dig far enough south to affect the Desert Southwest.
&&
.AVIATION...
South-Central Arizona including KPHX...KIWA and KSDL...
Southeast California/Southwest Arizona including KIPL and KBLH...
Dry cool front will make its way across the region today increasing
winds while promoting less cloud cover. Typical AM wind headings will
transition through south to southwest during the day while increasing
in speed. Gusts in the upper teens to low twenty knot range will be
possible for the Phoenix area terminals and KBLH, while stronger
winds off the mountains are expected for KIPL with gusts at or
greater than 30kts. West winds to linger later into the evening than
usual, losing their gustiness but remaining elevated. One final band
of mid-level clouds will continue to track E-SE with mostly clear
skies filling in behind the exiting SCT-BKN layers by the afternoon
and evening.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday...
A low pressure system will be centered over northwest Arizona on
Tuesday and Wednesday leading to a slight chance of thunderstorms
over south-central Arizona. Temperatures will be below normal with
mostly light winds. The upper low exits Thursday before another
system approaches Friday and Saturday leading to breezy to windy
conditions. Winds, under current forecast guidance, look to be
stronger for the late week system than the one responsible for the
winds over the late weekend and early in the work week. Temperatures
will start off below normal Tuesday and Wednesday before climbing
back to normal by Friday. Humidities begin declining Wednesday with
minimum values dipping to about 10% late in the week.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...Hirsch
PREVIOUS DISCUSSION...Kuhlman
AVIATION...Nolte
FIRE WEATHER...Nolte/AJ
Area Forecast Discussion
National Weather Service Phoenix AZ
454 AM MST SUN MAY 15 2016
.UPDATE...To AVIATION and FIRE WEATHER Discussions...
&&
.SYNOPSIS...
Cooler air is beginning to move into the region as a Pacific low
pressure system in the northwest U.S. begins to deepen and sag
further south. Breezy conditions are expected today with highs near
normals. This Pacific low is forecast to move into the southwestern
states tonight persisting through Tuesday. This will provide even
cooler temperatures along with slight chances of showers and
thunderstorms. Clearing skies with rebounding temperatures are
forecast for late in the week.
&&
.DISCUSSION...
Drier air has filtered into Arizona as westerly flow aloft moved in
around the southern fringe of the upper low currently situated across
the Pacific Northwest. This drier air has ended any shower or
thunderstorm chances with mainly clear skies expected today. Lowering
heights aloft will allow for some modest cooling to take place today
and as a result highs should only top out in the lower 90s across the
deserts. A deepening surface low over the Great Basin is increasing
pressure gradients across the Desert Southwest resulting in some
breezy winds currently across southeast California. The gradient
will strengthen later today with breezy to windy southwesterly winds
across the majority of the CWA. Winds will remain below advisory
levels, but some gusts to 35 mph are likely across southeast
California and southern Gila County. Elevated fire danger conditions
for a brief time may be realized across southern Gila County this
afternoon, but not enough to warrant any headlines.
The upper low eventually will start to dig southward through the
Great Basin on Monday into the Desert Southwest on Tuesday. Models
have been consistent with the overall track of this system, but have
shifted it further west slightly over the past 24 hours. Some
moisture advection is expected over our area Tuesday into early
Wednesday with PWATS increasing to between 0.50-0.75 inches. Though
this system is not very cold aloft (500mb temps near -16C) there
should be sufficient moisture and instability for some isolated
showers and thunderstorms starting Tuesday afternoon. Overall timing
has shifted a bit later, so rain chances will linger into Wednesday,
especially from Phoenix eastward. Have added in slight chance POPs
across south-central Arizona for Tuesday night and Wednesday morning
with chances remaining through Wednesday evening across the higher
terrain east of Phoenix. We could see a shot at some gusty thunderstorm
winds with an inverted V forecast sounding structure, but winds aloft
will be light, so would only rely on evaporative cooling effects.
Temperatures through Wednesday are forecast to be at or below normals
with Monday and Tuesday being the coolest days with highs mostly in
the upper 80s across the lower deserts. We will start to see some
warming across our western zones on Wednesday under rising heights
aloft as highs climb back into the middle 90s.
Model consensus continues to show a deep Pacific low digging
southward into the Pacific Northwest late this week, but what happens
thereafter is less certain as model spread increases into next
weekend. For the Desert Southwest, heights aloft and temperatures
will certainly rise on Thursday and Friday resulting in highs at or
just above normals (middle to upper 90s). Have low confidence in the
forecast picture for next weekend as it is not clear if the Pacific
low will dig far enough south to affect the Desert Southwest.
&&
.AVIATION...
South-Central Arizona including KPHX...KIWA and KSDL...
Southeast California/Southwest Arizona including KIPL and KBLH...
Dry cool front will make its way across the region today increasing
winds while promoting less cloud cover. Typical AM wind headings will
transition through south to southwest during the day while increasing
in speed. Gusts in the upper teens to low twenty knot range will be
possible for the Phoenix area terminals and KBLH, while stronger
winds off the mountains are expected for KIPL with gusts at or
greater than 30kts. West winds to linger later into the evening than
usual, losing their gustiness but remaining elevated. One final band
of mid-level clouds will continue to track E-SE with mostly clear
skies filling in behind the exiting SCT-BKN layers by the afternoon
and evening.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday...
A low pressure system will be centered over northwest Arizona on
Tuesday and Wednesday leading to a slight chance of thunderstorms
over south-central Arizona. Temperatures will be below normal with
mostly light winds. The upper low exits Thursday before another
system approaches Friday and Saturday leading to breezy to windy
conditions. Winds, under current forecast guidance, look to be
stronger for the late week system than the one responsible for the
winds over the late weekend and early in the work week. Temperatures
will start off below normal Tuesday and Wednesday before climbing
back to normal by Friday. Humidities begin declining Wednesday with
minimum values dipping to about 10% late in the week.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...Kuhlman
AVIATION...Nolte
FIRE WEATHER...Nolte/AJ
Area Forecast Discussion
National Weather Service Phoenix AZ
935 PM MST SAT MAY 14 2016
.SYNOPSIS...
Cooler air is beginning to move into the region as a low pressure
system in the northwest U.S. begins to deepen. Breezy conditions are
expected again for Sunday. Another Pacific weather system is
forecast to move into the southwestern states late Sunday through
Tuesday. This will provide even cooler temperatures along with slight
chances of thunderstorms mainly over northern and central Arizona.
Clearing skies with rebounding afternoon temperatures are forecast
for late next week.
&&
.DISCUSSION...
Clearing skies can be seen across southeastern California and the
western half of Arizona this evening. Earlier, a few thunderstorms
swept over the southeastern third of Arizona but that activity has
dissipated and pushed to the east. Low pressure system now over
Oregon continues to gradually deepen and spread its influence further
to the south. Models indicate this system will eventually drop down
towards the south, ultimately moving into northwest Arizona by
Tuesday evening. This will bring a slight chance for thunderstorms to
the region and keep relatively cooler air in place for a few days.
Rain chances are still on the low side but at least there`s a chance
for unsettled weather, particularly Tuesday afternoon through
Wednesday morning. Temperatures should start to climb back above
normals the rest of the week.
&&
.PREVIOUS DISCUSSION...
Latest satellite imagery shows several areas of cumulus congestus,
mainly concentrated across the Mogollon Rim, the CO Plateau and
portions of southeastern AZ. Isolated showers and thunderstorms have
developed, but are mainly relegated to the higher terrain near
Tucson and Flagstaff. Meanwhile, moisture values are running well
above average with dewpoints in the mid 40s. NAEFS PWAT percentiles
are also running above the 90th percentile, though ground based GPS-
IPW and TPW suggest PWATS are somewhat lower. The relatively moist
conditions have also kept temperatures at bay, which have generally
been running in the mid to upper 90s in the lower deserts. At Sky
Harbor Airport, the high has reached 100 degrees.
Preponderance of hi-res CAMs including the operational and
experimental HRRR continue to indicate that isolated convection will develop
across Gila County this afternoon and this evening. PoPs were increased
to around 10 percent in these areas, though in reality most precipitation
that falls will likely evaporate and not measure at the surface. Models
are in excellent agreement that much drier air will be transported
northeastward this evening and overnight, with the GEFS ensemble
mean indicating PWATS dropping as low as 0.40 inches. Consequently,
showers and thunderstorms will dissipate shortly after sunset.
&&
.AVIATION...
South-Central Arizona including KPHX...KIWA and KSDL...
Southeast California/Southwest Arizona including KIPL and KBLH...
A weak weather disturbance will continue to produce scattered
cumulus and altocumulus with broken-overcast cirrus this afternoon
before thinning out this evening. Over northern and southeastern
Arizona there will be isolated thunderstorms with some additional
weaker showers which will begin dissipating after sunset. Surface
winds will favor south and southwest directions through the evening
(gusts of 15-20 kts Phoenix area; 20-30 kts SE CA and SW AZ). Winds
will be stronger Sunday afternoon but with significantly less
cloudiness.
Aviation discussion not updated for amended TAFs.
&&
.FIRE WEATHER...
Tuesday through Saturday...
A low pressure system will be centered over northwest Arizona on
Tuesday and Wednesday leading to a slight chance of thunderstorms
over south-central Arizona. Temperatures will be below normal with
light winds. The low exits Thursday before another system approaches
Friday and Saturday leading to breezy to windy conditions.
Temperatures will start off below normal Tuesday and Wednesday before
climbing back to normal by Friday. Humidities begin declining
Wednesday with Minimum values dipping to about 10% late in the week.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not expected.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
Visit us on Facebook...Twitter...and at weather.gov/phoenix
DISCUSSION...Waters/Hirsch
PREVIOUS DISCUSSION...Kuhlman
AVIATION...AJ
FIRE WEATHER...AJ