Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/14/16
Area Forecast Discussion
National Weather Service Flagstaff AZ
345 PM MST FRI MAY 13 2016
.SYNOPSIS...A Low pressure system off the west coast will bring
increasing southwest winds, cooling temperatures, and slight chances
for showers and thunderstorms this weekend. From Monday through
Thursday, the low pressure system will cross the state causing
better chances for showers and thunderstorms and near to slightly
below average temperatures.
&&
.DISCUSSION...High pressure over Arizona peaked today and will start
to move east tonight as a low pressure system approaches the West
Coast. Increasing mid and high level moisture from the south brought
a few light showers to southern Apache County this afternoon.
On Saturday, the high pressure will continue to move east as the low
off the West Coast moves eastward. This will bring a cooling trend,
increasing southwest winds, and increasing moisture. Isolated high
based showers and thunderstorms will be possible over higher terrain
-primarily along and north of the Mogollon Rim on Saturday. By
Sunday, the approaching low pressure system will bring strong
southwest winds across much of northern Arizona. The strongest winds
are expected across central and southern Navajo and Apache counties,
where wind gusts exceeding 40 mph are possible.
From Monday through Thursday: The upper level low will move
southward on Monday before crossing Arizona on Tuesday and
Wednesday. This will lead to increasing chances for precipitation
and near to slightly below average daytime temperatures. On Monday,
there are slight chances for showers and thunderstorms, primarily
along and north of Interstate 40. On Tuesday and Wednesday, better
chances for showers are expected across all of northern Arizona as
the low passes over the state. By Thursday, the low is expected move
eastward into New Mexico with lingering showers and thunderstorms
along the Arizona and New Mexico border.
&&
.AVIATION...For the 00Z package...Expect SKC-SCT skies through 18Z
Saturday, though east of KSOW may be the exception with a slight
chance of showers tonight. Slight chance for showers spread to much
of northern Arizona after 18Z Saturday. Light winds overnight will
turn southwesterly and breezy after 18Z Saturday as well. Aviation
discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Southwest winds will increase on Saturday as a
trough builds into the southwest United States, along with the
threat of isolated high-based afternoon thunderstorms. Generally dry
conditions are forecast for Sunday, though southwest winds will
strengthen that day leading to near critical fire weather
conditions.
Monday through Wednesday...Increasing chances of afternoon
thunderstorms along with cooler daytime temperatures are expected as
low pressure settles into the region.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...MAS
AVIATION...KD
FIRE WEATHER...KD
For Northern Arizona weather information visit
weather.gov/flagstaff
[top]
Area Forecast Discussion
National Weather Service Phoenix AZ
327 PM MST FRI MAY 13 2016
.UPDATE...
Updated Aviation and Fire Weather sections.
&&
.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...
Return flow around a ridge to our east predominates this afternoon,
which has helped to produce well-above normal temperatures but short
of records. Meanwhile, moisture continues to lift northward out of
Sonora ahead an anomalous trough evident in the upper-level
streamlines across the Gulf of California. Little impact from this
system is expected today or tonight. However, global models and CAMs
continue to suggest that the residual moisture will promote the
development of isolated convection Saturday. PoPs were consequently
increased (but remain below 10 percent) for Saturday morning and
afternoon, particularly from Phoenix eastward and across the higher
terrain. The increase in low- level moisture (mixing ratios up to
around 6 g/kg) and cloudiness will have an effect on temperatures and
highs were lowered roughly one degree from the previous forecast.
Nevertheless, temperatures will remain several degrees above average.
&&
.PREVIOUS DISCUSSION...
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...
A couple of weak weather disturbance ahead of an approaching low
pressure system will create some cloudiness above FL100 with possibly
some isolated virga the rest of the afternoon into Saturday. Areas
east of the Lower Colorado River Valley are most likely to be
affected (more so southeast AZ). Otherwise, expect familiar warm
season diurnal wind patterns (stronger tomorrow afternoon).
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
Monday through Friday...
A low pressure system centered over Idaho on Monday will dig
southward becoming centered over northwest AZ by Tuesday afternoon.
This will lead to a slight chance of thunderstorms Tuesday/Tuesday
night. The low will weaken Wednesday and move out Thursday. Breezy to
windy conditions develop Friday (mainly near and west of the Lower
Colorado River Valley) as another system approaches. Minimum
humidities will generally be in the 10-15 percent range on the lower
deserts (closer to 15% on Tuesday; closer 10% Thu-Fri). Overnight
recovery will be good early in the week then slowly decline.
&&
.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
[top]
Area Forecast Discussion
National Weather Service Tucson AZ
245 PM MST FRI MAY 13 2016
.SYNOPSIS...
Strong high pressure aloft will bring well above average
temperatures Saturday. There is also enough moisture for a slight
chance of showers and thunderstorms from Tucson eastward Saturday
afternoon. A storm system moving north of the area will then bring
gusty winds Sunday followed by cooler temperatures early next week.
&&
.DISCUSSION...Partly cloudy to mostly cloudy skies across southeast
Arizona this afternoon as fairly thick cirriform clouds move
northeastward across the area. Some cumuloform clouds were also
noted across the White mountains and near the New Mexico border as
per visible satellite imagery. Have maintained a slight chance of
showers and thunderstorms thru this evening mainly near the
International border south-to-southeast of Tucson, and across far
eastern sections. Dry conditions are then expected late tonight into
Saturday morning.
Southwesterly flow aloft will prevail Saturday afternoon ahead of a
low pressure system moving eastward into the Pacific NW. 13/12Z Univ
of AZ WRF-NAM and WRF-GFS were quite similar with developing
showers/thunderstorms mainly near the Catalina/Rincon mountains near
Tucson early Saturday afternoon. These showers/thunderstorms are
then depicted to expand in coverage while moving newd across ern
sections Saturday afternoon and early Saturday evening. These
solutions are more similar to the 13/12Z ECMWF versus the drier GFS.
Thus, the official forecast depicts a slight chance of showers/tstms
from near the Tucson metro area eastward to the New Mexico border
Saturday afternoon/evening. Dry conditions are then expected
Saturday night-Monday night. However, a tight mid-level gradient
will translate into gusty southwest winds Sunday afternoon. Wind
advisory criteria may be achieved Sunday afternoon for locales
southeast of Tucson. Somewhat less wind will occur Monday.
GFS/ECMWF were similar with deepening an upper trough over the Great
Basin/Intermountain west/southwestern CONUS Tue-Wed. The ECMWF was
markedly more robust with liquid amounts versus the GFS. At any
rate, There is a chance of showers/tstms Tue afternoon/evening
mainly across the White mountains. Have included a slight chance of
showers/tstms for eastern sections Wednesday. A drying trend should
commence Wed night as the mid-level trough axis moves east of the
area. Still enough moisture for a slight chance of showers/tstms
across the White mountains Wed night-Thur. Dry conditions are then
expected to prevail Thur night-Fri under wly/swly flow aloft.
High temps Sat will be quite similar to temps achieved this
afternoon followed by about 5 degs or so of daily cooling Sun-Mon.
High temps Tue-Wed will be below normal, then a pronounced warming
trend is on tap Thur-Fri.
&&
.AVIATION...VALID THRU 15/00Z.
Expect isolated -TSRA/-SHRA near the Mexico and New Mexico border
thru 14/04Z otherwise sct-bkn clouds above 20k ft thru much of
tonight. After 14/19Z isold-sct -TSRA/-SHRA developing with sct to
locally bkn 10k ft clouds. Surface wind through 14/03Z will be
wly/nwly at 10-15 kts then becoming variable at less than 10 kts.
Wind becoming SW 9-16 kts Saturday afternoon. Aviation discussion
not updated for TAF ammendments.
&&
.FIRE WEATHER...Any convection that develops through this evening
should remain limited to the Mexico and New Mexico border. However
moisture will increase later tonight and Saturday enough to bring a
threat of showers and thunderstorms from the Tucson area eastward
Saturday afternoon and early evening. Any storms that develop
Saturday will move to the east-northeast.
A strong upper level trough will approach the region Sunday forcing
drier air over the area on gusty southwest winds. At this time it
looks like a significant portion of fire zones 151 and 152 will
reach critical fire weather conditions Sunday afternoon.
Therefore I have issued a Fire Weather Watch for the southern 2/3rds
of both zones for late Sunday morning into early Sunday evening.
Dry but cooler conditions will prevail Monday followed by a slight
chance of showers and thunderstorms Tuesday into Wednesday, mainly
north. Thursday and Friday will be warm and dry with less wind.
&&
.TWC Watches/Warnings/Advisories...
Fire Weather Watch from Sunday morning through Sunday evening
for AZZ151-152.
&&
$$
Discussion...Francis
Aviation/Fire Weather...Cerniglia
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Phoenix AZ
221 PM 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...
Return flow around a ridge to our east predominates this afternoon,
which has helped to produce well-above normal temperatures but short
of records. Meanwhile, moisture continues to lift northward out of
Sonora ahead an anomalous trough evident in the upper-level
streamlines across the Gulf of California. Little impact from this
system is expected today or tonight. However, global models and CAMs
continue to suggest that the residual moisture will promote the
development of isolated convection Saturday. PoPs were consequently
increased (but remain below 10 percent) for Saturday morning and
afternoon, particularly from Phoenix eastward and across the higher
terrain. The increase in low- level moisture (mixing ratios up to
around 6 g/kg) and cloudiness will have an effect on temperatures and
highs were lowered roughly one degree from the previous forecast.
Nevertheless, temperatures will remain several degrees above average.
&&
.PREVIOUS DISCUSSION...
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 Flagstaff AZ
945 AM MST FRI MAY 13 2016
.SYNOPSIS...High pressure over northern Arizona will lead to another
warm day, with high temperatures around 10 degrees above average.
Limited moisture will bring a slight chance of thunderstorms to the
White Mountains this afternoon. An approaching low pressure system
will cause increasing southwest winds, cooling temperatures, and
slight chances for showers and thunderstorms over higher terrain
over the weekend. From Monday through Thursday, the low pressure
system will cross the state causing better chances for showers and
thunderstorms and near to slight below normal temperatures.
&&
.DISCUSSION...Increasing mid and high level moisture from the south
today will bring a slight chance of high based showers and
thunderstorms to the White Mountains today. The leading edge of this
moisture is seen in the form of high clouds moving into southern
Arizona this morning. Will update the forecast for Northern Gila,
Eastern Mogollon Rim, and White Mountains today and this evening.
&&
.PREV DISCUSSION /425 AM MST/...For today: A ridge of high pressure
in place across northern Arizona will lead to the warmest
temperatures of the year so far. In general, high temperatures are
forecast to be around 10 degrees above normal. In addition, expect
mostly clear skies, dry weather and relatively light winds. An
exception to this may be in the White Mountains region where a
slight chance for high based showers and thunderstorms is forecast.
For the weekend: While Saturday is expected to be another warm
day, the upper level ridge axis shifts eastward with the approach
of a Pacific low pressure system. This will result in the
beginning of a slow cooling trend and increasing southwest winds.
In addition, enough low and mid level moisture may be drawn
northward into the region for isolated high based showers and
thunderstorms over higher terrain - primarily along and north of
the Mogollon Rim. By Sunday, the approaching low pressure system
is forecast to cause strong southwest winds across much of
northern Arizona. The strongest winds are expected across central
and southern Navajo and Apache counties, where wind gusts
exceeding 40 mph are possible.
From Monday through Thursday: The upper level low is forecast to
dive southward on Monday before crossing Arizona on Tuesday and
Wednesday. This will lead to increasing chances for precipitation
and near to slightly below normal daytime temperatures. On
Monday, slight chances for showers and thunderstorms are forecast,
primarily along and north of Interstate 40. On Tuesday and
Wednesday, better chances for showers are forecast across all of
northern Arizona as the low passes over the state. By Thursday,
The low is forecast to move eastward into New Mexico with
lingering showers and thunderstorms possible along the Arizona and
New Mexico border.
&&
.AVIATION...For the 18Z package...Expect VFR conditions
for the next 24 hours with occasional southwesterly breezes this
afternoon. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...A high pressure ridge will remain over the
area today with above normal high temperatures...followed by an
approaching low pressure trough on Saturday. Southwest winds will
increase on Saturday, along with the threat of isolated high based
afternoon thunderstorms.
Sunday through Tuesday...Low min Rh`s on Sunday and very windy
afternoon conditions will lead to near critical fire weather
conditions. Monday and Tuesday, increasing chances of afternoon
thunderstorms are expected as low pressure moves on by.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...MAS/RR
AVIATION...KD
FIRE WEATHER...TC
For Northern Arizona weather information visit
weather.gov/flagstaff
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 San Diego CA
851 AM PDT THU MAY 12 2016
.SYNOPSIS...
Warmer today with low clouds likely clearing out of inland areas
by early afternoon and some clouds possibly sticking to the
beaches for most of the day. A deepening marine layer and slow
cooling trend will develop Friday through Sunday as a trough moves
by to the north. Night and morning low clouds will reach far
inland this weekend, and drizzle may be possible Sunday night and
Monday morning west of the mountains. The trough will also create
gusty westerly winds over the mountains and deserts Late Saturday
through Sunday night. A slow warming trend will develop Monday
through Thursday as high pressure aloft strengthens.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
Morning visible satellite imagery shows overcast marine layer
stratus about 15-25 miles inland this morning, which is not as far
inland as it was yesterday morning. Looking at the 12Z Miramar
sounding, there is a 10 degree inversion at around 1800 feet
about MSL, and observations indicate a cloud thickness of around
900-1000 feet. The strong inversion and decent cloud thickness
should result in slow clearing today, with clouds clearing out of
inland areas by late morning/early afternoon, and a chance that
low clouds could stick to the beaches through late in the day.
Meanwhile, water vapor satellite shows a low pressure system
spinning over the northeast Pacific, with an upper level ridge
building over Southern California. Due to the ridge, conditions
across the region will continue to warm, with highs expected to
reach 3-7 degrees above normal, and locally 10 degrees above
normal. The lower deserts could reach 100 degrees in some
locations. With the ridge peaking in strength tonight, the marine
layer may get a few hundred feet more shallow, with stratus once
again moving inland about 15-25 miles tonight through Friday
morning.
The ridge will start to weaken on Friday as the aforementioned low
approaches the west coast. This will create the beginning of a
cooling trend and also deepening marine layer trend as the low
moves inland through the Pacific Northwest this weekend. The
marine layer may get deep and thick enough to create some patchy
drizzle Sunday night/Monday morning. Onshore pressure gradients
will strengthen as well, with San Diego to Las Vegas gradients
increasing to near 11-13 MB Saturday evening, and then up to 14 MB
late Sunday. Onshore flow this strong should be enough to create
strong and gusty west winds in the mountains and deserts Saturday
evening through Sunday night, with wind gusts of 50 MPH and
locally 60 MPH possible.
We then go into a warming trend again Monday through Thursday as
ridging gradually builds across the region, with a shallower
marine layer each day. The ECMWF is stronger with the ridge, and
thus warmer, than the GFS. The GFS actually shows a short-wave
trough moving across the Great Basin and down into Arizona Monday-
Tuesday which could bring less in the way of warming and less in
the way of a shallower marine layer.
&&
.AVIATION...
121600Z...Coast/Valleys...Stratus with bases 900-1200 ft MSL and
tops to 1600 ft MSL will gradually clear to near the coast by 19Z.
Local vis 2-4 mi will continue through 17Z within 15 mi of the
coast. Local BKN cigs will continue this afternoon along the
immediate coast. Stratus will begin to move back into the coastal
airports between 00-02Z and spread 15-20 mi inland tonight, with
bases around 900-1200 ft MSL and tops to 1600 ft MSL. Local vis will
be below 2 mi after 08Z in the valleys, including vcnty KRNM and
KAJO.
Mtns/Deserts...Clear with unrestricted visibility through tonight.
&&
.MARINE...
900 AM...No hazardous marine weather is expected through Monday.
&&
.SKYWARN...
Skywarn activation will not be needed today.
&&
.SGX Watches/Warnings/Advisories...
CA...None.
PZ...None.
&&
$$
PUBLIC...Harrison
AVIATION/MARINE...Maxwell
Area Forecast Discussion
National Weather Service Phoenix AZ
730 AM MST THU MAY 12 2016
.SYNOPSIS...
A high pressure system will build into the region for a significant
warming trend through the end of the work week. Many lower desert
locations will warm into the 100 to 104 degree range Thursday
through Saturday. Another Pacific weather system is forecast to move
into the western states, mainly north of Arizona, late Sunday and
early next week. Although this system will be mostly dry for
southern Arizona, it will result in breezy afternoons along with
cooler temperatures.
&&
.DISCUSSION...
The region is now caught in the doldrums of high pressure, light
wind, and unseasonably warm afternoon temperatures through Saturday.
As the previous discussion below highlights, some temperature relief
will come Sunday and early next week as a new Pacific low pressure
system is forecast to settle over the region for a few days. Details
below. Current dry and warm forecasts through Saturday look good. No
updates necessary.
.PREVIOUS DISCUSSION...501 AM MST...
Early this morning, IR satellite imagery showed a batch of thin
cirrus clouds moving across the southern deserts, embedded in a
westerly flow aloft. Latest plot data showed 500mb heights up to
585DM across southern Arizona and heights were up 30-40m statewide,
indicating that upper ridging was continuing to build into the
desert southwest. Latest short and medium range model guidance, in
addition to GEFS ensemble guidance, continued to advertise a sharp
warming trend to persist through the end of the work week as high
pressure aloft strengthens and puts its stamp on our weather. By this
evening 500mb heights should reach to near 588dm over the lower
deserts and triple digits will become widespread over the lower
elevations. Peak heating should occur on Friday with the warmest
lower deserts climbing to around 105 degrees, and the forecast for
Phoenix will be 104 on that day. Overall there has been little change
in the forecast thinking by any of the models and there will be very
little change made to the forecast, especially for the rest of this
week. Confidence remains very high regarding the warming trend
through Friday.
Over the weekend, the GFS and ECMWF operational runs as well as GEFS
spaghetti ensemble members all advertise the start of a cooling
trend over the area as an area of low pressure along the Pacific
Northwest coast moves inland and then develops towards the southeast,
causing the upper ridge over Arizona to weaken and shift towards the
east. Heights aloft fall and we will see our high temperatures drop
into the middle 90s by the end of the weekend. Despite partly sunny
skies Saturday, highs will remain in the triple digits for the most
part and despite increasing sunshine Sunday we will see the cooling
continue with H5 heights dropping to 575dm or lower over the central
and western deserts.
For Monday into Tuesday, GFS and guidance becomes a bit more
divergent with the GFS a bit more bullish on bringing the upper low
further south and into central Arizona, eventually leading to a
slight chance of afternoon showers or thunderstorms across the higher
terrain of southern Gila County on Tuesday. ECMWF is a bit less
aggressive and drier for the lower deserts, but given the general
agreement between Gems ensemble members in bringing the low into
central Arizona, and with Naifs POPs guidance pushing at least a
slight chance of showers into the higher terrain northeast of
Phoenix, we decided to add the slight chance POPs into our forecast
for Tuesday. For the most part showers and storms during this period
will be confined to higher terrain areas of northern Arizona, which
is typical for upper lows this time of year. Temperatures of course
will fall some more, with cooler south central deserts dropping into
the mid to upper 80s Monday. Slight warming is expected Tuesday but
highs will stay below seasonal normals.
Drier west/northwest flow aloft spreads into the deserts from the
west Wednesday as the upper low moves off to the east, allowing for a
warming trend with high temperatures rising back into the mid 90s
and approaching seasonal normals.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL, Southeast
California/Southwest Arizona Including KIPL and KBLH
No aviation concerns expected. Strong high pressure will favor clear
skies with a few high clouds passing during the morning hours. Winds
will remain on the light side, mainly 8 kts or less and follow
normal diurnal trends.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
Saturday through Wednesday...
Strong high pressure will support above normal high temperatures in
the upper 90s to low 100s on Saturday. Next system moves through the
region on Sunday, with daytime highs in the low to mid 90s. On both
Saturday and Sunday, the combination of minimum relative humidity
values below 15 percent and breezy winds will elevate the fire
danger throughout the region, although conditions should remain
below critical thresholds. Monday through Wednesday, high
temperatures will be below normal with minimum humidities lifting
into the mid teens to near 20 percent range.
&&
.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...VASQUEZ/CB
Aviation...Hernandez
Fire Weather...Hernandez
Area Forecast Discussion
National Weather Service Phoenix AZ
730 AM MST THU MAY 12 2016
.SYNOPSIS...
A high pressure system will build into the region for a significant
warming trend through the end of the work week. Many lower desert
locations will warm into the 100 to 104 degree range Thursday
through Saturday. Another Pacific weather system is forecast to move
into the western states, mainly north of Arizona, late Sunday and
early next week. Although this system will be mostly dry for
southern Arizona, it will result in breezy afternoons along with
cooler temperatures.
&&
.DISCUSSION...
The region is now caught in the doldrums of high pressure, light
wind, and unseasonably warm afternoon temperatures through Saturday.
As the previous discussion below highlights, some temperature relief
will come Sunday and early next week as a new Pacific low pressure
system is forecast to settle over the region for a few days. Details
below. Current dry and warm forecasts through Saturday look good. No
updates necessary.
.PREVIOUS DISCUSSION...501 AM MST...
Early this morning, IR satellite imagery showed a batch of thin
cirrus clouds moving across the southern deserts, embedded in a
westerly flow aloft. Latest plot data showed 500mb heights up to
585DM across southern Arizona and heights were up 30-40m statewide,
indicating that upper ridging was continuing to build into the
desert southwest. Latest short and medium range model guidance, in
addition to GEFS ensemble guidance, continued to advertise a sharp
warming trend to persist through the end of the work week as high
pressure aloft strengthens and puts its stamp on our weather. By this
evening 500mb heights should reach to near 588dm over the lower
deserts and triple digits will become widespread over the lower
elevations. Peak heating should occur on Friday with the warmest
lower deserts climbing to around 105 degrees, and the forecast for
Phoenix will be 104 on that day. Overall there has been little change
in the forecast thinking by any of the models and there will be very
little change made to the forecast, especially for the rest of this
week. Confidence remains very high regarding the warming trend
through Friday.
Over the weekend, the GFS and ECMWF operational runs as well as GEFS
spaghetti ensemble members all advertise the start of a cooling
trend over the area as an area of low pressure along the Pacific
Northwest coast moves inland and then develops towards the southeast,
causing the upper ridge over Arizona to weaken and shift towards the
east. Heights aloft fall and we will see our high temperatures drop
into the middle 90s by the end of the weekend. Despite partly sunny
skies Saturday, highs will remain in the triple digits for the most
part and despite increasing sunshine Sunday we will see the cooling
continue with H5 heights dropping to 575dm or lower over the central
and western deserts.
For Monday into Tuesday, GFS and guidance becomes a bit more
divergent with the GFS a bit more bullish on bringing the upper low
further south and into central Arizona, eventually leading to a
slight chance of afternoon showers or thunderstorms across the higher
terrain of southern Gila County on Tuesday. ECMWF is a bit less
aggressive and drier for the lower deserts, but given the general
agreement between Gems ensemble members in bringing the low into
central Arizona, and with Naifs POPs guidance pushing at least a
slight chance of showers into the higher terrain northeast of
Phoenix, we decided to add the slight chance POPs into our forecast
for Tuesday. For the most part showers and storms during this period
will be confined to higher terrain areas of northern Arizona, which
is typical for upper lows this time of year. Temperatures of course
will fall some more, with cooler south central deserts dropping into
the mid to upper 80s Monday. Slight warming is expected Tuesday but
highs will stay below seasonal normals.
Drier west/northwest flow aloft spreads into the deserts from the
west Wednesday as the upper low moves off to the east, allowing for a
warming trend with high temperatures rising back into the mid 90s
and approaching seasonal normals.
&&
.AVIATION...
South-Central Arizona Including KPHX, KIWA, and KSDL, Southeast
California/Southwest Arizona Including KIPL and KBLH
No aviation concerns expected. Strong high pressure will favor clear
skies with a few high clouds passing during the morning hours. Winds
will remain on the light side, mainly 8 kts or less and follow
normal diurnal trends.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
Saturday through Wednesday...
Strong high pressure will support above normal high temperatures in
the upper 90s to low 100s on Saturday. Next system moves through the
region on Sunday, with daytime highs in the low to mid 90s. On both
Saturday and Sunday, the combination of minimum relative humidity
values below 15 percent and breezy winds will elevate the fire
danger throughout the region, although conditions should remain
below critical thresholds. Monday through Wednesday, high
temperatures will be below normal with minimum humidities lifting
into the mid teens to near 20 percent range.
&&
.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...VASQUEZ/CB
Aviation...Hernandez
Fire Weather...Hernandez
Area Forecast Discussion...corrected to add synopsis
National Weather Service Eureka CA
602 AM PDT THU MAY 12 2016
.SYNOPSIS...
An upper-level ridge will persist over northern California through
this evening. Patchy fog will persist through mid morning, mainly
near and west of highway 101. On Friday the ridge will shift to our
east a storm system approaches the region. Showers and isolated
thunderstorms may develop Friday afternoon and evening across
portions of Del Norte and Trinity counties. Rain will increase in
coverage Saturday morning and afternoon, as the system crosses the
area. Rain chances will diminish on Sunday, with a warming trend
expected next week.
.DISCUSSION...Low clouds and patchy fog/light drizzle have
expanded eastward from the coastal waters, roughly along and west
of the U.S. 101 corridor, and may continue to spread inland
somewhat over the next few hours. We added patchy fog with light
drizzle to the zones for these locations. By mid-morning, the fog
should being to burn off, with any residual fog being confined to
the immediate coastal areas. Otherwise, expect clouds to persist
today/tonight with near seasonal temperatures.
For Friday through next weekend, rain chances will increase for
Friday through the weekend. Not too much has changed in the latest
model runs, as they continue to portray an upper-level low passing
by to our north, with a respectable jet stream positioned across
northern California. As the system approached the coast Friday
evening, showers and isolated thunderstorms will develop during
the afternoon and evening. The best chance for thunderstorm
development continues to be across eastern portions of Del Norte
and Trinity counties. Taking a look at model soundings for this
area, they continue to show moderate instability, with NAM MUCAPEs
ranging from 500 to 2000 J/kg (highest across northern portions of
Trinity County). However...the GFS is less aggressive with these
values, showing about 500-1200 J/kg. In any event, both models
show good directional shear above 850mb which will aloft for good
tilting of the updraft (storm top ventilation), which combined
with 0-6km bulk shear values near 30 kts may result in a couple of
strong storms. Mid-level lapse rates today are lower than
yesterday (models now show less than 7 deg C/km), thus, severe
weather is not expected at this time.
As the system moves ashore Friday night/Saturday it will begin to
take on a negative tilt. Increasing ascent associated with this may
allow a few thunderstorms to develop despite decreasing instability.
Showers will also increase in coverage as the trough axis crosses
the state. Any precipitation will decrease in coverage on Sunday, as
the system departs the region. Upper-level ridging will start to
build across the region by early next week, with rising height
leading to warmer temperatures and decreased cloud cover. /PD
&&
.AVIATION...Marine layer is well established along the coastal forecast
area overnight. LIFR conditions were observed in both Crescent
City and Arcata airports. Cloud ceiling is steady at around 200
feet. Around 1 to 2 mile visibilities at Crescent City, and Arcata
saw visibilities as low as 1/4 mile at times. Being further
inland, Ukiah is seeing VFR conditions with mostly clear skies and
unrestricted visibilities. During the day, do expect gradually
improving conditions for Crescent City and Arcata, as the daytime
heating should erode the marine stratus somewhat. However, do
expect the marine stratus to strengthen overnight tonight as there
is not really any strong offshore wind component to cause the
marine layer to dissipate. /RL
&&
.MARINE...Light winds with low seas expected through Friday.
Seas, around 4 feet or so, are mixed with short, mid and long
period groups. Across Northern California and coastal waters,
there is not much pressure gradient. The weak pressure gradient is
expected to continue through Friday. On Saturday, a weak low
pressure will approach Northwest California coast, and this will
bring in southerly winds across the coastal waters. Northerly
winds will return to the area by Sunday, as the low moves inland
and a high builds into the East Pacific. Models are hinting that
northerly winds will increase to small craft level by Monday, with
gale force winds possible. Short period waves of 8 feet or higher
should return to the area early next week due to the increase in
northerly winds.
Visibilities are lowered this morning due to low clouds and light
drizzle from the marine layer covering the Northwest California
coast. The marine layer is expected to remain over the area
through tonight at the very least, since there is not really any
major atmospheric forcing that will lead to the dissipation of the
marine layer.
Forecast confidence is about average. Utilize RUC13 through
Thursday afternoon, then transition to Hi-Res ARW and Hi-Res NMM
through Thursday night. Uses a blend of ECMWF/GFS from Friday
through next week. /RL
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...NONE.
&&
$$
Visit us at http://WWW.WEATHER.GOV/EUREKA
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http://www.facebook.com/NWSEureka
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FOR FORECAST ZONE INFORMATION
SEE FORECAST ZONE MAP ONLINE:
http://www.weather.gov/eureka/zonemap.png
AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
432 AM PDT THU MAY 12 2016
.SYNOPSIS...
The overnight marine layer will persist through next week for
the coast and some valleys...otherwise mostly clear farther
inland. A high will be overhead by Thursday for above normal
temperatures that will drop by the weekend to around normal as a
low approaches. Then a high will arrive on Tuesday to raise temperatures
to above normal again.
&&
.SHORT TERM...(TDY-SAT)
Overall, 00Z models in good synoptic agreement through the period.
At upper levels, a ridge will peak in strength today then a trough
will develop over the area Friday/Saturday as an upper low moves
across the Pacific Northwest. Near the surface, weak onshore flow
today will gradually strengthen Friday/Saturday.
Forecast wise, main issue will continue to be the depth/inland
extent of the marine layer stratus. Current AMDAR soundings
indicate marine inversion based around 1400 feet while satellite
shows stratus covering/filling in across the coastal plain. Given
current inversion depth and surface gradients, some patchy stratus
will likely sneak into the lower coastal valleys today. By this
afternoon, stratus should dissipate all areas, allowing for a
sunny afternoon. For tonight through Saturday, the combination of
lowering H5 heights and increasing onshore flow will lead to a
deeper inversion and further inland extent for the marine layer
stratus.
As for temperatures, today will be the warmest day with most valley
locales climbing into the mid to upper 80s. For Friday/Saturday, a
cooling trend is anticipated due to upper level trough and more
marine layer influence.
As for winds, no significant issues are anticipated through the
period. Afternoon/evening winds across the mountains and deserts
will increase each day due to stronger onshore gradients, but will
remain below advisory levels.
.LONG TERM...(SUN-WED)
Overall, 00Z models continue to exhibit good synoptic agreement. At
upper levels, trough will remain over the area on Sunday then a ridge
will gradually develop off the coast Monday through Wednesday. Near
the surface, weak to moderate west to northwest flow will continue
through the period.
Forecast-wise, the marine layer stratus will continue to be the
main game in town. From Sunday through Wednesday, the depth and
inland extent of the marine layer will gradually diminish from day
to day. With this decreasing marine influence, temperatures will
be on the increase with Tuesday/Wednesday the warmest days. As for
winds, with the northwest tilt to the flow pattern, there will be
some gusty northwesterly winds during the evening and overnight
hours, but nothing that looks too problematic at this time.
&&
.AVIATION...12/1130Z...
At 1115Z...the marine inversion at KLAX was around 1500 ft deep.
The top of the inversion was around 3900 ft with a temperature of
21 deg C.
N of Point Conception...Moderate confidence in the 12z tafs.
Low clouds with LIFR/IFR cigs are expected to scour out +/- 1 hour
from 12z taf. 30 percent chance cigs could linger 2 hours past
scour out times. Overall, fairly confident cigs will scour around
the same time or an hour earlier due to more shallow marine layer.
Going with persistence.
S of Point Conception...High confidence with coastal 12z tafs.
mainly IFR but some coastal LIFR cigs possible through mid morning
hours. Moderate confidence for patchy ifr cigs across valley taf
sites. KBUR could see IFR cigs while KVNY should stay clear this
morning with vfr conds. 30 percent chance that KVNY gets ifr cigs
by 14z...and the same that KBUR will not receive cigs. Lower
confidence for ifr/lifr conds for KBUR/KVNY early Friday morning.
KLAX...Generally hi confidence in the 12z taf. Low clouds with
IFR cigs are expected to improve to IFR/MVFR 15Z-20Z. VFR
conditions will prevail aft 20Z til around 05Z this evening when
IFR cigs should move back into the airfield. 30% chance cigs
could develop a couple hours earlier or later than 05z.
KBUR...Generally low to moderate confidence in the 12z taf. Low
clouds with IFR cigs might not make it into KBUR this morning. 30%
chance cigs might not develop this morning. Otherwise, VFR
conditions are expected thru this afternoon through late tonight
or early Friday morning. The timing of the onset of low clouds
tonight may be off +/-a couple hours or so.
&&
.MARINE...12/230 AM.
Small craft advisory conditions are not likely through Saturday
morning...though occasional afternoon and evening gusts around 20
KT are expected from Point Conception to San Clemente Island.
high confidence that Northwest winds will increase Saturday
through early next week. Small craft advisory winds are certain
from the central coast to San Nicolas island...with a 30 percent
chance of low-grade gale force winds. There is a 60 percent
chance for small craft advisory winds over the other inner
waters. All waters will see building short- period and hazardously
choppy seas.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.
&&
$$
PUBLIC...RAT
AVIATION...CK
MARINE...CK
SYNOPSIS...RAT
weather.gov/losangeles
Area Forecast Discussion
National Weather Service San Francisco Bay Area
416 AM PDT THU MAY 12 2016
.Synopsis...2000 foot marine layer remains in place this morning
with clearing by late morning as high pressure continues. Next
trough arrives Friday with a cooling trend as onshore winds
return. The trough will move onshore Saturday morning and could
produce some North Bay sprinkles with drizzle along the coast.
High pressure rebuilds Sunday through the middle of next week with
dry and seasonable weather.
&&
.Discussion...AS OF 4:16 am pdt Thursday...2000 foot marine layer
in place with cloud bases from 500 to 1000 feet this morning. High
pressure aloft will likely induce some drizzle this morning as the
sun comes up. Otherwise clouds will burn off by late morning
inland areas and retreat to the coast. Inland highs mainly in the
70s except some 80s well inland while 60s persist along the coast.
Main weather story for Friday will be an inland cooling trend as
onshore flow increases ahead of approaching upper trough. Cool
marine air should efficiently spread into the Bay and inland
valleys with the afternoon/evening seabreeze on Friday ahead of
the upper trough as the marine layer deepens.
Upper trough axis passes near Cape Mendocino early Saturday
morning. NAM model has painted some spotty qpf over Sonoma County
as this occurs so have put some 15% chance of sprinkles or light
showers Saturday morning as the trough axis moves inland and may
produce some showers or just lift the marine layer and produce
some light precip. Otherwise expect a partly cloudy and cool day
on Saturday with highs in the 60s to lower 70s.
High pressure rebuilds behind the trough on Sunday leading to a
prolonged period of dry and seasonable weather through most of
next week. Latest long range trends show next upper trough
arriving late next week but precip staying north of the Bay Area.
Main extended theme would be below normal temps with no hot
weather through the weekend of the 22nd.
&&
.Aviation...As of 11:00 PM PDT Wednesday...A deep marine layer
(around 2000 feet) and moderate onshore flow will mean widespread
MVFR and local IFR cigs overnight and through Thursday morning.
Marine layer depth not expected to change much over the next 24
hours, which will mean relatively slow clearing of low cigs on
Thursday with little or no clearing near the ocean. Light to
moderate onshore winds will prevail.
Vicinity of KSFO...MVFR cigs expected to develop by 09Z and
continue until 18Z Thursday. A period of IFR cigs is possible from
12Z-17Z. Confidence moderate. Light westerly winds overnight
increasing to about 15 knots late Thursday afternoon.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...IFR cigs persisting overnight and through
most of Thursday morning. MVFR cigs likely through the
afternoon...possibly scattering out for a few hours mid to late
afternoon. Light westerly winds.
&&
.Marine...as of 03:34 AM PDT Thursday...Weak high pressure over
the great basin and off the california coast will keep light
northwest winds through saturday. winds will increase sunday and
monday as high pressure strengthens off the california coast. a
long period southerly swell will move through the coastal waters
at times.
&&
.MTR Watches/Warnings/Advisories...
.Tday...None.
$$
Public Forecast: RWW
Aviation: W Pi
Marine: W Pi
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
416 AM PDT THU MAY 12 2016
.Synopsis...2000 foot marine layer remains in place this morning
with clearing by late morning as high pressure continues. Next
trough arrives Friday with a cooling trend as onshore winds
return. The trough will move onshore Saturday morning and could
produce some North Bay sprinkles with drizzle along the coast.
High pressure rebuilds Sunday through the middle of next week with
dry and seasonable weather.
&&
.Discussion...AS OF 4:16 am pdt Thursday...2000 foot marine layer
in place with cloud bases from 500 to 1000 feet this morning. High
pressure aloft will likely induce some drizzle this morning as the
sun comes up. Otherwise clouds will burn off by late morning
inland areas and retreat to the coast. Inland highs mainly in the
70s except some 80s well inland while 60s persist along the coast.
Main weather story for Friday will be an inland cooling trend as
onshore flow increases ahead of approaching upper trough. Cool
marine air should efficiently spread into the Bay and inland
valleys with the afternoon/evening seabreeze on Friday ahead of
the upper trough as the marine layer deepens.
Upper trough axis passes near Cape Mendocino early Saturday
morning. NAM model has painted some spotty qpf over Sonoma County
as this occurs so have put some 15% chance of sprinkles or light
showers Saturday morning as the trough axis moves inland and may
produce some showers or just lift the marine layer and produce
some light precip. Otherwise expect a partly cloudy and cool day
on Saturday with highs in the 60s to lower 70s.
High pressure rebuilds behind the trough on Sunday leading to a
prolonged period of dry and seasonable weather through most of
next week. Latest long range trends show next upper trough
arriving late next week but precip staying north of the Bay Area.
Main extended theme would be below normal temps with no hot
weather through the weekend of the 22nd.
&&
.Aviation...As of 11:00 PM PDT Wednesday...A deep marine layer
(around 2000 feet) and moderate onshore flow will mean widespread
MVFR and local IFR cigs overnight and through Thursday morning.
Marine layer depth not expected to change much over the next 24
hours, which will mean relatively slow clearing of low cigs on
Thursday with little or no clearing near the ocean. Light to
moderate onshore winds will prevail.
Vicinity of KSFO...MVFR cigs expected to develop by 09Z and
continue until 18Z Thursday. A period of IFR cigs is possible from
12Z-17Z. Confidence moderate. Light westerly winds overnight
increasing to about 15 knots late Thursday afternoon.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...IFR cigs persisting overnight and through
most of Thursday morning. MVFR cigs likely through the
afternoon...possibly scattering out for a few hours mid to late
afternoon. Light westerly winds.
&&
.Marine...as of 03:34 AM PDT Thursday...Weak high pressure over
the great basin and off the california coast will keep light
northwest winds through saturday. winds will increase sunday and
monday as high pressure strengthens off the california coast. a
long period southerly swell will move through the coastal waters
at times.
&&
.MTR Watches/Warnings/Advisories...
.Tday...None.
$$
Public Forecast: RWW
Aviation: W Pi
Marine: W Pi
Visit us at www.weather.gov/sanfrancisco
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Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
400 am PDT Thu May 12, 2016
.SYNOPSIS...
High pressure will keep skies generally clear and temperatures
above normal through Friday. A dry cold front will move through
the central california interior Saturday accompanied and followed
by gusty winds on the west side of the San Joaquin Valley and in
the Kern County mountains and desert thIS weekend. Temperatures
will cool to seasonable levels by Sunday.
&&
.DISCUSSION...A very warm day, and likely the warmest day yet this
year, is shaping up over the central California interior as evidenced
by temperature trends which are currently averaging 3 to 8 degrees
higher than 24 hours ago. Friday will be nearly as warm as today and
possibly even a bit warmer in the Kern County Desert as the center
of an upper level ridge of high pressure currently over California
shifts eastward into the Great Basin. During this time, thermometer
readings will rise well into the 90`s in the San Joaquin Valley,
lower foothills and the Kern County Desert. The hottest locations
could reach the century mark in the San Joaquin Valley this afternoon
and in the Kern County Desert Friday afternoon.
Our preview of Summer weather will be short-lived, only to be ushered
away by a cold front Saturday. That front is currently situated over
the Eastern Pacific and will be carried eastward across the central
California interior by a storm system that tracks through the
Pacific Northwest this weekend. The cold front will be moisture
starved by the time it arrives here Saturday afternoon and will be
accompanied by little more than some mid and high cloudiness with its
passage. Nonetheless, the front will be driven through the CWA by a
rather strong upper level jet Saturday. The models forecast this 300
mb jet to remain over central California through the weekend thus
supporting gusty winds through and below the passes on the west side
of the San Joaquin Valley and in the Kern County mountains and
desert. In these specific regions, wind gusts might briefly breach
advisory speeds of 35 to 45 mph from Saturday evening through Sunday
evening and kick up some dust. In addition to blustery winds, the
cold front will herald the arrival of a much cooler air mass this
weekend. High temperatures will be a good 10 to 20 degrees lower
Sunday compared to today and Friday. Additionally, low clouds and
possibly some drizzle could form in the wake of this cold front
along the north facing slopes of the Tehachapi mountains Saturday
night and linger through midday Sunday.
Monday will still be rather breezy and slightly cooler than normal as
a dry northwesterly flow aloft resides over California. The models
bring a weak "inside slider" type disturbance into the Great Basin
Monday. If this system tracks a little farther west than we are
currently thinking, it could bring some showers to the higher
elevations of the Sierra north of Kings Canyon Monday afternoon into
Monday night. We are currently opting for a dry forecast but have
beefed up cloud cover over the high Sierra during these periods for
now.
Tuesday through Wednesday will be dry as an Epac ridge builds into
California. A warming trend during this period will bring maximum
temperatures close to the ninety degree mark again in the San Joaquin
Valley by Wednesday. Although the models flatten this ridge by next
Thursday, mostly clear skies and warmer than normal temperatures
will continue on day 7. The models forecast a return of blustery
and much cooler weather across central California toward the end of
next week as an unusually deep and cold storm system moves into the
Pacific Northwest. Further details on that will be reserved for later
forecast discussions.
&&
.AVIATION...
VFR conditions can be expected throughout the central CA interior
during the next 24 hours.
&&
.AIR QUALITY ISSUES...
ON THURSDAY MAY 12 2016... UNHEALTHY FOR SENSITIVE GROUPS IN
FRESNO... KERN... KINGS... MADERA... MERCED AND TULARE COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.CERTAINTY...
The level of certainty for days 1 and 2 is high.
The level of certainty for days 3 through 7 is high.
Certainty levels include low...medium...and high. Please visit
www.weather.gov/hnx/certainty.php for additional information
an/or to provide feedback.
&&
.HNX Watches/Warnings/Advisories...
NONE.
&&
$$
public...Durfee
avn/fw...DS
synopsis...Durfee
weather.gov/hanford
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
400 am PDT Thu May 12, 2016
.SYNOPSIS...
High pressure will keep skies generally clear and temperatures
above normal through Friday. A dry cold front will move through
the central california interior Saturday accompanied and followed
by gusty winds on the west side of the San Joaquin Valley and in
the Kern County mountains and desert thIS weekend. Temperatures
will cool to seasonable levels by Sunday.
&&
.DISCUSSION...A very warm day, and likely the warmest day yet this
year, is shaping up over the central California interior as evidenced
by temperature trends which are currently averaging 3 to 8 degrees
higher than 24 hours ago. Friday will be nearly as warm as today and
possibly even a bit warmer in the Kern County Desert as the center
of an upper level ridge of high pressure currently over California
shifts eastward into the Great Basin. During this time, thermometer
readings will rise well into the 90`s in the San Joaquin Valley,
lower foothills and the Kern County Desert. The hottest locations
could reach the century mark in the San Joaquin Valley this afternoon
and in the Kern County Desert Friday afternoon.
Our preview of Summer weather will be short-lived, only to be ushered
away by a cold front Saturday. That front is currently situated over
the Eastern Pacific and will be carried eastward across the central
California interior by a storm system that tracks through the
Pacific Northwest this weekend. The cold front will be moisture
starved by the time it arrives here Saturday afternoon and will be
accompanied by little more than some mid and high cloudiness with its
passage. Nonetheless, the front will be driven through the CWA by a
rather strong upper level jet Saturday. The models forecast this 300
mb jet to remain over central California through the weekend thus
supporting gusty winds through and below the passes on the west side
of the San Joaquin Valley and in the Kern County mountains and
desert. In these specific regions, wind gusts might briefly breach
advisory speeds of 35 to 45 mph from Saturday evening through Sunday
evening and kick up some dust. In addition to blustery winds, the
cold front will herald the arrival of a much cooler air mass this
weekend. High temperatures will be a good 10 to 20 degrees lower
Sunday compared to today and Friday. Additionally, low clouds and
possibly some drizzle could form in the wake of this cold front
along the north facing slopes of the Tehachapi mountains Saturday
night and linger through midday Sunday.
Monday will still be rather breezy and slightly cooler than normal as
a dry northwesterly flow aloft resides over California. The models
bring a weak "inside slider" type disturbance into the Great Basin
Monday. If this system tracks a little farther west than we are
currently thinking, it could bring some showers to the higher
elevations of the Sierra north of Kings Canyon Monday afternoon into
Monday night. We are currently opting for a dry forecast but have
beefed up cloud cover over the high Sierra during these periods for
now.
Tuesday through Wednesday will be dry as an Epac ridge builds into
California. A warming trend during this period will bring maximum
temperatures close to the ninety degree mark again in the San Joaquin
Valley by Wednesday. Although the models flatten this ridge by next
Thursday, mostly clear skies and warmer than normal temperatures
will continue on day 7. The models forecast a return of blustery
and much cooler weather across central California toward the end of
next week as an unusually deep and cold storm system moves into the
Pacific Northwest. Further details on that will be reserved for later
forecast discussions.
&&
.AVIATION...
VFR conditions can be expected throughout the central CA interior
during the next 24 hours.
&&
.AIR QUALITY ISSUES...
ON THURSDAY MAY 12 2016... UNHEALTHY FOR SENSITIVE GROUPS IN
FRESNO... KERN... KINGS... MADERA... MERCED AND TULARE COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.CERTAINTY...
The level of certainty for days 1 and 2 is high.
The level of certainty for days 3 through 7 is high.
Certainty levels include low...medium...and high. Please visit
www.weather.gov/hnx/certainty.php for additional information
an/or to provide feedback.
&&
.HNX Watches/Warnings/Advisories...
NONE.
&&
$$
public...Durfee
avn/fw...DS
synopsis...Durfee
weather.gov/hanford
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
400 am PDT Thu May 12, 2016
.SYNOPSIS...
High pressure will keep skies generally clear and temperatures
above normal through Friday. A dry cold front will move through
the central california interior Saturday accompanied and followed
by gusty winds on the west side of the San Joaquin Valley and in
the Kern County mountains and desert thIS weekend. Temperatures
will cool to seasonable levels by Sunday.
&&
.DISCUSSION...A very warm day, and likely the warmest day yet this
year, is shaping up over the central California interior as evidenced
by temperature trends which are currently averaging 3 to 8 degrees
higher than 24 hours ago. Friday will be nearly as warm as today and
possibly even a bit warmer in the Kern County Desert as the center
of an upper level ridge of high pressure currently over California
shifts eastward into the Great Basin. During this time, thermometer
readings will rise well into the 90`s in the San Joaquin Valley,
lower foothills and the Kern County Desert. The hottest locations
could reach the century mark in the San Joaquin Valley this afternoon
and in the Kern County Desert Friday afternoon.
Our preview of Summer weather will be short-lived, only to be ushered
away by a cold front Saturday. That front is currently situated over
the Eastern Pacific and will be carried eastward across the central
California interior by a storm system that tracks through the
Pacific Northwest this weekend. The cold front will be moisture
starved by the time it arrives here Saturday afternoon and will be
accompanied by little more than some mid and high cloudiness with its
passage. Nonetheless, the front will be driven through the CWA by a
rather strong upper level jet Saturday. The models forecast this 300
mb jet to remain over central California through the weekend thus
supporting gusty winds through and below the passes on the west side
of the San Joaquin Valley and in the Kern County mountains and
desert. In these specific regions, wind gusts might briefly breach
advisory speeds of 35 to 45 mph from Saturday evening through Sunday
evening and kick up some dust. In addition to blustery winds, the
cold front will herald the arrival of a much cooler air mass this
weekend. High temperatures will be a good 10 to 20 degrees lower
Sunday compared to today and Friday. Additionally, low clouds and
possibly some drizzle could form in the wake of this cold front
along the north facing slopes of the Tehachapi mountains Saturday
night and linger through midday Sunday.
Monday will still be rather breezy and slightly cooler than normal as
a dry northwesterly flow aloft resides over California. The models
bring a weak "inside slider" type disturbance into the Great Basin
Monday. If this system tracks a little farther west than we are
currently thinking, it could bring some showers to the higher
elevatins of the Sierra north of Kings Canyon Monday afternoon into
Monday night. We are currently opting for a dry forecast but have
beefed up cloud cover over the high Sierra during these periods for
now.
Tuesday through Wednesday will be dry as an Epac ridge builds into
California. A warming trend during this period will bring maximum
temperatures close to the ninety degree mark again in the San Joaquin
Valley by Wednesday. Although the models flatten this ridge by next
Thursday, mostly clear skies and warmer than normal temperatures
will continue on day 7. The models forecast a return of blustery
and much cooler weather across central California toward the end of
next week as an unusually deep and cold storm system moves into the
Pacific Northwest. Further details on that will be reserved for later
forecast discussions.
&&
.AVIATION...
VFR conditions can be expected throughout the central CA interior
during the next 24 hours.
&&
.AIR QUALITY ISSUES...
ON THURSDAY MAY 12 2016... UNHEALTHY FOR SENSITIVE GROUPS IN
FRESNO... KERN... KINGS... MADERA... MERCED AND TULARE COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.CERTAINTY...
The level of certainty for days 1 and 2 is high.
The level of certainty for days 3 through 7 is high.
Certainty levels include low...medium...and high. Please visit
www.weather.gov/hnx/certainty.php for additional information
an/or to provide feedback.
&&
.HNX Watches/Warnings/Advisories...
NONE.
&&
$$
public...Durfee
avn/fw...DS
synopsis...Durfee
weather.gov/hanford
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
400 am PDT Thu May 12, 2016
.SYNOPSIS...
High pressure will keep skies generally clear and temperatures
above normal through Friday. A dry cold front will move through
the central california interior Saturday accompanied and followed
by gusty winds on the west side of the San Joaquin Valley and in
the Kern County mountains and desert thIS weekend. Temperatures
will cool to seasonable levels by Sunday.
&&
.DISCUSSION...A very warm day, and likely the warmest day yet this
year, is shaping up over the central California interior as evidenced
by temperature trends which are currently averaging 3 to 8 degrees
higher than 24 hours ago. Friday will be nearly as warm as today and
possibly even a bit warmer in the Kern County Desert as the center
of an upper level ridge of high pressure currently over California
shifts eastward into the Great Basin. During this time, thermometer
readings will rise well into the 90`s in the San Joaquin Valley,
lower foothills and the Kern County Desert. The hottest locations
could reach the century mark in the San Joaquin Valley this afternoon
and in the Kern County Desert Friday afternoon.
Our preview of Summer weather will be short-lived, only to be ushered
away by a cold front Saturday. That front is currently situated over
the Eastern Pacific and will be carried eastward across the central
California interior by a storm system that tracks through the
Pacific Northwest this weekend. The cold front will be moisture
starved by the time it arrives here Saturday afternoon and will be
accompanied by little more than some mid and high cloudiness with its
passage. Nonetheless, the front will be driven through the CWA by a
rather strong upper level jet Saturday. The models forecast this 300
mb jet to remain over central California through the weekend thus
supporting gusty winds through and below the passes on the west side
of the San Joaquin Valley and in the Kern County mountains and
desert. In these specific regions, wind gusts might briefly breach
advisory speeds of 35 to 45 mph from Saturday evening through Sunday
evening and kick up some dust. In addition to blustery winds, the
cold front will herald the arrival of a much cooler air mass this
weekend. High temperatures will be a good 10 to 20 degrees lower
Sunday compared to today and Friday. Additionally, low clouds and
possibly some drizzle could form in the wake of this cold front
along the north facing slopes of the Tehachapi mountains Saturday
night and linger through midday Sunday.
Monday will still be rather breezy and slightly cooler than normal as
a dry northwesterly flow aloft resides over California. The models
bring a weak "inside slider" type disturbance into the Great Basin
Monday. If this system tracks a little farther west than we are
currently thinking, it could bring some showers to the higher
elevatins of the Sierra north of Kings Canyon Monday afternoon into
Monday night. We are currently opting for a dry forecast but have
beefed up cloud cover over the high Sierra during these periods for
now.
Tuesday through Wednesday will be dry as an Epac ridge builds into
California. A warming trend during this period will bring maximum
temperatures close to the ninety degree mark again in the San Joaquin
Valley by Wednesday. Although the models flatten this ridge by next
Thursday, mostly clear skies and warmer than normal temperatures
will continue on day 7. The models forecast a return of blustery
and much cooler weather across central California toward the end of
next week as an unusually deep and cold storm system moves into the
Pacific Northwest. Further details on that will be reserved for later
forecast discussions.
&&
.AVIATION...
VFR conditions can be expected throughout the central CA interior
during the next 24 hours.
&&
.AIR QUALITY ISSUES...
ON THURSDAY MAY 12 2016... UNHEALTHY FOR SENSITIVE GROUPS IN
FRESNO... KERN... KINGS... MADERA... MERCED AND TULARE COUNTIES.
FURTHER INFORMATION IS AVAILABLE AT VALLEYAIR.ORG
&&
.CERTAINTY...
The level of certainty for days 1 and 2 is high.
The level of certainty for days 3 through 7 is high.
Certainty levels include low...medium...and high. Please visit
www.weather.gov/hnx/certainty.php for additional information
an/or to provide feedback.
&&
.HNX Watches/Warnings/Advisories...
NONE.
&&
$$
public...Durfee
avn/fw...DS
synopsis...Durfee
weather.gov/hanford
Area Forecast Discussion
National Weather Service Eureka CA
404 AM PDT THU MAY 12 2016
.DISCUSSION...Low clouds and patchy fog/light drizzle have
expanded eastward from the coastal waters, roughly along and west
of the U.S. 101 corridor, and may continue to spread inland
somewhat over the next few hours. We added patchy fog with light
drizzle to the zones for these locations. By mid-morning, the fog
should being to burn off, with any residual fog being confined to
the immediate coastal areas. Otherwise, expect clouds to persist
today/tonight with near seasonal temperatures.
For Friday through next weekend, rain chances will increase for
Friday through the weekend. Not too much has changed in the latest
model runs, as they continue to portray an upper-level low passing
by to our north, with a respectable jet stream positioned across
northern California. As the system approached the coast Friday
evening, showers and isolated thunderstorms will develop during
the afternoon and evening. The best chance for thunderstorm
development continues to be across eastern portions of Del Norte
and Trinity counties. Taking a look at model soundings for this
area, they continue to show moderate instability, with NAM MUCAPEs
ranging from 500 to 2000 J/kg (highest across northern portions of
Trinity County). However...the GFS is less aggressive with these
values, showing about 500-1200 J/kg. In any event, both models
show good directional shear above 850mb which will aloft for good
tilting of the updraft (storm top ventilation), which combined
with 0-6km bulk shear values near 30 kts may result in a couple of
strong storms. Mid-level lapse rates today are lower than
yesterday (models now show less than 7 deg C/km), thus, severe
weather is not expected at this time.
As the system moves ashore Friday night/Saturday it will begin to
take on a negative tilt. Increasing ascent associated with this may
allow a few thunderstorms to develop despite decreasing instability.
Showers will also increase in coverage as the trough axis crosses
the state. Any precipitation will decrease in coverage on Sunday, as
the system departs the region. Upper-level ridging will start to
build across the region by early next week, with rising height
leading to warmer temperatures and decreased cloud cover. /PD
&&
.AVIATION...Marine layer is well established along the coastal forecast
area overnight. LIFR conditions were observed in both Crescent
City and Arcata airports. Cloud ceiling is steady at around 200
feet. Around 1 to 2 mile visibilities at Crescent City, and Arcata
saw visibilities as low as 1/4 mile at times. Being further
inland, Ukiah is seeing VFR conditions with mostly clear skies and
unrestricted visibilities. During the day, do expect gradually
improving conditions for Crescent City and Arcata, as the daytime
heating should erode the marine stratus somewhat. However, do
expect the marine stratus to strengthen overnight tonight as there
is not really any strong offshore wind component to cause the
marine layer to dissipate. /RL
&&
.MARINE...Light winds with low seas expected through Friday.
Seas, around 4 feet or so, are mixed with short, mid and long
period groups. Across Northern California and coastal waters,
there is not much pressure gradient. The weak pressure gradient is
expected to continue through Friday. On Saturday, a weak low
pressure will approach Northwest California coast, and this will
bring in southerly winds across the coastal waters. Northerly
winds will return to the area by Sunday, as the low moves inland
and a high builds into the East Pacific. Models are hinting that
northerly winds will increase to small craft level by Monday, with
gale force winds possible. Short period waves of 8 feet or higher
should return to the area early next week due to the increase in
northerly winds.
Visibilities are lowered this morning due to low clouds and light
drizzle from the marine layer covering the Northwest California
coast. The marine layer is expected to remain over the area
through tonight at the very least, since there is not really any
major atmospheric forcing that will lead to the dissipation of the
marine layer.
Forecast confidence is about average. Utilize RUC13 through
Thursday afternoon, then transition to Hi-Res ARW and Hi-Res NMM
through Thursday night. Uses a blend of ECMWF/GFS from Friday
through next week. /RL
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...NONE.
&&
$$
Visit us at http://WWW.WEATHER.GOV/EUREKA
Follow us on facebook and twitter at:
http://www.facebook.com/NWSEureka
http://www.twitter.com/nwseureka
FOR FORECAST ZONE INFORMATION
SEE FORECAST ZONE MAP ONLINE:
http://www.weather.gov/eureka/zonemap.png
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
631 PM CDT FRI MAY 13 2016
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Saturday)
Issued at 154 PM CDT FRI MAY 13 2016
Pre-frontal thunderstorm activity will continue to push east
through mid-afternoon. Some of this pre-frontal activity still
maintains some potential for severe hail, although the better
potential may be a bit later this afternoon along the incoming
strong cold front.
Storms will form along a cold front passing through the area this
afternoon and evening. The models have been fairly consistent with
the timing of the front, which will be the focus for the storms.
Expected surface based development around 2 to 3 pm this
afternoon across northern KS. Ahead of the front a few elevated
showers and storms have formed and will move east across the area.
These may be capable of producing hail and isolated wind, but the
coverage is very uncertain although should remain isolated. More
widely scattered storms will be present along the front. The
models have been overestimating the dew points, which are
currently in the lower 50s. There is a chance they may increase to
the mid 50s in the next few hours. Given these dew points the
mlcape should reach 1000 to 1500 j/kg. The deep layer shear is
around 40 to 50 kts and should be sufficient to support some
severe storms. Soundings show mainly a straight line hodographs
with slight curvature in the lowest levels. Therefore expect that
left and right moving storms will be possible if able to rotate
aloft. Soundings would suggest a high storm base given they are
overestimating the dew points. The main threat will be large hail
and damaging wind with a very low tornado threat. Several of the
high res models have highlighted decent max updraft helicity
swaths, and max 10 m wind gusts approaching severe limits moving
across most of the area with these storms. Storms will be moving
southeast at 30 to 40 kts therefore do not expect any flooding.
Expect most of the storms will weaken and move out of the forecast
area by 7 pm this evening.
.LONG TERM...(Saturday Night through Friday)
Issued at 154 PM CDT FRI MAY 13 2016
On Saturday, a weak upper wave and upper level frontogenesis will
provide lift in the mid and upper levels across parts of the area.
This will induce mid-level saturation and cloud cover, and will try
to produce light precipitation. However, very dry air below the
cloud layer should be quite effective in evaporation so have reduced
pops and included mention of sprinkles across parts of the area on
Saturday. Clouds and plenty of cold advection will keep temperatures
much cooler and a persistent north breeze will add to the cool
feeling conditions. Highs are likely to top out in the upper 50s to
around 60.
Skies are likely to clear out in the northeast Saturday night but
additional clouds will build in from the southwest over time as
elevated moisture advects into the area ahead of the next incoming
wave. This should allow temperatures to become quite chilly by
Sunday morning especially in low lying areas of northeast KS where
upper 30s are possible. The chilly start and incoming clouds will
make for quite a cool day on sunday. Have reduced pops on Sunday
during the day as dry air should hold strong and the better lift
seems to delay until Sunday night. By Sunday night the better lift
and moisture will make it into the area with increasing rain chances
through the night and much better chances into Monday. CAPE is
limited through this period and expect thunder to hold off for the
most part although one or two storms are possible.
Little change to the later portions of the forecast period given
incoming severe weather potential this afternoon, but will see
additional chances for rain and perhaps some thunderstorms through
the long term as the slow moving southwest trough makes its way
across the forecast area over a multi-day period.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday Evening)
Issued at 624 PM CDT FRI MAY 13 2016
For the 00Z TAFs, expecting VFR conditions with winds calming in
the next couple hours. Generally NNW flow will continue but with
the center of the high near have left gusts out. Also, KMHK could
see a period of showers in the morning, but confidence too low at
this time to mention.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Sanders
LONG TERM...Barjenbruch
AVIATION...Drake
[top]
Area Forecast Discussion
National Weather Service Goodland KS
521 PM MDT FRI MAY 13 2016
.SHORT TERM...(This evening through Saturday)
Issued at 1235 PM MDT Fri May 13 2016
18Z water vapor imagery and RAP analysis indicated northwesterly
flow aloft prevailing across the region. At the surface cold
front had completely cleared the area with northerly winds of 20
to 30 mph across much of the area. Temperatures at most locations
have already fallen 10 degrees or so and any additional warming is
not expected.
H7-H6 frontal zone may become active during the overnight hours as
small pocket of instability develops near MCK. Not overly
confident on measurable amounts as even `wetter` models only
generating a few hundredths of precipitation and several produce
none. More of a potential impact overnight tonight will be
temperatures as sfc high behind todays front will bring a period
of light to calm winds to the area. Think cloud cover will
mitigate any frost threat, but do expect a few locations to dip
down into the 34-36 degree range for an hour or two.
Light winds will gradually become southeasterly and increase
through the day Saturday, although bulk of area will remain under
15 mph for a good portion of the day. For the most part expect dry
and cool conditions to prevail...although moist low levels under
pocket of dry air btwn H7 and H5 does present potential for
instability. Bufkit soundings indicate some elevated cape
throughout the day but lack of any significant trigger prevents
much confidence in any instability being realized.
.LONG TERM...(Saturday night through Friday)
Issued at 211 PM MDT Fri May 13 2016
Saturday night-Tuesday: The combination of a trough building
across the western US and NW flow across the northern plains will
keep reinforcing shots of cooler air moving through the region
with a stalled front west and south of our CWA through these
periods. As the trough in the west deepens southeast then eastern
flow will advect a moist air mass into our CWA.
Based on model profiles, Saturday night through Sunday may see
moisture limited to below 700mb. At the same time, there is
enough depth of the moist layer and frontogenesis within this
layer to support light precip process. Above this layer there is a
conditionally unstable layer that if saturation takes place
convective showers could develop Sunday afternoon. Models continue
to show a light precip signal and I didn`t see a reason to leave
out a mention of precip. The stronger precip signal is closer to
frontal zone in our south where I kept chance pops through Sunday
afternoon. By Sunday night deeper moisture and forcing overspread
our CWA with a stronger precip signal by Monday and Monday night
(when I have likely PoPs). Moderate rainfall will be possible,
particularly in the south where models are showing better elevated
instability. With front remaining well south it is unlikely we
would see enough instability this far north to have a severe
weather concern (at this time).
Tuesday night-Friday: By Tuesday night split flow type pattern
begins to develop across the plains as the closed upper low drifts
southwest and eventually gets caught in the southern jet stream
(tracking well south of our CWA). The pattern eventually shifts
again as another trough begins to develop across the Pacific
Northwest. There is higher model spread in the later periods, but
there is enough considering in rising temperatures back to
seasonal values. I have less confidence in PoPs at this range. Lee
trough does redevelop and models are showing better
instability...so with any weak forcing we could see thunderstorm
development despite the lack of large scale forcing. Mesoscale
details at this range are uncertain...so I was comfortable holding
onto slight chance PoPs inherited by blend to cover potential.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 517 PM MDT Fri May 13 2016
VFR conditions expected for the TAFs. Winds will be light through
the majority of the TAF. Winds at KGLD will increase some during
the mid to late morning Saturday. KMCK will have light and
variable winds during the overnight hours as a surface ridge moves
through. The light and variable winds will continue at KMCK for
the rest of the TAF.
There could be some light rain showers at KMCK overnight. Latest
model data indicates these showers may be east of KMCK. Will wait
for the 0z run of new data before placing a mention in the TAF.
&&
.GLD Watches/Warnings/Advisories...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...DR
AVIATION...JTL
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
333 PM CDT THU MAY 12 2016
.SHORT TERM...(This Evening through Friday)
Issued at 313 PM CDT THU MAY 12 2016
Surface high pressure currently migrating east southeastward across
southern KS and eventually working into the southern plains
overnight. On the western periphery of this high return flow will
develop. Despite the flow being cut off from the gulf there is still
some moisture in western TX/eastern NM evident from Midland`s 12z
sounding. A northern shortwave will push a front into the area
tomorrow afternoon and evening. Southwest flow ahead of this front
should allow that moisture to reach eastern KS. A majority of the
models are forecasting dew points around 60, which seems a little
high, although there is some uncertainty regarding these numbers.
The most likely scenario is dew points in the upper 50s. This
moisture and daytime heating should allow the cap to break along the
front. The only exception to this will be central KS, therefore
coverage may be more isolated there. Further east the cap appears
weaker and forcing stronger to allow for more scattered storms. If
the dew points are lower than the going forecast then the cape will
be less and coverage will be more isolated. As of now the mlcape
could reach 1500-2000 j/kg depending on the dew points, and the deep
layer shear will be around 40 kts. This combination could favor some
strong storms and or supercell development. Several of the high res
models highlight updraft helicity in far eastern KS associated with
these possible storms. The area of development should be mid
afternoon somewhere near a line from Seneca to Abilene, and once
formed will move southeastward with the front. The severe potential
will be slightly further to the southeast of this line. Given the
lower moisture quality the storms will be somewhat high based. This
will favor a damaging wind threat, and the cape/shear combo could
favor large hail as well. The front and storms should clear the area
around 10pm to 12am.
.LONG TERM...(Friday Night through Thursday)
Issued at 313 PM CDT THU MAY 12 2016
Friday Night through Sunday...
The cold front will push all the way through the forecast area by
midnight Friday with persistent cold advection and a low level 10
mph breeze through the night. Temperatures will be cool but the well-
mixed airmass should keep lows in the lower 40s and not much cooler.
A weak secondary short wave aloft will cross the area early Saturday
and will work with the temperature gradient aloft to produce weak
lift and associated saturation beneath a plume of steep lapse rates.
All of this will occur above 700 mb though, and with plenty of dry
air beneath this feature, believe it will be difficult to get much
in the way of rain. Have a slight chance of showers for this period
although it may be more in the form of sprinkles. Saturday will be
plenty cool with highs in the upper 50s to around 60 and a continued
north breeze along with partly to mostly cloudy skies. On Saturday
night, the surface high builds directly over the forecast area with
winds becoming nearly calm. Skies should be clear in the evening
although do expect late moisture return from the SW to begin to
bring clouds into the area closer to sunrise. All of these
conditions should allow temperatures to approach 40 and possibly
even upper 30s in low-lying areas on Sunday morning with the primary
question at the moment being timing of cloud cover. These clouds are
in response to a short wave moving through the zonal flow and
bringing moisture up over the surface cold/dry dome. Lift may be
sufficient during the day on Sunday to produce scattered showers,
although the chances will be better with southwestward extent as the
low level airmass will be quite dry and there is little to no
instability present.
Sunday Night through Thursday...
A broad, low-amplitude trough will be located over the western US at
the beginning of the period. At the same time a 500mb jet max will
be located over the Great Lakes region. A few showers and isolated
thunderstorms will be possible Sunday night as weak lead waves and
large scale ascent associated with the right entrance region of the
jet remain over the area. Model agreement increasing in regards to
evolution of Monday afternoon/evening. Current runs suggest moisture
return will be limited Monday afternoon/evening with dewpoints
forecast to be in 40s. With that being said, have likely PoPs Monday
night/Tuesday morning as large scale ascent and multiple shortwaves
overspread the central plains. Model agreement then diverges greatly
for the remainder of the period. GFS maintains upper level trough
and pushes it across the area by Thursday. This solution creates on
and off shower and thunderstorm chances through Thursday. While the
ECMWF weakens the trough and replaces it with zonal flow and dry
conditions across area. However, have continued at least slight
chance PoPs through the end of the period. Temperatures will remain
cool with highs in the 60s to near 70 and lows in the mid-40s to low-
50s.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon)
Issued at 1211 PM CDT THU MAY 12 2016
VFR conditions expected through the period.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Sanders
LONG TERM...Barjenbruch/Baerg
AVIATION...Sanders
Area Forecast Discussion
National Weather Service Goodland KS
232 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 18Z TAFS through 18Z Friday afternoon)
Issued at 1130 AM MDT Thu May 12 2016
VFR conditions expected for the next 24 hours with somewhat
variable winds expected through the overnight hours...followed by
period of strong northerly winds in the late morning hours as cold
front sweeps through the area. Will see scattered cumulus field
through 00z...with heights btwn 4000 and 5000 feet and gradually
rising through the day.
&&
.GLD Watches/Warnings/Advisories...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...DR
AVIATION...JRM
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
551 AM CDT THU MAY 12 2016
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 310 AM CDT THU MAY 12 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...(Friday through Wednesday)
Issued at 310 AM CDT THU MAY 12 2016
On Friday, surface high pressure will have moved southeast of the
area as an area of low pressure located in central Nebraska begins
to move towards northeast Kansas. As this cold frontal boundary
passes, showers and thunderstorms are expected to develop. While
moisture is limited ahead of this surface front, a sharp gradient of
instability and 0-6 km shear of 40-50 kts may allow for some
stronger to severe storms to develop, mainly in east central Kansas.
Soundings indicate storms will be elevated with steep lapse rates
near the surface making strong winds and hail the main threats
Friday. By late Friday evening, any storms will be southeast of the
forecast area and cold air will begin to usher in behind the front.
Highs drop significantly on Saturday into the upper 50s and low 60s.
There is a small chance for showers early morning Saturday as a very
subtle wave passes over the area.
From here, the only dry time for the rest of the period looks to be
Saturday afternoon though Sunday morning. Models still do not have
a great handle on the overall pattern for next week, but it appears
that an upper level low over the northwest CONUS will be present
with waves ejecting over the central US. The best chances for
precipitation will be Monday and Tuesday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday Morning)
Issued at 550 AM CDT THU MAY 12 2016
VFR conditions through the period. Added a wind period this
afternoon due to deep mixing which should result in gusty winds
during peak heating. Airmass will quickly decouple this evening.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Johnson
LONG TERM...Heller
AVIATION...Johnson
Area Forecast Discussion
National Weather Service Goodland KS
320 AM MDT THU MAY 12 2016
.SHORT TERM...(Today through Saturday night)
Issued at 320 AM MDT Thu May 12 2016
TODAY-TONIGHT...FORECAST AREA UNDER NORTHWEST FLOW ALOFT WITH
UPPER RIDGE AXIS EXTENDING FROM THE PACIFIC NORTHWEST SOUTHEAST
THROUGH NEW MEXICO AND TROUGHING ACROSS THE NORTHERN PLAINS AND
GREAT LAKES AREA. DRY AIR COVERS THE AREA SO NO PRECIPITATION
EXPECTED. HIGH TEMPERATURES IN THE UPPER 60S TO MID 70S. LOW
TEMPERATURES IN THE LOW 40S TO LOW 50S.
FRIDAY-FRIDAY NIGHT...LITTLE CHANGE IN THE UPPER LEVEL PATTERN WITH
PERHAPS A SLIGHT EASTWARD MOVEMENT OF THE PACIFIC NORTHWEST RIDGE
AXIS AS LOW PRESSURE MOVES TOWARD THE NORTHERN CALIFORNIA COAST. AT
THE SFC A COLD FRONT MOVES SOUTH ACROSS THE AREA DURING THE DAY WITH
A 1025MB SFC HIGH MOVING INTO THE AREA DURING THE NIGHT. THERE IS
SOME MOISTURE IN THE 850-500MB LAYER ACROSS OUR NEBRASKA COUNTIES
DURING THE NIGHT WHICH SUPPORTS AT LEAST A SLIGHT CHANCE FOR SOME
RAIN SHOWERS...MAINLY ACROSS HITCHCOCK AND RED WILLOW COUNTIES.
BETTER PERFORMING BIAS CORRECTED GRIDS THROUGH 7 AND 15 DAYS
SUPPORTS HIGH TEMPERATURES AROUND 70 ALONG THE KS/NE BORDER WITH
UPPER 70S TO AROUND 80 IN GREELEY AND WICHITA COUNTIES. LOW
TEMPERATURES GENERALLY IN THE UPPER 30S TO AROUND 40.
SATURDAY-SATURDAY NIGHT...LOW CLOUDS INCREASE ACROSS THE AREA
THROUGH THE PERIOD. RIGHT NOW IT LOOKS DRY DURING THE DAY BUT DURING
THE NIGHT SLIGHT CHANCE AND CHANCE POPS ARE FORECAST AS MID LEVEL
MOISTURE INCREASES AS A WEATHER DISTURBANCE MOVES NORTHWEST TO
SOUTHEAST ACROSS THE AREA. WITH SFC RIDGE AXIS OVER THE EASTERN PART
OF THE AREA AND ABOVE MENTIONED CLOUD COVER CONSIDERABLY COOLER
TEMPERATURES (COMPARED TO FRIDAY) ARE EXPECTED. AM AIMING FOR HIGHS
IN THE MID 50S TO LOW 60S. LOW TEMPERATURES IN THE LOW 40S.
.LONG TERM...(Sunday through Wednesday)
Issued at 220 AM MDT Thu May 12 2016
For the long term period the GFS and European are in good agreement
Sunday with the placement and track of the closed low pressure
system in the Pacific northwest, as well as the ridge sitting over
the CWA. Come Monday, there are some major differences on the track
of the low. This poses a problem, especially with the potential for
severe weather. The GFS has a much more amplified trough, which has
been the case the last few nights, and the European has a much less
amplified trough that is much more north. With the trough moving in,
even with the differences between the models, there is a plethora of
moisture being pulled up from the Gulf of Mexico that will bring
chances for precipitation to the region Sunday onward. As for the
severe weather potential, Monday is looking like it could be a good
contender. The GFS has CAPE values up to 2200 J/kg around 00Z
Tuesday, bulk shear up to 60 kts, 700 mb open and closed shortwaves
and even DCAPE values reaching 800 J/kg over areas. All of those are
good indicators for potential severe weather but at this time the
certainty that the GFS will be the model that is true to reality is
hard to say, especially since the European is completely different
and temperatures are a little cool. So, as of right now will be
keeping showers as the main precipitation type but having chances
for thunderstorms Monday.
The remainder of the extended period continues to have chances for
precipitation. Wednesday may have a greater potential for
thunderstorms with a closed low moving over Nebraska. Temperatures
are expected to increase from the 50s and 60s Sunday through Tuesday
to the 70s Wednesday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 320 AM MDT Thu May 12 2016
For KGLD and KMCK...vfr conditions expected through the period.
West to southwest winds 10kts or less expected through the period
under a generally clear sky.
&&
.GLD Watches/Warnings/Advisories...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...99
LONG TERM...CLT
AVIATION...99
Area Forecast Discussion
National Weather Service Wichita KS
337 AM CDT THU MAY 12 2016
.SYNOPSIS...
Issued at 250 AM CDT Thu May 12 2016
Upper-level energy has begun to lift northeast this morning with
large-scale subsidence increasing across western Kansas based on
water vapor imagery. Ahead of this upper-level energy, thunderstorms
developed across northern Oklahoma as a cold front continued to
push south of the region. Post frontal dry air has begun to advect
into western and central Kansas as surface high pressure began to
slowly push southeastward.
&&
.SHORT TERM...(Today through Saturday night)
Issued at 250 AM CDT Thu May 12 2016
As shortwave energy lifts out of the central Plains, upper-level subsidence
will increase today as a resulting surface high pressure traverses the
region. With a drier post frontal airmass in place, ample insolation
and downsloping winds expect a pleasant day today with temperatures
climbing into the mid to upper 70s. Tonight as shortwave energy digs
southeast across the northern Plains, longwave upper-level troughing
will become amplified across the central CONUS. As a result, northwest
flow will develop and allow for a cool and dry Canadian airmass to
advect southward across the northern and eventually central Plains.
Based on current model guidance, the cold front associated with this
Canadian airmass is progged to approach central Kansas by the late
morning and early afternoon hours on Friday, before continuing to
track southward across south central and southeast Kansas later Friday
afternoon. Ahead of the cold front, moisture will begin to return
northward as surface high pressure slowly drops southeast of the region.
With a weakly capped atmosphere in place, given the increasing convergence
along the cold front across central Kansas coupled with isentropic
lift and warm/moist air advection, expect storms to develop during
the early to mid afternoon hours across central Kansas. As the front
continues to push south into south central and southeast Kansas later
on Friday, expect thunderstorm activity to become a bit more widespread
and possibly develop into a complex of thunderstorms due to the strong
convergence along the frontal boundary and the aforementioned weak
capping. With at least 1000-2000J/kg and 30-40knots 0-6km bulk shear
a few strong to severe storms will be possible. With forecast soundings
showing classic inverted-V characteristics at low-levels, skinny CAPE
profiles and ample dry mid-level air thinking that damaging winds
will be the primary threat, along with hail.
The surface cold front is expected to drop south into Oklahoma by
Saturday morning. A much cooler airmass will overspread the region
as with afternoon highs will be running about 10 degrees below average
for this time of year. There is a chance that showers and isolated
thunderstorms may redevelop on Saturday, especially across southern
Kansas, due to lingering elevated baroclinic zones. With very little,
if any, in the way of instability to work with have only kept mentions
of isolated thunder across far southern Kansas for now. Also, with the
medium range models trending slower with the arrival of widespread
precipitation chances, have opted to lower PoPs for Saturday night.
.LONG TERM...(Sunday through Wednesday)
Issued at 250 AM CDT Thu May 12 2016
Sunday through the middle of the workweek looks to be cloudy with
below normal temperatures continuing. Little changes have been
made with the potential for showers and thunderstorms as the
medium range models continue to show upper-level energy lifting
out of the central/southern Rockies towards the end of the
weekend. However, the medium range models continue to diverge in
regards to the timing and placement of potential widespread
showers and thunderstorms.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1135 PM CDT Wed May 11 2016
Aviation concerns are expected to remain minimal through the next
24 hours.
Water vapor imagery shows an upper wave lifting across west-
central KS. This feature is generating some mid level clouds along
with some sprinkles. Confidence is high that VFR conditions will
remain in place tonight. By sunrise...clear skies should be in
place area wide. Northwest/north winds will come around to the
west and southwest by the early evening hours Thu.
Lawson
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 77 52 80 48 / 10 0 30 30
Hutchinson 77 52 80 46 / 10 0 40 20
Newton 75 51 79 45 / 10 0 30 30
ElDorado 75 51 79 47 / 10 0 30 30
Winfield-KWLD 77 52 80 49 / 10 0 20 40
Russell 76 51 79 42 / 0 0 20 10
Great Bend 77 52 79 43 / 0 0 20 10
Salina 77 51 79 43 / 0 0 30 10
McPherson 76 50 79 43 / 0 0 40 20
Coffeyville 77 51 79 49 / 10 0 10 40
Chanute 76 51 79 47 / 10 0 20 40
Iola 75 50 78 47 / 0 0 20 40
Parsons-KPPF 76 51 79 48 / 10 0 20 40
&&
.ICT Watches/Warnings/Advisories...
None.
&&
$$
SYNOPSIS...JMR
SHORT TERM...JMR
LONG TERM...JMR
AVIATION...RBL
Area Forecast Discussion
National Weather Service Goodland KS
222 AM MDT THU MAY 12 2016
.SHORT TERM...(This afternoon through Tonight)
Issued at 1119 AM MDT Wed May 11 2016
17Z water vapor imagery and RAP analysis indicated trough in place
across northern plains, with clear closed circulation over North
Dakota. Of more importance to the Goodland CWA is the next short
wave trough moving over the four corners around the base of large
scale trough. With afternoon destabilization and period of large
scale ascent ahead of this trough, expect showers and
thunderstorms to develop over portions of Colorado and drift to
the east/southeast across the area. Overall instability fields are
limited, so aside from precip threat expect little overall impact.
Temps may dip down into the 30s in a few locations, but do not
expect any widespread frost or freeze conditions.
.LONG TERM...(Sunday through Wednesday)
Issued at 220 AM MDT Thu May 12 2016
For the long term period the GFS and European are in good agreement
Sunday with the placement and track of the closed low pressure
system in the Pacific northwest, as well as the ridge sitting over
the CWA. Come Monday, there are some major differences on the track
of the low. This poses a problem, especially with the potential for
severe weather. The GFS has a much more amplified trough, which has
been the case the last few nights, and the European has a much less
amplified trough that is much more north. With the trough moving in,
even with the differences between the models, there is a plethora of
moisture being pulled up from the Gulf of Mexico that will bring
chances for precipitation to the region Sunday onward. As for the
severe weather potential, Monday is looking like it could be a good
contender. The GFS has CAPE values up to 2200 J/kg around 00Z
Tuesday, bulk shear up to 60 kts, 700 mb open and closed shortwaves
and even DCAPE values reaching 800 J/kg over areas. All of those are
good indicators for potential severe weather but at this time the
certainty that the GFS will be the model that is true to reality is
hard to say, especially since the European is completely different
and temperatures are a little cool. So, as of right now will be
keeping showers as the main precipitation type but having chances
for thunderstorms Monday.
The remainder of the extended period continues to have chances for
precipitation. Wednesday may have a greater potential for
thunderstorms with a closed low moving over Nebraska. Temperatures
are expected to increase from the 50s and 60s Sunday through Tuesday
to the 70s Wednesday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1138 PM MDT Wed May 11 2016
VFR conditions are expected for the TAFs. light westerly winds are
expected for the period. during the evening the winds will turn to
the south.
&&
.GLD Watches/Warnings/Advisories...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...CLT
AVIATION...JTL
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
315 AM CDT THU MAY 12 2016
.SHORT TERM...(Today and Tonight)
Issued at 310 AM CDT THU MAY 12 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...(Friday through Wednesday)
Issued at 310 AM CDT THU MAY 12 2016
On Friday, surface high pressure will have moved southeast of the
area as an area of low pressure located in central Nebraska begins
to move towards northeast Kansas. As this cold frontal boundary
passes, showers and thunderstorms are expected to develop. While
moisture is limited ahead of this surface front, a sharp gradient of
instability and 0-6 km shear of 40-50 kts may allow for some
stronger to severe storms to develop, mainly in east central Kansas.
Soundings indicate storms will be elevated with steep lapse rates
near the surface making strong winds and hail the main threats
Friday. By late Friday evening, any storms will be southeast of the
forecast area and cold air will begin to usher in behind the front.
Highs drop significantly on Saturday into the upper 50s and low 60s.
There is a small chance for showers early morning Saturday as a very
subtle wave passes over the area.
From here, the only dry time for the rest of the period looks to be
Saturday afternoon though Sunday morning. Models still do not have
a great handle on the overall pattern for next week, but it appears
that an upper level low over the northwest CONUS will be present
with waves ejecting over the central US. The best chances for
precipitation will be Monday and Tuesday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday Night)
Issued at 1129 PM CDT WED MAY 11 2016
VFR conditions should prevail due to mid clouds preventing good
radiational cooling and northwest winds advecting dry air into the
region.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Johnson
LONG TERM...Heller
AVIATION...Wolters
Area Forecast Discussion
National Weather Service Dodge City KS
312 AM CDT THU MAY 12 2016
...UPDATE TO LONG TERM...
.SHORT TERM...(Today and tonight)
Issued at 1230 AM CDT Thu May 12 2016
Drier conditions are likely today and Thursday night as short range
models indicate an upper level shortwave trough lifting northeast
out of the Northern Plains into the Upper Midwest during the period.
This will give way to a northwesterly flow aloft across the Western
High Plains while surface high pressure spreads eastward across the
region. This and a minimal amount of instabilty will limit precip
chances through Thursday night. Mild temperatures can be expected
today as surface high pressure across Colorado sinks southeast
into the Texas Panhandle, returning a west to southwesterly
downslope flow to western Kansas this afternoon. Considering there
will be little change to the overall air mass, look for highs back
up into the 70s(F) this afternoon. Slightly warmer low temperatures
are likely Thursday night as the surface high pushes further to
the southeast setting up a south to southwesterly flow to western
Kansas. Lows are expected to drop only into the 50s(F) as warmer
air is drawn northward into the region.
.LONG TERM...(Friday through Wednesday)
Issued at 308 AM CDT Thu May 12 2016
Precip chances pick up a little late Friday as medium range models
indicate an upper level shortwave trough cycling southeast across
the Upper Midwest, sending an attendant cold front southward
across the Central Plains. Showers and thunderstorms will be
possible Friday afternoon and evening as the frontal boundary
encounters increased moisture in central and eastern portions of
southwest Kansas. However, mid range model soundings show limited
instability while dynamics aloft remain less than favorable with a
strong jet staying well off to our northeast in the Upper Midwest.
This will limit the severe potential for any developing storms.
Precip chances will continue into the weekend as a westerly flow
aloft sets up across the high plains while an east to southeasterly
upslope flow develops across western Kansas on the back side of a
departing surface high.
A brief warming trend will continue Friday as a low level
southwesterly flow enhances warm air advection into southwest and
central Kansas ahead of an advancing cold front. The GFS and ECMWF
show H85 temperatures warming into the mid to upper teens(C)
across central Kansas to near, if not a little above 20C in
extreme southwest Kansas. Should see highs well up into the 70s(F)
across west central Kansas to the lower to mid 80s(F) in south
central Kansas where the front isn`t expected to push through
until late afternoon. Much cooler temperatures can be expected
Saturday as colder air surges southward into western Kansas in
wake of the strong cold frontal passage. The unseasonably cool
temperatures will persist through the weekend.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1207 AM CDT Thu May 12 2016
Isolated showers will continue to slowly dissipate overnight while
drifting slowly east across western and central Kansas. Otherwise,
VFR conditions are expected at all TAF sites through late Thursday
afternoon. Light and variable winds will persist through the period
as a broad surface high moves out of the Colorado Rockies into the
Western High Plains.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 75 52 80 45 / 10 10 20 20
GCK 73 50 80 44 / 0 0 10 10
EHA 73 50 82 46 / 10 0 10 20
LBL 75 50 82 47 / 10 0 20 20
HYS 73 51 79 42 / 0 0 10 10
P28 78 53 82 49 / 10 10 30 30
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...JJohnson
LONG TERM...JJohnson
AVIATION...JJohnson
Area Forecast Discussion
National Weather Service Goodland KS
1142 PM MDT WED MAY 11 2016
.SHORT TERM...(This afternoon through Tonight)
Issued at 1119 AM MDT Wed May 11 2016
17Z water vapor imagery and RAP analysis indicated trough in place
across northern plains, with clear closed circulation over North
Dakota. Of more importance to the Goodland CWA is the next short
wave trough moving over the four corners around the base of large
scale trough. With afternoon destabilization and period of large
scale ascent ahead of this trough, expect showers and
thunderstorms to develop over portions of Colorado and drift to
the east/southeast across the area. Overall instability fields are
limited, so aside from precip threat expect little overall impact.
Temps may dip down into the 30s in a few locations, but do not
expect any widespread frost or freeze conditions.
.LONG TERM...(Thursday through Wednesday)
Issued at 232 PM MDT Wed May 11 2016
Thursday-Friday: Upper level ridging will build across the western
US with northwest flow developing across the northern plains. The
main upper level jet and mid level storm track will remain well
north of our cwa during these periods supporting dry conditions
through at least Friday afternoon. Temperatures will trend towards
seasonal to slightly above normal values with lee trough
redevelopment in eastern Colorado and southerly flow through the
boundary layer. Highs will generally be in the 70s, with a larger
spread on Friday as a cold front approaches from the north. Ahead of
this front stronger WAA may support highs around 80F.
Friday night-Wednesday: A cold front will push south through the
region and stall south of our region, with below normal temperatures
through these periods and increasing precip chances. Models are
showing the potential for a few showers in our northeast late Friday
night as a band of elevated frontogenesis moves through the area
behind the cold front. Deep moist advection is limited Friday night,
and this could limit potential coverage.
An upper level trough building over the west will eventually result
in SW flow along with southerly return from from the Gulf of Mexico
by Saturday night. This will set the stage for several possible
periods of showers and thunderstorms with a series of quick moving
shortwave troughs and possible closed h7/h5 upper lows moving over
our CWA. The strongest precip signal continues to be on
Monday/Monday night.
Despite the good model overlap in QPF the evolution of the upper
level pattern and impact on the surface pattern is still in
question with less run to run consistency beyond Sunday. Most
guidance is favoring a stationary front remaining outside (west
and south) of our cwa. On the other hand, the operational GFS is
showing this front lifting north as a warm front Monday and the
potential for a severe weather outbreak. I was comfortable with
PoPs inherited by latest blend and cooling temperature trend
considering the ensemble support and model consensus. I am just
not sold on the idea of more than just showers with embedded
thunderstorms or an elevated severe threat at this range.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1138 PM MDT Wed May 11 2016
VFR conditions are expected for the TAFs. light westerly winds are
expected for the period. during the evening the winds will turn to
the south.
&&
.GLD Watches/Warnings/Advisories...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...DR
AVIATION...JTL
AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
626 AM CDT THU MAY 12 2016
.UPDATE...
Issued at 626 AM CDT Thu May 12 2016
We adjusted sky cover to reflect the southward expansion of low
clouds (stratus) into southwest ND observed on satellite the last
several hours with this update. Otherwise, the going forecast was
largely on track. We will let the frost advisory over western ND
play out until its scheduled 13 UTC (8 am CDT) expiration time,
but only localized areas may have gotten cold enough for frost as
cloud cover and winds held temperatures up a bit overnight. In
fact, the wind may have prevented much frost formation even in
places where temperatures have approached 32 F.
&&
.SHORT TERM...(Today and tonight)
Issued at 329 AM CDT Thu May 12 2016
The closed upper level low (with a coincident surface low) had lifted
northeast into southern Manitoba...and gusty northwest winds
continued bringing cold air into North Dakota. Temperatures were in
the mid 30s over the western third of North Dakota where the current
frost advisory is valid. Thus the advisory appears to be verifying.
This stacked system is forecast to move east into Ontario, and then
dumbbell around the Ontario/Manitoba area through the weekend. This
will result in a cool cyclonic northwesterly flow across the state.
A significant shortwave in the upper flow swings down across North
Dakota tonight...merging with a fast-moving shortwave emanating from
another closed low that is currently over British Columbia. This
will set up a tight baroclinic zone with a strong frontogenetic band
setting up across eastern Montana and western/southern North Dakota.
This will result in a band of rain showers (mixed with snow showers
late tonight) across southern North Dakota.
Widespread frost is expected tonight with a reinforcement of cold
air pushing south across the state. Freezing temperatures expected
across the north may result in a freeze warning needed. Will let the
day shift issue frost/freeze headlines so as to not have two
separate frost advisories out that might cause confusion to users.
.LONG TERM...(Friday through Wednesday)
Issued at 329 AM CDT Thu May 12 2016
Main highlight in the long term will be persistent frost advisories
or freeze warnings across western and central North Dakota each
night and early morning through Sunday morning. Cyclonic northwest
flow will keep the region cooler than normal along with periodic
chances for showers.
Dry Friday through Friday night with cooler air arriving behind the
departing upper shortwave from Thursday night. A widespread freeze
warning still looks likely Friday night into early Saturday morning.
For Saturday night, still looking like a possible freeze warning in
the southwest with a frost advisory elsewhere.
For Sunday through Thursday, it will be dry Sunday then
slight chances for showers return Monday through Wednesday as the
upper flow becomes cyclonic through Thursday. Afternoon high
temperatures should be in the low to mid 60s during this time
period. Overnight lows mainly from the mid 30s to mid 40s...and
frost advisories may be needed.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 626 AM CDT Thu May 12 2016
Widespread MVFR ceilings will impact all but far southwestern ND
through about 15 UTC. Conditions will improve from southwest to
northeast today, with VFR conditions returning to KDIK around 15
UTC, KISN and KBIS by 18 UTC, and KMOT and KJMS by early to mid
afternoon. Gusty northwest winds will continue today, especially
in central ND, thanks to low pressure in Ontario.
&&
.BIS Watches/Warnings/Advisories...
Frost Advisory until 8 AM CDT /7 AM MDT/ this morning for NDZ001-
002-009-010-017-018-031>033-040-041-043-044.
&&
$$
UPDATE...CJS
SHORT TERM...JV
LONG TERM...JV
AVIATION...CJS
Area Forecast Discussion
National Weather Service Bismarck ND
331 AM CDT THU MAY 12 2016
.SHORT TERM...(Today and tonight)
Issued at 329 AM CDT Thu May 12 2016
The closed upper level low (with a coincident surface low) had lifted
northeast into southern Manitoba...and gusty northwest winds
continued bringing cold air into North Dakota. Temperatures were in
the mid 30s over the western third of North Dakota where the current
frost advisory is valid. Thus the advisory appears to be verifying.
This stacked system is forecast to move east into Ontario, and then
dumbbell around the Ontario/Manitoba area through the weekend. This
will result in a cool cyclonic northwesterly flow across the state.
A significant shortwave in the upper flow swings down across North
Dakota tonight...merging with a fast-moving shortwave emanating from
another closed low that is currently over British Columbia. This
will set up a tight baroclinic zone with a strong frontogenetic band
setting up across eastern Montana and western/southern North Dakota.
This will result in a band of rain showers (mixed with snow showers
late tonight) across southern North Dakota.
Widespread frost is expected tonight with a reinforcement of cold
air pushing south across the state. Freezing temperatures expected
across the north may result in a freeze warning needed. Will let the
day shift issue frost/freeze headlines so as to not have two
separate frost advisories out that might cause confusion to users.
.LONG TERM...(Friday through Wednesday)
Issued at 329 AM CDT Thu May 12 2016
Main highlight in the long term will be persistent frost advisories
or freeze warnings across western and central North Dakota each
night and early morning through Sunday morning. Cyclonic northwest
flow will keep the region cooler than normal along with periodic
chances for showers.
Dry Friday through Friday night with cooler air arriving behind the
departing upper shortwave from Thursday night. A widespread freeze
warning still looks likely Friday night into early Saturday morning.
For Saturday night, still looking like a possible freeze warning in
the southwest with a frost advisory elsewhere.
For Sunday through Thursday, it will be dry Sunday then
slight chances for showers return Monday through Wednesday as the
upper flow becomes cyclonic through Thursday. Afternoon high
temperatures should be in the low to mid 60s during this time
period. Overnight lows mainly from the mid 30s to mid 40s...and
frost advisories may be needed.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1230 AM CDT Thu May 12 2016
Surface low pressure will continue to produce gusty northwest
winds across southwest North Dakota. Low vfr to high mvfr
conditions will prevail at all TAF sites due to ceilings through the
overnight hours. Expect kdik and kisn to become vfr around 14z with
vfr at kmot/kbis around 16z-18z and aft 18z at kjms.
&&
.BIS Watches/Warnings/Advisories...
Frost Advisory until 8 AM CDT /7 AM MDT/ this morning for NDZ001-
002-009-010-017-018-031>033-040-041-043-044.
&&
$$
SHORT TERM...JV
LONG TERM...JV
AVIATION...JV
Area Forecast Discussion
National Weather Service Grand Forks ND
324 AM CDT THU MAY 12 2016
.SHORT TERM...(Today through Friday)
Issued at 307 AM CDT Thu May 12 2016
A much cooler pattern setting up. Upper level low is now near
Winnipeg with sfc low in same location just north of Winnipeg.
wraparound showers have been few and far between into north
central North Dakota. Wraparound stratocu covers much of the
North Dakota except the southeast and into much of northwestern
and west central Minnesota also in the dry slot. As sfc/upr low
slowly advance northeast the stratocu clouds will spread east
today as will increasing westerly winds. As for
precipitation, will maintain some very low pops for a light
shower or sprinkle shower in the far nrn RRV into nw MN closer to
colder air aloft but overall wraparound precip is quite minimal.
Clouds likely to hold in most areas tonight. As for tonight
temps, clouds should prevent a big fall but force of cold air
alone should send temps down to near freezing in far nrn fcst
area. Did include patchy frost in far nw areas though with clouds
and wind an actual white frost is not anticipated but temps low
enough for some impacts possibly. No headlines issued but
something to continue to look at. Temps below freezing even with
clouds and wind would pose more of a problem for sensitive
plants/crops and if temps do look like they may fall to around 30
then headlines may be necessary for late tonight.
Also tonight, a short wave will move east-southeast through
southern SD with some light rain chances along the SD border late
tonight.
Main colder air surge to arrive Friday as a vort max rotates back
south around the departing upper low and moves into the RRV by 12z
Friday. This will drop south and colder air will move in gusty
north- northwest winds. High temps on friday in the 40s. Could be
a few light showers or sprinkles but that is about it.
.LONG TERM...(Friday night through Wednesday)
Issued at 307 AM CDT Thu May 12 2016
Issue Friday night will be temps. If any night will see
widespread sub 32 degree readings it would be the 07z to 13z
Saturday period. 850 mb temps bottom out in the -8 to -11C range.
Not an ideal radiational cooling situation as clouds may hold on
ne ND into nrn MN with best chc of clearing sw fcst area. But
even with clouds and some wind lows in the 28-32 range seem quite
likely. Will continue to highlight this in social media products
and HWO.
Otherwise Saturday will likely see a mix of cloud and sun. A few
models spit out light precip Saturday as a weak short wave drops
south. Did leave in a low pop for mainly ne ND and nw MN. Did drop
any pops Saturday night per coord with MPX. Depending on sky
cover, lows late Saturday night could be around freezing in
eastern fcst area.
Sunday-Wednesday...Eastern North America upper trough will break
down early in the period although the GFS remains more persistent
in maintaining somewhat cooler cyclonic flow across the region.
Overall expect a split flow pattern to develop with temps fairly
seasonable to slightly below average. Given differences in the
upper air pattern among models confidence in precip chances is low
but have maintained some low pops for early next week. Currently
not expecting signficant precipitation during this period.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1121 PM CDT Wed May 11 2016
DVL has gone MVFR and will need to watch for potential for upper
end of IFR range as CIGS are dropping a bit quicker than initially
advertised. Other sites should be VFR through the night with
TVF/GFK/BJI having potential for MVFR near sunrise (FAR expected
to stay VFR through TAF periods). CIGS will begin to improve
tomorrow afternoon as wind speeds pick up and low pressure system
begins to move into Ontario.
&&
.FGF Watches/Warnings/Advisories...
ND...None.
MN...None.
&&
$$
SHORT TERM...Riddle
LONG TERM...Makowski/Riddle
AVIATION...Speicher
Area Forecast Discussion
National Weather Service Bismarck ND
1231 AM CDT THU MAY 12 2016
.UPDATE...
Issued at 1230 AM CDT Thu May 12 2016
Cold advection continues to push into the state with gusty northwest
winds. Frost advisory looking valid with some areas in the northwest
in the mid to upper 30s. Clouds and wind should keep temperatures
from falling below freezing over a large area.
UPDATE Issued at 944 PM CDT Wed May 11 2016
Winds continue to diminish across the west but will remain breezy
which should at least keep the minimum temperatures from
falling into the 20s. So the frost advisory looking good
especially as Crosby now at 37 degrees.
UPDATE Issued at 649 PM CDT Wed May 11 2016
The trend has been for winds to slowly decrease and the wind
advisory will be allowed to expire at 7 pm CDT. Otherwise the
upper low continues to meander around southwest Manitoba. Still
expect gradual clearing across the west later tonight and the
frost advisory will begin after 4 am CDT. The best chance for
showers this evening remains north central.
&&
.SHORT TERM...(This evening through Thursday)
Issued at 302 PM CDT Wed May 11 2016
For the near term, through late this afternoon is the ongoing wind
advisory in the southwest. This remains on track with sustained
northwest winds between 25kt and 30kt with gusts to 40kt. Current
advisory remains in good standing and no changes needed.
The latest water vapor imagery details a closed mid/upper level low
circulating over north central North Dakota. This low is forecast to
eject into Manitoba tonight, and then dumbbell around Ontario over
the weekend. The net result will be a dominant northwest flow into
North Dakota with periodic mid/upper level shortwaves rotating
around the low and sliding across western and central North Dakota
resulting in cooler temperatures along with periodic chances for
showers.
Visible satellite imagery and surface observations reveal a wide
swath of strato-cumulus clouds associated with a low level
cold/moist pocket of air underneath the large upper low. The
experimental HRRR shows another round of clouds shift from
northwest to southeast tonight associated with an 850mb cold
pocket nosing into western and central North Dakota. These clouds
will be most notable in northern and central North Dakota, with
clouds gradually thinning in western North Dakota late tonight.
For the short term period tonight through Thursday, scattered rain
showers across north central North Dakota will slowly shift into the
Turtle Mountains tonight in association with the movement of the
upper low. An isolated shower southwest and south central possible
until sunset this evening.
The main weather impact comes late tonight into early Thursday
morning, as a partly cloudy sky develops and winds slowly diminish
west. This leads to temperatures falling into the mid 30s. A
frost advisory has been issued across the west late tonight into
early Thursday morning. Too many clouds will remain across the
central North Dakota for much of an impact.
On Thursday, a dry day is expected with partly to mostly cloudy
conditions. Breezy northwest winds of 15 to 25 mph will continue
with highs mostly in the 50s.
.LONG TERM...(Thursday night through Wednesday)
Issued at 302 PM CDT Wed May 11 2016
Main highlight in the long term will be persistent frost advisories
or freeze warnings across western and central North Dakota each
night and early morning through Sunday morning. Cyclonic northwest
flow will keep the region cooler than normal along with periodic
chances for showers.
For Thursday night, a mid/upper level shortwave (700mb- 500mb) will
rotate around the aforementioned upper low and shift south into
western North Dakota Thursday evening. A surface low pressure will
slide from southeast Montana into western South Dakota. Weak low
level convergence will set up in southwest North Dakota Thursday
night. The approach of the shortwave and a 90kt 300mb jet will
provide enough ascent for a chance of showers southwest and far
southern North Dakota Thursday night. A freeze warning appears
likely for most of western and central North Dakota with the
exception for the far southwest and into south central North Dakota
where a frost advisory seems more likely at this time.
Dry Friday through Friday night with cooler air arriving behind the
departing upper shortwave from Thursday. A widespread freeze warning
looks likely Friday night into early Saturday morning.
For Saturday, another shortwave and jet streak shift across central
North Dakota for a chance of rain in the afternoon. Behind the
shortwave Saturday night, a possible freeze warning in the southwest
with a frost advisory elsewhere remains feasible.
For Sunday through Wednesday, it will be dry Sunday then chances for
showers return Monday through Wednesday as the upper flow remains
loosely cyclonic Monday through Wednesday. Afternoon high
temperatures rebound into the lower and mid 60s Monday through
Wednesday. Possible frost advisory in the southwest Monday and
Tuesday mornings, but coverage appears minimal at this time.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1230 AM CDT Thu May 12 2016
Surface low pressure will continue to produce gusty northwest
winds across southwest North Dakota. Low vfr to high mvfr
conditions will prevail at all TAF sites due to ceilings through the
overnight hours. Expect kdik and kisn to become vfr around 14z with
vfr at kmot/kbis around 16z-18z and aft 18z at kjms.
&&
.BIS Watches/Warnings/Advisories...
Frost Advisory from 4 AM CDT /3 AM MDT/ to 8 AM CDT /7 AM MDT/
this morning for NDZ001-002-009-010-017-018-031>033-040-041-043-
044.
&&
$$
UPDATE...JV
SHORT TERM...KS
LONG TERM...KS
AVIATION...JV
Area Forecast Discussion
National Weather Service Phoenix AZ
930 PM MST FRI MAY 13 2016
.SYNOPSIS...
High pressure over the region is starting to weaken and signals a
change to slighly cooler temperatures and more breezy conditions for
the weekend. An approaching low pressure system will slowly drop down
into Arizona by Tuesday and help keep temperatures at or below normal
for a few days and even provide a chance for thunderstorms Sunday
through Tuesday.
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...
High pressure ridge axis is aligned over eastern Arizona right now.
Water vapor imagery shows an area of high clouds and upper level
moisture moving towards the northeast over the eastern part of the
state. Another surge of high level moisture is moving across southern
California. IR satellite indicates a closed low pressure system off
the northwest California coast.
The high pressure ridge is already beginning to weaken and slip
slightly towards the east. Pressures are expected to continue to drop
slowly through Sunday evening as the Pacific low pressure moves into
the northwest U.S. and exerts more influence over the western U.S.
For Arizona and southern California gradient will increase and thus
increase winds across the area as well as pull down some cooler air.
The breezy conditions will extend down to the surface leading to some
afternoon winds across Arizona both Saturday and Sunday. This should
be a dry system, not bringing any significant chance for rain at
least across our CWA. The low pressure system will stay entrenched
over the region for several more days and will produce at least one
short wave rotating around the low pressure. This will move into
Arizona late Monday into Tuesday. At the same time the low pressure
is progged to deepen and push south, increasing its influence over
the desert southwest. By Tuesday evening and Wednesday morning it
will even bring a chance for some rain and possibly thunderstorms---
at least over higher terrain. The low will finally pull out of the
region and weaken by Thursday but will leave us in zonal flow and
thus help keep us from getting under another high pressure ridge
pattern and helping hold temps down just a bit.
.PREVIOUS DISCUSSION...
Return flow around a ridge to our east predominates this afternoon,
which has helped to produce well-above normal temperatures but short
of records. Meanwhile, moisture continues to lift northward out of
Sonora ahead an anomalous trough evident in the upper-level
streamlines across the Gulf of California. Little impact from this
system is expected today or tonight. However, global models and CAMs
continue to suggest that the residual moisture will promote the
development of isolated convection Saturday. PoPs were consequently
increased (but remain below 10 percent) for Saturday morning and
afternoon, particularly from Phoenix eastward and across the higher
terrain. The increase in low- level moisture (mixing ratios up to
around 6 g/kg) and cloudiness will have an effect on temperatures and
highs were lowered roughly one degree from the previous forecast.
Nevertheless, temperatures will remain several degrees above average.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...SOUTHEAST
CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
A couple of weak weather disturbance ahead of an approaching low
pressure system will create some cloudiness above FL100 with possibly
some isolated virga the rest of the afternoon into Saturday. Areas
east of the Lower Colorado River Valley are most likely to be
affected (more so southeast AZ). Otherwise, expect familiar warm
season diurnal wind patterns (stronger tomorrow afternoon).
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
Monday through Friday...
A low pressure system centered over Idaho on Monday will dig
southward becoming centered over northwest AZ by Tuesday afternoon.
This will lead to a slight chance of thunderstorms Tuesday/Tuesday
night. The low will weaken Wednesday and move out Thursday. Breezy to
windy conditions develop Friday (mainly near and west of the Lower
Colorado River Valley) as another system approaches. Minimum
humidities will generally be in the 10-15 percent range on the lower
deserts (closer to 15% on Tuesday; closer 10% Thu-Fri). Overnight
recovery will be good early in the week then slowly decline.
&&
.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
Aviation...AJ
Fire Weather...AJ
[top]
Area Forecast Discussion
National Weather Service Flagstaff AZ
345 PM MST FRI MAY 13 2016
.SYNOPSIS...A Low pressure system off the west coast will bring
increasing southwest winds, cooling temperatures, and slight chances
for showers and thunderstorms this weekend. From Monday through
Thursday, the low pressure system will cross the state causing
better chances for showers and thunderstorms and near to slightly
below average temperatures.
&&
.DISCUSSION...High pressure over Arizona peaked today and will start
to move east tonight as a low pressure system approaches the West
Coast. Increasing mid and high level moisture from the south brought
a few light showers to southern Apache County this afternoon.
On Saturday, the high pressure will continue to move east as the low
off the West Coast moves eastward. This will bring a cooling trend,
increasing southwest winds, and increasing moisture. Isolated high
based showers and thunderstorms will be possible over higher terrain
-primarily along and north of the Mogollon Rim on Saturday. By
Sunday, the approaching low pressure system will bring strong
southwest winds across much of northern Arizona. The strongest winds
are expected across central and southern Navajo and Apache counties,
where wind gusts exceeding 40 mph are possible.
From Monday through Thursday: The upper level low will move
southward on Monday before crossing Arizona on Tuesday and
Wednesday. This will lead to increasing chances for precipitation
and near to slightly below average daytime temperatures. On Monday,
there are slight chances for showers and thunderstorms, primarily
along and north of Interstate 40. On Tuesday and Wednesday, better
chances for showers are expected across all of northern Arizona as
the low passes over the state. By Thursday, the low is expected move
eastward into New Mexico with lingering showers and thunderstorms
along the Arizona and New Mexico border.
&&
.AVIATION...For the 00Z package...Expect SKC-SCT skies through 18Z
Saturday, though east of KSOW may be the exception with a slight
chance of showers tonight. Slight chance for showers spread to much
of northern Arizona after 18Z Saturday. Light winds overnight will
turn southwesterly and breezy after 18Z Saturday as well. Aviation
discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Southwest winds will increase on Saturday as a
trough builds into the southwest United States, along with the
threat of isolated high-based afternoon thunderstorms. Generally dry
conditions are forecast for Sunday, though southwest winds will
strengthen that day leading to near critical fire weather
conditions.
Monday through Wednesday...Increasing chances of afternoon
thunderstorms along with cooler daytime temperatures are expected as
low pressure settles into the region.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...MAS
AVIATION...KD
FIRE WEATHER...KD
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Phoenix AZ
327 PM MST FRI MAY 13 2016
.UPDATE...
Updated Aviation and Fire Weather sections.
&&
.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...
Return flow around a ridge to our east predominates this afternoon,
which has helped to produce well-above normal temperatures but short
of records. Meanwhile, moisture continues to lift northward out of
Sonora ahead an anomalous trough evident in the upper-level
streamlines across the Gulf of California. Little impact from this
system is expected today or tonight. However, global models and CAMs
continue to suggest that the residual moisture will promote the
development of isolated convection Saturday. PoPs were consequently
increased (but remain below 10 percent) for Saturday morning and
afternoon, particularly from Phoenix eastward and across the higher
terrain. The increase in low- level moisture (mixing ratios up to
around 6 g/kg) and cloudiness will have an effect on temperatures and
highs were lowered roughly one degree from the previous forecast.
Nevertheless, temperatures will remain several degrees above average.
&&
.PREVIOUS DISCUSSION...
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...
A couple of weak weather disturbance ahead of an approaching low
pressure system will create some cloudiness above FL100 with possibly
some isolated virga the rest of the afternoon into Saturday. Areas
east of the Lower Colorado River Valley are most likely to be
affected (more so southeast AZ). Otherwise, expect familiar warm
season diurnal wind patterns (stronger tomorrow afternoon).
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
Monday through Friday...
A low pressure system centered over Idaho on Monday will dig
southward becoming centered over northwest AZ by Tuesday afternoon.
This will lead to a slight chance of thunderstorms Tuesday/Tuesday
night. The low will weaken Wednesday and move out Thursday. Breezy to
windy conditions develop Friday (mainly near and west of the Lower
Colorado River Valley) as another system approaches. Minimum
humidities will generally be in the 10-15 percent range on the lower
deserts (closer to 15% on Tuesday; closer 10% Thu-Fri). Overnight
recovery will be good early in the week then slowly decline.
&&
.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
[top]
Area Forecast Discussion
National Weather Service Tucson AZ
245 PM MST FRI MAY 13 2016
.SYNOPSIS...
Strong high pressure aloft will bring well above average
temperatures Saturday. There is also enough moisture for a slight
chance of showers and thunderstorms from Tucson eastward Saturday
afternoon. A storm system moving north of the area will then bring
gusty winds Sunday followed by cooler temperatures early next week.
&&
.DISCUSSION...Partly cloudy to mostly cloudy skies across southeast
Arizona this afternoon as fairly thick cirriform clouds move
northeastward across the area. Some cumuloform clouds were also
noted across the White mountains and near the New Mexico border as
per visible satellite imagery. Have maintained a slight chance of
showers and thunderstorms thru this evening mainly near the
International border south-to-southeast of Tucson, and across far
eastern sections. Dry conditions are then expected late tonight into
Saturday morning.
Southwesterly flow aloft will prevail Saturday afternoon ahead of a
low pressure system moving eastward into the Pacific NW. 13/12Z Univ
of AZ WRF-NAM and WRF-GFS were quite similar with developing
showers/thunderstorms mainly near the Catalina/Rincon mountains near
Tucson early Saturday afternoon. These showers/thunderstorms are
then depicted to expand in coverage while moving newd across ern
sections Saturday afternoon and early Saturday evening. These
solutions are more similar to the 13/12Z ECMWF versus the drier GFS.
Thus, the official forecast depicts a slight chance of showers/tstms
from near the Tucson metro area eastward to the New Mexico border
Saturday afternoon/evening. Dry conditions are then expected
Saturday night-Monday night. However, a tight mid-level gradient
will translate into gusty southwest winds Sunday afternoon. Wind
advisory criteria may be achieved Sunday afternoon for locales
southeast of Tucson. Somewhat less wind will occur Monday.
GFS/ECMWF were similar with deepening an upper trough over the Great
Basin/Intermountain west/southwestern CONUS Tue-Wed. The ECMWF was
markedly more robust with liquid amounts versus the GFS. At any
rate, There is a chance of showers/tstms Tue afternoon/evening
mainly across the White mountains. Have included a slight chance of
showers/tstms for eastern sections Wednesday. A drying trend should
commence Wed night as the mid-level trough axis moves east of the
area. Still enough moisture for a slight chance of showers/tstms
across the White mountains Wed night-Thur. Dry conditions are then
expected to prevail Thur night-Fri under wly/swly flow aloft.
High temps Sat will be quite similar to temps achieved this
afternoon followed by about 5 degs or so of daily cooling Sun-Mon.
High temps Tue-Wed will be below normal, then a pronounced warming
trend is on tap Thur-Fri.
&&
.AVIATION...VALID THRU 15/00Z.
Expect isolated -TSRA/-SHRA near the Mexico and New Mexico border
thru 14/04Z otherwise sct-bkn clouds above 20k ft thru much of
tonight. After 14/19Z isold-sct -TSRA/-SHRA developing with sct to
locally bkn 10k ft clouds. Surface wind through 14/03Z will be
wly/nwly at 10-15 kts then becoming variable at less than 10 kts.
Wind becoming SW 9-16 kts Saturday afternoon. Aviation discussion
not updated for TAF ammendments.
&&
.FIRE WEATHER...Any convection that develops through this evening
should remain limited to the Mexico and New Mexico border. However
moisture will increase later tonight and Saturday enough to bring a
threat of showers and thunderstorms from the Tucson area eastward
Saturday afternoon and early evening. Any storms that develop
Saturday will move to the east-northeast.
A strong upper level trough will approach the region Sunday forcing
drier air over the area on gusty southwest winds. At this time it
looks like a significant portion of fire zones 151 and 152 will
reach critical fire weather conditions Sunday afternoon.
Therefore I have issued a Fire Weather Watch for the southern 2/3rds
of both zones for late Sunday morning into early Sunday evening.
Dry but cooler conditions will prevail Monday followed by a slight
chance of showers and thunderstorms Tuesday into Wednesday, mainly
north. Thursday and Friday will be warm and dry with less wind.
&&
.TWC Watches/Warnings/Advisories...
Fire Weather Watch from Sunday morning through Sunday evening
for AZZ151-152.
&&
$$
Discussion...Francis
Aviation/Fire Weather...Cerniglia
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Phoenix AZ
221 PM 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...
Return flow around a ridge to our east predominates this afternoon,
which has helped to produce well-above normal temperatures but short
of records. Meanwhile, moisture continues to lift northward out of
Sonora ahead an anomalous trough evident in the upper-level
streamlines across the Gulf of California. Little impact from this
system is expected today or tonight. However, global models and CAMs
continue to suggest that the residual moisture will promote the
development of isolated convection Saturday. PoPs were consequently
increased (but remain below 10 percent) for Saturday morning and
afternoon, particularly from Phoenix eastward and across the higher
terrain. The increase in low- level moisture (mixing ratios up to
around 6 g/kg) and cloudiness will have an effect on temperatures and
highs were lowered roughly one degree from the previous forecast.
Nevertheless, temperatures will remain several degrees above average.
&&
.PREVIOUS DISCUSSION...
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 Flagstaff AZ
945 AM MST FRI MAY 13 2016
.SYNOPSIS...High pressure over northern Arizona will lead to another
warm day, with high temperatures around 10 degrees above average.
Limited moisture will bring a slight chance of thunderstorms to the
White Mountains this afternoon. An approaching low pressure system
will cause increasing southwest winds, cooling temperatures, and
slight chances for showers and thunderstorms over higher terrain
over the weekend. From Monday through Thursday, the low pressure
system will cross the state causing better chances for showers and
thunderstorms and near to slight below normal temperatures.
&&
.DISCUSSION...Increasing mid and high level moisture from the south
today will bring a slight chance of high based showers and
thunderstorms to the White Mountains today. The leading edge of this
moisture is seen in the form of high clouds moving into southern
Arizona this morning. Will update the forecast for Northern Gila,
Eastern Mogollon Rim, and White Mountains today and this evening.
&&
.PREV DISCUSSION /425 AM MST/...For today: A ridge of high pressure
in place across northern Arizona will lead to the warmest
temperatures of the year so far. In general, high temperatures are
forecast to be around 10 degrees above normal. In addition, expect
mostly clear skies, dry weather and relatively light winds. An
exception to this may be in the White Mountains region where a
slight chance for high based showers and thunderstorms is forecast.
For the weekend: While Saturday is expected to be another warm
day, the upper level ridge axis shifts eastward with the approach
of a Pacific low pressure system. This will result in the
beginning of a slow cooling trend and increasing southwest winds.
In addition, enough low and mid level moisture may be drawn
northward into the region for isolated high based showers and
thunderstorms over higher terrain - primarily along and north of
the Mogollon Rim. By Sunday, the approaching low pressure system
is forecast to cause strong southwest winds across much of
northern Arizona. The strongest winds are expected across central
and southern Navajo and Apache counties, where wind gusts
exceeding 40 mph are possible.
From Monday through Thursday: The upper level low is forecast to
dive southward on Monday before crossing Arizona on Tuesday and
Wednesday. This will lead to increasing chances for precipitation
and near to slightly below normal daytime temperatures. On
Monday, slight chances for showers and thunderstorms are forecast,
primarily along and north of Interstate 40. On Tuesday and
Wednesday, better chances for showers are forecast across all of
northern Arizona as the low passes over the state. By Thursday,
The low is forecast to move eastward into New Mexico with
lingering showers and thunderstorms possible along the Arizona and
New Mexico border.
&&
.AVIATION...For the 18Z package...Expect VFR conditions
for the next 24 hours with occasional southwesterly breezes this
afternoon. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...A high pressure ridge will remain over the
area today with above normal high temperatures...followed by an
approaching low pressure trough on Saturday. Southwest winds will
increase on Saturday, along with the threat of isolated high based
afternoon thunderstorms.
Sunday through Tuesday...Low min Rh`s on Sunday and very windy
afternoon conditions will lead to near critical fire weather
conditions. Monday and Tuesday, increasing chances of afternoon
thunderstorms are expected as low pressure moves on by.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...MAS/RR
AVIATION...KD
FIRE WEATHER...TC
For Northern Arizona weather information visit
weather.gov/flagstaff
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
NWS WILMINGTON NC
328 AM EDT SAT MAY 14 2016
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA THIS EVENING WITH
PERHAPS SOME SPRINKLES ACROSS PORTIONS OF THE AREA. COOLER
TEMPERATURES AND DRIER AIR ARE EXPECTED BEHIND THIS FRONT FOR
SUNDAY AND MONDAY. TEMPERATURES WILL RISE BEGINNING TUESDAY WITH
GREATER CHANCE OF CLOUDS WITH SHOWERS AND THUNDERSTORMS RETURNING
MID AND LATE WEEK AS A FRONT DROPS SOUTH AND STALLS ACROSS THE
SOUTHEAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM SATURDAY...LAST TRACES OF RAIN HAVE ENDED AS A WEAK
COLD FRONT MOVES OFFSHORE, WITH CLEARING SKIES AND ONLY MINIMAL COLD
ADVECTION IN ITS WAKE. LOW LEVEL MOISTURE WILL ALSO TAKE ITS TIME
GETTING SCOURED OUT, LEAVING DEWPOINTS ELEVATED UP IN THE 60S
THROUGH THE MORNING HOURS. CLEARING SKIES, LIGHT WINDS AND AMPLE LOW
LEVEL MOISTURE WILL LEAD TO AT LEAST PATCHY FOG DEVELOPMENT THIS
MORNING.
WINDS WILL BACK TO THE SW THIS AFTERNOON IN ADVANCE OF THE NEXT,
STRONGER COLD FRONT. RESULTANT WARM ADVECTIVE PUSH WILL DRIVE
TEMPERATURES BACK UP INTO THE MID 80S THIS AFTERNOON. THERE MAY BE
JUST ENOUGH LOW LEVEL MOISTURE AND CONVERGENCE ALONG THE SEA BREEZE
FRONT TO POP A FEW SHOWERS THIS AFTERNOON...ESPECIALLY OVER OUR NC
COUNTIES CLOSEST IN VICINITY TO A PASSING UPPER VORT MAX. MOST
PLACES WILL STAY DRY THOUGH.
AN UNSEASONABLY STRONG COLD FRONT WILL MOVE ACROSS THE FORECAST AREA
OVERNIGHT, THIS TIME ACCOMPANIED BY SIGNIFICANTLY COOLER AND DRYER
AIR. EXPECT CLEAR SKIES AND LOWS IN THE MID TO UPPER 50S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...A DRY AND UNSEASONABLY COOL AIRMASS WILL
BUILD IN ON SUNDAY AND MONDAY, BRINGING US HIGHS ONLY IN THE MID TO
UPPER 70S FOR BOTH DAYS. A FRONT STALLED WELL TO THE SOUTH AT THE
BEGINNING OF THE SHORT TERM WILL KINK BACK NORTH MONDAY NIGHT.
RESULTING MODEST LIFT COMBINED WITH DEEP LAYER MOISTURE ADVECTION
WILL BRING OVERCAST SKIES AND THE CHANCE FOR LIGHT SHOWERS IN THE
PRE-DAWN HOURS OF TUESDAY MORNING.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 AM SATURDAY...HIGH PRESSURE SHIFTS FARTHER OFF THE
COAST ON TUESDAY ALLOWING FOR A WARM AND MOIST FLOW TO DEVELOP.
SFC DEWPOINT TEMPS WILL RETURN INTO THE 60S AND MOISTURE PROFILES
SHOW A RATHER DEEP COLUMN OF MOISTURE DEVELOPING THROUGH MID WEEK
IN A DEEP W-SW FLOW. MODELS CONTINUE TO SHOW MINOR SHORTWAVES
RIDING BY IN A GENERALLY FLATTER FLOW IN THE MID TO UPPER LEVELS.
THESE SHOULD ACT TO ENHANCE LOCALIZED PCP MAINLY ASSOCIATED WITH
SEA BREEZE ON TUESDAY. WILL ALSO SEE PLENTY OF CLOUDS STREAMING
ACROSS IN THE W-SW FLOW ALOFT. BY WEDNESDAY, A FRONT DROPS DOWN
FROM THE NORTH WHICH WILL ACT AS A FOCAL POINT FOR FURTHER LIFT
AND ADDITIONAL PCP. THIS BOUNDARY MAY HANG OVER OR JUST SOUTH OF
AREA AS HIGH PRESSURE BUILDS DOWN BEHIND IT AT THE SFC LEAVING A
NE-E FLOW FROM TUES NIGHT ONWARD. AT THE SAME TIME FLOW ALOFT
WILL REMAIN OUT OF THE S-SW OVERRUNNING THE N-NE FLOW AT THE SFC.
THIS SHOULD HELP TO PRODUCE CLOUDS AND PCP. THEN, BY FRIDAY, LOW
PRESSURE WILL EJECT OUT OF THE GULF COAST PRODUCING AN EVEN GREATER
CHC OF PCP AS IT MOVES UP THE SOUTHEAST COAST FRI INTO SATURDAY.
OVERALL EXPECT AN UNSETTLED WEEK BEGINNING ON TUESDAY WITH PLENTY
OF CLOUDS AND INCREASED RAIN CHANCES.
EXPECT LESSER DIURNAL SWINGS IN TEMPS WITH PLENTY OF CLOUDS AND
PCP. OVERNIGHT LOWS SHOULD BE CLOSER TO 60 AND DAYTIME HIGHS
SHOULD REACH INTO THE 80S TUES AND WED BEFORE COLD FRONT DROPS
SOUTH LATE WED...BRINGING TEMPS BELOW 80 MOST PLACES FOR THURS
AND FRI.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...POTENTIAL FOR MVFR/IFR OVERNIGHT DUE TO AREAS OF
FOG...ALONG WITH ISOLATED SHOWERS. OTHERWISE EXPECT VFR THROUGH
THE VALID TAF PERIOD.
LIGHT AND VARIABLE WINDS WILL PREVAIL OVERNIGHT WITH FEW/SCT/BKN AS
A COLD FRONT PUSHES THROUGH THE AREA. ANTICIPATE FOG DEVELOPMENT
LATE OVERNIGHT INTO THE EARLY MORNING HOURS, CREATING PERIODS OF
MVFR/IFR, MAINLY ALONG THE COAST. AFTER DAYBREAK, VFR WILL PREVAIL
WITH LIGHT WINDS BECOMING SOUTHWESTERLY AROUND 10 KTS WITH HIGHER
GUSTS POSSIBLE. INTO THE EVENING HOURS, GUSTS WILL SUBSIDE.
EXTENDED OUTLOOK...POTENTIAL FOR SHOWERS TUESDAY AND WEDNESDAY.
OTHERWISE, EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM SATURDAY...A WEAK COLD FRONT WILL MOVE ACROSS THE
WATERS EARLY THIS MORNING, TURNING WINDS TO THE NW, ALTHOUGH LACK
OF A CONVINCING COLD SURGE WILL KEEP SPEEDS IN THE 10 KT RANGE.
GRADIENT TIGHTENS AND WINDS BACK TO THE SW THIS AFTERNOON IN
ADVANCE OF THE NEXT, STRONGER, COLD FRONT, WHICH WILL MOVE
OFFSHORE OVERNIGHT. WINDS WILL VEER BACK TO THE NW IN ITS WAKE AND
INCREASE TO 15 TO 20 KTS. SEAS WILL BUILD TO 3 TO 5 FT IN
RESPONSE, WHICH WILL LIKELY PROMPT EXERCISE CAUTION HEADLINES FOR
THE OVERNIGHT PERIOD.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...COOL AND DRY HIGH PRESSURE WILL BUILD IN
ON SUNDAY AND INTO THE DAYLIGHT HOURS OF MONDAY IN THE WAKE OF AN
UNSEASONABLY STRONG COLD FRONT. THIS FRONT MAY KINK BACK NORTH TO
THE WATERS ON MONDAY NIGHT, BRINGING BACK THE CHANCE FOR SHOWERS.
WINDS AND SEAS MAY REMAIN ELEVATED EARLY ON SUNDAY FROM THE
PREVIOUS NIGHTS COLD SURGE, BUT WILL MODERATE FOR THE REMAINDER OF
THE SHORT TERM BY SUNDAY AFTERNOON.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 330 AM SATURDAY...HIGH PRESSURE WILL BE WELL OFF SHORE ON
TUESDAY WITH A FAIRLY LIGHT SOUTHERLY RETURN FLOW. THIS WILL KEEP
SEAS MAINLY 3 FT OR LESS TUES THROUGH WED. THE WINDS WILL VEER
THROUGH WED TO SW AND EVENTUALLY AROUND TO THE NE AS A COLD FRONT
DROPS THROUGH THE WATERS MAINLY AFTER MIDNIGHT. BY THURS WINDS
SHOULD BE NE ACROSS ALL LOCAL WATERS. A SLIGHT NE SURGE WILL PUSH
SEAS UP TO 3 TO 4 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...REK
SHORT TERM...REK
LONG TERM...RGZ
AVIATION...REK/SGL
Area Forecast Discussion
National Weather Service Raleigh NC
652 PM EDT FRI MAY 13 2016
.SYNOPSIS...A weak cold front will move off the coast late
tonight. A westerly flow will develop on Saturday before a much
stronger cold front moves across the area Saturday evening.
Chilly high pressure will build in from the west Saturday night
through Monday.
&&
.NEAR TERM /OVERNIGHT/...
As of 645 PM Friday...
As of 22Z, despite lingering low-level moisture and the presence of
an unstable airmass characterized by MLCAPE values of 500-1000 J/kg
along and east of Highway 1, DPVA attendant shortwave energy
progressing east across the region has largely shifted into eastern
NC late this afternoon, ushering a much drier /subsident/ airmass
aloft into the region from the west (per 22Z WV imagery and SPC
mesoanalysis data), at the same time a drier surface airmass
advances toward the coastal plain in the wake of a recent cold front
(located along/near the Carolina coast at 22Z). With the above in
mind, expect any remaining potential for convection to be confined
to Sampson county through ~00Z, with dry conditions elsewhere/
otherwise. Low temps will primarily be driven by the drier airmass
advecting slowly east/se across central NC tonight, with surface
dewpoints serving as the lowest possible temperature that could be
reached via radiational cooling overnight. Will indicate lows
ranging from the lower 50s northwest to lower 60s far southeast. Fog
and/or low stratus could develop in the far southeast coastal plain
after midnight where shallow low-level moisture is apt to linger the
longest while the surface front stalls in vicinity of the Carolina
coast and a drier airmass aloft progresses toward/offshore the coast
in the wake of the aforementioned shortwave. -Vincent
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
As of 355 PM Friday...
a strong northern stream shortwave trough will dive across the Ohio
Valley Saturday morning and off the Mid Atlantic coast on Saturday
evening. The associated cold front will move across central NC late
Saturday afternoon or early evening. A pronounced low-level westerly
flow will develop ahead of the front resulting in good mixing and a
relatively dry boundary layer. while the best forcing for ascent and
greater moisture associated with the shortwave will be located to
our north in the VA and points north, a shallow layer of moisture
and instability atop the mixed layer could generate a few showers
and possibly a thunderstorm. Given the very dry pre-frontal
environment, convective coverage should be quite limited. Behind the
front, even drier and cooler air will surge into the region.
Saturday should feature warm conditions with lots of morning
sunshine followed by some increasing clouds. Highs will range
between 80 and 85 degrees with a west to southwest wind at 10 to 15
mph with gusts of 20 to 25mph during the afternoon. Mainly clear
skies with chilly lows in the upper 40s to lower 50s are expected on
Saturday night. -Blaes
&&
.LONG TERM /Sunday through Friday/...
As of 245 PM Friday...
Sun-Mon: Cool and dry. The polar cold front will have pushed to our
south by Sun morning, with thicknesses plunging to 40-50 m below
normal as cool high pressure builds into and over the area from the
west. Expect mostly clear skies Sun/Sun night. Highs around 10 deg F
below normal, in the upper 60s to lower 70s. Lows 44-50. Forecast
soundings do suggest the potential for orographically enhanced
cirrus cloudiness Sun night into early Mon morning, given the fast
mid-high level WNW flow increasing with height, improving moisture
aloft, and shearing mid level vorticity passing just to our north.
Regardless of this occurring or not, we should still see increasing
clouds through the day Mon as the mid level flow flattens and
becomes WSW with a weak wave crossing the lower Miss Valley late in
the day. Thicknesses rebound slightly after the chilly start,
supporting highs Mon from around 70 to the mid 70s.
Mon night through Tue night: The aforementioned shortwave trough
will cross the Deep South and Southeast Mon night and Tue. As the
surface high shifts off the NC/VA coast, the frontal zone just to
our south will edge back northward as a warm front, and the
increasing overrunning flow drawing both Atlantic and Gulf moisture
up and over the frontal zone should lead to widespread rain
development over NC. Confidence in the details is low due to
differences in timing and placement of best rain chances on both the
deterministic models and on ensemble members (the GEFS
specifically). But overall, rain chances will be increasing Mon
night through Tue, to good chance or likely, with perhaps a relative
lull Tue night as the departure of the weak wave as well as a
corresponding strengthening surface low coincides with diurnal
cooling and stabilizing. The GFS and ECMWF both appear to be
converging on a solution in which the front moves into northern NC
but stalls or dips back southward further into the state late Tue
into Tue night, nudged southward by the circulation around the
offshore-moving surface low, with a cool stable pool over northern
NC. after lows Mon night in the mid 50s to around 60, highs Tue
should reflect a smaller diurnal change, with highs from around 70
NW to the mid-upper 70s S. Lows Tue night 58-65 with clouds and
drizzle.
Wed through Fri: Trends favor continued unsettled weather with below
normal temps, as an active fast mid level WSW flow persists. The
frontal zone initially stretching across northern NC is expected to
be pushed southward into southern NC by dense high pressure, which
itself is reinforced by confluent flow aloft around a positively
tilted mid level low from the Canadian Maritimes across the Great
Lakes. The center of this surface high crosses the Great Lakes
region Wed before expanding eastward across the Northeast through
Fri, inducing a cold air damming event over our region. Given the
good model agreement and ensemble support, will retain considerable
clouds, above-climatology rain chances, and below normal temps for
this late-week period. -GIH
&&
AVIATION /18Z FRIDAY THROUGH TUESDAY/...
As of 255 PM Friday...
a cold front extending southward across the western NC Piedmont early
this afternoon will advance east through this evening.
VFR conditions with SCT-BKN clouds are generally noted across
central NC with a few locations experiencing MVFR conditions in
prevailing lower CIGs across the Coastal Plain and/or accompanying
widely scattered showers or thunderstorms.
showers and thunderstorms will gradually become more numerous during
the afternoon, especially across the eastern Piedmont, Coastal Plain
and Sandhills with storms moving to the east and northeast. The vast
majority of the showers and storms will shift east out of the RAH CWA
late this afternoon and early evening. An isolated shower or storm
may re-develop around sunset near KFAY or KRWI behind the more
widespread convection with all of the precipitation over by 03z.
clearing skies should push southeast across the region this evening.
There are signals that low level moisture may be stubborn across the
Sandhills and southern Coastal Plain which could result in a period
of redeveloping stratus with IFR CIGs at KFAY and KRWI overnight,
especially after midnight. We have introduced a period of low stratus
after midnight at KFAY and KRWI. winds will become west to northwest
behind the front through the overnight hours at less than 10kts.
Winds will increase on Saturday from the west and become gusty up to
20kts by midday.
Outlook... Another cold front will approach the area on Saturday
afternoon with SCT-BKN cumulus with bases around 5-6kft. The front
will swing across central NC on Saturday evening. There is a small
chance of a brief VFR shower during the mid to late afternoon across
the north with dry weather and clearing skies on saturday night.
Gusty west winds on Saturday afternoon at 10 to 14kts with gusts of
20-25kts will become northwest on Saturday night. Generally fair
weather is expected through Monday with increasing chances of adverse
aviation conditions in scattered showers or thunderstorms on Monday
night into Tuesday. -Blaes
&&
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Blaes
NEAR TERM...Vincent
SHORT TERM...Blaes
LONG TERM...Hartfield
AVIATION...Blaes
[top]
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
632 PM EDT FRI MAY 13 2016
.SYNOPSIS...
A cold front will approach from the west this evening and pass
through the area tonight. A second cold front will pass through
the area Saturday night. High pressure will build in behind the
front Sunday and move offshore Monday. A warm front will lift
north through the area Tuesday night...then a cold front will
approach from the north and linger over or near the area late in
the week.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
As of 630 PM Friday...Lowered pops to slight chc coastal plains
chc interior and likely sern 1/3 of area through the evening
hours. precip will likely be offshore before midnight. Stg
convection mainly confined to sern sxns early this eve. Minor
tweaks to temps to initialize.
The front will push through the area during the evening hours
pushing any ongoing showers or thunderstorms off the coast by
before midnight, followed by clearing skies. Patchy fog will be
possible late with clear skies, light winds, and ground moisture
from the showers and thunderstorms. However, falling dewpoints
should help prevent widespread fog development. Lows tonight
expected in the upper 50s/lower 60s inland to mid 60s along the
coast.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
As of 300 PM Friday...Most of Saturday is expected to be
dry but late in the day a secondary strong cold front with
limited moisture will approach the area, crossing the region
Saturday evening. Best moisture and forcing will coincide over the
northern portion of the area where the highest (30% chance) POPs
will be carried for the afternoon for a scattered shower or
thunderstorm. Highs Saturday will still be quite warm behind the
first weak front. as winds switch around to southwesterly ahead of
the next front, highs will climb into the lower to middle 80s,
except upper 70s on the coast.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
As of 300 PM Friday...No significant changes to previous forecast
with this issuance. Dry and cool period expected Sat night through
Mon...then return of zonal flow aloft with short wave energy
moving in from W-SW will result in unsettled period Tue-Fri. Lack
of model run-to-run consistency results in below normal forecast
confidence for end of week.
Saturday night: Drier and much cooler air will prevail behind the
cold front late Saturday night with lows in the lower to middle
50s expected...except around 60 Outer Banks.
Sunday and Monday: High pressure is forecast to build over the
region Sunday moving offshore Monday while still influencing the
weather. Dry and a much cooler air mass settles over the region
both days with highs Sunday generally in the low 70s with some
60s north and east. Sunday night will be coolest night of the
period as dry and cool high pres ridges in. Based on latest MOS
guidance blend...did adjust min temps down a few degrees to mid
40s inland and mid 50s beaches. Monday will be pleasantly cool
with highs in the low to mid 70s.
Monday night through Wednesday night: Expect unsettled weather
with better precipitation chances this period as a series of short
waves cross the area along with retreating warm front Tuesday and
the slow approach of a cold front mid through late week. Moisture
return and isentropic lift begin as early as late Monday night
with increasing cloud cover and precip chances. Better coverage of
shra/tsra expected Tuesday through Wed night as increase in lift
from short waves crossing in WSW flow aloft...will also have
increasing precip water values over region. Used a blend of of the
various MOS and previous forecast with 30-50 pops through period.
Temperatures will be increasingly warm and humidity values
increasing with highs reaching into the upper 70s to mid 80s and
lows in the 60s.
Thursday and Friday...Have leaned toward WPC and Superblend for
this period with higher chance POPs for thunderstorms Thursday and
Thu night...then low chance for showers Friday. 12Z GFS and ECMWF
have trended faster with front moving through by Thu morning but
then diverge with GFS stalling front just south of area while EC
pushes it farther south. Per above...lack of run-to-run
consistency leads to below normal forecast confidence this period.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
Short Term /Through 18Z Saturday/...
As of 600 pm Friday...Stg. convection has cleared all of the taf
sites early this evening and will dissipate and move offshore
within the next several hours with skies partially clearing. This
in combination with excess low level moisture and light winds will
lead to a period of fog early Saturday morning. At least MVFR
conditions are possible over most of the region with potentially
IFR visibilities possible west of Highway 17. But confidence in
IFR conditions remains somewhat low at this time. VFR conditions
return soon after sunrise as winds will pick up again from the SW
between 5 and 10 knots.
Long Term /Saturday night through Wednesday/...
As of 300 PM Friday...Mainly VFR conditions are expected through
Monday evening outside a chance for scattered showers and
thunderstorms Saturday evening. Conditions improve late Saturday
night as a secondary cold front pushes offshore and High pressure
with drier air settles in with clearing skies which should prevail
into Monday evening. Moisture is expected to increase across the
area late Monday night and Tuesday ahead of a retreating warm
front. Associated showers and Thunderstorms will produce periods
of sub VFR conditions Tue through Wed.
&&
.MARINE...
Short Term /Through Saturday/...
As of 630 PM Friday...S/SW winds are running 10-20 kt with gusts
up to 25 kt acrs the central coastal waters this eve ahead of the
front. The front will move across the waters later this evening
with winds becoming NW and diminishing to below 10 kt after
midnight. NWPS and WW3 in good agreement with seas 3-5 ft this evening
then subsiding to 2-4 ft after midnight.
Winds become SW again during the day on Saturday and increase to
10 to 15 KT during the afternoon ahead of a secondary strong cold
front that approaches late Saturday and crosses the waters
Saturday evening. By late afternoon SW winds will increase 15 to
20 kt Saturday possibly reaching 20 to 25 kt by Saturday evening
over the southern and central waters. Seas will mostly run 3 to 5
feet during the afternoon but could see some 6 foot seas creep
into the outer central waters by late in the day. A brief Small
Craft Advisory may be needed for the central waters but will hold
off on issuing at this time.
Long Term /Saturday night through Wednesday/...
As of 300 PM Friday...The secondary strong cold front crosses the
waters Saturday evening with a period of SCA conditions possible. SW
winds around 20 KT ahead of the front will shift to northwest to
north 15 to 20 kt strongest over the northern and central waters
late Saturday into early Sunday. Seas will generally be 3 to 5 ft
through Sunday but 4 to 6 ft will be possible Saturday night and
early Sunday over the outer waters and a brief Small Craft
Advisory may be needed for the near shore waters.
The flow is forecast to become westerly around 15 kt Sunday as
High pressure builds over the waters then become northerly around
15 kt Sunday night into Monday. Winds are forecast to veer around
to southeast Tuesday and increase to 15 to 20 kt as a warm front
approaches from the south. Seas are forecast to subside to 2 to 4
feet later Sunday and remaining low through Monday night before
possibly increasing to 4 to 6 ft late Tuesday. Low confidence
forecast for Wednesday as latest models are trending toward a
faster cold front passage Wed night...but have leaned to previous
forecast in line with WPC and Superblend of holding it off until
Thu.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...RSB
NEAR TERM...RSB/JAC
SHORT TERM...
LONG TERM...JBM
AVIATION...JAC/JBM/SGK
MARINE...RSB/JAC/JBM
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
632 PM EDT FRI MAY 13 2016
.SYNOPSIS...
A cold front will approach from the west this evening and pass
through the area tonight. A second cold front will pass through
the area Saturday night. High pressure will build in behind the
front Sunday and move offshore Monday. A warm front will lift
north through the area Tuesday night...then a cold front will
approach from the north and linger over or near the area late in
the week.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
As of 630 PM Friday...Lowered pops to slight chc coastal plains
chc interior and likely sern 1/3 of area through the evening
hours. precip will likely be offshore before midnight. Stg
convection mainly confined to sern sxns early this eve. Minor
tweaks to temps to initialize.
The front will push through the area during the evening hours
pushing any ongoing showers or thunderstorms off the coast by
before midnight, followed by clearing skies. Patchy fog will be
possible late with clear skies, light winds, and ground moisture
from the showers and thunderstorms. However, falling dewpoints
should help prevent widespread fog development. Lows tonight
expected in the upper 50s/lower 60s inland to mid 60s along the
coast.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
As of 300 PM Friday...Most of Saturday is expected to be
dry but late in the day a secondary strong cold front with
limited moisture will approach the area, crossing the region
Saturday evening. Best moisture and forcing will coincide over the
northern portion of the area where the highest (30% chance) POPs
will be carried for the afternoon for a scattered shower or
thunderstorm. Highs Saturday will still be quite warm behind the
first weak front. as winds switch around to southwesterly ahead of
the next front, highs will climb into the lower to middle 80s,
except upper 70s on the coast.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
As of 300 PM Friday...No significant changes to previous forecast
with this issuance. Dry and cool period expected Sat night through
Mon...then return of zonal flow aloft with short wave energy
moving in from W-SW will result in unsettled period Tue-Fri. Lack
of model run-to-run consistency results in below normal forecast
confidence for end of week.
Saturday night: Drier and much cooler air will prevail behind the
cold front late Saturday night with lows in the lower to middle
50s expected...except around 60 Outer Banks.
Sunday and Monday: High pressure is forecast to build over the
region Sunday moving offshore Monday while still influencing the
weather. Dry and a much cooler air mass settles over the region
both days with highs Sunday generally in the low 70s with some
60s north and east. Sunday night will be coolest night of the
period as dry and cool high pres ridges in. Based on latest MOS
guidance blend...did adjust min temps down a few degrees to mid
40s inland and mid 50s beaches. Monday will be pleasantly cool
with highs in the low to mid 70s.
Monday night through Wednesday night: Expect unsettled weather
with better precipitation chances this period as a series of short
waves cross the area along with retreating warm front Tuesday and
the slow approach of a cold front mid through late week. Moisture
return and isentropic lift begin as early as late Monday night
with increasing cloud cover and precip chances. Better coverage of
shra/tsra expected Tuesday through Wed night as increase in lift
from short waves crossing in WSW flow aloft...will also have
increasing precip water values over region. Used a blend of of the
various MOS and previous forecast with 30-50 pops through period.
Temperatures will be increasingly warm and humidity values
increasing with highs reaching into the upper 70s to mid 80s and
lows in the 60s.
Thursday and Friday...Have leaned toward WPC and Superblend for
this period with higher chance POPs for thunderstorms Thursday and
Thu night...then low chance for showers Friday. 12Z GFS and ECMWF
have trended faster with front moving through by Thu morning but
then diverge with GFS stalling front just south of area while EC
pushes it farther south. Per above...lack of run-to-run
consistency leads to below normal forecast confidence this period.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
Short Term /Through 18Z Saturday/...
As of 600 pm Friday...Stg. convection has cleared all of the taf
sites early this evening and will dissipate and move offshore
within the next several hours with skies partially clearing. This
in combination with excess low level moisture and light winds will
lead to a period of fog early Saturday morning. At least MVFR
conditions are possible over most of the region with potentially
IFR visibilities possible west of Highway 17. But confidence in
IFR conditions remains somewhat low at this time. VFR conditions
return soon after sunrise as winds will pick up again from the SW
between 5 and 10 knots.
Long Term /Saturday night through Wednesday/...
As of 300 PM Friday...Mainly VFR conditions are expected through
Monday evening outside a chance for scattered showers and
thunderstorms Saturday evening. Conditions improve late Saturday
night as a secondary cold front pushes offshore and High pressure
with drier air settles in with clearing skies which should prevail
into Monday evening. Moisture is expected to increase across the
area late Monday night and Tuesday ahead of a retreating warm
front. Associated showers and Thunderstorms will produce periods
of sub VFR conditions Tue through Wed.
&&
.MARINE...
Short Term /Through Saturday/...
As of 630 PM Friday...S/SW winds are running 10-20 kt with gusts
up to 25 kt acrs the central coastal waters this eve ahead of the
front. The front will move across the waters later this evening
with winds becoming NW and diminishing to below 10 kt after
midnight. NWPS and WW3 in good agreement with seas 3-5 ft this evening
then subsiding to 2-4 ft after midnight.
Winds become SW again during the day on Saturday and increase to
10 to 15 KT during the afternoon ahead of a secondary strong cold
front that approaches late Saturday and crosses the waters
Saturday evening. By late afternoon SW winds will increase 15 to
20 kt Saturday possibly reaching 20 to 25 kt by Saturday evening
over the southern and central waters. Seas will mostly run 3 to 5
feet during the afternoon but could see some 6 foot seas creep
into the outer central waters by late in the day. A brief Small
Craft Advisory may be needed for the central waters but will hold
off on issuing at this time.
Long Term /Saturday night through Wednesday/...
As of 300 PM Friday...The secondary strong cold front crosses the
waters Saturday evening with a period of SCA conditions possible. SW
winds around 20 KT ahead of the front will shift to northwest to
north 15 to 20 kt strongest over the northern and central waters
late Saturday into early Sunday. Seas will generally be 3 to 5 ft
through Sunday but 4 to 6 ft will be possible Saturday night and
early Sunday over the outer waters and a brief Small Craft
Advisory may be needed for the near shore waters.
The flow is forecast to become westerly around 15 kt Sunday as
High pressure builds over the waters then become northerly around
15 kt Sunday night into Monday. Winds are forecast to veer around
to southeast Tuesday and increase to 15 to 20 kt as a warm front
approaches from the south. Seas are forecast to subside to 2 to 4
feet later Sunday and remaining low through Monday night before
possibly increasing to 4 to 6 ft late Tuesday. Low confidence
forecast for Wednesday as latest models are trending toward a
faster cold front passage Wed night...but have leaned to previous
forecast in line with WPC and Superblend of holding it off until
Thu.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...RSB
NEAR TERM...RSB/JAC
SHORT TERM...
LONG TERM...JBM
AVIATION...JAC/JBM/SGK
MARINE...RSB/JAC/JBM
Area Forecast Discussion
National Weather Service Raleigh NC
355 PM EDT FRI MAY 13 2016
.SYNOPSIS...A weak cold front will move off the coast late
tonight. A westerly flow will develop on Saturday before a much
stronger cold front moves across the area Saturday evening.
Chilly high pressure will build in from the west Saturday night
through Monday.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 320 PM Friday...
The surface cold front has made it through much of the triad as of
19z with dew points down to the mid 50s at KINT and KGSO. The front
will continue to slowly push east this afternoon and evening. the
air mass ahead of the front is generally weakly unstable with MLCAPE
values ranging from around 1000 J/Kg in the Sandhills and southern
Coastal Plain to around 500 J/Kg ahead of the front in the Piedmont.
mid level lapse rates are an anemic 5.5 deg C/Km. The low and mid
level flow will continue to strengthen this afternoon as the upper
trough approaches. SPC mesoanalysis shows 0-6km bulk shear values
increasing across central NC with values ranging from 30 to 40 kts
with largely straight hodographs.
Convection has been slow to fire and expand across central NC this
afternoon largely owing to the widespread clouds and more limited
surface destabilization. We still expect another few sets of
convective clusters to develop across the far eastern Piedmont and
more likely the Sandhills as well as the southern and central
Coastal Plain. The convection will move east and northeast with the
best coverage shifting east out of the RAH CWA by 22Z. An isolated
shower or thunderstorm is still possible into the evening hours
across the southeast with low level moisture slow to dislodge as
the cold front slowly advances east. all of the precipitation should
end by mid evening.
The cold front will advance slowly east this evening and slow across
the Sandhills and southern Coastal plain overnight. While skies
clear behind the front across much of central NC, an area of shallow
stratus may develop in the southeast. Lows tonight will range in the
lower 50s northwest in the Triad to the upper 50s to around 60
elsewhere. -blaes
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
As of 355 PM Friday...
a strong northern stream shortwave trough will dive across the Ohio
Valley Saturday morning and off the Mid Atlantic coast on Saturday
evening. The associated cold front will move across central NC late
Saturday afternoon or early evening. A pronounced low-level westerly
flow will develop ahead of the front resulting in good mixing and a
relatively dry boundary layer. while the best forcing for ascent and
greater moisture associated with the shortwave will be located to
our north in the VA and points north, a shallow layer of moisture
and instability atop the mixed layer could generate a few showers
and possibly a thunderstorm. Given the very dry pre-frontal
environment, convective coverage should be quite limited. Behind the
front, even drier and cooler air will surge into the region.
Saturday should feature warm conditions with lots of morning
sunshine followed by some increasing clouds. Highs will range
between 80 and 85 degrees with a west to southwest wind at 10 to 15
mph with gusts of 20 to 25mph during the afternoon. Mainly clear
skies with chilly lows in the upper 40s to lower 50s are expected on
Saturday night. -blaes
&&
.LONG TERM /Sunday through Friday/...
As of 245 PM Friday...
Sun-Mon: Cool and dry. The polar cold front will have pushed to our
south by Sun morning, with thicknesses plunging to 40-50 m below
normal as cool high pressure builds into and over the area from the
west. Expect mostly clear skies Sun/Sun night. Highs around 10 deg F
below normal, in the upper 60s to lower 70s. Lows 44-50. Forecast
soundings do suggest the potential for orographically enhanced
cirrus cloudiness Sun night into early Mon morning, given the fast
mid-high level WNW flow increasing with height, improving moisture
aloft, and shearing mid level vorticity passing just to our north.
Regardless of this occurring or not, we should still see increasing
clouds through the day Mon as the mid level flow flattens and
becomes WSW with a weak wave crossing the lower Miss Valley late in
the day. Thicknesses rebound slightly after the chilly start,
supporting highs Mon from around 70 to the mid 70s.
Mon night through Tue night: The aforementioned shortwave trough
will cross the Deep South and Southeast Mon night and Tue. As the
surface high shifts off the NC/VA coast, the frontal zone just to
our south will edge back northward as a warm front, and the
increasing overrunning flow drawing both Atlantic and Gulf moisture
up and over the frontal zone should lead to widespread rain
development over NC. Confidence in the details is low due to
differences in timing and placement of best rain chances on both the
deterministic models and on ensemble members (the GEFS
specifically). But overall, rain chances will be increasing Mon
night through Tue, to good chance or likely, with perhaps a relative
lull Tue night as the departure of the weak wave as well as a
corresponding strengthening surface low coincides with diurnal
cooling and stabilizing. The GFS and ECMWF both appear to be
converging on a solution in which the front moves into northern NC
but stalls or dips back southward further into the state late Tue
into Tue night, nudged southward by the circulation around the
offshore-moving surface low, with a cool stable pool over northern
NC. after lows Mon night in the mid 50s to around 60, highs Tue
should reflect a smaller diurnal change, with highs from around 70
NW to the mid-upper 70s S. Lows Tue night 58-65 with clouds and
drizzle.
Wed through Fri: Trends favor continued unsettled weather with below
normal temps, as an active fast mid level WSW flow persists. The
frontal zone initially stretching across northern NC is expected to
be pushed southward into southern NC by dense high pressure, which
itself is reinforced by confluent flow aloft around a positively
tilted mid level low from the Canadian Maritimes across the Great
Lakes. The center of this surface high crosses the Great Lakes
region Wed before expanding eastward across the Northeast through
Fri, inducing a cold air damming event over our region. Given the
good model agreement and ensemble support, will retain considerable
clouds, above-climatology rain chances, and below normal temps for
this late-week period. -gih
&&
AVIATION /18Z FRIDAY THROUGH TUESDAY/...
As of 255 PM Friday...
a cold front extending southward across the western NC Piedmont early
this afternoon will advance east through this evening.
VFR conditions with SCT-BKN clouds are generally noted across
central NC with a few locations experiencing MVFR conditions in
prevailing lower CIGs across the Coastal Plain and/or accompanying
widely scattered showers or thunderstorms.
showers and thunderstorms will gradually become more numerous during
the afternoon, especially across the eastern Piedmont, Coastal Plain
and Sandhills with storms moving to the east and northeast. The vast
majority of the showers and storms will shift east out of the RAH CWA
late this afternoon and early evening. An isolated shower or storm
may re-develop around sunset near KFAY or KRWI behind the more
widespread convection with all of the precipitation over by 03z.
clearing skies should push southeast across the region this evening.
There are signals that low level moisture may be stubborn across the
Sandhills and southern Coastal Plain which could result in a period
of redeveloping stratus with IFR CIGs at KFAY and KRWI overnight,
especially after midnight. We have introduced a period of low stratus
after midnight at KFAY and KRWI. winds will become west to northwest
behind the front through the overnight hours at less than 10kts.
Winds will increase on Saturday from the west and become gusty up to
20kts by midday.
Outlook... Another cold front will approach the area on Saturday
afternoon with SCT-BKN cumulus with bases around 5-6kft. The front
will swing across central NC on Saturday evening. There is a small
chance of a brief VFR shower during the mid to late afternoon across
the north with dry weather and clearing skies on saturday night.
Gusty west winds on Saturday afternoon at 10 to 14kts with gusts of
20-25kts will become northwest on Saturday night. Generally fair
weather is expected through Monday with increasing chances of adverse
aviation conditions in scattered showers or thunderstorms on Monday
night into Tuesday. -blaes
&&
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...blaes
NEAR TERM...Blaes
SHORT TERM...Blaes
LONG TERM...Hartfield
AVIATION...blaes
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
353 PM EDT FRI MAY 13 2016
.SYNOPSIS...
A cold front will approach from the west this evening and pass
through the area tonight. A second cold front will pass through
the area Saturday night. High pressure will build in behind the
front Sunday and move offshore Monday. A warm front will lift
north through the area Tuesday night...then a cold front will
approach from the north and linger over or near the area late in
the week.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
As of 300 PM Friday...through mid afternoon cloud cover helped to
limit instability. However seeing a few breaks to the west and
shower/tstm activity is strengthening somewhat. Still expect a
chance for some storms to become severe in areas that see some
clearing and increased instability with wind gusts being the main
threat.
The front will push through the area during the evening hours
pushing any ongoing showers or thunderstorms off the coast by
around midnight, followed by clearing skies. Patchy fog will be
possible late with clear skies, light winds, and ground moisture
from the showers and thunderstorms. However, falling dewpoints
should help prevent widespread fog development. Lows tonight
expected in the upper 50s/lower 60s inland to mid 60s along the
coast.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
As of 300 PM Friday...Most of Saturday is expected to be
dry but late in the day a secondary strong cold front with
limited moisture will approach the area, crossing the region
Saturday evening. Best moisture and forcing will coincide over the
northern portion of the area where the highest (30% chance) POPs
will be carried for the afternoon for a scattered shower or
thunderstorm. Highs Saturday will still be quite warm behind the
first weak front. as winds switch around to southwesterly ahead of
the next front, highs will climb into the lower to middle 80s,
except upper 70s on the coast.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
As of 300 PM Friday...No significant changes to previous forecast
with this issuance. Dry and cool period expected Sat night through
Mon...then return of zonal flow aloft with short wave energy
moving in from W-SW will result in unsettled period Tue-Fri. Lack
of model run-to-run consistency results in below normal forecast
confidence for end of week.
Saturday night: Drier and much cooler air will prevail behind the
cold front late Saturday night with lows in the lower to middle
50s expected...except around 60 Outer Banks.
Sunday and Monday: High pressure is forecast to build over the
region Sunday moving offshore Monday while still influencing the
weather. Dry and a much cooler air mass settles over the region
both days with highs Sunday generally in the low 70s with some
60s north and east. Sunday night will be coolest night of the
period as dry and cool high pres ridges in. Based on latest MOS
guidance blend...did adjust min temps down a few degrees to mid
40s inland and mid 50s beaches. Monday will be pleasantly cool
with highs in the low to mid 70s.
Monday night through Wednesday night: Expect unsettled weather
with better precipitation chances this period as a series of short
waves cross the area along with retreating warm front Tuesday and
the slow approach of a cold front mid through late week. Moisture
return and isentropic lift begin as early as late Monday night
with increasing cloud cover and precip chances. Better coverage of
shra/tsra expected Tuesday through Wed night as increase in lift
from short waves crossing in WSW flow aloft...will also have
increasing precip water values over region. Used a blend of of the
various MOS and previous forecast with 30-50 pops through period.
Temperatures will be increasingly warm and humidity values
increasing with highs reaching into the upper 70s to mid 80s and
lows in the 60s.
Thursday and Friday...Have leaned toward WPC and Superblend for
this period with higher chance POPs for thunderstorms Thursday and
Thu night...then low chance for showers Friday. 12Z GFS and ECMWF
have trended faster with front moving through by Thu morning but
then diverge with GFS stalling front just south of area while EC
pushes it farther south. Per above...lack of run-to-run
consistency leads to below normal forecast confidence this period.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
Short Term /Through 18Z Saturday/...
As of 200 pm friday...Conditions have been fluctuating between
VFR and MVFR this afternoon as scattered showers and thunderstorms
continue to cross the airspace. Ceilings are averaging between 3k
and 4k feet under SW winds around 10 knots. Thunderstorms are
expected to remain scattered through the region this afternoon as
a cold front crosses the state. Activity will dissipate by evening
and skies will partially clear. This in combination with excess
low level moisture and light winds will lead to a period of fog
early Saturday morning. At least MVFR conditions are possible over
most of the region with potentially IFR visibilities possible west
of Highway 17. But confidence in IFR conditions remains somewhat
low at this time. VFR conditions return soon after sunrise as
winds will pick up again from the SW between 5 and 10 knots.
Long Term /Saturday night through Wednesday/...
As of 300 PM Friday...Mainly VFR conditions are expected through
Monday evening outside a chance for scattered showers and
thunderstorms Saturday evening. Conditions improve late Saturday
night as a secondary cold front pushes offshore and High pressure
with drier air settles in with clearing skies which should prevail
into Monday evening. Moisture is expected to increase across the
area late Monday night and Tuesday ahead of a retreating warm
front. Associated showers and Thunderstorms will produce periods
of sub VFR conditions Tue throgh Wed.
&&
.MARINE...
Short Term /Through Saturday/...
As of 300 PM Friday...S/SW winds are running 10-20 kt as the
pressure gradient tightens ahead of the front. winds in the
central outer waters are flirting with sca conditions but expect
them to be mostly below 25 kt sustained with perhaps a brief
period gusting to 25 kt. The front will move across the waters
this evening with winds becoming NW and diminishing to below 10 kt
after midnight. NWPS and WW3 in good agreement with seas 3-5 ft
this afternoon and evening then subsided to 2-4 ft after midnight
tonight.
Winds become SW again during the day on Saturday and increase to
10 to 15 KT during the afternoon ahead of a secondary strong cold
front that approaches late Saturday and crosses the waters
Saturday evening. By late afternoon SW winds will increase 15 to
20 kt Saturday possibly reaching 20 to 25 kt by Saturday evening
over the southern and central waters. Seas will mostly run 3 to 5
feet during the afternoon but could see some 6 foot seas creep
into the outer central waters by late in the day. A brief Small
Craft Advisory may be needed for the central waters but will hold
off on issuing at this time.
Long Term /Saturday night through Wednesday/...
As of 300 PM Friday...The secondary strong cold front crosses the
waters Saturday evening with a period of SCA conditions possible. SW
winds arund 20 KT ahead of the front will shift to northwest to
north 15 to 20 kt strongest over the northern and central waters
late Saturday into early Sunday. Seas will generally be 3 to 5 ft
through Sunday but 4 to 6 ft will be possible Saturday night and
early Sunday over the outer waters and a brief Small Craft
Advisory may be needed for the near shore waters.
The flow is forecast to become westerly around 15 kt Sunday as
High pressure builds over the waters then become northerly around
15 kt Sunday night into Monday. Winds are forecast to veer around
to southeast Tuesday and increase to 15 to 20 kt as a warm front
approaches from the south. Seas are forecast to subside to 2 to 4
feet later Sunday and remaining low through Monday night before
possibly increasing to 4 to 6 ft late Tuesday. Low confidence
forecast for Wednesday as latest models are trending toward a
faster cold front passage Wed night...but have leaned to previous
forecast in line with WPC and Superblend of holding it off until
Thu.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...RSB
NEAR TERM...RSB
SHORT TERM...
LONG TERM...JBM
AVIATION...JBM/SGK
MARINE...RSB/JBM
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
353 PM EDT FRI MAY 13 2016
.SYNOPSIS...
A cold front will approach from the west this evening and pass
through the area tonight. A second cold front will pass through
the area Saturday night. High pressure will build in behind the
front Sunday and move offshore Monday. A warm front will lift
north through the area Tuesday night...then a cold front will
approach from the north and linger over or near the area late in
the week.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
As of 300 PM Friday...through mid afternoon cloud cover helped to
limit instability. However seeing a few breaks to the west and
shower/tstm activity is strengthening somewhat. Still expect a
chance for some storms to become severe in areas that see some
clearing and increased instability with wind gusts being the main
threat.
The front will push through the area during the evening hours
pushing any ongoing showers or thunderstorms off the coast by
around midnight, followed by clearing skies. Patchy fog will be
possible late with clear skies, light winds, and ground moisture
from the showers and thunderstorms. However, falling dewpoints
should help prevent widespread fog development. Lows tonight
expected in the upper 50s/lower 60s inland to mid 60s along the
coast.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
As of 300 PM Friday...Most of Saturday is expected to be
dry but late in the day a secondary strong cold front with
limited moisture will approach the area, crossing the region
Saturday evening. Best moisture and forcing will coincide over the
northern portion of the area where the highest (30% chance) POPs
will be carried for the afternoon for a scattered shower or
thunderstorm. Highs Saturday will still be quite warm behind the
first weak front. as winds switch around to southwesterly ahead of
the next front, highs will climb into the lower to middle 80s,
except upper 70s on the coast.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
As of 300 PM Friday...No significant changes to previous forecast
with this issuance. Dry and cool period expected Sat night through
Mon...then return of zonal flow aloft with short wave energy
moving in from W-SW will result in unsettled period Tue-Fri. Lack
of model run-to-run consistency results in below normal forecast
confidence for end of week.
Saturday night: Drier and much cooler air will prevail behind the
cold front late Saturday night with lows in the lower to middle
50s expected...except around 60 Outer Banks.
Sunday and Monday: High pressure is forecast to build over the
region Sunday moving offshore Monday while still influencing the
weather. Dry and a much cooler air mass settles over the region
both days with highs Sunday generally in the low 70s with some
60s north and east. Sunday night will be coolest night of the
period as dry and cool high pres ridges in. Based on latest MOS
guidance blend...did adjust min temps down a few degrees to mid
40s inland and mid 50s beaches. Monday will be pleasantly cool
with highs in the low to mid 70s.
Monday night through Wednesday night: Expect unsettled weather
with better precipitation chances this period as a series of short
waves cross the area along with retreating warm front Tuesday and
the slow approach of a cold front mid through late week. Moisture
return and isentropic lift begin as early as late Monday night
with increasing cloud cover and precip chances. Better coverage of
shra/tsra expected Tuesday through Wed night as increase in lift
from short waves crossing in WSW flow aloft...will also have
increasing precip water values over region. Used a blend of of the
various MOS and previous forecast with 30-50 pops through period.
Temperatures will be increasingly warm and humidity values
increasing with highs reaching into the upper 70s to mid 80s and
lows in the 60s.
Thursday and Friday...Have leaned toward WPC and Superblend for
this period with higher chance POPs for thunderstorms Thursday and
Thu night...then low chance for showers Friday. 12Z GFS and ECMWF
have trended faster with front moving through by Thu morning but
then diverge with GFS stalling front just south of area while EC
pushes it farther south. Per above...lack of run-to-run
consistency leads to below normal forecast confidence this period.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
Short Term /Through 18Z Saturday/...
As of 200 pm friday...Conditions have been fluctuating between
VFR and MVFR this afternoon as scattered showers and thunderstorms
continue to cross the airspace. Ceilings are averaging between 3k
and 4k feet under SW winds around 10 knots. Thunderstorms are
expected to remain scattered through the region this afternoon as
a cold front crosses the state. Activity will dissipate by evening
and skies will partially clear. This in combination with excess
low level moisture and light winds will lead to a period of fog
early Saturday morning. At least MVFR conditions are possible over
most of the region with potentially IFR visibilities possible west
of Highway 17. But confidence in IFR conditions remains somewhat
low at this time. VFR conditions return soon after sunrise as
winds will pick up again from the SW between 5 and 10 knots.
Long Term /Saturday night through Wednesday/...
As of 300 PM Friday...Mainly VFR conditions are expected through
Monday evening outside a chance for scattered showers and
thunderstorms Saturday evening. Conditions improve late Saturday
night as a secondary cold front pushes offshore and High pressure
with drier air settles in with clearing skies which should prevail
into Monday evening. Moisture is expected to increase across the
area late Monday night and Tuesday ahead of a retreating warm
front. Associated showers and Thunderstorms will produce periods
of sub VFR conditions Tue throgh Wed.
&&
.MARINE...
Short Term /Through Saturday/...
As of 300 PM Friday...S/SW winds are running 10-20 kt as the
pressure gradient tightens ahead of the front. winds in the
central outer waters are flirting with sca conditions but expect
them to be mostly below 25 kt sustained with perhaps a brief
period gusting to 25 kt. The front will move across the waters
this evening with winds becoming NW and diminishing to below 10 kt
after midnight. NWPS and WW3 in good agreement with seas 3-5 ft
this afternoon and evening then subsided to 2-4 ft after midnight
tonight.
Winds become SW again during the day on Saturday and increase to
10 to 15 KT during the afternoon ahead of a secondary strong cold
front that approaches late Saturday and crosses the waters
Saturday evening. By late afternoon SW winds will increase 15 to
20 kt Saturday possibly reaching 20 to 25 kt by Saturday evening
over the southern and central waters. Seas will mostly run 3 to 5
feet during the afternoon but could see some 6 foot seas creep
into the outer central waters by late in the day. A brief Small
Craft Advisory may be needed for the central waters but will hold
off on issuing at this time.
Long Term /Saturday night through Wednesday/...
As of 300 PM Friday...The secondary strong cold front crosses the
waters Saturday evening with a period of SCA conditions possible. SW
winds arund 20 KT ahead of the front will shift to northwest to
north 15 to 20 kt strongest over the northern and central waters
late Saturday into early Sunday. Seas will generally be 3 to 5 ft
through Sunday but 4 to 6 ft will be possible Saturday night and
early Sunday over the outer waters and a brief Small Craft
Advisory may be needed for the near shore waters.
The flow is forecast to become westerly around 15 kt Sunday as
High pressure builds over the waters then become northerly around
15 kt Sunday night into Monday. Winds are forecast to veer around
to southeast Tuesday and increase to 15 to 20 kt as a warm front
approaches from the south. Seas are forecast to subside to 2 to 4
feet later Sunday and remaining low through Monday night before
possibly increasing to 4 to 6 ft late Tuesday. Low confidence
forecast for Wednesday as latest models are trending toward a
faster cold front passage Wed night...but have leaned to previous
forecast in line with WPC and Superblend of holding it off until
Thu.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...RSB
NEAR TERM...RSB
SHORT TERM...
LONG TERM...JBM
AVIATION...JBM/SGK
MARINE...RSB/JBM
Area Forecast Discussion
National Weather Service Raleigh NC
320 PM EDT FRI MAY 13 2016
.SYNOPSIS...A weak cold front will move off the coast this evening,
followed by high pressure that will build briefly overhead tonight.
A much stronger cold front will cross the region Saturday evening.
High pressure will build in from the west Saturday night through
Monday.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 320 PM Friday...
The surface cold front has made it through much of the triad as of
19z with dew points down to the mid 50s at KINT and KGSO. The front
will continue to slowly push east this afternoon and evening. the
air mass ahead of the front is generally weakly unstable with MLCAPE
values ranging from around 1000 J/Kg in the Sandhills and southern
Coastal Plain to around 500 J/Kg ahead of the front in the Piedmont.
mid level lapse rates are an anemic 5.5 deg C/Km. The low and mid
level flow will continue to strengthen this afternoon as the upper
trough approaches. SPC mesoanalysis shows 0-6km bulk shear values
increasing across central NC with values ranging from 30 to 40 kts
with largely straight hodographs.
Convection has been slow to fire and expand across central NC this
afternoon largely owing to the widespread clouds and more limited
surface destabilization. We still expect another few sets of
convective clusters to develop across the far eastern Piedmont and
more likely the Sandhills as well as the southern and central
Coastal Plain. The convection will move east and northeast with the
best coverage shifting east out of the RAH CWA by 22Z. An isolated
shower or thunderstorm is still possible into the evening hours
across the southeast with low level moisture slow to dislodge as
the cold front slowly advances east. all of the precipitation should
end by mid evening.
The cold front will advance slowly east this evening and slow across
the Sandhills and southern Coastal plain overnight. While skies
clear behind the front across much of central NC, an area of shallow
stratus may develop in the southeast. Lows tonight will range in the
lower 50s northwest in the Triad to the upper 50s to around 60
elsewhere. -blaes
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
As of 235 AM Friday...
The secondary cold front is still on target to push through our
region saturday afternoon. a very dry boundary layer will exist with
surface dew points likely only 50-55 or so in the pre-frontal
environment. Once the front passes, even drier and eventually cooler
air will surge into the region. We will maintain the 20 POP for an
isolated shower or thunderstorm in the northeast zones during the
afternoon. Otherwise, dry and warm SW-W winds 10-20 MPH will become
NW after the front passes. Highs generally 80 to 85 expected. Much
cooler air will arrive Saturday night with clear skies. Lows in the
45-53 range expected NW to SE. The winds will be gusty to 25 mph
during the evening, before diminishing to around 10 mph after
midnight.
&&
.LONG TERM /Sunday through Friday/...
As of 245 PM Friday...
Sun-Mon: Cool and dry. The polar cold front will have pushed to our
south by Sun morning, with thicknesses plunging to 40-50 m below
normal as cool high pressure builds into and over the area from the
west. Expect mostly clear skies Sun/Sun night. Highs around 10 deg F
below normal, in the upper 60s to lower 70s. Lows 44-50. Forecast
soundings do suggest the potential for orographically enhanced
cirrus cloudiness Sun night into early Mon morning, given the fast
mid-high level WNW flow increasing with height, improving moisture
aloft, and shearing mid level vorticity passing just to our north.
Regardless of this occurring or not, we should still see increasing
clouds through the day Mon as the mid level flow flattens and
becomes WSW with a weak wave crossing the lower Miss Valley late in
the day. Thicknesses rebound slightly after the chilly start,
supporting highs Mon from around 70 to the mid 70s.
Mon night through Tue night: The aforementioned shortwave trough
will cross the Deep South and Southeast Mon night and Tue. As the
surface high shifts off the NC/VA coast, the frontal zone just to
our south will edge back northward as a warm front, and the
increasing overrunning flow drawing both Atlantic and Gulf moisture
up and over the frontal zone should lead to widespread rain
development over NC. Confidence in the details is low due to
differences in timing and placement of best rain chances on both the
deterministic models and on ensemble members (the GEFS
specifically). But overall, rain chances will be increasing Mon
night through Tue, to good chance or likely, with perhaps a relative
lull Tue night as the departure of the weak wave as well as a
corresponding strengthening surface low coincides with diurnal
cooling and stabilizing. The GFS and ECMWF both appear to be
converging on a solution in which the front moves into northern NC
but stalls or dips back southward further into the state late Tue
into Tue night, nudged southward by the circulation around the
offshore-moving surface low, with a cool stable pool over northern
NC. after lows Mon night in the mid 50s to around 60, highs Tue
should reflect a smaller diurnal change, with highs from around 70
NW to the mid-upper 70s S. Lows Tue night 58-65 with clouds and
drizzle.
Wed through Fri: Trends favor continued unsettled weather with below
normal temps, as an active fast mid level WSW flow persists. The
frontal zone initially stretching across northern NC is expected to
be pushed southward into southern NC by dense high pressure, which
itself is reinforced by confluent flow aloft around a positively
tilted mid level low from the Canadian Maritimes across the Great
Lakes. The center of this surface high crosses the Great Lakes
region Wed before expanding eastward across the Northeast through
Fri, inducing a cold air damming event over our region. Given the
good model agreement and ensemble support, will retain considerable
clouds, above-climatology rain chances, and below normal temps for
this late-week period. -gih
&&
AVIATION /18Z FRIDAY THROUGH TUESDAY/...
As of 255 PM Friday...
a cold front extending southward across the western NC Piedmont early
this afternoon will advance east through this evening.
VFR conditions with SCT-BKN clouds are generally noted across
central NC with a few locations experiencing MVFR conditions in
prevailing lower CIGs across the Coastal Plain and/or accompanying
widely scattered showers or thunderstorms.
showers and thunderstorms will gradually become more numerous during
the afternoon, especially across the eastern Piedmont, Coastal Plain
and Sandhills with storms moving to the east and northeast. The vast
majority of the showers and storms will shift east out of the RAH CWA
late this afternoon and early evening. An isolated shower or storm
may re-develop around sunset near KFAY or KRWI behind the more
widespread convection with all of the precipitation over by 03z.
clearing skies should push southeast across the region this evening.
There are signals that low level moisture may be stubborn across the
Sandhills and southern Coastal Plain which could result in a period
of redeveloping stratus with IFR CIGs at KFAY and KRWI overnight,
especially after midnight. We have introduced a period of low stratus
after midnight at KFAY and KRWI. winds will become west to northwest
behind the front through the overnight hours at less than 10kts.
Winds will increase on Saturday from the west and become gusty up to
20kts by midday.
Outlook... Another cold front will approach the area on Saturday
afternoon with SCT-BKN cumulus with bases around 5-6kft. The front
will swing across central NC on Saturday evening. There is a small
chance of a brief VFR shower during the mid to late afternoon across
the north with dry weather and clearing skies on saturday night.
Gusty west winds on Saturday afternoon at 10 to 14kts with gusts of
20-25kts will become northwest on Saturday night. Generally fair
weather is expected through Monday with increasing chances of adverse
aviation conditions in scattered showers or thunderstorms on Monday
night into Tuesday. -blaes
&&
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...26/Hartfield
NEAR TERM...Blaes
SHORT TERM...Badgett
LONG TERM...Hartfield
AVIATION...blaes
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
301 PM EDT FRI MAY 13 2016
.SYNOPSIS...
A cold front will approach from the west today and pass through
the area tonight. A second cold front will pass through the area
Saturday night. High pressure will build in behind the front
Sunday and move offshore Monday. A warm front will lift north
through the area Tuesday night...then a cold front will approach
from the north and linger over or near the area late in the week.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 300 PM Friday...through mid afternoon cloud cover helped to
limit instability. However seeing a few breaks to the west and
shower/tstm activity is strengthening somewhat. Still expect a
chance for some storms to become severe in areas that see some
clearing and increased instability with wind gusts being the main
threat.
The front will push through the area during the evening hours
pushing any ongoing showers or thunderstorms off the coast by
around midnight, followed by clearing skies. Patchy fog will be
possible late with clear skies, light winds, and ground moisture
from the showers and thunderstorms. However, falling dewpoints
should help prevent widespread fog development. Lows tonight
expected in the upper 50s/lower 60s inland to mid 60s along the
coast.
&&
.SHORT TERM /SATURDAY/...
As of 300 PM Friday...Most of Saturday is expected to be
dry but late in the day a secondary strong cold front with
limited moisture will approach the area, crossing the region
Saturday evening. Best moisture and forcing will coincide over the
northern portion of the area where the highest (30% chance) POPs
will be carried for the afternoon for a scattered shower or
thunderstorm. Highs Saturday will still be quite warm behind the
first weak front. as winds switch around to southwesterly ahead of
the next front, highs will climb into the lower to middle 80s,
except upper 70s on the coast.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
As of 330 am Friday...The long term period will feature mostly
dry weather over the weekend then much cooler temps are expected
Sunday and Monday. A return to a warmer and more active weather
pattern is expected by Tues which should continue through the end
of next week.
Saturday night: Drier and much cooler air will prevail behind the
cold front late Saturday night with lows in the lower to middle
50s expected.
Sunday and Monday: High pressure is forecast to build over the
region Sunday moving offshore Monday while still influencing the
weather. Dry and a much cooler air mass settles over the region
both days with highs Sunday generally in the low 70s with some
60s north and east. Sunday night will be coolest night of the
period as dry and cool high pres ridges in with lows in the upper
40s inland to mid 50s beaches. Monday will be pleasantly cool with
highs in the low to mid 70s.
Tuesday through Thursday: Expect unsettled weather with better
precipitation chances this period as a series of short waves cross
the area along with retreating warm front Tuesday and the slow
approach of a cold front mid through late week. Moisture return
and isentropic lift begin as early as late Monday night with
increasing cloud cover and precip chances. Better coverage of
shra/tsra expected Tuesday through Thursday as increase in lift
from short waves crossing in WSW flow aloft...will also have
increasing precip water values over region. Used a blend of of the
various MOS and previous forecast with 30-50 pops through
Thursday. Temperatures will be increasingly warm and humidity
values increasing with highs reaching into the upper 70s to mid
80s and lows in the 60s.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
Short Term /Through Saturday Afternoon/...
As of 200 pm friday...Conditions have been fluctuating between VFR
and MVFR this afternoon as scattered showers and thunderstorms
continue to cross the airspace. Ceilings are averaging between 3k
and 4k feet under SW winds around 10 knots. Thunderstorms are
expected to remain scattered through the region this afternoon as
a cold front crosses the state. Activity will dissipate by
evening and skies will partially clear. This in combination with
excess low level moisture and light winds will lead to a period of
fog early Saturday morning. At least MVFR conditions are possible
over most of the region with potentially IFR visibilities possible
west of Highway 17. But confidence in IFR conditions remains
somewhat low at this time. VFR conditions return soon after
sunrise as winds will pick up again from the SW between 5 and 10
knots.
Long Term /Saturday through Tuesday/...
As of 330 am Friday...Mainly VFR conditions are expected through
Monday evening outside a chance for scattered showers and
thunderstorms late Saturday into Saturday evening. Conditions
improve late Saturday night as a secondary cold front pushes
offshore and High pressure with drier air settles in with clearing
skies which should prevail into Monday evening. Moisture is
expected to increase across the area late Monday night and Tuesday
ahead of a retreating warm front. Associated showers and
Thunderstorms will produce periods of sub VFR conditions
especially Tuesday and beyond as the pattern becomes more active.
&&
.MARINE...
Short Term /through tonight/...
As of 300 PM Friday...S/SW winds are running 10-20 kt as the
pressure gradient tightens ahead of the front. winds in the
central outer waters are flirting with sca conditions but expect
them to be mostly below 25 kt sustained with perhaps a brief
period gusting to 25 kt. The front will move across the waters
this evening with winds becoming NW and diminishing to below 10
kt after midnight. NWPS and WW3 in good agreement with seas
3-5 ft this afternoon and evening then subsided to 2-4 ft after
midnight tonight.
winds become SW again during the day on saturday and increase to
10 to 15 KT during the afternoon ahead of a secondary strong cold
front that approaches late Saturday and crosses the waters
Saturday evening. By late afternoon SW winds will increase 15 to
20 kt Saturday possibly reaching 20 to 25 kt by Saturday evening
over the southern and central waters. seas will mostly run 3 to 5
feet during the afternoon but could see some 6 foot seas creep
into the outer central waters by late in the day. a brief Small
Craft Advisory may be needed for the central waters but will hold
off on issuing at this time.
Long Term /Saturday through Tuesday/...
As of 330 am Friday...The secondary strong cold front crosses the
waters Saturday evening. Ahead of the front SW winds will increase
15 to 20 kt Saturday possibly reaching 20 to 25 kt Saturday
evening over the southern and central waters. Behind the front the
winds will become northwest to north 15 to 20 kt strongest over
the northern and central waters late Saturday into early Sunday.
Seas will generally 3 to 5 ft through Sunday but 4 to 6 ft will be
possible Saturday night and early Sunday over the outer waters and
a brief Small Craft Advisory may be needed for the near shore
waters.
The flow is forecast to become westerly around 15 kt Sunday as
High pressure builds over the waters then become northerly around
15 kt Sunday night into Monday. Winds are forecast to veer around
to southeast Tuesday and increase to 15 to 20 kt as a warm front
approaches from the south. Seas are forecast to subside to 2 to 4
feet later Sunday and remaining low through Monday night before
possibly increasing to 4 to 6 ft late Tuesday.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...RSB
NEAR TERM...RSB
SHORT TERM...RSB
LONG TERM...JBM
AVIATION...JBM/SGK
MARINE...RSB/JBM
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
301 PM EDT FRI MAY 13 2016
.SYNOPSIS...
A cold front will approach from the west today and pass through
the area tonight. A second cold front will pass through the area
Saturday night. High pressure will build in behind the front
Sunday and move offshore Monday. A warm front will lift north
through the area Tuesday night...then a cold front will approach
from the north and linger over or near the area late in the week.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 300 PM Friday...through mid afternoon cloud cover helped to
limit instability. However seeing a few breaks to the west and
shower/tstm activity is strengthening somewhat. Still expect a
chance for some storms to become severe in areas that see some
clearing and increased instability with wind gusts being the main
threat.
The front will push through the area during the evening hours
pushing any ongoing showers or thunderstorms off the coast by
around midnight, followed by clearing skies. Patchy fog will be
possible late with clear skies, light winds, and ground moisture
from the showers and thunderstorms. However, falling dewpoints
should help prevent widespread fog development. Lows tonight
expected in the upper 50s/lower 60s inland to mid 60s along the
coast.
&&
.SHORT TERM /SATURDAY/...
As of 300 PM Friday...Most of Saturday is expected to be
dry but late in the day a secondary strong cold front with
limited moisture will approach the area, crossing the region
Saturday evening. Best moisture and forcing will coincide over the
northern portion of the area where the highest (30% chance) POPs
will be carried for the afternoon for a scattered shower or
thunderstorm. Highs Saturday will still be quite warm behind the
first weak front. as winds switch around to southwesterly ahead of
the next front, highs will climb into the lower to middle 80s,
except upper 70s on the coast.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
As of 330 am Friday...The long term period will feature mostly
dry weather over the weekend then much cooler temps are expected
Sunday and Monday. A return to a warmer and more active weather
pattern is expected by Tues which should continue through the end
of next week.
Saturday night: Drier and much cooler air will prevail behind the
cold front late Saturday night with lows in the lower to middle
50s expected.
Sunday and Monday: High pressure is forecast to build over the
region Sunday moving offshore Monday while still influencing the
weather. Dry and a much cooler air mass settles over the region
both days with highs Sunday generally in the low 70s with some
60s north and east. Sunday night will be coolest night of the
period as dry and cool high pres ridges in with lows in the upper
40s inland to mid 50s beaches. Monday will be pleasantly cool with
highs in the low to mid 70s.
Tuesday through Thursday: Expect unsettled weather with better
precipitation chances this period as a series of short waves cross
the area along with retreating warm front Tuesday and the slow
approach of a cold front mid through late week. Moisture return
and isentropic lift begin as early as late Monday night with
increasing cloud cover and precip chances. Better coverage of
shra/tsra expected Tuesday through Thursday as increase in lift
from short waves crossing in WSW flow aloft...will also have
increasing precip water values over region. Used a blend of of the
various MOS and previous forecast with 30-50 pops through
Thursday. Temperatures will be increasingly warm and humidity
values increasing with highs reaching into the upper 70s to mid
80s and lows in the 60s.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
Short Term /Through Saturday Afternoon/...
As of 200 pm friday...Conditions have been fluctuating between VFR
and MVFR this afternoon as scattered showers and thunderstorms
continue to cross the airspace. Ceilings are averaging between 3k
and 4k feet under SW winds around 10 knots. Thunderstorms are
expected to remain scattered through the region this afternoon as
a cold front crosses the state. Activity will dissipate by
evening and skies will partially clear. This in combination with
excess low level moisture and light winds will lead to a period of
fog early Saturday morning. At least MVFR conditions are possible
over most of the region with potentially IFR visibilities possible
west of Highway 17. But confidence in IFR conditions remains
somewhat low at this time. VFR conditions return soon after
sunrise as winds will pick up again from the SW between 5 and 10
knots.
Long Term /Saturday through Tuesday/...
As of 330 am Friday...Mainly VFR conditions are expected through
Monday evening outside a chance for scattered showers and
thunderstorms late Saturday into Saturday evening. Conditions
improve late Saturday night as a secondary cold front pushes
offshore and High pressure with drier air settles in with clearing
skies which should prevail into Monday evening. Moisture is
expected to increase across the area late Monday night and Tuesday
ahead of a retreating warm front. Associated showers and
Thunderstorms will produce periods of sub VFR conditions
especially Tuesday and beyond as the pattern becomes more active.
&&
.MARINE...
Short Term /through tonight/...
As of 300 PM Friday...S/SW winds are running 10-20 kt as the
pressure gradient tightens ahead of the front. winds in the
central outer waters are flirting with sca conditions but expect
them to be mostly below 25 kt sustained with perhaps a brief
period gusting to 25 kt. The front will move across the waters
this evening with winds becoming NW and diminishing to below 10
kt after midnight. NWPS and WW3 in good agreement with seas
3-5 ft this afternoon and evening then subsided to 2-4 ft after
midnight tonight.
winds become SW again during the day on saturday and increase to
10 to 15 KT during the afternoon ahead of a secondary strong cold
front that approaches late Saturday and crosses the waters
Saturday evening. By late afternoon SW winds will increase 15 to
20 kt Saturday possibly reaching 20 to 25 kt by Saturday evening
over the southern and central waters. seas will mostly run 3 to 5
feet during the afternoon but could see some 6 foot seas creep
into the outer central waters by late in the day. a brief Small
Craft Advisory may be needed for the central waters but will hold
off on issuing at this time.
Long Term /Saturday through Tuesday/...
As of 330 am Friday...The secondary strong cold front crosses the
waters Saturday evening. Ahead of the front SW winds will increase
15 to 20 kt Saturday possibly reaching 20 to 25 kt Saturday
evening over the southern and central waters. Behind the front the
winds will become northwest to north 15 to 20 kt strongest over
the northern and central waters late Saturday into early Sunday.
Seas will generally 3 to 5 ft through Sunday but 4 to 6 ft will be
possible Saturday night and early Sunday over the outer waters and
a brief Small Craft Advisory may be needed for the near shore
waters.
The flow is forecast to become westerly around 15 kt Sunday as
High pressure builds over the waters then become northerly around
15 kt Sunday night into Monday. Winds are forecast to veer around
to southeast Tuesday and increase to 15 to 20 kt as a warm front
approaches from the south. Seas are forecast to subside to 2 to 4
feet later Sunday and remaining low through Monday night before
possibly increasing to 4 to 6 ft late Tuesday.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...None.
MARINE...None.
&&
$$
SYNOPSIS...RSB
NEAR TERM...RSB
SHORT TERM...RSB
LONG TERM...JBM
AVIATION...JBM/SGK
MARINE...RSB/JBM
Area Forecast Discussion
National Weather Service Raleigh NC
255 PM EDT FRI MAY 13 2016
.SYNOPSIS...A weak cold front will move off the coast this evening,
followed by high pressure that will build briefly overhead tonight.
A much stronger cold front will cross the region Saturday evening.
High pressure will build in from the west Saturday night through
Monday.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 1120 AM Friday...
Update... Current forecast is in very good shape with little change
needed. The latest surface analysis from 14z shows the cold front
moving east of the southern Appalachians into the foothills with the
front reaching Shelby, Hickory and Mt Airy with improving sky
conditions. the air mass change lags behind the front with dew
points in the upper 50s just arriving at Morganton and Wilksboro.
As noted below, the two areas of showers or light rain continue to
progress northeast across central and eastern NC. High resolution
convection allowing models suggest that convection should begin
developing during the next couple of hours near the U.S. 1 region
and push northeast ahead of a prefrontal trough. This region is
characterized by dew points in the mid to upper 60s along with weak
but slowly increasing instability with MLCAPE values around 500
J/Kg. The scattered convection should expand and intensify as it
pushes east into the Sandhills and southern Coastal Plain during the
early to mid afternoon with MLCAPE values increasing to around 1000
J/Kg. A strengthening flow aloft should support bulk shear values
approaching 30 kts which will lead to some storm organization and a
limited severe threat focused on downburst winds. while the main
lines pushes out of the RAH CWA late this afternoon additional
isolated convection may develop in the Coastal Plain and Sandhills
region behind the prefrontal trough but ahead of the slowing cold
front. The RAP and NAM guidance note that the front and the drier
dewpoints may not reach the Sandhills until after midnight which
could support an isolated shower or storm across that area through
sunset and period of low stratus or fog into the early morning
hours.
Temperatures today will be complicated by precipitation, increasing
insolation behind the front in the western Piedmont where a
downslope flow will develop during the afternoon and breaks in the
overcast further east. The result will be a varied and localized
temperature trend with highs in most places reaching the lower 80s
at some point. lows tonight will fall back into the 50s. -blaes
Previous discussion... Around a mean mid-upper level low over
southern Manitoba, a lead shortwave trough now stretching from the
Upper Great Lakes to the Lower MS Valley will lift northeastward,
with an accompanying SSW`rly upper jet axis, into the Northeast and
Middle Atlantic States by this evening.
At the surface, a stationary front remains draped from central VA
to eastern NC, with an associated lingering cold air damming air
mass /low overcast and fog/ on the cool side of the front.
Overwhelming southerly flow in the low levels should hold this
boundary at bay from central NC, with a subsequent rapid
northeastward retreat through eastern VA early today. Upstream, a
trailing cold front now stretches across the eastern OH and TN
Valleys SW`wrd into eastern TX. This boundary, and preceding pre-
frontal trough now extending from the western Carolinas through
east-central GA, will move east across central NC today, with the
former likely to reach the NC Coastal Plain around sunset.
A band of showers --the remnants of earlier strong to severe
storms-- will continue to move northeast across the NC Coastal
Plain and southern Sandhills for the next few hours, in an axis of
relatively-focused moisture transport on the southern periphery
of an MCV parent to the band of showers.
Attention will then turn to the west, where an upstream band of
showers now near the NC Blue Ridge, will move eastward amidst the
leading edge of 30-40 meter mid level height falls accompanying
the aforementioned shortwave trough aloft, and into the NC
Piedmont between 12-16Z. A cool boundary layer and associated
negligible CAPE during that time suggests only light precipitation
and mid level ceilings will accompany this activity. Additional
showers and storms will then likely develop at the leading edge of
that associated cloud band, likely along the aforementioned pre-
frontal surface as it moves into the eastern Piedmont/Sandhills
and Coastal Plain, where diurnal timing there will favor moderate
destabilization characterized by MLCAPE on the order of 1000-1500
J/KG, as surface temperatures warm into the 70s.
Only modest SSW`rly mid level flow /30-35 kts/ on the eastern
periphery of the approaching trough aloft, suggests storm modes
will remain relatively disorganized, with perhaps some some
strong to marginally severe wind gusts accompanying multi-cell
line segments, generally between 17-22Z.
Diabatic heating /into the lower 80s/ will likely be stronger to
the west of the developing storms around the I-95 corridor, but a
significant veered/westerly low level flow behind the pre-
frontal surface trough, and falling surface dewpoints through the
50s, will mitigate deep convective potential behind the lead
activity along the trough. The exception may again be along and
east of I-95 around sunset, where lingering surface dewpoints in
the low 60s may provide for the re-development of isolated
showers or storms, before those too move east by mid-late evening.
Otherwise, a noticeably drier air mass will advect east tonight,
along with clearing skies, with lows in the 50s.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
As of 235 AM Friday...
The secondary cold front is still on target to push through our
region saturday afternoon. a very dry boundary layer will exist with
surface dew points likely only 50-55 or so in the pre-frontal
environment. Once the front passes, even drier and eventually cooler
air will surge into the region. We will maintain the 20 POP for an
isolated shower or thunderstorm in the northeast zones during the
afternoon. Otherwise, dry and warm SW-W winds 10-20 MPH will become
NW after the front passes. Highs generally 80 to 85 expected. Much
cooler air will arrive Saturday night with clear skies. Lows in the
45-53 range expected NW to SE. The winds will be gusty to 25 mph
during the evening, before diminishing to around 10 mph after
midnight.
&&
.LONG TERM /Sunday through Friday/...
As of 245 PM Friday...
Sun-Mon: Cool and dry. The polar cold front will have pushed to our
south by Sun morning, with thicknesses plunging to 40-50 m below
normal as cool high pressure builds into and over the area from the
west. Expect mostly clear skies Sun/Sun night. Highs around 10 deg F
below normal, in the upper 60s to lower 70s. Lows 44-50. Forecast
soundings do suggest the potential for orographically enhanced
cirrus cloudiness Sun night into early Mon morning, given the fast
mid-high level WNW flow increasing with height, improving moisture
aloft, and shearing mid level vorticity passing just to our north.
Regardless of this occurring or not, we should still see increasing
clouds through the day Mon as the mid level flow flattens and
becomes WSW with a weak wave crossing the lower Miss Valley late in
the day. Thicknesses rebound slightly after the chilly start,
supporting highs Mon from around 70 to the mid 70s.
Mon night through Tue night: The aforementioned shortwave trough
will cross the Deep South and Southeast Mon night and Tue. As the
surface high shifts off the NC/VA coast, the frontal zone just to
our south will edge back northward as a warm front, and the
increasing overrunning flow drawing both Atlantic and Gulf moisture
up and over the frontal zone should lead to widespread rain
development over NC. Confidence in the details is low due to
differences in timing and placement of best rain chances on both the
deterministic models and on ensemble members (the GEFS
specifically). But overall, rain chances will be increasing Mon
night through Tue, to good chance or likely, with perhaps a relative
lull Tue night as the departure of the weak wave as well as a
corresponding strengthening surface low coincides with diurnal
cooling and stabilizing. The GFS and ECMWF both appear to be
converging on a solution in which the front moves into northern NC
but stalls or dips back southward further into the state late Tue
into Tue night, nudged southward by the circulation around the
offshore-moving surface low, with a cool stable pool over northern
NC. after lows Mon night in the mid 50s to around 60, highs Tue
should reflect a smaller diurnal change, with highs from around 70
NW to the mid-upper 70s S. Lows Tue night 58-65 with clouds and
drizzle.
Wed through Fri: Trends favor continued unsettled weather with below
normal temps, as an active fast mid level WSW flow persists. The
frontal zone initially stretching across northern NC is expected to
be pushed southward into southern NC by dense high pressure, which
itself is reinforced by confluent flow aloft around a positively
tilted mid level low from the Canadian Maritimes across the Great
Lakes. The center of this surface high crosses the Great Lakes
region Wed before expanding eastward across the Northeast through
Fri, inducing a cold air damming event over our region. Given the
good model agreement and ensemble support, will retain considerable
clouds, above-climatology rain chances, and below normal temps for
this late-week period. -gih
&&
AVIATION /18Z FRIDAY THROUGH TUESDAY/...
As of 255 PM Friday...
a cold front extending southward across the western NC Piedmont early
this afternoon will advance east through this evening.
VFR conditions with SCT-BKN clouds are generally noted across
central NC with a few locations experiencing MVFR conditions in
prevailing lower CIGs across the Coastal Plain and/or accompanying
widely scattered showers or thunderstorms.
showers and thunderstorms will gradually become more numerous during
the afternoon, especially across the eastern Piedmont, Coastal Plain
and Sandhills with storms moving to the east and northeast. The vast
majority of the showers and storms will shift east out of the RAH CWA
late this afternoon and early evening. An isolated shower or storm
may re-develop around sunset near KFAY or KRWI behind the more
widespread convection with all of the precipitation over by 03z.
clearing skies should push southeast across the region this evening.
There are signals that low level moisture may be stubborn across the
Sandhills and southern Coastal Plain which could result in a period
of redeveloping stratus with IFR CIGs at KFAY and KRWI overnight,
especially after midnight. We have introduced a period of low stratus
after midnight at KFAY and KRWI. winds will become west to northwest
behind the front through the overnight hours at less than 10kts.
Winds will increase on Saturday from the west and become gusty up to
20kts by midday.
Outlook... Another cold front will approach the area on Saturday
afternoon with SCT-BKN cumulus with bases around 5-6kft. The front
will swing across central NC on Saturday evening. There is a small
chance of a brief VFR shower during the mid to late afternoon across
the north with dry weather and clearing skies on saturday night.
Gusty west winds on Saturday afternoon at 10 to 14kts with gusts of
20-25kts will become northwest on Saturday night. Generally fair
weather is expected through Monday with increasing chances of adverse
aviation conditions in scattered showers or thunderstorms on Monday
night into Tuesday. -blaes
&&
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...26/Hartfield
NEAR TERM...Blaes/26
SHORT TERM...Badgett
LONG TERM...Hartfield
AVIATION...blaes
AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
1251 AM CDT SAT MAY 14 2016
.UPDATE...
Issued at 1251 AM CDT Sat May 14 2016
Mid-level clouds are playing a pivotal role in temperature trends
tonight. For example, as of 05 UTC, Rolla is 27 F and Hettinger is
at 30 F, while Minot and Bismarck are still above 40 F at the same
time under a blanket of clouds based near 7000 ft AGL. Satellite
trends do show some holes in the cloud deck, so for now we merely
blended observed trends into hourly grids and have therefore left
the freeze warning in effect for the whole area.
UPDATE Issued at 931 PM CDT Fri May 13 2016
Freeze warning remains in effect after midnight tonight. Cold high
pressure will move over the region. however an area of cloud
cover north central will initially complicate the temperature
forecast as some clouds will likely remain well after midnight
north central. Minimum temperatures will still fall below
freezing tonight across the region and will leave the freeze
warning going. otherwise current forecast trending ok.
UPDATE Issued at 633 PM CDT Fri May 13 2016
For this update, the main issues are lingering strato-cu clouds
across northwest and southeast North Dakota. Skies are generally
clearing across the central. Updated the sky otherwise the current
forecast looks good.
&&
.SHORT TERM...(This evening through Saturday)
Issued at 246 PM CDT Fri May 13 2016
For the near term, the rest of this afternoon, low level lapse rates
remain conditionally unstable within the stratocumulus field across
central North Dakota. A passing brief shower is possible, but coverage
and brevity will preclude from mentioning within the gridded data.
Beginning to see a thinning of the clouds northwest and expect this
to gradually spread south and east this evening.
The main highlight is the freeze warning in effect tonight through
early Saturday morning, as overnight lows will range from the mid
20s to around 30 across western and central North Dakota. For the
most part, the stratocumulus field will continue to thin out along
with diminishing winds friday evening. However, mid clouds
already increasing ahead of our next shortwave Saturday are now
into central Saskatchewan. The GFS20 700mb-500mb RH field has a
good handle on clouds upstream, and these mid level clouds will
slide across the northern border around 06z Saturday, then spread
south overnight. Hence, our thinking is the freezing temperatures
north will occur near or around 06z, with steady or slowly rising
temperatures above freezing late tonight in the north central.
Elsewhere it will be cold overnight with lows in the mid 20s to
around 30 degrees. The coldest air will reside in southwest North
Dakota, in our normal cold spot at Hettinger where 25 degrees
looks good for now. A lack of clouds and winds will maximize
radiational cooling in southwest North Dakota.
The latest water vapor imagery shows a large cyclonic circulation
emanating from an upper low over southern Ontario. This continues
to draw down much cooler air via a north to northwest flow. Our
next mid to upper level shortwave was seen over the Nunavut
Territory of Canada which will shift south into central and
eastern North Dakota Saturday afternoon. Ahead of the shortwave,
increasing ascent indicated per Q-vector Divergence field over
central North Dakota with conditionally unstable low to mid level
lapse rates of 7C to 8.C/Km. This will lead to a chance of showers
Saturday afternoon and evening mainly along and east of highway 83.
The previous forecast had this covered well.
.LONG TERM...(Saturday night through Friday)
Issued at 246 PM CDT Fri May 13 2016
Departing shortwave and cold pocket Saturday night will lead to
widespread frost across western and central North Dakota, with a
possible freeze warning in the southwest.
For Sunday, after a cold start, temperatures will begin to moderate
by afternoon with highs in the 60s. It will be dry with surface
high pressure in place along with a mostly to partly sunny sky.
Monday through Friday, the dominant northwest flow gets shunted
east Monday and Tuesday as a building northern rockies ridge
nudges into western and central North Dakota. This ridge remains
in place into Friday with a warming trend through the extended
period. Highs will increase from the 60s Monday and Tuesday, into
the 70s Wednesday through Friday. Increasing southerly flow and
moisture will begin an upward tick for showers and thunderstorms
Thursday into next weekend.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1251 AM CDT Sat May 14 2016
VFR conditions will prevail tonight and Saturday, but some MVFR
ceilings are possible in far north central ND like around Rolla
on Saturday. A few showers may also impact central ND Saturday,
and northwest winds will gust up to around 25 kt at KMOT, KBIS,
and especially KJMS from late morning through the afternoon.
&&
.BIS Watches/Warnings/Advisories...
Freeze Warning until 9 AM CDT /8 AM MDT/ this morning for
NDZ001>005-009>013-017>023-025-031>037-040>048-050-051.
&&
$$
UPDATE...CJS
SHORT TERM...KS
LONG TERM...KS
AVIATION...CJS
Area Forecast Discussion
National Weather Service Bismarck ND
639 PM CDT FRI MAY 13 2016
.UPDATE...
Issued at 633 PM CDT Fri May 13 2016
For this update, the main issues are lingering strato-cu clouds
across northwest and southeast North Dakota. Skies are generally
clearing across the central. Updated the sky otherwise the current
forecast looks good.
&&
.SHORT TERM...(This evening through Saturday)
Issued at 246 PM CDT Fri May 13 2016
For the near term, the rest of this afternoon, low level lapse rates
remain conditionally unstable within the stratocumulus field across
central North Dakota. A passing brief shower is possible, but coverage
and brevity will preclude from mentioning within the gridded data.
Beginning to see a thinning of the clouds northwest and expect this
to gradually spread south and east this evening.
The main highlight is the freeze warning in effect tonight through
early Saturday morning, as overnight lows will range from the mid
20s to around 30 across western and central North Dakota. For the
most part, the stratocumulus field will continue to thin out along
with diminishing winds friday evening. However, mid clouds
already increasing ahead of our next shortwave Saturday are now
into central Saskatchewan. The GFS20 700mb-500mb RH field has a
good handle on clouds upstream, and these mid level clouds will
slide across the northern border around 06z Saturday, then spread
south overnight. Hence, our thinking is the freezing temperatures
north will occur near or around 06z, with steady or slowly rising
temperatures above freezing late tonight in the north central.
Elsewhere it will be cold overnight with lows in the mid 20s to
around 30 degrees. The coldest air will reside in southwest North
Dakota, in our normal cold spot at Hettinger where 25 degrees
looks good for now. A lack of clouds and winds will maximize
radiational cooling in southwest North Dakota.
The latest water vapor imagery shows a large cyclonic circulation
emanating from an upper low over southern Ontario. This continues
to draw down much cooler air via a north to northwest flow. Our
next mid to upper level shortwave was seen over the Nunavut
Territory of Canada which will shift south into central and
eastern North Dakota Saturday afternoon. Ahead of the shortwave,
increasing ascent indicated per Q-vector Divergence field over
central North Dakota with conditionally unstable low to mid level
lapse rates of 7C to 8.C/Km. This will lead to a chance of showers
Saturday afternoon and evening mainly along and east of highway 83.
The previous forecast had this covered well.
.LONG TERM...(Saturday night through Friday)
Issued at 246 PM CDT Fri May 13 2016
Departing shortwave and cold pocket Saturday night will lead to
widespread frost across western and central North Dakota, with a
possible freeze warning in the southwest.
For Sunday, after a cold start, temperatures will begin to moderate
by afternoon with highs in the 60s. It will be dry with surface
high pressure in place along with a mostly to partly sunny sky.
Monday through Friday, the dominant northwest flow gets shunted
east Monday and Tuesday as a building northern rockies ridge
nudges into western and central North Dakota. This ridge remains
in place into Friday with a warming trend through the extended
period. Highs will increase from the 60s Monday and Tuesday, into
the 70s Wednesday through Friday. Increasing southerly flow and
moisture will begin an upward tick for showers and thunderstorms
Thursday into next weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 633 PM CDT Fri May 13 2016
at 6 pm CDT, high pressure extended across eastern Montana with
low pressure over the Great Lakes region. Gusty northwest winds of
20 to 30 kts will diminish rapidly by 02z. VFR expected all TAF
locations.
&&
.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.
&&
$$
UPDATE...WAA
SHORT TERM...KS
LONG TERM...KS
AVIATION...WAA
Area Forecast Discussion
National Weather Service Grand Forks ND
306 PM CDT FRI MAY 13 2016
.SHORT TERM...(This evening through Saturday night)
Issued at 142 PM CDT Fri May 13 2016
Forecast challenges/impacts will be temperatures and pcpn chances
through the period. Region will be stuck in sharp cyclonic flow
into early next week with main challenge in timing of short waves
dropping through the trough bringing on and off again pcpn chances
to the region albeit light.
Current wave should complete its swing through the fa by early
evening. Canadian radar returns diminishing and high resolution
models have most pcpn done around 00z so will follow with pop
trends. Main issue will be widespread freezing temperatures
overnight. Guidance very consistent with minimum temperatures so
fairly high confidence in out come. clearing working into NW ND
and will continue to spread east behind departing mid level
trough. winds will also diminish somewhat allowing temperatures to
drop off. At this point freeze warning looks good.
Next impulse rotating around upper trough will impact parts of the
fa Saturday/Saturday night. Column warms slightly however
increasing clouds will hold max values well below average. Best
chances for pcpn look to be over the sw half of the fa.
Some light pcpn will linger into Saturday evening. Think there
will be enough residual cloud cover to minimize frost threat but
will have to monitor.
.LONG TERM...(Sunday through Friday)
Issued at 142 PM CDT Fri May 13 2016
Next wave slated for Sunday afternoon and Sunday night. This one
places best pcpn potential over ne half. Column warmer so pcpn
phase should be more liquid. Temperatures will continue to slowly
recover but still blo average.
Monday should be mainly dry with sub average temperatures
continuing.
Tuesday to Friday...Overall dry period with split flow once again
steering PCPN away from the Northern Plains. Only a slight chance at
the end of the forecast with 500mb southwesterly flow developing and
possibly a short wave lifting into the area. Temperatures will
slowly rise with highs in the mid 60s on Tuesday to mid 70s by
Friday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1249 PM CDT Fri May 13 2016
Winds and shower activity the main concern today. NW winds gusting
25 to 30kts this afternoon and slowly weakening this evening. CIGS
to be primarily VFR...4000ft to 5000ft...with SCT out expected
sometime overnight from west to east.
&&
.FGF Watches/Warnings/Advisories...
ND...Freeze Warning from midnight tonight to 9 AM CDT Saturday for
NDZ006>008-014>016-024-026>030-038-039-049-052>054.
MN...Freeze Warning from midnight tonight to 9 AM CDT Saturday for
MNZ001>009-013>017-022>024-027>032-040.
&&
$$
SHORT TERM...Voelker
LONG TERM...JK/Voelker
AVIATION...Voelker
Area Forecast Discussion
National Weather Service Bismarck ND
246 PM CDT FRI MAY 13 2016
.SHORT TERM...(This evening through Saturday)
Issued at 246 PM CDT Fri May 13 2016
For the near term, the rest of this afternoon, low level lapse rates
remain conditionally unstable within the stratocumulus field across
central North Dakota. A passing brief shower is possible, but coverage
and brevity will preclude from mentioning within the gridded data.
Beginning to see a thinning of the clouds northwest and expect this
to gradually spread south and east this evening.
The main highlight is the freeze warning in effect tonight through
early Saturday morning, as overnight lows will range from the mid
20s to around 30 across western and central North Dakota. For the
most part, the stratocumulus field will continue to thin out along
with diminishing winds friday evening. However, mid clouds
already increasing ahead of our next shortwave Saturday are now
into central Saskatchewan. The GFS20 700mb-500mb RH field has a
good handle on clouds upstream, and these mid level clouds will
slide across the northern border around 06z Saturday, then spread
south overnight. Hence, our thinking is the freezing temperatures
north will occur near or around 06z, with steady or slowly rising
temperatures above freezing late tonight in the north central.
Elsewhere it will be cold overnight with lows in the mid 20s to
around 30 degrees. The coldest air will reside in southwest North
Dakota, in our normal cold spot at Hettinger where 25 degrees
looks good for now. A lack of clouds and winds will maximize
radiational cooling in southwest North Dakota.
The latest water vapor imagery shows a large cyclonic circulation
emanating from an upper low over southern Ontario. This continues
to draw down much cooler air via a north to northwest flow. Our
next mid to upper level shortwave was seen over the Nunavut
Territory of Canada which will shift south into central and
eastern North Dakota Saturday afternoon. Ahead of the shortwave,
increasing ascent indicated per Q-vector Divergence field over
central North Dakota with conditionally unstable low to mid level
lapse rates of 7C to 8.C/Km. This will lead to a chance of showers
Saturday afternoon and evening mainly along and east of highway 83.
The previous forecast had this covered well.
.LONG TERM...(Saturday night through Friday)
Issued at 246 PM CDT Fri May 13 2016
Departing shortwave and cold pocket Saturday night will lead to
widespread frost across western and central North Dakota, with a
possible freeze warning in the southwest.
For Sunday, after a cold start, temperatures will begin to moderate
by afternoon with highs in the 60s. It will be dry with surface
high pressure in place along with a mostly to partly sunny sky.
Monday through Friday, the dominant northwest flow gets shunted
east Monday and Tuesday as a building northern rockies ridge
nudges into western and central North Dakota. This ridge remains
in place into Friday with a warming trend through the extended
period. Highs will increase from the 60s Monday and Tuesday, into
the 70s Wednesday through Friday. Increasing southerly flow and
moisture will begin an upward tick for showers and thunderstorms
Thursday into next weekend.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 246 PM CDT Fri May 13 2016
Breezy to windy conditions in a northwest surface flow this
afternoon and again Saturday afternoon. Low vfr ceilings to begin
the 18z taf period. Very isolated showers not significant enough to
mention in tafs. Expect ceilings to lift an thin as precip
diminishes through the day. An upper level impulse may bring an
isolated shower to kmot late Saturday morning.
&&
.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.
&&
$$
SHORT TERM...KS
LONG TERM...KS
AVIATION...TWH
Area Forecast Discussion
National Weather Service Grand Forks ND
1252 PM CDT FRI MAY 13 2016
.UPDATE...
Issued at 1249 PM CDT Fri May 13 2016
Snow showers or mix continues over all but the far west with
shortwave dropping through the forecast area. High resolution
model guidance gradually lessens coverage mid to late afternoon so
adjusted pops accordingly. Otherwise no other changes.
UPDATE Issued at 935 AM CDT Fri May 13 2016
Cancelled frost advisory. Weak radar returns continue roughly
across the NE half of the forecast area so maintained current
pops. Overall forecast good so no changes made.
UPDATE Issued at 636 AM CDT Fri May 13 2016
Rain and snow exiting far SE ND at 12z. Upper low moving east a
bit into far nw ontario and a short wave is dropping south and
then east with one short wave trough entering northeast MN into
the central RRV. a few very light showers with this. So did
expand the low pop for isold RW- to all of the RRV and much of nw
MN today. Interesting is behind this short wave is a bit of
clearing taking place in the past 1-2 hours. Upstream is another
short wave with associated clouds and snow showers in the
inter lake region of Manitoba. Will tweak sky cover a bit but
otherwise leave most things as is. Temps in the nrn tier of
counties in the 30-33 so will let the frost adv hold til
expiration at 14z.
&&
.SHORT TERM...(Today through Saturday)
Issued at 322 AM CDT Fri May 13 2016
500 mb short wave moving east-southeast as advertised and bringing
precipitation to areas along the South Dakota border. Temps
cooling with the precipitation turning the rain to snow in many
areas. Snow now at Forman DOT webcam. The mixed precip will exit
the far southern forecast area shortly after 12z. Today will be
dominated by gusty north winds as a secondary cold front which has
entered northeastern ND makes it way south early this morning. A
20-30kt 925 mb wind should mix down and 925/850 mb temps fall. So
recovery from morning lows will not be a whole lot. With clouds in
place as well and maybe a sprinkle shower, Expect high
temperatures a good 20 to 30 degrees below normal today.
Huge question tonight is temperatures and how low. short range
and global models insist it will clear out at least partially over
the forecast area. Even with clouds remaining the strength of the
cold air will allow temperatures to drop to below freezing. Just
how low is the question. If clearing then 25-28 more likely but if
cloudy more then 30-32 and this is a big difference to sensitive
plants/crops. will go ahead and issue the freeze warning for all
of the forecast tonight.
Saturday will see another short wave drop south in the afternoon
with the risk of a shower or two. A little warmer but still well
below normal.
.LONG TERM...(Saturday night through Thursday)
Issued at 322 AM CDT Fri May 13 2016
Any light precipitation will exit west central MN Saturday
evening. But another one fast on its heels for sunday afternoon to
bring another risk for a few showers. These systems are weak
moisture wise but just keep area in clouds and cool temperatures.
Though not as cool as today.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1249 PM CDT Fri May 13 2016
Winds and shower activity the main concern today. NW winds gusting
25 to 30kts this afternoon and slowly weakening this evening. CIGS
to be primarily VFR...4000ft to 5000ft...with SCT out expected
sometime overnight from west to east.
&&
.FGF Watches/Warnings/Advisories...
ND...Freeze Warning from midnight tonight to 9 AM CDT Saturday for
NDZ006>008-014>016-024-026>030-038-039-049-052>054.
MN...Freeze Warning from midnight tonight to 9 AM CDT Saturday for
MNZ001>009-013>017-022>024-027>032-040.
&&
$$
UPDATE...Voelker
SHORT TERM...Riddle
LONG TERM...Riddle/Speicher
AVIATION...Voelker
Area Forecast Discussion
National Weather Service Bismarck ND
1202 PM CDT FRI MAY 13 2016
.UPDATE...
Issued at 1202 PM CDT Fri May 13 2016
Previous forecast remains on track. Visible satellite imagery
shows a swath of stratocumulus clouds covering most of western
and central North Dakota. There will likely be some lifting and
thinning across the west this afternoon as low to mid level lapse
rates (850mb to 700mb) increase and mix with drier air aloft. Sky
grids from earlier had this handled well with partly cloudy
conditions developing, while keeping the central and east mostly
cloudy.
Have had a report of a quick snow shower in Minot, and surface
observation at Stanley showed a brief period of a rain or snow
shower. Local and regional radar indicates shallow, isolated
reflectivities, much like the HRRR composite reflectivity forecast
was indicating. Due to the brevity and coverage of these echoes,
will not add any pops to the grids but will monitor the trends for
any significant changes to the above thinking. Lapse rates remain
marginal in central North Dakota this afternoon, but increase in
the west as mentioned above.
With increased cloud cover, mixing heights have been interrupted
a bit from the Turtle Mountains south to the James River Valley,
enough to limit sustained winds below 30 mph sustained. Most
central reporting sites remain in the 20 to 28 mph sustained
environment. Thus will not issue any wind advisory headline at
this time.
UPDATE Issued at 914 AM CDT Fri May 13 2016
Frost advisory expired on time this morning. Current forecast on
track per latest HRRR sky and precipitation forecast. RAP Bufkit
winds indicate a borderline wind advisory in the James River
Valley with sustained to 30 mph. For now, will watch the sustained
winds over the next couple of hours before issuing any headline.
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 18Z TAFS through 18Z Saturday afternoon)
Issued at 1202 PM CDT Fri May 13 2016
Breezy to windy conditions in a northwest surface flow this
afternoon and again Saturday afternoon. Low vfr ceilings to begin
the 18z taf period. Very isolated showers not significant enough to
mention in tafs. Expect ceilings to lift an thin as precip
diminishes through the day. An upper level impulse may bring an
isolated shower to kmot late Saturday morning.
&&
.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.
&&
$$
UPDATE...KS
SHORT TERM...CJS
LONG TERM...CJS
AVIATION...TWH
Area Forecast Discussion
National Weather Service Phoenix AZ
424 AM MST SAT MAY 14 2016
.UPDATE...To Aviation Discussion...
&&
.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...
Upper level heights are slowly falling across the Desert Southwest as
the ridge axis is now shifting into New Mexico. Weak cyclonic flow
at 500mb is currently moving through Arizona with an influx of mid
level moisture accompanying this weak shortwave. Current water vapor
imagery shows this moisture quite well as well as IR imagery where
mid and high clouds are seen moving into Arizona from southern
California. These clouds will keep morning temperatures on the mild
side with lower 80s still present across the Phoenix area as of 09Z.
Another slight chance of high based showers or even a thunderstorm
will be possible just southeast of our CWA this afternoon before
drier air and the flow aloft turns more westerly. Highs today will
again be quite warm with little change to the airmass, but just shy
of Friday`s readings.
The 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...
Few passing weak weather systems ahead of a larger approaching low
pressure feature will generate mid-level cloudiness, ranging from
FEW to BKN at times, throughout the day. Enough moisture/humidity has
worked its way into the area to allow for even some remote chances
for virga to develop, mainly east of Maricopa County and the Phoenix
area terminals by the afternoon. Winds to follow typical diurnal
headings with speeds slightly elevated over the past few days, with
isolated afternoon gustiness possible as well.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
Monday through Friday...
A low pressure system centered over Idaho on Monday will dig
southward becoming centered over northwest AZ by Tuesday afternoon.
This will lead to a slight chance of thunderstorms Tuesday/Tuesday
night. The low will weaken Wednesday and move out Thursday. Breezy to
windy conditions develop Friday (mainly near and west of the Lower
Colorado River Valley) as another system approaches. Minimum
humidities will generally be in the 10-15 percent range on the lower
deserts (closer to 15% on Tuesday; closer 10% Thu-Fri). Overnight
recovery will be good early in the week then slowly decline.
&&
.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...AJ
Area Forecast Discussion
National Weather Service Phoenix AZ
930 PM MST FRI MAY 13 2016
.SYNOPSIS...
High pressure over the region is starting to weaken and signals a
change to slighly cooler temperatures and more breezy conditions for
the weekend. An approaching low pressure system will slowly drop down
into Arizona by Tuesday and help keep temperatures at or below normal
for a few days and even provide a chance for thunderstorms Sunday
through Tuesday.
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...
High pressure ridge axis is aligned over eastern Arizona right now.
Water vapor imagery shows an area of high clouds and upper level
moisture moving towards the northeast over the eastern part of the
state. Another surge of high level moisture is moving across southern
California. IR satellite indicates a closed low pressure system off
the northwest California coast.
The high pressure ridge is already beginning to weaken and slip
slightly towards the east. Pressures are expected to continue to drop
slowly through Sunday evening as the Pacific low pressure moves into
the northwest U.S. and exerts more influence over the western U.S.
For Arizona and southern California gradient will increase and thus
increase winds across the area as well as pull down some cooler air.
The breezy conditions will extend down to the surface leading to some
afternoon winds across Arizona both Saturday and Sunday. This should
be a dry system, not bringing any significant chance for rain at
least across our CWA. The low pressure system will stay entrenched
over the region for several more days and will produce at least one
short wave rotating around the low pressure. This will move into
Arizona late Monday into Tuesday. At the same time the low pressure
is progged to deepen and push south, increasing its influence over
the desert southwest. By Tuesday evening and Wednesday morning it
will even bring a chance for some rain and possibly thunderstorms---
at least over higher terrain. The low will finally pull out of the
region and weaken by Thursday but will leave us in zonal flow and
thus help keep us from getting under another high pressure ridge
pattern and helping hold temps down just a bit.
.PREVIOUS DISCUSSION...
Return flow around a ridge to our east predominates this afternoon,
which has helped to produce well-above normal temperatures but short
of records. Meanwhile, moisture continues to lift northward out of
Sonora ahead an anomalous trough evident in the upper-level
streamlines across the Gulf of California. Little impact from this
system is expected today or tonight. However, global models and CAMs
continue to suggest that the residual moisture will promote the
development of isolated convection Saturday. PoPs were consequently
increased (but remain below 10 percent) for Saturday morning and
afternoon, particularly from Phoenix eastward and across the higher
terrain. The increase in low- level moisture (mixing ratios up to
around 6 g/kg) and cloudiness will have an effect on temperatures and
highs were lowered roughly one degree from the previous forecast.
Nevertheless, temperatures will remain several degrees above average.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...SOUTHEAST
CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
A couple of weak weather disturbance ahead of an approaching low
pressure system will create some cloudiness above FL100 with possibly
some isolated virga the rest of the afternoon into Saturday. Areas
east of the Lower Colorado River Valley are most likely to be
affected (more so southeast AZ). Otherwise, expect familiar warm
season diurnal wind patterns (stronger tomorrow afternoon).
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
Monday through Friday...
A low pressure system centered over Idaho on Monday will dig
southward becoming centered over northwest AZ by Tuesday afternoon.
This will lead to a slight chance of thunderstorms Tuesday/Tuesday
night. The low will weaken Wednesday and move out Thursday. Breezy to
windy conditions develop Friday (mainly near and west of the Lower
Colorado River Valley) as another system approaches. Minimum
humidities will generally be in the 10-15 percent range on the lower
deserts (closer to 15% on Tuesday; closer 10% Thu-Fri). Overnight
recovery will be good early in the week then slowly decline.
&&
.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
Aviation...AJ
Fire Weather...AJ
[top]
Area Forecast Discussion
National Weather Service Flagstaff AZ
345 PM MST FRI MAY 13 2016
.SYNOPSIS...A Low pressure system off the west coast will bring
increasing southwest winds, cooling temperatures, and slight chances
for showers and thunderstorms this weekend. From Monday through
Thursday, the low pressure system will cross the state causing
better chances for showers and thunderstorms and near to slightly
below average temperatures.
&&
.DISCUSSION...High pressure over Arizona peaked today and will start
to move east tonight as a low pressure system approaches the West
Coast. Increasing mid and high level moisture from the south brought
a few light showers to southern Apache County this afternoon.
On Saturday, the high pressure will continue to move east as the low
off the West Coast moves eastward. This will bring a cooling trend,
increasing southwest winds, and increasing moisture. Isolated high
based showers and thunderstorms will be possible over higher terrain
-primarily along and north of the Mogollon Rim on Saturday. By
Sunday, the approaching low pressure system will bring strong
southwest winds across much of northern Arizona. The strongest winds
are expected across central and southern Navajo and Apache counties,
where wind gusts exceeding 40 mph are possible.
From Monday through Thursday: The upper level low will move
southward on Monday before crossing Arizona on Tuesday and
Wednesday. This will lead to increasing chances for precipitation
and near to slightly below average daytime temperatures. On Monday,
there are slight chances for showers and thunderstorms, primarily
along and north of Interstate 40. On Tuesday and Wednesday, better
chances for showers are expected across all of northern Arizona as
the low passes over the state. By Thursday, the low is expected move
eastward into New Mexico with lingering showers and thunderstorms
along the Arizona and New Mexico border.
&&
.AVIATION...For the 00Z package...Expect SKC-SCT skies through 18Z
Saturday, though east of KSOW may be the exception with a slight
chance of showers tonight. Slight chance for showers spread to much
of northern Arizona after 18Z Saturday. Light winds overnight will
turn southwesterly and breezy after 18Z Saturday as well. Aviation
discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Southwest winds will increase on Saturday as a
trough builds into the southwest United States, along with the
threat of isolated high-based afternoon thunderstorms. Generally dry
conditions are forecast for Sunday, though southwest winds will
strengthen that day leading to near critical fire weather
conditions.
Monday through Wednesday...Increasing chances of afternoon
thunderstorms along with cooler daytime temperatures are expected as
low pressure settles into the region.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...MAS
AVIATION...KD
FIRE WEATHER...KD
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Phoenix AZ
327 PM MST FRI MAY 13 2016
.UPDATE...
Updated Aviation and Fire Weather sections.
&&
.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...
Return flow around a ridge to our east predominates this afternoon,
which has helped to produce well-above normal temperatures but short
of records. Meanwhile, moisture continues to lift northward out of
Sonora ahead an anomalous trough evident in the upper-level
streamlines across the Gulf of California. Little impact from this
system is expected today or tonight. However, global models and CAMs
continue to suggest that the residual moisture will promote the
development of isolated convection Saturday. PoPs were consequently
increased (but remain below 10 percent) for Saturday morning and
afternoon, particularly from Phoenix eastward and across the higher
terrain. The increase in low- level moisture (mixing ratios up to
around 6 g/kg) and cloudiness will have an effect on temperatures and
highs were lowered roughly one degree from the previous forecast.
Nevertheless, temperatures will remain several degrees above average.
&&
.PREVIOUS DISCUSSION...
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...
A couple of weak weather disturbance ahead of an approaching low
pressure system will create some cloudiness above FL100 with possibly
some isolated virga the rest of the afternoon into Saturday. Areas
east of the Lower Colorado River Valley are most likely to be
affected (more so southeast AZ). Otherwise, expect familiar warm
season diurnal wind patterns (stronger tomorrow afternoon).
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
Monday through Friday...
A low pressure system centered over Idaho on Monday will dig
southward becoming centered over northwest AZ by Tuesday afternoon.
This will lead to a slight chance of thunderstorms Tuesday/Tuesday
night. The low will weaken Wednesday and move out Thursday. Breezy to
windy conditions develop Friday (mainly near and west of the Lower
Colorado River Valley) as another system approaches. Minimum
humidities will generally be in the 10-15 percent range on the lower
deserts (closer to 15% on Tuesday; closer 10% Thu-Fri). Overnight
recovery will be good early in the week then slowly decline.
&&
.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
[top]
Area Forecast Discussion
National Weather Service Tucson AZ
245 PM MST FRI MAY 13 2016
.SYNOPSIS...
Strong high pressure aloft will bring well above average
temperatures Saturday. There is also enough moisture for a slight
chance of showers and thunderstorms from Tucson eastward Saturday
afternoon. A storm system moving north of the area will then bring
gusty winds Sunday followed by cooler temperatures early next week.
&&
.DISCUSSION...Partly cloudy to mostly cloudy skies across southeast
Arizona this afternoon as fairly thick cirriform clouds move
northeastward across the area. Some cumuloform clouds were also
noted across the White mountains and near the New Mexico border as
per visible satellite imagery. Have maintained a slight chance of
showers and thunderstorms thru this evening mainly near the
International border south-to-southeast of Tucson, and across far
eastern sections. Dry conditions are then expected late tonight into
Saturday morning.
Southwesterly flow aloft will prevail Saturday afternoon ahead of a
low pressure system moving eastward into the Pacific NW. 13/12Z Univ
of AZ WRF-NAM and WRF-GFS were quite similar with developing
showers/thunderstorms mainly near the Catalina/Rincon mountains near
Tucson early Saturday afternoon. These showers/thunderstorms are
then depicted to expand in coverage while moving newd across ern
sections Saturday afternoon and early Saturday evening. These
solutions are more similar to the 13/12Z ECMWF versus the drier GFS.
Thus, the official forecast depicts a slight chance of showers/tstms
from near the Tucson metro area eastward to the New Mexico border
Saturday afternoon/evening. Dry conditions are then expected
Saturday night-Monday night. However, a tight mid-level gradient
will translate into gusty southwest winds Sunday afternoon. Wind
advisory criteria may be achieved Sunday afternoon for locales
southeast of Tucson. Somewhat less wind will occur Monday.
GFS/ECMWF were similar with deepening an upper trough over the Great
Basin/Intermountain west/southwestern CONUS Tue-Wed. The ECMWF was
markedly more robust with liquid amounts versus the GFS. At any
rate, There is a chance of showers/tstms Tue afternoon/evening
mainly across the White mountains. Have included a slight chance of
showers/tstms for eastern sections Wednesday. A drying trend should
commence Wed night as the mid-level trough axis moves east of the
area. Still enough moisture for a slight chance of showers/tstms
across the White mountains Wed night-Thur. Dry conditions are then
expected to prevail Thur night-Fri under wly/swly flow aloft.
High temps Sat will be quite similar to temps achieved this
afternoon followed by about 5 degs or so of daily cooling Sun-Mon.
High temps Tue-Wed will be below normal, then a pronounced warming
trend is on tap Thur-Fri.
&&
.AVIATION...VALID THRU 15/00Z.
Expect isolated -TSRA/-SHRA near the Mexico and New Mexico border
thru 14/04Z otherwise sct-bkn clouds above 20k ft thru much of
tonight. After 14/19Z isold-sct -TSRA/-SHRA developing with sct to
locally bkn 10k ft clouds. Surface wind through 14/03Z will be
wly/nwly at 10-15 kts then becoming variable at less than 10 kts.
Wind becoming SW 9-16 kts Saturday afternoon. Aviation discussion
not updated for TAF ammendments.
&&
.FIRE WEATHER...Any convection that develops through this evening
should remain limited to the Mexico and New Mexico border. However
moisture will increase later tonight and Saturday enough to bring a
threat of showers and thunderstorms from the Tucson area eastward
Saturday afternoon and early evening. Any storms that develop
Saturday will move to the east-northeast.
A strong upper level trough will approach the region Sunday forcing
drier air over the area on gusty southwest winds. At this time it
looks like a significant portion of fire zones 151 and 152 will
reach critical fire weather conditions Sunday afternoon.
Therefore I have issued a Fire Weather Watch for the southern 2/3rds
of both zones for late Sunday morning into early Sunday evening.
Dry but cooler conditions will prevail Monday followed by a slight
chance of showers and thunderstorms Tuesday into Wednesday, mainly
north. Thursday and Friday will be warm and dry with less wind.
&&
.TWC Watches/Warnings/Advisories...
Fire Weather Watch from Sunday morning through Sunday evening
for AZZ151-152.
&&
$$
Discussion...Francis
Aviation/Fire Weather...Cerniglia
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
Area Forecast Discussion
National Weather Service Phoenix AZ
221 PM 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...
Return flow around a ridge to our east predominates this afternoon,
which has helped to produce well-above normal temperatures but short
of records. Meanwhile, moisture continues to lift northward out of
Sonora ahead an anomalous trough evident in the upper-level
streamlines across the Gulf of California. Little impact from this
system is expected today or tonight. However, global models and CAMs
continue to suggest that the residual moisture will promote the
development of isolated convection Saturday. PoPs were consequently
increased (but remain below 10 percent) for Saturday morning and
afternoon, particularly from Phoenix eastward and across the higher
terrain. The increase in low- level moisture (mixing ratios up to
around 6 g/kg) and cloudiness will have an effect on temperatures and
highs were lowered roughly one degree from the previous forecast.
Nevertheless, temperatures will remain several degrees above average.
&&
.PREVIOUS DISCUSSION...
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 Flagstaff AZ
945 AM MST FRI MAY 13 2016
.SYNOPSIS...High pressure over northern Arizona will lead to another
warm day, with high temperatures around 10 degrees above average.
Limited moisture will bring a slight chance of thunderstorms to the
White Mountains this afternoon. An approaching low pressure system
will cause increasing southwest winds, cooling temperatures, and
slight chances for showers and thunderstorms over higher terrain
over the weekend. From Monday through Thursday, the low pressure
system will cross the state causing better chances for showers and
thunderstorms and near to slight below normal temperatures.
&&
.DISCUSSION...Increasing mid and high level moisture from the south
today will bring a slight chance of high based showers and
thunderstorms to the White Mountains today. The leading edge of this
moisture is seen in the form of high clouds moving into southern
Arizona this morning. Will update the forecast for Northern Gila,
Eastern Mogollon Rim, and White Mountains today and this evening.
&&
.PREV DISCUSSION /425 AM MST/...For today: A ridge of high pressure
in place across northern Arizona will lead to the warmest
temperatures of the year so far. In general, high temperatures are
forecast to be around 10 degrees above normal. In addition, expect
mostly clear skies, dry weather and relatively light winds. An
exception to this may be in the White Mountains region where a
slight chance for high based showers and thunderstorms is forecast.
For the weekend: While Saturday is expected to be another warm
day, the upper level ridge axis shifts eastward with the approach
of a Pacific low pressure system. This will result in the
beginning of a slow cooling trend and increasing southwest winds.
In addition, enough low and mid level moisture may be drawn
northward into the region for isolated high based showers and
thunderstorms over higher terrain - primarily along and north of
the Mogollon Rim. By Sunday, the approaching low pressure system
is forecast to cause strong southwest winds across much of
northern Arizona. The strongest winds are expected across central
and southern Navajo and Apache counties, where wind gusts
exceeding 40 mph are possible.
From Monday through Thursday: The upper level low is forecast to
dive southward on Monday before crossing Arizona on Tuesday and
Wednesday. This will lead to increasing chances for precipitation
and near to slightly below normal daytime temperatures. On
Monday, slight chances for showers and thunderstorms are forecast,
primarily along and north of Interstate 40. On Tuesday and
Wednesday, better chances for showers are forecast across all of
northern Arizona as the low passes over the state. By Thursday,
The low is forecast to move eastward into New Mexico with
lingering showers and thunderstorms possible along the Arizona and
New Mexico border.
&&
.AVIATION...For the 18Z package...Expect VFR conditions
for the next 24 hours with occasional southwesterly breezes this
afternoon. Aviation discussion not updated for TAF amendments.
&&
.FIRE WEATHER...A high pressure ridge will remain over the
area today with above normal high temperatures...followed by an
approaching low pressure trough on Saturday. Southwest winds will
increase on Saturday, along with the threat of isolated high based
afternoon thunderstorms.
Sunday through Tuesday...Low min Rh`s on Sunday and very windy
afternoon conditions will lead to near critical fire weather
conditions. Monday and Tuesday, increasing chances of afternoon
thunderstorms are expected as low pressure moves on by.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...MAS/RR
AVIATION...KD
FIRE WEATHER...TC
For Northern Arizona weather information visit
weather.gov/flagstaff
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 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