Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/03/18
Area Forecast Discussion
National Weather Service La Crosse WI
647 PM CDT Sat Jun 2 2018
.SHORT TERM...(This evening through Sunday)
Issued at 200 PM CDT Sat Jun 2 2018
02.19Z water vapor loop shows a well-defined short-wave across
the Dakotas into western MN/IA. At the surface, a tight
circulation sits over southern Manitoba with a trough axis
extending southward along the Red River Valley and into west-
central MN. This trough will swing across the region later this
afternoon and evening as the wave aloft lifts northeastward. A
50-60 kt wind max between 500 and 300 hPa will rotate through the
region this evening, resulting in deep layer shear around 50 kts.
However, overcast skies have really put a damper on the amount of
available instability for thunderstorm development. Latest SPC
mesoanalysis shows a narrow axis of MUCAPE around 500 J/kg across
the area, but little in the way of SBCAPE or MLCAPE.
Think the lack of strong instability will limit widespread
thunderstorms and like the latest convective evolution from the
ESRL HRRR which suggests more scattered activity moving from west
to east through the evening. That said, most areas are likely to
at least see some showers as the trough moves through the area, so
higher end POPs still look reasonable. Cannot rule out a stronger
storm or two, especially if there is some clearing/late afternoon
heating, but overall confidence is low. Latest SPC Convective
Outlook looks good, pushing the marginal threat for severe
convection just east of the forecast area.
Expect some clearing overnight, mainly for areas west of the
Mississippi River. Cloud cover likely to hold tough across WI.
Temperatures will drop into the 50s for most locations and with
dewpoints falling into the upper 40s and lower 50s, it will be
quite comfortable.
.LONG TERM...(Sunday night through Saturday)
Issued at 200 PM CDT Sat Jun 2 2018
Sunday looks to be a quiet, dry, but fairly windy day with 30+ kt
winds in the mixed layer and a tight pressure gradient behind the
departing cold front and precip. Could easily see gusts approaching
30 kts in open areas of southeast Minnesota and northeast Iowa.
High temperatures on Sunday will be similar to today - in the mid
60s to mid 70s.
Breezy conditions will continue on Monday as high pressure continues
to build into the area. However, winds will shift to more westerly
(as opposed to northwesterly on Sunday) as a surface ridge axis
moves over the area by Sunday evening. As a result, temperatures
will be a bit warmer, with highs in the mid 70s to lower 80s. The
GFS has been persistent with convection over the forecast area
Monday night (while other models remain dry), but has also been way
too high with dewpoints, so thinking the chances for this
convection occurring are pretty low. That said, most guidance does
depict a pretty good short wave sliding just east of the area, so
thinking leaving some low end PoPs into early Tuesday makes
sense.
Upper level ridging will then amplify northward for the middle
and latter parts of the work week. Models in fairly good agreement
of a general pattern of shortwaves coming over the ridge leading
to shower and storm chances. That said, not much agreement in
timing for any given system, so forecast confidence is pretty low.
Looking at temperatures, given upper level ridge amplification
and 850 mb temperatures in the mid to upper teens, a warmup is on
tap, with highs in mid 70s to mid 80s. That said, temperatures
could vary a bit any given day depending on aforementioned
precipitation chances and associated cloud cover.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 647 PM CDT Sat Jun 2 2018
Scattered showers and thunderstorms will end by 03Z. Until then,
MVFR to IFR conditions are possible at KLSE in rain and possibly
an isolated thunderstorm. Then VFR conditions are expected
overnight but MVFR stratus looks to return Sunday morning in the
15 to 19 Z timeframe before becoming scattered during the
afternoon hours. Look for winds to increase out of the northwest
on Sunday to 17 to 20 kts with gust around 27 kts possible at
times.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...Rogers
LONG TERM...CA
AVIATION...Wetenkamp
Area Forecast Discussion
National Weather Service Denver/Boulder CO
856 PM MDT Sat Jun 2 2018
.UPDATE...
Issued at 856 PM MDT Sat Jun 2 2018
Clear skies and a dry airmass prevail across the forecast area.
From the latest GOES imagery and HRRR smoke output, we should see
at least some smoke aloft reach the forecast area by morning, and
possibly some in the lower levels as far north as the Palmer
Divide by morning. Forecast on track with good radiational cooling
tonight, then an increase in moisture and lift later tomorrow for
a few afternoon showers and storms.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 154 PM MDT Sat Jun 2 2018
Water vapor satellite imagery showing a low spinning northeast
across Arizona. This low will continue to lift northeast tonight
and Sunday. Mostly clear skies will persist through most of the
night. High clouds will spread into the area around sunrise with
the approach of the low. This low will bring scattered showers and
thunderstorms to the mountains Sunday. Isolated to scattered
convection will spread onto the Front Range and near by plains
late Sunday afternoon. Instability will be on the low side with
CAPE generally less than 500 J/kg. Dew points stay in the 40s,
however precipitable water values climbs to around three-quarters
of an inch across the Front Range and over the eastern plains. The
storms should be high based due to the low dew points, so expect
gusty winds, brief heavy rain, and small hail to accompany the
stronger storms.
Good radiational cooling tonight will allow temperatures to fall
into the 40s over most of northeast Colorado. In the mountain
valleys, 30s are expected. It will be slightly warmer Sunday with
highs in the low 80s across northeast Colorado. Increasing clouds
will slow heating during the afternoon.
.LONG TERM...(Sunday night through Saturday)
Issued at 317 PM MDT Sat Jun 2 2018
Models have a weak upper trough move across the CWA Sunday night.
There is upper ridging over Colorado Monday through Tuesday
night. There is some weak upward vertical velocity for the
forecast area on the QG Omega fields Sunday evening, then weak
downward energy is progged Monday and Monday night. There is
benign energy progged Tuesday and Tuesday night. Moisture is not
great, dew points are generally in the 30s to mid 40s F much of
the time from Sunday night through next Saturday. There are a few
lower 50s f near the eastern border. There is some minor CAPE
around Sunday evening. Late day on Monday, there is minimal CAPE
to none for most of the CWA, the values are near 1000 J/kg near
the eastern border. There is better coverage of the CAPE late day
Tuesday, with the highest values near the eastern border. For
pops, will go with "scattered" for the western half of the CWA
Sunday evening and isolated over the east. For the rest of the
week, the pops will be sparse. Temperatures will be at a bit above
90 for highs over the plains Monday and Tuesday. For the later
days, Wednesday through Saturday, there is an upper ridge axis
just to the east of Colorado with weak southwesterly flow aloft.
Moisture will be lacking and temperatures will remain above
seasonal normals.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 856 PM MDT Sat Jun 2 2018
Easterly winds around 10 knots will slowly turn southeast and
eventually southerly overnight at KDEN and KAPA. There may be thin
smoke layer aloft by Sunday morning, but at this time, not enough
to reduce horizontal visibilities under 10 miles. There is a 20%
chance of thunderstorms after 21Z Sunday, with a higher
probability of gusty outflow winds to around 35 knots.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Barjenbruch
SHORT TERM...Meier
LONG TERM...RJK
AVIATION...Barjenbruch
Area Forecast Discussion
National Weather Service State College PA
1150 PM EDT Sat Jun 2 2018
.SYNOPSIS...
A cut off upper low will linger over the Mid Atlantic region
through Sunday. The upper low will lift out late Sunday and
Monday as a stronger upper trough moves in from the west. That
longer-wave trough will hang over eastern Canada and the NE
CONUS for a good part of next week. These features will keep
some showers around the area from time to time, but next week
will be less humid overall.
&&
.NEAR TERM /UNTIL 7 AM SUNDAY MORNING/...
Busy night with little time to write thinking. Main points are
that the latest CAMs, NAM and even hints from GFS 18Z renew
convection overnight in the SC Cos. The constant train of
thunderstorms moving in from Philly are a great concern, as
these may go directly over the same areas which are experiencing
flash flooding now, and did last night as well. This rain would
only exacerbate any current flooding/high water, but make new
trouble. This is the reason for the expansion of the FFA done
earlier in the evening. The rain/flash flooding in Fulton Co,
and heavy rains of the past couple of days in Franklin, Bedford
and Somerset make them ripe for flash flooding as well with as
little as 1 inch of rain in an hour in Fulton Co, and 1.5
inches/hr in the rest of the watch area.
Prev...
Isolated showers are spread across my southern tier in the high
moisture environment and diurnal heating release instability
under the influence of weak forcing aloft as 578 dm 500 mb low
center drifts south of the Mason Dixon line.. Decent cell
motions to the SSW initially and best sfc moisture flux over MD
and VA this afternoon, and LLVL winds from the north are
pooling highest PW and sfc dewpoints south of the Mason Dixon
line. Deep layer PW conts to decrease across all but the
southern tier of central PA which is holding steady between
1.75" and 1.9". Sfc moisture flux from the HRRR is most
pronounced south of the Mason Dixon line this afternoon, and
expect most of the heavy rainers to occur south of my counties
over MD and northern Virginia during the afternoon.
However, towards evening moisture flux increases dramatically
over the Lower Susq with PW increasing to around 2"+ near the MD
border. This as LLVLs respond to increasing easterly flow around
northern New England high and sfc low over the Chesapeake
Region. Potential for heavy rainers to once again move over my
southeast counties and especially Lancaster/York counties is
greatest from late afternoon through late evening as a result.
Based on already very wet ground and latest CAMS, will maintain
flash flood watch for Adams, York and Lancaster counties for
this afteroon through 06Z Sunday. Northerly flow should advect
enough drier air into northern PA to keep at least partial
clearing north of I80...and just slight chc mentions over the
central mountains.
Heavy rain threat over the far south/southeast persists through
late tonight before the combination of a moist easterly flow
and an approaching mid level trough over the Grt Lks leads to
an increasingly wet forecast Sunday morning and more stable low
levels.
&&
.SHORT TERM /7 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
Did lower temps during the day Sun with little sunshine expected
and a E-SE fetch into the region from the Ocean and very wet
land masses of MD/DE/Srn NJ. Early convection may also cause
problems in the SWrn cos, and any instability along the western
border (where there could be a little sunshine break through)
would fire more convection. With the PWATs still high, flooding
may be of concern for areas even north of the watch area. Will
allow later shifts to chew on that possibility.
Prev...
Deep layer moisture gradually increases on Sunday with the heavy
rain threat slowly decreasing as a result, but cloud cover and
deep easterly flow will make for a soggy and cool Sunday for
most. Temperatures will be held well below seasonal norms
Sunday with maxes only in the 60s.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
Made only minor changes to the package.
Abnormal weather pattern this spring will continue to prevail.
Very cold and dry air to the north this morning will continue
to try to work into the area early next week. As the upper lvl
low lifts northeast on Monday, the chance of showers should
decrease later on Monday.
A strong jet max dropping southeast later Tuesday will result
in more showers and storms.
The best chance of dry conditions will be Wednesday into
Thursday, as weak high pressure works into the area.
Another cold front drops southeast on Friday, thus a chance
of showers and storms.
Next Saturday, went with the superblend. Some chance of showers.
EC supports a weak low dropping into the lee side low, a long
ways out, but in the area that often trys to balance the energy
balance of the earth, thus some support for a winter type low
forming. New EC shows a significant cool down behind this system.
Not a good thing, given how wet things have been this spring.
&&
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
Showers and thunderstorms continue to move through far
southeastern PA. MVFR will continue at BFD, AOO and UNV and
with the copious amounts of low level moisture cannot rule out
periods of MVFR to IFR at LNS. Mainly MVFR overnight with IFR at
BFD likely. Expect improving conditions late Sunday morning.
However another round of showers will again drop cigs and vsbys
Sunday afternoon.
.Outlook...
Mon...Patchy AM fog, then ceiling restrictions likely.
Tue-Wed...Patchy AM fog.
Thu...Patchy AM fog. Chc afternoon shra.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch until 10 AM EDT Sunday for PAZ033>036-
064>066.
&&
$$
SYNOPSIS...DeVoir/Martin
NEAR TERM...Dangelo
SHORT TERM...DeVoir/Fitzgerald
LONG TERM...Martin
AVIATION...DeVoir/Ceru/Tyburski
Area Forecast Discussion
National Weather Service Grand Forks ND
959 PM CDT Sat Jun 2 2018
.UPDATE...
Issued at 959 PM CDT Sat Jun 2 2018
Model sounding indicated cold advection was centered in the 850 to
925 hpa layer. Cold advection keeps the lower layer adiabatic with
25 to 35 knots to mix down overnight.
Plenty of rain/showers upstream over southern MAN. Showers were
dissipating from the west. However precip was developing over
northeast ND on west edge of 700 hpa trowal. Will increase pops over
northwest MN for the overnight.
Wind advisory expired at 9 pm cdt. However winds will remain up
tonight.
UPDATE Issued at 656 PM CDT Sat Jun 2 2018
Tweaked temps, dewpoints, winds and pops for tonight. Otherwise
little change at this update.
&&
.SHORT TERM...(This afternoon through Sunday)
Issued at 325 PM CDT Sat Jun 2 2018
Surface low pressure is centered over southern Manitoba, while
trough extends across the Red River Valley. Circulation on WV
imagery over the International Border matches location of H7 low
on RAP analysis, with deformation band apparent on IR/WV/Regional
Radar beginning to extend towards our NW CWA. Additional
showers/iso t- storms is transitioning east of our CWA, with
dry/subsident region centered over the RRV beginning to fill in on
satellite. Surface analysis shows pressure rises over north
central ND and upstream obs near our western CWA have been near or
above Wind Advisory criteria (gusts to 45mph or higher).
This afternoon-tonight: As upper low transitions eastward
deformation band should progress over our CWA, as well as
CAA/good pressure rises. Good pressure rises are expected in our
northwest and with showers possibly helping with momentum transfer
we should see advisory winds and Wind Advisory was kept in place.
I am still not sure how far east this threat would be as peak
pressure rises/winds aloft correlate with likely period of
decoupling after 00Z. I think we still need to monitor this, but I
wasn`t confident enough at expand ongoing advisory.
Limited instability and dry/subsident air has limited precip over
a lot of our CWA today (despite some CAMs showing otherwise).
There could still be a period of scattered showers (maybe an
isolated thunderstorm) later this afternoon through this evening
as this deformation zone transitions over our CWA and CAMs are
supporting increasing trends. Recent trends in radar/satellite
have lowered confidence in measurable (sprinkles may be favored),
so I did delay and undercut PoPs earlier than CAMs would indicate.
Trend on latest guidance is to slow down exit of precip tonight,
possibly lingering into Sunday morning in our far east.
Sunday: Ridging builds back over the region Sunday and dry
conditions return. As surface high pressure slides east we
should see WAA from our west and temperatures near seasonal
normals in the 70s across the RRV and locations west. Temperatures
in our east should be in the upper 60s closer to the surface high
center, but if low clouds linger (possible) this could limit this
further.
.LONG TERM...(Sunday night through Saturday)
Issued at 325 PM CDT Sat Jun 2 2018
Upper level ridging moves in Monday bringing dry
conditions with surface high pressure to the south. Overnight into
Monday there is still a chance for showers and thunderstorms to
develop as a warm front develops over Minnesota and North Dakota.
By Tuesday we will begin to see a mid level short wave trough push
through the Northern Plains. A surface low pressure is expected to
move through the Dakotas Tuesday into Wednesday which will increase
shower and thunderstorm chances. There is some indication of a
severe weather potential due to the CAPE/Shear environment, but
confidence is still low at this point. At the moment, areas more
likely to see the strong storms will be along the warm front within
MN late Tuesday followed by the cold front approaching from the west
into Wednesday. Precipitation chances will then begin to diminish by
late Wednesday as the cold front pushes east towards the northern
Great Lakes Region.
By Thursday high pressure then fills back in behind the cold front.
As the high pressure tracks eastward southerly winds will return
moisture back to the area allowing for shower and thunderstorm
chances to return into Friday. Current forecast shows above normal
temperatures by the start of the weekend. Going into the weekend,
guidance suggests a deep disturbance will develop in the Pacific
Northwest which may influence our weather over the Northern Plains.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 656 PM CDT Sat Jun 2 2018
Satellite indicated a cloudy sky across the area with a few breaks
in the ovc. MVFR cigs remain over the north and far east zones. Some
IFR cigs were located over the far northeast zones. Expect MVFR
conditions over the MN side of the Red River overnight. Clearing
should occur from the west on Sun. IFR conditions over the far
northeast may expand south over the far eastern zones overnight then
shift east of the area Sun morning. VFR condition expected Sun
aftn.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&
$$
UPDATE...JH
SHORT TERM...DJR
LONG TERM...AH/CJ
AVIATION...JH
Area Forecast Discussion
National Weather Service Fort Worth TX
708 PM CDT Sat Jun 2 2018
.UPDATE...
Heat index values will hover around 105F through nightfall, then
continue to fall as a cold front arrives later this evening. As
such, we`ll allow the Heat Advisory to expire at 7 pm as insolation
wanes. As for storm chances tonight, CAMs all have varying coverage
with the 3km NAM/NSSL WRF the most rambunctious of the group.
These models indicate scattered coverage of storms later this
evening from Dallas northeast and eastward, with more isolated
coverage further west which will be furthest away from the mid-
level shortwave and associated large-scale ascent moving through
Arkansas and toward the Ark-La-Tex into the Lower Mississippi
Valley.
Though effective bulk shear is shown to be only around 30 knots,
instability both at the surface and aloft will be high with
inverted-V lower profiles and plentiful dry air aloft. Current
upper air does indicate warmest temperatures a little further
aloft at 16.3 Deg C around 715mb, so there still some inhibition
around and it will be interesting to see how far west scattered
storms can zip down the cold frontal boundary later this evening.
The environment is primed for severe downbursts if deep updrafts
can root themselves to the near surface-layer. With near 8 Deg
C/KM, which is very steep does suggest that large hail will be
possible as well with a large positive area within the hail growth
zone aloft defined by the -10 Deg C to -30 Deg C layer. As of
now, current forecast looks reasonable with regard to all these
features, timing, and potential storm coverage.
05/
&&
.AVIATION...
/00z TAFs/
Made only minor adjustments to previous TAFs, as a cold front
continues to sag southward toward northern parts of the DFW Metro.
We expect the arrival of cold FROPA between 02z-03z across DFW,
then between 08z-10z at Waco. The FROPA push should pick up speed
as it receives support from a mid level shortwave disturbance
moving southeast from the Ozarks toward the Lower Mississippi
Valley tonight. Scattered TSRA should organize along the front
after 03z from KDFW/KGKY east with more isolated coverage further
west where forcing will be weaker and an elevated capping
inversion will exist. Have decided to only maintain VCTS at
KAFW/KFTW later this evening with more potential for a 1-2 hour
TEMPO group for TSRA with gusty winds across the eastern Metro.
Held only VCTS at Waco too due to a stronger cap in place.
Otherwise, all sites will see VFR conditions, though have
introduced a brief bout of MVFR AOA FL020 at Waco right after cold
FROPA due to a what could be an initially saturated and very
shallow frontal inversion. Southeast winds 5-10 knots ahead of the
cold front will become NE near 8-10 knots initially, before
increasing to 15 knots on Sunday.
05/
&&
.SHORT TERM... /Issued 313 PM CDT Sat Jun 2 2018/
/Rest of Today and Tonight/
Hot and humid conditions will continue for a few more hours, but
relief is getting closer. North winds have begun to infiltrate our
northwestern-most counties, although the cooler airmass is still
displaced up across northern Oklahoma and Kansas. The Heat
Advisory will continue through 7 PM for locales near and north of
I-20/I-30, although areas from the Metroplex and northeast towards
the Red River may remain above criteria for an hour or two beyond
this window. Instead of segmenting the current advisory to
accommodate this narrow corridor, we`ve opted to let the entire
area expire at 7 PM.
The next issue to contend with will be the potential for isolated
to scattered convection developing along the front later this
afternoon and into the evening hours. Recent ACARS soundings show
that we`re still quite capped around the Metroplex, with a plume
of +20 C air noted around 750 mb. This matches up well with recent
RAP point soundings and is corroborated by the pancake-like
cumulus field to our north. The main area of frontogenesis
associated with our front is still north of the Red River at this
hour, but the added boost from the associated ageostrophic
vertical circulations should be enough to initiate convection
along portions of the front. We`ll advertise some low PoPs north
through 7 PM, but the main window of opportunity seems to be
between about 7 - 11 PM as convection develops to our north and
moves southward into the region. The NSSL WRF has consistently
developed convection across Arkansas and eastern Oklahoma into a
surging complex this evening, and this model is typically superior
in situations where deep cold pools are expected (which is
certainly the case today with extremely large low-level theta-e
deficits and high DCAPE values). The Tech WRF Ensemble and 12z
3-km NAM are also highlighting a similar area (effectively along
and east of I-35) this evening. Given this, we`ve bumped PoPs
upwards and expanded them southward a bit to account for a
potential southward-surging complex.
Initial isolated storms through the early-evening will carry a
downburst wind threat (along with some quarter hail) with
temperatures near the century mark. Individuals out on the lakes
this evening across North Texas will want to pay close attention
to any nearby storms. Storms in these environments can send
strong-severe outflows well away from their collapsing cores with
little to no rainfall. If a more organized complex materializes
this evening, it could deliver a strong to severe wind threat
south of I-20 and east of I-35, although overall storm intensity
should be on the decrease. Isolated elevated convection may also
develop behind the surface cold front late this evening across the
I-20 corridor as the main core of frontogenesis arrives.
Otherwise, breezy north-northeast winds will arrive across North
and Central Texas tonight leading to a noticeably cooler day on
Sunday.
&&
.LONG TERM... /Issued 313 PM CDT Sat Jun 2 2018/
/Next Week/
The cool front will be moving through Central Texas Sunday morning
and will likely stall very near or just south of our southern CWA
border in the afternoon. However, some CAM models are indicating
an outflow boundary from convection to our east may slide into the
area. This may impact the progress of the front and/or this
boundary may stall across the southern portions of the region.
If either the front or a remnant outflow boundary stalls across
our southern counties tomorrow, isolated convection may occur in
the afternoon, and have kept low PoPs across Central Texas.
Downburst winds would be the main hazard with any afternoon storms
where wind shear and lapse rates are on the weaker end of the
scale but CAPE is over 2500 J/kg. Conditions north of the front
will be much more bearable with temperatures ranging from the
upper 80s to lower 90s. Locations along and north I-20 will feel
significantly less humid with dewpoints in the 40s and 50s.
The stalled frontal boundary is expected to remain across or just
south of our CWA on Sunday night as an upper level trough
approaches from the west. The trough is expected to aid in MCS
development across eastern NM and western TX. As the trough
continues moving east, the MCS should also propagate east and may
move into our area Monday morning. However, it will likely be
weakening as it arrives. The stalled frontal boundary is forecast
to be pulled north some as the upper trough approaches, resulting
in hot, humid and unstable conditions south of the front (across
Central Texas) by Monday afternoon. The combination of the upper
level trough, frontal boundary and any remnant outflow boundaries
could yield additional storms in the afternoon hours. Shear values
will be stronger and CAPE values over 2000 J/kg would yield a
severe storm potential, but uncertainty resides in IF storms will
occur and what the coverage will be so kept PoPs in the 20-30%
range for now.
The MCS and additional storms on Monday afternoon may interrupt
rain chances Monday night, but there is agreement between the
models that another MCS will affect parts of the region Monday
night into Tuesday. The operational models creep higher dewpoints
and better moisture north towards the Red River late on Monday
with the help of southerly surface winds. However, this may be
interrupted by earlier convective patterns and coverage. With some
lift still occurring with the departing upper level trough and an
increase in low level winds, the models develop the MCS to our
north or northwest and drop it southeast, mostly across the
eastern portions of the CWA late Monday night and Tuesday. If this
MCS occurs, it will be our best chance for rain next week, but
there are still questions about the mesoscale condition of the
atmosphere.
The upper level ridge will return its influence over the area
starting Wednesday and running through the end of the week. The
GFS centers the ridge over the region, but the ECMWF keeps the
ridge centered over West Texas. If the ridge is centered to our
west this would keep us in north flow aloft that may leave the
door open for north flow MCS activity. While the ECMWF indicates
potential MCS activity to our north late in the week, the latest
run does not indicate high enough chances of this activity
reaching North Texas to warrant PoPs. Another possibility if the
ridge remains to our west is isolated convection in our far
eastern counties and/or seabreeze convection in our southeastern
counties. The GFS`s location of the ridge on top of us would
likely squash any rain potential.
JLDunn
&&
.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth 75 90 68 91 73 / 40 5 0 20 30
Waco 76 94 68 93 73 / 40 20 5 20 5
Paris 71 88 64 89 67 / 50 0 0 5 50
Denton 71 89 65 90 70 / 30 5 0 20 40
McKinney 72 89 65 89 70 / 50 5 0 10 50
Dallas 77 92 70 92 74 / 50 5 0 20 30
Terrell 74 90 66 90 70 / 50 5 0 10 40
Corsicana 76 91 67 91 72 / 50 10 0 20 20
Temple 76 93 70 92 73 / 30 20 10 20 5
Mineral Wells 72 91 63 90 70 / 20 5 5 30 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 7 PM CDT this evening for TXZ091>095-100>107-
115>121-123-130>134.
&&
$$
05/26
Area Forecast Discussion
National Weather Service Green Bay WI
1030 PM CDT Sat Jun 2 2018
Updated aviation portion for 06Z TAF issuance
.SHORT TERM...Tonight and Sunday
Issued at 242 PM CDT Sat Jun 2 2018
The latest RAP analysis and satellite/radar imagery show low
pressure centered over southwest Manitoba, and an associated
occluded front extending south into southern Minnesota. Forcing
via strong shortwave over the SD/NE border to go along with mid-
level fgen and moisture transport is creating a swath of showers
and storms over eastern MN and western WI. Some of this rainfall
should move into central WI later this afternoon. Meanwhile,
clearing has finally pushed into the Rhinelander to Green Bay
corridor thanks to a dry feed of air from the NE. But as the
shortwave and associated fronts move across the region tonight,
precip chances and trends are the main forecast concerns.
Tonight...Potent shortwave over the SD/NE border will drive an
occluded/cold front across the state. Besides the surface front,
models agree that medium to strong forcing in the form of -divQ
and mid-level fgen will push a band of rain from southwest to
northeast across the region during the evening before exiting
northeast WI by the middle overnight hours. Some embedded
thunderstorms remain possible, given elevated capes of 200-300
j/kg, though thunderstorm chances will likely diminish some from
central into eastern WI. Locations that do see thunderstorms
should have the best chance of seeing the most rainfall, possibly
up to an inch. But in general, a half to three-quarters of an inch
of rain looks reasonable for most locations. Even though the
heaviest rainfall will exit late, a few spotty showers in the wrap
around part of the cyclone could linger the rain over north-
central WI through sunrise. Rather uniform low temps ranging from
the upper 40s in the north to mid 50s over the south.
Sunday...Behind the front, deep cyclonic flow will prevail through
the column. With thermal troughing and steepening low level lapse
rates with daytime heating, should have ample cloud cover with
some breaks at times in the downsloping areas. Gusty west winds
should also develop by late morning or early afternoon as temps
warm up. As for showers, though there may be a few sprinkles here
and there at times, but think most of the shower activity
(scattered) will take place over far northern WI within the
trailing comma head during the morning thru mid-afternoon. Temps
to remain cool and range from the upper 50s over Vilas County to
the mid 60s over the southern Fox Valley.
.LONG TERM...Sunday Night Through Saturday
Issued at 242 PM CDT Sat Jun 2 2018
The mean flow across the CONUS next week to generally consist of
an upper trough off the West Coast, an upper ridge over the
central CONUS and another upper trough over the eastern U.S. This
pattern would bring a west-northwest flow into WI with
temperatures at or slightly above normal and precipitation chances
tied to upper-level disturbances topping the ridge and spilling
into the Great Lakes. The main forecast challenge will be trying
to time these disturbances as models differ from day-to-day.
High pressure is forecast to build across the Upper Midwest Sunday
night and help to send drier air into the western Great Lakes.
Skies will continue to clear during the evening with west-
northwest winds diminishing to 5 to 10 mph. This would bring a
rather cool night to northeast WI with min temperatures in the
lower to middle 40s north, middle 40s to around 50 degrees south.
As the center of the high pressure moves into the MO Valley and
ridges north into WI on Monday, winds will become more westerly
with an increase in WAA through the day. Anticipate some cumulus
development, along with high clouds, however expect mostly sunny
skies to prevail. We should also see another breezy day as
soundings show mixing to at least 800mb. The WAA will bring a big
jump in temperatures with readings in the lower 70s near Lake MI,
lower to middle 70s north and middle to upper 70s south.
The next chance of precipitation in our vicinity arrives later
Monday night as a cold front to drop south out of Canada and a
shortwave moves southeast toward the eastern Great Lakes. The GFS
appears overdone with its QPF amounts, however with the frontal
boundary pushing into the forecast area, will need to at least
mention a small chance pop over most of northeast WI. More clouds
plus rain chances will prevent temperatures from falling too far.
Look for min temperatures to range from the upper 40s to around 50
degrees north, middle to upper 50s south. Precipitation chances
may linger into Tuesday morning across far southern sections of
the forecast area as the cold front to still be in the process of
exiting the area. Otherwise, a weak area of high pressure is
forecast to move into northern sections of the Great Lakes Tuesday
afternoon and bring sunshine back to all of northeast WI. Cooler
air to filter into WI behind the cold front, thus max temperatures
are expected to be in the upper 60s near Lake MI, mainly lower to
middle 70s elsewhere (although a few upper 70s are possible over
central WI).
After a quiet Tuesday night with high pressure in control,
attention turns to the northwest where a cold front and mid-level
shortwave trough to be co-located on Wednesday. Models continue to
differ on the timing of these features with the faster GFS/GEM
quickly sending the front and trough into WI by Wednesday
afternoon, while the slower ECMWF still only has these features in
the Upper MS Valley with dry conditions for northeast WI. Since
either solution is plausible at this point, have mentioned a small
chance pop for Wednesday across the forecast area. Temperatures
aloft do not change much going into Wednesday, thus max
temperatures should be fairly similar to Tuesday.
The timing issue to persist Wednesday night into Thursday morning
as the GFS/GEM end the precipitation chance (Wednesday evening)
and have dry conditions for Thursday. The slower ECMWF sends the
cold front/shortwave trough through WI Wednesday night with
showers/possible thunderstorms before ending as light showers
Thursday morning. Unfortunately, will need to stick with low-end
precipitation chances through Thursday morning until the models
can get into better agreement. Under the assumption that all
precipitation will be gone by Thursday afternoon, this would allow
temperatures to warm with readings in the lower 70s near Lake MI,
upper 70s to lower 80s elsewhere.
Another weak area of high pressure moves into the Great Lakes
Thursday night, thereby bringing mostly clear skies and light
winds to the region. This high pressure is forecast to hang on
through Friday with max temperatures similar to Thursday. The next
shortwave trough to top the ridge is progged to approach WI next
Saturday. Once again, models are struggling on when or if any
precipitation would fall over the area. For now, have gone
optimistic and prefer to keep the forecast dry for both Friday
night and Saturday. Temperatures should continue to run a few
degrees above normal.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1028 PM CDT Sat Jun 2 2018
The last main band of showers with the strong shortwave crossing
the region will shift across the area overnight. Some fog
development is likely as winds slacken near the front. Low
ceilings (IFR/LIFR) are likely as well. Ceilings should lift from
west to east late tonight and tomorrow morning in the wake of the
front. Gusty west winds are expected during the day. &&
.MARINE...
Issued at 242 PM CDT Sat Jun 2 2018
Gusty west winds will develop from late morning through
the afternoon on Sunday. Wind gusts should just reach small craft
advisory criteria (25 kts) along the nearshore waters adjacent to
Manitowoc county but fall shy elsewhere. Small craft should still
exercise caution further north along Lake Michigan and the Bay of
Green Bay as gusts to 20-25 kts will be possible.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......AK
AVIATION.......Skowronski
MARINE.........MPC
Area Forecast Discussion
National Weather Service Huntsville AL
935 PM CDT Sat Jun 2 2018
.NEAR TERM...(Rest of tonight)
Issued at 935 PM CDT Sat Jun 2 2018
Evening satellite imagery shows very little to speak of over the
Tennessee Valley, aside from debris cirrus left over from upstream
convection. There are a few showers that have managed to develop from
cumulus over middle Tennessee, but they are few and far between
thanks to significant mid-level dry air. Meanwhile, convection over
Arkansas & Missouri is the main concern for the next 8-12 hours.
A rogue shower or storm can`t be ruled out mainly over southern
Tennessee this evening, but for the most part, the area should remain
dry until after 06Z. High-res models are consistent in taking the
AR/MO convection mostly to the south across Memphis and Mississippi,
which is in line with steering flow and low-level Theta-E patterns.
Previous HRRR and HRRR-Dev runs had suggested the potential for some
outflow-induced activity edging into NW Alabama after 07-08Z, which
seems to be the most reasonable solution. Interestingly, more recent
HRRR runs are more aggressive with redevelopment from the middle TN
activity, which gets pushed into NE Alabama.
For now the forecast will reflect the previous HRRR/HRRR-Dev solution
noted above, but trends over middle TN will need to be monitored. Low
temperatures based on blends/persistence are in good shape.
.SHORT TERM...(Sunday through Monday)
Issued at 251 PM CDT Sat Jun 2 2018
The aforementioned cold front will traverse the area through the day
Sunday, with showers and storms expected off/on for much of the
morning and through early tomorrow afternoon. With MUCAPE values
approaching 2500-3000 J/kg and PWats upwards of 1.8", gusty winds of
40-50mph will be possible in any stronger storms that develop, though
a severe storm or two can`t be ruled out. Heavy rainfall will
accompany the showers/storms as well. This has been highlighted in
the HWO again this afternoon.
Thankfully, for those who aren`t quite ready for the Summer-like
weather we`ve been having lately, there`s a break on the horizon! In
the wake of the fropa tomorrow afternoon/evening, sfc high pressure
builds into the area, bringing much drier air. Hello dewpoints in the
middle 50s! This drier and more pleasant trend continues for Monday,
with few clouds expected. High temps Monday will top out in the lower
80s as well, making for a nice (and finally dry) start to the work
week.
.LONG TERM...(Monday night through Friday)
Issued at 251 PM CDT Sat Jun 2 2018
Tuesday and Wednesday will honestly be a rinse-and-repeat forecast
from Monday. Morning lows will start out in the 55-60F range and top
out in the lower 80s. RHs will be noticeably drier during this time,
making for a nice break from the swampy/humid conditions as of late.
As the sfc high shifts E through the week, southerly flow will return
to the CWFA Thursday through the weekend. The big conundrum in the
extended is just how far E the upper ridge building to our W will
become established. If you believe the GFS, it`s further W, and we`ll
see additional rounds of convection as disturbances ride up/over
this feature. With our area in NW flow during this time, cue the
march of MCSs and showers/storms daily (or at times, twice daily).
The ECMWF, however, has a stronger ridge to our W and has it more
established further E, putting the Carolinas in NW flow and the
recipient of the march of the MCSs. Either way, the nice and
enjoyable weather to start the week will sadly come to an end, and a
return to a more seasonable pattern of NW flow and MCSs developing to
our N and decaying somewhere on their journey SEwrd will be the
norm. Haven`t made too many changes to the PoPs during this time, but
more details will have to be hashed out in the longer-range models
to paint a more clear picture of late next week and into next
weekend.
Temps through the extended will increase, topping out in the upper
80s and lower 90s by Thu/Fri and into next weekend. Morning lows will
moderate as well, increasing to near 70F by next Fri/Sat.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 538 PM CDT Sat Jun 2 2018
VFR flight weather conditions are expected this evening. Patchy fog
is possible late tonight, especially near the TN River including
KMSL. Have included a tempo period from 09-12Z with 2SM BR. Isolated
thunderstorms cannot be ruled out late tonight, but the best chance
will occur along or just ahead of a cold frontal passage from
13-18Z Sunday.
&&
.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&
$$
NEAR TERM...BCC
SHORT TERM...12
LONG TERM...12
AVIATION...17
For more information please visit our website
at weather.gov/huntsville.
Area Forecast Discussion
National Weather Service Memphis TN
943 PM CDT Sat Jun 2 2018
.UPDATE...
Have updated to extend the Severe Thunderstorm Watch through
midnight for most of the E Arkansas counties. The storms currently
in NE Arkansas continue to pose a large hail and damaging wind
threat as they move to the SE. Still anticipated to begin
weakening over the next couple of hours.
ZDM
&&
.PREV DISCUSSION... /issued 755 PM CDT Sat Jun 2 2018/
UPDATE...
Currently, showers and thunderstorms are ongoing to the NW of the
CWA in association with a surface cold front. The front currently
extends roughly from NW Arkansas northeastward through S
Illinois. These storms are currently discrete out ahead of the
front, but are expected to congeal into a line as they progress
further SE.
Latest mesoanalysis places a tight instability gradient roughly
along the MS River, with much more stable air present over W TN,
with much lower 850 hPa RH values there indicating the presence of
dry air contributing to a more stable atmosphere. This coincides
well with the latest runs of the HRRR, which bring a line of
storms SSE through the CWA, a cold pool propagating along the
instability gradient. The latest HRRR run brings the storms
through the Memphis metro between 11 PM and midnight. The storms
will be capable of producing large hail, with damaging winds a
secondary threat. Latest thinking is NE Arkansas and the Missouri
Bootheel stand the best odds of severe storms, as the storms will
likely wane in intensity as they move to the SE.
Have updated POPs to account for the latest timing. Confidence in timing
and strength of the line of storms remains limited at this time.
The Severe Thunderstorm Watch remains in effect for E Arkansas and
the Missouri Bootheel through 10 PM.
ZDM
PREV DISCUSSION... /issued 244 PM CDT Sat Jun 2 2018/
DISCUSSION...Surface analysis this afternoon places a cold front
from Northwest Missouri back through Eastern Kansas and West
Texas. A hot and humid airmass is in place across the Lower
Mississippi Valley this afternoon with temperatures as of 2 PM CDT
in the upper 80s to lower 90s with surface dewpoints in the 70s.
Severe thunderstorm potential for the remainder of the afternoon
into the evening will be the primary focus in this afternoon`s
forecast issuance.
Regional WSR-88D radar trends have indicated the development of a
scattered line of showers and thunderstorms just ahead of a cold
front. A Mesoscale Convective Vortex (MCV) over Missouri is
providing additional lift over the region. The lift produced by
this feature and the cold front combined with a very warm, moist,
and unstable airmass will support the development of showers and
thunderstorms across the Mid-South into tonight.
Short term models including Convective Allowing Models (CAMs)
indicate showers and thunderstorms will continue to develop and
push across Arkansas for the remainder of the afternoon and
affecting portions of East/Northeast Arkansas and the Missouri
Bootheel until early evening. This convective activity is
anticipated to reach the Mississippi River between early to
evening, and across the remainder of the Mid-South late evening
into the overnight hours. Some uncertainty remains between the
models on timing and coverage and will be closely monitored as the
event unfolds.
Surface based CAPE values in excess of 3000 J/kg, steep 700-500
mb layer mid- level lapse rates around 7 C/km, and 0-6 km Bulk
Shear values around 40 kts support the potential of some strong to
severe thunderstorms across the region late this afternoon into
tonight. Damaging winds is expected to be the predominant threat
along with a secondary threat of large hail. Localized heavy
rainfall may also be possible with these thunderstorms.
Slightly cooler and drier air will filter into the Lower
Mississippi Valley into early next week. Long term models indicate
an upper level ridge will attempt to build across the region into
much of next week. However, much of the region will remain on the
eastern periphery of the upper level ridge axis placing the Mid-
South within northwest flow aloft. Confidence in shower and
thunderstorm chances next week remains low as models differ on
timing of individual mid-level shortwave troughs and the strength
of the ridge. Consequently, have leaned toward isolated rain
chances until models come into better agreement.
CJC
&&
.AVIATION...
00Z TAFs
Warm midlevel temps (FL050-FL150) effectively capped TSRA development
over the Midsouth earlier this afternoon. Cooler temps aloft will
arrive later this evening (04z-06z at MEM) as a midlevel
disturbance weakens upper level ridging.
Latest few HRRR runs have been consistent with potential TSRA
timing. Strength and coverage will dependent on how well or if
TSRA can organize a cold pool over southern MO and forward
propagate south/southeast quickly enough to overcome otherwise
weak southerly inflow and relatively dry air above FL040.
In summary, forecast confidence for TSRA in the MEM TRACON is
limited, but enough potential exists to maintain the status quo,
with minor adjustments to timing.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
Area Forecast Discussion
National Weather Service Marquette MI
718 PM EDT Sat Jun 2 2018
.SHORT TERM...(This evening through Sunday)
Issued at 415 PM EDT SAT JUN 2 2018
Water vapor imagery and RAP analysis show a vigorous trof taking on
an increasingly negative tilt over the Plains. Healthy upper
diffluence, typical of a negative tilt wave, and deep layer forcing
has been supporting bands of shra and embedded thunder across
western WI and MN today. Leading edge of pcpn is nearing KIWD now.
Otherwise, it`s been a mostly sunny aftn across much of the fcst
area as clouds are confined closely to the approaching area of shra.
Negatively tilted mid-level trof will continue to progress eastward
and will be centered over the Upper Great Lakes on Sun aftn.
Combination of vigorous upper diffluence and deep layer forcing
under 120m/12hr height falls at 500mb will support shra spreading
eastward across the fcst area tonight into Sun morning along ahead
of 850mb trof. Mid-level trof begins to lose some of its sharpness
as it swings across the area, so there may be a tendency for pcpn
amounts to decrease overall with eastward extent. Expect all
locations to receive some rainfall, broadly on the order of 0.25 to
0.6 inches. While there has been thunder occurring at the leading
edge of the shra band to the w on the front gradient of mucape of
500j/kg, instability is fcst to weaken/slide se this evening. So,
not expecting much more than maybe a few rumbles of thunder this
evening from vcnty of KIWD toward KIMT. After the main band of shra
exits the e in the morning, mid-level trof over the area during Sun
will probably support isold to sct -shra. Expect quite a bit of
cloud cover, similar to what is being observed this aftn on the
backside of the trof from ne ND into Saskatchewan. Thus, it will be
a cool day with highs ranging from around 50F along Lake Superior
over the nw to mid 60s s central. Lakeside locations exposed to w
winds off Lake Superior may only be in the 40s during the day.
.LONG TERM...(Sunday night through Saturday)
Issued at 331 PM EDT SAT JUN 2 2018
No significantly impactful weather anticipated in the long term.
Some light rain will exist east on Sun night, leaving breezy
conditions and seasonal temps for Mon. There is potential for some
showers and perhaps some thunder late Mon evening into Mon night as
a shortwave possibly passes nearby, but there is plenty of
uncertainty with that. At this time, have 15-30% PoPs covering this.
Next chance of precip following that is in the Wed to Thu time frame
when models show a stronger shortwave somewhere in the region. Even
greater uncertainty exists with this precip.
Overall did not make any changes to the blended initialization given
that it handled things well.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 710 PM EDT SAT JUN 2 2018
As a frontal boundary from the Plains sweeps eastward, a band of
shra will move across the area tonight, affecting KIWD/KCMX/KSAW
and lowering cigs to MVFR then IFR. Vis may be reduced to MVFR at
times. As the shra diminish in intensity/coverage later
tonight/Sun morning from west to east, not out of the question
that cigs could dip to LIFR for a time. Otherwise, expect MVFR
clouds to persist even into Sun afternoon as west winds become
gusty to 20 knots behind the front at KIWD and KCMX.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 415 PM EDT SAT JUN 2 2018
Ahead of an approaching front, e to ne winds of 15-25kt with a few
gusts to 30kt, strongest over the w half of Lake Superior, will
continue into the evening, before diminishing from w to e. In the
wake of the front passing across the lake late tonight thru Sun
aftn, w winds will be on the order of 10-20kt. W to nw winds will
then increase Sun night/Mon, especially over the e half of the lake
where winds of 20-30kt are expected. Winds will then be under 20kt
Tue thru Thu.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...Rolfson
LONG TERM...Titus
AVIATION...Voss
MARINE...Rolfson
Area Forecast Discussion
National Weather Service Nashville TN
904 PM CDT Sat Jun 2 2018
.UPDATE...
FOR EVENING DISCUSSION.
&&
.DISCUSSION...
A few showers have developed in the last hour along a residual
outflow boundary situated northwest to southeast from Hopkinsville
toward Murfreesboro. The 00z OHX sounding showed ample
instability with a strong 700 mb cap. Any showers in the next
couple of hours should be isolated and short-lived due to the
strength of the cap. Eyes are still to the west as we watch the
cold front approach the area overnight and into the morning.
Currently the front is sitting near Fort Smith, AR northeastward
toward St Louis. The 18z GFS, 00z NAM, and numerous runs of the
HRRR keeps the area mostly dry through the overnight hours with
most of the activity staying in West Tennessee. I took that idea
and ran with it by cutting back PoPs after 06z and only left 30
PoPs in the west. The HRRR does develop some showers along and
ahead of the front late in the morning on Sunday mainly over the
Cumberland Plateau. Besides PoPs and hourly temperature and dew
point adjustments, no other changes were made to the forecast.
&&
.AVIATION...
00Z TAF DISCUSSION.
VFR conditions are expected at airports through the TAF period,
although patchy fog will bring MVFR visibility to CSV for a few
hours around sunrise, and a brief hour or two of MVFR cigs are
possible Sunday morning as a cold front moves across the area.
Confidence has decreased that any SHRA or TSRA will affect
terminals overnight and precip mention was removed from TAFs.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION......Reagan
AVIATION........Shamburger
Area Forecast Discussion
National Weather Service Tucson AZ
836 PM MST Sat Jun 2 2018
.SYNOPSIS...The hottest temperatures of the year so far are
expected on Sunday. The heat continues through next week with a
slight chance of thunderstorms in the mountains east of Tucson
Thursday and continuing into next weekend.
&&
.DISCUSSION...Dry with above average heat today. Our first 104 of
the year at TUS. High pressure across northern Mexico will mean
more of the same for our area tomorrow, with 850-700mb thicknesses
supporting another 2 or 3 degrees of heating. Things are getting
more interesting east of our area. Note the winds backing more
southeasterly below 600mb on the KEPZ sounding. Deeper moisture
from west Texas and Chihuahua is in the process of pushing into
NM with a dry line sharpening in the process. Most of the fun will
stay in New Mexico, but the HRRR shows a low level push of 50
degree dewpoints into Greenlee, eastern Graham and northeast
Cochise county later tomorrow morning. Expect CU fields in eastern
areas tomorrow with a few buildups possible near mountains closer
to the NM border. A minor evening adjustment to the forecast to
reflect these trends a little more.
Otherwise, please see the previous discussion below for additional
details about the coming week.
&&
.AVIATION...Valid through 04/06Z.
Clear west to FEW-SCT clouds above 12k ft AGL near the New Mexico
border. Surface winds variable, less than 10 kts overnight. Gusty
W-SW winds return Sunday afternoon after 03/19Z. Aviation
discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Dry conditions through Wednesday. However, there will
be a slight chance of mainly dry thunderstorms across the White
Mountains Sunday. Through this period the Haines index will reach 6
at times, mainly eastern zones. Then increasing moisture will bring
a slight chance of thunderstorms to the mountains of Fire Zones 152
and 153 Thursday into next weekend. Very little precipitation is
expected if storms occur with the biggest threat being dry lightning
strikes and strong outflow winds. 20-foot winds will be slightly
elevated this afternoon and somewhat less on Sunday. Elevated winds
will return Monday and Tuesday afternoons.
&&
.PREV DISCUSSION...A hot Saturday afternoon with some breezes
under dry southwesterly flow aloft on the eastern periphery of a
weak upper low now across the lower Colorado River Valley and
moving towards the north-northeast. The upper low will continue to
move into the Four Corners region on Sunday. Some short lived
moisture will seep into far eastern areas late tonight into Sunday
with some build-ups possible across the White Mountains before
drier air sweeps in from the west by Sunday afternoon. Near record
to record highs are expected across the area Sunday with highs
about 7 to 10 degrees above normal.
Heading into the work week, the subtropical high will continue to
build and become rather expansive across northern Mexico into New
Mexico and the western half of Texas. This will place southeast
Arizona under a more southerly flow aloft. While moisture to our
south is currently lacking, the prolonged southerly flow will help
draw moisture into portions of southeast Arizona for the latter half
of the week. In the meantime, continued dry with above normal
temperatures through Wednesday. Enough mid and upper level moisture
will move in starting Thursday to increase the chances of mainly dry
thunderstorms across the higher terrain to the east of Tucson. The
threat of mainly dry thunderstorms will continue Friday into next
weekend as well, though confidence is lower then as there are some
differences amongst the models as the GFS/GEFS keeps the subtropical
high placement a bit more to our east compared to the ECMWF. Should
the more eastern solution of the GFS/GEFS hold, we`ll have a better
chance of thunderstorms compared to the ECMWF which is the
drier/hotter solution.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
Meyer/Lader
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