Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/03/17
Area Forecast Discussion
National Weather Service Albany NY
1032 PM EDT Fri Jun 2 2017
.SYNOPSIS...
An upper level low will remain over the region through Saturday,
allowing for continued below normal temperatures. Although it should
remain dry most of the time, a brief passing shower cannot be ruled
out. A widespread soaking rainfall will return to eastern New York
and western New England Sunday afternoon into Monday, as a warm
front and a low pressure system moves towards the area from the
west.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
As of 1032 PM EDT, Any isolated showers earlier this evening
have dissipated with loss of daytime heating. The air mass in
place is very dry for early June with surface dewpoints the
upper 30s to lower 40s. Will mention dry conditions through much
of the overnight.
One last organized upper level disturbance rotates through our
region late tonight into Saturday morning. There is little
moisture to work with, so expecting only isolated showers
across far southern areas early Saturday morning. 00Z hi-res
guidance such as the HRRR and 3-km NAM indicating the bulk of
more widespread shower activity should occur south of our
forecast area, where more vigorous forcing will exist.
Temperatures tonight will be quite cool again, as some northern
areas could drop to the upper 30s to around 40 with most areas
in the 40s.
On Saturday the cyclonic upper flow and cool boundary layer
temperatures will result in continued below normal temperatures
and a few more showers in higher terrain of the southern
Adirondacks and southern Green mountains cannot be ruled out.
Highs Saturday a degree or two cooler than today, in the 60s to
lower 70s but upper 50s northern areas.
Strengthening warm advection and isentropic lift along a
tightening of the boundary layer thermal gradient will support
increasing clouds Saturday night. There may be a period of
clearing Saturday evening allowing temperatures to drop rapidly
before clouds increase through Saturday night. Temperatures
could fall to similar levels as tonight, meaning around 40
northern areas with most other areas in the 40s.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
Sunday...The 2nd half of the weekend will be cool and wet as
clouds continue to thicken and lower in the morning from the
west to southwest ahead of an advancing warm front. The
isentropic lift increases on the 295/300K surfaces with a
strengthening south to southwest low-level jet of 30-40 kts on
the GFS/NAM/ECMWF. We gradually brought some light rain into
locations west of the Hudson Valley in the late morning, and
then increased the pops to likely and low categorical values by
the afternoon. The highest pops are over the western
Adirondacks, western Mohawk Valley and eastern Catskills. The
mid level flow is initially fairly zonal ahead of the upper
trough digging into the Upper Midwest and west-central Great
Lakes. Temps will still be below normal with the increasing
cloud cover and rain moving in. High will only be in the mid and
upper 60s in the valleys, and upper 50s to lower 60s over the
higher terrain.
Sunday Night...The warm front gradually lifts north and east
across most of the region /possibly hangs up over the I-90
corridor/ with the sfc cyclone moving east to northeast over
the eastern Great Lakes corridor. PWATs values remain slightly
above normal and good moisture advection continues for periods
of rain and a slight chc of thunderstorms as both the NAM/GFS
have a corridor of 0 to -2C Showalter stability indices
/elevated instability/ move into the region. The rainfall may
become moderate to heavy in intensity at times with the
embedded convective elements. A cool and damp evening is
expected with lows in the mid 40s to mid 50s. There is some
evidence of a dry slot moving in from the south and west towards
daybreak with a closed/cut-off H500 low moving over the central
and eastern Great Lakes Region embedded in a positively tilted
longwave trough. For now we have kept the pops as likely until
daybreak.
Monday...Low pressure remains near the eastern Great Lakes
during the day as it captured by the H500 circulation, as the
triple point to the system may set up over central and eastern
NY. Strong differential cyclonic vorticity advection with short-
wave energy pivoting around the low will continue the rain
especially during the afternoon. There is a slight chance of
thunderstorms with some MUCAPE evident in the guidance, though
the GFS values look much too high. Any brief clearing should
fill in quickly. Intermittent periods of rain with embedded
thunderstorms are possible again. A blend of the guidance yields
highs in the mid/upper 50s to lower 60s north of the Mohawk
Valley/Capital Region/southern Berkshires with mid 60s to around
70F from these locations south into the mid-Hudson Valley with a
few cooler readings over the mountains. Total rainfall Sunday to
Monday is expected to be in the 1 to 1.5 inch range.
Monday Night into Tuesday...The mid and upper level low cuts off
over NY and nrn PA. We have leaned closer the ECMWF with the
placement of the closed/cut-off low right over upstate NY. The
cyclonic vorticity advection will keep the threat of showers
going Monday night. Pops were kept in the likely range. Temps
will be on the cool side once again in the mid 40s to lower 50s.
Multiple impulses/sfc trough will be rotating around the cut-
off for scattered to numerous showers once again on Tuesday. The
placement and location of the cut-off will make a difference in
how heavy any rainfall will be with it. Local CSTAR research
has documented precipitation patterns/sensible with warm season
cut-offs. If the cut-off is further south over s-central PA
there could be some bands of heavy showers and thunderstorms as
the GFS is indicating. Again, our forecast is closer to the 12Z
ECMWF placement with an additional quarter to half inch or so
of rainfall MON night into TUE. With the core of the coldest air
potentially over the region /-20C or so at H500/. Max temps may
only be in the 50s to lower 60s across the region which is 15
to 20 degrees below normal.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
This will be mostly a wet period...with a possible break between
systems Wednesday night. An inverted trof sticks around behind a
cold front for the first 24 hours of the period, providing showery
activity. Weak high pressure builds in Wednesday night, to be
followed by a cold front and showers especially from Thursday
afternoon on. A repeat scenario of inverted trof behind cold front
will also keep showers in the forecast at the end of the work week.
Wednesday will be unseasonably cool with high temperatures ranging
from the mid 50s to mid 60s. Thursday will be more seasonable...but
still below normal...with highs ranging from around 60 degrees in
the high peaks...to the lower and mid 70s down the Hudson Valley.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions expected to prevail at the KALB/KPOU/KGFL/KPSF
TAF sites through the end of the TAF period ending at 00Z
Sunday. SCT-BKN mid level clouds will persist into this evening
before dissipating. Then, stratocumulus clouds are expected to
increase again Saturday morning associated with another
disturbance moving through the region. Cigs expected to remain
in VFR range, around 5-6 kft. Skies should tend to become more
scattered later Saturday afternoon as the disturbance departs
and high pressure starts to build in from the west.
Wind will be northwest around 10-15 kt early this evening,
becoming west-northwest around 5-10 kt by later in the evening.
Winds will again shift to the northwest and increase to around
10-15 kt with gusts around 20-25 kt Saturday afternoon.
Outlook...
Saturday Night: No Operational Impact. NO SIG WX.
Sunday: High Operational Impact. Likely RA.
Sunday Night: High Operational Impact. Definite RA...TSRA.
Monday: High Operational Impact. Likely RA...TSRA.
Monday Night: High Operational Impact. Likely SHRA.
Tuesday: Moderate Operational Impact. Likely SHRA.
Tuesday Night: Moderate Operational Impact. Chance of SHRA.
Wednesday: Moderate Operational Impact. Chance of SHRA.
&&
.FIRE WEATHER...
An upper level low will remain over the region for tonight
through Saturday, allowing for continued below normal
temperatures. Although it should remain dry most of the time
isolated showers cannot be ruled out into Saturday. A
widespread soaking rainfall will return to the region Sunday
afternoon into Monday as a warm front and low pressure system
impacts the area. Wet, cool and damp weather is expected into
the mid-week.
The RH values rise to 75 to 100 percent tonight and lower to 35
to 60 percent on Saturday. Northwest winds will diminish to 10
mph or less tonight and increase to 10 to 20 mph Saturday with
some gusts around 25 mph. The RH values will increase to 80 to
100 percent Saturday night with the winds becoming light and
variable at less than 5 mph.
&&
.HYDROLOGY...
An upper level low will allow for some isolated to scattered
rain showers late this afternoon into early this evening.
Rainfall amounts will be very light and will have little to no
impact on area rivers and streams.
After a mainly dry day Saturday into Saturday night, a soaking
rainfall will return for Sunday afternoon into Monday. Around an
inch to one and a half inches of rainfall is expected with this
next system. Although some rivers will see within bank rises
during this time frame, no flooding is currently expected. The
latest MMEFS guidance has a few points get to the action/alert
stage but again no flooding is anticipated.
Additional rain/rain showers will continue into the middle of
next week, as a cutoff low pressure system remains near the
region. Additional rainfall is expected Monday night into
Tuesday in the quarter to half inch range. Additional lighter
amounts are possible Tuesday night into Wednesday. Flows will
remain high and will need to be monitored due to the wet pattern
over the Hydro Service Area the past several weeks.
For details on specific area rivers and lakes, including
observed and forecast river stages and lake elevations, please
visit the Advanced Hydrologic Prediction Service /AHPS/ graphs
on our website.
&&
.EQUIPMENT...
The ASOS at Glens Falls, NY continues to experience outages
with hourly METARS occasionally or continuously missing. This
will persist until communications are fully restored.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...11/Wasula
NEAR TERM...11/JPV
SHORT TERM...Wasula
LONG TERM...ELH
AVIATION...JPV
FIRE WEATHER...NAS/Wasula
HYDROLOGY...NAS/Wasula
EQUIPMENT...
Area Forecast Discussion
National Weather Service Gaylord MI
1147 PM EDT Fri Jun 2 2017
.UPDATE...
Issued at 1030 PM EDT Fri Jun 2 2017
Band of deeper mid level moisture and attendant sprinkles
continues to pinwheel southeast across northern Lake Huron. Simple
extrapolation keeps any rain threat to our east overnight.
Otherwise, a quiet night with just a few passing high and mid
level clouds. Nocturnal temperature response well underway, and
dry air and plenty of clear skies should allow temperatures to
drop several more degrees by sunrise. Still a mild night overall,
with readings by morning only dropping into the upper 40s to
middle 50s.
&&
.NEAR TERM...(Tonight through Saturday)
Issued at 301 PM EDT Fri Jun 2 2017
...Increasing chances of showers and storms Saturday...
High Impact Weather Potential...Chance of thunderstorms Saturday
afternoon.
Pattern Synopsis/Forecast...Strong surface high remains over the
Great Lakes region southward thru the Ohio Valley this afternoon...
with the upper level ridge axis pushing eastward into the
Mississippi Valley. Scattered mid cloud continues to stream
southward out of Western Ontario and into Michigan thanks to limited
mid level moisture spilling over top of the upper level ridge axis.
Temps are...as usual...cooler near the lakes...but inland areas have
warmed nicely into the 70s for much of inland Northern Lower
Michigan and into the mid to upper 60s across Eastern Upper
Michigan.
Little will changes as we head into tonight. Scattered mid cloud
will continue to spill into Michigan...resulting in partly to mostly
clear skies. Low temps will fall mainly into the upper 40s and lower
50s. Pattern begins to shift on Saturday as a warm front lifts NE
into the Western Great Lakes region. NAM is more agressive (both in
timing and amount) in bringing precip into our SW CWA during the
morning...while the the RAP holds light precip further west over
Wisconsin thru morning. Think the RAP has the right idea and have
thus limited POPs to after 18Z...slowly spreading increasing pops
from SW to NE into our CWA thru the afternoon. Still expect better
chances of precip will likely hold off until Saturday night when
better moisture...lift and instability arrive just ahead of the
surface low. Any marginal chance of severe storms will likely happen
during this time as well.
Expect another warm day across the Northwoods for Saturday as CAA
ahead of the low continues. High temps will range from the upper 60s
in Eastern Upper Michigan to the upper 70s across much of our
southern CWA.
&&
.SHORT TERM...(Saturday night through Monday)
Issued at 301 PM EDT Fri Jun 2 2017
...More Shower/Storm Chances...
High Impact Weather Potential...Possible strong to severe storms
Saturday night.
Slow height falls from an incoming trough well to our northwest will
likely lead to showers and scattered thunderstorms Saturday night as
moisture increases (precipitable waters in the 1.25 to 1.5 inch
range). Modest shear (0-6 km bulk shear 30 to 40 kts) could lead to
a few strong to severe storms with damaging wind gusts the primary
threat; large hail and heavy downpours are also possible. In the
meantime, an upper level trough currently evident on water vapor
loop over northern Saskatchewan tracks southeast into southeast
Ontario by Monday. This system will bring periodic chances for
showers and thunderstorms, mainly instability driven during the
afternoon. Sunday afternoon appears to be more active than Monday
when the trough is exiting the area. Temperatures will be near
normal during this time (which isn`t too bad considering).
.LONG TERM...(Monday night through Friday)
Issued at 301 PM EDT Fri Jun 2 2017
High pressure building into the region will bring quiet weather and
temperatures near to slightly above normal through most of the
extended period. A shortwave late in the week could bring a brief
period of showers.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1144 PM EDT Fri Jun 2 2017
Mid and high clouds expected to continue across the taf locations
through this morning. Approaching system brings gradually lower
clouds into this evening, although dearth of deeper low level
moisture should keep conditions primarily VFR. Late day showers
are expected, with some potential of brief periods of MVFR
conditions during the evening in any heavier showers. May even
hear a rumble of thunder or two, although confidence is much too
low to include a mention of such in this taf cycle. Light winds
expected through this taf period.
&&
.MARINE...
Issued at 301 PM EDT Fri Jun 2 2017
Winds and waves will remain below SCA criteria across our nearshore
areas tonight thru Saturday night. Chances of showers and
thunderstorms will begin to increase by Saturday afternoon ahead of
an approaching warm front. Better chances of showers and storms will
develop Saturday night.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...MSB
NEAR TERM...MLR
SHORT TERM...AJS
LONG TERM...ALM
AVIATION...MSB
MARINE...MLR
Area Forecast Discussion
National Weather Service Binghamton NY
753 PM EDT Fri Jun 2 2017
.SYNOPSIS...
Partly to mostly cloudy skies and cool temperatures will prevail
over the region tonight. Some showers will affect parts of
northeast PA and the central southern tier of NY late tonight.
Saturday will become mostly sunny as high pressure moves in.
The next storm system will move into the region Sunday and bring
more chilly weather with rain and showers into Tuesday.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
7 pm update...
Skies are mostly clear with temperatures slowly falling. Cloudy
skies in Oneida County will be slow to clear but should. Showers
staying well to the northeast of there in the Dacks. Late
tonight left forecast alone with increasing clouds and some
showers for the southwest quarter.
previous discussion...
Water vapor channels on the GOES 16 continue to clearly show an
upper level wave moving across NY and PA at this time with a
cold pool aloft. This cold pool combined with some boundary
layer moisture, strong late spring insolation and upsloping
into central NY has led to widespread clouds across much of
central NY and northern PA. There were also a few isolated
showers developing in our higher terrain of north central NY to
the northern Catskills. We expect these diurnally driven clouds
and isolated showers to peak late afternoon and then wane after
sunset.
Then for later tonight, high resolution models including NAM 3km
nest and the HRRR and synoptic models bring a band of showers
southeast in association with another well defined upper level
wave presently moving south of James Bay. This feature is
projected to work through NY and PA late tonight and bring a
band of rain showers across western NY, and northern PA. So we
have expanded POPs for showers in these areas and increased
cloud cover for later tonight.
Once this wave passes, our area will see subsidence under upper
level confluent flow and clearing for Saturday before the next
wave approaches for Saturday Night.
This next upper level feature will reach into Upper Midwest
by 12z Sunday with a surge of low-level warm and moisture
advection into the eastern Lakes. This will lead to lift and a
batch of showers arriving into western NY late Saturday night.
Synoptic scale models bring a little precipitation into the
western Finger Lakes region between 9 and 12z Sunday. We will
have chance POPs in these areas and increasing cloud cover rest
of forecast area.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
Vigorous short wave dropping through the upper low taps available
gulf moisture and spreads rain into the region Sunday. Deep
moisture and favorable upper jet will keep moderate rain with
embedded thunder through Monday. Triple point passes south of
the area Monday afternoon and somewhat drier air arrives late in
the day. However, instability associated with the upper low
will continue the rain and the possibility of thunder.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
Thankfully the upper low is slow but progressive. Stacked system
off the Maine coast by 12Z Wednesday, but northerly flow and
cool upper air will keep showers in the forecast through
Wednesday afternoon, especially in the eastern zones. High
pressure builds in late Wednesday and holds into Thursday
bringing drier conditions ahead of a open wave forecast to drop
through on Friday. In the northwest flow, coo, air will keep
temperatures below normal through Wednesday, with a return to
near normal temperatures on Thursday.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
730 pm update...
VFR conditions will prevail through the terminal forecast
period up to 00Z Sunday. Only RME has clouds this evening and 5k
ft. Late tonight broken to overcast low to mid deck but still
VFR. Light showers possible 08 to 12z at ELM and probably AVP
but still VFR. Saturday morning clearing to become clear during
the afternoon.
Gusty west to northwest winds subsiding quickly to be light and
variable after 03z. At 12z winds increase to 6 to 10 kts again
from the west and northwest. By 16z winds increase to 10 to 15
kts with gusts to 20 to 25 kts. Subsiding after 22z.
Outlook...
Saturday night...VFR.
Sunday - Tuesday...MVFR and IFR in showers.
Wednesday- VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.
&&
$$
SYNOPSIS...DJN/TAC
NEAR TERM...DJN/TAC
SHORT TERM...DGM
LONG TERM...DGM
AVIATION...TAC
Area Forecast Discussion
National Weather Service Charleston SC
942 PM EDT Fri Jun 2 2017
.SYNOPSIS...
A weak pressure pattern will prevail across the forecast area under
the western periphery of subtropical high pressure through the
weekend. A cold front is then expected to approach the area starting
on Monday and eventually push to the south by the middle of the
week. Drier and cooler high pressure will return thereafter.
&&
.NEAR TERM /THROUGH SATURDAY/...
No significant changes with the late evening update. We did
however show a little less cloudiness north and a little more
clouds south and made minor tweaks to temps and dew points.
Forecast still appears on track. Despite the SREF showing 25-30%
chances of fog late tonight, the HRRR has very little coverage
of fog and FSI`s are only as low as in mid 20s. Thus we continue
to hold off on any mention of fog at this time.
A diffuse cold front, actually more of a wind shift and dew
point front, is located not far to the N-NW of the local area,
and will dissipate over or near our northern zones late tonight.
Meanwhile upstairs, a zonal W-NW flow will dominate,
maintaining a fetch of drier air, most evidenced by low level
water vapor imagery across our SC zones.
Varying amounts and thickness of mid and high level clouds will
prevail, especially south of I-16 in GA where the best high
level moisture will be situated in sync with subtle mid level
impulses. Skies will average mostly clear or partly cloudy
north, partly to mostly cloudy south.
The drier air mass and winds quickly decoupling this evening
will lead to better radiational cooling where cloud cover
remains limited. Thus expect overnight lows down into the mid
and upper 60s most places inland from US-17, 70-75F along the
coast, in downtown Charleston and near Lake Moultrie.
There appears to be some risk of fog after 2 or 3 am, but where
the lowest condensation pressure deficits occur (southern zones)
is where cloud cover is expected to be in greater supply. And
where skies will be more clear, it`ll be hard-pressed to achieve
cross-over values. For now no fog in the forecast, but something
that will be evaluated through the night.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
Saturday and Saturday night: The pattern aloft will be rather
diffuse with no noteworthy features poised to move through the
Southeast. At the surface, the pattern will be quite weak as well,
with subtropical high pressure over the Atlantic helping to drive
onshore southeasterly flow. Overall, the environment isn`t very
impressive for convective development, especially along the coast.
Instead, convection is expected to remain mainly inland thanks to
the onshore flow and progressive sea breeze. Even still, convection
will be on the weaker side thanks to warm profiles and weak lapse
rates. Isolated to scattered thunderstorms are in the forecast,
mainly for the inland tier near the Midlands. No real concerns
overnight as well. Temperatures are expected to be near 90 for highs
and within a couple degrees of 70 for lows.
Sunday through Monday: The mid/upper level pattern will begin to
amplify and strengthen into early next week as a southern stream
trough dives across the southern plains region. Model soundings show
a slightly more conducive atmosphere for Sunday and convection
should be a little more widespread. By Monday, strengthening
southwesterly flow aloft will combine with embedded shortwave
impulses to result in much more forcing across the region. At the
surface, a cold front will become aligned across the central
Carolinas and into central Georgia. The addition of better low level
forcing as well as deeper moisture should produce considerably
better convective coverage. PoP`s have been increased into the
likely range. There is also an increased severe risk thanks to
effective shear on the order of 20 knots by the afternoon. Storm
motion should be progressive enough to preclude any excessive rain
concerns, but there will likely be locally heavy rainfall thanks to
precipitable water values around 2 inches. Temperatures will remain
a few degrees above normal through Monday.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A cold front should push close to the area early Tuesday, eventually
pushing south of the area Wednesday or Wednesday night. Some showers
and storms are expected until the front passes through, ending from
north to south as drier air moves into the area from the north. The
drier air mass should persist through Thursday before possibly
giving way to increased humidity and maybe a bit more rain Friday.
Temperatures should be at or above normal through Tuesday night
before falling slightly below normal through Thursday, then getting
back to near normal Friday.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
Little to no chance of fog around daybreak Saturday, with only
small SHRA/TSRA chances Saturday afternoon and evening. Thus VFR
conditions will rule.
Extended Aviation Outlook: Primarily VFR. Low chances for
morning fog and stratus, mainly Saturday night and Sunday. Also
chances for brief restrictions in showers and thunderstorms,
mainly Monday and Tuesday afternoon/evening.
&&
.MARINE...
Overnight: A weak cold front will dissipate over or near the
northern waters late, resulting in a relaxed pressure pattern
Southerly winds at or below 10-15 kt early on will clock around
to the SW and W at or below 10 kt after midnight, eventually to
N-NW northern waters and variable directions at around 5 kt
late. There is more swell compared to recently, but still
nothing more than a foot or two, meaning that significant wave
heights will be no greater than 2 or 3 ft.
Saturday through Wednesday: A weak pressure pattern on the western
edge of subtropical high pressure over the Atlantic will help drive
a modest onshore flow through the weekend. Winds should top out in
the 10-15 knot range. Early next week, a cold front will draw closer
to the region and the pressure gradient will tighten and support
strengthening southwesterly flow. This will especially be the case
on Monday and winds should increase into the 15-20 knot range for
most of the local waters. This increase in winds will continue
Monday night and then weaken a bit on Tuesday as the front lays
across the waters. Then, depending on the progression of the front,
winds could turn more northerly as it pushes to the south.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.
&&
$$
NEAR TERM...
SHORT TERM...
LONG TERM...RJB
AVIATION...
MARINE...
Area Forecast Discussion
National Weather Service Quad Cities IA IL
939 PM CDT Fri Jun 2 2017
.UPDATE...
Issued at 928 PM CDT Fri Jun 2 2017
With the evening update I am adding in some small precipitation
chances overnight into Saturday morning. Not overly confident
on occurrence in presence of further building of heights aloft
and weak forcing. However, continue to see a fairly persistent
signal in HRRR of some bubbling of isolated/widely scattered
convection overnight into Saturday morning mostly near and north
of I-80. This activity is likely attributed to some weak ridge
riding energy diving ese and attendant low level warm advection.
GOES 16 nighttime microphysics imagery is also showing an
increase in mid level accas over northeast IA where signal of some
isolated convective development is suggested in several hours
from now per HRRR, thus that will be the area to watch for initial
development late evening. Wouldn`t be surprised to see coverage
trend toward low end scattered by morning into northern IL
coincident with arrival of MN ridge riding energy. Aside from
adding pops overnight into Sat AM mainly north of I-80, not much
change with only minor tweaks to lows.
&&
.SYNOPSIS...
Issued at 240 PM CDT Fri Jun 2 2017
18Z surface data has an inferred warm front, based on moisture,
running from southern Illinois northwest into north central Iowa.
Dew points east of the front were in the 40s and 50s. West of the
front, dew points were in the 60s.
&&
.SHORT TERM...(This Evening through Saturday)
ISSUED AT 238 PM CDT Fri Jun 2 2017
Summer-like temperatures, dry conditions, and low humidity levels
will be seen across the area through sunset.
Tonight, mainly dry conditions will be seen across the area as
humidity levels slowly creep up. Temperatures will be warmer than
normal.
The overall forcing tonight is quite weak and the better moisture
return is generally across the western two thirds of Iowa. However,
there will be a layer of unstable air aloft across the area. What
weak forcing that is present combined with the gradually increasing
moisture might allow a rogue shower or thunderstorm to develop prior
to sunrise, similar to what happened in southwest and south central
Iowa last night. Unlike last night, the overall forcing is much
weaker.
On Saturday, moisture will slowly increase during the day across the
area. For the more sensitive individuals, it will feel humid.
Forcing remains weak to neutral during the morning hours so mainly
dry conditions should be seen. However, if a nocturnal shower or
thunderstorm develops over the area, it would continue during the
morning before dissipating.
Diurnal heating on Saturday combined with the increased moisture
should allow isolated to potentially scattered showers and
thunderstorms to develop starting around mid day and continuing
through the afternoon. Temperatures will average above normal for
Saturday.
.LONG TERM...(Saturday Night through Friday)
ISSUED AT 238 PM CDT Fri Jun 2 2017
A weak frontal boundary will drop southeast through the forecast
area Saturday night. The issue of boundary layer moisture being
overdone by most model guidance continues. Weak convergence, deep
layer shear and forcing suggest showers and storms will remain
limited in coverage, and mainly impact northeast portions of the
forecast area. Forecast soundings with inverted-V profiles indicate
isolated gusty winds would be the main issue. The Highway 20
corridor from Dubuque to Freeport remains in the day 2 marginal risk
area, and the severe risk looks minimal.
Sunday, westerly WAA ahead of another cool front will boost
afternoon temperatures into the mid to upper 80s. Cannot rule out an
isolated storm brushing the far east or far south in the
afternoon/evening, but shear/instability/moisture look more
favorable to the east of the forecast area.
Early next week, an upper ridge to the west will drift eastward,
keeping the forecast area dry with near normal temps. More storms
are most favored Wednesday night with a loose GFS/ECMWF consensus on
a fropa in that time period. Otherwise, expect mainly dry conditions
and continued seasonal temps Thursday and Friday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday Evening)
ISSUED AT 550 PM CDT Fri Jun 2 2017
A stray shower or weak storm cannot be ruled out after midnight
through sunrise Saturday, and again mid to late Saturday
afternoon. Probability of impacting terminal quite low due to
sparse coverage and therefore continue to omit any mention.
Aside from any isolated convection expect vfr conditions. Light
southerly winds tonight will turn southwest and increase to 10-15 kts
by Saturday afternoon.
&&
.HYDROLOGY...
Issued at 1028 AM CDT Fri Jun 2 2017
A broad, roughly 24-hour crest on the Mississippi River has made
it downstream Gladstone/Burlington area with Keokuk and Gregory
Landing also near crest now. The river continues to fall at points
north of Gladstone.
Isolated thunderstorms are possible through Saturday night, but
very minimal or no impact is expected on river levels, as the
downward trend continues through next week.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...McClure
SYNOPSIS...08
SHORT TERM...08
LONG TERM...RP Kinney
AVIATION...McClure
HYDROLOGY...RP Kinney
Area Forecast Discussion
National Weather Service Lincoln IL
934 PM CDT Fri Jun 2 2017
.UPDATE...
Issued at 915 PM CDT Fri Jun 2 2017
Another pleasant day across central Illinois with plenty of
sunshine and afternoon temperatures well into the 80s with
our warmest readings at Springfield and Flora, both reached
89 degrees. Dew points once again were in the comfortable range
this afternoon with areas across the north and east seeing mid
to upper 40s, while over far western Illinois, the mid to late
afternoon dew points rose to near 60 degrees. One more comfortable
night as temperatures drop off into the upper 50s over our extreme
eastern counties, closer to the weak surface high, with mid 60s
forecast over west central Illinois.
A light southerly flow will continue to bring an increase in low
level moisture north into the area through Saturday which should
increase the cumulus clouds across the area along with a slight
chance for a thunderstorm. In the short term, the HRRR model has
been consistenly showing some isolated showers and thunderstorms
trying to develop a bit further southeast well after midnight
along a stalled frontal boundary which stretched from northern
Iowa southeast into extreme west central Illinois. May add a
slight chance for a shower or thunderstorm into our far northwest
counties well after midnight. More organized convection has
developed out across the Northern Plains this evening on the nose
of a developing low level jet with the storms expected to shift
southeast into northern Illinois by morning. A few of those may
approach our far northern counties in the morning before
dissipating with any left over mesoscale boundaries enough to
bring the threat for an isolated afternoon thunderstorm, again,
mainly across the north.
It will certainly feel more like Summer tomorrow afternoon as
temperatures climb once again into the mid to upper 80s, but with
higher humidity values making it feel more like early June. Making
the aforementioned POP adjustment across our far northwest counties
for late tonight, otherwise, the rest of the forecast is in good
shape. We should have the update out by 940 pm.
&&
.SHORT TERM...(This evening through Saturday)
ISSUED AT 247 PM CDT Fri Jun 2 2017
19z/2pm satellite/radar loops show isolated convection developing
from central Iowa southward into Missouri where sufficient moisture
return has allowed surface dewpoints to climb well into the 60s.
Meanwhile further northeast, a well-mixed and thus very dry airmass
characterized by dewpoints in the 40s is noted across the KILX CWA.
As surface winds gradually become more southerly, boundary layer
moisture will be on the increase over the next 24 hours...but this
will be a slow process. Models continue to suggest nocturnal
convection will develop further northwest across the Upper Midwest
tonight. Temp/moisture advection maximizes across Minnesota into
northwest Wisconsin on the nose of a 30-35kt 850mb jet between 06z
and 09z. This is the likely genesis region of a cluster of
thunderstorms late tonight, which is even further north than seen on
previous model runs. Given this clear northern trend and the
continued dry airmass in place locally, have removed slight chance
PoPs across the far north overnight in favor of a dry forecast
across the board. Low temperatures will be warmer than in recent
nights, with readings generally in the lower to middle 60s...except
upper 50s near the Indiana border. Synoptic forcing will remain
weak through Saturday evening, and with any mesoscale boundaries
from overnight convection staying well to the north, think rain
chances are slim to none on Saturday. Will carry just a slight
chance PoP across the Illinois River Valley during the afternoon,
but think most areas will remain dry. High temperatures will climb
into the middle to upper 80s.
.LONG TERM...(Saturday night through Friday)
ISSUED AT 247 PM CDT Fri Jun 2 2017
Cold front currently across the western Dakotas will gradually
settle southeastward into Illinois by Sunday. While southerly flow
ahead of the boundary will allow for some moisture return, overall
deep-layer moisture will be minimal. In fact, NAM/GFS precipitable
water values only increase to 1.25-1.50 ahead of the front. With
marginal moisture levels, the strongest upper dynamics remaining to
the north across the Great Lakes, and only weak convergence along
the front...think widespread rainfall is unlikely. As a result,
have lowered PoPs...with the best rain chances developing
along/south of I-72 Sunday afternoon and evening.
Once the front passes, a cooler/drier airmass will arrive early next
week. All models feature a pronounced upper trough digging over
the Northeast CONUS, resulting in northerly flow across the Midwest.
Canadian high pressure building southward into the region will
provide mostly clear skies Monday through Wednesday, with highs in
the upper 70s and lower 80s and overnight lows in the 50s. An upper
low is progged to drop southward through eastern Canada late in the
week, re-enforcing the mean trough over New England. As it does, it
will push another weak cold front southward toward Illinois. How
far south this boundary sinks before eventually stalling/washing out
remains in question: however, model consensus suggests the next
chance for showers/thunder will arrive on Thursday as the front
approaches. Temperatures will remain near normal for this time of
year in the upper 70s and lower 80s through the end of the week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 605 PM CDT Fri Jun 2 2017
VFR conditions are expected to continue through this forecast
period. High pressure will continue to move off to our east
tonight with a light southerly flow expected to draw a bit more
low level moisture north into our area. Forecast soundings suggest
some scattered clouds may move in across the west later this
evening, roughly after 05z with bases in the 5000-6000 foot range.
On Saturday, a cold front, currently across the Dakotas, will edge
slowly southeast and approach the upper Midwest and Great Lakes
region late in the day bringing scattered convection to areas well
to our north. A few models bring some convection south into
northern IL by tomorrow morning, but again, mainly to the north
of our TAF sites.
Low level moisture will continue to slowly increase across the
area on Saturday so we should see at least some scattered high
based cumulus form with bases in the 5000-6000 foot range. It
still appears any TSRA chances will hold off until after this
forecast period. Light and variable winds tonight will become
southwest on Saturday with speeds of 10 kts or less.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Smith
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Smith
Area Forecast Discussion
National Weather Service Norman OK
941 PM CDT Fri Jun 2 2017
.DISCUSSION...
Similar to last night, most of the precipitation has dissipated
across the western third of Oklahoma and western north Texas
this evening. Compared with last night, PW values overall are
much higher along with extensive cloud cover.
Recent runs of the HRRR develop showers and storms mainly across
the northern half of Oklahoma after midnight/2am, with other
storms in south central Oklahoma by sunrise. The 00z NAM12 is also
bullish with rain and storms overnight in northern Oklahoma.
Expect showers and storms will reform overnight or certainly
by sunrise Saturday, but not overly certain on a preferred
area. Remnant MCV may help with redevelopment across the northern
half of Oklahoma. Regardless, slow moving storms or showers will
be very efficient at producing very heavy rain and more flooding
is certainly possible later tonight into Saturday.
&&
.PREV DISCUSSION... /issued 256 PM CDT Fri Jun 2 2017/
DISCUSSION...
Spatial coverage of convection continues to be the biggest forecast
challenge. This is typical when weak synoptic scale forcing and
fairly weak winds aloft occur in a very moist and modestly unstable
environment. Convective-scale processes such as MCVs and
boundaries will probably be present across some parts of the area
for much of the next couple of days. There have been some fairly
minor synoptic-scale trends in model guidance that necessitate
slightly greater coverage of higher precipitation probabilities
on Sunday. We`ll detail this below. Otherwise, changes to the
forecast were relatively minor.
Latest experimental GOES-16 water vapor imagery channels clearly
show a plume of deep moisture streaming northward from the Rio
Grande Valley across Texas into Oklahoma. Checking a few GPS
precipitable water sites across north Texas shows anomalous values
around 1.90 inches which are well above the 90th percentile on
SPC`s sounding climatology page using the Fort Worth site.
Persistent clouds and cool temperatures have resulted in weak
instability. With weak deep layer shear, storm intensity has been
fairly low. Heavy rain and potential localized flooding will be
the main hazard today and tonight. A similar
kinematic/thermodynamic profile is expected tomorrow and
convection will develop across the area again with a locally heavy
rain/flooding threat.
Weak mid-upper low will move slowly east across the area through
Saturday, and then deepen a little more than previous model runs
showed on Sunday. Upper flow pattern becomes northwesterly (albeit
weak) next week. Convection that initiates in the Rockies could
move southeast into at least northwestern portions of the area.
We kept the broad brush approach with precipitation chances until
we see more agreement among medium range guidance.
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 65 80 66 81 / 50 50 50 50
Hobart OK 65 81 65 83 / 50 50 50 40
Wichita Falls TX 67 83 67 83 / 60 50 50 50
Gage OK 62 78 62 83 / 40 40 40 30
Ponca City OK 64 80 65 83 / 20 50 40 40
Durant OK 67 83 68 83 / 50 50 50 50
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...None.
TX...None.
&&
$$