Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/19/16
Area Forecast Discussion
National Weather Service Little Rock AR
653 PM CDT WED MAY 18 2016
.AVIATION...
Clouds have continued to scatter out within the past two hours
with VFR conditions being seen at all TAF sites except for KHOT.
Some precipitation will push into western Arkansas around
18z...and at this point have only included VCSH at KHOT and KADF.
Do believe the precipitation will hold off until after 00z for the
remainder of the TAF sites.
&&
.PREV DISCUSSION... /ISSUED /
SHORT TERM...Tonight through Friday night...
Shortwave over the Southwestern US will continue to move eastward
during the short term, eventually moving over the forecast area late
Friday. In the interim several minor impulses will likely be
ejected out ahead of the wave across Arkansas.
At the surface, the boundary to the south will move back to the
north and stall during the short term, and will set up a focal point
for rainfall with the shortwave approaching, with general rainfall
amounts likely maxing out in the 0.75 to 1.00 inch range. I have
highest POPs Thursday night thru Friday morning.
Long Term...Friday night through Tuesday...
Persistence troughing across the western third of the US will
make for a challenging forecast late in the extended periods.
Models are in good agreement in advertising a brief period of
ridging, both at the surface and aloft, for this weekend. So,
mostly clear skies with mild to warm days and cool nights expected
Friday night through Monday.
A return to southerly surface flow on Monday will allow for low
level moisture to surge back into the area. By late Monday, a weak
pacific cold front will be approaching from the west in association
with a very weak disturbance embedded in the southwest flow aloft.
This will bring, what appears to be a decent chance, for a round of
shower and thunderstorms Monday night and Tuesday. Rain chances are
likely to continue into Wed as well. At this point, the threat for
severe weather looks minimal.
Temperatures will generally remain at or below normal through the
period. Although as moisture returns early next week, min temps will
moderate quite a bit. Afternoon temps early next week will edge into
the lower to mid 80s but with noticably increased humidity levels.
&&
.LZK Watches/Warnings/Advisories...NONE.
&&
$$
Aviation...65
Area Forecast Discussion
National Weather Service Little Rock AR
225 PM CDT WED MAY 18 2016
.SHORT TERM...Tonight through Friday night...
Shortwave over the Southwestern US will continue to move eastward
during the short term, eventually moving over the forecast area late
Friday. In the interim several minor impulses will likely be
ejected out ahead of the wave across Arkansas.
At the surface, the boundary to the south will move back to the
north and stall during the short term, and will set up a focal point
for rainfall with the shortwave approaching, with general rainfall
amounts likely maxing out in the 0.75 to 1.00 inch range. I have
highest POPs Thursday night thru Friday morning.
&&
.Long Term...Friday night through Tuesday...
Persistence troughing across the western third of the US will
make for a challenging forecast late in the extended periods.
Models are in good agreement in advertising a brief period of
ridging, both at the surface and aloft, for this weekend. So,
mostly clear skies with mild to warm days and cool nights expected
Friday night through Monday.
A return to southerly surface flow on Monday will allow for low
level moisture to surge back into the area. By late Monday, a weak
pacific cold front will be approaching from the west in association
with a very weak disturbance embedded in the southwest flow aloft.
This will bring, what appears to be a decent chance, for a round of
shower and thunderstorms Monday night and Tuesday. Rain chances are
likely to continue into Wed as well. At this point, the threat for
severe weather looks minimal.
Temperatures will generally remain at or below normal through the
period. Although as moisture returns early next week, min temps will
moderate quite a bit. Afternoon temps early next week will edge into
the lower to mid 80s but with noticably increased humidity levels.
&&
.PRELIMINARY POINT TEMPS/POPS...
Batesville AR 51 72 55 73 / 10 20 60 40
Camden AR 56 72 59 77 / 20 60 80 50
Harrison AR 48 69 52 70 / 10 20 50 30
Hot Springs AR 55 69 58 74 / 20 50 70 40
Little Rock AR 56 73 59 74 / 10 40 80 40
Monticello AR 57 74 61 76 / 20 40 80 50
Mount Ida AR 53 69 55 74 / 20 50 70 30
Mountain Home AR 49 71 53 72 / 10 20 60 30
Newport AR 53 73 57 74 / 10 20 70 40
Pine Bluff AR 55 72 60 74 / 10 40 80 50
Russellville AR 54 72 56 75 / 10 40 60 30
Searcy AR 52 72 57 73 / 10 20 70 50
Stuttgart AR 56 72 60 74 / 10 30 80 50
&&
.LZK Watches/Warnings/Advisories...NONE.
&&
$$
Short Term...53 / Long Term...32
Area Forecast Discussion
National Weather Service Little Rock AR
853 AM CDT WED MAY 18 2016
.UPDATE...
Made a few tweaks to the POP and weather grids based on current
trends and HRRR model trends for precipitation today. For the
most part I upped precip chances across the south and introduced
some POPs in the central and northeast areas.
Going to take a look at temps here next and see if any updates are
needed. With significant cloud cover and cool morning temps I may
have to make some adjustments. 53
&&
.PREV DISCUSSION...
AVIATION...
Ifr conditions continue at this hour in the wake of a cold front
that moved through last evening. Conditions will gradually
become vfr with time but skies will never completely clear out.
Winds will be light and from the north to northeast. Lower clouds
will begin to spread back in at most terminals late in the period
as the next system approaches.
&&
SHORT TERM...Wednesday through Thursday night.
Latest surface analysis shows the cold front that moved through the
state Tuesday evening is now located over northern Louisiana. Upper
flow has turned to the north in its wake with surface high pressure
located over the upper Midwest. Considerably drier air has spread
over the state with dew point temperatures roughly 15 degrees lower
before the fropa.
A weak impulse moving through the upper flow may kick off a shower
or two this morning over the south but otherwise conditions will
be mainly dry through tonight.
Meanwhile...upper level low pressure which is clearly visible on
moisture channel imagery this morning, will morph into more of an
open wave configuration and start to head east tonight. Upper flow
will turn southwest with moisture on the increase once again. With
the aforementioned front remaining to the south of the state, an
overrunning pattern will develop, aided by an upper impulse kicking
out of the trough.
As a result...showers and thunderstorms are expected to develop over
the area Thursday and into Thursday night. Northerly flow today and
developing precipitation with extensive cloud cover Thursday will
keep temperatures below normal levels through the period.
LONG TERM...Friday through Tuesday
An upper trough will be over the plains to begin the long term
period with a weak ridge over the Rockies and strong upper low over
the west coast. By Saturday night, the ridge builds over the plains
and the respective troughs will be along the coasts. The upper ridge
will be over Arkansas Monday night but will move east Tuesday.
Low pressure moving along a warm front will bring a chance of
showers and thunderstorms Friday. Surface high pressure moves into
the area for the weekend for dry weather. Rain chances then return
Monday night through Tuesday as a short wave moves through the state.
Temperatures will generally be below normal through the period.
&&
.LZK Watches/Warnings/Advisories...NONE.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service New Orleans LA
310 PM CDT TUE MAY 17 2016
.SHORT TERM...
Active weather period continues across the forecast area. Radar
imagery over the last few hours shows quite a jump in intensity
along with coverage as daytime heating warmed the surface. Most of
the storms remain in the warm sector south of the stall frontal
boundary that was draped along a line from near Baton Rouge to
Hattiesburg. The GFS shows activity shifting south and east
through the rest of this afternoon as the very weak upper trough
that initialized the convection shifts east. The HRRR shows the
same depiction and this also matches up well with current radar
trends. So have increased pops over SELA and coastal MS through
the remainder of the afternoon and significantly dropped rain
chances for late this evening and overnight to slight chance as
little if any showers expected with drier mid level air moving in.
The main threat thru the afternoon will still be water spouts and
isolated tornadoes, mainly near the coastline. Although there`s
not a lot of strong wind in the mid and upper levels, there is
sufficient low level vertical and horizontal shear to potentially
see these hazards in the coastal waters and adjacent land areas.
Areas west of I-55 will not see much in the way of convection,
just a few showers.
.LONG TERM...
The lull in rain will carry over into Wednesday morning as there
will be not be as much lift from any upper level features to
enhance convection. However, daytime heating and possibly residual
frontal boundary could induce afternoon showers and storms. So, went
with 40 to 50% coverage during that period. Thursday does not look
all that different locally and thus kept the same or slightly higher
rain chances.
Friday still looks to be the most active day of the forecast period
as a more significant upper level trough tracks across the southern
plains and mid Mississippi Valley. Exactly when the widespread
showers begins in still not completely certain but current models
show something similar to yesterday with convection moving in from
the Gulf of Mexico/SW LA and spreading across the entire forecast
area. The widespread activity will likely last through Friday
afternoon and thus have carried likely pops through then. How much
rain is still uncertain at this time. The ECMWF shows maybe an inch
for most places. The GFS indicates a number much much higher than
that. Realistically thinking in the neighborhood of 1 to 4 inches
with isolated higher amounts. If this trend continues, flash flood
watch may be needed for Friday.
The upper level trough will amplify as it tracks east across the
United States Saturday and Sunday. Post trough cold front will usher
in drier air and likely keep the region rain free. So, have dropped
rain chances for those days. Some nice and slightly cooler mornings
will be possible as well.
MEFFER
&&
.AVIATION...
Scattered SHRA and TSRA this afternoon with most of the activity
east of Interstate 55 at this time. Most terminals with MVFR
ceilings this afternoon. Precipitation occasionally reducing
visibilities to 1SM. Expect most of the convection to weaken and/or
dissipate near sunset. May see some improvement to VFR conditions
during the evening hours, but should return to IFR/MVFR ceilings
around 09Z. Should see MVFR ceilings after 15z Wednesday...with
potential for scattered convection Wednesday afternoon. This will be
addressed in the 00Z TAF package. 35
&&
.MARINE...
Current marine issue is waterspout potential over the tidal lakes
and sounds. This should die out with convection this evening. Winds
should ease tonight with the departure of the upper impulse
currently moving across southern Mississippi and Louisiana. Will
allow Exercise Caution headline to expire...although it may be
borderline for another hour or two.
Should be a light wind regime until Thursday night when front
approaches from the northwest. Likely to need headlines at that time
over much of the coastal waters into Friday. Relatively quiet
conditions after Friday for the weekend. 35
&&
.DECISION SUPPORT...
DSS code: Blue.
Deployed: None.
Activation: None.
Activities: Monitoring convection.
Decision Support Services (DSS) Code Legend
Green = No weather impacts that require action.
Blue = Long-fused watch, warning, or advisory in effect or
high visibility event.
Yellow = Heightened impacts with short-fused watch, warning
or advisory issuances; radar support.
Orange = High Impacts; Slight to Moderate risk severe; nearby
tropical events; HazMat or other large episodes.
Red = Full engagement for Moderate risk of severe and/or
direct tropical threats; Events of National Significance.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 65 82 65 84 / 20 50 20 60
BTR 68 83 68 84 / 20 50 20 60
ASD 69 84 70 85 / 20 50 20 50
MSY 72 83 72 83 / 20 40 20 50
GPT 69 83 70 84 / 20 40 20 40
PQL 69 84 69 85 / 20 40 20 40
&&
.LIX Watches/Warnings/Advisories...
LA...None.
GM...None.
MS...None.
GM...None.
&&
$$
Area Forecast Discussion
National Weather Service Little Rock AR
653 PM CDT WED MAY 18 2016
.AVIATION...
Clouds have continued to scatter out within the past two hours
with VFR conditions being seen at all TAF sites except for KHOT.
Some precipitation will push into western Arkansas around
18z...and at this point have only included VCSH at KHOT and KADF.
Do believe the precipitation will hold off until after 00z for the
remainder of the TAF sites.
&&
.PREV DISCUSSION... /ISSUED /
SHORT TERM...Tonight through Friday night...
Shortwave over the Southwestern US will continue to move eastward
during the short term, eventually moving over the forecast area late
Friday. In the interim several minor impulses will likely be
ejected out ahead of the wave across Arkansas.
At the surface, the boundary to the south will move back to the
north and stall during the short term, and will set up a focal point
for rainfall with the shortwave approaching, with general rainfall
amounts likely maxing out in the 0.75 to 1.00 inch range. I have
highest POPs Thursday night thru Friday morning.
Long Term...Friday night through Tuesday...
Persistence troughing across the western third of the US will
make for a challenging forecast late in the extended periods.
Models are in good agreement in advertising a brief period of
ridging, both at the surface and aloft, for this weekend. So,
mostly clear skies with mild to warm days and cool nights expected
Friday night through Monday.
A return to southerly surface flow on Monday will allow for low
level moisture to surge back into the area. By late Monday, a weak
pacific cold front will be approaching from the west in association
with a very weak disturbance embedded in the southwest flow aloft.
This will bring, what appears to be a decent chance, for a round of
shower and thunderstorms Monday night and Tuesday. Rain chances are
likely to continue into Wed as well. At this point, the threat for
severe weather looks minimal.
Temperatures will generally remain at or below normal through the
period. Although as moisture returns early next week, min temps will
moderate quite a bit. Afternoon temps early next week will edge into
the lower to mid 80s but with noticably increased humidity levels.
&&
.LZK Watches/Warnings/Advisories...NONE.
&&
$$
Aviation...65
Area Forecast Discussion
National Weather Service Little Rock AR
225 PM CDT WED MAY 18 2016
.SHORT TERM...Tonight through Friday night...
Shortwave over the Southwestern US will continue to move eastward
during the short term, eventually moving over the forecast area late
Friday. In the interim several minor impulses will likely be
ejected out ahead of the wave across Arkansas.
At the surface, the boundary to the south will move back to the
north and stall during the short term, and will set up a focal point
for rainfall with the shortwave approaching, with general rainfall
amounts likely maxing out in the 0.75 to 1.00 inch range. I have
highest POPs Thursday night thru Friday morning.
&&
.Long Term...Friday night through Tuesday...
Persistence troughing across the western third of the US will
make for a challenging forecast late in the extended periods.
Models are in good agreement in advertising a brief period of
ridging, both at the surface and aloft, for this weekend. So,
mostly clear skies with mild to warm days and cool nights expected
Friday night through Monday.
A return to southerly surface flow on Monday will allow for low
level moisture to surge back into the area. By late Monday, a weak
pacific cold front will be approaching from the west in association
with a very weak disturbance embedded in the southwest flow aloft.
This will bring, what appears to be a decent chance, for a round of
shower and thunderstorms Monday night and Tuesday. Rain chances are
likely to continue into Wed as well. At this point, the threat for
severe weather looks minimal.
Temperatures will generally remain at or below normal through the
period. Although as moisture returns early next week, min temps will
moderate quite a bit. Afternoon temps early next week will edge into
the lower to mid 80s but with noticably increased humidity levels.
&&
.PRELIMINARY POINT TEMPS/POPS...
Batesville AR 51 72 55 73 / 10 20 60 40
Camden AR 56 72 59 77 / 20 60 80 50
Harrison AR 48 69 52 70 / 10 20 50 30
Hot Springs AR 55 69 58 74 / 20 50 70 40
Little Rock AR 56 73 59 74 / 10 40 80 40
Monticello AR 57 74 61 76 / 20 40 80 50
Mount Ida AR 53 69 55 74 / 20 50 70 30
Mountain Home AR 49 71 53 72 / 10 20 60 30
Newport AR 53 73 57 74 / 10 20 70 40
Pine Bluff AR 55 72 60 74 / 10 40 80 50
Russellville AR 54 72 56 75 / 10 40 60 30
Searcy AR 52 72 57 73 / 10 20 70 50
Stuttgart AR 56 72 60 74 / 10 30 80 50
&&
.LZK Watches/Warnings/Advisories...NONE.
&&
$$
Short Term...53 / Long Term...32
Area Forecast Discussion
National Weather Service Little Rock AR
853 AM CDT WED MAY 18 2016
.UPDATE...
Made a few tweaks to the POP and weather grids based on current
trends and HRRR model trends for precipitation today. For the
most part I upped precip chances across the south and introduced
some POPs in the central and northeast areas.
Going to take a look at temps here next and see if any updates are
needed. With significant cloud cover and cool morning temps I may
have to make some adjustments. 53
&&
.PREV DISCUSSION...
AVIATION...
Ifr conditions continue at this hour in the wake of a cold front
that moved through last evening. Conditions will gradually
become vfr with time but skies will never completely clear out.
Winds will be light and from the north to northeast. Lower clouds
will begin to spread back in at most terminals late in the period
as the next system approaches.
&&
SHORT TERM...Wednesday through Thursday night.
Latest surface analysis shows the cold front that moved through the
state Tuesday evening is now located over northern Louisiana. Upper
flow has turned to the north in its wake with surface high pressure
located over the upper Midwest. Considerably drier air has spread
over the state with dew point temperatures roughly 15 degrees lower
before the fropa.
A weak impulse moving through the upper flow may kick off a shower
or two this morning over the south but otherwise conditions will
be mainly dry through tonight.
Meanwhile...upper level low pressure which is clearly visible on
moisture channel imagery this morning, will morph into more of an
open wave configuration and start to head east tonight. Upper flow
will turn southwest with moisture on the increase once again. With
the aforementioned front remaining to the south of the state, an
overrunning pattern will develop, aided by an upper impulse kicking
out of the trough.
As a result...showers and thunderstorms are expected to develop over
the area Thursday and into Thursday night. Northerly flow today and
developing precipitation with extensive cloud cover Thursday will
keep temperatures below normal levels through the period.
LONG TERM...Friday through Tuesday
An upper trough will be over the plains to begin the long term
period with a weak ridge over the Rockies and strong upper low over
the west coast. By Saturday night, the ridge builds over the plains
and the respective troughs will be along the coasts. The upper ridge
will be over Arkansas Monday night but will move east Tuesday.
Low pressure moving along a warm front will bring a chance of
showers and thunderstorms Friday. Surface high pressure moves into
the area for the weekend for dry weather. Rain chances then return
Monday night through Tuesday as a short wave moves through the state.
Temperatures will generally be below normal through the period.
&&
.LZK Watches/Warnings/Advisories...NONE.
&&
$$
Area Forecast Discussion
National Weather Service Little Rock AR
305 AM CDT THU MAY 19 2016
SHORT TERM...Thursday through Friday night.
Biggest change this morning versus the past several concerns the
speed of the next shortwave expected to impact the area. All short
term / high resolution models continue to slow down this feature
with precipitation now not expected to reach the western sections of
the CWA until mid to possibly late afternoon. Current runs of the
hrrr and wrf seem to have initialized very well and will follow
their lead this morning. Nam solution also looks good expect for
some feedback concerns it seems to be experiencing regarding
rainfall.
Latest analysis shows a frontal boundary stretched along the gulf
coast and upper trough over the desert southwest. Surface high
pressure over the upper Midwest will slowly pull away while trough
reaches the south central plains by the end of the day. Impulse in
advance of the main trough will interact with this boundary to
eventually produce showers and isolated thunderstorms. No severe
weather is expected.
Models continue to delay the onset of the precipitation until this
afternoon with rain expected tonight and into early Friday when the
impulse exits to the east. Heaviest rain amounts will be across the
south closer to the front but not expecting excessive rain amounts
at this point. Will hedge on the side of caution with having seen
this pattern before where gulf coast convection robs the moisture
that otherwise one would expect.
Upper ridge will build over the region in the wake of the impulse
with dry conditions expected to round out the period. Temperatures
will continue to run below below normal but a little bit warmer than
what has been seen recently.
&&
.LONG TERM...Saturday through Wednesday
An upper ridge will be over the center portion of the country to
begin the long term period with an upper low over the west coast and
an upper trough over the east. Arkansas will be under the ridge
through the weekend then the ridge moves east on Monday. Another
ridge builds into the southern plains Tuesday from the Gulf of
Mexico as the upper low moves to the Rockies...for Tuesday and
Wednesday.
The weekend is expected to be dry with high pressure dominating.
Moisture begins to return on Monday and thunderstorm chances
increase Monday night into Tuesday as a short wave moves through the
area. Models indicate another short wave to move through the area
Wednesday...so will continue pops for Wednesday. Below normal
temperatures are expected through Monday...but will be back to near
normal Tuesday and Wednesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Batesville AR 73 56 74 55 / 10 60 40 10
Camden AR 73 60 78 59 / 50 80 40 10
Harrison AR 70 53 71 53 / 20 50 30 10
Hot Springs AR 70 59 75 59 / 50 60 30 10
Little Rock AR 74 60 75 60 / 30 70 40 10
Monticello AR 75 62 77 60 / 30 80 60 10
Mount Ida AR 70 56 75 56 / 50 50 20 10
Mountain Home AR 72 54 73 53 / 20 50 30 10
Newport AR 74 58 75 57 / 10 70 50 10
Pine Bluff AR 73 61 75 60 / 30 70 50 10
Russellville AR 73 57 76 57 / 30 50 30 10
Searcy AR 73 58 74 57 / 20 70 40 10
Stuttgart AR 73 61 75 60 / 20 70 50 10
&&
.LZK Watches/Warnings/Advisories...NONE.
&&
$$
Short Term...56 / Long Term...51
Area Forecast Discussion
National Weather Service Little Rock AR
653 PM CDT WED MAY 18 2016
.AVIATION...
Clouds have continued to scatter out within the past two hours
with VFR conditions being seen at all TAF sites except for KHOT.
Some precipitation will push into western Arkansas around
18z...and at this point have only included VCSH at KHOT and KADF.
Do believe the precipitation will hold off until after 00z for the
remainder of the TAF sites.
&&
.PREV DISCUSSION... /ISSUED /
SHORT TERM...Tonight through Friday night...
Shortwave over the Southwestern US will continue to move eastward
during the short term, eventually moving over the forecast area late
Friday. In the interim several minor impulses will likely be
ejected out ahead of the wave across Arkansas.
At the surface, the boundary to the south will move back to the
north and stall during the short term, and will set up a focal point
for rainfall with the shortwave approaching, with general rainfall
amounts likely maxing out in the 0.75 to 1.00 inch range. I have
highest POPs Thursday night thru Friday morning.
Long Term...Friday night through Tuesday...
Persistence troughing across the western third of the US will
make for a challenging forecast late in the extended periods.
Models are in good agreement in advertising a brief period of
ridging, both at the surface and aloft, for this weekend. So,
mostly clear skies with mild to warm days and cool nights expected
Friday night through Monday.
A return to southerly surface flow on Monday will allow for low
level moisture to surge back into the area. By late Monday, a weak
pacific cold front will be approaching from the west in association
with a very weak disturbance embedded in the southwest flow aloft.
This will bring, what appears to be a decent chance, for a round of
shower and thunderstorms Monday night and Tuesday. Rain chances are
likely to continue into Wed as well. At this point, the threat for
severe weather looks minimal.
Temperatures will generally remain at or below normal through the
period. Although as moisture returns early next week, min temps will
moderate quite a bit. Afternoon temps early next week will edge into
the lower to mid 80s but with noticably increased humidity levels.
&&
.LZK Watches/Warnings/Advisories...NONE.
&&
$$
Aviation...65
Area Forecast Discussion
National Weather Service Little Rock AR
225 PM CDT WED MAY 18 2016
.SHORT TERM...Tonight through Friday night...
Shortwave over the Southwestern US will continue to move eastward
during the short term, eventually moving over the forecast area late
Friday. In the interim several minor impulses will likely be
ejected out ahead of the wave across Arkansas.
At the surface, the boundary to the south will move back to the
north and stall during the short term, and will set up a focal point
for rainfall with the shortwave approaching, with general rainfall
amounts likely maxing out in the 0.75 to 1.00 inch range. I have
highest POPs Thursday night thru Friday morning.
&&
.Long Term...Friday night through Tuesday...
Persistence troughing across the western third of the US will
make for a challenging forecast late in the extended periods.
Models are in good agreement in advertising a brief period of
ridging, both at the surface and aloft, for this weekend. So,
mostly clear skies with mild to warm days and cool nights expected
Friday night through Monday.
A return to southerly surface flow on Monday will allow for low
level moisture to surge back into the area. By late Monday, a weak
pacific cold front will be approaching from the west in association
with a very weak disturbance embedded in the southwest flow aloft.
This will bring, what appears to be a decent chance, for a round of
shower and thunderstorms Monday night and Tuesday. Rain chances are
likely to continue into Wed as well. At this point, the threat for
severe weather looks minimal.
Temperatures will generally remain at or below normal through the
period. Although as moisture returns early next week, min temps will
moderate quite a bit. Afternoon temps early next week will edge into
the lower to mid 80s but with noticably increased humidity levels.
&&
.PRELIMINARY POINT TEMPS/POPS...
Batesville AR 51 72 55 73 / 10 20 60 40
Camden AR 56 72 59 77 / 20 60 80 50
Harrison AR 48 69 52 70 / 10 20 50 30
Hot Springs AR 55 69 58 74 / 20 50 70 40
Little Rock AR 56 73 59 74 / 10 40 80 40
Monticello AR 57 74 61 76 / 20 40 80 50
Mount Ida AR 53 69 55 74 / 20 50 70 30
Mountain Home AR 49 71 53 72 / 10 20 60 30
Newport AR 53 73 57 74 / 10 20 70 40
Pine Bluff AR 55 72 60 74 / 10 40 80 50
Russellville AR 54 72 56 75 / 10 40 60 30
Searcy AR 52 72 57 73 / 10 20 70 50
Stuttgart AR 56 72 60 74 / 10 30 80 50
&&
.LZK Watches/Warnings/Advisories...NONE.
&&
$$
Short Term...53 / Long Term...32
Area Forecast Discussion
National Weather Service Little Rock AR
853 AM CDT WED MAY 18 2016
.UPDATE...
Made a few tweaks to the POP and weather grids based on current
trends and HRRR model trends for precipitation today. For the
most part I upped precip chances across the south and introduced
some POPs in the central and northeast areas.
Going to take a look at temps here next and see if any updates are
needed. With significant cloud cover and cool morning temps I may
have to make some adjustments. 53
&&
.PREV DISCUSSION...
AVIATION...
Ifr conditions continue at this hour in the wake of a cold front
that moved through last evening. Conditions will gradually
become vfr with time but skies will never completely clear out.
Winds will be light and from the north to northeast. Lower clouds
will begin to spread back in at most terminals late in the period
as the next system approaches.
&&
SHORT TERM...Wednesday through Thursday night.
Latest surface analysis shows the cold front that moved through the
state Tuesday evening is now located over northern Louisiana. Upper
flow has turned to the north in its wake with surface high pressure
located over the upper Midwest. Considerably drier air has spread
over the state with dew point temperatures roughly 15 degrees lower
before the fropa.
A weak impulse moving through the upper flow may kick off a shower
or two this morning over the south but otherwise conditions will
be mainly dry through tonight.
Meanwhile...upper level low pressure which is clearly visible on
moisture channel imagery this morning, will morph into more of an
open wave configuration and start to head east tonight. Upper flow
will turn southwest with moisture on the increase once again. With
the aforementioned front remaining to the south of the state, an
overrunning pattern will develop, aided by an upper impulse kicking
out of the trough.
As a result...showers and thunderstorms are expected to develop over
the area Thursday and into Thursday night. Northerly flow today and
developing precipitation with extensive cloud cover Thursday will
keep temperatures below normal levels through the period.
LONG TERM...Friday through Tuesday
An upper trough will be over the plains to begin the long term
period with a weak ridge over the Rockies and strong upper low over
the west coast. By Saturday night, the ridge builds over the plains
and the respective troughs will be along the coasts. The upper ridge
will be over Arkansas Monday night but will move east Tuesday.
Low pressure moving along a warm front will bring a chance of
showers and thunderstorms Friday. Surface high pressure moves into
the area for the weekend for dry weather. Rain chances then return
Monday night through Tuesday as a short wave moves through the state.
Temperatures will generally be below normal through the period.
&&
.LZK Watches/Warnings/Advisories...NONE.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
657 AM CDT THU MAY 19 2016
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 322 AM CDT THU MAY 19 2016
Early this morning surface high pressure was centered just southwest
of the Great Lakes region, resulting in light southerly winds across
the forecast area. With the exception of a few mid-level clouds,
skies were mostly clear, resulting in decent radiational cooling and
early morning temperatures dropping into the mid/upper 40s by
sunrise. Despite low dewpoint depressions early this morning, do
not anticipate fog development as there isn`t much surface moisture.
However, cannot entirely rule out the potential for some isolated
areas of very shallow fog, primarily near bodies of water.
A mid-level trough was located over New Mexico this morning, and
models show this trough gradually lifting northeastward into Kansas
by this afternoon and into this evening. While there will be
increased moisture advection into the area with this approaching
wave, model soundings show only some scattered mid-level clouds by
mid to late morning with the better moisture advection and increased
cloud cover occurring during the afternoon hours. As a result,
expect temperatures to quickly rise this morning, reaching into the
60s by late morning. The temperature rises will slow down during the
afternoon with the increased cloud cover, however still expect
afternoon high temperatures to reach into the upper 60s to around 70
degrees. Expect increased lift to extend northward into the forecast
area by mid to late afternoon as the mid-level trough advances into
the area. This increased moisture and lift should support the
development of some scattered showers, possibly as early as by mid-
afternoon, with better chances during the late evening and overnight
hours as the trough tracks overhead. Models show the potential for
some weak and very shallow instability, but don`t feel it`s enough
to support thunderstorm development. The best potential for these
light rain showers will be focused across east central Kansas, with
there being some model uncertainty with just how far west these
isolated to scattered showers may develop across the forecast area.
QPF amounts should be low at around one-tenth of an inch or less.
With the overcast skies in place, expect temperatures to be a few
degrees warmer tonight with lows in the lower 50s.
.LONG TERM...(Friday through Wednesday)
Issued at 322 AM CDT THU MAY 19 2016
Upper trough till move off to the east and into Missouri by Friday
afternoon and should bring an end to the showers by late morning in
northeast and east central Kansas. An upper level ridge builds into
the Plains as an upper level low and trough gradually builds
eastward into the western U.S. Friday night and Saturday. A few
elevated showers or storms may develop within the low level jet
early Saturday across parts of western and central Kansas and may
just clip some of the southwest counties early Saturday.
Temperatures will also be on the rise as the ridge builds in and
heights rise, should see highs in the mid 70s after morning lows in
the 50s. Elevated showers or thunderstorms will be possible across
western Kansas and could clip parts of north central Kansas late
Saturday night and early Sunday. Later Sunday night storms firing
off the dryline in western Kansas as waves eject northeast out into
the Plains may maintain themselves and move into north central
Kansas and northeast Kansas. A pacific front along with the dryline
will push east and southeast into north central and southwest Kansas
by 12Z Monday morning. The frontal boundary will be a focus for
additional storms in the afternoon as another wave in the southwest
flow works its way across the Plains. Shear and instability are
favorable for strong to severe storms across parts of the area. The
boundary looks to stall or retreat westward as a stronger wave dives
southward in the base of the upper trough on Tuesday. Expect ongoing
morning convection across northeast Kansas on Tuesday with possible
redevelopment in the afternoon along the front upper level trough
will move out of the Rockies and into the Plains on Thursday.
Retreating surface high will initiate southerly flow into the
central and eastern Kansas. Lift increases in the afternoon hours as
the upper trough moves into central Kansas in the afternoon, that
combined with increasing moisture will set the stage for some light
showers to develop in the afternoon. The upper trough will move over
eastern Kansas Thursday night with the trough axis moving off into
Missouri by the afternoon hours. With weak lapse rates expect
showers primarily. An upper level ridge builds in the area Saturday
with dry weather expected along with warming temperatures. An upper
level trough will be in place across the western U.S. Sunday. A wave
is forecast to eject out of the base of the trough and clip western
Kansas. Highs pressure ridge extending from the Great Lakes
southwest into eastern Kansas on Sunday will focus the best moisture
return into the High Plains of western Kansas. Storms moving off of
the dryline may maintain and move into central Kansas late in the
day. Veering low level jet may maintain a cluster of storms which
may affect north central and northeast Kansas. Moisture and
instability axis will be focused across central and eastern Kansas
ahead of a dryline in western Kansas. A frontal boundary will move
southeast into western parts of central Kansas by Tuesday morning as
an upper level trough tracks northeast out of the Rockies and across
the Northern Plains Monday night. With southwest flow across the
Plains and ejecting waves out of the western trough expect on and
off again chances for showers and thunderstorms through Tuesday.
Shear, instability and moisture will be favorable ahead of the
dryline and frontal boundary for strong to severe storms across
eastern Kansas Monday and Tuesday. Temperatures will gradually warm
each day with highs in the 70s for the weekend and in the lower 80s
for Monday and Tuesday.ontal boundary in central Kansas. Storm
chances continue into Wednesday with the upper trough moving east
across the Rockies and into the High Plains by Thursday morning.
Wave will eject northeast across Kansas and with the frontal boundary
near the western counties expect thunderstorms to develop in the
afternoon and move northeast across the area. Temperatures are
expected to warm into the 80s for the Monday through Wednesday time
period and overnight lows primarily in the 60s.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday Morning)
Issued at 639 AM CDT THU MAY 19 2016
For the 12z TAFs, expect increasing low and mid-level cloud cover
through the day and into tonight as a system lifts northward into
the area. While cigs should remain VFR for KTOP/KFOE, model
soundings suggest that borderline MVFR/VFR cigs will be possible
overnight at KMHK. While models show scattered rain showers
developing across the area with this advancing wave, there is a
vast spread amongst the model solutions regarding (a) the timing
of precipitation lifting northward into the area, and (b) what
locations have the best potential for seeing this scattered
precipitation. Several models were holding off on these scattered
showers near the TAF sites until this evening, however recent runs
of the HRRR and RAP suggest these showers may move over the TAF
sites as early as this afternoon. Due to the uncertainty in timing
and location, only have a mention of VCSH at this time for
KTOP/KFOE.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Hennecke
LONG TERM...53
AVIATION...Hennecke
AREA FORECAST DISCUSSION
NWS SEATTLE WA
413 AM PDT THU MAY 19 2016
.SYNOPSIS...AN UPPER LOW OVER VANCOUVER ISLAND WILL BRING SHOWERS
TO WESTERN WASHINGTON AS IT MOVES ACROSS THE AREA TODAY AND INTO
WESTERN OREGON TONIGHT. THE AIR MASS WILL DRY OUT SOMEWHAT ON
FRIDAY ON THE NORTH SIDE OF THE LOW, BUT A CHANCE OF SHOWERS WILL
REMAIN IN THE FORECAST THROUGH THE WEEKEND. ANOTHER UPPER TROUGH WILL
DROP SOUTHEAST INTO THE REGION EARLY NEXT WEEK.
&&
.SHORT TERM...A 5510 METER UPPER LOW IS OVER SOUTHERN VANCOUVER
ISLAND EARLY THIS MORNING (PIC0), AND THE RESULT IS A COOL MOIST
AND WEAKLY UNSTABLE AIR MASS OVER WESTERN WASHINGTON. SCATTERED
SHOWERS CONTINUE ACROSS THE FORECAST AREA (PIC1), ESPECIALLY FROM
AROUND SEATTLE NORTHWARD IN A RATHER DISORGANIZED PUGET SOUND
CONVERGENCE ZONE. TEMPERATURES AT 3 AM WERE IN THE MID 40S TO
LOWER 50S.
THE UPPER LOW WILL MOVE SOUTH ACROSS WESTERN WASHINGTON TODAY
(PIC2) AND WESTERN OREGON TONIGHT (PIC3), REACHING NORTHERN
CALIFORNIA LATE TONIGHT. MOIST WESTERLY FLOW AND WEAK INSTABILITY
SHOULD PRODUCE SHOWERS ACROSS THE FORECAST AREA. THE FINER SCALE
MODELS AGREE THAT THE CONVERGENCE ZONE WILL MOVE SOUTH, PROBABLY
MAKING IT ALL THE WAY TO SEATAC THIS AFTERNOON. SHOWERS WILL
LIKELY DECREASE TONIGHT AS THE LOW MOVES SOUTH, AND THE
CONVERGENCE ZONE WILL PROBABLY DISSIPATE. MOISTURE WRAPPING AROUND
THE LOW WILL KEEP A CHANCE OF SHOWERS IN THE FORECAST THOUGH.
THE SNOW LEVEL WILL BE AROUND 4000 FT TODAY AND 4500 FT TONIGHT,
WITH ROUGHLY 2 TO 5 INCHES OF NEW SNOW ABOVE THE SNOW LEVEL.
THE UPPER LOW WILL MOVE SLOWLY EAST ACROSS NORTHERN CALIFORNIA ON
FRIDAY, WITH AN UPPER TROUGH AXIS EXTENDING NORTH ACROSS WESTERN
OREGON AND WASHINGTON (PIC4). FRIDAY WILL PROBABLY BEGIN CLOUDY,
BUT THE AIR MASS SHOULD DRY IN LIGHT EASTERLY FLOW. MOST OF THE
WESTERN WASHINGTON LOWLANDS SHOULD HAVE DRY OR NEARLY DRY WEATHER
FRIDAY, WITH MORNING CLOUDS GIVING WAY TO PARTLY SUNNY SKIES. WEAK
INSTABILITY WILL PRODUCE SOME LIGHT SHOWERS MAINLY OVER THE
MOUNTAINS DURING THE AFTERNOON AND EVENING. THE SNOW LEVEL WILL BE
4500 FT TO 5000 FT, BUT ONLY ANOTHER INCH OR SO OF NEW SNOW IS
EXPECTED.
THE UPPER LOW WILL PROBABLY TURN NORTHEAST INTO SOUTHEAST IDAHO
FRIDAY NIGHT AND THEN TRAVEL NORTH INTO EASTERN WASHINGTON ON
SATURDAY (PIC5). AS A RESULT, THE AIR MASS OVER WESTERN
WASHINGTON WILL REMAIN SOMEWHAT UNSTABLE WITH MOISTURE AND SHOWERS
INCREASING SATURDAY AND SATURDAY NIGHT, WITH MOST OF THE SHOWERS
AGAIN OVER THE MOUNTAINS. MCDONNAL
.LONG TERM...MODELS ARE NOT IN VERY GOOD AGREEMENT FOR THE
EXTENDED FORECAST PERIOD SUNDAY THROUGH WEDNESDAY. HOWEVER IT LOOKS
LIKE THE LONG WAVE UPPER TROUGH POSITION WILL REMAIN OVER THE
REGION THROUGH AT LEAST MONDAY (PIC6), WITH ANOTHER SHORTWAVE
TROUGH PROBABLY DROPPING SOUTHEAST OVER PACIFIC NORTHWEST. THE
UPPER TROUGH SHOULD BEGIN TO MOVE EAST OF THE REGION ON WEDNESDAY,
WITH A WEAK UPPER RIDGE MOVING INTO THE PACIFIC NORTHWEST OFFSHORE
WATERS (PIC7). MCDONNAL
&&
.AVIATION...AN UPPER LEVEL LOW WILL REMAIN OVER THE AREA THROUGH
FRIDAY (PIC11)(PIC12). VARIABLE FLOW ALOFT BECOMING NORTHEASTERLY
TONIGHT. LOW LEVEL ONSHORE FLOW WEAKENING TODAY AND DISSIPATING
TONIGHT.
CONVERGENCE ZONES FORMING AND DISSIPATING BETWEEN KPAE AND KSEA
TODAY WITH THE LAST OF THE CONVERGENCE DISSIPATING NEAR KSEA
TONIGHT. CEILINGS IN THE CONVERGENCE ZONES RANGING FROM 1000-2000
FEET.
OUTSIDE OF THE CONVERGENCE ZONE MULTIPLE CLOUD LAYERS BETWEEN 3000
AND 8000 FEET WITH CLEARING OVER THE SOUTH SOUND THIS MORNING.
KSEA...CONVERGENCE ZONE NEAR BUT MOSTLY NORTH OF THE TERMINAL TODAY
WITH CEILINGS 1500 TO 3000 FEET. CONVERGENCE DISSIPATING TONIGHT.
WINDS MOSTLY SOUTHERLY 4 TO 8 KNOTS. FELTON
&&
.MARINE...ONSHORE FLOW WILL WEAKEN TODAY WITH FALLING SURFACE
PRESSURE OFFSHORE (PIC13). A WEAK SURFACE LOW WILL DEVELOP OFF
VANCOUVER ISLAND TONIGHT AND DRIFT OVER THE COASTAL WATERS ON
FRIDAY(PIC14). THE LOW WILL DISSIPATE FRIDAY NIGHT. LOW LEVEL
ONSHORE FLOW WILL DEVELOP ON SATURDAY (PIC15) AND CONTINUE INTO
SUNDAY (PIC16). FELTON
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 2 AM PDT FRIDAY FOR CENTRAL U.S.
WATERS STRAIT OF JUAN DE FUCA-COASTAL WATERS FROM CAPE
FLATTERY TO JAMES ISLAND 10 TO 60 NM-COASTAL WATERS FROM
JAMES ISLAND TO POINT GRENVILLE 10 TO 60 NM-COASTAL WATERS
FROM POINT GRENVILLE TO CAPE SHOALWATER 10 TO 60 NM-EAST
ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.
SMALL CRAFT ADVISORY UNTIL 3 PM PDT THIS AFTERNOON FOR COASTAL
WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM.
&&
$$
WWW.WEATHER.GOV/SEATTLE
Area Forecast Discussion
National Weather Service Seattle WA
326 AM PDT THU MAY 19 2016
.Synopsis...An upper low over Vancouver Island will bring showers
to western Washington as it moves across the area today and into
western Oregon tonight. The air mass will dry out somewhat on
Friday on the north side of the low, but a chance of showers will
remain in the forecast through the weekend. Another upper trough will
drop southeast into the region early next week.
&&
.SHORT TERM...A 5510 meter upper low is over southern Vancouver
Island early this morning, and the result is a cool moist and
weakly unstable air mass over western Washington. Scattered
showers continue across the forecast area, especially from around
Seattle northward in a rather disorganized Puget Sound
convergence zone. Temperatures at 3 am were in the mid 40s to
lower 50s.
The upper low will move south across western Washington today and
western Oregon tonight, reaching northern California late
tonight. Moist westerly flow and weak instability should produce
showers across the forecast area. The finer scale models agree
that the convergence zone will move south, probably making it all
the way to SeaTac this afternoon. Showers will likely decrease
tonight as the low moves south, and the convergence zone will
probably dissipate. Moisture wrapping around the low will keep a
chance of showers in the forecast though.
The snow level will be around 4000 ft today and 4500 ft tonight,
with roughly 2 to 5 inches of new snow above the snow level.
The upper low will move slowly east across northern California on
Friday, with an upper trough axis extending north across western
Oregon and Washington. Friday will probably begin cloudy, but the
air mass should dry in light easterly flow. Most of the western
Washington lowlands should have dry or nearly dry weather Friday,
with morning clouds giving way to partly sunny skies. Weak
instability will produce some light showers mainly over the
mountains during the afternoon and evening. The snow level will be
4500 ft to 5000 ft, but only another inch or so of new snow is
expected.
The upper low will probably turn northeast into southeast Idaho
Friday night and then travel north into eastern Washington on
Saturday. As a result, the air mass over western Washington will
remain somewhat unstable with moisture and showers increasing
Saturday and Saturday night, with most of the showers again over
the mountains. McDonnal
.LONG TERM...Models are not in very good agreement for the
extended forecast period Sunday through Wednesday. However it looks
like the long wave upper trough position will remain over the
region through at least Monday, with another shortwave trough
probably dropping southeast over Pacific Northwest. The upper
trough should begin to move east of the region on Wednesday, with
a weak upper ridge moving into the Pacific Northwest offshore
waters. MCDONNAL
&&
.AVIATION...An upper level low will remain over the area through
Friday. Variable flow aloft becoming northeasterly tonight. Low
level onshore flow weakening today and dissipating tonight.
Convergence zones forming and dissipating between KPAE and KSEA
today with the last of the convergence dissipating near KSEA
tonight. Ceilings in the convergence zones ranging from 1000-2000
feet.
Outside of the convergence zone multiple cloud layers between 3000
and 8000 feet with clearing over the south sound this morning.
KSEA...Convergence zone near but mostly north of the terminal today
with ceilings 1500 to 3000 feet. Convergence dissipating tonight.
Winds mostly southerly 4 to 8 knots. Felton
&&
.MARINE...Onshore flow will weaken today with falling surface
pressure offshore. A weak surface low will develop off Vancouver
Island tonight and drift over the coastal waters on Friday. The low
will dissipate Friday night. Low level onshore flow will develop on
Saturday and continue into Sunday. Felton
&&
.SEW Watches/Warnings/Advisories...
WA...None.
PZ...Small Craft Advisory until 2 AM PDT Friday for Central U.S.
Waters Strait Of Juan De Fuca-Coastal Waters From Cape
Flattery To James Island 10 To 60 Nm-Coastal Waters From
James Island To Point Grenville 10 To 60 Nm-Coastal Waters
From Point Grenville To Cape Shoalwater 10 To 60 Nm-East
Entrance U.S. Waters Strait Of Juan De Fuca.
Small Craft Advisory until 3 PM PDT this afternoon for Coastal
Waters From Cape Flattery To James Island Out 10 Nm.
&&
$$
www.weather.gov/seattle
You can see an illustrated version of this discussion at
www.weather.gov/seattle/gafd/latest_webafd.html
Area Forecast Discussion
National Weather Service Spokane WA
1049 PM PDT WED MAY 18 2016
.SYNOPSIS...
A cold front will pass through the region tonight. Look for
breezy winds and scattered showers tonight and Thursday as
temperatures fall below average. A cool and showery weather
pattern is expected to persist through the weekend and into the
middle of next week.
&&
.DISCUSSION...
Evening update: There are two frontal boundary that we are
focusing on tonight. The low-level front which is responsible for
driving showers and thunderstorms this afternoon and evening is
slowing down but getting close to the WA/ID border. With the sun
setting, the intensity of the thunderstorms are decreasing but
isolated strikes, brief downpours, and wind gusts 20-30 mph remain
a possibility with any activity for the next 1-3 hours.
This front will cross through into the Idaho panhandle between
10PM and 2AM and confidence continues to increase that moderate to
heavy rain will develop. Models have been consistent with this
message for several days and the only uncertainty is exactly how
far north this cluster of precip will expand. What is remarkable
is that this will not be convective precipitation but rather
driven but the strong cold front which is showing frontogenetical
forcing values off the chart within the 850-700mb layer. Most of
the precip will depart east of my zones by 4-5AM.
The second front is just crossing the Cascades and associated with
the upper-level cold pool. This cold pool aloft will destabilize
the atmosphere and bring a renewed threat for showers and perhaps
an isolated thunderstorm in the northern Cascades, Okanogan
Highlands, and into the Waterville Plateau. This is not real
typical this time of day so confidence is somewhat wavering but
water vapor clearly shows a potent vort max dropping into NW WA
and set to track east of the Cascade Crest overnight. Rainfall
with this activity is not expected to be real heavy. /sb
&&
.AVIATION...
06Z TAFS: A cold front is currently pushing in N Idaho with
scattered showers and t-storms developing along a line from
Bonners Ferry to Coeur D Alene to Pullman and Lewiston. The
atmosphere is quickly stabilizing behind the front which leads me
to believe LWS stands the best shot for isold lightning and brief
wind gusts to 30 mph through 08z. Mod to heavy rain will incr
across the lower ID Panhandle 07-11Z impacting Lewiston 08-10z.
Look for declining cigs and potential for vis restrictions. As
this activity wanes...the focus will shift to the Cascades with widely
scattered showers and isolated t-storms redeveloping as early as
15Z but more likely aft 19Z as a cold core upper-level low comes
overhead. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 48 60 41 66 47 57 / 30 30 20 10 60 80
Coeur d`Alene 50 59 39 65 46 56 / 40 30 20 20 70 70
Pullman 48 57 38 60 44 55 / 70 20 10 30 50 60
Lewiston 56 64 46 63 50 61 / 70 20 10 30 50 60
Colville 48 64 39 72 46 59 / 40 70 30 20 70 80
Sandpoint 51 59 38 66 46 56 / 50 50 20 30 80 70
Kellogg 47 55 38 60 42 54 / 90 40 20 40 80 70
Moses Lake 50 66 42 71 48 65 / 10 20 20 10 20 50
Wenatchee 52 65 48 71 52 64 / 10 20 20 20 20 40
Omak 51 65 42 72 50 64 / 20 50 40 20 20 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
[top]
Area Forecast Discussion
National Weather Service Portland OR
854 PM PDT Wed May 18 2016
.SYNOPSIS...Cold front moved across the area this afternoon bringing
temperatures down around 10 degrees with winds shifting to
northwesterly. Still mostly dry across our area, but expect showers
to increase overnight continuing through tomorrow and Friday. Cooler
air will bring snow levels down to near the passes as well, which
means minor snow accumulations are possible on the Cascade Passes
tomorrow and Friday. Cool unsettled weather pattern likely continues
through the weekend into early next week.
&&
.SHORT TERM...Tonight through Saturday. Cold front has moved across
the area bringing temperatures down around 10 degrees with winds
shifting to northwesterly. Front didn`t bring enough moisture with it
to really produce any rainfall east of the Coast Range. Instability
and onshore flow will allow showers to pick up late tonight and
continue into the day on Thursday. Have taken out the chance of
Thunder in the forecast for tomorrow afternoon. Looking at model
soundings, though there is a marginal amount of surface-based
instability, the cooler air aloft stays more off-shore which limits
lapse rates. Whatever surface based instability there is will also be
limited by the amount of cloud cover. Right now models show the area
being pretty well socked in with cloud cover. Do think if we get some
breaks in the clouds tomorrow afternoon we could see a few more
rigorous showers with small hail, but probably not thunderstorms.
Snow levels will be lowering to around 4000-5000 ft which means we
could see minor snow accumulations on the passes tomorrow.
Upper-level troughing stays over the area through Saturday keeping
weather cool and showery. Could see a thunderstorm or two Friday
afternoon/evening in the Cascades with airmass being a bit drier so
could see some more surface-based instability. Steering flow is not
ideal though, so any thunderstorms that might develop would push back
east of the Cascades. With snow levels staying down around 4000-5000
ft, will probably see minor snow accumulations on Friday, too.
Saturday the cold pool starts to moderate a bit with snow levels
rising back above 5000 ft. Showers continue into Saturday as the
upper-level trough continues to hang over the area. -McCoy
.LONG TERM...Saturday night through Wednesday...The extended period
looks to be marked by a continued cool and unsettled pattern. Decent
agreement in the forecast models continues into early next week, with
the bulk of the energy associated with an upper level low splitting
late in the weekend and moving south. Models start to diverge on
Tuesday with the ECMWF showing another low pressure system
approaching the Pac NW while the GFS remains a little less
progressive. Nonetheless, there remains a chance of unsettled weather
next week. /64
&&
.AVIATION...Cold front moved through this evening with a short
period of gusty ~25kt winds at a few of the terminals. Winds are
already subsiding behind the front and will continue the trend
into the overnight hours. Scattered to broken CIGS in the 2500 to
3500 range will continue for most of the night with a few
scattered showers around.
KPDX AND APPROACHES...Mostly VFR cigs expected through the
overnight hours. Small chance of occasional MVFR cigs between
2500 and 3000 feet, but confidence isn`t high enough to add it to
the TAF. Shower chances are pretty low tonight, but kept VCSH in
after 06Z for isolated showers which will be moving through.
Current gusty winds should die off soon and remain light
overnight. /Bentley
&&
.MARINE...Decided to issue a small craft advisory for winds for
the overnight hours and into Thursday morning for the outer waters
as frequent gusts to 25 knots look increasingly likely. Winds will
weaken after sunrise Thursday with sub small craft advisory winds
expected through the weekend.
Swell associated with this cold front has brought seas up to ~9
feet. Occasional 10 ft seas have been observed at Buoy 89 and 29.
Not sure these 10 foot seas will stick around long enough to
warrant a small craft advisory for seas, but will need to monitor
conditions through the overnight hours. /Bentley
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...Small Craft Advisory for winds until 8 AM PDT Thursday for
Waters from Cape Shoalwater WA to Florence OR from 10 to
60 nm.
Small Craft Advisory for Rough Columbia River Bar from 2 AM to
6 AM PDT Thursday.
&&
$$
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This discussion is for Northwest Oregon and Southwest Washington
from the Cascade crest to 60 nautical miles offshore. The area is
commonly referred to as the forecast area.
Area Forecast Discussion
National Weather Service Spokane WA
512 PM PDT WED MAY 18 2016
.SYNOPSIS...
A cold front will pass through the region tonight. Look for
breezy winds and scattered showers tonight and Thursday as
temperatures fall below average. A cool and showery weather
pattern is expected to persist through the weekend and into the
middle of next week.
&&
.DISCUSSION...
Tonight...Pattern change underway as a cold front passes through the
region tonight and allows low pressure to reside for a long period
of time. As far as what this means for tonight, well the weather
will be more unsettled with a good chance of showers and perhaps
some thunderstorms. Any showers or thunderstorms that form will move
quickly from southwest to northeast at near 30 mph so any heavy
precipitation produced by them will not stay over one location for
very long and thus the potential for them causing any problems on
area burn scars is low. Gusty wind, occasional lightning, and small
hail will be the primary nuisances caused by this convection. The
forecast trends in line with most short term models which show the
highest pops occurring late tonight along and east of a line drawn
from the Blue Mountains up through Shoshone County in North Idaho.
/Pelatti
Thursday through Friday...A cool and showery weather pattern is expected
Thursday and Friday. For Thursday models show a closed low
dropping south near the south WA/north OR coast. This will result
in the best large scale lift over North Central and Northeast
Washington. This will lead to showers developing in these areas as
well as the potential for isolated afternoon and early evening
thunderstorms with uncapped CAPE of around 200-400 J/KG. A dry
slot moving across Southeast Washington into the Idaho Panhandle
combined with slightly more stable lapse rates should keep showers
more isolated in nature in this area. As the low drops south
Thursday night combined with the loss of daytime heating a
showers should gradually dissipate...especially after sunset.
Clearing overnight over NE Washington and north Idaho combined
with light winds will allow for efficient radiational cooling. The
coldest spots such as Republic and Deer Park may approach the
freezing mark. For Friday a significant wave coming around the
closed low moves into Central Idaho and western Montana in the
afternoon, possibly reaching southeast Washington and the south
Idaho Panhandle late in the day. In addition...daytime heating may
trigger showers over the mountains of the Cascades and north of
the Columbia Basin. JW
Friday night through Wednesday...the latest medium range model
runs are in pretty good agreement regarding the overall pattern
through the weekend...and then there are some differences in the
field of motion but not divergent enough to raise significant
doubts as to the overall trend for next week.
First...Friday night and Saturday will likely see a moist
deformation region rotate through the forecast area from south to
north bringing a period of stratiform light rain or frequent
showers through the day Saturday to much of the forecast
area...particularly over the Idaho Panhandle...Northeast
washington Mountains and the eastern Columbia Basin. Only the deep
basin and Cascades will escape the main axis of precipitation with
merely scattered showers. Thus Saturday looks like a grey and wet
day for much of the area with a potential for 1/2 to 3/4 of an inch
of rain through the day and temperatures much cooler than
normal...probably not breaking out of the 50s in the rainy areas.
Saturday night and Sunday the upper low pressure that has carved
into the region will begin to shift eastward...slowly...and this
slow progression may allow continued light rain over the Idaho
Panhandle through Sunday while the western zones begin to dry out.
The departure of the closed low will simply usher in a more
progressive and moist Pacific flow regime for next week. Models
differ in details and timing of follow on troughs and waves...but
both the GFS and EC suggest a continued cool...active and
occasionally breezy pattern right through the end of the extended
period. In this mainly westerly flow regime the best chance of
daily showers and possible afternoon and evening thunderstorms
will be over the orographically favorable areas of the northeast
and Idaho Panhandle...but with the potential for at least
isolated showers in the basin as well. /Fugazzi
&&
.AVIATION...
00Z TAFS: A cold front is currently pushing in Ern WA with
scattered showers and isolated t-storms developing along a line
from Republic to Moses Lake. This activity will pass through
the eastern terminals or WA/ID border between 02-05Z. Brief
downpours...wind gusts to 35 mph...infrequent lightning, and
small hail will be possible with any storms. The front will slow
down just south of Lewiston 06-10z with clusters of thunderstorms
and moderate to heavy rainfall possible. The other issue will be
gusty winds which will continue into Thursday. Widely scattered
showers and isolated t-storms redevelop aft 19Z as a cold core
upper-level low comes overhead. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 48 60 41 66 47 57 / 20 30 20 10 60 80
Coeur d`Alene 48 59 39 65 46 56 / 40 30 20 20 70 70
Pullman 47 57 38 60 44 55 / 70 20 10 30 50 60
Lewiston 53 64 46 63 50 61 / 70 20 10 30 50 60
Colville 48 64 39 72 46 59 / 40 70 30 20 70 80
Sandpoint 48 59 38 66 46 56 / 50 50 20 30 80 70
Kellogg 45 55 38 60 42 54 / 90 40 20 40 80 70
Moses Lake 50 66 42 71 48 65 / 10 20 20 10 20 50
Wenatchee 52 65 48 71 52 64 / 10 20 20 20 20 40
Omak 51 65 42 72 50 64 / 20 50 40 20 20 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Seattle WA
327 PM PDT WED MAY 18 2016
.SYNOPSIS...
An upper level low pressure system near the coast of southeastern
Alaska will drop southeastward into the area on Thursday, then
will drop into southern Oregon on Friday. Systems rotating around
the low will affect the region through the upcoming weekend.
Another upper low will drop southeast into the area by the middle
of next week.
&&
.SHORT TERM...
A sprawling vertically sitting just off the western coast of
southeastern Alaska is moving toward the area. Models all show the
upper low moving over western Washington on Thursday, then
dropping into southwestern Oregon on Friday. The main forecast
challenge in the short term is for rain chances and temperatures
on Saturday as models have difficulty placing the main center of
the upper low and a deformation zone rotating around it to the
north and northwest.
The front ahead of the incoming upper low sits from central
Vancouver Island to the Washington coastal waters this afternoon.
Onshore pressure gradients will increase late this afternoon and
evening as the front moves off to the southeast of the area. The
increased flow will produce a good increase in showers along the
west slopes of the mountains as moisture deepens, and will
produce a convergence zone initially around Skagit and north
Snohomish counties tonight that slides southward into southern
Snohomish and King counties later tonight into Thursday. Mountain
snow levels are expected to drop to about 4500 feet tonight and
4000 feet on Thursday as the cool upper low moves into the area.
Snow showers are likely on the higher Cascade passes and some
locations above 4000 feet by Thursday could see 2 to 4 inches.
While accumulations are not expected to be a problem on the
roadways, a Special Weather Statement was issued to alert people
traveling across the higher passes and into the backcountry of
hazards associated with the late season snow showers.
The 12z models all drop the center of the upper low into southern
Oregon and Northern California on Friday. With the low to the
south and the air mass somewhat unstable but with no focusing
mechanisms, Friday may not be too bad of a day in the lowlands
with only a slight chance of showers and partly sunny skies.
Convection will likely be confined to the higher terrain during
the afternoon and evening hours.
On Friday night and Saturday, models wrap a deformation zone
around the north and west sides of the upper low. The Canadian
GEM continues to be much more robust in bringing the deformation
zone westward into western Washington for a wetter and cool day
Saturday. The GFS is farthest east, taking the upper low more into
the Idaho Panhandle. The ECMWF is between the two extreme
solutions. Both the GFS and ECMWF result in warmer max
temperatures and lower pops across the area on Saturday. A model
blend was used as a first guess to the POP and temperature grids
while the ECMWF sky field was used as a first guess for cloud
cover. Confidence in the forecast for Saturday is low.
Albrecht
.LONG TERM...
A weak and dirty ridge with low level onshore flow moves across
the region later Sunday. The various model solutions suggest
rather deep marine moisture with dribs and drabs of precipitation
at times and temperatures a few degrees below Sunday and Monday.
Another upper low will likely drop into the region around the
beginning to middle of next week for a repeat of the weather late
this week. Forecasts generally follow a model consensus. Albrecht
&&
.AVIATION...
An upper level trof will settle over the region
overnight. Strong sw flow aloft will weaken and become variable
overnight. The low level flow will become strong onshore later
today and will persist overnight.
Expect areas of MVFR cigs to become more widespread overnight.
There will likely be areas of LIFR cigs/MVFR vsbys mainly within a
Puget Sound Convergence Zone (PSCZ) that will dvlp late today or
early this evening in its typical location (near the King/
Snohomish County line). The PSCZ may drift south into central
King County late tonight or early Thursday.
The mtns will be obscd at times.
KSEA...
Expect MVFR cigs to become prevalent over the terminal
about 0600 UTC. A PSCZ will dvlp late today or early this evening
near its typical location. There is a 50% chance that the PSCZ
will drift south over the terminal after 0900 UTC. If this occurs,
expect a wind shift from sw to nly. There is also a chance that
the winds over KBFI could become nly while remaining sw over the
terminal for a brief period late tonight.
&&
.MARINE...
Strong onshore flow in the wake of a cold front will gradually
weaken on Thursday due to lower pressure developing over the
coastal waters. The flow will strengthen on Friday in response to
higher pressure building over the coastal waters and falling
pressure east of the Cascades.
&&
.SEW Watches/Warnings/Advisories...
WA...None.
PZ...Small Craft Advisory from 6 PM this evening to 2 PM PDT Thursday
for Coastal Waters From Cape Flattery To James Island 10 To
60 Nm-Coastal Waters From James Island To Point Grenville
10 To 60 Nm-Coastal Waters From Point Grenville To Cape
Shoalwater 10 To 60 Nm.
Small Craft Advisory from 6 PM this evening to 9 AM PDT Thursday
for Coastal Waters From Cape Flattery To James Island Out
10 Nm.
Gale Warning until 6 AM PDT Thursday for Central U.S. Waters
Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of
Juan De Fuca.
Small Craft Advisory until 3 AM PDT Thursday for Northern Inland
Waters Including The San Juan Islands-West Entrance U.S.
Waters Strait Of Juan De Fuca.
Small Craft Advisory until 6 AM PDT Thursday for Admiralty Inlet.
&&
$$
www.weather.gov/seattle
You can see an illustrated version of this discussion at
www.weather.gov/seattle/gafd/latest_webafd.html
Area Forecast Discussion
National Weather Service Spokane WA
217 PM PDT WED MAY 18 2016
.SYNOPSIS...
A cold front will pass through the region tonight. Look for
breezy winds and scattered showers tonight and Thursday as
temperatures fall below average. A cool and showery weather
pattern is expected to persist through the weekend and into the
middle of next week.
&&
.DISCUSSION...
Tonight...Pattern change underway as a cold front passes through the
region tonight and allows low pressure to reside for a long period
of time. As far as what this means for tonight, well the weather
will be more unsettled with a good chance of showers and perhaps
some thunderstorms. Any showers or thunderstorms that form will move
quickly from southwest to northeast at near 30 mph so any heavy
precipitation produced by them will not stay over one location for
very long and thus the potential for them causing any problems on
area burn scars is low. Gusty wind, occasional lightning, and small
hail will be the primary nuisances caused by this convection. The
forecast trends in line with most short term models which show the
highest pops occurring late tonight along and east of a line drawn
from the Blue Mountains up through Shoshone County in North Idaho.
/Pelatti
Thursday through Friday...A cool and showery weather pattern is expected
Thursday and Friday. For Thursday models show a closed low
dropping south near the south WA/north OR coast. This will result
in the best large scale lift over North Central and Northeast
Washington. This will lead to showers developing in these areas as
well as the potential for isolated afternoon and early evening
thunderstorms with uncapped CAPE of around 200-400 J/KG. A dry
slot moving across Southeast Washington into the Idaho Panhandle
combined with slightly more stable lapse rates should keep showers
more isolated in nature in this area. As the low drops south
Thursday night combined with the loss of daytime heating a
showers should gradually dissipate...especially after sunset.
Clearing overnight over NE Washington and north Idaho combined
with light winds will allow for efficient radiational cooling. The
coldest spots such as Republic and Deer Park may approach the
freezing mark. For Friday a significant wave coming around the
closed low moves into Central Idaho and western Montana in the
afternoon, possibly reaching southeast Washington and the south
Idaho Panhandle late in the day. In addition...daytime heating may
trigger showers over the mountains of the Cascades and north of
the Columbia Basin. JW
Friday night through Wednesday...the latest medium range model
runs are in pretty good agreement regarding the overall pattern
through the weekend...and then there are some differences in the
field of motion but not divergent enough to raise significant
doubts as to the overall trend for next week.
First...Friday night and Saturday will likely see a moist
deformation region rotate through the forecast area from south to
north bringing a period of stratiform light rain or frequent
showers through the day Saturday to much of the forecast
area...particularly over the Idaho Panhandle...Northeast
washington Mountains and the eastern Columbia Basin. Only the deep
basin and Cascades will escape the main axis of precipitation with
merely scattered showers. Thus Saturday looks like a grey and wet
day for much of the area with a potential for 1/2 to 3/4 of an inch
of rain through the day and temperatures much cooler than
normal...probably not breaking out of the 50s in the rainy areas.
Saturday night and Sunday the upper low pressure that has carved
into the region will begin to shift eastward...slowly...and this
slow progression may allow continued light rain over the Idaho
Panhandle through Sunday while the western zones begin to dry out.
The departure of the closed low will simply usher in a more
progressive and moist Pacific flow regime for next week. Models
differ in details and timing of follow on troughs and waves...but
both the GFS and EC suggest a continued cool...active and
occasionally breezy pattern right through the end of the extended
period. In this mainly westerly flow regime the best chance of
daily showers and possible afternoon and evening thunderstorms
will be over the orographically favorable areas of the northeast
and Idaho Panhandle...but with the potential for at least
isolated showers in the basin as well. /Fugazzi
&&
.AVIATION...
18Z TAFS: Cold front passage this afternoon and evening allows
for unsettled weather in the form of showers and thunderstorms
and accompanying gusty wind, occasional lightning, and possibly
small hail in the aviation area. Best chance for the showers and
thunderstorm to occur is between 21Z Today and 8Z tonight.
/Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 48 60 41 66 47 57 / 20 30 20 10 60 80
Coeur d`Alene 48 59 39 65 46 56 / 40 30 20 20 70 70
Pullman 47 57 38 60 44 55 / 70 20 10 30 50 60
Lewiston 53 64 46 63 50 61 / 70 20 10 30 50 60
Colville 48 64 39 72 46 59 / 40 70 30 20 70 80
Sandpoint 48 59 38 66 46 56 / 50 50 20 30 80 70
Kellogg 45 55 38 60 42 54 / 90 40 20 40 80 70
Moses Lake 50 66 42 71 48 65 / 10 20 20 10 20 50
Wenatchee 52 65 48 71 52 64 / 10 20 20 20 20 40
Omak 51 65 42 72 50 64 / 20 50 40 20 20 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
1034 AM PDT WED MAY 18 2016
.SYNOPSIS...
The Inland Northwest will experience one more day of warmer than
average temperatures today, before a vigorous cold front arrives
Wednesday evening. Look for breezy winds Wednesday afternoon
through Thursday as temperatures fall below average. A cool and
showery weather pattern is expected to persist through the
weekend and into the middle of next week.
&&
.DISCUSSION...
12Z upper air sounding for Spokane shows a bit of transition
taking place ahead of an approaching cold front. Majority of
the winds aloft have now become more westerly in nature
and the lapse rates have steepened somewhat as the shortwave
ridging that kept yesterday rather dry and benign has moved
to the east. Most of the short term models suggest any
showers and thunderstorms that form this afternoon and evening
will move at a robust speed from southwest to northeast
near 30 mph. Having showers and thunderstorms move at such a
quick pace makes it unlikely heavy rainfall will linger on one
area for long. As such the potential for today`s/tonights rainfall
causing problems on recent burn scars is low. Usual spring
convection problems such as small hail, occasional lightning, and
gusty wind are possible. Grids have been modified some but zones
were not updated as the changes had no significant impact on the
wording. /Pelatti
&&
.AVIATION...
18Z TAFS: Cold front passage this afternoon and evening allows
for unsettled weather in the form of showers and thunderstorms
and accompanying gusty wind, occasional lightning, and possibly
small hail in the aviation area. Best chance for the showers and
thunderstorm to occur is between 21Z Today and 8Z tonight.
/Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 77 48 60 42 64 48 / 10 20 30 20 10 60
Coeur d`Alene 76 48 59 41 65 46 / 10 40 30 20 20 70
Pullman 74 47 57 40 62 44 / 10 70 20 10 30 50
Lewiston 81 53 64 47 65 50 / 10 70 20 10 30 50
Colville 79 48 64 41 69 46 / 20 40 70 30 20 70
Sandpoint 74 48 59 39 65 46 / 20 50 50 20 30 80
Kellogg 74 45 55 38 62 42 / 20 90 40 20 40 80
Moses Lake 81 50 67 44 69 48 / 0 10 20 20 10 20
Wenatchee 78 52 67 48 68 51 / 0 10 20 20 20 20
Omak 79 51 68 45 69 49 / 20 20 50 40 20 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
1033 AM PDT WED MAY 18 2016
.SYNOPSIS...
The Inland Northwest will experience one more day of warmer than
average temperatures today, before a vigorous cold front arrives
Wednesday evening. Look for breezy winds Wednesday afternoon
through Thursday as temperatures fall below average. A cool and
showery weather pattern is expected to persist through the
weekend and into the middle of next week.
&&
.DISCUSSION...
12Z upper air sounding for Spokane shows a bit of transition
taking place ahead of an approaching cold front. Majority of
the winds aloft have now become more westerly in nature
and the lapse rates have steapened somewhat as the shortwave
ridging that kept yesterday rather dry and benign has moved
to the east. Most of the short term models suggest any
showers and thunderstorms that form this afternoon and evening
will move at a robust speed from southwest to northeast
near 30 mph. Having showers and thunderstorms move at such a
quick pace makes it unlikely heavy rainfall will linger on one
area for long. As such the potential for today`s/tonights rainfall
causing problems on recent burn scars is low. Usual spring
convection problems such as small hail, occasional lightning, and
gusty wind are possible. Grids have been modified some but zones
were not updated as the changes had no significant impact on the
wording. /Pelatti
&&
.AVIATION...
18Z TAFS: Cold front passage this afternon and evening allows
for unsettled weather in the form of showers and thunderstorms
and accompanying gusty wind, occasional lightning, and possibly
small hail in the aviation area. Best chance for the showers and
thunderstorm to occur is between 21Z Today and 8Z tonight.
/Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 77 48 60 42 64 48 / 10 20 30 20 10 60
Coeur d`Alene 76 48 59 41 65 46 / 10 40 30 20 20 70
Pullman 74 47 57 40 62 44 / 10 70 20 10 30 50
Lewiston 81 53 64 47 65 50 / 10 70 20 10 30 50
Colville 79 48 64 41 69 46 / 20 40 70 30 20 70
Sandpoint 74 48 59 39 65 46 / 20 50 50 20 30 80
Kellogg 74 45 55 38 62 42 / 20 90 40 20 40 80
Moses Lake 81 50 67 44 69 48 / 0 10 20 20 10 20
Wenatchee 78 52 67 48 68 51 / 0 10 20 20 20 20
Omak 79 51 68 45 69 49 / 20 20 50 40 20 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
432 AM PDT WED MAY 18 2016
.SYNOPSIS...
The Inland Northwest will experience one more day of warmer than
average temperatures today, before a vigorous cold front arrives
Wednesday evening. Look for breezy winds Wednesday afternoon
through Thursday as temperatures fall below average. A cool and
showery weather pattern is expected to persist through the
weekend and into the middle of next week.
&&
.DISCUSSION...
Today through Thursday night: A vigorous frontal wave moves into
the region with the threat of showers, some thunderstorms and
breezy conditions. It will also usher in cooler than normal
temperatures by Thursday.
This morning the cold front was pushing onto the Pacific NW coast
and it is expected to shift into the Cascades this afternoon,
before crossing through the ID Panhandle tonight. This morning
expect generally dry weather but some high clouds will begin to
filter in from the west/northwest. This afternoon convective
instability increases, leading to an increasing threat of showers
and thunderstorms around the mountains. The threat expands through
all but the deeper Columbia Basin between late afternoon and
evening with the incoming cold front. The best thunder threat at
this times appear to be across the northeast WA and ID Panhandle
mountains, but at least an isolated threat will be found across
the eastern third of WA too. Late this evening and overnight the
thunder threat wanes, but the rain threat peaks across the ID
Panhandle and far southeast Washington along the stalling front
and in advance of the supporting upper shortwave. Some moderate
precipitation will be possible from the Camas Prairie to the
Central Panhandle.
Thursday a surface low deepens east of the divide and a 500mb low
comes to the Cascades. A deformation axis wraps between these two
features, across the US/Canadian border into Okanogan County and
the Waterville Plateau. This will provide one focus for moisture
and more numerous showers. This is also the region where models
depict the best instability and thunderstorm threat. With all of
this we will have to watch for some moderate rains and possible
flooding or slides around the burn scars near the Cascades, though
the focus may be a bit too far east of here to have a real impact.
In addition the cooler air with the low will drop snow levels to
near 4-5kft in the Cascades. So some light snow is possible over
some of the Cascade mountain passes, though amounts should be
light and impacts will be low.
A mid-level shortwave pivots around the east side of the
500mb low too. This will provide an secondary impetus for showers
across the remainder of the CWA. However precipitation here should
be more isolated to scattered in nature as models show a fair
amount of dry air away from the aforementioned deformation axis.
The threat of thunderstorms too will be mainly slight. By Thursday
night the mid-level shortwave in our region tracks north. A second
more vigorous shortwave pivots around backside of the 500 mb low,
drawing it toward western OR/northern CA. Overall this leaves a
weakening focus for precipitation and so the threat of showers
will be on the wane.
The other feature of the system will be the winds. Thanks to a
tightening gradient and strengthening LLJ ahead of/with the cold
front expect increasing winds through Wednesday, continuing into
Thursday. Speeds will be highest near the Cascade gaps and out
through the Columbia Basin, around 10 to 20 mph with gusts of 20
to 30 mph. /J. Cote`
Thursday through Sunday Morning...A typical springtime pattern will
grip the Inland Northwest through most of this period. This will
feature a deep upper level low which is expected to wobble over
the western US and send weak shortwave troughs into the region.
These impulses will bring increasing chances of showers and even
some thunderstorms but timing them this far out in the forecast
will likely prove futile. At least at the beginning of this period
there is some decent model agreement. Friday will likely be the
day with the least chance of precipitation as the base of the
upper level low is expected to drop into northern California.
Southerly flow on the eastern flank of the low will send an upper
level disturbance northward toward NC Idaho while weak easterly
flow will pool some moisture and instability near the Cascades.
Model CAPE values suggest potential thunder for the Cascade crest
region as well as over extreme SE WA and NC ID however limited
upper level forcing save some weak upper level divergence suggests
the thunder chances won`t be large. Model agreement is fair that
the shortwave trough moving into our SE zones will continue to
pivot counter-clockwise resulting in increasing chances of showers
and nocturnal convection through most of the Panhandle and into NE
Washington. By Saturday the base of the low will move northward
resulting in decreasing stabilization across most of the forecast
area. Once again the dynamical support for thunderstorms is
lacking, however daytime heating and SBCAPES between 400-800 j/kg
should prove enough to result in thunderstorms across the eastern
quarter of Washington and most of the Panhandle. Any thunderstorms
which form will likely be steered W-SW winds up to 10 kts. This
isn`t terribly swift but it should minimize any large risk for
flooding. Model soundings also do not suggest much potential for
any strong thunderstorms.
Sunday-Wednesday...The core of the upper level low is expected to
shift east of our forecast area and into the eastern Montana and
the Prairie Provinces, however a weak troughy pattern will remain
over the PacNW with the upper level jet still pointed into
northern California. This leaves the Inland NW on the cold side of
the jet and under a conditionally unstable air mass. Model
instability parameters pale compared to what is expected on
Saturday, however there will likely be just enough instability to
support thunder each afternoon and evening give sufficient diurnal
heating. The next deep trough of low pressure is expected to
arrive on Wednesday resulting in another increasing chance of
precipitation.
While we are fairly certain we will see showers and some
thunderstorms each day of the forecast, a better certainty is our
chances for seeing cooler than normal temperatures. Highs are
expected to reach the 60s to lower 70s and nighttime lows will
drop into the upper 30s to mid 40s. fx
&&
.AVIATION...
12Z TAFS: A cold front moves into the Cascades this afternoon and
pushes through eastern WA/north ID this evening. This will bring
an increased threat of showers around the mountains this
afternoon, maybe a thunderstorm or two. A threat of showers will
come to the eastern TAF sites late this afternoon/evening too,
retreating to the Panhandle and far southeast WA, including
PUW/LWS, overnight into Thursday morning. Primarily VFR conditions
are expected but local MVFR cigs are possible within any showers,
especially near PUW/LWS as the front stalls here. A limiting
factor to showers/clouds will be increasing winds. Winds will
start to increase after 18-22Z. Gusts near 20 kts will be
possible, except may be closer to 30 kts near EAT/MWH. /J. Cote`
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 77 48 60 42 64 48 / 10 20 30 20 20 40
Coeur d`Alene 76 48 59 41 65 46 / 10 40 30 20 20 50
Pullman 74 47 57 40 62 44 / 10 70 30 10 30 40
Lewiston 81 53 64 47 65 50 / 10 70 30 10 30 40
Colville 79 48 64 41 69 46 / 20 40 70 30 20 60
Sandpoint 74 48 59 39 65 46 / 20 50 50 20 30 60
Kellogg 74 45 55 38 62 42 / 20 90 50 20 40 50
Moses Lake 81 50 67 44 69 48 / 0 10 30 20 10 30
Wenatchee 78 52 67 48 68 51 / 0 10 30 20 20 30
Omak 79 51 68 45 69 49 / 20 20 60 40 20 40
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
445 PM PDT TUE MAY 17 2016
.SYNOPSIS...
The Inland Northwest will experience one more day of warmer than
average temperatures on Wednesday before a vigorous cold front
arrives Wednesday evening. Look for breezy winds and Wednesday
afternoon through Thursday as temperatures fall below average. A
cool and showery weather pattern is expected to persist through
the weekend.
&&
.DISCUSSION...
Tonight and Tomorrow: The cold front that will usher in our
pattern change Wednesday afternoon and evening is currently
approaching the western tip of Vancouver Island.
* Precipitation Chances: The NAM, GFS, and ECMWF continue to show
that this front will cross the Cascades in the mid to late
afternoon hours Wednesday and surge into the Idaho Panhandle
during the evening. Limited deep layer moisture and instability
will preclude widespread shower and thunderstorm development
Wednesday afternoon and evening with scattered convection over
the mountains of the Idaho Panhandle, northeast Washington, and
northeast Oregon. There is good model agreement that
precipitation will become more organized after midnight
Wednesday as the front over Oregon encounters mid- level
instability. The models advertise clusters of showers and
thunderstorms capable of a swath of a tenth to a third of an
inch of precipitation from northeast Oregon through the Camas
Prairie, Clearwater Mountains, and southern Shoshone county.
* Breezy Winds: West or southwest winds will increase Wednesday
afternoon as the cross-Cascade pressure gradient increases with
the approaching front. By mid afternoon, sustained 10 to 15 mph
winds with gusts to 20 mph are expected over the Columbia Basin,
Palouse, and West Plains. Cool maritime air surging through the
Cascade gaps will likely produce sustained west winds of 20 mph
with gusts to 30 mph tomorrow afternoon and evening in places
like Wenatchee, Chelan, and Vantage. Cold advection through
Thursday will sustain the breezy conditions with the tightest
pressure gradient in the morning. /GKoch
Thursday through Sunday Morning...A very large and intense upper
level low pressure area drops down from the Gulf of Alaska and
resides in the vicinity of Eastern Washington and North Idaho during
this time interval. There is abundant moisture and numerous
mesoscale disturbances embedded in the periphery of the low which
will drift across Eastern Washington and North Idaho and as such the
forecast calls for cool and unsettled weather with forecast
temperaturs well on the cool side of normal. Models suggest storm
motion will be rather slow at less than 15 mph for the showers and
thunderstorms that develop and this would allow for the possibility
of locally heavy rainfall in addition to the small hail, gusty wind,
and lightning.
Sunday through Tuesday: The upper level trough will remain over
the area with showers and cooler temperatures expected across the
region. Showers will likely continue across the mountains with
less of a chance down towards the Columbia Basin. Models are
showing some instability mainly across the mountains of northeast
WA and north ID each afternoon and early evening. Have extended
the thunder threat to include Sunday and now Monday and Tuesday as
well. Daytime temperatures will be about 3 to 6 degrees below
average for this time of the year. Overnight lows will be right
around average given the cloud cover. /Nisbet
&&
.AVIATION...
00Z TAFS: Upper level moisture moving in ahead of the next weather
disturbance will result in a high sct-bkn cirrus deck through 00z
tomorrow. All TAF sites will remain VFR thorugh that time. Light
and variable winds tonight will increase Wednesday
afternoon...mainly out of the southwest as a cold front
approaches. Expect sustained winds 10-20kts with gusts 20-30kts
beginning around 18-20z and lasting through Wednesday night. Tobin
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 53 77 47 61 42 65 / 0 10 30 40 30 20
Coeur d`Alene 50 76 48 59 41 65 / 0 10 40 50 40 30
Pullman 49 75 47 57 40 62 / 0 10 50 40 20 40
Lewiston 54 81 53 64 47 67 / 0 10 60 40 20 30
Colville 49 80 48 65 41 70 / 0 10 40 70 50 30
Sandpoint 48 76 48 59 40 65 / 0 10 40 50 50 30
Kellogg 45 73 45 55 38 61 / 0 10 70 50 50 50
Moses Lake 50 82 51 67 45 68 / 0 0 10 30 30 20
Wenatchee 55 78 52 67 47 69 / 0 0 10 30 30 30
Omak 52 80 51 68 46 70 / 0 10 40 50 50 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Portland OR
359 PM PDT Tue May 17 2016
.SYNOPSIS...An upper level ridge will be over the area today
for drier and warmer weather. This will be short lived, however, as
an upper low will drop south from Alaska on Wednesday and Thursday.
This will usher in a return to cool and showery weather late in the
week that will likely persist through the weekend. Snow levels will
lower on Thursday and Friday to near the Cascade pass level.
&&
.SHORT TERM...Tonight through Friday. Latest visible satellite
imagery and surface observations depict some high cirrus overhead in
the northern and western portions of the area, while generally clear
skies continue over the remaining parts of the region. Temperatures
continue to warm into the lower 60s at the coast and lower 70s
inland. Positively titled upper ridge over the Pacific Northwest will
flatten out overnight through early Thursday as a deep upper level
low pressure system begins to slide south from the Gulf of Alaska
towards the region. Expect rain chances to begin by late Wednesday
morning along the coastal areas as the low pressure system moves into
the region. Rain chances will then spread across the rest of the
region by late Wednesday as the low remains in place over the region.
Snow levels will begin initially quite high - well above 8,000 feet -
but will lower on Thursday and Friday as very cold air aloft moves
into the region. Snow levels will likely fall to around 4,500 feet.
However, as the very cold air aloft moves into the region with 500 mb
temperatures in the -25 to -27 degree C range, expect that some of
the stratiform precipitation may take on a convective mode as the
advection of cold air aloft brings instability to the atmosphere. One
likely scenario is that brief light accumulations at the Cascade
passes may occur, though with surface temperatures slightly above
freezing, any accumulation near the snow level may not linger long.
More significant accumulations - but only on the order of a few
inches - are possible at the higher Cascade elevations (i.e., above
around 5000 feet).
Another consideration on Thursday and Friday is the potential for
thunderstorms as the upper level low moves into the Pacific
Northwest. As mentioned above, H5 temperatures will cool from around
-14 C to -25 C during the day on Thursday. Forecast soundings show
that only minimal warming at the surface will be necessary to achieve
the convective temperature and the cooling aloft will introduce
plenty of instability. For this reason have introduced a slight chance
of thunder on Thursday afternoon and evening for the Coast Range and
points east. Expect to refine the area of potential thunderstorms
with future updates, as some differences to remain in the models
with respect to the evolution of the upper low and/or favored
locations for convection. Another cool and showery day in store for
Friday as little change in the overall pattern, though afternoon
and evening thunder chances remained confined to the Cascades and
foothills. /Cullen
.LONG TERM...Friday night through Wednesday. The extended period
looks to be marked by a continued cool and unsettled pattern. Decent
agreement in forecast models continues through the weekend into early
next week, with the energy associated with the upper low splitting
late Saturday with the bulk of the energy moving south and east into
the Great Basin. A brief break in rain possible late in the weekend,
but another low pressure system approaches from the Gulf of Alaska to
further increase rain chances.
&&
.AVIATION...Generally SKC this afternoon but cirrus are beginning
to move in at the coast and will spread inland through this
evening. MVFR stratus may develop tonight along the coast after
03Z and try to push up the Columbia River but likely with little
inland propagation. Cigs may not rise much Wednesday at the coast
due to cold front moving in and reinforcing cloud cover.
KPDX AND APPROACHES...Cirrus moving in this evening. Cigs lower to
around 5000 ft with approach of a front later Wednesday.
&&
.MARINE...High pressure will be over the northeast Pacific and
along the Washington and north Oregon coasts through much of the
coming week. Meanwhile, a trough of low pressure will remain
along the south Oregon coast into Tue. This will keep north winds
along the central Oregon coastal waters gusting over 20 kt again
this afternoon and into the overnight.
Upper level low pressure will move over the region for the second
half of the week through next weekend. This will tend to weaken the
winds a bit. This system will bring an initial weak cold front
through
the waters early Wednesday, although at this time it appears winds
should remain below small craft criteria. However some localized
gusts 21-25 kt out of the northwest will be possible.
Seas increase to 8 to 9 ft late Wednesday with the front with a
few spots of 10 ft. Seas will be slow to come down, finally
decreasing to 5 to 7 ft sometime Saturday. /Bowen
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...Small Craft Advisory for winds until 5 AM PDT Wednesday for
Coastal Waters from Cascade Head OR to Florence OR out 60
nm.
&&
$$
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This discussion is for Northwest Oregon and Southwest Washington
from the Cascade crest to 60 nautical miles offshore. The area is
commonly referred to as the forecast area.
Area Forecast Discussion
National Weather Service Spokane WA
1113 AM PDT TUE MAY 17 2016
.SYNOPSIS...
High pressure will bring warm, dry weather to the region today.
Wednesday breezy conditions develop for the afternoon and evening,
as a vigorous cold front moves through Washington and north
Idaho. Then cooler, showery weather is expected Thursday through
the weekend as an area of low pressure becomes anchored over our
region.
&&
.DISCUSSION...
The cold front that is scheduled to arrive tomorrow afternoon
(Wed) is currently off the Washington coast. The morning model
runs continue to show the front crossing the Cascades tomorrow
afternoon and surging through eastern Washington and north Idaho
tomorrow evening. It still looks like afternoon and evening
showers and thunderstorms will be scattered and mainly limited to
the mountains along the Canadian border, the Cascade crest, and
the Idaho Panhandle. There has been good model continuity that
late evening showers and thunderstorms will become more
concentrated over northeast Oregon and the southern Idaho
Panhandle. At this time, it looks like the Camas Prairie, the
Clearwater mountains, and southern Shoshone county will have a
good shot of a quarter to a third of an inch of rain Wednesday
night. Elsewhere, precipitation amounts Wednesday and Wednesday
night will be of the hit and miss variety.
Until the front arrives Wednesday afternoon, our region will
continue to experience above average temperatures with afternoon
highs in the 70s and low 80s today and again tomorrow. /GKoch
&&
.AVIATION...
18Z TAFS: Light winds and mainly clear skies will prevail over the
Inland Northwest today under a high pressure ridge. Bands of high
level clouds will move into the region overnight and Wednesday
morning ahead of a cold front. The front is expected to arrive
late Wednesday afternoon bringing increasing west or southwest
winds and the potential for showers Wednesday night. Shower
chances fall outside the 18z TAF period, and will be addressed in
the 00z TAF. /GKoch
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 74 53 76 49 61 42 / 0 0 10 30 40 30
Coeur d`Alene 74 50 76 49 59 41 / 0 0 10 30 50 40
Pullman 70 49 74 47 57 40 / 0 0 10 50 40 20
Lewiston 77 54 81 54 64 47 / 0 0 10 60 40 20
Colville 80 49 79 49 65 41 / 0 0 10 40 70 50
Sandpoint 74 48 75 49 59 40 / 10 0 10 30 50 50
Kellogg 71 45 73 45 55 38 / 10 0 10 70 50 50
Moses Lake 80 51 81 50 67 45 / 0 0 0 20 30 30
Wenatchee 80 55 78 52 67 47 / 0 0 0 20 30 30
Omak 80 52 80 52 68 46 / 0 0 10 50 50 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Portland OR
920 AM PDT Tue May 17 2016
.SYNOPSIS...An upper level ridge will be over the area today
for drier and warmer weather. This will be short lived as an upper
low will drop south from Alaska Wednesday and Thursday and bring a
return to cool and showery weather late in the week that will likely
persist through the weekend. Snow levels will drop Thursday and
Friday to around or just above pass level in the Cascades.
&&
.UPDATE...Latest visible satellite imagery reveals a clearing trend
across many portions of the forecast area, with a few pockets of
stratus lingering in the portions of the Willamette Valley into the
Cascades and foothills. Updated sky grids to reflect this trend, but
no other changes needed this morning with the forecast otherwise on
track.
.SHORT TERM...Today through Thursday. While a few areas of lower
clouds remain early this morning, expect these clouds to continue to
thin today as subsidence and drying develops as an upper ridge slides
over the forecast area. With plenty of sun this afternoon and high
pressure firmly in control over the region, expect a pleasant day
with temperatures warming into the mid 70s inland and around 60 at
the coast. Of note, the latest runs of the HRRR seem to indicate some
chance for light rain or sprinkles across the far northwestern
portions of the forecast area late this afternoon (from Astoria
through the Willapa Hills). However, there is very little to support
this in either satellite images or other model data. Specifically,
the lower atmosphere should remain too dry for anything to reach the
ground, even if the upper level moisture materializes. Therefore,
will stick with a dry forecast for today for this area - as well as
everywhere else. Today also looks to be the warmest day of the week
with an upper low moving from the Gulf of Alaska into the region.
This low will bring the return of showers as early as Wednesday
morning along the coast, before the showers push inland later in the
day. The low continues to drop south on Thursday, bringing
increasing rain chances and lowering snow levels. Expect to see snow
levels reach around 4500 feet, which could bring accumulating snow
to near the Cascade passes. 500 mb temperatures in the -24 to -26 C
may be enough to trigger a thunderstorm or two Thursday afternoon.
/Cullen
.LONG TERM...No Changes. Previous discussion follows...Thursday night
through Sunday...The upper low drops to over top of Oregon on Friday
which will continue shower chances. With a cold pool in place and
some decent forcing with the low, Friday looks like the best chance
this week for any thunderstorms. Have limited thunder chances to the
Cascades for now but based on the development and track of the low,
cannot rule out the possibility of thunder in the valley Friday
afternoon and evening. Will be keeping an eye on that possibility.
Snow levels remain in the 4500 to 5000 ft range through Friday.
Models are beginning to come into better agreement regarding when the
low will exit the area with both the GFS and the ECMWF showing the
energy from the low splitting late Saturday and moving out of the
local area Saturday night and into Sunday. This solution would bring
a brief break in rain chances Saturday night and possibly into Sunday
morning but at this point it looks like
additional systems will begin to move into the area Sunday, returning
to a wet pattern. Temperatures for the extended period will remain
seasonably cool with valley highs in the low to mid 60s and coastal
highs in the upper 50s to low 60s. /Bowen
&&
.AVIATION...Patchy high MVFR cigs this morning left in the
valley but mostly low VFR cigs just above 3000 ft inland. Expect
clouds across the area to clear by this afternoon for near SKC
with only some cirrus. Gusts out of the N/NW 25 kt possible KONP
this afternoon and evening. MVFR stratus may develop tonight
along the coast after 03Z and try to push up the Columbia River
but likely with less inland coverage than this morning.
KPDX AND APPROACHES...Low VFR this morning with cigs just above
3000 ft will clear by this afternoon. Then only cirrus through
Wednesday morning. /Bowen
&&
.MARINE...High pressure will be over the northeast Pacific and
along the Washington and north Oregon coasts through much of the
coming week. Meanwhile, a trough of low pressure will remain
along the south Oregon coast into Tue. This will keep north winds
along the central Oregon coastal waters gusting over 20 kt again
this afternoon and into the overnight.
Upper level low pressure will move over the region for the second
half of the week through next weekend. This will tend to weaken the
winds a bit. This system will bring an initial weak cold front
through
the waters early Wednesday, although at this time it appears winds
should remain below small craft criteria. However some localized
gusts 21-25 kt out of the northwest will be possible.
Wave heights generally remain 5 ft or less through Tuesday.
Computer model guidance shows seas getting up to around 8 or 9 ft
late Wednesday through the end of the week, then easing to 5 ft
or so by the weekend. /Bowen
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...Small Craft Advisory for winds until 5 AM PDT Wednesday for
Coastal Waters from Cascade Head OR to Florence OR out 60
nm.
&&
$$
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This discussion is for Northwest Oregon and Southwest Washington
from the Cascade crest to 60 nautical miles offshore. The area is
commonly referred to as the forecast area.
Area Forecast Discussion
National Weather Service Little Rock AR
249 PM CDT THU MAY 19 2016
.SHORT TERM...Today Through Saturday
Data from the water vapor channel continues to indicate the
progression of short wave energy...moving eastward over western
oklahoma and western north texas. Precipitation associated with
this feature is approaching from the west and southwest...per data
from local radars. Moisture transport to the region...ahead of
the short wave energy..is expected to be affected by the
convective complex now affecing southeast Texas. Greatest
coverage of rainfall overnight is expected in the 00z-05z
timeframe.
Some scattered...lingering light rain will be possible Friday
morning...otherwise dry conditions expected for the rest of this
period.
&&
.LONG TERM...Saturday Night Through Thursday
A shortwave ridge aloft will dominate the forecast area over the
weekend, and this ridge will break down on Monday as a southwesterly
flow reestablishes itself. Broad trof over the western US will
continue to kick out shortwaves to the east, which will result in
rain chances throughout the entire workweek.
At the surface high pressure will dominate this weekend, and this
will slide eastward bringing a return flow of warm and humid air
from the south. Toward the latter half of the forecast period the
models are forecasting a cold front to stall out across the northern
half of the forecast area. However, the models have been having
difficulty handling the position and timing of slow moving fronts
lately, and am not putting too much stock into the specifics of this
boundary just yet.
With the increasing southerly flow and anticipated shortwaves
passing across the area in the southwesterly flow aloft, I have kept
POPs in the forecast for almost all areas in the Monday thru
Thursday night time frame.
&&
.PRELIMINARY POINT TEMPS/POPS...
Batesville AR 55 74 55 76 / 50 40 10 10
Camden AR 59 78 60 83 / 70 40 10 10
Harrison AR 52 71 53 74 / 50 30 10 10
Hot Springs AR 58 76 59 80 / 60 30 10 10
Little Rock AR 58 76 61 80 / 60 40 10 10
Monticello AR 61 78 60 80 / 60 60 10 10
Mount Ida AR 56 76 56 80 / 60 20 10 10
Mountain Home AR 53 72 54 75 / 40 30 10 10
Newport AR 57 75 57 77 / 50 50 10 10
Pine Bluff AR 59 76 60 79 / 60 50 10 10
Russellville AR 57 75 57 79 / 60 30 10 10
Searcy AR 56 75 57 78 / 50 40 10 10
Stuttgart AR 60 75 61 79 / 60 50 10 10
&&
.LZK Watches/Warnings/Advisories...NONE.
&&
$$
Short Term...55 / Long Term...53
Area Forecast Discussion
National Weather Service Little Rock AR
1217 PM CDT THU MAY 19 2016
.AVIATION...
FORECASTS WILL REFLECT EXPECTED TIMING OF WEAK
CONVECTION...PASSING FROM WEST TO EAST BETWEEN 00Z AND 10Z. HIGH
END IFR CIGS EXPECTED TO DEVELOP AT MOST AREAS BETWEEN 08Z AND
12Z.
55
&&
.PREV DISCUSSION... /ISSUED /
AVIATION...
Widespread VFR conditions continue this morning but conditions are
expected to deteriorate with time as a storm system approaches from
the west. The onset of the precipitation will be delayed until later
this afternoon with conditions becoming mvfr. winds will generally
be light and from the east to northeast.
SHORT TERM...Thursday through Friday night.
Biggest change this morning versus the past several concerns the
speed of the next shortwave expected to impact the area. All short
term / high resolution models continue to slow down this feature
with precipitation now not expected to reach the western sections of
the CWA until mid to possibly late afternoon. Current runs of the
hrrr and wrf seem to have initialized very well and will follow
their lead this morning. Nam solution also looks good expect for
some feedback concerns it seems to be experiencing regarding
rainfall.
Latest analysis shows a frontal boundary stretched along the gulf
coast and upper trough over the desert southwest. Surface high
pressure over the upper Midwest will slowly pull away while trough
reaches the south central plains by the end of the day. Impulse in
advance of the main trough will interact with this boundary to
eventually produce showers and isolated thunderstorms. No severe
weather is expected.
Models continue to delay the onset of the precipitation until this
afternoon with rain expected tonight and into early Friday when the
impulse exits to the east. Heaviest rain amounts will be across the
south closer to the front but not expecting excessive rain amounts
at this point. Will hedge on the side of caution with having seen
this pattern before where gulf coast convection robs the moisture
that otherwise one would expect.
Upper ridge will build over the region in the wake of the impulse
with dry conditions expected to round out the period. Temperatures
will continue to run below below normal but a little bit warmer than
what has been seen recently.
LONG TERM...Saturday through Wednesday
An upper ridge will be over the center portion of the country to
begin the long term period with an upper low over the west coast and
an upper trough over the east. Arkansas will be under the ridge
through the weekend then the ridge moves east on Monday. Another
ridge builds into the southern plains Tuesday from the Gulf of
Mexico as the upper low moves to the Rockies...for Tuesday and
Wednesday.
The weekend is expected to be dry with high pressure dominating.
Moisture begins to return on Monday and thunderstorm chances
increase Monday night into Tuesday as a short wave moves through the
area. Models indicate another short wave to move through the area
Wednesday...so will continue pops for Wednesday. Below normal
temperatures are expected through Monday...but will be back to near
normal Tuesday and Wednesday.
&&
.LZK Watches/Warnings/Advisories...NONE.
&&
$$
Aviation...99
Area Forecast Discussion
National Weather Service Little Rock AR
305 AM CDT THU MAY 19 2016
SHORT TERM...Thursday through Friday night.
Biggest change this morning versus the past several concerns the
speed of the next shortwave expected to impact the area. All short
term / high resolution models continue to slow down this feature
with precipitation now not expected to reach the western sections of
the CWA until mid to possibly late afternoon. Current runs of the
hrrr and wrf seem to have initialized very well and will follow
their lead this morning. Nam solution also looks good expect for
some feedback concerns it seems to be experiencing regarding
rainfall.
Latest analysis shows a frontal boundary stretched along the gulf
coast and upper trough over the desert southwest. Surface high
pressure over the upper Midwest will slowly pull away while trough
reaches the south central plains by the end of the day. Impulse in
advance of the main trough will interact with this boundary to
eventually produce showers and isolated thunderstorms. No severe
weather is expected.
Models continue to delay the onset of the precipitation until this
afternoon with rain expected tonight and into early Friday when the
impulse exits to the east. Heaviest rain amounts will be across the
south closer to the front but not expecting excessive rain amounts
at this point. Will hedge on the side of caution with having seen
this pattern before where gulf coast convection robs the moisture
that otherwise one would expect.
Upper ridge will build over the region in the wake of the impulse
with dry conditions expected to round out the period. Temperatures
will continue to run below below normal but a little bit warmer than
what has been seen recently.
&&
.LONG TERM...Saturday through Wednesday
An upper ridge will be over the center portion of the country to
begin the long term period with an upper low over the west coast and
an upper trough over the east. Arkansas will be under the ridge
through the weekend then the ridge moves east on Monday. Another
ridge builds into the southern plains Tuesday from the Gulf of
Mexico as the upper low moves to the Rockies...for Tuesday and
Wednesday.
The weekend is expected to be dry with high pressure dominating.
Moisture begins to return on Monday and thunderstorm chances
increase Monday night into Tuesday as a short wave moves through the
area. Models indicate another short wave to move through the area
Wednesday...so will continue pops for Wednesday. Below normal
temperatures are expected through Monday...but will be back to near
normal Tuesday and Wednesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Batesville AR 73 56 74 55 / 10 60 40 10
Camden AR 73 60 78 59 / 50 80 40 10
Harrison AR 70 53 71 53 / 20 50 30 10
Hot Springs AR 70 59 75 59 / 50 60 30 10
Little Rock AR 74 60 75 60 / 30 70 40 10
Monticello AR 75 62 77 60 / 30 80 60 10
Mount Ida AR 70 56 75 56 / 50 50 20 10
Mountain Home AR 72 54 73 53 / 20 50 30 10
Newport AR 74 58 75 57 / 10 70 50 10
Pine Bluff AR 73 61 75 60 / 30 70 50 10
Russellville AR 73 57 76 57 / 30 50 30 10
Searcy AR 73 58 74 57 / 20 70 40 10
Stuttgart AR 73 61 75 60 / 20 70 50 10
&&
.LZK Watches/Warnings/Advisories...NONE.
&&
$$
Short Term...56 / Long Term...51
Area Forecast Discussion
National Weather Service Little Rock AR
653 PM CDT WED MAY 18 2016
.AVIATION...
Clouds have continued to scatter out within the past two hours
with VFR conditions being seen at all TAF sites except for KHOT.
Some precipitation will push into western Arkansas around
18z...and at this point have only included VCSH at KHOT and KADF.
Do believe the precipitation will hold off until after 00z for the
remainder of the TAF sites.
&&
.PREV DISCUSSION... /ISSUED /
SHORT TERM...Tonight through Friday night...
Shortwave over the Southwestern US will continue to move eastward
during the short term, eventually moving over the forecast area late
Friday. In the interim several minor impulses will likely be
ejected out ahead of the wave across Arkansas.
At the surface, the boundary to the south will move back to the
north and stall during the short term, and will set up a focal point
for rainfall with the shortwave approaching, with general rainfall
amounts likely maxing out in the 0.75 to 1.00 inch range. I have
highest POPs Thursday night thru Friday morning.
Long Term...Friday night through Tuesday...
Persistence troughing across the western third of the US will
make for a challenging forecast late in the extended periods.
Models are in good agreement in advertising a brief period of
ridging, both at the surface and aloft, for this weekend. So,
mostly clear skies with mild to warm days and cool nights expected
Friday night through Monday.
A return to southerly surface flow on Monday will allow for low
level moisture to surge back into the area. By late Monday, a weak
pacific cold front will be approaching from the west in association
with a very weak disturbance embedded in the southwest flow aloft.
This will bring, what appears to be a decent chance, for a round of
shower and thunderstorms Monday night and Tuesday. Rain chances are
likely to continue into Wed as well. At this point, the threat for
severe weather looks minimal.
Temperatures will generally remain at or below normal through the
period. Although as moisture returns early next week, min temps will
moderate quite a bit. Afternoon temps early next week will edge into
the lower to mid 80s but with noticably increased humidity levels.
&&
.LZK Watches/Warnings/Advisories...NONE.
&&
$$
Aviation...65
Area Forecast Discussion
National Weather Service Little Rock AR
225 PM CDT WED MAY 18 2016
.SHORT TERM...Tonight through Friday night...
Shortwave over the Southwestern US will continue to move eastward
during the short term, eventually moving over the forecast area late
Friday. In the interim several minor impulses will likely be
ejected out ahead of the wave across Arkansas.
At the surface, the boundary to the south will move back to the
north and stall during the short term, and will set up a focal point
for rainfall with the shortwave approaching, with general rainfall
amounts likely maxing out in the 0.75 to 1.00 inch range. I have
highest POPs Thursday night thru Friday morning.
&&
.Long Term...Friday night through Tuesday...
Persistence troughing across the western third of the US will
make for a challenging forecast late in the extended periods.
Models are in good agreement in advertising a brief period of
ridging, both at the surface and aloft, for this weekend. So,
mostly clear skies with mild to warm days and cool nights expected
Friday night through Monday.
A return to southerly surface flow on Monday will allow for low
level moisture to surge back into the area. By late Monday, a weak
pacific cold front will be approaching from the west in association
with a very weak disturbance embedded in the southwest flow aloft.
This will bring, what appears to be a decent chance, for a round of
shower and thunderstorms Monday night and Tuesday. Rain chances are
likely to continue into Wed as well. At this point, the threat for
severe weather looks minimal.
Temperatures will generally remain at or below normal through the
period. Although as moisture returns early next week, min temps will
moderate quite a bit. Afternoon temps early next week will edge into
the lower to mid 80s but with noticably increased humidity levels.
&&
.PRELIMINARY POINT TEMPS/POPS...
Batesville AR 51 72 55 73 / 10 20 60 40
Camden AR 56 72 59 77 / 20 60 80 50
Harrison AR 48 69 52 70 / 10 20 50 30
Hot Springs AR 55 69 58 74 / 20 50 70 40
Little Rock AR 56 73 59 74 / 10 40 80 40
Monticello AR 57 74 61 76 / 20 40 80 50
Mount Ida AR 53 69 55 74 / 20 50 70 30
Mountain Home AR 49 71 53 72 / 10 20 60 30
Newport AR 53 73 57 74 / 10 20 70 40
Pine Bluff AR 55 72 60 74 / 10 40 80 50
Russellville AR 54 72 56 75 / 10 40 60 30
Searcy AR 52 72 57 73 / 10 20 70 50
Stuttgart AR 56 72 60 74 / 10 30 80 50
&&
.LZK Watches/Warnings/Advisories...NONE.
&&
$$
Short Term...53 / Long Term...32
Area Forecast Discussion
National Weather Service Little Rock AR
853 AM CDT WED MAY 18 2016
.UPDATE...
Made a few tweaks to the POP and weather grids based on current
trends and HRRR model trends for precipitation today. For the
most part I upped precip chances across the south and introduced
some POPs in the central and northeast areas.
Going to take a look at temps here next and see if any updates are
needed. With significant cloud cover and cool morning temps I may
have to make some adjustments. 53
&&
.PREV DISCUSSION...
AVIATION...
Ifr conditions continue at this hour in the wake of a cold front
that moved through last evening. Conditions will gradually
become vfr with time but skies will never completely clear out.
Winds will be light and from the north to northeast. Lower clouds
will begin to spread back in at most terminals late in the period
as the next system approaches.
&&
SHORT TERM...Wednesday through Thursday night.
Latest surface analysis shows the cold front that moved through the
state Tuesday evening is now located over northern Louisiana. Upper
flow has turned to the north in its wake with surface high pressure
located over the upper Midwest. Considerably drier air has spread
over the state with dew point temperatures roughly 15 degrees lower
before the fropa.
A weak impulse moving through the upper flow may kick off a shower
or two this morning over the south but otherwise conditions will
be mainly dry through tonight.
Meanwhile...upper level low pressure which is clearly visible on
moisture channel imagery this morning, will morph into more of an
open wave configuration and start to head east tonight. Upper flow
will turn southwest with moisture on the increase once again. With
the aforementioned front remaining to the south of the state, an
overrunning pattern will develop, aided by an upper impulse kicking
out of the trough.
As a result...showers and thunderstorms are expected to develop over
the area Thursday and into Thursday night. Northerly flow today and
developing precipitation with extensive cloud cover Thursday will
keep temperatures below normal levels through the period.
LONG TERM...Friday through Tuesday
An upper trough will be over the plains to begin the long term
period with a weak ridge over the Rockies and strong upper low over
the west coast. By Saturday night, the ridge builds over the plains
and the respective troughs will be along the coasts. The upper ridge
will be over Arkansas Monday night but will move east Tuesday.
Low pressure moving along a warm front will bring a chance of
showers and thunderstorms Friday. Surface high pressure moves into
the area for the weekend for dry weather. Rain chances then return
Monday night through Tuesday as a short wave moves through the state.
Temperatures will generally be below normal through the period.
&&
.LZK Watches/Warnings/Advisories...NONE.
&&
$$