000
FXUS66 KOTX 230539
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1045 PM PDT Wed May 22 2013
.SYNOPSIS...
a cool and wet period awaits the Inland Northwest care of a cold
upper level low. Occasional showers are expected each day through
the end of the week with cooler than normal temperatures. snow
will also be possible over the mountains. Conditions could
moderate a bit by the weekend as the low moves out of the area
but it will be replaced by another cool low sometime early next week.
&&
.DISCUSSION...
Second update for this evening: A band of nearly stationary light
to locally moderate precipitation remains in place across
Boundary...northern Pend Oreille...and northern Stevens Counties.
Following some calls to the counties...there is very little issues
regarding flooding from the 1-3 inches of rainfall over the last 2
days. Consequently, we have allowed the flood advisory to run its
course and allowed the product to expire as this band will finally
begin to drift north this evening as a dry slot now into
southeastern WA punches northward.
There are still some nuisance showers that were tied to the
afternoon instability and some weak midlevel forcing that will be
around for the next few hours. The most organized activity is a
along a line extending from Omak to Coeur D Alene. A second
cluster near Walla Walla will drift north into southern Adams and
western Whitman Counties within the hour. Lastly, isolated showers
continue to blossom over the western Columbia Basin and drift west
into the East Slopes. Each of these features will be capable of
brief heavy downpours and B-B size hail but should gradually
dissipate with the loss of daytime heating.
The key word is "should"...given the -30C cold pool aloft and
perhaps another midlevel circulation (vort max)...it is not a high
confidence forecast that the region will showers will
cease...especially over the East Slopes and far western Basin
within the proximity of the parent upper-low and we will maintain
a slight chance to chance wording.
As for temperatures...this is a tough forecast to say the least.
Most locations are carrying dewpoints that would keep temperatures
slightly above freezing tonight but given the clearing moving in
from the southeast under the dry slot...it will be a battle during
radiational cooling between going below freezing and formation of
fog. Several isolated locations like Winchester, Davenport,
Republic, Deer Park, and Priest Lake should reach freezing
overnight but there is low confidence that this will be widespread
enough throughout the zone to include in the freeze warning.
It still looks possible for the ID/WA Palouse so will maintain the
warning and will include the valleys of IDZ004 (Central Panhandle
Mtns) and Camas Prairie which received much less precipitation
throughout the day and will experience a great deal of clearing
and light winds overnight and have the best shot for a hard freeze
(25-29F). Locations like Bonners Ferry which fell to 32F under
moderate snow today have rebounded back around 36F and should
quickly fog in tonight as the precipitation ends. /sb
&&
.AVIATION...
06Z TAFS: An upper level low pressure area centered in the vicinity
of the aviation area will keep the threat for -shra vcnty KEAT and
KMWH through much of the night and Thur morning. Aftn heating will
promote light but widely sct -shra across the region for just about
any location. Some showers may produce MVFR ceilings at times.
Additionally some late night and early morning fog could produce
brief IFR/LIFR visibilities with KSFF/KLWS carrying the highest
threat for fog formation. Patchy frost will be possible near KPUW
and KDEW. All terminals are expected to receive a break from pcpn
and VFR skies aft 02z. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 36 60 41 60 42 64 / 30 20 20 40 30 30
Coeur d`Alene 35 59 37 60 40 64 / 70 20 20 50 40 30
Pullman 32 59 37 57 40 64 / 20 20 20 50 20 30
Lewiston 36 66 44 64 45 71 / 20 20 10 50 20 30
Colville 35 63 37 68 41 69 / 70 30 30 50 50 40
Sandpoint 34 58 35 62 39 64 / 80 30 20 60 50 40
Kellogg 29 55 37 56 41 61 / 70 30 30 60 50 40
Moses Lake 39 66 41 69 45 72 / 20 20 20 30 20 10
Wenatchee 41 63 44 66 47 69 / 60 40 30 40 20 20
Omak 35 65 37 68 42 69 / 50 30 30 40 30 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Freeze Warning from 2 AM to 7 AM PDT Thursday for Central
Panhandle Mountains-Idaho Palouse-Lewis and Southern Nez
Perce Counties.
WA...Freeze Warning from 2 AM to 7 AM PDT Thursday for Washington
Palouse.
&&
$$
000
FXUS66 KOTX 230459
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
959 PM PDT Wed May 22 2013
.SYNOPSIS...
a cool and wet period awaits the Inland Northwest care of a cold
upper level low. Occasional showers are expected each day through
the end of the week with cooler than normal temperatures. snow
will also be possible over the mountains. Conditions could
moderate a bit by the weekend as the low moves out of the area
but it will be replaced by another cool low sometime early next week.
&&
.DISCUSSION...
Second update for this evening: A band of nearly stationary light
to locally moderate precipitation remains in place across
Boundary...northern Pend Oreille...and northern Stevens Counties.
Following some calls to the counties...there is very little issues
regarding flooding from the 1-3 inches of rainfall over the last 2
days. Consequently, we have allowed the flood advisory to run its
course and allowed the product to expire as this band will finally
begin to drift north this evening as a dry slot now into
southeastern WA punches northward.
There are still some nuisance showers that were tied to the
afternoon instability and some weak midlevel forcing that will be
around for the next few hours. The most organized activity is a
along a line extending from Omak to Coeur D Alene. A second
cluster near Walla Walla will drift north into southern Adams and
western Whitman Counties within the hour. Lastly, isolated showers
continue to blossom over the western Columbia Basin and drift west
into the East Slopes. Each of these features will be capable of
brief heavy downpours and B-B size hail but should gradually
dissipate with the loss of daytime heating.
The key word is "should"...given the -30C cold pool aloft and
perhaps another midlevel circulation (vort max)...it is not a high
confidence forecast that the region will showers will
cease...especially over the East Slopes and far western Basin
within the proximity of the parent upper-low and we will maintain
a slight chance to chance wording.
As for temperatures...this is a tough forecast to say the least.
Most locations are carrying dewpoints that would keep temperatures
slightly above freezing tonight but given the clearing moving in
from the southeast under the dry slot...it will be a battle during
radiational cooling between going below freezing and formation of
fog. Several isolated locations like Winchester, Davenport,
Republic, Deer Park, and Priest Lake should reach freezing
overnight but there is low confidence that this will be widespread
enough throughout the zone to include in the freeze warning.
It still looks possible for the ID/WA Palouse so will maintain the
warning and will include the valleys of IDZ004 (Central Panhandle
Mtns) and Camas Prairie which received much less precipitation
throughout the day and will experience a great deal of clearing
and light winds overnight and have the best shot for a hard freeze
(25-29F). Locations like Bonners Ferry which fell to 32F under
moderate snow today have rebounded back around 36F and should
quickly fog in tonight as the precipitation ends. /sb
&&
.AVIATION...
00Z TAFS: An upper level low pressure area centered in the vicinity
of the aviation area allows for a cluttered forecast of primarily
showers at various times, either surface based or the elevated
forced type in the forecast for most of the time interval through
00Z Friday. These showers may produce MVFR ceilings at times.
Additionally some late night and early morning fog near rivers and
northern valleys could produce brief MVFR visibilities along with
some frost as temperatures drop below freezing for a brief spell
near KPUW, KDEW...and other more favorable aviation locations.
Additionally a very small potential for thunder exists near
Cascades and vicinity KLWS and portions of North Idaho Panhandle.
/Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 36 60 41 60 42 64 / 30 20 20 40 30 30
Coeur d`Alene 35 59 37 60 40 64 / 70 20 20 50 40 30
Pullman 32 59 37 57 40 64 / 20 20 20 50 20 30
Lewiston 36 66 44 64 45 71 / 20 20 10 50 20 30
Colville 35 63 37 68 41 69 / 70 30 30 50 50 40
Sandpoint 34 58 35 62 39 64 / 80 30 20 60 50 40
Kellogg 29 55 37 56 41 61 / 70 30 30 60 50 40
Moses Lake 39 66 41 69 45 72 / 20 20 20 30 20 10
Wenatchee 41 63 44 66 47 69 / 60 40 30 40 20 20
Omak 35 65 37 68 42 69 / 50 30 30 40 30 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Freeze Warning from 2 AM to 7 AM PDT Thursday for Central
Panhandle Mountains-Idaho Palouse-Lewis and Southern Nez
Perce Counties.
WA...Freeze Warning from 2 AM to 7 AM PDT Thursday for Washington
Palouse.
&&
$$
000
FXUS66 KOTX 230021
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
521 PM PDT Wed May 22 2013
.SYNOPSIS...
a cool and wet period awaits the Inland Northwest care of a cold
upper level low. Occasional showers are expected each day through
the end of the week with cooler than normal temperatures. snow
will also be possible over the mountains. Conditions could
moderate a bit by the weekend as the low moves out of the area
but it will be replaced by another cool low sometime early next week.
&&
.DISCUSSION...
Evening update: We have lowered snow levels and added some light
snow accumulations for the far northern portions of the Idaho
Panhandle...mostly over Boundary County where moderate to heavy
precipitation continues to fall and is driving down snow levels to
elevations as low as 1800 ft. A spotter from Moyie at an elevation
of 2300` has reported one inch of snow with this activity. Most
CAMS from the area do not show accumulations on roadways so will
hold off on any winter weather highlights.
We have also increased pops and added isolated thunderstorms
across southeastern WA and lower portions of the Columbia Basin.
Breaks in the cloud cover coupled with the -30C cold pool under
the upper-low has resulted in widely scattered showers and a few
thunderstorms. At this time the main t-storm activity was over the
Pomeroy area and this may need to be expanded to the west and
north and will see how trends are the next hour before making
additional changes. /sb
&&
.AVIATION...
00Z TAFS: An upper level low pressure area centered in the vicinity
of the aviation area allows for a cluttered forecast of primarily
showers at various times, either surface based or the elevated
forced type in the forecast for most of the time interval through
00Z Friday. These showers may produce MVFR ceilings at times.
Additionally some late night and early morning fog near rivers and
northern valleys could produce brief MVFR visibilities along with
some frost as temperatures drop below freezing for a brief spell
near KPUW, KDEW...and other more favorable aviation locations.
Additionally a very small potential for thunder exists near
Cascades and vicinity KLWS and portions of North Idaho Panhandle.
/Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 36 60 41 60 42 64 / 20 20 20 40 30 30
Coeur d`Alene 35 59 37 60 40 64 / 20 20 20 40 40 30
Pullman 32 59 37 57 40 64 / 30 20 20 40 20 30
Lewiston 38 66 44 64 45 71 / 40 20 10 40 20 30
Colville 35 63 37 68 41 69 / 70 30 30 50 40 40
Sandpoint 34 58 35 62 39 64 / 80 30 20 50 50 40
Kellogg 34 55 37 56 41 61 / 40 30 30 50 50 40
Moses Lake 39 66 41 69 45 72 / 40 20 20 30 20 10
Wenatchee 41 63 44 66 47 69 / 60 40 30 30 20 20
Omak 35 65 37 68 42 69 / 60 30 30 40 30 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Freeze Warning from 2 AM to 7 AM PDT Thursday for Idaho Palouse.
WA...Freeze Warning from 2 AM to 7 AM PDT Thursday for Washington
Palouse.
&&
$$
000
FXUS66 KOTX 222333
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
426 PM PDT Wed May 22 2013
.SYNOPSIS...
a cool and wet period awaits the Inland Northwest care of a cold
upper level low. Occasional showers are expected each day through
the end of the week with cooler than normal temperatures. snow
will also be possible over the mountains. Conditions could
moderate a bit by the weekend as the low moves out of the area
but it will be replaced by another cool low sometime early next week.
&&
.DISCUSSION...
Tonight...Large closed low centered near Yakima this evening will
move northwest towards Seattle overnight. Models show the theta e
ridge axis which has brought heavy rain over the North Idaho
Panhandle and north Pend Oreille county shifting east into western
Montana this evening. A flood advisory remains in effect through
this evening for this area. The closed low position tonight will
result in south-southeast flow over Central and Eastern
Washington and North Idaho with showers rotating around the low.
LAPS data from this afternoon also has CAPE values of around 200
J/KG from Wenatchee through Hanford and the Blue Mountains which
could spark a stray thunderstorm. All models show a wedge of drier
air coming up from the south tonight which should dry most areas
out once evening showers die off with the loss of daytime heating.
However closer to the Cascades showers may persist overnight given
close proximity to low center.
With the drier air skies will have an opportunity to become mostly
clear or partly cloudy for Eastern Washington overnight. This
combined with a cool start with afternoon temperatures only in the
mid 40s over most areas will result in a cool night. Freezing
temperatures are expected for most locations on the Palouse and a
freeze warning has been issued. A tougher call for the northern
valleys where abundant boundary layer moisture may allow for more
fog or stratus to develop which would keep lows near or slightly
below freezing. With lower confidence opted to not include the
northern valleys, but colder spots like Republic and Deer Park
will have a good chance of reaching 30-32 degrees F. JW
.Thursday through Saturday...Cold upper level low will remain
the dominant feature through this period. Model solutions are
exhibiting very good agreement with the movement of the low and
the placement of the associated deformation band of precipitation.
The current deformation band which is responsible for the
widespread band of precipitation extending from NE Washington into
the central Panhandle...is expected to track E-NE overnight and
and move into NW Montana by late-morning or early afternoon. Drier
and more stable air is expected to move in its wake which will
likely bring a brief drying trend across much of the Inland NW at
least through the morning. The atmosphere is expected to
destabilize in the afternoon due to diurnal heating...and
scattered showers could develop over the eastern half of the
forecast area. Farther west...the presence of the low near the
mouth of the Columbia will result in weak upslope easterly flow
into the Cascades and keep more persistent shower activity fixed
over that region. Temperatures should moderate quite a bit
compared to today as a bit more sunshine is expected with the core
of the upper level low shifting the coldest air to our west.
By Thursday night into early Friday the low is expected to wobble
into central Oregon before heading north-northeast. This should
result in drying conditions for most locations. By Friday
afternoon...the models continue to exhibit great consistency by
showing the upper level low will wandering into NE Oregon with the
atmosphere over the Inland NW exhibiting a rapid destabilization.
Showers will likely become plentiful as model CAPE values climb
into the 250-500 j/kg range with no convective CAP. Given the
southerly mid-level flow...the most abundant activity will cluster
along the northern forecast zones adjacent to the Canadian border.
Thunderstorms look like a possibility given the stability
parameters...however the lack of strong ascent aloft the coverage
will be underwhelming.
For Saturday...the low will meander back west of the Cascades...
with the best chances of precipitation focusing over the northern
and western portions of the forecast area...near the Canadian
border and Cascades. Once again the instability parameters suggest
a small chance of thunderstorms...however most of the upper level
ascent will remain focused west of the Cascades. Temperatures will
continue to moderate through the period with highs climbing into
the mid 60s to lower 70s for most valley locations. fx
Saturday night through Wednesday...Long-wave trof continues to
influence the Western United States through this time
interval...therefore this interval remains marked with below
normal temperatures...lower than usual snow levels at times...and
moderate pops and amounts of precipitation at times. The flow
does become westerly enough and void of disturbances to allow for
some intervals of drying between shortwave passages but as far as
shortwave features traversing through there are just enough timing
differences in passing each one through (and there appears to be
about four or more) that there isn`t enough confidence to modify
any timing of each feature in the forecast...so the end result
syntax wise is a forecast cluttered with generally chance pop
wording. /Pelatti
&&
.AVIATION...
00Z TAFS: An upper level low pressure area centered in the vicinity
of the aviation area allows for a cluttered forecast of primarily
showers at various times, either surface based or the elevated
forced type in the forecast for most of the time interval through
00Z Friday. These showers may produce MVFR ceilings at times.
Additionally some late night and early morning fog near rivers and
northern valleys could produce brief MVFR visibilities along with
some frost as temperatures drop below freezing for a brief spell
near KPUW, KDEW...and other more favorable aviation locations.
Additionally a very small potential for thunder exists near
Cascades and vicinity KLWS and portions of North Idaho Panhandle.
/Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 36 60 42 60 42 64 / 20 20 20 40 30 30
Coeur d`Alene 35 59 39 60 40 64 / 20 20 20 40 40 30
Pullman 32 59 39 57 40 64 / 20 20 20 40 20 30
Lewiston 38 66 45 64 45 71 / 20 20 10 40 20 30
Colville 35 63 39 68 41 69 / 70 30 30 50 40 40
Sandpoint 35 58 38 62 39 64 / 80 30 20 50 50 40
Kellogg 34 55 40 56 41 61 / 40 30 30 50 50 40
Moses Lake 39 66 43 69 45 72 / 20 20 20 30 20 10
Wenatchee 41 63 44 66 47 69 / 60 40 30 30 20 20
Omak 35 65 39 68 42 69 / 50 30 30 40 30 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Freeze Warning from 2 AM to 7 AM PDT Thursday for Idaho Palouse.
WA...Freeze Warning from 2 AM to 7 AM PDT Thursday for Washington
Palouse.
&&
$$
000
FXUS66 KOTX 222153
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
253 PM PDT Wed May 22 2013
.SYNOPSIS...
a cool and wet period awaits the Inland Northwest care of a cold
upper level low. Occasional showers are expected each day through
the end of the week with cooler than normal temperatures. snow
will also be possible over the mountains. Conditions could
moderate a bit by the weekend as the low moves out of the area
but it will be replaced by another cool low sometime early next week.
&&
.DISCUSSION...
Tonight...Large closed low centered near Yakima this evening will
move northwest towards Seattle overnight. Models show the theta e
ridge axis which has brought heavy rain over the North Idaho
Panhandle and north Pend Oreille county shifting east into western
Montana this evening. A flood advisory remains in effect through
this evening for this area. The closed low position tonight will
result in south-southeast flow over Central and Eastern
Washington and North Idaho with showers rotating around the low.
LAPS data from this afternoon also has CAPE values of around 200
J/KG from Wenatchee through Hanford and the Blue Mountains which
could spark a stray thunderstorm. All models show a wedge of drier
air coming up from the south tonight which should dry most areas
out once evening showers die off with the loss of daytime heating.
However closer to the Cascades showers may persist overnight given
close proximity to low center.
With the drier air skies will have an opportunity to become mostly
clear or partly cloudy for Eastern Washington overnight. This
combined with a cool start with afternoon temperatures only in the
mid 40s over most areas will result in a cool night. Freezing
temperatures are expected for most locations on the Palouse and a
freeze warning has been issued. A tougher call for the northern
valleys where abundant boundary layer moisture may allow for more
fog or stratus to develop which would keep lows near or slightly
below freezing. With lower confidence opted to not include the
northern valleys, but colder spots like Republic and Deer Park
will have a good chance of reaching 30-32 degrees F. JW
.Thursday through Saturday...Cold upper level low will remain
the dominant feature through this period. Model solutions are
exhibiting very good agreement with the movement of the low and
the placement of the associated deformation band of precipitation.
The current deformation band which is responsible for the
widespread band of precipitation extending from NE Washington into
the central Panhandle...is expected to track E-NE overnight and
and move into NW Montana by late-morning or early afternoon. Drier
and more stable air is expected to move in its wake which will
likely bring a brief drying trend across much of the Inland NW at
least through the morning. The atmosphere is expected to
destabilize in the afternoon due to diurnal heating...and
scattered showers could develop over the eastern half of the
forecast area. Farther west...the presence of the low near the
mouth of the Columbia will result in weak upslope easterly flow
into the Cascades and keep more persistent shower activity fixed
over that region. Temperatures should moderate quite a bit
compared to today as a bit more sunshine is expected with the core
of the upper level low shifting the coldest air to our west.
By Thursday night into early Friday the low is expected to wobble
into central Oregon before heading north-northeast. This should
result in drying conditions for most locations. By Friday
afternoon...the models continue to exhibit great consistency by
showing the upper level low will wandering into NE Oregon with the
atmosphere over the Inland NW exhibiting a rapid destabilization.
Showers will likely become plentiful as model CAPE values climb
into the 250-500 j/kg range with no convective CAP. Given the
southerly mid-level flow...the most abundant activity will cluster
along the northern forecast zones adjacent to the Canadian border.
Thunderstorms look like a possibility given the stability
parameters...however the lack of strong ascent aloft the coverage
will be underwhelming.
For Saturday...the low will meander back west of the Cascades...
with the best chances of precipitation focusing over the northern
and western portions of the forecast area...near the Canadian
border and Cascades. Once again the instability parameters suggest
a small chance of thunderstorms...however most of the upper level
ascent will remain focused west of the Cascades. Temperatures will
continue to moderate through the period with highs climbing into
the mid 60s to lower 70s for most valley locations. fx
Saturday night through Wednesday...Long-wave trof continues to
influence the Western United States through this time
interval...therefore this interval remains marked with below
normal temperatures...lower than usual snow levels at times...and
moderate pops and amounts of precipitation at times. The flow
does become westerly enough and void of disturbances to allow for
some intervals of drying between shortwave passages but as far as
shortwave features traversing through there are just enough timing
differences in passing each one through (and there appears to be
about four or more) that there isn`t enough confidence to modify
any timing of each feature in the forecast...so the end result
syntax wise is a forecast cluttered with generally chance pop
wording. /Pelatti
&&
.AVIATION...
18Z TAFS: An upper low pivoting across the Columbia Basin and then
toward western Washington over the next 24 hours will bring bands
of rain to central/eastern WA and northern ID. Coverage is
expected to be highest through 20-22z over the eastern TAF sites,
before turning showery in the afternoon. The western TAF sites
will also see a modest chance of showers, with the easterly
upslope flow providing the most prolonged threat near KEAT.
A very moist boundary layer will lead to continued MVFR CIGS this
morning with gradual improvement through the day. Confidence is less
around the western TAF sites but the more persistent upslope flow
developing into KEAT may produce lower cigs for a longer period.
Isolated afternoon thunderstorm are possible near the Cascades and
central ID panhandle mtns, generally away from TAFs. JW
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 36 60 42 60 42 64 / 20 20 20 40 30 30
Coeur d`Alene 35 59 39 60 40 64 / 20 20 20 40 40 30
Pullman 32 59 39 57 40 64 / 20 20 20 40 20 30
Lewiston 38 66 45 64 45 71 / 20 20 10 40 20 30
Colville 35 63 39 68 41 69 / 70 30 30 50 40 40
Sandpoint 35 58 38 62 39 64 / 80 30 20 50 50 40
Kellogg 34 55 40 56 41 61 / 40 30 30 50 50 40
Moses Lake 39 66 43 69 45 72 / 20 20 20 30 20 10
Wenatchee 41 63 44 66 47 69 / 60 40 30 30 20 20
Omak 35 65 39 68 42 69 / 50 30 30 40 30 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Freeze Warning from 2 AM to 7 AM PDT Thursday for Idaho Palouse.
WA...Freeze Warning from 2 AM to 7 AM PDT Thursday for Washington
Palouse.
&&
$$
000
FXUS66 KOTX 221801
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1101 AM PDT Wed May 22 2013
.SYNOPSIS...
The Inland Northwest will remain under a broad trough through at
least the middle of next week, with disturbances riding in from
the Pacific. This set up means several opportunities for
precipitation. Temperatures are expected to remain cooler than
normal through the end of this week, before some moderation.
&&
.DISCUSSION...
Rain wrapping around a large closed low centered near Hanford as
of 1030 am will continue to slowly migrate north today. A strong
wave rotating around this low will track from southeast Washington
and the Lewiston area late this morning into Northeast Washington
and the Idaho Panhandle early this afternoon...exiting the area
into southern British Columbia this evening. A band of steady rain
will move through these areas as this wave passes through. A theta
e ridge axis extending from near Lookout Pass to Bonners Ferry
will provide an axis of heavier rainfall with additional rainfall
totals of a half to three quarters of an inch expected. This is on
top of 1-1.5 inches of rain that has already fallen such that some
places may receive rainfall totals as high as 2-2.25 inches. With
this in mind and with a report of ponding of water on roads in
Boundary county opted to upgrade the flood watches to advisories.
Also, with persistent cloud cover today high temperatures were
lowered for most areas. JW
&&
.AVIATION...
18Z TAFS: An upper low pivoting across the Columbia Basin and then
toward western Washington over the next 24 hours will bring bands
of rain to central/eastern WA and northern ID. Coverage is
expected to be highest through 20-22z over the eastern TAF sites,
before turning showery in the afternoon. The western TAF sites
will also see a modest chance of showers, with the easterly
upslope flow providing the most prolonged threat near KEAT.
A very moist boundary layer will lead to continued MVFR CIGS this
morning with gradual improvement through the day. Confidence is less
around the western TAF sites but the more persistent upslope flow
developing into KEAT may produce lower cigs for a longer period.
Isolated afternoon thunderstorm are possible near the Cascades and
central ID panhandle mtns, generally away from TAFs. JW
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 48 36 61 44 62 41 / 90 20 20 10 50 40
Coeur d`Alene 45 35 61 41 61 40 / 80 20 20 20 50 60
Pullman 48 34 61 40 58 40 / 90 20 20 20 60 50
Lewiston 56 39 67 46 65 46 / 90 20 20 20 60 50
Colville 48 36 66 41 69 40 / 90 60 30 20 40 50
Sandpoint 43 35 60 40 62 39 / 90 70 30 20 50 60
Kellogg 43 34 56 42 58 41 / 80 40 30 40 60 60
Moses Lake 55 40 67 45 70 44 / 50 20 30 20 30 20
Wenatchee 52 40 65 45 66 46 / 70 60 40 20 30 20
Omak 50 36 66 41 69 42 / 80 50 40 20 30 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 221558
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
858 AM PDT Wed May 22 2013
.SYNOPSIS...
The Inland Northwest will remain under a broad trough through at
least the middle of next week, with disturbances riding in from
the Pacific. This set up means several opportunities for
precipitation. Temperatures are expected to remain cooler than
normal through the end of this week, before some moderation.
&&
.DISCUSSION...
A large closed low near the Tri Cities will continue to produce
wrap around precipitation in the form of rain and mountain snow
today. This morning the heaviest rain will be focused along a
theta e ridge axis over far North Idaho...and in the Wenatchee
area given closest proximity to closed low with low level upslope
flow enhancing precip. Web cameras at Blewett and Stevens Pass
show this precipitation falling as snow this morning but with
roadways wet. This low is expected to migrate north slowly today
with the axis of more persistent rainfall moving north of the
Columbia Basin in the afternoon. However under the cold pool of
-30C at 500mb showers and isolated thunderstorms will develop
behind the main band of stratiform rain around Wenatchee and Moses
Lake. The forecast has been updated to increase precipitation
chances and rainfall amounts for today especially the Okanogan
Valley. Will likely need to evaluate high temperatures today as
forecast values may be slightly too high due to persistent cloud
cover especially near the Cascades, Spokane/Coeur D`Alene area,
and northern valleys. JW
&&
.AVIATION...
12Z TAFS: An upper low pivoting across the Columbia Basin and then
toward western Washington over the next 24 hours will bring bands
of rain to central/eastern WA and northern ID. Coverage is
expected to be best this morning and early afternoon over the
eastern TAF sites, before turning showery in the afternoon. Some
light snow may be mixed in during the morning. The western TAF
sites will also see a modest chance of showers, with the easterly
upslope flow providing the most prolonged threat near KEAT.
Confidence is low with regard to the precise ceilings, but look
for IFR/MVFR cigs over the eastern TAFs much of the morning with
improvement by the afternoon/evening. Confidence is less around
the western TAF sites but the more persistent upslope flow
developing into KEAT may produce lower cigs for a longer period.
Isolated afternoon thunderstorm are possible near the Cascades and
central ID panhandle mtns, generally away from TAFs. /J. Cote`
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 50 36 61 44 62 41 / 90 20 20 10 50 40
Coeur d`Alene 48 35 61 41 61 40 / 90 20 20 20 50 60
Pullman 50 34 61 40 58 40 / 90 20 20 20 60 50
Lewiston 58 39 67 46 65 46 / 90 20 20 20 60 50
Colville 54 36 66 41 69 40 / 100 60 30 20 40 50
Sandpoint 49 35 60 40 62 39 / 100 70 30 20 50 60
Kellogg 46 34 56 42 58 41 / 90 40 30 40 60 60
Moses Lake 59 40 67 45 70 44 / 50 20 30 20 30 20
Wenatchee 55 40 65 45 66 46 / 100 60 40 20 30 20
Omak 56 36 66 41 69 42 / 100 50 40 20 30 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Flood Watch through this evening for Northern Panhandle.
WA...Flood Watch through this evening for Northeast Mountains.
&&
$$
000
FXUS66 KOTX 221155
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
455 AM PDT Wed May 22 2013
.SYNOPSIS...
The Inland Northwest will remain under a broad trough through at
least the middle of next week, with disturbances riding in from
the Pacific. This set up means several opportunities for
precipitation. Temperatures are expected to remain cooler than
normal through the end of this week, before some moderation.
&&
.DISCUSSION...
Today and tonight: An upper low will continue take hold of the
West with cooler than normal and occasionally wet conditions.
Early this morning the center of low was situated near Redmond,
Oregon. All guidance tracks it into the Columbia Basin by midday,
before its tracks northwest toward the Puget Sound tonight.
Meanwhile at the surface a deformation axis/trough stretched from
the ID/MT border to northeast WA is projected to edge north and
east. For today these two features will provide a high threat of
showers across the central Cascades, portions of the Wenatchee
through Moses Lake zones, and the central and northern Idaho
Panhandle and northeast Washington mountain.
A flood watch continues for parts of northeast Washington and the
northern Panhandle through this evening (06Z Thursday). The region
received some moderate rainfall amounts Tuesday. With
precipitation continuing to train across this region this morning
and more expected through the day, this will make the region
susceptible to flooding. This is especially in the hillier/steep
terrain, low spots and near smaller streams/creeks.
Elsewhere models suggest a migratory precipitation threat. As the
upper low pivots north showers are expected to expand, first over
the east third and north-central WA this morning and second toward
midday/early afternoon into the Okanogan Valley, Waterville Plateau
and northern Cascades. By tonight the low migrates into the
Cascades and eventually western Washington and the deformation
axis near the Panhandle edges northeast, while drier air comes in
from the southeast. The easterly flow will continue to provide
high precipitation chances into the Cascades and across the
northern mountains, but the threat will begin to wane as the night
progresses. The shower threat elsewhere will be dwindling as drier
air comes in.
Some instability around the center of the low, indicated by High
Level Total Totals around 30-38C and low-grade CAPE around 100-150
J/kg, will provide at least an isolated thunderstorm threat near
the Cascades through the Upper Columbia Basin, as well as in the
vicinity of the Blue Mountains.
Snow levels around the upper low are expected to be near the
3000-4000 foot mark much of the period. Snow levels elsewhere
around 5000-7000 feet (highest toward the northern Panhandle) are
expected to lower to between 4000-5000 feet through the day. Thus
some snow or at least a rain/snow mix is likely to be seen around
the Blues, the Camas Prairie and mountain passes. There is the
potential for some snow even around the higher Palouse, including
the Pullman area, this morning.
Temperatures are expected to be held much below normal under the
cool core of the upper low. This means many areas struggling to
get into the 50s today. As for overnight lows tonight into
Thursday morning, we will have to monitor reading for potential
freezing warnings. Possible locations include the Okanogan
Highlands through the northern Panhandle, as well as the Palouse.
/J. Cote`
Thursday through Tuesday...Model agreement is quite good through
Friday...with some deterioration in detail commonality after
Friday but still display reasonable agreement regarding the over
all flow regime over and near the forecast area.
Thursday through Friday the upper level closed low is firmly
planted over the forecast area. The deformation band of persistent
and frequent showers currently entering the region will be off to
the north over southern BC and Alberta by Thursday morning...but
the forecast area will be under the direct influence of the low
center cold pool aloft with minor vorticity spokes available to
gin up showers in this weakly unstable and moist air mass. This
argues for a cool and showery regime with plenty of clouds and the
possibility of some fairly weak and isolated thunderstorms.
Impossible to nail down these sub-synoptic inter-trough
disturbances at this time...but suffice it to say just about
anywhere in the forecast area will be at risk for a shower or two
each day with the best chance over the mountains ringing the basin.
The holiday weekend harbors no better news for outdoor
enthusiasts. The good news is that the stubborn upper low will
weaken and become less coherent...but the bad news is a general
troffy pattern will remain over the region through the weekend.
Both the latest GFS and ECMWF place the axis of this opening
system/trough off the coast...which implies warmer temperatures in
a pre-trough southwest flow regime. However the area will remain
under cyclonic difluent flow aloft with likely a few sub-synoptic
disturbances rounding this flow Saturday through Monday. This
overall pattern does not suggest a particularly wet period...but
the risk of showers...particularly over the northern and eastern
mountains will present itself each day. Both models hint that the
highest risk of showers associated with a stronger disturbance
will be on Sunday and focused over the southeast and Idaho
Panhandle.
Tuesday the flow becomes a bit more progressive...but also brings
the threat of a stronger wave and surface occlusion to enhance
chances of rain once again.
Overall...there is high confidence of a distinctly unsettled and
occasionally showery regime right through the next week with low
confidence in timing any periods of heightened shower activity.
Temperatures will start out below normal Thursday and gradually
achieve seasonably normal values this weekend. /Fugazzi
&&
.AVIATION...
12Z TAFS: An upper low pivoting across the Columbia Basin and then
toward western Washington over the next 24 hours will bring bands
of rain to central/eastern WA and northern ID. Coverage is
expected to be best this morning and early afternoon over the
eastern TAF sites, before turning showery in the afternoon. Some
light snow may be mixed in during the morning. The western TAF
sites will also see a modest chance of showers, with the easterly
upslope flow providing the most prolonged threat near KEAT.
Confidence is low with regard to the precise ceilings, but look
for IFR/MVFR cigs over the eastern TAFs much of the morning with
improvement by the afternoon/evening. Confidence is less around
the western TAF sites but the more persistent upslope flow
developing into KEAT may produce lower cigs for a longer period.
Isolated afternoon thunderstorm are possible near the Cascades and
central ID panhandle mtns, generally away from TAFs. /J. Cote`
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 50 36 61 44 62 41 / 80 20 20 10 50 40
Coeur d`Alene 48 35 61 41 61 40 / 90 20 20 20 50 60
Pullman 50 34 61 40 58 40 / 70 20 20 20 60 50
Lewiston 58 39 67 46 65 46 / 50 20 20 20 60 50
Colville 54 36 66 41 69 40 / 90 60 30 20 40 50
Sandpoint 49 35 60 40 62 39 / 100 70 30 20 50 60
Kellogg 46 34 56 42 58 41 / 90 40 30 40 60 60
Moses Lake 59 40 67 45 70 44 / 50 20 30 20 30 20
Wenatchee 55 40 65 45 66 46 / 60 40 40 20 30 20
Omak 56 36 66 41 69 42 / 70 50 40 20 30 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Flood Watch through this evening for Northern Panhandle.
WA...Flood Watch through this evening for Northeast Mountains.
&&
$$
000
FXUS66 KOTX 220910
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
210 AM PDT Wed May 22 2013
.SYNOPSIS...
The Inland Northwest will remain under a broad trough through at
least the middle of next week, with disturbances riding in from
the Pacific. This set up means several opportunities for
precipitation. Temperatures are expected to remain cooler than
normal through the end of this week, before some moderation.
&&
.DISCUSSION...
Today and tonight: An upper low will continue take hold of the
West with cooler than normal and occasionally wet conditions.
Early this morning the center of low was situated near Redmond,
Oregon. All guidance tracks it into the Columbia Basin by midday,
before its tracks northwest toward the Puget Sound tonight.
Meanwhile at the surface a deformation axis/trough stretched from
the ID/MT border to northeast WA is projected to edge north and
east. For today these two features will provide a high threat of
showers across the central Cascades, portions of the Wenatchee
through Moses Lake zones, and the central and northern Idaho
Panhandle and northeast Washington mountain.
A flood watch continues for parts of northeast Washington and the
northern Panhandle through this evening (06Z Thursday). The region
received some moderate rainfall amounts Tuesday. With
precipitation continuing to train across this region this morning
and more expected through the day, this will make the region
susceptible to flooding. This is especially in the hillier/steep
terrain, low spots and near smaller streams/creeks.
Elsewhere models suggest a migratory precipitation threat. As the
upper low pivots north showers are expected to expand, first over
the east third and north-central WA this morning and second toward
midday/early afternoon into the Okanogan Valley, Waterville Plateau
and northern Cascades. By tonight the low migrates into the
Cascades and eventually western Washington and the deformation
axis near the Panhandle edges northeast, while drier air comes in
from the southeast. The easterly flow will continue to provide
high precipitation chances into the Cascades and across the
northern mountains, but the threat will begin to wane as the night
progresses. The shower threat elsewhere will be dwindling as drier
air comes in.
Some instability around the center of the low, indicated by High
Level Total Totals around 30-38C and low-grade CAPE around 100-150
J/kg, will provide at least an isolated thunderstorm threat near
the Cascades through the Upper Columbia Basin, as well as in the
vicinity of the Blue Mountains.
Snow levels around the upper low are expected to be near the
3000-4000 foot mark much of the period. Snow levels elsewhere
around 5000-7000 feet (highest toward the northern Panhandle) are
expected to lower to between 4000-5000 feet through the day. Thus
some snow or at least a rain/snow mix is likely to be seen around
the Blues, the Camas Prairie and mountain passes. There is the
potential for some snow even around the higher Palouse, including
the Pullman area, this morning.
Temperatures are expected to be held much below normal under the
cool core of the upper low. This means many areas struggling to
get into the 50s today. As for overnight lows tonight into
Thursday morning, we will have to monitor reading for potential
freezing warnings. Possible locations include the Okanogan
Highlands through the northern Panhandle, as well as the Palouse.
/J. Cote`
Thursday through Tuesday...Model agreement is quite good through
Friday...with some deterioration in detail commonality after
Friday but still display reasonable agreement regarding the over
all flow regime over and near the forecast area.
Thursday through Friday the upper level closed low is firmly
planted over the forecast area. The deformation band of persistent
and frequent showers currently entering the region will be off to
the north over southern BC and Alberta by Thursday morning...but
the forecast area will be under the direct influence of the low
center cold pool aloft with minor vorticity spokes available to
gin up showers in this weakly unstable and moist air mass. This
argues for a cool and showery regime with plenty of clouds and the
possibility of some fairly weak and isolated thunderstorms.
Impossible to nail down these sub-synoptic inter-trough
disturbances at this time...but suffice it to say just about
anywhere in the forecast area will be at risk for a shower or two
each day with the best chance over the mountains ringing the basin.
The holiday weekend harbors no better news for outdoor
enthusiasts. The good news is that the stubborn upper low will
weaken and become less coherent...but the bad news is a general
troffy pattern will remain over the region through the weekend.
Both the latest GFS and ECMWF place the axis of this opening
system/trough off the coast...which implies warmer temperatures in
a pre-trough southwest flow regime. However the area will remain
under cyclonic difluent flow aloft with likely a few sub-synoptic
disturbances rounding this flow Saturday through Monday. This
overall pattern does not suggest a particularly wet period...but
the risk of showers...particularly over the northern and eastern
mountains will present itself each day. Both models hint that the
highest risk of showers associated with a stronger disturbance
will be on Sunday and focused over the southeast and Idaho
Panhandle.
Tuesday the flow becomes a bit more progressive...but also brings
the threat of a stronger wave and surface occlusion to enhance
chances of rain once again.
Overall...there is high confidence of a distinctly unsettled and
occasionally showery regime right through the next week with low
confidence in timing any periods of heightened shower activity.
Temperatures will start out below normal Thursday and gradually
achieve seasonably normal values this weekend. /Fugazzi
&&
.AVIATION...
06Z TAFS: Several bands of rain are expected over eastern Washington
and northern Idaho tonight into Wednesday. One band will remain
nearly stationary over the far NE corner of WA and Nrn ID through
Wed aftn. A second disturbance will bring -shra and isold -tsra to
the KMWH-KEAT area tonight which will linger through much of the day
Wednesday. Showers will also expand into SE WA and Lewiston area
and spread northward toward KGEG-KCOE. Overall...the air mass will
be rather moist and any breaks will lead to periods of overnight fog
or stratus until either winds incr or pcpn returns. This is a low
confidence forecast across the board for timing and reductions in
cigs for most locations. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 50 36 61 44 62 41 / 80 20 20 10 50 40
Coeur d`Alene 48 35 61 41 61 40 / 90 20 20 20 50 60
Pullman 50 34 61 40 58 40 / 70 20 20 20 60 50
Lewiston 58 39 67 46 65 46 / 50 20 20 20 60 50
Colville 54 36 66 41 69 40 / 90 60 30 20 40 50
Sandpoint 49 35 60 40 62 39 / 100 70 30 20 50 60
Kellogg 46 34 56 42 58 41 / 90 40 30 40 60 60
Moses Lake 59 40 67 45 70 44 / 50 20 30 20 30 20
Wenatchee 55 40 65 45 66 46 / 60 40 40 20 30 20
Omak 56 36 66 41 69 42 / 70 50 40 20 30 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Flood Watch through this evening for Northern Panhandle.
WA...Flood Watch through this evening for Northeast Mountains.
&&
$$
000
FXUS66 KOTX 220554
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1055 PM PDT Tue May 21 2013
.SYNOPSIS...
A strong cold front will sweep through the region this afternoon
into this evening with showers...a chance of thunderstorms and
breezy winds. Cool and showery weather will continue through much
of the week, but with some improvement for the holiday weekend.
&&
.DISCUSSION...
Second update for tonight: We have gone ahead and issued an areal
flood watch for the northeastern corner of WA and Northern Idaho
Panhandle. 00z guidance has come in just as wet as the 18z which
brings the moderate band of pcpn currently moving into these
locations stalls the boundary through Wednesday afternoon. This
results in good model agreement of 1-1.5" of rainfall over
northern Stevens...Pend Oreille...Boundary...and portions of
Bonner County. Some of these locations...already received 0.25" to
0.50" inches of rainfall today with thunderstorms. In addition,
snow levels remain high under this axis of moisture which will add
to runoff until snow levels lower near 4K AGL around 18z
Wednesday.
Upstream...showers and isolated thunderstorms are beginning to
expand into the southwestern Columbia Basin and Wenatchee Area.
The shortwave driving these showers will stretch with some of its
energy directed into the East Slopes and some toward southeastern
WA and the lower ID Panhandle likely to bring more rain and snow
overnight. This activity will need to be closely monitored for any
heavier showers migrating into the burn scars outside Wenatchee
but at this time...most models only bring around 0.15" with the
exception of the GFS which is closer to 0.40".
We made some changes to sky grids and pcpn chances through the
next few hours to show a break for much of the central/northern
Basin and northern East Slopes. /sb
&&
.AVIATION...
06Z TAFS: Several bands of rain are expected over eastern Washington
and northern Idaho tonight into Wednesday. One band will remain
nearly stationary over the far NE corner of WA and Nrn ID through
Wed aftn. A second disturbance will bring -shra and isold -tsra to
the KMWH-KEAT area tonight which will linger through much of the day
Wednesday. Showers will also expand into SE WA and Lewiston area
and spread northward toward KGEG-KCOE. Overall...the air mass will
be rather moist and any breaks will lead to periods of overnight fog
or stratus until either winds incr or pcpn returns. This is a low
confidence forecast across the board for timing and reductions in
cigs for most locations. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 41 51 37 61 44 61 / 20 80 20 30 10 40
Coeur d`Alene 42 48 36 61 41 60 / 100 90 30 30 20 50
Pullman 40 51 35 61 40 58 / 50 70 20 20 20 60
Lewiston 45 59 41 67 46 65 / 70 70 20 30 20 50
Colville 46 56 37 66 41 68 / 100 90 60 30 20 40
Sandpoint 45 50 37 60 40 62 / 100 100 70 40 20 40
Kellogg 42 44 35 57 42 57 / 100 90 70 30 40 60
Moses Lake 45 62 40 67 45 67 / 90 40 20 30 20 30
Wenatchee 44 57 40 65 45 65 / 90 40 30 40 20 30
Omak 44 59 36 66 41 68 / 20 80 50 40 20 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Flood Watch from 3 AM PDT Wednesday through Wednesday evening
for Northern Panhandle.
WA...Flood Watch from 3 AM PDT Wednesday through Wednesday evening
for Northeast Mountains.
&&
$$
000
FXUS66 KOTX 220506
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1006 PM PDT Tue May 21 2013
.SYNOPSIS...
A strong cold front will sweep through the region this afternoon
into this evening with showers...a chance of thunderstorms and
breezy winds. Cool and showery weather will continue through much
of the week, but with some improvement for the holiday weekend.
&&
.DISCUSSION...
Second update for tonight: We have gone ahead and issued an areal
flood watch for the northeastern corner of WA and Northern Idaho
Panhandle. 00z guidance has come in just as wet as the 18z which
brings the moderate band of pcpn currently moving into these
locations stalls the boundary through Wednesday afternoon. This
results in good model agreement of 1-1.5" of rainfall over
northern Stevens...Pend Oreille...Boundary...and portions of
Bonner County. Some of these locations...already received 0.25" to
0.50" inches of rainfall today with thunderstorms. In addition,
snow levels remain high under this axis of moisture which will add
to runoff until snow levels lower near 4K AGL around 18z
Wednesday.
Upstream...showers and isolated thunderstorms are beginning to
expand into the southwestern Columbia Basin and Wenatchee Area.
The shortwave driving these showers will stretch with some of its
energy directed into the East Slopes and some toward southeastern
WA and the lower ID Panhandle likely to bring more rain and snow
overnight. This activity will need to be closely monitored for any
heavier showers migrating into the burn scars outside Wenatchee
but at this time...most models only bring around 0.15" with the
exception of the GFS which is closer to 0.40".
We made some changes to sky grids and pcpn chances through the
next few hours to show a break for much of the central/northern
Basin and northern East Slopes. /sb
&&
.AVIATION...
00Z TAFS: Several bands of rain are expected over eastern Washington
and northern Idaho tonight into Wednesday. The threat of
thunderstorms will dwindle quickly this evening as strong low level
cooling invades the region behind a cold front. The 18Z NAM was used
a guidance for the TAFs. It appears that a light band of rain in the
Pullman and Spokane area between 00z-03z will decay and be followed
by another more organized band of light to moderate rain after 08z.
Ceilings in the cool and wet air mass will probably fall below 2000
feet at many of the airports in the region on Wednesday morning.
Afternoon showers are expected tomorrow under the upper level cold
pool with the highest concentration over the Cascades with the
favorable southeast upslope flow. /GKoch
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 41 51 37 61 44 61 / 20 80 20 30 10 40
Coeur d`Alene 42 48 36 61 41 60 / 100 90 30 30 20 50
Pullman 40 51 35 61 40 58 / 50 70 20 20 20 60
Lewiston 45 59 41 67 46 65 / 70 70 20 30 20 50
Colville 46 56 37 66 41 68 / 100 90 60 30 20 40
Sandpoint 45 50 37 60 40 62 / 100 100 70 40 20 40
Kellogg 42 44 35 57 42 57 / 100 90 70 30 40 60
Moses Lake 45 62 40 67 45 67 / 90 40 20 30 20 30
Wenatchee 44 57 40 65 45 65 / 90 40 30 40 20 30
Omak 44 59 36 66 41 68 / 20 80 50 40 20 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Flood Watch from 3 AM PDT Wednesday through Wednesday evening
for Northern Panhandle.
WA...Flood Watch from 3 AM PDT Wednesday through Wednesday evening
for Northeast Mountains.
&&
$$
000
FXUS66 KOTX 220242
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
742 PM PDT Tue May 21 2013
.SYNOPSIS...
A strong cold front will sweep through the region this afternoon
into this evening with showers...a chance of thunderstorms and
breezy winds. Cool and showery weather will continue through much
of the week, but with some improvement for the holiday weekend.
&&
.DISCUSSION...
Evening update: A large 540 decameter upper-level low is
currently centered off the northern Oregon Coast. The surface cold
front blew through the region this afternoon and now the trailing
midlevel cold front is slowly drifting across northeastern WA and
the ID Panhandle. A large swath of light to moderate rainfall is
accompanying the midlevel front with numerous locations receiving
upwards of 0.10 to 0.15 per hour. Dual Pol data suggest freezing
levels are dropping near 4000 feet under the heaviest
precipitation bands and are generally around 4800 ft in the
Cascades within the post frontal air mass. Lingering instability
remains along the MT/ID border and we continue to see isolated to
scattered thunderstorms which could impact locations such as
Bonners Ferry...Eastport...Clark Fork...and Prichard for the next
few hours. Models are in good agreement that the midlevel front
will continue to slowly drift north and east overnight taking the
steady pcpn with it. Upon reaching the far northeastern corner of
WA and the Idaho Panhandle...models do not indicate much movement
until perhaps late Wednesday morning and this is troublesome given
the amount of rainfall being generated over a similar area. As
such we will be closely monitoring rainfall amounts, especially
where thunderstorms moved through today for the potential of
localized flooding. At this time models produce anywhere from 0.80
to 1.50" of rain between 06z tonight and 06z Wednesday night.
We are seeing a break in the pcpn west and south of this front
with the exception of a few isolated thunderstorms in the
vicinity of Hanford, WA which will drift north toward southern
Grant and Adams County. The main pcpn threat behind the current
front will be on the next shortwave rotating within the broad low
pressure system. Cooling cloud tops can already been seen via IR
satellite imagery within the deformation axis of this wave along
the WA/OR border between Portland and Pendleton. All guidance
pivots this wave toward the E/NE overnight which will renew pcpn
chances along the southern tier of my CWA including the lower
Basin, Blue Mtns, Camas Prairie. Additional rainfall amounts up to
a quarter of an inch will be possible under this band through 12z.
&&
.AVIATION...
00Z TAFS: Several bands of rain are expected over eastern Washington
and northern Idaho tonight into Wednesday. The threat of
thunderstorms will dwindle quickly this evening as strong low level
cooling invades the region behind a cold front. The 18Z NAM was used
a guidance for the TAFs. It appears that a light band of rain in the
Pullman and Spokane area between 00z-03z will decay and be followed
by another more organized band of light to moderate rain after 08z.
Ceilings in the cool and wet air mass will probably fall below 2000
feet at many of the airports in the region on Wednesday morning.
Afternoon showers are expected tomorrow under the upper level cold
pool with the highest concentration over the Cascades with the
favorable southeast upslope flow. /GKoch
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 41 51 37 61 44 61 / 100 80 20 30 10 40
Coeur d`Alene 42 48 36 61 41 60 / 100 90 30 30 20 50
Pullman 40 51 35 61 40 58 / 70 70 20 20 20 60
Lewiston 45 59 41 67 46 65 / 70 70 20 30 20 50
Colville 46 56 37 66 41 68 / 100 90 60 30 20 40
Sandpoint 45 50 37 60 40 62 / 100 100 70 40 20 40
Kellogg 42 44 35 57 42 57 / 100 90 70 30 40 60
Moses Lake 45 62 40 67 45 67 / 70 40 20 30 20 30
Wenatchee 44 57 40 65 45 65 / 70 40 30 40 20 30
Omak 44 59 36 66 41 68 / 80 80 50 40 20 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 212352
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
452 PM PDT Tue May 21 2013
.SYNOPSIS...
A strong cold front will sweep through the region this afternoon
into this evening with showers...a chance of thunderstorms and
breezy winds. Cool and showery weather will continue through much
of the week, but with some improvement for the holiday weekend.
&&
.DISCUSSION...
Tonight and Wednesday: A Big weather change is expected. A strong
cold front has moved through eastern Washington and will exit
north Idaho this evening. A band of strong thunderstorms will
march across northeast Washington and north Idaho by early this
evening with small hail and gusty winds. Meanwhile, a deformation
band of steady rain will slowly move across the Columbia Basin
into the Idaho panhandle through the night as a deep upper level
low creeps from the Washington coast inland. Wet and cool
conditions will prevail into Wednesday as the upper level low
wobbles east of the Cascades during the day. Then a secondary band
of showers develop associated with the low center, which looks
like it tracks across the Columbia basin Wednesday morning and
toward the northeast Washington mountains and Idaho panhandle by
late afternoon and early evening. Snow levels will plummet
overnight, especially across from the Cascades, to the Blue
mountains, Palouse and into Central Idaho panhandle by Wednesday
morning, with snow down to around 3k ft. The second deformation
band will lift toward the Canadian border by afternoon while snow
levels only creep up to 4k ft by afternoon. What little daytime
heating expected along with the cold air aloft will raise
instability slightly and lead to a small chance of thunderstorms
in the Cascades and Blue mountains by Wednesday afternoon.
Temperatures will be significantly cooler of 10 to 15 degrees from
today. /rfox.
Wednesday Night and Thursday: The Inland Northwest should
experience a bit of a drying trend Wednesday night into Thursday.
The large deformation band associated with a bent back frontal
occlusion is expected to migrate toward the Canadian Rockies
Wednesday night and remain well north and east of the region
through Thursday. Models have been in decent agreement the last
several runs that there should be a relative lull in precipitation
over the northern Panhandle and southeast British Columbia on
Thursday. This is good news for the swollen Kootenai and Moyie
Rivers. On Thursday, our attention will turn toward the center of
the 500mb low over western Washington and it`s upper level cold
pool. Moisture and instability profiles suggest that the best
chances for showers on Thursday will be over the Cascades and
possibly the Okanogan Highlands. The NAM and GFS both prog upwards
of 200 J/KG of surface based CAPE over the Cascades Thursday
afternoon. This won`t be a particularly moisture-rich environment
and 700-500mb flow suggests storm motion around 20 mph. However,
we will monitor any convection over the Cascades closely this year
over the burn scar areas near Wenatchee and Chelan. These scars
will have a heightened potential for mud slides.
Friday and Friday Night: The 12z models suggest that the focus for
showers will shift from the Cascades on Thursday toward northeast
Oregon and southeast Washington on Friday. The GFS and ECMWF are
in good agreement that the 500mb cold pool will drift into
northern Oregon by Friday afternoon. The highest chances for
showers looks to be in the Lewiston, Pomeroy, Winchester, Pullman
and St. Maries zones. Thunderstorms may need to be added to the
forecast (SE Washington and central/southern ID Panhandle) for
Friday afternoon if the models continue to advertise this track
and timing of the 500mb cold pool. /GKoch
Saturday through Tuesday...The Inland Northwest will continue to see
unsettled conditions through the holiday weekend. The upper low and
associated synoptic forcing will weaken so precipitation should be
more scattered in nature. Orographic ascent will become a more
significant forcing mechanism so there will be a better chance of
showers for the rising terrain north and east of the basin. With
less cloud cover and precip expected, temperatures will trend closer
to seasonal normals. /Kelch
&&
.AVIATION...
00Z TAFS: Several bands of rain are expected over eastern Washington
and northern Idaho tonight into Wednesday. The threat of
thunderstorms will dwindle quickly this evening as strong low level
cooling invades the region behind a cold front. The 18Z NAM was used
a guidance for the TAFs. It appears that a light band of rain in the
Pullman and Spokane area between 00z-03z will decay and be followed
by another more organized band of light to moderate rain after 08z.
Ceilings in the cool and wet air mass will probably fall below 2000
feet at many of the airports in the region on Wednesday morning.
Afternoon showers are expected tomorrow under the upper level cold
pool with the highest concentration over the Cascades with the
favorable southeast upslope flow. /GKoch
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 41 51 37 61 44 61 / 80 80 20 30 10 40
Coeur d`Alene 42 48 36 61 41 60 / 80 90 30 30 20 50
Pullman 40 51 35 61 40 58 / 80 70 20 20 20 60
Lewiston 45 59 41 67 46 65 / 70 70 20 30 20 50
Colville 46 56 37 66 41 68 / 90 90 60 30 20 40
Sandpoint 45 50 37 60 40 62 / 90 100 70 40 20 40
Kellogg 42 44 35 57 42 57 / 90 90 70 30 40 60
Moses Lake 45 62 40 67 45 67 / 60 40 20 30 20 30
Wenatchee 44 57 40 65 45 65 / 60 40 30 40 20 30
Omak 44 59 36 66 41 68 / 70 80 50 40 20 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 212138
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
238 PM PDT Tue May 21 2013
.SYNOPSIS...
A strong cold front will sweep through the region this afternoon
into this evening with showers...a chance of thunderstorms and
breezy winds. Cool and showery weather will continue through much
of the week, but with some improvement for the holiday weekend.
&&
.DISCUSSION...
Tonight and Wednesday: A Big weather change is expected. A strong
cold front has moved through eastern Washington and will exit
north Idaho this evening. A band of strong thunderstorms will
march across northeast Washington and north Idaho by early this
evening with small hail and gusty winds. Meanwhile, a deformation
band of steady rain will slowly move across the Columbia Basin
into the Idaho panhandle through the night as a deep upper level
low creeps from the Washington coast inland. Wet and cool
conditions will prevail into Wednesday as the upper level low
wobbles east of the Cascades during the day. Then a secondary band
of showers develop associated with the low center, which looks
like it tracks across the Columbia basin Wednesday morning and
toward the northeast Washington mountains and Idaho panhandle by
late afternoon and early evening. Snow levels will plummet
overnight, especially across from the Cascades, to the Blue
mountains, Palouse and into Central Idaho panhandle by Wednesday
morning, with snow down to around 3k ft. The second deformation
band will lift toward the Canadian border by afternoon while snow
levels only creep up to 4k ft by afternoon. What little daytime
heating expected along with the cold air aloft will raise
instability slightly and lead to a small chance of thunderstorms
in the Cascades and Blue mountains by Wednesday afternoon.
Temperatures will be significantly cooler of 10 to 15 degrees from
today. /rfox.
Wednesday Night and Thursday: The Inland Northwest should
experience a bit of a drying trend Wednesday night into Thursday.
The large deformation band associated with a bent back frontal
occlusion is expected to migrate toward the Canadian Rockies
Wednesday night and remain well north and east of the region
through Thursday. Models have been in decent agreement the last
several runs that there should be a relative lull in precipitation
over the northern Panhandle and southeast British Columbia on
Thursday. This is good news for the swollen Kootenai and Moyie
Rivers. On Thursday, our attention will turn toward the center of
the 500mb low over western Washington and it`s upper level cold
pool. Moisture and instability profiles suggest that the best
chances for showers on Thursday will be over the Cascades and
possibly the Okanogan Highlands. The NAM and GFS both prog upwards
of 200 J/KG of surface based CAPE over the Cascades Thursday
afternoon. This won`t be a particularly moisture-rich environment
and 700-500mb flow suggests storm motion around 20 mph. However,
we will monitor any convection over the Cascades closely this year
over the burn scar areas near Wenatchee and Chelan. These scars
will have a heightened potential for mud slides.
Friday and Friday Night: The 12z models suggest that the focus for
showers will shift from the Cascades on Thursday toward northeast
Oregon and southeast Washington on Friday. The GFS and ECMWF are
in good agreement that the 500mb cold pool will drift into
northern Oregon by Friday afternoon. The highest chances for
showers looks to be in the Lewiston, Pomeroy, Winchester, Pullman
and St. Maries zones. Thunderstorms may need to be added to the
forecast (SE Washington and central/southern ID Panhandle) for
Friday afternoon if the models continue to advertise this track
and timing of the 500mb cold pool. /GKoch
Saturday through Tuesday...The Inland Northwest will continue to see
unsettled conditions through the holiday weekend. The upper low and
associated synoptic forcing will weaken so precipitation should be
more scattered in nature. Orographic ascent will become a more
significant forcing mechanism so there will be a better chance of
showers for the rising terrain north and east of the basin. With
less cloud cover and precip expected, temperatures will trend closer
to seasonal normals. /Kelch
&&
.AVIATION...
18Z TAFS: A cold front will sweep through the TAF sites today
lowering cigs, showers, a wind switch with gusty winds. The front
will push from KEAT to KMWH through 21z, and then march to the KGEG
vcnty, KPUW and KLWS toward 00z. Anticipate light high based showers
ahead of the front with the potential for thunderstorms. The best
chance for thunderstorms will be north and east of KGEG this
afternoon. Behind the front, expect cigs to continue to lower
overnight with steady light rain. Snow levels will drop to 4-5k ft
overnight. Cigs will be nearing MVFR by 12z. The rain will taper off
to shower by Wednesday morning. /rfox.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 41 51 37 61 44 61 / 80 80 20 30 10 40
Coeur d`Alene 42 48 36 61 41 60 / 80 90 30 30 20 50
Pullman 40 51 35 61 40 58 / 80 70 20 20 20 60
Lewiston 45 59 41 67 46 65 / 70 70 20 30 20 50
Colville 46 56 37 66 41 68 / 90 90 60 30 20 40
Sandpoint 45 50 37 60 40 62 / 90 100 70 40 20 40
Kellogg 42 44 35 57 42 57 / 90 90 70 30 40 60
Moses Lake 45 62 40 67 45 67 / 60 40 20 30 20 30
Wenatchee 44 57 40 65 45 65 / 60 40 30 40 20 30
Omak 44 59 36 66 41 68 / 70 80 50 40 20 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 211736
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1036 AM PDT Tue May 21 2013
.SYNOPSIS...
The mild spring weather will come to an end. A strong cold
front will sweep through the region today and this evening with
showers...a chance of thunderstorms and breezy winds. Cool and
showery weather will continue through much of the week, but will
improvement a bit for the holiday weekend.
&&
.DISCUSSION...
Updated the forecast to keep up on the quickly changing pattern
today. A deep upper level low is rotating to the WA coast while a
strong cold front has slipped east of the Cascades and roughly
extends from Chelan to Hanford. Radar shows a dense line of
showers along and ahead of the front. Embedded thunderstorms were
reported early this morning which coupled with the mid level
instability, but the lightning strikes have waned in the last
hour. Local heavy downpours accompanied the thunderstorms and
Wenatchee saw 0.14" in less than an hour. The front will slowly
sweep east and take on a negative tilt through the day. Not
expected much temperature rises today in the Cascades behind the
front. Meanwhile, the Idaho panhandle and extreme eastern WA will
warm up into the lower 70s with rising dewpoints. Instability will
be on the rise this afternoon in this area with Capes reaching
500-700 j/kg. This coupled with increased 0-6km speed shear and
low level directional shear ahead of the front, has the potential
for strong thunderstorms will some organization. The cons for
strong thunderstorm development will be the increase of mid and
high clouds which may cap the activity. Will continue to monitor.
/rfox.
&&
.AVIATION...
18Z TAFS: A cold front will sweep through the TAF sites today
lowering cigs, showers, a wind switch with gusty winds. The front
will push from KEAT to KMWH through 21z, and then march to the KGEG
vcnty, KPUW and KLWS toward 00z. Anticipate light high based showers
ahead of the front with the potential for thunderstorms. The best
chance for thunderstorms will be north and east of KGEG this
afternoon. Behind the front, expect cigs to continue to lower
overnight with steady light rain. Snow levels will drop to 4-5k ft
overnight. Cigs will be nearing MVFR by 12z. The rain will taper off
to shower by Wednesday morning. /rfox.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 70 41 51 36 61 42 / 30 90 90 40 30 30
Coeur d`Alene 72 41 48 36 59 41 / 30 90 90 50 40 40
Pullman 70 38 51 35 60 41 / 20 80 80 30 40 40
Lewiston 78 44 59 41 66 46 / 40 60 70 30 30 40
Colville 74 45 55 37 66 41 / 50 90 90 60 50 40
Sandpoint 73 43 50 36 59 39 / 30 90 90 80 40 50
Kellogg 75 40 44 34 55 40 / 30 90 90 70 50 50
Moses Lake 69 43 62 40 68 44 / 70 50 30 30 30 30
Wenatchee 63 43 58 42 65 45 / 70 60 40 40 50 30
Omak 66 43 59 38 66 41 / 80 80 70 50 50 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 211647
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
947 AM PDT Tue May 21 2013
.SYNOPSIS...
The mild spring weather will come to an end. A strong cold
front will sweep through the region today and this evening with
showers...a chance of thunderstorms and breezy winds. Cool and
showery weather will continue through much of the week, but will
improvement a bit for the holiday weekend.
&&
.DISCUSSION...
Updated the forecast to keep up on the quickly changing pattern
today. A deep upper level low is rotating to the WA coast while a
strong cold front has slipped east of the Cascades and roughly
extends from Chelan to Hanford. Radar shows a dense line of
showers along and ahead of the front. Embedded thunderstorms were
reported early this morning which coupled with the mid level
instability, but the lightning strikes have waned in the last
hour. Local heavy downpours accompanied the thunderstorms and
Wenatchee saw 0.14" in less than an hour. The front will slowly
sweep east and take on a negative tilt through the day. Not
expected much temperature rises today in the Cascades behind the
front. Meanwhile, the Idaho panhandle and extreme eastern WA will
warm up into the lower 70s with rising dewpoints. Instability will
be on the rise this afternoon in this area with Capes reaching
500-700 j/kg. This coupled with increased 0-6km speed shear and
low level directional shear ahead of the front, has the potential
for strong thunderstorms will some organization. The cons for
strong thunderstorm development will be the increase of mid and
high clouds which may cap the activity. Will continue to monitor.
/rfox.
&&
.AVIATION...
12Z TAFS: A cold front moves from the Cascades to Idaho trough
the next 12-18 hours, while the center of an upper low swings in
from the west/southwest tonight into Wednesday morning. The front
will bring an increasing area of rain near the western TAF sites
this morning and early afternoon. Scattered showers will develop
further east this afternoon, while a steadier band of
precipitation is expected to come by late afternoon and evening
with the cold front. A chance of thunderstorms also exists
throughout much of the region, with the best chance for organized
activity north and east of KGEG. Storms may be locally strong with
gusty winds/small hail. Tonight the incoming upper low is expected
to keep precipitation chances high across eastern TAF sites. Local
MVFR cigs are possible in the more persistent precipitation. Colder
air accompanying the upper low will allow some snow to mix in
toward Wednesday morning but surface temperatures are expected to
limit the accumulation threat below 3000 feet. /J. Cote`
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 70 41 51 36 61 42 / 30 90 90 40 30 30
Coeur d`Alene 72 41 48 36 59 41 / 30 90 90 50 40 40
Pullman 70 38 51 35 60 41 / 20 80 80 30 40 40
Lewiston 78 44 59 41 66 46 / 40 60 70 30 30 40
Colville 74 45 55 37 66 41 / 50 90 90 60 50 40
Sandpoint 73 43 50 36 59 39 / 30 90 90 80 40 50
Kellogg 75 40 44 34 55 40 / 30 90 90 70 50 50
Moses Lake 69 43 62 40 68 44 / 70 50 30 30 30 30
Wenatchee 63 43 58 42 65 45 / 70 60 40 40 50 30
Omak 66 43 59 38 66 41 / 80 80 70 50 50 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 211143
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
443 AM PDT Tue May 21 2013
.SYNOPSIS...
The mild spring weather will come to an end. A strong cold
front will sweep through the region Tuesday through early
Wednesday with showers likely, a chance of thunderstorms, breezy
winds and cooler temperatures. Cool and showery conditions will
prevail through much of the week, but will improvement a bit for
the holiday weekend.
&&
.DISCUSSION...
Today and tonight: a strong cold front moves into the region,
with increasing rain and the potential for thunderstorms, with the
added threat of snow coming to some of the low lands late tonight
into Wednesday morning. This morning satellite imagery showed the
cold front advancing onto the Pacific Northwest coast and radar
showed a swath of rain extending about 100-150 miles east of it.
Deep layer lift with the cold front and supporting jet stream
coming around the upper low is expected to sustain the precipitation.
So precipitation that is just coming into the Cascades is expected
to expand across central Washington through the morning and early
afternoon. More widely scattered showers are expected to develop
across eastern Washington and north Idaho this afternoon, before
the steadier band of precipitation comes here late this afternoon
and evening with the cold front. The center of the upper low and
linked strong vorticity max comes onshore near northwest OR this
evening, before swinging toward the central WA/OR border
overnight. This will sustain the deep layer lift and keep
precipitation chances high tonight across the eastern third of
Washington, northern Idaho and west to southwest across the
Okanogan through Cascades.
As for the thunderstorm potential, convective parameters indicate
increasing CAPE and unstable LI value through this morning and
afternoon. The highest CAPE and most unstable LI values and so
highest thunderstorm threat is projected to be from the Okanogan
Highlands into the northeast mountains and Idaho Panhandle.
However some low-grade CAPE and the High Level Total Totals
instability parameter indicating values between 30-36 C back into
the Okanogan Valley through Waterville Plateau and Cascades, some
thunder cannot be ruled out here either. Lastly models indicate
some modest 0-6km shear across the region. Where instability is
best values are between 35-50kts. This support the potential for a
few organized and stronger thunderstorms, with a threat of hail
and strong winds. However is the cold front passes quicker this
potential will be limited.
Temperatures will vary greatly from the Idaho Panhandle to the
Cascades today. The incoming cold front and precipitation is
expected to keep temperatures across the western Basin through
Cascades relatively cool and below normal. The eastern third of
Washington and northern Idaho, however, will see more sun and less
precipitation ahead of the cold front until later in the day. This
will hold temperatures closer to or slightly above normal.
Overnight into Wednesday morning colder air begins to punch in
with the center of the upper low. Across the Cascades through the
Palouse and Camas Prairie, models show 850 mb temperatures
dropping to between 0 and -2 C. This suggests snow levels dropping
to near 3000 feet across this region. So some snow remains in the
forecast, even around Pullman. Accumulations should be limited by
surface temperatures generally remaining above freezing. The
exception will be in the higher Cascades and potentially around
the Blue Mountains and higher Camas Prairie, including near
Winchester. /J. Cote`
Wednesday and Wednesday Night: As we progress into the overnight
hours we will continue to see widespread rain for the Inland NW
and potentially moderate precipitation for parts of NE Washington
and the Northern Idaho Panhandle especially in the higher
elevations. A major swing in temperatures will also be accompanied
by the strong cold front.
Mentioning the higher amounts of QPF we can base this off of not
only the front slowing its progression in the mentioned
areas...but also a strong jet will be supportive of higher
precip. intensity. The key to all of this relating to potential
impacts of flooding will be the snow levels. For this forecast the
snow levels were only slightly adjusted but with current forecast
levels much of the precip that falls in the higher elevations will
fall as wet snow rather than rain and this will help minimize
the flooding impacts. If all precip were to fall as rain the
flooding potential for rivers and streams would be elevated due
to higher amounts of direct runoff...but given the current
scenario the snowfall will act as a storage mechanism for much of
the liquid and let it slowly melt and contribute to streams as
temperatures warm back up.
Other changes that were made to the forecast would be even further
increasing the POPs for the NE part of Washington and the ID
Panhandle for Wednesday. Although POPs were increased the over QPF
amounts were trimmed back a little especially for the east slopes
of the Northern Cascades as new model runs show slightly lower
amounts. QPF was also trimmed for NE part of the forecast
area...but remain high for the time frame which will still lead
to rises in the streams and rivers. All rivers minus the Okanogan
River near Tonasket is currently forecast to remain below flood
stage and the Okanogan will only reach minor flood stage. In
general this period will see temps drop significantly from the
previous day (nearly 30F in some areas) and some breezy conditions
as the front pushes through the area. /Fliehman
Thursday through Monday...Unsettled and cool conditions will
continue through the extended period. Models are in very good
agreement in holding a deep upper level low right over or very
close to the forecast area through Friday...which is a high
confidence recipe for showery conditions just about everywhere in
the forecast area. The latest GFS and EC models both sense a
secondary deformation area transiting the region from south to
north on Friday which may enhance the density of showers on this
day especially across the northern tier zones.
For the upcoming holiday weekend model consensus begins to break
down but both models depict a weakening of the coherence of this
upper low...an opening up and broadening trend into a general
trough over the region (GFS) or a migration of the upper low
center into southern Canada (ECMWF). Both solutions suggest a
continued unsettled and showery regime...but showers may not be as
prevalent as when the upper low was directly over the region. At
this time the weekend does not look like a wash-out...but none the
less iffy for outdoor activities...with guarded optimism that the
densest shower activity will occur over the mountains north and
east of the basin. Temperatures through the upcoming week will
start out well below normal but slowly add a degree or two each
day and top out around normal by next Sunday and Monday. /Fugazzi
&&
.AVIATION...
12Z TAFS: A cold front moves from the Cascades to Idaho trough
the next 12-18 hours, while the center of an upper low swings in
from the west/southwest tonight into Wednesday morning. The front
will bring an increasing area of rain near the western TAF sites
this morning and early afternoon. Scattered showers will develop
further east this afternoon, while a steadier band of
precipitation is expected to come by late afternoon and evening
with the cold front. A chance of thunderstorms also exists
throughout much of the region, with the best chance for organized
activity north and east of KGEG. Storms may be locally strong with
gusty winds/small hail. Tonight the incoming upper low is expected
to keep precipitation chances high across eastern TAF sites. Local
MVFR cigs are possible in the more persistent precipitation. Colder
air accompanying the upper low will allow some snow to mix in
toward Wednesday morning but surface temperatures are expected to
limit the accumulation threat below 3000 feet. /J. Cote`
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 73 41 51 36 61 42 / 30 90 90 40 30 30
Coeur d`Alene 75 41 48 36 59 41 / 30 90 90 50 40 40
Pullman 72 38 51 35 60 41 / 10 80 80 30 40 40
Lewiston 80 44 59 41 66 46 / 30 60 70 30 30 40
Colville 76 45 55 37 66 41 / 50 90 90 60 50 40
Sandpoint 76 43 50 36 59 39 / 30 90 90 80 40 50
Kellogg 75 40 44 34 55 40 / 30 90 90 70 50 50
Moses Lake 71 43 62 40 68 44 / 70 50 30 30 30 30
Wenatchee 63 43 58 42 65 45 / 60 60 40 40 50 30
Omak 69 43 59 38 66 41 / 80 80 70 50 50 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 210922
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
222 AM PDT Tue May 21 2013
.SYNOPSIS...
The mild spring weather will come to an end. A strong cold front will
sweep through the region Tuesday through early Wednesday with showers
likely, a chance of thunderstorms, breezy winds and cooler temperatures.
Cool and showery conditions will prevail through much of the week,
but will improvement a bit for the holiday weekend.
&&
.DISCUSSION...
Today and tonight: a strong cold front moves into the region,
with increasing rain and the potential for thunderstorms, with the
added threat of snow coming to some of the low lands late tonight
into Wednesday morning. This morning satellite imagery showed the
cold front advancing onto the Pacific Northwest coast and radar
showed a swath of rain extending about 100-150 miles east of it.
Deep layer lift with the cold front and supporting jet stream
coming around the upper low is expected to sustain the precipitation.
So precipitation that is just coming into the Cascades is expected
to expand across central Washington through the morning and early
afternoon. More widely scattered showers are expected to develop
across eastern Washington and north Idaho this afternoon, before
the steadier band of precipitation comes here late this afternoon
and evening with the cold front. The center of the upper low and
linked strong vorticity max comes onshore near northwest OR this
evening, before swinging toward the central WA/OR border
overnight. This will sustain the deep layer lift and keep
precipitation chances high tonight across the eastern third of
Washington, northern Idaho and west to southwest across the
Okanogan through Cascades.
As for the thunderstorm potential, convective parameters indicate
increasing CAPE and unstable LI value through this morning and
afternoon. The highest CAPE and most unstable LI values and so
highest thunderstorm threat is projected to be from the Okanogan
Highlands into the northeast mountains and Idaho Panhandle.
However some low-grade CAPE and the High Level Total Totals
instability parameter indicating values between 30-36 C back into
the Okanogan Valley through Waterville Plateau and Cascades, some
thunder cannot be ruled out here either. Lastly models indicate
some modest 0-6km shear across the region. Where instability is
best values are between 35-50kts. This support the potential for a
few organized and stronger thunderstorms, with a threat of hail
and strong winds. However is the cold front passes quicker this
potential will be limited.
Temperatures will vary greatly from the Idaho Panhandle to the
Cascades today. The incoming cold front and precipitation is
expected to keep temperatures across the western Basin through
Cascades relatively cool and below normal. The eastern third of
Washington and northern Idaho, however, will see more sun and less
precipitation ahead of the cold front until later in the day. This
will hold temperatures closer to or slightly above normal.
Overnight into Wednesday morning colder air begins to punch in
with the center of the upper low. Across the Cascades through the
Palouse and Camas Prairie, models show 850 mb temperatures
dropping to between 0 and -2 C. This suggests snow levels dropping
to near 3000 feet across this region. So some snow remains in the
forecast, even around Pullman. Accumulations should be limited by
surface temperatures generally remaining above freezing. The
exception will be in the higher Cascades and potentially around
the Blue Mountains and higher Camas Prairie, including near
Winchester. /J. Cote`
Wednesday and Wednesday Night: As we progress into the overnight
hours we will continue to see widespread rain for the Inland NW
and potentially moderate precipitation for parts of NE Washington and
the Northern Idaho Panhandle especially in the higher elevations.
A major swing in temperatures will also be accompanied by the
strong cold front.
Mentioning the higher amounts of QPF we can base this off of not
only the front slowing its progression in the mentioned
areas...but also a strong jet will be supportive of higher
precip. intensity. The key to all of this relating to potential
impacts of flooding will be the snow levels. For this forecast the
snow levels were only slightly adjusted but with current forecast
levels much of the precip that falls in the higher elevations will
fall as wet snow rather than rain and this will help minimize
the flooding impacts. If all precip were to fall as rain the
flooding potential for rivers and streams would be elevated due
to higher amounts of direct runoff...but given the current
scenario the snowfall will act as a storage mechanism for much of
the liquid and let it slowly melt and contribute to streams as
temperatures warm back up.
Other changes that were made to the forecast would be even further
increasing the POPs for the NE part of Washington and the ID
Panhandle for Wednesday. Although POPs were increased the over QPF
amounts were trimmed back a little especially for the east slopes
of the Northern Cascades as new model runs show slightly lower
amounts. QPF was also trimmed for NE part of the forecast
area...but remain high for the time frame which will still lead
to rises in the streams and rivers. All rivers minus the Okanogan
River near Tonasket is currently forecast to remain below flood
stage and the Okanogan will only reach minor flood stage. In
general this period will see temps drop significantly from the
previous day (nearly 30F in some areas) and some breezy conditions
as the front pushes through the area. /Fliehman
Thursday through Monday...Unsettled and cool conditions will
continue through the extended period. Models are in very good
agreement in holding a deep upper level low right over or very
close to the forecast area through Friday...which is a high
confidence recipe for showery conditions just about everywhere in
the forecast area. The latest GFS and EC models both sense a
secondary deformation area transiting the region from south to
north on Friday which may enhance the density of showers on this
day especially across the northern tier zones.
For the upcoming holiday weekend model consensus begins to break
down but both models depict a weakening of the coherence of this
upper low...an opening up and broadening trend into a general
trough over the region (GFS) or a migration of the upper low
center into southern Canada (ECMWF). Both solutions suggest a
continued unsettled and showery regime...but showers may not be as
prevalent as when the upper low was directly over the region. At
this time the weekend does not look like a wash-out...but none the
less iffy for outdoor activities...with guarded optimism that the
densest shower activity will occur over the mountains north and
east of the basin. Temperatures through the upcoming week will
start out well below normal but slowly add a degree or two each
day and top out around normal by next Sunday and Monday. /Fugazzi
&&
.AVIATION...
06Z TAFS: A deep area of low pressure will track into the region
during the next 24 hrs. Mid and high clouds will be on the increase
tonight and showers are expected to develop btwn KEAT-KOMK
during the early morning hrs with the slight potential for an
elevated t-storm. More alarming to the aviation community will
be the passage of a strong cold front through the region through
the aftn hrs. The front is expected to cross through KEAT/KMWH
and 18z and KGEG-KCOE-KPUW-KLWS near 21z. There is a decent
potential that showers will occur along the front and
thunderstorms will develop upon reaching the WA/ID border...some
which may become strong or severe over extreme NE WA and Nrn ID.
The frnt will also bring a wind shift to the W/SW and be breezy. A
secondary front will arrive btwn 00-06 focusing light to moderate
pcpn and potential for MVFR cigs frm KGEG-KCOE south to KPUW. Pcpn
may switch to snow at times Wednesday morning at KPUW. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 73 41 51 36 61 42 / 30 90 90 40 30 30
Coeur d`Alene 75 41 48 36 59 41 / 30 90 90 50 40 40
Pullman 72 38 51 35 60 41 / 10 80 80 30 40 40
Lewiston 80 44 59 41 66 46 / 30 60 70 30 30 40
Colville 76 45 55 37 66 41 / 50 90 90 60 50 40
Sandpoint 76 43 50 36 59 39 / 30 90 90 80 40 50
Kellogg 75 40 44 34 55 40 / 30 90 90 70 50 50
Moses Lake 71 43 62 40 68 44 / 70 50 30 30 30 30
Wenatchee 63 43 58 42 65 45 / 60 60 40 40 50 30
Omak 69 43 59 38 66 41 / 80 80 70 50 50 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 210538
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1040 PM PDT Mon May 20 2013
.SYNOPSIS...
The mild spring weather will come to an end. A strong cold front will
sweep through the region Tuesday with showers likely, a chance of
thunderstorms, breezy winds and cooler temperatures. Cool and
showery conditions will prevail through much of the week, but will
some improvements for the holiday weekend.
&&
.DISCUSSION...
Evening update: Just minor tweeks to the sky grids for this
evening as the forecast looks decent for the remainder of tonight.
The main focus will be a deep area of low pressure which continues
to barrel toward the WA Coast this evening and will bring a wide
array of weather to the Inland NW on Tuesday.
Rain has already spread on the WA Coast and this moisture will
begin to increase along and just east of the Cascades overnight.
Showers are expected to materialize after 12z (5AM) in these
areas and as the upper-level front approaches...there may be
enough midlevel instability to squeeze out an elevated
thunderstorm before 9AM.
The main thunderstorm threat will come mid to late afternoon and
continue into the early evening. 00Z NAM continues to advertise
upwards of 1000 J/kg of surface based CAPE across portions of NE
WA and Nrn ID Panhandle. GFS is lower but also carries a drier
boundary layer. Based on what happened today in conjunction with
MOS guidance...somewhere in between appears and decent forecast
for surface moisture. As for surface warming...models tend to
agree that the northeastern quadrant of my CWA will be prime
real estate for sunshine allowing sufficient surface warming
and temperatures in the 70`s. Remarkably, guidance is in good
agreement with the timing and placement of the sfc-800mb cold
front which will take on a negative tilt and punch across Ern WA
between 20-00z...and extend from Republic...Deer Park...St
Maries...to Kamiah by roughly 00z and continue east and north btwn
00-03z (5PM-8PM). 0-6km wind shear will be increasing near 40kts
or so and will also contain modest veering with height.
If all things come together as modeled...there is a good
possibility that thunderstorms will fire along the cold front and
potentially become strong to severe late across portions of
northeastern WA and the Northern Idaho Panhandle. We have issued a
weather story to address the locations which are most favored. At
this time, appears large hail will be the foremost threat but
damaging winds cannot be ruled out.
Something else which will need further addressing is the
precipitation threat behind the sfc-800mb cold front. The first
front will be the focus for thunderstorms but the secondary
mid and upper-level front will be the focus for heavier
precipitation with upwards of a quarter of an inch possible. There
may be enough midlevel instability to warrant mention of elevated
thunder briefly in the 3-6z period...focusing on the sw basin and
expanding NE overnight. This will mark the period when the cooler
air really arrives and snow levels will plummet. Bufkit data from
Pullman suggest precipitation will switch over to snow some point
in the middle of the night which appears plausible given strong
model agreement of 850mb temperatures near -1C so locations
generally above 2500 feet in the lower ID Panhandle and Cascades
could wake up to some wet snow falling. It is advertised to check
on pass conditions if traveling across the mountains Tuesday night
and Wednesday. /sb
&&
.AVIATION...
06Z TAFS: A deep area of low pressure will track into the region
during the next 24 hrs. Mid and high clouds will be on the increase
tonight and showers are expected to develop btwn KEAT-KOMK
during the early morning hrs with the slight potential for an
elevated t-storm. More alarming to the aviation community will
be the passage of a strong cold front through the region through
the aftn hrs. The front is expected to cross through KEAT/KMWH
arnd 18z and KGEG-KCOE-KPUW-KLWS near 21z. There is a decent
potential that showers will occur along the front and thunderstorms
will develop upon reaching the WA/ID border...some which may become
strong or severe over extreme NE WA and Nrn ID. The frnt will also
bring a wind shift to the W/SW and be breezy. A secondary front
will arrive btwn 00-06 focusing light to moderate pcpn and potential
for MVFR cigs frm KGEG-KCOE south to KPUW. Pcpn may switch to snow at
times Wednesday morning at KPUW. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 51 75 41 52 36 60 / 0 20 90 90 40 40
Coeur d`Alene 46 77 42 49 36 59 / 0 30 90 90 50 40
Pullman 48 73 39 51 35 60 / 0 10 80 80 30 40
Lewiston 52 81 45 59 40 67 / 0 10 80 70 30 40
Colville 45 78 43 55 37 64 / 0 50 90 80 60 50
Sandpoint 44 76 43 51 36 58 / 0 30 90 90 80 50
Kellogg 50 76 41 45 34 54 / 0 30 90 90 70 60
Moses Lake 51 73 43 63 40 68 / 0 50 50 30 30 30
Wenatchee 53 66 43 59 43 64 / 0 60 50 40 40 40
Omak 48 71 42 60 38 65 / 0 80 80 70 50 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 210416
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
916 PM PDT Mon May 20 2013
.SYNOPSIS...
The mild spring weather will come to an end. A strong cold front will
sweep through the region Tuesday with showers likely, a chance of
thunderstorms, breezy winds and cooler temperatures. Cool and
showery conditions will prevail through much of the week, but will
some improvements for the holiday weekend.
&&
.DISCUSSION...
Evening update: Just minor tweeks to the sky grids for this
evening as the forecast looks decent for the remainder of tonight.
The main focus will be a deep area of low pressure which continues
to barrel toward the WA Coast this evening and will bring a wide
array of weather to the Inland NW on Tuesday.
Rain has already spread on the WA Coast and this moisture will
begin to increase along and just east of the Cascades overnight.
Showers are expected to materialize after 12z (5AM) in these
areas and as the upper-level front approaches...there may be
enough midlevel instability to squeeze out an elevated
thunderstorm before 9AM.
The main thunderstorm threat will come mid to late afternoon and
continue into the early evening. 00Z NAM continues to advertise
upwards of 1000 J/kg of surface based CAPE across portions of NE
WA and Nrn ID Panhandle. GFS is lower but also carries a drier
boundary layer. Based on what happened today in conjunction with
MOS guidance...somewhere in between appears and decent forecast
for surface moisture. As for surface warming...models tend to
agree that the northeastern quadrant of my CWA will be prime
real estate for sunshine allowing sufficient surface warming
and temperatures in the 70`s. Remarkably, guidance is in good
agreement with the timing and placement of the sfc-800mb cold
front which will take on a negative tilt and punch across Ern WA
between 20-00z...and extend from Republic...Deer Park...St
Maries...to Kamiah by roughly 00z and continue east and north btwn
00-03z (5PM-8PM). 0-6km wind shear will be increasing near 40kts
or so and will also contain modest veering with height.
If all things come together as modeled...there is a good
possibility that thunderstorms will fire along the cold front and
potentially become strong to severe late across portions of
northeastern WA and the Northern Idaho Panhandle. We have issued a
weather story to address the locations which are most favored. At
this time, appears large hail will be the foremost threat but
damaging winds cannot be ruled out.
Something else which will need further addressing is the
precipitation threat behind the sfc-800mb cold front. The first
front will be the focus for thunderstorms but the secondary
mid and upper-level front will be the focus for heavier
precipitation with upwards of a quarter of an inch possible. There
may be enough midlevel instability to warrant mention of elevated
thunder briefly in the 3-6z period...focusing on the sw basin and
expanding NE overnight. This will mark the period when the cooler
air really arrives and snow levels will plummet. Bufkit data from
Pullman suggest precipitation will switch over to snow some point
in the middle of the night which appears plausible given strong
model agreement of 850mb temperatures near -1C so locations
generally above 2500 feet in the lower ID Panhandle and Cascades
could wake up to some wet snow falling. It is advertised to check
on pass conditions if traveling across the mountains Tuesday night
and Wednesday. /sb
&&
.AVIATION...
00Z TAFS: A deep area of low pressure will track into the region
during the next 24 hrs. Mid and high clouds will be on the increase
tonight and showers are expected to develop along btwn KEAT-KOMK
during the early morning hrs with the slight potential for an
elevated t-storm. More alarming to the aviation community will
be the passage of a strong cold front through the region through
the aftn hrs. The front is expected to cross through KEAT/KMWH
arnd 18z and KGEG-KCOE-KPUW-KLWS near 21z. There is a decent
potential that thunderstorms will erupt along the front upon
reaching the WA/ID border...some which may become strong or severe
over NE WA and Nrn ID. Gusty W/SW winds are expected behind the
front along with steady pcpn aft 00z. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 51 75 41 52 36 60 / 0 20 90 90 40 40
Coeur d`Alene 46 77 42 49 36 59 / 0 30 90 90 50 40
Pullman 48 73 39 51 35 60 / 0 10 80 80 30 40
Lewiston 52 81 45 59 40 67 / 0 10 80 70 30 40
Colville 45 78 43 55 37 64 / 0 50 90 80 60 50
Sandpoint 44 76 43 51 36 58 / 0 30 90 90 80 50
Kellogg 50 76 41 45 34 54 / 0 30 90 90 70 60
Moses Lake 51 73 43 63 40 68 / 0 50 50 30 30 30
Wenatchee 53 66 43 59 43 64 / 0 60 50 40 40 40
Omak 48 71 42 60 38 65 / 0 80 80 70 50 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 202358
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
455 PM PDT Mon May 20 2013
.SYNOPSIS...
The mild spring weather will come to an end. A strong cold front will
sweep through the region Tuesday with showers likely, a chance of
thunderstorms, breezy winds and cooler temperatures. Cool and
showery conditions will prevail through much of the week, but will
some improvements for the holiday weekend.
&&
.DISCUSSION...
Tonight: High pressure will weaken overnight as mid and high level
clouds increase across the region. Overnight lows will be mild as
winds turn out of the south to southeast and generate weak warm
air advection.
Tuesday: A deep Pacific low will swing toward the WA coast by
Tuesday morning and push a strong cold front across the Cascades
by late morning and reaching the Idaho by late afternoon. Deep
southerly flow aloft will over the region with the front taking on
a slight negative tilt through the day. There is the possibility
of some elevated convection ahead of the front Tuesday morning as
seen by the steeper mid level lapse rates from Wenatchee to Omak.
But once the front pushes through this area by midday, wet, cool
and stable conditions will develop rather quickly. The front will
march across the rest of eastern Washington while low level wind
profiles show increased directional shear, while the speed shear
increases aloft. Both the NAM and GFS point to a swath of
increased surface based instability from Republic, to Colville and
Newport to Sandpoint Tuesday afternoon ahead of the front. The
main threat will be large hail with gusty winds, and may even see
a few strong longer lived thunderstorms. Temperatures will range
greatly across the region from low to mid 60s in the Cascades to
mid to upper 70s in north Idaho. /rfox.
Tuesday night through Friday...Confidence is high that the Inland
Northwest will be under a cold and wet weather pattern during the
mid-week period. Models are in very good agreement on the large
scale pattern of a closed upper low settling over the region. This
system will benefit from strong upper level dynamics courtesy of a
90kt jet circling the low, placing much of the forecast area under
strong DifQ forcing. There will be plenty of moisture advection on
southerly flow ahead of the cold front, and this moisture will
continue to wrap around the low as it hovers over the region.
The area of highest concern will be the northeast quadrant where a
long-lived deformation zone will set up from Tuesday night through
Wednesday. A model comparison of mid level deformation zones leads
to higher confidence of where the heaviest precip will fall. For
those areas that show good model agreement, PoPs and QPF have been
increased. This shows the focus squarely on the northeast zones.
This is reinforced by areas of strong upper level forcing around the
periphery of the low along with a persistent theta-e ridge over
northeast.
QPF...We could be looking at an inch to an inch and a half of liquid
falling over the northern third of the forecast area over a 36 to 48
hour period. Around a half to three-fourths of an inch can be
expected for the highway 2 corridor with about a quarter inch for the
basin.
Temps/Snow levels...One saving grace will be that a good deal of the
QPF will be falling as snow in the higher mountains Wednesday. The
NAM shows cooler at 850 mb than other models but it has also been
more consistent, and now the 12Z ECMWF is trending cooler than its
previous run. Also taken into consideration is that with heavy rain,
there is the possibility of the column cooling further to trigger a
change-over to heavy snow. Snow levels across the Idaho panhandle
have been lowered to around 2500-3000 ft for Wednesday into
Wednesday night. There is a risk of accumulating snow for the high
mountains but also for an inch or two for the Idaho passes. The
mid to low level snow pack will not last long as temperatures will
return to near seasonal normals by the weekend.
As the system meanders around the Pacific Northwest it will start to
fill on Thursday and the best forcing will shift away from the
forecast area, into southern Oregon and southeast Idaho. We will
still be in a moist and modestly unstable environment, so if we see
any breaks in cloud cover we could see some convection firing up
over the southeast zones during the afternoon and evening hours
Thursday and Friday but confidence is rather low for now. /Kelch
Saturday through Monday: The longwave upper level trough will
linger over the Pacific Northwest and British Columbia over the
weekend and into early next week. Does this mean that the holiday
weekend will be a washout? Not necessarily. There is decent
agreement between the GFS, ECMWF and Canadian models that the
upper trough will become sheared apart by Saturday with one upper
low over the Canadian Rockies and another upper low digging into
northern California. It is tough to go with a dry forecast
Saturday and Sunday given the upper trofiness over the region, but
it does appear that the best forcing over the weekend will be both
north and south of our region. Showers in this regime will
probably be favored over the mountainous zones with the bulk of
the showers occurring during the afternoon and evening hours
(during peak heating). There is loose agreement between the 12Z
operational models that the aforementioned northern California low
will lift into Idaho on Monday. If this occurs, there will be more
widespread showers and possibly thunderstorms to round out the
holiday weekend on Monday. /GKoch
&&
.AVIATION...
00Z TAFS: A deep area of low pressure will track into the region
during the next 24 hrs. Mid and high clouds will be on the increase
tonight and showers are expected to develop along btwn KEAT-KOMK
during the early morning hrs with the slight potential for an
elevated t-storm. More alarming to the aviation community will
be the passage of a strong cold front through the region through
the aftn hrs. The front is expected to cross through KEAT/KMWH
arnd 18z and KGEG-KCOE-KPUW-KLWS near 21z. There is a decent
potential that thunderstorms will erupt along the front upon
reaching the WA/ID border...some which may become strong or severe
over NE WA and Nrn ID. Gusty W/SW winds are expected behind the
front along with steady pcpn aft 00z. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 51 75 41 52 36 60 / 0 20 90 90 40 40
Coeur d`Alene 46 77 42 49 36 59 / 0 30 90 90 50 40
Pullman 48 73 39 51 35 60 / 0 10 80 80 30 40
Lewiston 52 81 45 59 40 67 / 0 10 80 70 30 40
Colville 45 78 43 55 37 64 / 0 50 90 80 60 50
Sandpoint 44 76 43 51 36 58 / 0 30 90 90 80 50
Kellogg 50 76 41 45 34 54 / 0 30 90 90 70 60
Moses Lake 51 73 43 63 40 68 / 0 50 50 30 30 30
Wenatchee 53 66 43 59 43 64 / 0 60 50 40 40 40
Omak 48 71 42 60 38 65 / 0 80 80 70 50 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 202131
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
231 PM PDT Mon May 20 2013
.SYNOPSIS...
The mild spring weather will come to an end. A cold front will
sweep through the region Tuesday with showers likely, a chance of
thunderstorms, breezy winds and cooler temperatures. Cool and
showery conditions will prevail through much of the week, but will
some improvements for the holiday weekend.
&&
.DISCUSSION...
Tonight: High pressure will weaken overnight as mid and high level
clouds increase across the region. Overnight lows will be mild as
winds turn out of the south to southeast and generate weak warm
air advection.
Tuesday: A deep Pacific low will swing toward the WA coast by
Tuesday morning and push a strong cold front across the Cascades
by late morning and reaching the Idaho by late afternoon. Deep
southerly flow aloft will over the region with the front taking on
a slight negative tilt through the day. There is the possibility
of some elevated convection ahead of the front Tuesday morning as
seen by the steeper mid level lapse rates from Wenatchee to Omak.
But once the front pushes through this area by midday, wet, cool
and stable conditions will develop rather quickly. The front will
march across the rest of eastern Washington while low level wind
profiles show increased directional shear, while the speed shear
increases aloft. Both the NAM and GFS point to a swath of
increased surface based instability from Repubic, to Colville and
Newport to Sandpoint Tuesday afternoon ahead of the front. The
main threat will be large hail with gusty winds, and may even see
a few strong longer lived thunderstorms. Temperatures will range
greatly across the region from low to mid 60s in the Cascades to
mid to upper 70s in north Idaho. /rfox.
Tuesday night through Friday...Confidence is high that the Inland
Northwest will be under a cold and wet weather pattern during the
mid-week period. Models are in very good agreement on the large
scale pattern of a closed upper low settling over the region. This
system will benefit from strong upper level dynamics courtesy of a
90kt jet circling the low, placing much of the forecast area under
strong DifQ forcing. There will be plenty of moisture advection on
southerly flow ahead of the cold front, and this moisture will
continue to wrap around the low as it hovers over the region.
The area of highest concern will be the northeast quadrant where a
long-lived deformation zone will set up from Tuesday night through
Wednesday. A model comparison of mid level deformation zones leads
to higher confidence of where the heaviest precip will fall. For
those areas that show good model agreement, PoPs and QPF have been
increased. This shows the focus squarely on the northeast zones.
This is reinforced by areas of strong upper level forcing around the
periphery of the low along with a persistent theta-e ridge over
northeast.
QPF...We could be looking at an inch to an inch and a half of liquid
falling over the northern third of the forecast area over a 36 to 48
hour period. Around a half to three-fourths of an inch can be
expected for the highway 2 corridor with about a quarter inch for the
basin.
Temps/Snow levels...One saving grace will be that a good deal of the
QPF will be falling as snow in the higher mountains Wednesday. The
NAM shows cooler at 850 mb than other models but it has also been
more consistent, and now the 12Z ECMWF is trending cooler than its
previous run. Also taken into consideration is that with heavy rain,
there is the possibility of the column cooling further to trigger a
change-over to heavy snow. Snow levels across the Idaho panhandle
have been lowered to around 2500-3000 ft for Wednesday into
Wednesday night. There is a risk of accumulating snow for the high
mountains but also for an inch or two for the Idaho passes. The
mid to low level snow pack will not last long as temperatures will
return to near seasonal normals by the weekend.
As the system meanders around the Pacific Northwest it will start to
fill on Thursday and the best forcing will shift away from the
forecast area, into southern Oregon and southeast Idaho. We will
still be in a moist and modestly unstable environment, so if we see
any breaks in cloud cover we could see some convection firing up
over the southeast zones during the afternoon and evening hours
Thursday and Friday but confidence is rather low for now. /Kelch
Saturday through Monday: The longwave upper level trough will
linger over the Pacific Northwest and British Columbia over the
weekend and into early next week. Does this mean that the holiday
weekend will be a washout? Not necessarily. There is decent
agreement between the GFS, ECMWF and Canadian models that the
upper trough will become sheared apart by Saturday with one upper
low over the Canadian Rockies and another upper low digging into
northern California. It is tough to go with a dry forecast
Saturday and Sunday given the upper trofiness over the region, but
it does appear that the best forcing over the weekend will be both
north and south of our region. Showers in this regime will
probably be favored over the mountainous zones with the bulk of
the showers occurring during the afternoon and evening hours
(during peak heating). There is loose agreement between the 12Z
operational models that the aforementioned northern California low
will lift into Idaho on Monday. If this occurs, there will be more
widespread showers and possibly thunderstorms to round out the
holiday weekend on Monday. /GKoch
&&
.AVIATION...
18Z TAFS: High pressure will be over the TAF sites today with
light winds and VFR conditions. The patchy fog has lifted and
a few cumulus build ups will over the ridges to the north and east
of KGEG. Mid and high clouds will be on the increase tonight. A cold
front will reach the Cascades by 18z. Light showers are possible
ahead of the front in the KEAT vicinity before 18z. /rfox.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 51 75 41 52 36 60 / 0 20 90 90 40 40
Coeur d`Alene 46 77 42 49 36 59 / 0 30 90 90 50 40
Pullman 48 73 39 51 35 60 / 0 10 80 80 30 40
Lewiston 52 81 45 59 40 67 / 0 10 80 70 30 40
Colville 45 78 43 55 37 64 / 0 50 90 80 60 50
Sandpoint 44 76 43 51 36 58 / 0 30 90 90 80 50
Kellogg 50 76 41 45 34 54 / 0 30 90 90 70 60
Moses Lake 51 73 43 63 40 68 / 0 50 50 30 30 30
Wenatchee 53 66 43 59 43 64 / 0 60 50 40 40 40
Omak 48 71 42 60 38 65 / 0 80 80 70 50 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 201931
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1231 PM PDT Mon May 20 2013
.SYNOPSIS...
High pressure will provide mainly dry, warm conditions today. A
strong storm system enters the region on Tuesday and Wednesday,
with a good threat of rain, and the potential for thunderstorms.
The system will also usher in significantly cooler temperatures.
Cool, showery weather will continue into the weekend.
&&
.DISCUSSION...
Isolated showers will be develop on the ridges near Republic,
Colville and Metaline this afternoon. /rfox.
&&
.AVIATION...
18Z TAFS: High pressure will be over the TAF sites today with
light winds and VFR conditions. The patchy fog has lifted and
a few cumulus build ups will over the ridges to the north and east
of KGEG. Mid and high clouds will be on the increase tonight. A cold
front will reach the Cascades by 18z. Light showers are possible
ahead of the front in the KEAT vicinity before 18z. /rfox.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 71 51 75 43 51 38 / 0 0 20 90 90 40
Coeur d`Alene 71 46 77 45 48 39 / 0 0 20 90 90 50
Pullman 72 48 74 42 50 37 / 0 0 10 80 80 30
Lewiston 77 52 81 48 58 41 / 0 0 10 80 70 30
Colville 78 45 78 46 56 40 / 0 0 50 90 80 60
Sandpoint 71 44 77 45 52 39 / 10 0 20 90 90 80
Kellogg 66 50 76 44 46 37 / 10 0 10 90 90 70
Moses Lake 79 51 74 46 61 41 / 0 0 50 50 30 30
Wenatchee 77 53 67 46 58 43 / 0 0 60 50 40 40
Omak 78 48 71 46 60 40 / 0 0 80 80 70 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 201724
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1024 AM PDT Mon May 20 2013
.SYNOPSIS...
High pressure will provide mainly dry, warm conditions today. A
strong storm system enters the region on Tuesday and Wednesday,
with a good threat of rain, and the potential for thunderstorms.
The system will also usher in significantly cooler temperatures.
Cool, showery weather will continue into the weekend.
&&
.DISCUSSION...
Updated the forecast to tweak high temperatures slightly with
readings reaching the 70s by afternoon. The morning fog has
mostly burned off and expect a few cumulus build ups on the ridges
of northeast Washington and the Idaho panhandle from late morning
onward. High pressure will be over the region for the next 24
hours. /rfox.
&&
.AVIATION...
18Z TAFS: High pressure will be over the TAF sites today with
light winds and VFR conditions. The patchy fog has lifted and
a few cumulus build ups will over the ridges to the north and east
of KGEG. Mid and high clouds will be on the increase tonight. A cold
front will reach the Cascades by 18z. Light showers are possible
ahead of the front in the KEAT vicinity before 18z. /rfox.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 71 51 75 43 51 38 / 0 0 10 80 90 40
Coeur d`Alene 71 46 77 45 48 39 / 0 0 10 70 90 50
Pullman 72 48 74 42 50 37 / 0 0 0 70 70 30
Lewiston 77 52 81 48 58 41 / 0 0 0 60 70 30
Colville 78 45 78 46 56 40 / 0 0 40 80 80 60
Sandpoint 71 44 77 45 52 39 / 10 0 20 70 80 70
Kellogg 66 50 76 44 46 37 / 10 0 10 60 90 70
Moses Lake 79 51 74 46 61 41 / 0 0 40 50 30 30
Wenatchee 77 53 67 46 58 43 / 0 0 50 60 40 40
Omak 78 48 71 46 60 40 / 0 0 70 90 70 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 201648
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
948 AM PDT Mon May 20 2013
.SYNOPSIS...
High pressure will provide mainly dry, warm conditions today. A
strong storm system enters the region on Tuesday and Wednesday,
with a good threat of rain, and the potential for thunderstorms.
The system will also usher in significantly cooler temperatures.
Cool, showery weather will continue into the weekend.
&&
.DISCUSSION...
Updated the forecast to tweak high temperatures slightly with
readings reaching the 70s by afternoon. The morning fog has
mostly burned off and expect a few cumulus build ups on the ridges
of northeast Washington and the Idaho panhandle from late morning
onward. High pressure will be over the region for the next 24
hours. /rfox.
&&
.AVIATION...
12Z TAFS: High pressure moves across the region today. Patchy fog
will be found across ne WA/nrn ID through 15-17z, including in the
vcnty of the KGEG/KSFF/KCOE TAF sites. Otherwise dry/VFR
conditions are expected. Mid and high clouds increase from the
west late tonight into Tuesday morning as low pressure and a cold
front approach. /J. Cote`
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 71 51 75 43 51 38 / 0 0 10 80 90 40
Coeur d`Alene 71 46 77 45 48 39 / 0 0 10 70 90 50
Pullman 72 48 74 42 50 37 / 0 0 0 70 70 30
Lewiston 77 52 81 48 58 41 / 0 0 0 60 70 30
Colville 78 45 78 46 56 40 / 0 0 40 80 80 60
Sandpoint 71 44 77 45 52 39 / 10 0 20 70 80 70
Kellogg 66 50 76 44 46 37 / 10 0 10 60 90 70
Moses Lake 79 51 74 46 61 41 / 0 0 40 50 30 30
Wenatchee 77 53 67 46 58 43 / 0 0 50 60 40 40
Omak 78 48 71 46 60 40 / 0 0 70 90 70 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 201130
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
430 AM PDT Mon May 20 2013
.SYNOPSIS...
High pressure will provide mainly dry, warm conditions today. A
strong storm system enters the region on Tuesday and Wednesday,
with a good threat of rain, and the potential for thunderstorms.
The system will also usher in significantly cooler temperatures.
Cool, showery weather will continue into the weekend.
&&
.DISCUSSION...
Today and tonight: The Inland Northwest will be mainly dry and
mild under the influence of high pressure, while a pattern-changing
trough approaches the coast. The flow transitions from northwest
to southwest by late this afternoon as the mid-level ridge axis
shifts into central ID and north CA. Lingering low-grade convective
instability is depicted around the Panhandle mountains this afternoon.
However broad-scale subsidence with the ridge should keep the threat
of showers in the mountains, if any occur at all. Otherwise the
higher clouds that are reaching over the Cascades this morning
will continue to spread in, coupled with some afternoon cumulus
build-up. The developing southwest flow and subsidence will
promote milder temperatures today as compared to Sunday. Look for
temperatures near to slightly above normal. Tonight low pressure
and a cold front comes toward Cascades while the long-wave trough
deepens and takes on a more meridional (north-south) orientation.
This will bring increasing rain chances to the Cascades overnight
and primarily near the crest. Elsewhere clouds will begin to
thicken and lower from the west. /J. Cote`
Tuesday and Tuesday Night: A strong low pressure system will finally
push into our region on Tuesday bringing with it the almost certain
chance of widespread rain for all of the Inland NW. This system
has been slowly moving down from the Gulf of Alaska and once in
place near the area will persist for quite some time. Quite a slug
of moisture looks to push inland with the initial barrage with the
brunt of the rainfall occurring near the crests of the Cascades
and later pushing further into the forecast area to bring lighter
amounts east of the crests.
Timing on this system looks to be in good agreement amongst the
models with all models showing the initial rainfall reaching the
Cascade crests by Tuesday morning and pushing further east
throughout the day Tuesday and into the evening for the ID
Panhandle. Ahead of the strong cold front will be some instability
that could trigger some thunderstorms for the eastern part of WA
and the ID panhandle in part due to the strong daytime heating due
to the southerly flow and an increased moisture push associated
with the incoming system. Once sunset occurs and overnight cooling
begins most all convection will come to an abrupt end...but the
rain showers will persist into the overnight hours. Snow levels remain
high until the cold front passes behind the initial rain which will
lead to a transition from rain to snow in the high elevations of
mainly the Cascades. With a bulk of the precip falling as rain we
will see an immediate rise in the local streams and rivers which
will be something we will continue to monitor. Although temps drop
after the passing of the cold front along with snow levels...the
lower snow levels will lead to less direct runoff in turn allowing
some storage of water and allowing streams to not rise as rapidly
as if all QPF fell as rain. Overall this time frame will be
characterized as a transition period from warm and dry to wet and
cool for the entire region. /Fliehman
Wednesday through Sunday...Models continue to be very
insistent...in good agreement and consistent over multiple
previous runs...in parking a deep upper level low smack dab over
the forecast area through most of the extended period. Thus
confidence is high in anticipation of a cool and periodically wet
forecast from mid-week onward through at least early next weekend.
The main uncertainties concern exactly where and when areas of
extra dynamic and deformation lift/focus will wind up...and thus
delineating periods of dense/frequent showers or downright
stratiform steady rain from periods of merely hit-and-miss or
intermittent showers. At this time it appears the Tuesday night
through Thursday morning time frame will be the wettest period
with the potential for a good deformation band slowly pivoting
from south to north through the entire region...potentially
bringing 3/4 of an inch or more of rain to the valleys of the
northern zones and Cascades. Even higher QPF is likely in the
mountains...but much of this will be locked up as a few inches of
wet snow above 4000 to 5000 feet through the period and
unavailable to swell rivers with mountain run-off.
There may be a few other periods of steadier showers over some
areas of the forecast area...but beyond Thursday the sub-synoptic
model details are suspect and inconsistent with each other in
nailing this down. Still...with this upper low taking up
residence it is certain that just about all zones will be at risk
for at least scattered showers each day through the end of the
week. The potential for thunderstorms is also possible...but this
will depend mainly on sun breaks allowing the generation of SB CAPE
during the afternoon hours and this prospect is too ephemeral to
nail down at this time.
The other main impact of this pattern will be high temperatures
well below normal for this time of year...while overnight lows
will probably remain only slightly cooler than normal given a
moist low level air mass and heavy clouds reducing radiation
potential. /Fugazzi
&&
.AVIATION...
12Z TAFS: High pressure moves across the region today. Patchy fog
will be found across ne WA/nrn ID through 15-17z, including in the
vcnty of the KGEG/KSFF/KCOE TAF sites. Otherwise dry/VFR
conditions are expected. Mid and high clouds increase from the
west late tonight into Tuesday morning as low pressure and a cold
front approach. /J. Cote`
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 71 51 75 43 51 38 / 0 0 10 80 90 40
Coeur d`Alene 71 46 77 45 48 39 / 0 0 10 70 90 50
Pullman 72 48 74 42 50 37 / 0 0 0 70 70 30
Lewiston 79 52 81 48 58 41 / 0 0 0 60 70 30
Colville 78 45 78 46 56 40 / 0 0 40 80 80 60
Sandpoint 71 44 77 45 52 39 / 10 0 20 70 80 70
Kellogg 70 50 76 44 46 37 / 10 0 10 60 90 70
Moses Lake 79 51 74 46 61 41 / 0 0 40 50 30 30
Wenatchee 77 53 67 46 58 43 / 0 0 50 60 40 40
Omak 78 47 71 46 60 40 / 0 0 70 90 70 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
000
FXUS66 KOTX 200918
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
218 AM PDT Mon May 20 2013
.SYNOPSIS...
High pressure will provide mainly dry, warm conditions today. A
strong storm system enters the region on Tuesday and Wednesday,
with a good threat of rain, and the potential for thunderstorms.
The system will also usher in significantly cooler temperatures.
Cool, showery weather will continue into the weekend.
&&
.DISCUSSION...
Today and tonight: The Inland Northwest will be mainly dry and
mild under the influence of high pressure, while a pattern-changing
trough approaches the coast. The flow transitions from northwest
to southwest by late this afternoon as the mid-level ridge axis
shifts into central ID and north CA. Lingering low-grade convective
instability is depicted around the Panhandle mountains this afternoon.
However broad-scale subsidence with the ridge should keep the threat
of showers in the mountains, if any occur at all. Otherwise the
higher clouds that are reaching over the Cascades this morning
will continue to spread in, coupled with some afternoon cumulus
build-up. The developing southwest flow and subsidence will
promote milder temperatures today as compared to Sunday. Look for
temperatures near to slightly above normal. Tonight low pressure
and a cold front comes toward Cascades while the long-wave trough
deepens and takes on a more meridional (north-south) orientation.
This will bring increasing rain chances to the Cascades overnight
and primarily near the crest. Elsewhere clouds will begin to
thicken and lower from the west. /J. Cote`
Tuesday and Tuesday Night: A strong low pressure system will finally
push into our region on Tuesday bringing with it the almost certain
chance of widespread rain for all of the Inland NW. This system
has been slowly moving down from the Gulf of Alaska and once in
place near the area will persist for quite some time. Quite a slug
of moisture looks to push inland with the initial barrage with the
brunt of the rainfall occurring near the crests of the Cascades
and later pushing further into the forecast area to bring lighter
amounts east of the crests.
Timing on this system looks to be in good agreement amongst the
models with all models showing the initial rainfall reaching the
Cascade crests by Tuesday morning and pushing further east
throughout the day Tuesday and into the evening for the ID
Panhandle. Ahead of the strong cold front will be some instability
that could trigger some thunderstorms for the eastern part of WA
and the ID panhandle in part due to the strong daytime heating due
to the southerly flow and an increased moisture push associated
with the incoming system. Once sunset occurs and overnight cooling
begins most all convection will come to an abrupt end...but the
rain showers will persist into the overnight hours. Snow levels remain
high until the cold front passes behind the initial rain which will
lead to a transition from rain to snow in the high elevations of
mainly the Cascades. With a bulk of the precip falling as rain we
will see an immediate rise in the local streams and rivers which
will be something we will continue to monitor. Although temps drop
after the passing of the cold front along with snow levels...the
lower snow levels will lead to less direct runoff in turn allowing
some storage of water and allowing streams to not rise as rapidly
as if all QPF fell as rain. Overall this time frame will be
characterized as a transition period from warm and dry to wet and
cool for the entire region. /Fliehman
Wednesday through Sunday...Models continue to be very
insistent...in good agreement and consistent over multiple
previous runs...in parking a deep upper level low smack dab over
the forecast area through most of the extended period. Thus
confidence is high in anticipation of a cool and periodically wet
forecast from mid-week onward through at least early next weekend.
The main uncertainties concern exactly where and when areas of
extra dynamic and deformation lift/focus will wind up...and thus
delineating periods of dense/frequent showers or downright
stratiform steady rain from periods of merely hit-and-miss or
intermittent showers. At this time it appears the Tuesday night
through Thursday morning time frame will be the wettest period
with the potential for a good deformation band slowly pivoting
from south to north through the entire region...potentially
bringing 3/4 of an inch or more of rain to the valleys of the
northern zones and Cascades. Even higher QPF is likely in the
mountains...but much of this will be locked up as a few inches of
wet snow above 4000 to 5000 feet through the period and
unavailable to swell rivers with mountain run-off.
There may be a few other periods of steadier showers over some
areas of the forecast area...but beyond Thursday the sub-synoptic
model details are suspect and inconsistent with each other in
nailing this down. Still...with this upper low taking up
residence it is certain that just about all zones will be at risk
for at least scattered showers each day through the end of the
week. The potential for thunderstorms is also possible...but this
will depend mainly on sun breaks allowing the generation of SB CAPE
during the afternoon hours and this prospect is too ephemeral to
nail down at this time.
The other main impact of this pattern will be high temperatures
well below normal for this time of year...while overnight lows
will probably remain only slightly cooler than normal given a
moist low level air mass and heavy clouds reducing radiation
potential. /Fugazzi
&&
.AVIATION...
06Z TAFS: High pressure will begin to build in tonight. This will
result in mid level cloud cover decreasing through this period
except for over the ID Panhandle. Patchy fog is expected to develop
in the mountain valleys across northeast WA and in the Northern
Panhandle. This will include stretches along the Spokane River,
which may result in a couple hours of reduced visibilities at KSFF
early in the morning around 12Z. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 71 51 75 43 51 38 / 0 0 10 80 90 40
Coeur d`Alene 71 46 77 45 48 39 / 0 0 10 70 90 50
Pullman 72 48 74 42 50 37 / 0 0 0 70 70 30
Lewiston 79 52 81 48 58 41 / 0 0 0 60 70 30
Colville 78 45 78 46 56 40 / 0 0 40 80 80 60
Sandpoint 71 44 77 45 52 39 / 10 0 20 70 80 70
Kellogg 70 50 76 44 46 37 / 10 0 10 60 90 70
Moses Lake 79 51 74 46 61 41 / 0 0 40 50 30 30
Wenatchee 77 53 67 46 58 43 / 0 0 50 60 40 40
Omak 78 47 71 46 60 40 / 0 0 70 90 70 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
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