Forecast Discussions mentioning any of
"ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 01/14/21
Area Forecast Discussion...Updated
National Weather Service Phoenix AZ
420 PM MST Wed Jan 13 2021
.UPDATE...Updated aviation discussion.
&&
.SYNOPSIS...
A warming trend will begin in southeast California and far
southwest Arizona today and expand to south-central Arizona
Thursday. That will mean highs on the lower deserts reaching the
mid 70s to low 80s. Anticipate little change in temperatures
Friday and Saturday. It will be breezy at times Thursday and
Saturday, mainly over portions of southwest Arizona and southeast
California. During the first half of next week there will be a
significant cooling trend along with breezy to windy
conditions, most noticeably on Monday and Tuesday. However,
precipitation chances will be slight and limited to the higher
terrain of south-central Arizona on Tuesday.
&&
.DISCUSSION...
It was another chilly morning with Sky Harbor dropping to 38
degrees, which ties for the coldest temperature so far this
winter. Isolated areas of Pinal County also dropped into the upper
20s, owing to below normal dewpoints in the low teens.
High clouds continue to spill over into the Desert Southwest
within a northwesterly flow around an anticyclone in the eastern
Pacific. Meanwhile, latest ACARS soundings indicate some warming
through the entire column. Additional warming is anticipated the
next few days as the ridge amplifies along the west coast. Latest
NBM indicates temperatures in Yuma will flirt with daily records
Thursday through Saturday, which are generally in the lower 80s
each day. Most probable day to tie or break a daily record will be
Thursday at 55%, when the record high is 80 degrees, last set in
2000. Further east in Phoenix, temperatures will likely peak in
the upper 70s and several degrees shy of records. Models continue
to indicate another weak trough will pass through the Four Corners
region Saturday. Some breeziness is anticipated down the Colorado
River Valley. Otherwise, impacts will be negligible.
Latest GEFS and ECM ensemble mean continue to suggest the pattern will
amplify across the western CONUS early next week, with a deepening
area of low pressure and strong negative height anomalies
dropping southward into Arizona. EMC ensemble still indicates a
considerable amount of uncertainty, though trends are towards a
stronger system. However, even the weakest member would result in
a system capable of producing a cool down and breezy conditions.
NCEP cluster analysis indicates the strongest solution is also the
most likely. The GEFS members are certainly wetter than the ECM
members, with one of the members even suggesting over an inch of
QPF. However, QPF cannot be ruled out and this bears watching,
even as far west as Yuma. Better bet is for windy conditions,
particularly down the Colorado River Valley Monday and Tuesday.
Strong wind gusts may also be capable of producing areas of
blowing dust each day.
&&
.AVIATION...Updated at 2320Z.
South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Southeast California/Southwest Arizona including KIPL and KBLH:
There are no aviation concerns at the terminals over the next 24
hours at least as high pressure aloft will dominate the weather
pattern. This is very much a persistence pattern especially in the
Phoenix area, with wind/sky conditions similar to the past few days.
Look for light diurnal winds in the Phoenix area through Thursday
evening along with decreasing high cirrus. Winds out west will be
light tonight with some increase in north winds down the lower
Colorado River valley starting by mid morning Thursday. Expect some
gusts to 20kt at KBLH by Thursday afternoon from the north.
&&
.FIRE WEATHER...
Friday through Tuesday...
Well above normal temperatures continue Friday and Saturday.
Anticipate another round of northerly breeziness on Saturday (less
so over the lower elevations of south-central AZ). Humidities will
remain low on those days with Min RH readings in the 10-15%
range and Max RH in the 25-40% range. the first half of next week
will see a significant cooling trend along with windy conditions
at times. The most significant winds and cooling are anticipated
in the Monday-Tuesday time frame. The system will be moisture
starved with precipitation potential limited to slight chances
over the higher terrain of south-central AZ on Tuesday. Anticipate
only a modest increase in Min RH (mainly Tuesday over the higher
terrain of south-central AZ). Overnight recovery looks to be only
fair at best given the lingering overnight breeziness. Conditions
may approach critical thresholds in the afternoons in some
isolated spots on Monday and Tuesday.
&&
.Climate...
Record highs Thursday and Friday:
Date Phoenix Yuma El Centro
---- ------- ---- ---------
Jan 14 81 in 2000 80 in 2000 85 in 1943
Jan 15 81 in 2000 81 in 1943 85 in 1926
&&
.SPOTTER INFORMATION STATEMENT...
Spotters should follow standard reporting procedures.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
DISCUSSION...Hirsch
AVIATION...CB
FIRE WEATHER...AJ
CLIMATE...MO