April 24, 2014
A cold front will spread showers and thunderstorms from the eastern
Plains to the Great Lakes on Thursday and Friday, but the Plains to
the Mississippi valley, WI, and IL will dry out on Friday with near to
slightly above normal temperatures. Much of the Plains and Midwest
will be dry on Saturday. A slow-moving storm will push across the
central and northern Plains Saturday night into Monday, then across
the Midwest on Monday into Wednesday. This storm will spread a swath
of moderate to heavy rainfall from the Dakotas and eastern NE to
eastern TX on Saturday night and Sunday with the trailing upper low
leading to scattered light showers from NE and northern KS to eastern
OK from Monday into Wednesday. Meanwhile, the surface storm will
spread moderate to heavy rainfall from the MS valley on eastward from
Sunday into Tuesday. The trailing upper low will lead to scattered
light to moderate rainfall across much of the Midwest into the TN
valley through Thursday. As the upper low drifts eastward the chance
of light showers will be confined to areas from WI and IL on eastward
next Friday and Saturday, while areas further west will have dry
weather with moderating temperatures. In the wake of the upper low,
the Plains and Midwest will have temperature moderating to seasonal
and slightly above normal levels. The warming will occur first across
the Plains late next week then the Midwest in the 11-15 day period.
The 11-15 day period looks a bit more active on the operational GFS,
but the ensembles are not as wet so still like the idea of near to
below normal rainfall in this period across the Plains and Midwest.
Dry and mild across much of California on Thursday. A strong trough
can bring the chance for rain as far south as the San Joaquin Valley
Friday into Saturday. A few light showers could even reach as far
south as SoCal on Saturday. These rain, while needed, will likely have
minimal impact on the ongoing severe drought across the state. A drier
and warmer than normal pattern is expected across CA next week.
High pressure will continue to promote dry weather across the
Argentina croplands through Saturday. A weak front will trigger
isolated light showers from BA and La Pampa to southern Cordoba on
Sunday. This front is expected to slow for a time over northern
Argentina early next week leading to the chance for scattered light to
moderate rainfall from northern BA to Cordoba on northward from Monday
into Wednesday. The heaviest rainfall is expected from Formosa to
Santiago Del Estero on eastward to Misiones and Corrientes. High
pressure will return with dry weather from Thursday through Saturday
of next week. The 11-15 day period across Argentina continues to look
drier than normal with temperatures likely averaging close to normal.
Across Brazil, high pressure will foster dry weather across RGS and SC
through Tuesday. A cold front lifting north will trigger scattered
light to moderate rainfall next Wednesday and Thursday, then drying
out again next Friday and Saturday. Isolated storms may persist
across SP and MGDS on Thursday, while Parana has dry weather.
Croplands in Parana, SP, and MGDS will be dry from Friday through next
Wednesday. Another front can lead to scattered light to moderate
rainfall late next week, but dry weather should return next weekend.
The ECWMF is slower lifting the front northward across southern Brazil
later next week and is therefore wetter than the GFS especially across
RGS and SC. However, stuck with a compromise timing and rainfall
forecast. Most croplands from RGS to SP and MGDS continue to look
drier than normal in the 11-15 day period. Croplands from Mato Grosso
to Minas Gerias will have widely separated showers and thunderstorms
each day through Friday. Most modeling continues to shows little, if
any, rainfall from Minas Gerias to Mato Grosso from this weekend into
next Thursday, but spotty storms can fire in far northern Mato Grosso
each day. An approaching front can lead to a few showers and storms
from Minas Gerias to Mato Grosso next Friday and Saturday.
Conditions will remain overall favorable for maize harvesting and
other fieldwork across South Africa through next week.
An active pattern will persist across Europe into early next week,
bringing some needed rainfall to central and northeast Europe.
These rains will help increase soil moisture levels following
recent drier than normal conditions.
Satellite imagery does show a highly disorganized area of showers and
thunderstorms located well to the southeast of Guam. If any tropical
development were to occur, it would happen slowly over the next
We are continuing to watch a cluster of showers and thunderstorms a
few hundred miles to the northeast of Darwin, Australia, in the
western Arafura Sea. Satellite imagery shows a blowup of thunderstorms
associated with this cluster over the last 8-12 hours. Despite the
fact these thunderstorms are over warm waters, stronger winds aloft
(upper level wind shear) continue to displace these thunderstorms away
from the low-level center. If the wind shear weakens a bit and the
thunderstorms are better able to wrap themselves about the low-level
center, further organization of this system will be possible over the
next 24-48 hours as it slowly drifts off to the southwest.