Wednesday, April 11, 2012

Wake Up Weather for April 12, 2012

Temperatures in the morning will be pretty chilly in the eastern half of the country, with many folks experiencing temperatures in the 30s and 40s across the Ohio Valley and Great Lakes into the Eastern Seaboard. However, out in the Plains, as a warm front moves eastward, temperatures will stand out into the 40s and even 50s as the sun rises. The warmest areas will be in Texas and Florida, where your morning temperatures will be in the 60s and 70s. Once again, the West Coast will wake up on the chilly side, with 20s and 30s in the mountains into the 40s by the coast itself.

As for precipitation, things should be relatively quiet in the East half of the US, although some spotty showers may be present in the Northeast as you wake up. The bigger rains will be in the Plains, where some rumbles of thunder are possible in north Texas and possibly into South Dakota and Nebraska. Oklahoma and Kansas will be in the mess however, with lighter rain falling in those states in the morning. Mountain snows will be the big story out west, with heavier snows in California. Don't be fooled in the lower elevations, as the coastal shore will get in on rain showers. Montana will get pretty messy too.

Overnight Forecast Discussion: April 11, 2012

Overnight Hotspot: Southern Plains
Some severe weather may be ongoing, especially in Texas, as a few frontal boundaries intersect in the state and combine to make for a messy, stormy situation.

The mountains will be full of messy weather, with snow in the mountains, rain in lower elevations and some mixing precipitation in between.

West Coast
On the coast, rain will be plentiful overnight, but mountain snows will once again be present, especially in northern California.

Some spotty rain showers are likely. No severe weather is expected.

Thunderstorm Outlook for Multi-Day Severe Weather Threat

Latest Information
As of now, indications are for a storm system to shift eastward and into the Plains. As this happens, a warm front already extended out ahead of the storm system will shift northward. At the same time, a cold front located west will move east and intercept the dry line in western Texas.
Due to several factors, including a sharp moisture gradient, high shearing levels and moderate instability, this situation has the potential to induce some intense or even tornadic severe thunderstorms.

Here is the thunderstorm outlook, valid April 12-16.

Yellow: Thunderstorms possible.
Orange: Stronger thunderstorms possible- some may become severe.
Red: Severe thunderstorms likely- a few clusters or several single cells are likely.
Pink: Intense severe weather likely- supercells and/or several intense storm clusters likely.
Blue: Catastrophic severe weather likely. Total destruction of some areas likely.

For those wondering:
Models used for this graphic: GFS, HPC Graphics, ECMWF, SPC SREF
(Models are labeled in order of most influence from left to right.)

Forecast Discussion: April 11, 2012

Hotspot of the Day: South Plains
A low pressure system will be ejecting eastward with a stationary front extending through Texas and along the Gulf Coast. This front will be the focus for severe weather today. Showers and thunderstorms are expected to also form along the trough extending from New Mexico north through Colorado and Wyoming. Both of these areas will have showers and storms to deal with, but it looks like the trough will be the one dealing with severe weather, with damaging winds and hail being the main threats.

West Coast
A storm system now onshore the US will be putting down massive amounts of rain and storms at lower elevations and snow in higher elevations. Some stronger storms are possible with this event today. Snow accumulations may exceed 1 foot above 7000 feet, and 12 inches or under below 7000 feet.

An offshore storm system will be putting down rain and snow showers throughout the region today. However, little to no accumulation appears to be expected.

North Plains
A storm system in the region and a warm front out ahead of the system will make for very windy conditions in the Dakotas and east Montana today. This may provoke fire danger.

With rain moving through the area in the Southwest, eastern areas of the Southwest will be dry, despite a long trough moving east followed by a cold front. I would anticipate some clouds due to the presence of these disturbances.