Tropical Development Likely in Caribbean for July 4th

I believe we are likely to see tropical development in the Caribbean and/or Gulf of Mexico in the first 7 days of July. This comes as the atmosphere primes itself for a very tropically-conducive upper air pattern in these same regions.

The latest GFS model had a substantial tropical cyclone present in the Gulf of Mexico on July 1st, with landfall occurring in western Louisiana the morning of July 2nd. Pressure readings would drop below 1000 millibars in the open waters before rising as landfall occurs, as shown in the image above.

I'm really pushing for the likelihood of development in the Gulf of Mexico and/or Caribbean because the atmosphere is going to be truly primed for tropical cyclone formation to start the month of July. Global models are now agreeing on the development of a very strong Madden-Julian Oscillation event in the Eastern Pacific into the western Atlantic. This includes the Gulf of Mexico and Caribbean. This strong MJO event means enhanced chances for tropical convection in these areas. If the tropical convection from this MJO event combines with the favorable mid-level atmospheric flow being sustained by the large high pressure system over the United States (which is likely to occur), tropical development would be expected.

At this point in time, I would anticipate development to occur either in the Western Caribbean or in the Gulf of Mexico; I don't find it too likely that we would see a cyclone make its way through the entire Caribbean and Gulf of Mexico when the most conducive conditions are closer to the US Mainland. Corpus Christi TX, Houston TX, New Orleans LA, Mobile AL and Pensacola FL could all be affected by a tropical cyclone forming in the Gulf of Mexico.

Andrew

Short Range Risk Analysis - June 19, 2013

This Short Range Risk Analysis, made on June 19th, covers the timeframe of now to 5-7 days from today. Confidence on this analysis is Above Average.

Overall Synopsis
Large closed low over the Pacific Northwest is enabling high pressure formation over the Northern Plains, advecting instability and conditions supportive for severe weather. Ridging pattern appears to be ongoing in this timeframe from the Ohio Valley eastward, allowing for a rather quiet period for the East.

Severe Weather Outlook: Medium/High Activity
Confidence: Average
Uncertainty in previous Short Range Risk Analysis has been greatly cleared up, allowing me to see the nature of the severe weather threats in the next 5-7 days. Model guidance is confirming pieces of energy from the closed low in the Pacific Northwest will slide east and interact with ridging high pressure over the Northern Plains to create multiple severe weather opportunities in that area. Progression of the severe weather threat moves east and south by the 3 day forecast mark, with the Storm Prediction Center placing a large portion of the Midwest and Upper Plains under the gun for severe weather. Threat should continue to the end of the 7 day mark in this short range analysis, leading the outlook to a Medium/High Activity level with Average confidence.

Flooding Outlook: Medium Activity
Confidence: Above Average
Ongoing severe weather events will span multiple days across the Upper Plains, particularly from North Dakota and Minnesota to Wisconsin. Current model guidance has multiple places in these states receiving up to 6.00 inches of rain in roughly 6 days. The multiple bouts of potentially strong storms will allow for multiple days of stress on rivers. While no major flooding is currently ongoing in the areas mentioned, 6 inches of rain in 6 days is enough to put at least considerable stress on some rivers.

Heat Outlook: Medium Activity
Confidence: Very Above Average
The presence of a closed low in the Pacific Northwest has led to some high pressure development in the Northern Plains. Amplification of this high pressure to include additional areas of the Plains and Midwest is expected, with more high pressure formation occurring in the Eastern US. Coagulation into a single high pressure system is expected over time, which will push the jet stream into a zonal flow and move it north. This zonal flow will allow warmer weather to shift north into the United States, and massive high pressure will enhance that job at the 7 day mark and a little bit beyond. Confidence is Very Above Average in the Medium Activity outlook for heat, as model guidance has been consistent on large high pressure formation for days.

Tropical Outlook: Low Activity
Confidence: Average
Tropical Depression TWO continues to shift towards Mexico, dumping heavy rain across the area. Redevelopment of this depression into a tropical storm was previously expected by the National Hurricane Center, and development into a tropical storm is now expected by the agency as soon as this afternoon. I remain skeptical on the idea considering how close to land the depression is, but as the depression slows down and seemed to get its act together in the evening hours last night, I can see how strengthening can be a possibility. However, Low Activity is listed for this outlook, as no development is anticipated following TD-TWO.

Andrew

Short Range Risk Analysis - June 17, 2013

This Short Range Risk Analysis covers the time period from now until the next 3-5 days. Confidence in this full analysis is Average.

Overall Synopsis
Tropical Depression TWO has developed in the western Caribbean and is expected to make landfall in the next couple of days. Multiple severe weather chances will arise over the next few days, although their significance is in question as the active weather we have seen in the last few weeks starts to stagnate.

Severe Weather Outlook: Low/Medium Activity
Confidence: Above Normal
Today and tomorrow will feature severe weather chances in the Southern Plains, with Montana on watch the day after tomorrow. Despite these areas of concern, the next 3-5 days does not feature any areas where severe weather is expected to reach intense levels. Activity in this timeframe is thus described as Low/Medium.

Heat Outlook: Medium Activity
Confidence: Below Normal
Medium range forecast calls for the development of high pressure over the Plains as a closed low system enters the Pacific Northwest. Multiple sources indicate this ridge will arise in the next 2-3 days, extending into the full 3-5 day period of this outlook. The intensity of this ridge in its beginning days remains in question, leaving confidence in the below normal stage. The presence of this ridging pattern will allow heat to move further into the Plains during this timeframe, however, meaning the Heat outlook is at Medium activity.

Tropical Outlook: Low Activity
Confidence: Average
Tropical Depression TWO has developed in the Atlantic in the last few hours, with its origin to the east of the Yucatan Peninsula. Intensity of this depression is low, as it is only a depression. This system is expected to maintain its tropical depression status until and after landfall on the Yucatan Peninsula. After departing the Yucatan Peninsula moving west-northwest, the National Hurricane Center indicates strengthening into a tropical storm is possible before a second landfall on Mexico is observed. While I am skeptical of this storm strengthening after its first landfall, I am confident that the United States will not be affected, thus the tropical outlook has a Low activity forecast.

Andrew

Long Range Risk Analysis - June 16, 2013

 Note: This is a new idea I had for delivering text-based messages about long range risks (varying by season) to the public. This is an example of what would be issued (while it's an example, the information is an actual forecast). Feedback is welcome.

Outlook valid for the next 15-20 days.

Overall Synopsis
Closed low coming onshore in the Pacific Northwest will allow prolonged high pressure development in the Plains, eventually extending into the Midwest. Closed low eventually is torn up and leads to zonal flow across the United States before re-emergence of prolonged high pressure development,

Severe Weather Outlook: Low/Medium Activity
Closed low entering Pacific Northwest will allow severe weather opportunities in the Southern Plains, limited only to Texas and New Mexico into Colorado at this time. Northern Plains may become involved for a short period with low expectations in a couple of days. Long range outlook becomes quiet as zonal flow takes over before the risk of severe weather goes on the upswing as we enter prolonged ridging over the Plains.

Heat Outlook: High Activity
Two periods of prolonged high pressure formation in the Plains and portions of Midwest will lead to increased flows of heat north into mainly the Plains area. Eventual zonal flow and long range Death Ridge formation potential may allow this heat to openly enter much of the nation. Long range outlook remains unusually toasty in this scenario.

Tropical Outlook: Low Activity
Lack of enhanced tropical convection over the Atlantic basin will not permit any sustained tropical cyclone formation. Current area of interest (Invest 93) is moving on land, and next chance at development appears to be over 10 days away.

Andrew

Special Weather Notice - OK/TX/KS/NE/CO/SD - June 16, 2013

A Special Weather Notice has been issued by The Weather Centre for the following areas:

-Oklahoma
-North Texas
-West Kansas
-East Colorado
-Nebraska
-South Dakota

Severe thunderstorms are beginning to form in the highlighted areas. The Storm Prediction Center has issued a severe thunderstorm watch for central and western Nebraska, and additional watches are pending for many of the highlighted regions.

Expected threats to those in the mentioned states are:

-Hail
-Damaging wind gusts
-Isolated tornado potential

Andrew