La Niña Ends and Transitions to ENSO-Neutral

This winter marked the third year in a row with La Niña conditions in the equatorial Pacific Ocean, which is the cool phase of the El Niño-Southern Oscillation (ENSO) climate pattern. La Niña conditions were still in place through January and February, but exhibited signs of weakening with below-average sea surface temperatures weakening across the equatorial Pacific Ocean, as well as weakening negative subsurface temperature anomalies. As of early March, La Niña conditions persisted only in the central Pacific Ocean and the NWS Climate Prediction Center issued its final La Niña Advisory on March 9th. ENSO-neutral conditions are expected to persist through spring and early summer (March-May).

Models suggest increasing chances of a transition to El Niño during summer, but uncertainty remains high at longer forecast horizons. Indeed it is too early to say with certainty what will be the ENSO phase beyond spring. This time of year is notoriously difficult for forecasting ENSO long-term because of the so-called spring-time prediction barrier.

Latest Drought Status Update

La Niña winters tend to be warmer and drier than normal in Florida, and this pattern set in during winter this year. December monthly average temperatures were generally warmer than normal, except for a cold spell that impacted much of the state during the Christmas holiday. As we entered the new year, temperatures rebounded and have been unseasonably warm particularly throughout the month of February. We’re in the middle of the Florida dry season, but we’ve been running much drier than normal this winter. The map below shows the percent of normal precipitation during winter (DJF). Much of the Panhandle and Peninsula received about 50%-70% of normal precipitation this winter, and parts of the Peninsula and northeast Florida were below 50% of normal.

Winter Extremes Across Florida CoCoRaHS

Between 1 December 2022 and 28 February 2023:

• Highest seasonal rainfall total: 17.12" at Gonzalez, Escambia Co. (ES-15)
• Lowest seasonal rainfall total: 1.15" at Clewiston, Hendry Co. (HY-5)
• Highest daily rainfall total: 5.56" on February 5, 2023 at Key Largo, Monroe Co. (MN-35)

*based on data with 90% completeness

Seasonal Spring Outlook is Leaning Warmer and Drier than Normal for Florida

NOAA's Climate Prediction Center anticipates a warmer than normal spring season, from March through May, for Florida and across the southern tier of the U.S. Precipitation is leaning below normal across Florida, with central and southern Florida having between a 40% and 50% chance of below normal precipitation this spring. Drought is expected to persist across the Peninsula as we continue into the spring season.

The Importance of Significant Weather Reports

Significant Weather Reports (SWR's) submitted by CoCoRaHS observers are a huge help to the National Weather Service. All SWRs are automatically routed to the local NWS office, and forecasters use these reports to monitor the progress of storms. Questions we get from time to time are: "What is significant weather?" and "How often should I submit a Significant Weather report?". First, SWRs are supplementary reports and DO NOT replace your Daily Report nor should it be submitted in lieu of a Daily Report. The SWR is great for updating rainfall after your regular observation time. You should not update your daily report once it is submitted, except to make a correction or to add additional information. Comments included with your Significant Weather Report are also very useful.

It's the Dry Season: Be a Hero, Log Your Zeros!

Reporting zeros is really important when no rain has fallen. We realize that it takes time to enter your data daily and that a zero value may seem insignificant. However, a zero report is just as important as a non-zero. They help differentiate a site that actually received no rainfall from one where the observer simply didn’t make a report that day. With it being the dry season, these reports will be important as scientists continue to monitor the extent and duration of drought over the coming months! The U.S. Drought Monitor uses this information to better determine where drought is occurring and how agricultural interests may be affected.

Proper Gauge Siting

As we focus on recruitment this month, an important consideration for all new observers is where to set up your rain gauge. Location is the key to quality data. Please visit these resources to ensure that your gauge is properly placed.

https://www.cocorahs.org/Content.aspx?page=equip

https://media.cocorahs.org/docs/CoCoTrainingSlideshow_v10.1A.pdf

COCORAHS CELEBRATES 25 YEARS DURING 2023!